linux/drivers/clk/clk.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
   4 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
   5 *
   6 * Standard functionality for the common clock API.  See Documentation/driver-api/clk.rst
   7 */
   8
   9#include <linux/clk.h>
  10#include <linux/clk-provider.h>
  11#include <linux/clk/clk-conf.h>
  12#include <linux/module.h>
  13#include <linux/mutex.h>
  14#include <linux/spinlock.h>
  15#include <linux/err.h>
  16#include <linux/list.h>
  17#include <linux/slab.h>
  18#include <linux/of.h>
  19#include <linux/device.h>
  20#include <linux/init.h>
  21#include <linux/pm_runtime.h>
  22#include <linux/sched.h>
  23#include <linux/clkdev.h>
  24
  25#include "clk.h"
  26
  27static DEFINE_SPINLOCK(enable_lock);
  28static DEFINE_MUTEX(prepare_lock);
  29
  30static struct task_struct *prepare_owner;
  31static struct task_struct *enable_owner;
  32
  33static int prepare_refcnt;
  34static int enable_refcnt;
  35
  36static HLIST_HEAD(clk_root_list);
  37static HLIST_HEAD(clk_orphan_list);
  38static LIST_HEAD(clk_notifier_list);
  39
  40static struct hlist_head *all_lists[] = {
  41        &clk_root_list,
  42        &clk_orphan_list,
  43        NULL,
  44};
  45
  46/***    private data structures    ***/
  47
  48struct clk_parent_map {
  49        const struct clk_hw     *hw;
  50        struct clk_core         *core;
  51        const char              *fw_name;
  52        const char              *name;
  53        int                     index;
  54};
  55
  56struct clk_core {
  57        const char              *name;
  58        const struct clk_ops    *ops;
  59        struct clk_hw           *hw;
  60        struct module           *owner;
  61        struct device           *dev;
  62        struct device_node      *of_node;
  63        struct clk_core         *parent;
  64        struct clk_parent_map   *parents;
  65        u8                      num_parents;
  66        u8                      new_parent_index;
  67        unsigned long           rate;
  68        unsigned long           req_rate;
  69        unsigned long           new_rate;
  70        struct clk_core         *new_parent;
  71        struct clk_core         *new_child;
  72        unsigned long           flags;
  73        bool                    orphan;
  74        bool                    rpm_enabled;
  75        unsigned int            enable_count;
  76        unsigned int            prepare_count;
  77        unsigned int            protect_count;
  78        unsigned long           min_rate;
  79        unsigned long           max_rate;
  80        unsigned long           accuracy;
  81        int                     phase;
  82        struct clk_duty         duty;
  83        struct hlist_head       children;
  84        struct hlist_node       child_node;
  85        struct hlist_head       clks;
  86        unsigned int            notifier_count;
  87#ifdef CONFIG_DEBUG_FS
  88        struct dentry           *dentry;
  89        struct hlist_node       debug_node;
  90#endif
  91        struct kref             ref;
  92};
  93
  94#define CREATE_TRACE_POINTS
  95#include <trace/events/clk.h>
  96
  97struct clk {
  98        struct clk_core *core;
  99        struct device *dev;
 100        const char *dev_id;
 101        const char *con_id;
 102        unsigned long min_rate;
 103        unsigned long max_rate;
 104        unsigned int exclusive_count;
 105        struct hlist_node clks_node;
 106};
 107
 108/***           runtime pm          ***/
 109static int clk_pm_runtime_get(struct clk_core *core)
 110{
 111        int ret;
 112
 113        if (!core->rpm_enabled)
 114                return 0;
 115
 116        ret = pm_runtime_get_sync(core->dev);
 117        if (ret < 0) {
 118                pm_runtime_put_noidle(core->dev);
 119                return ret;
 120        }
 121        return 0;
 122}
 123
 124static void clk_pm_runtime_put(struct clk_core *core)
 125{
 126        if (!core->rpm_enabled)
 127                return;
 128
 129        pm_runtime_put_sync(core->dev);
 130}
 131
 132/***           locking             ***/
 133static void clk_prepare_lock(void)
 134{
 135        if (!mutex_trylock(&prepare_lock)) {
 136                if (prepare_owner == current) {
 137                        prepare_refcnt++;
 138                        return;
 139                }
 140                mutex_lock(&prepare_lock);
 141        }
 142        WARN_ON_ONCE(prepare_owner != NULL);
 143        WARN_ON_ONCE(prepare_refcnt != 0);
 144        prepare_owner = current;
 145        prepare_refcnt = 1;
 146}
 147
 148static void clk_prepare_unlock(void)
 149{
 150        WARN_ON_ONCE(prepare_owner != current);
 151        WARN_ON_ONCE(prepare_refcnt == 0);
 152
 153        if (--prepare_refcnt)
 154                return;
 155        prepare_owner = NULL;
 156        mutex_unlock(&prepare_lock);
 157}
 158
 159static unsigned long clk_enable_lock(void)
 160        __acquires(enable_lock)
 161{
 162        unsigned long flags;
 163
 164        /*
 165         * On UP systems, spin_trylock_irqsave() always returns true, even if
 166         * we already hold the lock. So, in that case, we rely only on
 167         * reference counting.
 168         */
 169        if (!IS_ENABLED(CONFIG_SMP) ||
 170            !spin_trylock_irqsave(&enable_lock, flags)) {
 171                if (enable_owner == current) {
 172                        enable_refcnt++;
 173                        __acquire(enable_lock);
 174                        if (!IS_ENABLED(CONFIG_SMP))
 175                                local_save_flags(flags);
 176                        return flags;
 177                }
 178                spin_lock_irqsave(&enable_lock, flags);
 179        }
 180        WARN_ON_ONCE(enable_owner != NULL);
 181        WARN_ON_ONCE(enable_refcnt != 0);
 182        enable_owner = current;
 183        enable_refcnt = 1;
 184        return flags;
 185}
 186
 187static void clk_enable_unlock(unsigned long flags)
 188        __releases(enable_lock)
 189{
 190        WARN_ON_ONCE(enable_owner != current);
 191        WARN_ON_ONCE(enable_refcnt == 0);
 192
 193        if (--enable_refcnt) {
 194                __release(enable_lock);
 195                return;
 196        }
 197        enable_owner = NULL;
 198        spin_unlock_irqrestore(&enable_lock, flags);
 199}
 200
 201static bool clk_core_rate_is_protected(struct clk_core *core)
 202{
 203        return core->protect_count;
 204}
 205
 206static bool clk_core_is_prepared(struct clk_core *core)
 207{
 208        bool ret = false;
 209
 210        /*
 211         * .is_prepared is optional for clocks that can prepare
 212         * fall back to software usage counter if it is missing
 213         */
 214        if (!core->ops->is_prepared)
 215                return core->prepare_count;
 216
 217        if (!clk_pm_runtime_get(core)) {
 218                ret = core->ops->is_prepared(core->hw);
 219                clk_pm_runtime_put(core);
 220        }
 221
 222        return ret;
 223}
 224
 225static bool clk_core_is_enabled(struct clk_core *core)
 226{
 227        bool ret = false;
 228
 229        /*
 230         * .is_enabled is only mandatory for clocks that gate
 231         * fall back to software usage counter if .is_enabled is missing
 232         */
 233        if (!core->ops->is_enabled)
 234                return core->enable_count;
 235
 236        /*
 237         * Check if clock controller's device is runtime active before
 238         * calling .is_enabled callback. If not, assume that clock is
 239         * disabled, because we might be called from atomic context, from
 240         * which pm_runtime_get() is not allowed.
 241         * This function is called mainly from clk_disable_unused_subtree,
 242         * which ensures proper runtime pm activation of controller before
 243         * taking enable spinlock, but the below check is needed if one tries
 244         * to call it from other places.
 245         */
 246        if (core->rpm_enabled) {
 247                pm_runtime_get_noresume(core->dev);
 248                if (!pm_runtime_active(core->dev)) {
 249                        ret = false;
 250                        goto done;
 251                }
 252        }
 253
 254        ret = core->ops->is_enabled(core->hw);
 255done:
 256        if (core->rpm_enabled)
 257                pm_runtime_put(core->dev);
 258
 259        return ret;
 260}
 261
 262/***    helper functions   ***/
 263
 264const char *__clk_get_name(const struct clk *clk)
 265{
 266        return !clk ? NULL : clk->core->name;
 267}
 268EXPORT_SYMBOL_GPL(__clk_get_name);
 269
 270const char *clk_hw_get_name(const struct clk_hw *hw)
 271{
 272        return hw->core->name;
 273}
 274EXPORT_SYMBOL_GPL(clk_hw_get_name);
 275
 276struct clk_hw *__clk_get_hw(struct clk *clk)
 277{
 278        return !clk ? NULL : clk->core->hw;
 279}
 280EXPORT_SYMBOL_GPL(__clk_get_hw);
 281
 282unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
 283{
 284        return hw->core->num_parents;
 285}
 286EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
 287
 288struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
 289{
 290        return hw->core->parent ? hw->core->parent->hw : NULL;
 291}
 292EXPORT_SYMBOL_GPL(clk_hw_get_parent);
 293
 294static struct clk_core *__clk_lookup_subtree(const char *name,
 295                                             struct clk_core *core)
 296{
 297        struct clk_core *child;
 298        struct clk_core *ret;
 299
 300        if (!strcmp(core->name, name))
 301                return core;
 302
 303        hlist_for_each_entry(child, &core->children, child_node) {
 304                ret = __clk_lookup_subtree(name, child);
 305                if (ret)
 306                        return ret;
 307        }
 308
 309        return NULL;
 310}
 311
 312static struct clk_core *clk_core_lookup(const char *name)
 313{
 314        struct clk_core *root_clk;
 315        struct clk_core *ret;
 316
 317        if (!name)
 318                return NULL;
 319
 320        /* search the 'proper' clk tree first */
 321        hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
 322                ret = __clk_lookup_subtree(name, root_clk);
 323                if (ret)
 324                        return ret;
 325        }
 326
 327        /* if not found, then search the orphan tree */
 328        hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
 329                ret = __clk_lookup_subtree(name, root_clk);
 330                if (ret)
 331                        return ret;
 332        }
 333
 334        return NULL;
 335}
 336
 337#ifdef CONFIG_OF
 338static int of_parse_clkspec(const struct device_node *np, int index,
 339                            const char *name, struct of_phandle_args *out_args);
 340static struct clk_hw *
 341of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec);
 342#else
 343static inline int of_parse_clkspec(const struct device_node *np, int index,
 344                                   const char *name,
 345                                   struct of_phandle_args *out_args)
 346{
 347        return -ENOENT;
 348}
 349static inline struct clk_hw *
 350of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
 351{
 352        return ERR_PTR(-ENOENT);
 353}
 354#endif
 355
 356/**
 357 * clk_core_get - Find the clk_core parent of a clk
 358 * @core: clk to find parent of
 359 * @p_index: parent index to search for
 360 *
 361 * This is the preferred method for clk providers to find the parent of a
 362 * clk when that parent is external to the clk controller. The parent_names
 363 * array is indexed and treated as a local name matching a string in the device
 364 * node's 'clock-names' property or as the 'con_id' matching the device's
 365 * dev_name() in a clk_lookup. This allows clk providers to use their own
 366 * namespace instead of looking for a globally unique parent string.
 367 *
 368 * For example the following DT snippet would allow a clock registered by the
 369 * clock-controller@c001 that has a clk_init_data::parent_data array
 370 * with 'xtal' in the 'name' member to find the clock provided by the
 371 * clock-controller@f00abcd without needing to get the globally unique name of
 372 * the xtal clk.
 373 *
 374 *      parent: clock-controller@f00abcd {
 375 *              reg = <0xf00abcd 0xabcd>;
 376 *              #clock-cells = <0>;
 377 *      };
 378 *
 379 *      clock-controller@c001 {
 380 *              reg = <0xc001 0xf00d>;
 381 *              clocks = <&parent>;
 382 *              clock-names = "xtal";
 383 *              #clock-cells = <1>;
 384 *      };
 385 *
 386 * Returns: -ENOENT when the provider can't be found or the clk doesn't
 387 * exist in the provider or the name can't be found in the DT node or
 388 * in a clkdev lookup. NULL when the provider knows about the clk but it
 389 * isn't provided on this system.
 390 * A valid clk_core pointer when the clk can be found in the provider.
 391 */
 392static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index)
 393{
 394        const char *name = core->parents[p_index].fw_name;
 395        int index = core->parents[p_index].index;
 396        struct clk_hw *hw = ERR_PTR(-ENOENT);
 397        struct device *dev = core->dev;
 398        const char *dev_id = dev ? dev_name(dev) : NULL;
 399        struct device_node *np = core->of_node;
 400        struct of_phandle_args clkspec;
 401
 402        if (np && (name || index >= 0) &&
 403            !of_parse_clkspec(np, index, name, &clkspec)) {
 404                hw = of_clk_get_hw_from_clkspec(&clkspec);
 405                of_node_put(clkspec.np);
 406        } else if (name) {
 407                /*
 408                 * If the DT search above couldn't find the provider fallback to
 409                 * looking up via clkdev based clk_lookups.
 410                 */
 411                hw = clk_find_hw(dev_id, name);
 412        }
 413
 414        if (IS_ERR(hw))
 415                return ERR_CAST(hw);
 416
 417        return hw->core;
 418}
 419
 420static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
 421{
 422        struct clk_parent_map *entry = &core->parents[index];
 423        struct clk_core *parent;
 424
 425        if (entry->hw) {
 426                parent = entry->hw->core;
 427                /*
 428                 * We have a direct reference but it isn't registered yet?
 429                 * Orphan it and let clk_reparent() update the orphan status
 430                 * when the parent is registered.
 431                 */
 432                if (!parent)
 433                        parent = ERR_PTR(-EPROBE_DEFER);
 434        } else {
 435                parent = clk_core_get(core, index);
 436                if (PTR_ERR(parent) == -ENOENT && entry->name)
 437                        parent = clk_core_lookup(entry->name);
 438        }
 439
 440        /* Only cache it if it's not an error */
 441        if (!IS_ERR(parent))
 442                entry->core = parent;
 443}
 444
 445static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
 446                                                         u8 index)
 447{
 448        if (!core || index >= core->num_parents || !core->parents)
 449                return NULL;
 450
 451        if (!core->parents[index].core)
 452                clk_core_fill_parent_index(core, index);
 453
 454        return core->parents[index].core;
 455}
 456
 457struct clk_hw *
 458clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
 459{
 460        struct clk_core *parent;
 461
 462        parent = clk_core_get_parent_by_index(hw->core, index);
 463
 464        return !parent ? NULL : parent->hw;
 465}
 466EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
 467
 468unsigned int __clk_get_enable_count(struct clk *clk)
 469{
 470        return !clk ? 0 : clk->core->enable_count;
 471}
 472
 473static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
 474{
 475        if (!core)
 476                return 0;
 477
 478        if (!core->num_parents || core->parent)
 479                return core->rate;
 480
 481        /*
 482         * Clk must have a parent because num_parents > 0 but the parent isn't
 483         * known yet. Best to return 0 as the rate of this clk until we can
 484         * properly recalc the rate based on the parent's rate.
 485         */
 486        return 0;
 487}
 488
 489unsigned long clk_hw_get_rate(const struct clk_hw *hw)
 490{
 491        return clk_core_get_rate_nolock(hw->core);
 492}
 493EXPORT_SYMBOL_GPL(clk_hw_get_rate);
 494
 495static unsigned long clk_core_get_accuracy_no_lock(struct clk_core *core)
 496{
 497        if (!core)
 498                return 0;
 499
 500        return core->accuracy;
 501}
 502
 503unsigned long clk_hw_get_flags(const struct clk_hw *hw)
 504{
 505        return hw->core->flags;
 506}
 507EXPORT_SYMBOL_GPL(clk_hw_get_flags);
 508
 509bool clk_hw_is_prepared(const struct clk_hw *hw)
 510{
 511        return clk_core_is_prepared(hw->core);
 512}
 513EXPORT_SYMBOL_GPL(clk_hw_is_prepared);
 514
 515bool clk_hw_rate_is_protected(const struct clk_hw *hw)
 516{
 517        return clk_core_rate_is_protected(hw->core);
 518}
 519EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected);
 520
 521bool clk_hw_is_enabled(const struct clk_hw *hw)
 522{
 523        return clk_core_is_enabled(hw->core);
 524}
 525EXPORT_SYMBOL_GPL(clk_hw_is_enabled);
 526
 527bool __clk_is_enabled(struct clk *clk)
 528{
 529        if (!clk)
 530                return false;
 531
 532        return clk_core_is_enabled(clk->core);
 533}
 534EXPORT_SYMBOL_GPL(__clk_is_enabled);
 535
 536static bool mux_is_better_rate(unsigned long rate, unsigned long now,
 537                           unsigned long best, unsigned long flags)
 538{
 539        if (flags & CLK_MUX_ROUND_CLOSEST)
 540                return abs(now - rate) < abs(best - rate);
 541
 542        return now <= rate && now > best;
 543}
 544
 545int clk_mux_determine_rate_flags(struct clk_hw *hw,
 546                                 struct clk_rate_request *req,
 547                                 unsigned long flags)
 548{
 549        struct clk_core *core = hw->core, *parent, *best_parent = NULL;
 550        int i, num_parents, ret;
 551        unsigned long best = 0;
 552        struct clk_rate_request parent_req = *req;
 553
 554        /* if NO_REPARENT flag set, pass through to current parent */
 555        if (core->flags & CLK_SET_RATE_NO_REPARENT) {
 556                parent = core->parent;
 557                if (core->flags & CLK_SET_RATE_PARENT) {
 558                        ret = __clk_determine_rate(parent ? parent->hw : NULL,
 559                                                   &parent_req);
 560                        if (ret)
 561                                return ret;
 562
 563                        best = parent_req.rate;
 564                } else if (parent) {
 565                        best = clk_core_get_rate_nolock(parent);
 566                } else {
 567                        best = clk_core_get_rate_nolock(core);
 568                }
 569
 570                goto out;
 571        }
 572
 573        /* find the parent that can provide the fastest rate <= rate */
 574        num_parents = core->num_parents;
 575        for (i = 0; i < num_parents; i++) {
 576                parent = clk_core_get_parent_by_index(core, i);
 577                if (!parent)
 578                        continue;
 579
 580                if (core->flags & CLK_SET_RATE_PARENT) {
 581                        parent_req = *req;
 582                        ret = __clk_determine_rate(parent->hw, &parent_req);
 583                        if (ret)
 584                                continue;
 585                } else {
 586                        parent_req.rate = clk_core_get_rate_nolock(parent);
 587                }
 588
 589                if (mux_is_better_rate(req->rate, parent_req.rate,
 590                                       best, flags)) {
 591                        best_parent = parent;
 592                        best = parent_req.rate;
 593                }
 594        }
 595
 596        if (!best_parent)
 597                return -EINVAL;
 598
 599out:
 600        if (best_parent)
 601                req->best_parent_hw = best_parent->hw;
 602        req->best_parent_rate = best;
 603        req->rate = best;
 604
 605        return 0;
 606}
 607EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
 608
 609struct clk *__clk_lookup(const char *name)
 610{
 611        struct clk_core *core = clk_core_lookup(name);
 612
 613        return !core ? NULL : core->hw->clk;
 614}
 615
 616static void clk_core_get_boundaries(struct clk_core *core,
 617                                    unsigned long *min_rate,
 618                                    unsigned long *max_rate)
 619{
 620        struct clk *clk_user;
 621
 622        lockdep_assert_held(&prepare_lock);
 623
 624        *min_rate = core->min_rate;
 625        *max_rate = core->max_rate;
 626
 627        hlist_for_each_entry(clk_user, &core->clks, clks_node)
 628                *min_rate = max(*min_rate, clk_user->min_rate);
 629
 630        hlist_for_each_entry(clk_user, &core->clks, clks_node)
 631                *max_rate = min(*max_rate, clk_user->max_rate);
 632}
 633
 634void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
 635                           unsigned long max_rate)
 636{
 637        hw->core->min_rate = min_rate;
 638        hw->core->max_rate = max_rate;
 639}
 640EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
 641
 642/*
 643 * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk
 644 * @hw: mux type clk to determine rate on
 645 * @req: rate request, also used to return preferred parent and frequencies
 646 *
 647 * Helper for finding best parent to provide a given frequency. This can be used
 648 * directly as a determine_rate callback (e.g. for a mux), or from a more
 649 * complex clock that may combine a mux with other operations.
 650 *
 651 * Returns: 0 on success, -EERROR value on error
 652 */
 653int __clk_mux_determine_rate(struct clk_hw *hw,
 654                             struct clk_rate_request *req)
 655{
 656        return clk_mux_determine_rate_flags(hw, req, 0);
 657}
 658EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
 659
 660int __clk_mux_determine_rate_closest(struct clk_hw *hw,
 661                                     struct clk_rate_request *req)
 662{
 663        return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
 664}
 665EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
 666
 667/***        clk api        ***/
 668
 669static void clk_core_rate_unprotect(struct clk_core *core)
 670{
 671        lockdep_assert_held(&prepare_lock);
 672
 673        if (!core)
 674                return;
 675
 676        if (WARN(core->protect_count == 0,
 677            "%s already unprotected\n", core->name))
 678                return;
 679
 680        if (--core->protect_count > 0)
 681                return;
 682
 683        clk_core_rate_unprotect(core->parent);
 684}
 685
 686static int clk_core_rate_nuke_protect(struct clk_core *core)
 687{
 688        int ret;
 689
 690        lockdep_assert_held(&prepare_lock);
 691
 692        if (!core)
 693                return -EINVAL;
 694
 695        if (core->protect_count == 0)
 696                return 0;
 697
 698        ret = core->protect_count;
 699        core->protect_count = 1;
 700        clk_core_rate_unprotect(core);
 701
 702        return ret;
 703}
 704
 705/**
 706 * clk_rate_exclusive_put - release exclusivity over clock rate control
 707 * @clk: the clk over which the exclusivity is released
 708 *
 709 * clk_rate_exclusive_put() completes a critical section during which a clock
 710 * consumer cannot tolerate any other consumer making any operation on the
 711 * clock which could result in a rate change or rate glitch. Exclusive clocks
 712 * cannot have their rate changed, either directly or indirectly due to changes
 713 * further up the parent chain of clocks. As a result, clocks up parent chain
 714 * also get under exclusive control of the calling consumer.
 715 *
 716 * If exlusivity is claimed more than once on clock, even by the same consumer,
 717 * the rate effectively gets locked as exclusivity can't be preempted.
 718 *
 719 * Calls to clk_rate_exclusive_put() must be balanced with calls to
 720 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
 721 * error status.
 722 */
 723void clk_rate_exclusive_put(struct clk *clk)
 724{
 725        if (!clk)
 726                return;
 727
 728        clk_prepare_lock();
 729
 730        /*
 731         * if there is something wrong with this consumer protect count, stop
 732         * here before messing with the provider
 733         */
 734        if (WARN_ON(clk->exclusive_count <= 0))
 735                goto out;
 736
 737        clk_core_rate_unprotect(clk->core);
 738        clk->exclusive_count--;
 739out:
 740        clk_prepare_unlock();
 741}
 742EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
 743
 744static void clk_core_rate_protect(struct clk_core *core)
 745{
 746        lockdep_assert_held(&prepare_lock);
 747
 748        if (!core)
 749                return;
 750
 751        if (core->protect_count == 0)
 752                clk_core_rate_protect(core->parent);
 753
 754        core->protect_count++;
 755}
 756
 757static void clk_core_rate_restore_protect(struct clk_core *core, int count)
 758{
 759        lockdep_assert_held(&prepare_lock);
 760
 761        if (!core)
 762                return;
 763
 764        if (count == 0)
 765                return;
 766
 767        clk_core_rate_protect(core);
 768        core->protect_count = count;
 769}
 770
 771/**
 772 * clk_rate_exclusive_get - get exclusivity over the clk rate control
 773 * @clk: the clk over which the exclusity of rate control is requested
 774 *
 775 * clk_rate_exclusive_get() begins a critical section during which a clock
 776 * consumer cannot tolerate any other consumer making any operation on the
 777 * clock which could result in a rate change or rate glitch. Exclusive clocks
 778 * cannot have their rate changed, either directly or indirectly due to changes
 779 * further up the parent chain of clocks. As a result, clocks up parent chain
 780 * also get under exclusive control of the calling consumer.
 781 *
 782 * If exlusivity is claimed more than once on clock, even by the same consumer,
 783 * the rate effectively gets locked as exclusivity can't be preempted.
 784 *
 785 * Calls to clk_rate_exclusive_get() should be balanced with calls to
 786 * clk_rate_exclusive_put(). Calls to this function may sleep.
 787 * Returns 0 on success, -EERROR otherwise
 788 */
 789int clk_rate_exclusive_get(struct clk *clk)
 790{
 791        if (!clk)
 792                return 0;
 793
 794        clk_prepare_lock();
 795        clk_core_rate_protect(clk->core);
 796        clk->exclusive_count++;
 797        clk_prepare_unlock();
 798
 799        return 0;
 800}
 801EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
 802
 803static void clk_core_unprepare(struct clk_core *core)
 804{
 805        lockdep_assert_held(&prepare_lock);
 806
 807        if (!core)
 808                return;
 809
 810        if (WARN(core->prepare_count == 0,
 811            "%s already unprepared\n", core->name))
 812                return;
 813
 814        if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
 815            "Unpreparing critical %s\n", core->name))
 816                return;
 817
 818        if (core->flags & CLK_SET_RATE_GATE)
 819                clk_core_rate_unprotect(core);
 820
 821        if (--core->prepare_count > 0)
 822                return;
 823
 824        WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
 825
 826        trace_clk_unprepare(core);
 827
 828        if (core->ops->unprepare)
 829                core->ops->unprepare(core->hw);
 830
 831        clk_pm_runtime_put(core);
 832
 833        trace_clk_unprepare_complete(core);
 834        clk_core_unprepare(core->parent);
 835}
 836
 837static void clk_core_unprepare_lock(struct clk_core *core)
 838{
 839        clk_prepare_lock();
 840        clk_core_unprepare(core);
 841        clk_prepare_unlock();
 842}
 843
 844/**
 845 * clk_unprepare - undo preparation of a clock source
 846 * @clk: the clk being unprepared
 847 *
 848 * clk_unprepare may sleep, which differentiates it from clk_disable.  In a
 849 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
 850 * if the operation may sleep.  One example is a clk which is accessed over
 851 * I2c.  In the complex case a clk gate operation may require a fast and a slow
 852 * part.  It is this reason that clk_unprepare and clk_disable are not mutually
 853 * exclusive.  In fact clk_disable must be called before clk_unprepare.
 854 */
 855void clk_unprepare(struct clk *clk)
 856{
 857        if (IS_ERR_OR_NULL(clk))
 858                return;
 859
 860        clk_core_unprepare_lock(clk->core);
 861}
 862EXPORT_SYMBOL_GPL(clk_unprepare);
 863
 864static int clk_core_prepare(struct clk_core *core)
 865{
 866        int ret = 0;
 867
 868        lockdep_assert_held(&prepare_lock);
 869
 870        if (!core)
 871                return 0;
 872
 873        if (core->prepare_count == 0) {
 874                ret = clk_pm_runtime_get(core);
 875                if (ret)
 876                        return ret;
 877
 878                ret = clk_core_prepare(core->parent);
 879                if (ret)
 880                        goto runtime_put;
 881
 882                trace_clk_prepare(core);
 883
 884                if (core->ops->prepare)
 885                        ret = core->ops->prepare(core->hw);
 886
 887                trace_clk_prepare_complete(core);
 888
 889                if (ret)
 890                        goto unprepare;
 891        }
 892
 893        core->prepare_count++;
 894
 895        /*
 896         * CLK_SET_RATE_GATE is a special case of clock protection
 897         * Instead of a consumer claiming exclusive rate control, it is
 898         * actually the provider which prevents any consumer from making any
 899         * operation which could result in a rate change or rate glitch while
 900         * the clock is prepared.
 901         */
 902        if (core->flags & CLK_SET_RATE_GATE)
 903                clk_core_rate_protect(core);
 904
 905        return 0;
 906unprepare:
 907        clk_core_unprepare(core->parent);
 908runtime_put:
 909        clk_pm_runtime_put(core);
 910        return ret;
 911}
 912
 913static int clk_core_prepare_lock(struct clk_core *core)
 914{
 915        int ret;
 916
 917        clk_prepare_lock();
 918        ret = clk_core_prepare(core);
 919        clk_prepare_unlock();
 920
 921        return ret;
 922}
 923
 924/**
 925 * clk_prepare - prepare a clock source
 926 * @clk: the clk being prepared
 927 *
 928 * clk_prepare may sleep, which differentiates it from clk_enable.  In a simple
 929 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
 930 * operation may sleep.  One example is a clk which is accessed over I2c.  In
 931 * the complex case a clk ungate operation may require a fast and a slow part.
 932 * It is this reason that clk_prepare and clk_enable are not mutually
 933 * exclusive.  In fact clk_prepare must be called before clk_enable.
 934 * Returns 0 on success, -EERROR otherwise.
 935 */
 936int clk_prepare(struct clk *clk)
 937{
 938        if (!clk)
 939                return 0;
 940
 941        return clk_core_prepare_lock(clk->core);
 942}
 943EXPORT_SYMBOL_GPL(clk_prepare);
 944
 945static void clk_core_disable(struct clk_core *core)
 946{
 947        lockdep_assert_held(&enable_lock);
 948
 949        if (!core)
 950                return;
 951
 952        if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
 953                return;
 954
 955        if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
 956            "Disabling critical %s\n", core->name))
 957                return;
 958
 959        if (--core->enable_count > 0)
 960                return;
 961
 962        trace_clk_disable_rcuidle(core);
 963
 964        if (core->ops->disable)
 965                core->ops->disable(core->hw);
 966
 967        trace_clk_disable_complete_rcuidle(core);
 968
 969        clk_core_disable(core->parent);
 970}
 971
 972static void clk_core_disable_lock(struct clk_core *core)
 973{
 974        unsigned long flags;
 975
 976        flags = clk_enable_lock();
 977        clk_core_disable(core);
 978        clk_enable_unlock(flags);
 979}
 980
 981/**
 982 * clk_disable - gate a clock
 983 * @clk: the clk being gated
 984 *
 985 * clk_disable must not sleep, which differentiates it from clk_unprepare.  In
 986 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
 987 * clk if the operation is fast and will never sleep.  One example is a
 988 * SoC-internal clk which is controlled via simple register writes.  In the
 989 * complex case a clk gate operation may require a fast and a slow part.  It is
 990 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
 991 * In fact clk_disable must be called before clk_unprepare.
 992 */
 993void clk_disable(struct clk *clk)
 994{
 995        if (IS_ERR_OR_NULL(clk))
 996                return;
 997
 998        clk_core_disable_lock(clk->core);
 999}
1000EXPORT_SYMBOL_GPL(clk_disable);
1001
1002static int clk_core_enable(struct clk_core *core)
1003{
1004        int ret = 0;
1005
1006        lockdep_assert_held(&enable_lock);
1007
1008        if (!core)
1009                return 0;
1010
1011        if (WARN(core->prepare_count == 0,
1012            "Enabling unprepared %s\n", core->name))
1013                return -ESHUTDOWN;
1014
1015        if (core->enable_count == 0) {
1016                ret = clk_core_enable(core->parent);
1017
1018                if (ret)
1019                        return ret;
1020
1021                trace_clk_enable_rcuidle(core);
1022
1023                if (core->ops->enable)
1024                        ret = core->ops->enable(core->hw);
1025
1026                trace_clk_enable_complete_rcuidle(core);
1027
1028                if (ret) {
1029                        clk_core_disable(core->parent);
1030                        return ret;
1031                }
1032        }
1033
1034        core->enable_count++;
1035        return 0;
1036}
1037
1038static int clk_core_enable_lock(struct clk_core *core)
1039{
1040        unsigned long flags;
1041        int ret;
1042
1043        flags = clk_enable_lock();
1044        ret = clk_core_enable(core);
1045        clk_enable_unlock(flags);
1046
1047        return ret;
1048}
1049
1050/**
1051 * clk_gate_restore_context - restore context for poweroff
1052 * @hw: the clk_hw pointer of clock whose state is to be restored
1053 *
1054 * The clock gate restore context function enables or disables
1055 * the gate clocks based on the enable_count. This is done in cases
1056 * where the clock context is lost and based on the enable_count
1057 * the clock either needs to be enabled/disabled. This
1058 * helps restore the state of gate clocks.
1059 */
1060void clk_gate_restore_context(struct clk_hw *hw)
1061{
1062        struct clk_core *core = hw->core;
1063
1064        if (core->enable_count)
1065                core->ops->enable(hw);
1066        else
1067                core->ops->disable(hw);
1068}
1069EXPORT_SYMBOL_GPL(clk_gate_restore_context);
1070
1071static int clk_core_save_context(struct clk_core *core)
1072{
1073        struct clk_core *child;
1074        int ret = 0;
1075
1076        hlist_for_each_entry(child, &core->children, child_node) {
1077                ret = clk_core_save_context(child);
1078                if (ret < 0)
1079                        return ret;
1080        }
1081
1082        if (core->ops && core->ops->save_context)
1083                ret = core->ops->save_context(core->hw);
1084
1085        return ret;
1086}
1087
1088static void clk_core_restore_context(struct clk_core *core)
1089{
1090        struct clk_core *child;
1091
1092        if (core->ops && core->ops->restore_context)
1093                core->ops->restore_context(core->hw);
1094
1095        hlist_for_each_entry(child, &core->children, child_node)
1096                clk_core_restore_context(child);
1097}
1098
1099/**
1100 * clk_save_context - save clock context for poweroff
1101 *
1102 * Saves the context of the clock register for powerstates in which the
1103 * contents of the registers will be lost. Occurs deep within the suspend
1104 * code.  Returns 0 on success.
1105 */
1106int clk_save_context(void)
1107{
1108        struct clk_core *clk;
1109        int ret;
1110
1111        hlist_for_each_entry(clk, &clk_root_list, child_node) {
1112                ret = clk_core_save_context(clk);
1113                if (ret < 0)
1114                        return ret;
1115        }
1116
1117        hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
1118                ret = clk_core_save_context(clk);
1119                if (ret < 0)
1120                        return ret;
1121        }
1122
1123        return 0;
1124}
1125EXPORT_SYMBOL_GPL(clk_save_context);
1126
1127/**
1128 * clk_restore_context - restore clock context after poweroff
1129 *
1130 * Restore the saved clock context upon resume.
1131 *
1132 */
1133void clk_restore_context(void)
1134{
1135        struct clk_core *core;
1136
1137        hlist_for_each_entry(core, &clk_root_list, child_node)
1138                clk_core_restore_context(core);
1139
1140        hlist_for_each_entry(core, &clk_orphan_list, child_node)
1141                clk_core_restore_context(core);
1142}
1143EXPORT_SYMBOL_GPL(clk_restore_context);
1144
1145/**
1146 * clk_enable - ungate a clock
1147 * @clk: the clk being ungated
1148 *
1149 * clk_enable must not sleep, which differentiates it from clk_prepare.  In a
1150 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
1151 * if the operation will never sleep.  One example is a SoC-internal clk which
1152 * is controlled via simple register writes.  In the complex case a clk ungate
1153 * operation may require a fast and a slow part.  It is this reason that
1154 * clk_enable and clk_prepare are not mutually exclusive.  In fact clk_prepare
1155 * must be called before clk_enable.  Returns 0 on success, -EERROR
1156 * otherwise.
1157 */
1158int clk_enable(struct clk *clk)
1159{
1160        if (!clk)
1161                return 0;
1162
1163        return clk_core_enable_lock(clk->core);
1164}
1165EXPORT_SYMBOL_GPL(clk_enable);
1166
1167/**
1168 * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it.
1169 * @clk: clock source
1170 *
1171 * Returns true if clk_prepare() implicitly enables the clock, effectively
1172 * making clk_enable()/clk_disable() no-ops, false otherwise.
1173 *
1174 * This is of interest mainly to power management code where actually
1175 * disabling the clock also requires unpreparing it to have any material
1176 * effect.
1177 *
1178 * Regardless of the value returned here, the caller must always invoke
1179 * clk_enable() or clk_prepare_enable()  and counterparts for usage counts
1180 * to be right.
1181 */
1182bool clk_is_enabled_when_prepared(struct clk *clk)
1183{
1184        return clk && !(clk->core->ops->enable && clk->core->ops->disable);
1185}
1186EXPORT_SYMBOL_GPL(clk_is_enabled_when_prepared);
1187
1188static int clk_core_prepare_enable(struct clk_core *core)
1189{
1190        int ret;
1191
1192        ret = clk_core_prepare_lock(core);
1193        if (ret)
1194                return ret;
1195
1196        ret = clk_core_enable_lock(core);
1197        if (ret)
1198                clk_core_unprepare_lock(core);
1199
1200        return ret;
1201}
1202
1203static void clk_core_disable_unprepare(struct clk_core *core)
1204{
1205        clk_core_disable_lock(core);
1206        clk_core_unprepare_lock(core);
1207}
1208
1209static void __init clk_unprepare_unused_subtree(struct clk_core *core)
1210{
1211        struct clk_core *child;
1212
1213        lockdep_assert_held(&prepare_lock);
1214
1215        hlist_for_each_entry(child, &core->children, child_node)
1216                clk_unprepare_unused_subtree(child);
1217
1218        if (core->prepare_count)
1219                return;
1220
1221        if (core->flags & CLK_IGNORE_UNUSED)
1222                return;
1223
1224        if (clk_pm_runtime_get(core))
1225                return;
1226
1227        if (clk_core_is_prepared(core)) {
1228                trace_clk_unprepare(core);
1229                if (core->ops->unprepare_unused)
1230                        core->ops->unprepare_unused(core->hw);
1231                else if (core->ops->unprepare)
1232                        core->ops->unprepare(core->hw);
1233                trace_clk_unprepare_complete(core);
1234        }
1235
1236        clk_pm_runtime_put(core);
1237}
1238
1239static void __init clk_disable_unused_subtree(struct clk_core *core)
1240{
1241        struct clk_core *child;
1242        unsigned long flags;
1243
1244        lockdep_assert_held(&prepare_lock);
1245
1246        hlist_for_each_entry(child, &core->children, child_node)
1247                clk_disable_unused_subtree(child);
1248
1249        if (core->flags & CLK_OPS_PARENT_ENABLE)
1250                clk_core_prepare_enable(core->parent);
1251
1252        if (clk_pm_runtime_get(core))
1253                goto unprepare_out;
1254
1255        flags = clk_enable_lock();
1256
1257        if (core->enable_count)
1258                goto unlock_out;
1259
1260        if (core->flags & CLK_IGNORE_UNUSED)
1261                goto unlock_out;
1262
1263        /*
1264         * some gate clocks have special needs during the disable-unused
1265         * sequence.  call .disable_unused if available, otherwise fall
1266         * back to .disable
1267         */
1268        if (clk_core_is_enabled(core)) {
1269                trace_clk_disable(core);
1270                if (core->ops->disable_unused)
1271                        core->ops->disable_unused(core->hw);
1272                else if (core->ops->disable)
1273                        core->ops->disable(core->hw);
1274                trace_clk_disable_complete(core);
1275        }
1276
1277unlock_out:
1278        clk_enable_unlock(flags);
1279        clk_pm_runtime_put(core);
1280unprepare_out:
1281        if (core->flags & CLK_OPS_PARENT_ENABLE)
1282                clk_core_disable_unprepare(core->parent);
1283}
1284
1285static bool clk_ignore_unused __initdata;
1286static int __init clk_ignore_unused_setup(char *__unused)
1287{
1288        clk_ignore_unused = true;
1289        return 1;
1290}
1291__setup("clk_ignore_unused", clk_ignore_unused_setup);
1292
1293static int __init clk_disable_unused(void)
1294{
1295        struct clk_core *core;
1296
1297        if (clk_ignore_unused) {
1298                pr_warn("clk: Not disabling unused clocks\n");
1299                return 0;
1300        }
1301
1302        clk_prepare_lock();
1303
1304        hlist_for_each_entry(core, &clk_root_list, child_node)
1305                clk_disable_unused_subtree(core);
1306
1307        hlist_for_each_entry(core, &clk_orphan_list, child_node)
1308                clk_disable_unused_subtree(core);
1309
1310        hlist_for_each_entry(core, &clk_root_list, child_node)
1311                clk_unprepare_unused_subtree(core);
1312
1313        hlist_for_each_entry(core, &clk_orphan_list, child_node)
1314                clk_unprepare_unused_subtree(core);
1315
1316        clk_prepare_unlock();
1317
1318        return 0;
1319}
1320late_initcall_sync(clk_disable_unused);
1321
1322static int clk_core_determine_round_nolock(struct clk_core *core,
1323                                           struct clk_rate_request *req)
1324{
1325        long rate;
1326
1327        lockdep_assert_held(&prepare_lock);
1328
1329        if (!core)
1330                return 0;
1331
1332        /*
1333         * At this point, core protection will be disabled
1334         * - if the provider is not protected at all
1335         * - if the calling consumer is the only one which has exclusivity
1336         *   over the provider
1337         */
1338        if (clk_core_rate_is_protected(core)) {
1339                req->rate = core->rate;
1340        } else if (core->ops->determine_rate) {
1341                return core->ops->determine_rate(core->hw, req);
1342        } else if (core->ops->round_rate) {
1343                rate = core->ops->round_rate(core->hw, req->rate,
1344                                             &req->best_parent_rate);
1345                if (rate < 0)
1346                        return rate;
1347
1348                req->rate = rate;
1349        } else {
1350                return -EINVAL;
1351        }
1352
1353        return 0;
1354}
1355
1356static void clk_core_init_rate_req(struct clk_core * const core,
1357                                   struct clk_rate_request *req)
1358{
1359        struct clk_core *parent;
1360
1361        if (WARN_ON(!core || !req))
1362                return;
1363
1364        parent = core->parent;
1365        if (parent) {
1366                req->best_parent_hw = parent->hw;
1367                req->best_parent_rate = parent->rate;
1368        } else {
1369                req->best_parent_hw = NULL;
1370                req->best_parent_rate = 0;
1371        }
1372}
1373
1374static bool clk_core_can_round(struct clk_core * const core)
1375{
1376        return core->ops->determine_rate || core->ops->round_rate;
1377}
1378
1379static int clk_core_round_rate_nolock(struct clk_core *core,
1380                                      struct clk_rate_request *req)
1381{
1382        lockdep_assert_held(&prepare_lock);
1383
1384        if (!core) {
1385                req->rate = 0;
1386                return 0;
1387        }
1388
1389        clk_core_init_rate_req(core, req);
1390
1391        if (clk_core_can_round(core))
1392                return clk_core_determine_round_nolock(core, req);
1393        else if (core->flags & CLK_SET_RATE_PARENT)
1394                return clk_core_round_rate_nolock(core->parent, req);
1395
1396        req->rate = core->rate;
1397        return 0;
1398}
1399
1400/**
1401 * __clk_determine_rate - get the closest rate actually supported by a clock
1402 * @hw: determine the rate of this clock
1403 * @req: target rate request
1404 *
1405 * Useful for clk_ops such as .set_rate and .determine_rate.
1406 */
1407int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1408{
1409        if (!hw) {
1410                req->rate = 0;
1411                return 0;
1412        }
1413
1414        return clk_core_round_rate_nolock(hw->core, req);
1415}
1416EXPORT_SYMBOL_GPL(__clk_determine_rate);
1417
1418/**
1419 * clk_hw_round_rate() - round the given rate for a hw clk
1420 * @hw: the hw clk for which we are rounding a rate
1421 * @rate: the rate which is to be rounded
1422 *
1423 * Takes in a rate as input and rounds it to a rate that the clk can actually
1424 * use.
1425 *
1426 * Context: prepare_lock must be held.
1427 *          For clk providers to call from within clk_ops such as .round_rate,
1428 *          .determine_rate.
1429 *
1430 * Return: returns rounded rate of hw clk if clk supports round_rate operation
1431 *         else returns the parent rate.
1432 */
1433unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1434{
1435        int ret;
1436        struct clk_rate_request req;
1437
1438        clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
1439        req.rate = rate;
1440
1441        ret = clk_core_round_rate_nolock(hw->core, &req);
1442        if (ret)
1443                return 0;
1444
1445        return req.rate;
1446}
1447EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1448
1449/**
1450 * clk_round_rate - round the given rate for a clk
1451 * @clk: the clk for which we are rounding a rate
1452 * @rate: the rate which is to be rounded
1453 *
1454 * Takes in a rate as input and rounds it to a rate that the clk can actually
1455 * use which is then returned.  If clk doesn't support round_rate operation
1456 * then the parent rate is returned.
1457 */
1458long clk_round_rate(struct clk *clk, unsigned long rate)
1459{
1460        struct clk_rate_request req;
1461        int ret;
1462
1463        if (!clk)
1464                return 0;
1465
1466        clk_prepare_lock();
1467
1468        if (clk->exclusive_count)
1469                clk_core_rate_unprotect(clk->core);
1470
1471        clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
1472        req.rate = rate;
1473
1474        ret = clk_core_round_rate_nolock(clk->core, &req);
1475
1476        if (clk->exclusive_count)
1477                clk_core_rate_protect(clk->core);
1478
1479        clk_prepare_unlock();
1480
1481        if (ret)
1482                return ret;
1483
1484        return req.rate;
1485}
1486EXPORT_SYMBOL_GPL(clk_round_rate);
1487
1488/**
1489 * __clk_notify - call clk notifier chain
1490 * @core: clk that is changing rate
1491 * @msg: clk notifier type (see include/linux/clk.h)
1492 * @old_rate: old clk rate
1493 * @new_rate: new clk rate
1494 *
1495 * Triggers a notifier call chain on the clk rate-change notification
1496 * for 'clk'.  Passes a pointer to the struct clk and the previous
1497 * and current rates to the notifier callback.  Intended to be called by
1498 * internal clock code only.  Returns NOTIFY_DONE from the last driver
1499 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1500 * a driver returns that.
1501 */
1502static int __clk_notify(struct clk_core *core, unsigned long msg,
1503                unsigned long old_rate, unsigned long new_rate)
1504{
1505        struct clk_notifier *cn;
1506        struct clk_notifier_data cnd;
1507        int ret = NOTIFY_DONE;
1508
1509        cnd.old_rate = old_rate;
1510        cnd.new_rate = new_rate;
1511
1512        list_for_each_entry(cn, &clk_notifier_list, node) {
1513                if (cn->clk->core == core) {
1514                        cnd.clk = cn->clk;
1515                        ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1516                                        &cnd);
1517                        if (ret & NOTIFY_STOP_MASK)
1518                                return ret;
1519                }
1520        }
1521
1522        return ret;
1523}
1524
1525/**
1526 * __clk_recalc_accuracies
1527 * @core: first clk in the subtree
1528 *
1529 * Walks the subtree of clks starting with clk and recalculates accuracies as
1530 * it goes.  Note that if a clk does not implement the .recalc_accuracy
1531 * callback then it is assumed that the clock will take on the accuracy of its
1532 * parent.
1533 */
1534static void __clk_recalc_accuracies(struct clk_core *core)
1535{
1536        unsigned long parent_accuracy = 0;
1537        struct clk_core *child;
1538
1539        lockdep_assert_held(&prepare_lock);
1540
1541        if (core->parent)
1542                parent_accuracy = core->parent->accuracy;
1543
1544        if (core->ops->recalc_accuracy)
1545                core->accuracy = core->ops->recalc_accuracy(core->hw,
1546                                                          parent_accuracy);
1547        else
1548                core->accuracy = parent_accuracy;
1549
1550        hlist_for_each_entry(child, &core->children, child_node)
1551                __clk_recalc_accuracies(child);
1552}
1553
1554static long clk_core_get_accuracy_recalc(struct clk_core *core)
1555{
1556        if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1557                __clk_recalc_accuracies(core);
1558
1559        return clk_core_get_accuracy_no_lock(core);
1560}
1561
1562/**
1563 * clk_get_accuracy - return the accuracy of clk
1564 * @clk: the clk whose accuracy is being returned
1565 *
1566 * Simply returns the cached accuracy of the clk, unless
1567 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1568 * issued.
1569 * If clk is NULL then returns 0.
1570 */
1571long clk_get_accuracy(struct clk *clk)
1572{
1573        long accuracy;
1574
1575        if (!clk)
1576                return 0;
1577
1578        clk_prepare_lock();
1579        accuracy = clk_core_get_accuracy_recalc(clk->core);
1580        clk_prepare_unlock();
1581
1582        return accuracy;
1583}
1584EXPORT_SYMBOL_GPL(clk_get_accuracy);
1585
1586static unsigned long clk_recalc(struct clk_core *core,
1587                                unsigned long parent_rate)
1588{
1589        unsigned long rate = parent_rate;
1590
1591        if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1592                rate = core->ops->recalc_rate(core->hw, parent_rate);
1593                clk_pm_runtime_put(core);
1594        }
1595        return rate;
1596}
1597
1598/**
1599 * __clk_recalc_rates
1600 * @core: first clk in the subtree
1601 * @msg: notification type (see include/linux/clk.h)
1602 *
1603 * Walks the subtree of clks starting with clk and recalculates rates as it
1604 * goes.  Note that if a clk does not implement the .recalc_rate callback then
1605 * it is assumed that the clock will take on the rate of its parent.
1606 *
1607 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1608 * if necessary.
1609 */
1610static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
1611{
1612        unsigned long old_rate;
1613        unsigned long parent_rate = 0;
1614        struct clk_core *child;
1615
1616        lockdep_assert_held(&prepare_lock);
1617
1618        old_rate = core->rate;
1619
1620        if (core->parent)
1621                parent_rate = core->parent->rate;
1622
1623        core->rate = clk_recalc(core, parent_rate);
1624
1625        /*
1626         * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1627         * & ABORT_RATE_CHANGE notifiers
1628         */
1629        if (core->notifier_count && msg)
1630                __clk_notify(core, msg, old_rate, core->rate);
1631
1632        hlist_for_each_entry(child, &core->children, child_node)
1633                __clk_recalc_rates(child, msg);
1634}
1635
1636static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
1637{
1638        if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1639                __clk_recalc_rates(core, 0);
1640
1641        return clk_core_get_rate_nolock(core);
1642}
1643
1644/**
1645 * clk_get_rate - return the rate of clk
1646 * @clk: the clk whose rate is being returned
1647 *
1648 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1649 * is set, which means a recalc_rate will be issued.
1650 * If clk is NULL then returns 0.
1651 */
1652unsigned long clk_get_rate(struct clk *clk)
1653{
1654        unsigned long rate;
1655
1656        if (!clk)
1657                return 0;
1658
1659        clk_prepare_lock();
1660        rate = clk_core_get_rate_recalc(clk->core);
1661        clk_prepare_unlock();
1662
1663        return rate;
1664}
1665EXPORT_SYMBOL_GPL(clk_get_rate);
1666
1667static int clk_fetch_parent_index(struct clk_core *core,
1668                                  struct clk_core *parent)
1669{
1670        int i;
1671
1672        if (!parent)
1673                return -EINVAL;
1674
1675        for (i = 0; i < core->num_parents; i++) {
1676                /* Found it first try! */
1677                if (core->parents[i].core == parent)
1678                        return i;
1679
1680                /* Something else is here, so keep looking */
1681                if (core->parents[i].core)
1682                        continue;
1683
1684                /* Maybe core hasn't been cached but the hw is all we know? */
1685                if (core->parents[i].hw) {
1686                        if (core->parents[i].hw == parent->hw)
1687                                break;
1688
1689                        /* Didn't match, but we're expecting a clk_hw */
1690                        continue;
1691                }
1692
1693                /* Maybe it hasn't been cached (clk_set_parent() path) */
1694                if (parent == clk_core_get(core, i))
1695                        break;
1696
1697                /* Fallback to comparing globally unique names */
1698                if (core->parents[i].name &&
1699                    !strcmp(parent->name, core->parents[i].name))
1700                        break;
1701        }
1702
1703        if (i == core->num_parents)
1704                return -EINVAL;
1705
1706        core->parents[i].core = parent;
1707        return i;
1708}
1709
1710/**
1711 * clk_hw_get_parent_index - return the index of the parent clock
1712 * @hw: clk_hw associated with the clk being consumed
1713 *
1714 * Fetches and returns the index of parent clock. Returns -EINVAL if the given
1715 * clock does not have a current parent.
1716 */
1717int clk_hw_get_parent_index(struct clk_hw *hw)
1718{
1719        struct clk_hw *parent = clk_hw_get_parent(hw);
1720
1721        if (WARN_ON(parent == NULL))
1722                return -EINVAL;
1723
1724        return clk_fetch_parent_index(hw->core, parent->core);
1725}
1726EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);
1727
1728/*
1729 * Update the orphan status of @core and all its children.
1730 */
1731static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1732{
1733        struct clk_core *child;
1734
1735        core->orphan = is_orphan;
1736
1737        hlist_for_each_entry(child, &core->children, child_node)
1738                clk_core_update_orphan_status(child, is_orphan);
1739}
1740
1741static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1742{
1743        bool was_orphan = core->orphan;
1744
1745        hlist_del(&core->child_node);
1746
1747        if (new_parent) {
1748                bool becomes_orphan = new_parent->orphan;
1749
1750                /* avoid duplicate POST_RATE_CHANGE notifications */
1751                if (new_parent->new_child == core)
1752                        new_parent->new_child = NULL;
1753
1754                hlist_add_head(&core->child_node, &new_parent->children);
1755
1756                if (was_orphan != becomes_orphan)
1757                        clk_core_update_orphan_status(core, becomes_orphan);
1758        } else {
1759                hlist_add_head(&core->child_node, &clk_orphan_list);
1760                if (!was_orphan)
1761                        clk_core_update_orphan_status(core, true);
1762        }
1763
1764        core->parent = new_parent;
1765}
1766
1767static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1768                                           struct clk_core *parent)
1769{
1770        unsigned long flags;
1771        struct clk_core *old_parent = core->parent;
1772
1773        /*
1774         * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1775         *
1776         * 2. Migrate prepare state between parents and prevent race with
1777         * clk_enable().
1778         *
1779         * If the clock is not prepared, then a race with
1780         * clk_enable/disable() is impossible since we already have the
1781         * prepare lock (future calls to clk_enable() need to be preceded by
1782         * a clk_prepare()).
1783         *
1784         * If the clock is prepared, migrate the prepared state to the new
1785         * parent and also protect against a race with clk_enable() by
1786         * forcing the clock and the new parent on.  This ensures that all
1787         * future calls to clk_enable() are practically NOPs with respect to
1788         * hardware and software states.
1789         *
1790         * See also: Comment for clk_set_parent() below.
1791         */
1792
1793        /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1794        if (core->flags & CLK_OPS_PARENT_ENABLE) {
1795                clk_core_prepare_enable(old_parent);
1796                clk_core_prepare_enable(parent);
1797        }
1798
1799        /* migrate prepare count if > 0 */
1800        if (core->prepare_count) {
1801                clk_core_prepare_enable(parent);
1802                clk_core_enable_lock(core);
1803        }
1804
1805        /* update the clk tree topology */
1806        flags = clk_enable_lock();
1807        clk_reparent(core, parent);
1808        clk_enable_unlock(flags);
1809
1810        return old_parent;
1811}
1812
1813static void __clk_set_parent_after(struct clk_core *core,
1814                                   struct clk_core *parent,
1815                                   struct clk_core *old_parent)
1816{
1817        /*
1818         * Finish the migration of prepare state and undo the changes done
1819         * for preventing a race with clk_enable().
1820         */
1821        if (core->prepare_count) {
1822                clk_core_disable_lock(core);
1823                clk_core_disable_unprepare(old_parent);
1824        }
1825
1826        /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1827        if (core->flags & CLK_OPS_PARENT_ENABLE) {
1828                clk_core_disable_unprepare(parent);
1829                clk_core_disable_unprepare(old_parent);
1830        }
1831}
1832
1833static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1834                            u8 p_index)
1835{
1836        unsigned long flags;
1837        int ret = 0;
1838        struct clk_core *old_parent;
1839
1840        old_parent = __clk_set_parent_before(core, parent);
1841
1842        trace_clk_set_parent(core, parent);
1843
1844        /* change clock input source */
1845        if (parent && core->ops->set_parent)
1846                ret = core->ops->set_parent(core->hw, p_index);
1847
1848        trace_clk_set_parent_complete(core, parent);
1849
1850        if (ret) {
1851                flags = clk_enable_lock();
1852                clk_reparent(core, old_parent);
1853                clk_enable_unlock(flags);
1854                __clk_set_parent_after(core, old_parent, parent);
1855
1856                return ret;
1857        }
1858
1859        __clk_set_parent_after(core, parent, old_parent);
1860
1861        return 0;
1862}
1863
1864/**
1865 * __clk_speculate_rates
1866 * @core: first clk in the subtree
1867 * @parent_rate: the "future" rate of clk's parent
1868 *
1869 * Walks the subtree of clks starting with clk, speculating rates as it
1870 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1871 *
1872 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1873 * pre-rate change notifications and returns early if no clks in the
1874 * subtree have subscribed to the notifications.  Note that if a clk does not
1875 * implement the .recalc_rate callback then it is assumed that the clock will
1876 * take on the rate of its parent.
1877 */
1878static int __clk_speculate_rates(struct clk_core *core,
1879                                 unsigned long parent_rate)
1880{
1881        struct clk_core *child;
1882        unsigned long new_rate;
1883        int ret = NOTIFY_DONE;
1884
1885        lockdep_assert_held(&prepare_lock);
1886
1887        new_rate = clk_recalc(core, parent_rate);
1888
1889        /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1890        if (core->notifier_count)
1891                ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1892
1893        if (ret & NOTIFY_STOP_MASK) {
1894                pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1895                                __func__, core->name, ret);
1896                goto out;
1897        }
1898
1899        hlist_for_each_entry(child, &core->children, child_node) {
1900                ret = __clk_speculate_rates(child, new_rate);
1901                if (ret & NOTIFY_STOP_MASK)
1902                        break;
1903        }
1904
1905out:
1906        return ret;
1907}
1908
1909static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1910                             struct clk_core *new_parent, u8 p_index)
1911{
1912        struct clk_core *child;
1913
1914        core->new_rate = new_rate;
1915        core->new_parent = new_parent;
1916        core->new_parent_index = p_index;
1917        /* include clk in new parent's PRE_RATE_CHANGE notifications */
1918        core->new_child = NULL;
1919        if (new_parent && new_parent != core->parent)
1920                new_parent->new_child = core;
1921
1922        hlist_for_each_entry(child, &core->children, child_node) {
1923                child->new_rate = clk_recalc(child, new_rate);
1924                clk_calc_subtree(child, child->new_rate, NULL, 0);
1925        }
1926}
1927
1928/*
1929 * calculate the new rates returning the topmost clock that has to be
1930 * changed.
1931 */
1932static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1933                                           unsigned long rate)
1934{
1935        struct clk_core *top = core;
1936        struct clk_core *old_parent, *parent;
1937        unsigned long best_parent_rate = 0;
1938        unsigned long new_rate;
1939        unsigned long min_rate;
1940        unsigned long max_rate;
1941        int p_index = 0;
1942        long ret;
1943
1944        /* sanity */
1945        if (IS_ERR_OR_NULL(core))
1946                return NULL;
1947
1948        /* save parent rate, if it exists */
1949        parent = old_parent = core->parent;
1950        if (parent)
1951                best_parent_rate = parent->rate;
1952
1953        clk_core_get_boundaries(core, &min_rate, &max_rate);
1954
1955        /* find the closest rate and parent clk/rate */
1956        if (clk_core_can_round(core)) {
1957                struct clk_rate_request req;
1958
1959                req.rate = rate;
1960                req.min_rate = min_rate;
1961                req.max_rate = max_rate;
1962
1963                clk_core_init_rate_req(core, &req);
1964
1965                ret = clk_core_determine_round_nolock(core, &req);
1966                if (ret < 0)
1967                        return NULL;
1968
1969                best_parent_rate = req.best_parent_rate;
1970                new_rate = req.rate;
1971                parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1972
1973                if (new_rate < min_rate || new_rate > max_rate)
1974                        return NULL;
1975        } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1976                /* pass-through clock without adjustable parent */
1977                core->new_rate = core->rate;
1978                return NULL;
1979        } else {
1980                /* pass-through clock with adjustable parent */
1981                top = clk_calc_new_rates(parent, rate);
1982                new_rate = parent->new_rate;
1983                goto out;
1984        }
1985
1986        /* some clocks must be gated to change parent */
1987        if (parent != old_parent &&
1988            (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1989                pr_debug("%s: %s not gated but wants to reparent\n",
1990                         __func__, core->name);
1991                return NULL;
1992        }
1993
1994        /* try finding the new parent index */
1995        if (parent && core->num_parents > 1) {
1996                p_index = clk_fetch_parent_index(core, parent);
1997                if (p_index < 0) {
1998                        pr_debug("%s: clk %s can not be parent of clk %s\n",
1999                                 __func__, parent->name, core->name);
2000                        return NULL;
2001                }
2002        }
2003
2004        if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
2005            best_parent_rate != parent->rate)
2006                top = clk_calc_new_rates(parent, best_parent_rate);
2007
2008out:
2009        clk_calc_subtree(core, new_rate, parent, p_index);
2010
2011        return top;
2012}
2013
2014/*
2015 * Notify about rate changes in a subtree. Always walk down the whole tree
2016 * so that in case of an error we can walk down the whole tree again and
2017 * abort the change.
2018 */
2019static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
2020                                                  unsigned long event)
2021{
2022        struct clk_core *child, *tmp_clk, *fail_clk = NULL;
2023        int ret = NOTIFY_DONE;
2024
2025        if (core->rate == core->new_rate)
2026                return NULL;
2027
2028        if (core->notifier_count) {
2029                ret = __clk_notify(core, event, core->rate, core->new_rate);
2030                if (ret & NOTIFY_STOP_MASK)
2031                        fail_clk = core;
2032        }
2033
2034        hlist_for_each_entry(child, &core->children, child_node) {
2035                /* Skip children who will be reparented to another clock */
2036                if (child->new_parent && child->new_parent != core)
2037                        continue;
2038                tmp_clk = clk_propagate_rate_change(child, event);
2039                if (tmp_clk)
2040                        fail_clk = tmp_clk;
2041        }
2042
2043        /* handle the new child who might not be in core->children yet */
2044        if (core->new_child) {
2045                tmp_clk = clk_propagate_rate_change(core->new_child, event);
2046                if (tmp_clk)
2047                        fail_clk = tmp_clk;
2048        }
2049
2050        return fail_clk;
2051}
2052
2053/*
2054 * walk down a subtree and set the new rates notifying the rate
2055 * change on the way
2056 */
2057static void clk_change_rate(struct clk_core *core)
2058{
2059        struct clk_core *child;
2060        struct hlist_node *tmp;
2061        unsigned long old_rate;
2062        unsigned long best_parent_rate = 0;
2063        bool skip_set_rate = false;
2064        struct clk_core *old_parent;
2065        struct clk_core *parent = NULL;
2066
2067        old_rate = core->rate;
2068
2069        if (core->new_parent) {
2070                parent = core->new_parent;
2071                best_parent_rate = core->new_parent->rate;
2072        } else if (core->parent) {
2073                parent = core->parent;
2074                best_parent_rate = core->parent->rate;
2075        }
2076
2077        if (clk_pm_runtime_get(core))
2078                return;
2079
2080        if (core->flags & CLK_SET_RATE_UNGATE) {
2081                clk_core_prepare(core);
2082                clk_core_enable_lock(core);
2083        }
2084
2085        if (core->new_parent && core->new_parent != core->parent) {
2086                old_parent = __clk_set_parent_before(core, core->new_parent);
2087                trace_clk_set_parent(core, core->new_parent);
2088
2089                if (core->ops->set_rate_and_parent) {
2090                        skip_set_rate = true;
2091                        core->ops->set_rate_and_parent(core->hw, core->new_rate,
2092                                        best_parent_rate,
2093                                        core->new_parent_index);
2094                } else if (core->ops->set_parent) {
2095                        core->ops->set_parent(core->hw, core->new_parent_index);
2096                }
2097
2098                trace_clk_set_parent_complete(core, core->new_parent);
2099                __clk_set_parent_after(core, core->new_parent, old_parent);
2100        }
2101
2102        if (core->flags & CLK_OPS_PARENT_ENABLE)
2103                clk_core_prepare_enable(parent);
2104
2105        trace_clk_set_rate(core, core->new_rate);
2106
2107        if (!skip_set_rate && core->ops->set_rate)
2108                core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
2109
2110        trace_clk_set_rate_complete(core, core->new_rate);
2111
2112        core->rate = clk_recalc(core, best_parent_rate);
2113
2114        if (core->flags & CLK_SET_RATE_UNGATE) {
2115                clk_core_disable_lock(core);
2116                clk_core_unprepare(core);
2117        }
2118
2119        if (core->flags & CLK_OPS_PARENT_ENABLE)
2120                clk_core_disable_unprepare(parent);
2121
2122        if (core->notifier_count && old_rate != core->rate)
2123                __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
2124
2125        if (core->flags & CLK_RECALC_NEW_RATES)
2126                (void)clk_calc_new_rates(core, core->new_rate);
2127
2128        /*
2129         * Use safe iteration, as change_rate can actually swap parents
2130         * for certain clock types.
2131         */
2132        hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
2133                /* Skip children who will be reparented to another clock */
2134                if (child->new_parent && child->new_parent != core)
2135                        continue;
2136                clk_change_rate(child);
2137        }
2138
2139        /* handle the new child who might not be in core->children yet */
2140        if (core->new_child)
2141                clk_change_rate(core->new_child);
2142
2143        clk_pm_runtime_put(core);
2144}
2145
2146static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
2147                                                     unsigned long req_rate)
2148{
2149        int ret, cnt;
2150        struct clk_rate_request req;
2151
2152        lockdep_assert_held(&prepare_lock);
2153
2154        if (!core)
2155                return 0;
2156
2157        /* simulate what the rate would be if it could be freely set */
2158        cnt = clk_core_rate_nuke_protect(core);
2159        if (cnt < 0)
2160                return cnt;
2161
2162        clk_core_get_boundaries(core, &req.min_rate, &req.max_rate);
2163        req.rate = req_rate;
2164
2165        ret = clk_core_round_rate_nolock(core, &req);
2166
2167        /* restore the protection */
2168        clk_core_rate_restore_protect(core, cnt);
2169
2170        return ret ? 0 : req.rate;
2171}
2172
2173static int clk_core_set_rate_nolock(struct clk_core *core,
2174                                    unsigned long req_rate)
2175{
2176        struct clk_core *top, *fail_clk;
2177        unsigned long rate;
2178        int ret = 0;
2179
2180        if (!core)
2181                return 0;
2182
2183        rate = clk_core_req_round_rate_nolock(core, req_rate);
2184
2185        /* bail early if nothing to do */
2186        if (rate == clk_core_get_rate_nolock(core))
2187                return 0;
2188
2189        /* fail on a direct rate set of a protected provider */
2190        if (clk_core_rate_is_protected(core))
2191                return -EBUSY;
2192
2193        /* calculate new rates and get the topmost changed clock */
2194        top = clk_calc_new_rates(core, req_rate);
2195        if (!top)
2196                return -EINVAL;
2197
2198        ret = clk_pm_runtime_get(core);
2199        if (ret)
2200                return ret;
2201
2202        /* notify that we are about to change rates */
2203        fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
2204        if (fail_clk) {
2205                pr_debug("%s: failed to set %s rate\n", __func__,
2206                                fail_clk->name);
2207                clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
2208                ret = -EBUSY;
2209                goto err;
2210        }
2211
2212        /* change the rates */
2213        clk_change_rate(top);
2214
2215        core->req_rate = req_rate;
2216err:
2217        clk_pm_runtime_put(core);
2218
2219        return ret;
2220}
2221
2222/**
2223 * clk_set_rate - specify a new rate for clk
2224 * @clk: the clk whose rate is being changed
2225 * @rate: the new rate for clk
2226 *
2227 * In the simplest case clk_set_rate will only adjust the rate of clk.
2228 *
2229 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
2230 * propagate up to clk's parent; whether or not this happens depends on the
2231 * outcome of clk's .round_rate implementation.  If *parent_rate is unchanged
2232 * after calling .round_rate then upstream parent propagation is ignored.  If
2233 * *parent_rate comes back with a new rate for clk's parent then we propagate
2234 * up to clk's parent and set its rate.  Upward propagation will continue
2235 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
2236 * .round_rate stops requesting changes to clk's parent_rate.
2237 *
2238 * Rate changes are accomplished via tree traversal that also recalculates the
2239 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
2240 *
2241 * Returns 0 on success, -EERROR otherwise.
2242 */
2243int clk_set_rate(struct clk *clk, unsigned long rate)
2244{
2245        int ret;
2246
2247        if (!clk)
2248                return 0;
2249
2250        /* prevent racing with updates to the clock topology */
2251        clk_prepare_lock();
2252
2253        if (clk->exclusive_count)
2254                clk_core_rate_unprotect(clk->core);
2255
2256        ret = clk_core_set_rate_nolock(clk->core, rate);
2257
2258        if (clk->exclusive_count)
2259                clk_core_rate_protect(clk->core);
2260
2261        clk_prepare_unlock();
2262
2263        return ret;
2264}
2265EXPORT_SYMBOL_GPL(clk_set_rate);
2266
2267/**
2268 * clk_set_rate_exclusive - specify a new rate and get exclusive control
2269 * @clk: the clk whose rate is being changed
2270 * @rate: the new rate for clk
2271 *
2272 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2273 * within a critical section
2274 *
2275 * This can be used initially to ensure that at least 1 consumer is
2276 * satisfied when several consumers are competing for exclusivity over the
2277 * same clock provider.
2278 *
2279 * The exclusivity is not applied if setting the rate failed.
2280 *
2281 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2282 * clk_rate_exclusive_put().
2283 *
2284 * Returns 0 on success, -EERROR otherwise.
2285 */
2286int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
2287{
2288        int ret;
2289
2290        if (!clk)
2291                return 0;
2292
2293        /* prevent racing with updates to the clock topology */
2294        clk_prepare_lock();
2295
2296        /*
2297         * The temporary protection removal is not here, on purpose
2298         * This function is meant to be used instead of clk_rate_protect,
2299         * so before the consumer code path protect the clock provider
2300         */
2301
2302        ret = clk_core_set_rate_nolock(clk->core, rate);
2303        if (!ret) {
2304                clk_core_rate_protect(clk->core);
2305                clk->exclusive_count++;
2306        }
2307
2308        clk_prepare_unlock();
2309
2310        return ret;
2311}
2312EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2313
2314/**
2315 * clk_set_rate_range - set a rate range for a clock source
2316 * @clk: clock source
2317 * @min: desired minimum clock rate in Hz, inclusive
2318 * @max: desired maximum clock rate in Hz, inclusive
2319 *
2320 * Returns success (0) or negative errno.
2321 */
2322int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2323{
2324        int ret = 0;
2325        unsigned long old_min, old_max, rate;
2326
2327        if (!clk)
2328                return 0;
2329
2330        trace_clk_set_rate_range(clk->core, min, max);
2331
2332        if (min > max) {
2333                pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2334                       __func__, clk->core->name, clk->dev_id, clk->con_id,
2335                       min, max);
2336                return -EINVAL;
2337        }
2338
2339        clk_prepare_lock();
2340
2341        if (clk->exclusive_count)
2342                clk_core_rate_unprotect(clk->core);
2343
2344        /* Save the current values in case we need to rollback the change */
2345        old_min = clk->min_rate;
2346        old_max = clk->max_rate;
2347        clk->min_rate = min;
2348        clk->max_rate = max;
2349
2350        rate = clk_core_get_rate_nolock(clk->core);
2351        if (rate < min || rate > max) {
2352                /*
2353                 * FIXME:
2354                 * We are in bit of trouble here, current rate is outside the
2355                 * the requested range. We are going try to request appropriate
2356                 * range boundary but there is a catch. It may fail for the
2357                 * usual reason (clock broken, clock protected, etc) but also
2358                 * because:
2359                 * - round_rate() was not favorable and fell on the wrong
2360                 *   side of the boundary
2361                 * - the determine_rate() callback does not really check for
2362                 *   this corner case when determining the rate
2363                 */
2364
2365                if (rate < min)
2366                        rate = min;
2367                else
2368                        rate = max;
2369
2370                ret = clk_core_set_rate_nolock(clk->core, rate);
2371                if (ret) {
2372                        /* rollback the changes */
2373                        clk->min_rate = old_min;
2374                        clk->max_rate = old_max;
2375                }
2376        }
2377
2378        if (clk->exclusive_count)
2379                clk_core_rate_protect(clk->core);
2380
2381        clk_prepare_unlock();
2382
2383        return ret;
2384}
2385EXPORT_SYMBOL_GPL(clk_set_rate_range);
2386
2387/**
2388 * clk_set_min_rate - set a minimum clock rate for a clock source
2389 * @clk: clock source
2390 * @rate: desired minimum clock rate in Hz, inclusive
2391 *
2392 * Returns success (0) or negative errno.
2393 */
2394int clk_set_min_rate(struct clk *clk, unsigned long rate)
2395{
2396        if (!clk)
2397                return 0;
2398
2399        trace_clk_set_min_rate(clk->core, rate);
2400
2401        return clk_set_rate_range(clk, rate, clk->max_rate);
2402}
2403EXPORT_SYMBOL_GPL(clk_set_min_rate);
2404
2405/**
2406 * clk_set_max_rate - set a maximum clock rate for a clock source
2407 * @clk: clock source
2408 * @rate: desired maximum clock rate in Hz, inclusive
2409 *
2410 * Returns success (0) or negative errno.
2411 */
2412int clk_set_max_rate(struct clk *clk, unsigned long rate)
2413{
2414        if (!clk)
2415                return 0;
2416
2417        trace_clk_set_max_rate(clk->core, rate);
2418
2419        return clk_set_rate_range(clk, clk->min_rate, rate);
2420}
2421EXPORT_SYMBOL_GPL(clk_set_max_rate);
2422
2423/**
2424 * clk_get_parent - return the parent of a clk
2425 * @clk: the clk whose parent gets returned
2426 *
2427 * Simply returns clk->parent.  Returns NULL if clk is NULL.
2428 */
2429struct clk *clk_get_parent(struct clk *clk)
2430{
2431        struct clk *parent;
2432
2433        if (!clk)
2434                return NULL;
2435
2436        clk_prepare_lock();
2437        /* TODO: Create a per-user clk and change callers to call clk_put */
2438        parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2439        clk_prepare_unlock();
2440
2441        return parent;
2442}
2443EXPORT_SYMBOL_GPL(clk_get_parent);
2444
2445static struct clk_core *__clk_init_parent(struct clk_core *core)
2446{
2447        u8 index = 0;
2448
2449        if (core->num_parents > 1 && core->ops->get_parent)
2450                index = core->ops->get_parent(core->hw);
2451
2452        return clk_core_get_parent_by_index(core, index);
2453}
2454
2455static void clk_core_reparent(struct clk_core *core,
2456                                  struct clk_core *new_parent)
2457{
2458        clk_reparent(core, new_parent);
2459        __clk_recalc_accuracies(core);
2460        __clk_recalc_rates(core, POST_RATE_CHANGE);
2461}
2462
2463void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2464{
2465        if (!hw)
2466                return;
2467
2468        clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2469}
2470
2471/**
2472 * clk_has_parent - check if a clock is a possible parent for another
2473 * @clk: clock source
2474 * @parent: parent clock source
2475 *
2476 * This function can be used in drivers that need to check that a clock can be
2477 * the parent of another without actually changing the parent.
2478 *
2479 * Returns true if @parent is a possible parent for @clk, false otherwise.
2480 */
2481bool clk_has_parent(struct clk *clk, struct clk *parent)
2482{
2483        struct clk_core *core, *parent_core;
2484        int i;
2485
2486        /* NULL clocks should be nops, so return success if either is NULL. */
2487        if (!clk || !parent)
2488                return true;
2489
2490        core = clk->core;
2491        parent_core = parent->core;
2492
2493        /* Optimize for the case where the parent is already the parent. */
2494        if (core->parent == parent_core)
2495                return true;
2496
2497        for (i = 0; i < core->num_parents; i++)
2498                if (!strcmp(core->parents[i].name, parent_core->name))
2499                        return true;
2500
2501        return false;
2502}
2503EXPORT_SYMBOL_GPL(clk_has_parent);
2504
2505static int clk_core_set_parent_nolock(struct clk_core *core,
2506                                      struct clk_core *parent)
2507{
2508        int ret = 0;
2509        int p_index = 0;
2510        unsigned long p_rate = 0;
2511
2512        lockdep_assert_held(&prepare_lock);
2513
2514        if (!core)
2515                return 0;
2516
2517        if (core->parent == parent)
2518                return 0;
2519
2520        /* verify ops for multi-parent clks */
2521        if (core->num_parents > 1 && !core->ops->set_parent)
2522                return -EPERM;
2523
2524        /* check that we are allowed to re-parent if the clock is in use */
2525        if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2526                return -EBUSY;
2527
2528        if (clk_core_rate_is_protected(core))
2529                return -EBUSY;
2530
2531        /* try finding the new parent index */
2532        if (parent) {
2533                p_index = clk_fetch_parent_index(core, parent);
2534                if (p_index < 0) {
2535                        pr_debug("%s: clk %s can not be parent of clk %s\n",
2536                                        __func__, parent->name, core->name);
2537                        return p_index;
2538                }
2539                p_rate = parent->rate;
2540        }
2541
2542        ret = clk_pm_runtime_get(core);
2543        if (ret)
2544                return ret;
2545
2546        /* propagate PRE_RATE_CHANGE notifications */
2547        ret = __clk_speculate_rates(core, p_rate);
2548
2549        /* abort if a driver objects */
2550        if (ret & NOTIFY_STOP_MASK)
2551                goto runtime_put;
2552
2553        /* do the re-parent */
2554        ret = __clk_set_parent(core, parent, p_index);
2555
2556        /* propagate rate an accuracy recalculation accordingly */
2557        if (ret) {
2558                __clk_recalc_rates(core, ABORT_RATE_CHANGE);
2559        } else {
2560                __clk_recalc_rates(core, POST_RATE_CHANGE);
2561                __clk_recalc_accuracies(core);
2562        }
2563
2564runtime_put:
2565        clk_pm_runtime_put(core);
2566
2567        return ret;
2568}
2569
2570int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
2571{
2572        return clk_core_set_parent_nolock(hw->core, parent->core);
2573}
2574EXPORT_SYMBOL_GPL(clk_hw_set_parent);
2575
2576/**
2577 * clk_set_parent - switch the parent of a mux clk
2578 * @clk: the mux clk whose input we are switching
2579 * @parent: the new input to clk
2580 *
2581 * Re-parent clk to use parent as its new input source.  If clk is in
2582 * prepared state, the clk will get enabled for the duration of this call. If
2583 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2584 * that, the reparenting is glitchy in hardware, etc), use the
2585 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2586 *
2587 * After successfully changing clk's parent clk_set_parent will update the
2588 * clk topology, sysfs topology and propagate rate recalculation via
2589 * __clk_recalc_rates.
2590 *
2591 * Returns 0 on success, -EERROR otherwise.
2592 */
2593int clk_set_parent(struct clk *clk, struct clk *parent)
2594{
2595        int ret;
2596
2597        if (!clk)
2598                return 0;
2599
2600        clk_prepare_lock();
2601
2602        if (clk->exclusive_count)
2603                clk_core_rate_unprotect(clk->core);
2604
2605        ret = clk_core_set_parent_nolock(clk->core,
2606                                         parent ? parent->core : NULL);
2607
2608        if (clk->exclusive_count)
2609                clk_core_rate_protect(clk->core);
2610
2611        clk_prepare_unlock();
2612
2613        return ret;
2614}
2615EXPORT_SYMBOL_GPL(clk_set_parent);
2616
2617static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2618{
2619        int ret = -EINVAL;
2620
2621        lockdep_assert_held(&prepare_lock);
2622
2623        if (!core)
2624                return 0;
2625
2626        if (clk_core_rate_is_protected(core))
2627                return -EBUSY;
2628
2629        trace_clk_set_phase(core, degrees);
2630
2631        if (core->ops->set_phase) {
2632                ret = core->ops->set_phase(core->hw, degrees);
2633                if (!ret)
2634                        core->phase = degrees;
2635        }
2636
2637        trace_clk_set_phase_complete(core, degrees);
2638
2639        return ret;
2640}
2641
2642/**
2643 * clk_set_phase - adjust the phase shift of a clock signal
2644 * @clk: clock signal source
2645 * @degrees: number of degrees the signal is shifted
2646 *
2647 * Shifts the phase of a clock signal by the specified
2648 * degrees. Returns 0 on success, -EERROR otherwise.
2649 *
2650 * This function makes no distinction about the input or reference
2651 * signal that we adjust the clock signal phase against. For example
2652 * phase locked-loop clock signal generators we may shift phase with
2653 * respect to feedback clock signal input, but for other cases the
2654 * clock phase may be shifted with respect to some other, unspecified
2655 * signal.
2656 *
2657 * Additionally the concept of phase shift does not propagate through
2658 * the clock tree hierarchy, which sets it apart from clock rates and
2659 * clock accuracy. A parent clock phase attribute does not have an
2660 * impact on the phase attribute of a child clock.
2661 */
2662int clk_set_phase(struct clk *clk, int degrees)
2663{
2664        int ret;
2665
2666        if (!clk)
2667                return 0;
2668
2669        /* sanity check degrees */
2670        degrees %= 360;
2671        if (degrees < 0)
2672                degrees += 360;
2673
2674        clk_prepare_lock();
2675
2676        if (clk->exclusive_count)
2677                clk_core_rate_unprotect(clk->core);
2678
2679        ret = clk_core_set_phase_nolock(clk->core, degrees);
2680
2681        if (clk->exclusive_count)
2682                clk_core_rate_protect(clk->core);
2683
2684        clk_prepare_unlock();
2685
2686        return ret;
2687}
2688EXPORT_SYMBOL_GPL(clk_set_phase);
2689
2690static int clk_core_get_phase(struct clk_core *core)
2691{
2692        int ret;
2693
2694        lockdep_assert_held(&prepare_lock);
2695        if (!core->ops->get_phase)
2696                return 0;
2697
2698        /* Always try to update cached phase if possible */
2699        ret = core->ops->get_phase(core->hw);
2700        if (ret >= 0)
2701                core->phase = ret;
2702
2703        return ret;
2704}
2705
2706/**
2707 * clk_get_phase - return the phase shift of a clock signal
2708 * @clk: clock signal source
2709 *
2710 * Returns the phase shift of a clock node in degrees, otherwise returns
2711 * -EERROR.
2712 */
2713int clk_get_phase(struct clk *clk)
2714{
2715        int ret;
2716
2717        if (!clk)
2718                return 0;
2719
2720        clk_prepare_lock();
2721        ret = clk_core_get_phase(clk->core);
2722        clk_prepare_unlock();
2723
2724        return ret;
2725}
2726EXPORT_SYMBOL_GPL(clk_get_phase);
2727
2728static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
2729{
2730        /* Assume a default value of 50% */
2731        core->duty.num = 1;
2732        core->duty.den = 2;
2733}
2734
2735static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
2736
2737static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
2738{
2739        struct clk_duty *duty = &core->duty;
2740        int ret = 0;
2741
2742        if (!core->ops->get_duty_cycle)
2743                return clk_core_update_duty_cycle_parent_nolock(core);
2744
2745        ret = core->ops->get_duty_cycle(core->hw, duty);
2746        if (ret)
2747                goto reset;
2748
2749        /* Don't trust the clock provider too much */
2750        if (duty->den == 0 || duty->num > duty->den) {
2751                ret = -EINVAL;
2752                goto reset;
2753        }
2754
2755        return 0;
2756
2757reset:
2758        clk_core_reset_duty_cycle_nolock(core);
2759        return ret;
2760}
2761
2762static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
2763{
2764        int ret = 0;
2765
2766        if (core->parent &&
2767            core->flags & CLK_DUTY_CYCLE_PARENT) {
2768                ret = clk_core_update_duty_cycle_nolock(core->parent);
2769                memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2770        } else {
2771                clk_core_reset_duty_cycle_nolock(core);
2772        }
2773
2774        return ret;
2775}
2776
2777static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2778                                                 struct clk_duty *duty);
2779
2780static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
2781                                          struct clk_duty *duty)
2782{
2783        int ret;
2784
2785        lockdep_assert_held(&prepare_lock);
2786
2787        if (clk_core_rate_is_protected(core))
2788                return -EBUSY;
2789
2790        trace_clk_set_duty_cycle(core, duty);
2791
2792        if (!core->ops->set_duty_cycle)
2793                return clk_core_set_duty_cycle_parent_nolock(core, duty);
2794
2795        ret = core->ops->set_duty_cycle(core->hw, duty);
2796        if (!ret)
2797                memcpy(&core->duty, duty, sizeof(*duty));
2798
2799        trace_clk_set_duty_cycle_complete(core, duty);
2800
2801        return ret;
2802}
2803
2804static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
2805                                                 struct clk_duty *duty)
2806{
2807        int ret = 0;
2808
2809        if (core->parent &&
2810            core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
2811                ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
2812                memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
2813        }
2814
2815        return ret;
2816}
2817
2818/**
2819 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
2820 * @clk: clock signal source
2821 * @num: numerator of the duty cycle ratio to be applied
2822 * @den: denominator of the duty cycle ratio to be applied
2823 *
2824 * Apply the duty cycle ratio if the ratio is valid and the clock can
2825 * perform this operation
2826 *
2827 * Returns (0) on success, a negative errno otherwise.
2828 */
2829int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
2830{
2831        int ret;
2832        struct clk_duty duty;
2833
2834        if (!clk)
2835                return 0;
2836
2837        /* sanity check the ratio */
2838        if (den == 0 || num > den)
2839                return -EINVAL;
2840
2841        duty.num = num;
2842        duty.den = den;
2843
2844        clk_prepare_lock();
2845
2846        if (clk->exclusive_count)
2847                clk_core_rate_unprotect(clk->core);
2848
2849        ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
2850
2851        if (clk->exclusive_count)
2852                clk_core_rate_protect(clk->core);
2853
2854        clk_prepare_unlock();
2855
2856        return ret;
2857}
2858EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
2859
2860static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
2861                                          unsigned int scale)
2862{
2863        struct clk_duty *duty = &core->duty;
2864        int ret;
2865
2866        clk_prepare_lock();
2867
2868        ret = clk_core_update_duty_cycle_nolock(core);
2869        if (!ret)
2870                ret = mult_frac(scale, duty->num, duty->den);
2871
2872        clk_prepare_unlock();
2873
2874        return ret;
2875}
2876
2877/**
2878 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
2879 * @clk: clock signal source
2880 * @scale: scaling factor to be applied to represent the ratio as an integer
2881 *
2882 * Returns the duty cycle ratio of a clock node multiplied by the provided
2883 * scaling factor, or negative errno on error.
2884 */
2885int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
2886{
2887        if (!clk)
2888                return 0;
2889
2890        return clk_core_get_scaled_duty_cycle(clk->core, scale);
2891}
2892EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
2893
2894/**
2895 * clk_is_match - check if two clk's point to the same hardware clock
2896 * @p: clk compared against q
2897 * @q: clk compared against p
2898 *
2899 * Returns true if the two struct clk pointers both point to the same hardware
2900 * clock node. Put differently, returns true if struct clk *p and struct clk *q
2901 * share the same struct clk_core object.
2902 *
2903 * Returns false otherwise. Note that two NULL clks are treated as matching.
2904 */
2905bool clk_is_match(const struct clk *p, const struct clk *q)
2906{
2907        /* trivial case: identical struct clk's or both NULL */
2908        if (p == q)
2909                return true;
2910
2911        /* true if clk->core pointers match. Avoid dereferencing garbage */
2912        if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
2913                if (p->core == q->core)
2914                        return true;
2915
2916        return false;
2917}
2918EXPORT_SYMBOL_GPL(clk_is_match);
2919
2920/***        debugfs support        ***/
2921
2922#ifdef CONFIG_DEBUG_FS
2923#include <linux/debugfs.h>
2924
2925static struct dentry *rootdir;
2926static int inited = 0;
2927static DEFINE_MUTEX(clk_debug_lock);
2928static HLIST_HEAD(clk_debug_list);
2929
2930static struct hlist_head *orphan_list[] = {
2931        &clk_orphan_list,
2932        NULL,
2933};
2934
2935static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
2936                                 int level)
2937{
2938        int phase;
2939
2940        seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu ",
2941                   level * 3 + 1, "",
2942                   30 - level * 3, c->name,
2943                   c->enable_count, c->prepare_count, c->protect_count,
2944                   clk_core_get_rate_recalc(c),
2945                   clk_core_get_accuracy_recalc(c));
2946
2947        phase = clk_core_get_phase(c);
2948        if (phase >= 0)
2949                seq_printf(s, "%5d", phase);
2950        else
2951                seq_puts(s, "-----");
2952
2953        seq_printf(s, " %6d", clk_core_get_scaled_duty_cycle(c, 100000));
2954
2955        if (c->ops->is_enabled)
2956                seq_printf(s, " %9c\n", clk_core_is_enabled(c) ? 'Y' : 'N');
2957        else if (!c->ops->enable)
2958                seq_printf(s, " %9c\n", 'Y');
2959        else
2960                seq_printf(s, " %9c\n", '?');
2961}
2962
2963static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
2964                                     int level)
2965{
2966        struct clk_core *child;
2967
2968        clk_summary_show_one(s, c, level);
2969
2970        hlist_for_each_entry(child, &c->children, child_node)
2971                clk_summary_show_subtree(s, child, level + 1);
2972}
2973
2974static int clk_summary_show(struct seq_file *s, void *data)
2975{
2976        struct clk_core *c;
2977        struct hlist_head **lists = (struct hlist_head **)s->private;
2978
2979        seq_puts(s, "                                 enable  prepare  protect                                duty  hardware\n");
2980        seq_puts(s, "   clock                          count    count    count        rate   accuracy phase  cycle    enable\n");
2981        seq_puts(s, "-------------------------------------------------------------------------------------------------------\n");
2982
2983        clk_prepare_lock();
2984
2985        for (; *lists; lists++)
2986                hlist_for_each_entry(c, *lists, child_node)
2987                        clk_summary_show_subtree(s, c, 0);
2988
2989        clk_prepare_unlock();
2990
2991        return 0;
2992}
2993DEFINE_SHOW_ATTRIBUTE(clk_summary);
2994
2995static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
2996{
2997        int phase;
2998        unsigned long min_rate, max_rate;
2999
3000        clk_core_get_boundaries(c, &min_rate, &max_rate);
3001
3002        /* This should be JSON format, i.e. elements separated with a comma */
3003        seq_printf(s, "\"%s\": { ", c->name);
3004        seq_printf(s, "\"enable_count\": %d,", c->enable_count);
3005        seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
3006        seq_printf(s, "\"protect_count\": %d,", c->protect_count);
3007        seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c));
3008        seq_printf(s, "\"min_rate\": %lu,", min_rate);
3009        seq_printf(s, "\"max_rate\": %lu,", max_rate);
3010        seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c));
3011        phase = clk_core_get_phase(c);
3012        if (phase >= 0)
3013                seq_printf(s, "\"phase\": %d,", phase);
3014        seq_printf(s, "\"duty_cycle\": %u",
3015                   clk_core_get_scaled_duty_cycle(c, 100000));
3016}
3017
3018static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
3019{
3020        struct clk_core *child;
3021
3022        clk_dump_one(s, c, level);
3023
3024        hlist_for_each_entry(child, &c->children, child_node) {
3025                seq_putc(s, ',');
3026                clk_dump_subtree(s, child, level + 1);
3027        }
3028
3029        seq_putc(s, '}');
3030}
3031
3032static int clk_dump_show(struct seq_file *s, void *data)
3033{
3034        struct clk_core *c;
3035        bool first_node = true;
3036        struct hlist_head **lists = (struct hlist_head **)s->private;
3037
3038        seq_putc(s, '{');
3039        clk_prepare_lock();
3040
3041        for (; *lists; lists++) {
3042                hlist_for_each_entry(c, *lists, child_node) {
3043                        if (!first_node)
3044                                seq_putc(s, ',');
3045                        first_node = false;
3046                        clk_dump_subtree(s, c, 0);
3047                }
3048        }
3049
3050        clk_prepare_unlock();
3051
3052        seq_puts(s, "}\n");
3053        return 0;
3054}
3055DEFINE_SHOW_ATTRIBUTE(clk_dump);
3056
3057#undef CLOCK_ALLOW_WRITE_DEBUGFS
3058#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3059/*
3060 * This can be dangerous, therefore don't provide any real compile time
3061 * configuration option for this feature.
3062 * People who want to use this will need to modify the source code directly.
3063 */
3064static int clk_rate_set(void *data, u64 val)
3065{
3066        struct clk_core *core = data;
3067        int ret;
3068
3069        clk_prepare_lock();
3070        ret = clk_core_set_rate_nolock(core, val);
3071        clk_prepare_unlock();
3072
3073        return ret;
3074}
3075
3076#define clk_rate_mode   0644
3077
3078static int clk_prepare_enable_set(void *data, u64 val)
3079{
3080        struct clk_core *core = data;
3081        int ret = 0;
3082
3083        if (val)
3084                ret = clk_prepare_enable(core->hw->clk);
3085        else
3086                clk_disable_unprepare(core->hw->clk);
3087
3088        return ret;
3089}
3090
3091static int clk_prepare_enable_get(void *data, u64 *val)
3092{
3093        struct clk_core *core = data;
3094
3095        *val = core->enable_count && core->prepare_count;
3096        return 0;
3097}
3098
3099DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get,
3100                         clk_prepare_enable_set, "%llu\n");
3101
3102#else
3103#define clk_rate_set    NULL
3104#define clk_rate_mode   0444
3105#endif
3106
3107static int clk_rate_get(void *data, u64 *val)
3108{
3109        struct clk_core *core = data;
3110
3111        *val = core->rate;
3112        return 0;
3113}
3114
3115DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");
3116
3117static const struct {
3118        unsigned long flag;
3119        const char *name;
3120} clk_flags[] = {
3121#define ENTRY(f) { f, #f }
3122        ENTRY(CLK_SET_RATE_GATE),
3123        ENTRY(CLK_SET_PARENT_GATE),
3124        ENTRY(CLK_SET_RATE_PARENT),
3125        ENTRY(CLK_IGNORE_UNUSED),
3126        ENTRY(CLK_GET_RATE_NOCACHE),
3127        ENTRY(CLK_SET_RATE_NO_REPARENT),
3128        ENTRY(CLK_GET_ACCURACY_NOCACHE),
3129        ENTRY(CLK_RECALC_NEW_RATES),
3130        ENTRY(CLK_SET_RATE_UNGATE),
3131        ENTRY(CLK_IS_CRITICAL),
3132        ENTRY(CLK_OPS_PARENT_ENABLE),
3133        ENTRY(CLK_DUTY_CYCLE_PARENT),
3134#undef ENTRY
3135};
3136
3137static int clk_flags_show(struct seq_file *s, void *data)
3138{
3139        struct clk_core *core = s->private;
3140        unsigned long flags = core->flags;
3141        unsigned int i;
3142
3143        for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
3144                if (flags & clk_flags[i].flag) {
3145                        seq_printf(s, "%s\n", clk_flags[i].name);
3146                        flags &= ~clk_flags[i].flag;
3147                }
3148        }
3149        if (flags) {
3150                /* Unknown flags */
3151                seq_printf(s, "0x%lx\n", flags);
3152        }
3153
3154        return 0;
3155}
3156DEFINE_SHOW_ATTRIBUTE(clk_flags);
3157
3158static void possible_parent_show(struct seq_file *s, struct clk_core *core,
3159                                 unsigned int i, char terminator)
3160{
3161        struct clk_core *parent;
3162
3163        /*
3164         * Go through the following options to fetch a parent's name.
3165         *
3166         * 1. Fetch the registered parent clock and use its name
3167         * 2. Use the global (fallback) name if specified
3168         * 3. Use the local fw_name if provided
3169         * 4. Fetch parent clock's clock-output-name if DT index was set
3170         *
3171         * This may still fail in some cases, such as when the parent is
3172         * specified directly via a struct clk_hw pointer, but it isn't
3173         * registered (yet).
3174         */
3175        parent = clk_core_get_parent_by_index(core, i);
3176        if (parent)
3177                seq_puts(s, parent->name);
3178        else if (core->parents[i].name)
3179                seq_puts(s, core->parents[i].name);
3180        else if (core->parents[i].fw_name)
3181                seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
3182        else if (core->parents[i].index >= 0)
3183                seq_puts(s,
3184                         of_clk_get_parent_name(core->of_node,
3185                                                core->parents[i].index));
3186        else
3187                seq_puts(s, "(missing)");
3188
3189        seq_putc(s, terminator);
3190}
3191
3192static int possible_parents_show(struct seq_file *s, void *data)
3193{
3194        struct clk_core *core = s->private;
3195        int i;
3196
3197        for (i = 0; i < core->num_parents - 1; i++)
3198                possible_parent_show(s, core, i, ' ');
3199
3200        possible_parent_show(s, core, i, '\n');
3201
3202        return 0;
3203}
3204DEFINE_SHOW_ATTRIBUTE(possible_parents);
3205
3206static int current_parent_show(struct seq_file *s, void *data)
3207{
3208        struct clk_core *core = s->private;
3209
3210        if (core->parent)
3211                seq_printf(s, "%s\n", core->parent->name);
3212
3213        return 0;
3214}
3215DEFINE_SHOW_ATTRIBUTE(current_parent);
3216
3217static int clk_duty_cycle_show(struct seq_file *s, void *data)
3218{
3219        struct clk_core *core = s->private;
3220        struct clk_duty *duty = &core->duty;
3221
3222        seq_printf(s, "%u/%u\n", duty->num, duty->den);
3223
3224        return 0;
3225}
3226DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
3227
3228static int clk_min_rate_show(struct seq_file *s, void *data)
3229{
3230        struct clk_core *core = s->private;
3231        unsigned long min_rate, max_rate;
3232
3233        clk_prepare_lock();
3234        clk_core_get_boundaries(core, &min_rate, &max_rate);
3235        clk_prepare_unlock();
3236        seq_printf(s, "%lu\n", min_rate);
3237
3238        return 0;
3239}
3240DEFINE_SHOW_ATTRIBUTE(clk_min_rate);
3241
3242static int clk_max_rate_show(struct seq_file *s, void *data)
3243{
3244        struct clk_core *core = s->private;
3245        unsigned long min_rate, max_rate;
3246
3247        clk_prepare_lock();
3248        clk_core_get_boundaries(core, &min_rate, &max_rate);
3249        clk_prepare_unlock();
3250        seq_printf(s, "%lu\n", max_rate);
3251
3252        return 0;
3253}
3254DEFINE_SHOW_ATTRIBUTE(clk_max_rate);
3255
3256static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
3257{
3258        struct dentry *root;
3259
3260        if (!core || !pdentry)
3261                return;
3262
3263        root = debugfs_create_dir(core->name, pdentry);
3264        core->dentry = root;
3265
3266        debugfs_create_file("clk_rate", clk_rate_mode, root, core,
3267                            &clk_rate_fops);
3268        debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
3269        debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
3270        debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
3271        debugfs_create_u32("clk_phase", 0444, root, &core->phase);
3272        debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
3273        debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
3274        debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
3275        debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
3276        debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
3277        debugfs_create_file("clk_duty_cycle", 0444, root, core,
3278                            &clk_duty_cycle_fops);
3279#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3280        debugfs_create_file("clk_prepare_enable", 0644, root, core,
3281                            &clk_prepare_enable_fops);
3282#endif
3283
3284        if (core->num_parents > 0)
3285                debugfs_create_file("clk_parent", 0444, root, core,
3286                                    &current_parent_fops);
3287
3288        if (core->num_parents > 1)
3289                debugfs_create_file("clk_possible_parents", 0444, root, core,
3290                                    &possible_parents_fops);
3291
3292        if (core->ops->debug_init)
3293                core->ops->debug_init(core->hw, core->dentry);
3294}
3295
3296/**
3297 * clk_debug_register - add a clk node to the debugfs clk directory
3298 * @core: the clk being added to the debugfs clk directory
3299 *
3300 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
3301 * initialized.  Otherwise it bails out early since the debugfs clk directory
3302 * will be created lazily by clk_debug_init as part of a late_initcall.
3303 */
3304static void clk_debug_register(struct clk_core *core)
3305{
3306        mutex_lock(&clk_debug_lock);
3307        hlist_add_head(&core->debug_node, &clk_debug_list);
3308        if (inited)
3309                clk_debug_create_one(core, rootdir);
3310        mutex_unlock(&clk_debug_lock);
3311}
3312
3313 /**
3314 * clk_debug_unregister - remove a clk node from the debugfs clk directory
3315 * @core: the clk being removed from the debugfs clk directory
3316 *
3317 * Dynamically removes a clk and all its child nodes from the
3318 * debugfs clk directory if clk->dentry points to debugfs created by
3319 * clk_debug_register in __clk_core_init.
3320 */
3321static void clk_debug_unregister(struct clk_core *core)
3322{
3323        mutex_lock(&clk_debug_lock);
3324        hlist_del_init(&core->debug_node);
3325        debugfs_remove_recursive(core->dentry);
3326        core->dentry = NULL;
3327        mutex_unlock(&clk_debug_lock);
3328}
3329
3330/**
3331 * clk_debug_init - lazily populate the debugfs clk directory
3332 *
3333 * clks are often initialized very early during boot before memory can be
3334 * dynamically allocated and well before debugfs is setup. This function
3335 * populates the debugfs clk directory once at boot-time when we know that
3336 * debugfs is setup. It should only be called once at boot-time, all other clks
3337 * added dynamically will be done so with clk_debug_register.
3338 */
3339static int __init clk_debug_init(void)
3340{
3341        struct clk_core *core;
3342
3343        rootdir = debugfs_create_dir("clk", NULL);
3344
3345        debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
3346                            &clk_summary_fops);
3347        debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
3348                            &clk_dump_fops);
3349        debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
3350                            &clk_summary_fops);
3351        debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
3352                            &clk_dump_fops);
3353
3354        mutex_lock(&clk_debug_lock);
3355        hlist_for_each_entry(core, &clk_debug_list, debug_node)
3356                clk_debug_create_one(core, rootdir);
3357
3358        inited = 1;
3359        mutex_unlock(&clk_debug_lock);
3360
3361        return 0;
3362}
3363late_initcall(clk_debug_init);
3364#else
3365static inline void clk_debug_register(struct clk_core *core) { }
3366static inline void clk_debug_unregister(struct clk_core *core)
3367{
3368}
3369#endif
3370
3371static void clk_core_reparent_orphans_nolock(void)
3372{
3373        struct clk_core *orphan;
3374        struct hlist_node *tmp2;
3375
3376        /*
3377         * walk the list of orphan clocks and reparent any that newly finds a
3378         * parent.
3379         */
3380        hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3381                struct clk_core *parent = __clk_init_parent(orphan);
3382
3383                /*
3384                 * We need to use __clk_set_parent_before() and _after() to
3385                 * to properly migrate any prepare/enable count of the orphan
3386                 * clock. This is important for CLK_IS_CRITICAL clocks, which
3387                 * are enabled during init but might not have a parent yet.
3388                 */
3389                if (parent) {
3390                        /* update the clk tree topology */
3391                        __clk_set_parent_before(orphan, parent);
3392                        __clk_set_parent_after(orphan, parent, NULL);
3393                        __clk_recalc_accuracies(orphan);
3394                        __clk_recalc_rates(orphan, 0);
3395                }
3396        }
3397}
3398
3399/**
3400 * __clk_core_init - initialize the data structures in a struct clk_core
3401 * @core:       clk_core being initialized
3402 *
3403 * Initializes the lists in struct clk_core, queries the hardware for the
3404 * parent and rate and sets them both.
3405 */
3406static int __clk_core_init(struct clk_core *core)
3407{
3408        int ret;
3409        struct clk_core *parent;
3410        unsigned long rate;
3411        int phase;
3412
3413        if (!core)
3414                return -EINVAL;
3415
3416        clk_prepare_lock();
3417
3418        ret = clk_pm_runtime_get(core);
3419        if (ret)
3420                goto unlock;
3421
3422        /* check to see if a clock with this name is already registered */
3423        if (clk_core_lookup(core->name)) {
3424                pr_debug("%s: clk %s already initialized\n",
3425                                __func__, core->name);
3426                ret = -EEXIST;
3427                goto out;
3428        }
3429
3430        /* check that clk_ops are sane.  See Documentation/driver-api/clk.rst */
3431        if (core->ops->set_rate &&
3432            !((core->ops->round_rate || core->ops->determine_rate) &&
3433              core->ops->recalc_rate)) {
3434                pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
3435                       __func__, core->name);
3436                ret = -EINVAL;
3437                goto out;
3438        }
3439
3440        if (core->ops->set_parent && !core->ops->get_parent) {
3441                pr_err("%s: %s must implement .get_parent & .set_parent\n",
3442                       __func__, core->name);
3443                ret = -EINVAL;
3444                goto out;
3445        }
3446
3447        if (core->num_parents > 1 && !core->ops->get_parent) {
3448                pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3449                       __func__, core->name);
3450                ret = -EINVAL;
3451                goto out;
3452        }
3453
3454        if (core->ops->set_rate_and_parent &&
3455                        !(core->ops->set_parent && core->ops->set_rate)) {
3456                pr_err("%s: %s must implement .set_parent & .set_rate\n",
3457                                __func__, core->name);
3458                ret = -EINVAL;
3459                goto out;
3460        }
3461
3462        /*
3463         * optional platform-specific magic
3464         *
3465         * The .init callback is not used by any of the basic clock types, but
3466         * exists for weird hardware that must perform initialization magic for
3467         * CCF to get an accurate view of clock for any other callbacks. It may
3468         * also be used needs to perform dynamic allocations. Such allocation
3469         * must be freed in the terminate() callback.
3470         * This callback shall not be used to initialize the parameters state,
3471         * such as rate, parent, etc ...
3472         *
3473         * If it exist, this callback should called before any other callback of
3474         * the clock
3475         */
3476        if (core->ops->init) {
3477                ret = core->ops->init(core->hw);
3478                if (ret)
3479                        goto out;
3480        }
3481
3482        parent = core->parent = __clk_init_parent(core);
3483
3484        /*
3485         * Populate core->parent if parent has already been clk_core_init'd. If
3486         * parent has not yet been clk_core_init'd then place clk in the orphan
3487         * list.  If clk doesn't have any parents then place it in the root
3488         * clk list.
3489         *
3490         * Every time a new clk is clk_init'd then we walk the list of orphan
3491         * clocks and re-parent any that are children of the clock currently
3492         * being clk_init'd.
3493         */
3494        if (parent) {
3495                hlist_add_head(&core->child_node, &parent->children);
3496                core->orphan = parent->orphan;
3497        } else if (!core->num_parents) {
3498                hlist_add_head(&core->child_node, &clk_root_list);
3499                core->orphan = false;
3500        } else {
3501                hlist_add_head(&core->child_node, &clk_orphan_list);
3502                core->orphan = true;
3503        }
3504
3505        /*
3506         * Set clk's accuracy.  The preferred method is to use
3507         * .recalc_accuracy. For simple clocks and lazy developers the default
3508         * fallback is to use the parent's accuracy.  If a clock doesn't have a
3509         * parent (or is orphaned) then accuracy is set to zero (perfect
3510         * clock).
3511         */
3512        if (core->ops->recalc_accuracy)
3513                core->accuracy = core->ops->recalc_accuracy(core->hw,
3514                                        clk_core_get_accuracy_no_lock(parent));
3515        else if (parent)
3516                core->accuracy = parent->accuracy;
3517        else
3518                core->accuracy = 0;
3519
3520        /*
3521         * Set clk's phase by clk_core_get_phase() caching the phase.
3522         * Since a phase is by definition relative to its parent, just
3523         * query the current clock phase, or just assume it's in phase.
3524         */
3525        phase = clk_core_get_phase(core);
3526        if (phase < 0) {
3527                ret = phase;
3528                pr_warn("%s: Failed to get phase for clk '%s'\n", __func__,
3529                        core->name);
3530                goto out;
3531        }
3532
3533        /*
3534         * Set clk's duty cycle.
3535         */
3536        clk_core_update_duty_cycle_nolock(core);
3537
3538        /*
3539         * Set clk's rate.  The preferred method is to use .recalc_rate.  For
3540         * simple clocks and lazy developers the default fallback is to use the
3541         * parent's rate.  If a clock doesn't have a parent (or is orphaned)
3542         * then rate is set to zero.
3543         */
3544        if (core->ops->recalc_rate)
3545                rate = core->ops->recalc_rate(core->hw,
3546                                clk_core_get_rate_nolock(parent));
3547        else if (parent)
3548                rate = parent->rate;
3549        else
3550                rate = 0;
3551        core->rate = core->req_rate = rate;
3552
3553        /*
3554         * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3555         * don't get accidentally disabled when walking the orphan tree and
3556         * reparenting clocks
3557         */
3558        if (core->flags & CLK_IS_CRITICAL) {
3559                ret = clk_core_prepare(core);
3560                if (ret) {
3561                        pr_warn("%s: critical clk '%s' failed to prepare\n",
3562                               __func__, core->name);
3563                        goto out;
3564                }
3565
3566                ret = clk_core_enable_lock(core);
3567                if (ret) {
3568                        pr_warn("%s: critical clk '%s' failed to enable\n",
3569                               __func__, core->name);
3570                        clk_core_unprepare(core);
3571                        goto out;
3572                }
3573        }
3574
3575        clk_core_reparent_orphans_nolock();
3576
3577
3578        kref_init(&core->ref);
3579out:
3580        clk_pm_runtime_put(core);
3581unlock:
3582        if (ret)
3583                hlist_del_init(&core->child_node);
3584
3585        clk_prepare_unlock();
3586
3587        if (!ret)
3588                clk_debug_register(core);
3589
3590        return ret;
3591}
3592
3593/**
3594 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
3595 * @core: clk to add consumer to
3596 * @clk: consumer to link to a clk
3597 */
3598static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
3599{
3600        clk_prepare_lock();
3601        hlist_add_head(&clk->clks_node, &core->clks);
3602        clk_prepare_unlock();
3603}
3604
3605/**
3606 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
3607 * @clk: consumer to unlink
3608 */
3609static void clk_core_unlink_consumer(struct clk *clk)
3610{
3611        lockdep_assert_held(&prepare_lock);
3612        hlist_del(&clk->clks_node);
3613}
3614
3615/**
3616 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
3617 * @core: clk to allocate a consumer for
3618 * @dev_id: string describing device name
3619 * @con_id: connection ID string on device
3620 *
3621 * Returns: clk consumer left unlinked from the consumer list
3622 */
3623static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
3624                             const char *con_id)
3625{
3626        struct clk *clk;
3627
3628        clk = kzalloc(sizeof(*clk), GFP_KERNEL);
3629        if (!clk)
3630                return ERR_PTR(-ENOMEM);
3631
3632        clk->core = core;
3633        clk->dev_id = dev_id;
3634        clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
3635        clk->max_rate = ULONG_MAX;
3636
3637        return clk;
3638}
3639
3640/**
3641 * free_clk - Free a clk consumer
3642 * @clk: clk consumer to free
3643 *
3644 * Note, this assumes the clk has been unlinked from the clk_core consumer
3645 * list.
3646 */
3647static void free_clk(struct clk *clk)
3648{
3649        kfree_const(clk->con_id);
3650        kfree(clk);
3651}
3652
3653/**
3654 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
3655 * a clk_hw
3656 * @dev: clk consumer device
3657 * @hw: clk_hw associated with the clk being consumed
3658 * @dev_id: string describing device name
3659 * @con_id: connection ID string on device
3660 *
3661 * This is the main function used to create a clk pointer for use by clk
3662 * consumers. It connects a consumer to the clk_core and clk_hw structures
3663 * used by the framework and clk provider respectively.
3664 */
3665struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
3666                              const char *dev_id, const char *con_id)
3667{
3668        struct clk *clk;
3669        struct clk_core *core;
3670
3671        /* This is to allow this function to be chained to others */
3672        if (IS_ERR_OR_NULL(hw))
3673                return ERR_CAST(hw);
3674
3675        core = hw->core;
3676        clk = alloc_clk(core, dev_id, con_id);
3677        if (IS_ERR(clk))
3678                return clk;
3679        clk->dev = dev;
3680
3681        if (!try_module_get(core->owner)) {
3682                free_clk(clk);
3683                return ERR_PTR(-ENOENT);
3684        }
3685
3686        kref_get(&core->ref);
3687        clk_core_link_consumer(core, clk);
3688
3689        return clk;
3690}
3691
3692/**
3693 * clk_hw_get_clk - get clk consumer given an clk_hw
3694 * @hw: clk_hw associated with the clk being consumed
3695 * @con_id: connection ID string on device
3696 *
3697 * Returns: new clk consumer
3698 * This is the function to be used by providers which need
3699 * to get a consumer clk and act on the clock element
3700 * Calls to this function must be balanced with calls clk_put()
3701 */
3702struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id)
3703{
3704        struct device *dev = hw->core->dev;
3705
3706        return clk_hw_create_clk(dev, hw, dev_name(dev), con_id);
3707}
3708EXPORT_SYMBOL(clk_hw_get_clk);
3709
3710static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
3711{
3712        const char *dst;
3713
3714        if (!src) {
3715                if (must_exist)
3716                        return -EINVAL;
3717                return 0;
3718        }
3719
3720        *dst_p = dst = kstrdup_const(src, GFP_KERNEL);
3721        if (!dst)
3722                return -ENOMEM;
3723
3724        return 0;
3725}
3726
3727static int clk_core_populate_parent_map(struct clk_core *core,
3728                                        const struct clk_init_data *init)
3729{
3730        u8 num_parents = init->num_parents;
3731        const char * const *parent_names = init->parent_names;
3732        const struct clk_hw **parent_hws = init->parent_hws;
3733        const struct clk_parent_data *parent_data = init->parent_data;
3734        int i, ret = 0;
3735        struct clk_parent_map *parents, *parent;
3736
3737        if (!num_parents)
3738                return 0;
3739
3740        /*
3741         * Avoid unnecessary string look-ups of clk_core's possible parents by
3742         * having a cache of names/clk_hw pointers to clk_core pointers.
3743         */
3744        parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
3745        core->parents = parents;
3746        if (!parents)
3747                return -ENOMEM;
3748
3749        /* Copy everything over because it might be __initdata */
3750        for (i = 0, parent = parents; i < num_parents; i++, parent++) {
3751                parent->index = -1;
3752                if (parent_names) {
3753                        /* throw a WARN if any entries are NULL */
3754                        WARN(!parent_names[i],
3755                                "%s: invalid NULL in %s's .parent_names\n",
3756                                __func__, core->name);
3757                        ret = clk_cpy_name(&parent->name, parent_names[i],
3758                                           true);
3759                } else if (parent_data) {
3760                        parent->hw = parent_data[i].hw;
3761                        parent->index = parent_data[i].index;
3762                        ret = clk_cpy_name(&parent->fw_name,
3763                                           parent_data[i].fw_name, false);
3764                        if (!ret)
3765                                ret = clk_cpy_name(&parent->name,
3766                                                   parent_data[i].name,
3767                                                   false);
3768                } else if (parent_hws) {
3769                        parent->hw = parent_hws[i];
3770                } else {
3771                        ret = -EINVAL;
3772                        WARN(1, "Must specify parents if num_parents > 0\n");
3773                }
3774
3775                if (ret) {
3776                        do {
3777                                kfree_const(parents[i].name);
3778                                kfree_const(parents[i].fw_name);
3779                        } while (--i >= 0);
3780                        kfree(parents);
3781
3782                        return ret;
3783                }
3784        }
3785
3786        return 0;
3787}
3788
3789static void clk_core_free_parent_map(struct clk_core *core)
3790{
3791        int i = core->num_parents;
3792
3793        if (!core->num_parents)
3794                return;
3795
3796        while (--i >= 0) {
3797                kfree_const(core->parents[i].name);
3798                kfree_const(core->parents[i].fw_name);
3799        }
3800
3801        kfree(core->parents);
3802}
3803
3804static struct clk *
3805__clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
3806{
3807        int ret;
3808        struct clk_core *core;
3809        const struct clk_init_data *init = hw->init;
3810
3811        /*
3812         * The init data is not supposed to be used outside of registration path.
3813         * Set it to NULL so that provider drivers can't use it either and so that
3814         * we catch use of hw->init early on in the core.
3815         */
3816        hw->init = NULL;
3817
3818        core = kzalloc(sizeof(*core), GFP_KERNEL);
3819        if (!core) {
3820                ret = -ENOMEM;
3821                goto fail_out;
3822        }
3823
3824        core->name = kstrdup_const(init->name, GFP_KERNEL);
3825        if (!core->name) {
3826                ret = -ENOMEM;
3827                goto fail_name;
3828        }
3829
3830        if (WARN_ON(!init->ops)) {
3831                ret = -EINVAL;
3832                goto fail_ops;
3833        }
3834        core->ops = init->ops;
3835
3836        if (dev && pm_runtime_enabled(dev))
3837                core->rpm_enabled = true;
3838        core->dev = dev;
3839        core->of_node = np;
3840        if (dev && dev->driver)
3841                core->owner = dev->driver->owner;
3842        core->hw = hw;
3843        core->flags = init->flags;
3844        core->num_parents = init->num_parents;
3845        core->min_rate = 0;
3846        core->max_rate = ULONG_MAX;
3847        hw->core = core;
3848
3849        ret = clk_core_populate_parent_map(core, init);
3850        if (ret)
3851                goto fail_parents;
3852
3853        INIT_HLIST_HEAD(&core->clks);
3854
3855        /*
3856         * Don't call clk_hw_create_clk() here because that would pin the
3857         * provider module to itself and prevent it from ever being removed.
3858         */
3859        hw->clk = alloc_clk(core, NULL, NULL);
3860        if (IS_ERR(hw->clk)) {
3861                ret = PTR_ERR(hw->clk);
3862                goto fail_create_clk;
3863        }
3864
3865        clk_core_link_consumer(hw->core, hw->clk);
3866
3867        ret = __clk_core_init(core);
3868        if (!ret)
3869                return hw->clk;
3870
3871        clk_prepare_lock();
3872        clk_core_unlink_consumer(hw->clk);
3873        clk_prepare_unlock();
3874
3875        free_clk(hw->clk);
3876        hw->clk = NULL;
3877
3878fail_create_clk:
3879        clk_core_free_parent_map(core);
3880fail_parents:
3881fail_ops:
3882        kfree_const(core->name);
3883fail_name:
3884        kfree(core);
3885fail_out:
3886        return ERR_PTR(ret);
3887}
3888
3889/**
3890 * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
3891 * @dev: Device to get device node of
3892 *
3893 * Return: device node pointer of @dev, or the device node pointer of
3894 * @dev->parent if dev doesn't have a device node, or NULL if neither
3895 * @dev or @dev->parent have a device node.
3896 */
3897static struct device_node *dev_or_parent_of_node(struct device *dev)
3898{
3899        struct device_node *np;
3900
3901        if (!dev)
3902                return NULL;
3903
3904        np = dev_of_node(dev);
3905        if (!np)
3906                np = dev_of_node(dev->parent);
3907
3908        return np;
3909}
3910
3911/**
3912 * clk_register - allocate a new clock, register it and return an opaque cookie
3913 * @dev: device that is registering this clock
3914 * @hw: link to hardware-specific clock data
3915 *
3916 * clk_register is the *deprecated* interface for populating the clock tree with
3917 * new clock nodes. Use clk_hw_register() instead.
3918 *
3919 * Returns: a pointer to the newly allocated struct clk which
3920 * cannot be dereferenced by driver code but may be used in conjunction with the
3921 * rest of the clock API.  In the event of an error clk_register will return an
3922 * error code; drivers must test for an error code after calling clk_register.
3923 */
3924struct clk *clk_register(struct device *dev, struct clk_hw *hw)
3925{
3926        return __clk_register(dev, dev_or_parent_of_node(dev), hw);
3927}
3928EXPORT_SYMBOL_GPL(clk_register);
3929
3930/**
3931 * clk_hw_register - register a clk_hw and return an error code
3932 * @dev: device that is registering this clock
3933 * @hw: link to hardware-specific clock data
3934 *
3935 * clk_hw_register is the primary interface for populating the clock tree with
3936 * new clock nodes. It returns an integer equal to zero indicating success or
3937 * less than zero indicating failure. Drivers must test for an error code after
3938 * calling clk_hw_register().
3939 */
3940int clk_hw_register(struct device *dev, struct clk_hw *hw)
3941{
3942        return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
3943                               hw));
3944}
3945EXPORT_SYMBOL_GPL(clk_hw_register);
3946
3947/*
3948 * of_clk_hw_register - register a clk_hw and return an error code
3949 * @node: device_node of device that is registering this clock
3950 * @hw: link to hardware-specific clock data
3951 *
3952 * of_clk_hw_register() is the primary interface for populating the clock tree
3953 * with new clock nodes when a struct device is not available, but a struct
3954 * device_node is. It returns an integer equal to zero indicating success or
3955 * less than zero indicating failure. Drivers must test for an error code after
3956 * calling of_clk_hw_register().
3957 */
3958int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
3959{
3960        return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
3961}
3962EXPORT_SYMBOL_GPL(of_clk_hw_register);
3963
3964/* Free memory allocated for a clock. */
3965static void __clk_release(struct kref *ref)
3966{
3967        struct clk_core *core = container_of(ref, struct clk_core, ref);
3968
3969        lockdep_assert_held(&prepare_lock);
3970
3971        clk_core_free_parent_map(core);
3972        kfree_const(core->name);
3973        kfree(core);
3974}
3975
3976/*
3977 * Empty clk_ops for unregistered clocks. These are used temporarily
3978 * after clk_unregister() was called on a clock and until last clock
3979 * consumer calls clk_put() and the struct clk object is freed.
3980 */
3981static int clk_nodrv_prepare_enable(struct clk_hw *hw)
3982{
3983        return -ENXIO;
3984}
3985
3986static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
3987{
3988        WARN_ON_ONCE(1);
3989}
3990
3991static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
3992                                        unsigned long parent_rate)
3993{
3994        return -ENXIO;
3995}
3996
3997static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
3998{
3999        return -ENXIO;
4000}
4001
4002static const struct clk_ops clk_nodrv_ops = {
4003        .enable         = clk_nodrv_prepare_enable,
4004        .disable        = clk_nodrv_disable_unprepare,
4005        .prepare        = clk_nodrv_prepare_enable,
4006        .unprepare      = clk_nodrv_disable_unprepare,
4007        .set_rate       = clk_nodrv_set_rate,
4008        .set_parent     = clk_nodrv_set_parent,
4009};
4010
4011static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
4012                                                struct clk_core *target)
4013{
4014        int i;
4015        struct clk_core *child;
4016
4017        for (i = 0; i < root->num_parents; i++)
4018                if (root->parents[i].core == target)
4019                        root->parents[i].core = NULL;
4020
4021        hlist_for_each_entry(child, &root->children, child_node)
4022                clk_core_evict_parent_cache_subtree(child, target);
4023}
4024
4025/* Remove this clk from all parent caches */
4026static void clk_core_evict_parent_cache(struct clk_core *core)
4027{
4028        struct hlist_head **lists;
4029        struct clk_core *root;
4030
4031        lockdep_assert_held(&prepare_lock);
4032
4033        for (lists = all_lists; *lists; lists++)
4034                hlist_for_each_entry(root, *lists, child_node)
4035                        clk_core_evict_parent_cache_subtree(root, core);
4036
4037}
4038
4039/**
4040 * clk_unregister - unregister a currently registered clock
4041 * @clk: clock to unregister
4042 */
4043void clk_unregister(struct clk *clk)
4044{
4045        unsigned long flags;
4046        const struct clk_ops *ops;
4047
4048        if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4049                return;
4050
4051        clk_debug_unregister(clk->core);
4052
4053        clk_prepare_lock();
4054
4055        ops = clk->core->ops;
4056        if (ops == &clk_nodrv_ops) {
4057                pr_err("%s: unregistered clock: %s\n", __func__,
4058                       clk->core->name);
4059                goto unlock;
4060        }
4061        /*
4062         * Assign empty clock ops for consumers that might still hold
4063         * a reference to this clock.
4064         */
4065        flags = clk_enable_lock();
4066        clk->core->ops = &clk_nodrv_ops;
4067        clk_enable_unlock(flags);
4068
4069        if (ops->terminate)
4070                ops->terminate(clk->core->hw);
4071
4072        if (!hlist_empty(&clk->core->children)) {
4073                struct clk_core *child;
4074                struct hlist_node *t;
4075
4076                /* Reparent all children to the orphan list. */
4077                hlist_for_each_entry_safe(child, t, &clk->core->children,
4078                                          child_node)
4079                        clk_core_set_parent_nolock(child, NULL);
4080        }
4081
4082        clk_core_evict_parent_cache(clk->core);
4083
4084        hlist_del_init(&clk->core->child_node);
4085
4086        if (clk->core->prepare_count)
4087                pr_warn("%s: unregistering prepared clock: %s\n",
4088                                        __func__, clk->core->name);
4089
4090        if (clk->core->protect_count)
4091                pr_warn("%s: unregistering protected clock: %s\n",
4092                                        __func__, clk->core->name);
4093
4094        kref_put(&clk->core->ref, __clk_release);
4095        free_clk(clk);
4096unlock:
4097        clk_prepare_unlock();
4098}
4099EXPORT_SYMBOL_GPL(clk_unregister);
4100
4101/**
4102 * clk_hw_unregister - unregister a currently registered clk_hw
4103 * @hw: hardware-specific clock data to unregister
4104 */
4105void clk_hw_unregister(struct clk_hw *hw)
4106{
4107        clk_unregister(hw->clk);
4108}
4109EXPORT_SYMBOL_GPL(clk_hw_unregister);
4110
4111static void devm_clk_unregister_cb(struct device *dev, void *res)
4112{
4113        clk_unregister(*(struct clk **)res);
4114}
4115
4116static void devm_clk_hw_unregister_cb(struct device *dev, void *res)
4117{
4118        clk_hw_unregister(*(struct clk_hw **)res);
4119}
4120
4121/**
4122 * devm_clk_register - resource managed clk_register()
4123 * @dev: device that is registering this clock
4124 * @hw: link to hardware-specific clock data
4125 *
4126 * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
4127 *
4128 * Clocks returned from this function are automatically clk_unregister()ed on
4129 * driver detach. See clk_register() for more information.
4130 */
4131struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
4132{
4133        struct clk *clk;
4134        struct clk **clkp;
4135
4136        clkp = devres_alloc(devm_clk_unregister_cb, sizeof(*clkp), GFP_KERNEL);
4137        if (!clkp)
4138                return ERR_PTR(-ENOMEM);
4139
4140        clk = clk_register(dev, hw);
4141        if (!IS_ERR(clk)) {
4142                *clkp = clk;
4143                devres_add(dev, clkp);
4144        } else {
4145                devres_free(clkp);
4146        }
4147
4148        return clk;
4149}
4150EXPORT_SYMBOL_GPL(devm_clk_register);
4151
4152/**
4153 * devm_clk_hw_register - resource managed clk_hw_register()
4154 * @dev: device that is registering this clock
4155 * @hw: link to hardware-specific clock data
4156 *
4157 * Managed clk_hw_register(). Clocks registered by this function are
4158 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
4159 * for more information.
4160 */
4161int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
4162{
4163        struct clk_hw **hwp;
4164        int ret;
4165
4166        hwp = devres_alloc(devm_clk_hw_unregister_cb, sizeof(*hwp), GFP_KERNEL);
4167        if (!hwp)
4168                return -ENOMEM;
4169
4170        ret = clk_hw_register(dev, hw);
4171        if (!ret) {
4172                *hwp = hw;
4173                devres_add(dev, hwp);
4174        } else {
4175                devres_free(hwp);
4176        }
4177
4178        return ret;
4179}
4180EXPORT_SYMBOL_GPL(devm_clk_hw_register);
4181
4182static int devm_clk_match(struct device *dev, void *res, void *data)
4183{
4184        struct clk *c = res;
4185        if (WARN_ON(!c))
4186                return 0;
4187        return c == data;
4188}
4189
4190static int devm_clk_hw_match(struct device *dev, void *res, void *data)
4191{
4192        struct clk_hw *hw = res;
4193
4194        if (WARN_ON(!hw))
4195                return 0;
4196        return hw == data;
4197}
4198
4199/**
4200 * devm_clk_unregister - resource managed clk_unregister()
4201 * @dev: device that is unregistering the clock data
4202 * @clk: clock to unregister
4203 *
4204 * Deallocate a clock allocated with devm_clk_register(). Normally
4205 * this function will not need to be called and the resource management
4206 * code will ensure that the resource is freed.
4207 */
4208void devm_clk_unregister(struct device *dev, struct clk *clk)
4209{
4210        WARN_ON(devres_release(dev, devm_clk_unregister_cb, devm_clk_match, clk));
4211}
4212EXPORT_SYMBOL_GPL(devm_clk_unregister);
4213
4214/**
4215 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
4216 * @dev: device that is unregistering the hardware-specific clock data
4217 * @hw: link to hardware-specific clock data
4218 *
4219 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
4220 * this function will not need to be called and the resource management
4221 * code will ensure that the resource is freed.
4222 */
4223void devm_clk_hw_unregister(struct device *dev, struct clk_hw *hw)
4224{
4225        WARN_ON(devres_release(dev, devm_clk_hw_unregister_cb, devm_clk_hw_match,
4226                                hw));
4227}
4228EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);
4229
4230static void devm_clk_release(struct device *dev, void *res)
4231{
4232        clk_put(*(struct clk **)res);
4233}
4234
4235/**
4236 * devm_clk_hw_get_clk - resource managed clk_hw_get_clk()
4237 * @dev: device that is registering this clock
4238 * @hw: clk_hw associated with the clk being consumed
4239 * @con_id: connection ID string on device
4240 *
4241 * Managed clk_hw_get_clk(). Clocks got with this function are
4242 * automatically clk_put() on driver detach. See clk_put()
4243 * for more information.
4244 */
4245struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw,
4246                                const char *con_id)
4247{
4248        struct clk *clk;
4249        struct clk **clkp;
4250
4251        /* This should not happen because it would mean we have drivers
4252         * passing around clk_hw pointers instead of having the caller use
4253         * proper clk_get() style APIs
4254         */
4255        WARN_ON_ONCE(dev != hw->core->dev);
4256
4257        clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
4258        if (!clkp)
4259                return ERR_PTR(-ENOMEM);
4260
4261        clk = clk_hw_get_clk(hw, con_id);
4262        if (!IS_ERR(clk)) {
4263                *clkp = clk;
4264                devres_add(dev, clkp);
4265        } else {
4266                devres_free(clkp);
4267        }
4268
4269        return clk;
4270}
4271EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk);
4272
4273/*
4274 * clkdev helpers
4275 */
4276
4277void __clk_put(struct clk *clk)
4278{
4279        struct module *owner;
4280
4281        if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4282                return;
4283
4284        clk_prepare_lock();
4285
4286        /*
4287         * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
4288         * given user should be balanced with calls to clk_rate_exclusive_put()
4289         * and by that same consumer
4290         */
4291        if (WARN_ON(clk->exclusive_count)) {
4292                /* We voiced our concern, let's sanitize the situation */
4293                clk->core->protect_count -= (clk->exclusive_count - 1);
4294                clk_core_rate_unprotect(clk->core);
4295                clk->exclusive_count = 0;
4296        }
4297
4298        hlist_del(&clk->clks_node);
4299        if (clk->min_rate > clk->core->req_rate ||
4300            clk->max_rate < clk->core->req_rate)
4301                clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
4302
4303        owner = clk->core->owner;
4304        kref_put(&clk->core->ref, __clk_release);
4305
4306        clk_prepare_unlock();
4307
4308        module_put(owner);
4309
4310        free_clk(clk);
4311}
4312
4313/***        clk rate change notifiers        ***/
4314
4315/**
4316 * clk_notifier_register - add a clk rate change notifier
4317 * @clk: struct clk * to watch
4318 * @nb: struct notifier_block * with callback info
4319 *
4320 * Request notification when clk's rate changes.  This uses an SRCU
4321 * notifier because we want it to block and notifier unregistrations are
4322 * uncommon.  The callbacks associated with the notifier must not
4323 * re-enter into the clk framework by calling any top-level clk APIs;
4324 * this will cause a nested prepare_lock mutex.
4325 *
4326 * In all notification cases (pre, post and abort rate change) the original
4327 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
4328 * and the new frequency is passed via struct clk_notifier_data.new_rate.
4329 *
4330 * clk_notifier_register() must be called from non-atomic context.
4331 * Returns -EINVAL if called with null arguments, -ENOMEM upon
4332 * allocation failure; otherwise, passes along the return value of
4333 * srcu_notifier_chain_register().
4334 */
4335int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
4336{
4337        struct clk_notifier *cn;
4338        int ret = -ENOMEM;
4339
4340        if (!clk || !nb)
4341                return -EINVAL;
4342
4343        clk_prepare_lock();
4344
4345        /* search the list of notifiers for this clk */
4346        list_for_each_entry(cn, &clk_notifier_list, node)
4347                if (cn->clk == clk)
4348                        goto found;
4349
4350        /* if clk wasn't in the notifier list, allocate new clk_notifier */
4351        cn = kzalloc(sizeof(*cn), GFP_KERNEL);
4352        if (!cn)
4353                goto out;
4354
4355        cn->clk = clk;
4356        srcu_init_notifier_head(&cn->notifier_head);
4357
4358        list_add(&cn->node, &clk_notifier_list);
4359
4360found:
4361        ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
4362
4363        clk->core->notifier_count++;
4364
4365out:
4366        clk_prepare_unlock();
4367
4368        return ret;
4369}
4370EXPORT_SYMBOL_GPL(clk_notifier_register);
4371
4372/**
4373 * clk_notifier_unregister - remove a clk rate change notifier
4374 * @clk: struct clk *
4375 * @nb: struct notifier_block * with callback info
4376 *
4377 * Request no further notification for changes to 'clk' and frees memory
4378 * allocated in clk_notifier_register.
4379 *
4380 * Returns -EINVAL if called with null arguments; otherwise, passes
4381 * along the return value of srcu_notifier_chain_unregister().
4382 */
4383int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
4384{
4385        struct clk_notifier *cn;
4386        int ret = -ENOENT;
4387
4388        if (!clk || !nb)
4389                return -EINVAL;
4390
4391        clk_prepare_lock();
4392
4393        list_for_each_entry(cn, &clk_notifier_list, node) {
4394                if (cn->clk == clk) {
4395                        ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
4396
4397                        clk->core->notifier_count--;
4398
4399                        /* XXX the notifier code should handle this better */
4400                        if (!cn->notifier_head.head) {
4401                                srcu_cleanup_notifier_head(&cn->notifier_head);
4402                                list_del(&cn->node);
4403                                kfree(cn);
4404                        }
4405                        break;
4406                }
4407        }
4408
4409        clk_prepare_unlock();
4410
4411        return ret;
4412}
4413EXPORT_SYMBOL_GPL(clk_notifier_unregister);
4414
4415struct clk_notifier_devres {
4416        struct clk *clk;
4417        struct notifier_block *nb;
4418};
4419
4420static void devm_clk_notifier_release(struct device *dev, void *res)
4421{
4422        struct clk_notifier_devres *devres = res;
4423
4424        clk_notifier_unregister(devres->clk, devres->nb);
4425}
4426
4427int devm_clk_notifier_register(struct device *dev, struct clk *clk,
4428                               struct notifier_block *nb)
4429{
4430        struct clk_notifier_devres *devres;
4431        int ret;
4432
4433        devres = devres_alloc(devm_clk_notifier_release,
4434                              sizeof(*devres), GFP_KERNEL);
4435
4436        if (!devres)
4437                return -ENOMEM;
4438
4439        ret = clk_notifier_register(clk, nb);
4440        if (!ret) {
4441                devres->clk = clk;
4442                devres->nb = nb;
4443        } else {
4444                devres_free(devres);
4445        }
4446
4447        return ret;
4448}
4449EXPORT_SYMBOL_GPL(devm_clk_notifier_register);
4450
4451#ifdef CONFIG_OF
4452static void clk_core_reparent_orphans(void)
4453{
4454        clk_prepare_lock();
4455        clk_core_reparent_orphans_nolock();
4456        clk_prepare_unlock();
4457}
4458
4459/**
4460 * struct of_clk_provider - Clock provider registration structure
4461 * @link: Entry in global list of clock providers
4462 * @node: Pointer to device tree node of clock provider
4463 * @get: Get clock callback.  Returns NULL or a struct clk for the
4464 *       given clock specifier
4465 * @get_hw: Get clk_hw callback.  Returns NULL, ERR_PTR or a
4466 *       struct clk_hw for the given clock specifier
4467 * @data: context pointer to be passed into @get callback
4468 */
4469struct of_clk_provider {
4470        struct list_head link;
4471
4472        struct device_node *node;
4473        struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
4474        struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
4475        void *data;
4476};
4477
4478extern struct of_device_id __clk_of_table;
4479static const struct of_device_id __clk_of_table_sentinel
4480        __used __section("__clk_of_table_end");
4481
4482static LIST_HEAD(of_clk_providers);
4483static DEFINE_MUTEX(of_clk_mutex);
4484
4485struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
4486                                     void *data)
4487{
4488        return data;
4489}
4490EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
4491
4492struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
4493{
4494        return data;
4495}
4496EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
4497
4498struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
4499{
4500        struct clk_onecell_data *clk_data = data;
4501        unsigned int idx = clkspec->args[0];
4502
4503        if (idx >= clk_data->clk_num) {
4504                pr_err("%s: invalid clock index %u\n", __func__, idx);
4505                return ERR_PTR(-EINVAL);
4506        }
4507
4508        return clk_data->clks[idx];
4509}
4510EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
4511
4512struct clk_hw *
4513of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
4514{
4515        struct clk_hw_onecell_data *hw_data = data;
4516        unsigned int idx = clkspec->args[0];
4517
4518        if (idx >= hw_data->num) {
4519                pr_err("%s: invalid index %u\n", __func__, idx);
4520                return ERR_PTR(-EINVAL);
4521        }
4522
4523        return hw_data->hws[idx];
4524}
4525EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
4526
4527/**
4528 * of_clk_add_provider() - Register a clock provider for a node
4529 * @np: Device node pointer associated with clock provider
4530 * @clk_src_get: callback for decoding clock
4531 * @data: context pointer for @clk_src_get callback.
4532 *
4533 * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
4534 */
4535int of_clk_add_provider(struct device_node *np,
4536                        struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
4537                                                   void *data),
4538                        void *data)
4539{
4540        struct of_clk_provider *cp;
4541        int ret;
4542
4543        if (!np)
4544                return 0;
4545
4546        cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4547        if (!cp)
4548                return -ENOMEM;
4549
4550        cp->node = of_node_get(np);
4551        cp->data = data;
4552        cp->get = clk_src_get;
4553
4554        mutex_lock(&of_clk_mutex);
4555        list_add(&cp->link, &of_clk_providers);
4556        mutex_unlock(&of_clk_mutex);
4557        pr_debug("Added clock from %pOF\n", np);
4558
4559        clk_core_reparent_orphans();
4560
4561        ret = of_clk_set_defaults(np, true);
4562        if (ret < 0)
4563                of_clk_del_provider(np);
4564
4565        fwnode_dev_initialized(&np->fwnode, true);
4566
4567        return ret;
4568}
4569EXPORT_SYMBOL_GPL(of_clk_add_provider);
4570
4571/**
4572 * of_clk_add_hw_provider() - Register a clock provider for a node
4573 * @np: Device node pointer associated with clock provider
4574 * @get: callback for decoding clk_hw
4575 * @data: context pointer for @get callback.
4576 */
4577int of_clk_add_hw_provider(struct device_node *np,
4578                           struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4579                                                 void *data),
4580                           void *data)
4581{
4582        struct of_clk_provider *cp;
4583        int ret;
4584
4585        if (!np)
4586                return 0;
4587
4588        cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4589        if (!cp)
4590                return -ENOMEM;
4591
4592        cp->node = of_node_get(np);
4593        cp->data = data;
4594        cp->get_hw = get;
4595
4596        mutex_lock(&of_clk_mutex);
4597        list_add(&cp->link, &of_clk_providers);
4598        mutex_unlock(&of_clk_mutex);
4599        pr_debug("Added clk_hw provider from %pOF\n", np);
4600
4601        clk_core_reparent_orphans();
4602
4603        ret = of_clk_set_defaults(np, true);
4604        if (ret < 0)
4605                of_clk_del_provider(np);
4606
4607        fwnode_dev_initialized(&np->fwnode, true);
4608
4609        return ret;
4610}
4611EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
4612
4613static void devm_of_clk_release_provider(struct device *dev, void *res)
4614{
4615        of_clk_del_provider(*(struct device_node **)res);
4616}
4617
4618/*
4619 * We allow a child device to use its parent device as the clock provider node
4620 * for cases like MFD sub-devices where the child device driver wants to use
4621 * devm_*() APIs but not list the device in DT as a sub-node.
4622 */
4623static struct device_node *get_clk_provider_node(struct device *dev)
4624{
4625        struct device_node *np, *parent_np;
4626
4627        np = dev->of_node;
4628        parent_np = dev->parent ? dev->parent->of_node : NULL;
4629
4630        if (!of_find_property(np, "#clock-cells", NULL))
4631                if (of_find_property(parent_np, "#clock-cells", NULL))
4632                        np = parent_np;
4633
4634        return np;
4635}
4636
4637/**
4638 * devm_of_clk_add_hw_provider() - Managed clk provider node registration
4639 * @dev: Device acting as the clock provider (used for DT node and lifetime)
4640 * @get: callback for decoding clk_hw
4641 * @data: context pointer for @get callback
4642 *
4643 * Registers clock provider for given device's node. If the device has no DT
4644 * node or if the device node lacks of clock provider information (#clock-cells)
4645 * then the parent device's node is scanned for this information. If parent node
4646 * has the #clock-cells then it is used in registration. Provider is
4647 * automatically released at device exit.
4648 *
4649 * Return: 0 on success or an errno on failure.
4650 */
4651int devm_of_clk_add_hw_provider(struct device *dev,
4652                        struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4653                                              void *data),
4654                        void *data)
4655{
4656        struct device_node **ptr, *np;
4657        int ret;
4658
4659        ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
4660                           GFP_KERNEL);
4661        if (!ptr)
4662                return -ENOMEM;
4663
4664        np = get_clk_provider_node(dev);
4665        ret = of_clk_add_hw_provider(np, get, data);
4666        if (!ret) {
4667                *ptr = np;
4668                devres_add(dev, ptr);
4669        } else {
4670                devres_free(ptr);
4671        }
4672
4673        return ret;
4674}
4675EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
4676
4677/**
4678 * of_clk_del_provider() - Remove a previously registered clock provider
4679 * @np: Device node pointer associated with clock provider
4680 */
4681void of_clk_del_provider(struct device_node *np)
4682{
4683        struct of_clk_provider *cp;
4684
4685        if (!np)
4686                return;
4687
4688        mutex_lock(&of_clk_mutex);
4689        list_for_each_entry(cp, &of_clk_providers, link) {
4690                if (cp->node == np) {
4691                        list_del(&cp->link);
4692                        fwnode_dev_initialized(&np->fwnode, false);
4693                        of_node_put(cp->node);
4694                        kfree(cp);
4695                        break;
4696                }
4697        }
4698        mutex_unlock(&of_clk_mutex);
4699}
4700EXPORT_SYMBOL_GPL(of_clk_del_provider);
4701
4702static int devm_clk_provider_match(struct device *dev, void *res, void *data)
4703{
4704        struct device_node **np = res;
4705
4706        if (WARN_ON(!np || !*np))
4707                return 0;
4708
4709        return *np == data;
4710}
4711
4712/**
4713 * devm_of_clk_del_provider() - Remove clock provider registered using devm
4714 * @dev: Device to whose lifetime the clock provider was bound
4715 */
4716void devm_of_clk_del_provider(struct device *dev)
4717{
4718        int ret;
4719        struct device_node *np = get_clk_provider_node(dev);
4720
4721        ret = devres_release(dev, devm_of_clk_release_provider,
4722                             devm_clk_provider_match, np);
4723
4724        WARN_ON(ret);
4725}
4726EXPORT_SYMBOL(devm_of_clk_del_provider);
4727
4728/**
4729 * of_parse_clkspec() - Parse a DT clock specifier for a given device node
4730 * @np: device node to parse clock specifier from
4731 * @index: index of phandle to parse clock out of. If index < 0, @name is used
4732 * @name: clock name to find and parse. If name is NULL, the index is used
4733 * @out_args: Result of parsing the clock specifier
4734 *
4735 * Parses a device node's "clocks" and "clock-names" properties to find the
4736 * phandle and cells for the index or name that is desired. The resulting clock
4737 * specifier is placed into @out_args, or an errno is returned when there's a
4738 * parsing error. The @index argument is ignored if @name is non-NULL.
4739 *
4740 * Example:
4741 *
4742 * phandle1: clock-controller@1 {
4743 *      #clock-cells = <2>;
4744 * }
4745 *
4746 * phandle2: clock-controller@2 {
4747 *      #clock-cells = <1>;
4748 * }
4749 *
4750 * clock-consumer@3 {
4751 *      clocks = <&phandle1 1 2 &phandle2 3>;
4752 *      clock-names = "name1", "name2";
4753 * }
4754 *
4755 * To get a device_node for `clock-controller@2' node you may call this
4756 * function a few different ways:
4757 *
4758 *   of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
4759 *   of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
4760 *   of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
4761 *
4762 * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
4763 * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
4764 * the "clock-names" property of @np.
4765 */
4766static int of_parse_clkspec(const struct device_node *np, int index,
4767                            const char *name, struct of_phandle_args *out_args)
4768{
4769        int ret = -ENOENT;
4770
4771        /* Walk up the tree of devices looking for a clock property that matches */
4772        while (np) {
4773                /*
4774                 * For named clocks, first look up the name in the
4775                 * "clock-names" property.  If it cannot be found, then index
4776                 * will be an error code and of_parse_phandle_with_args() will
4777                 * return -EINVAL.
4778                 */
4779                if (name)
4780                        index = of_property_match_string(np, "clock-names", name);
4781                ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
4782                                                 index, out_args);
4783                if (!ret)
4784                        break;
4785                if (name && index >= 0)
4786                        break;
4787
4788                /*
4789                 * No matching clock found on this node.  If the parent node
4790                 * has a "clock-ranges" property, then we can try one of its
4791                 * clocks.
4792                 */
4793                np = np->parent;
4794                if (np && !of_get_property(np, "clock-ranges", NULL))
4795                        break;
4796                index = 0;
4797        }
4798
4799        return ret;
4800}
4801
4802static struct clk_hw *
4803__of_clk_get_hw_from_provider(struct of_clk_provider *provider,
4804                              struct of_phandle_args *clkspec)
4805{
4806        struct clk *clk;
4807
4808        if (provider->get_hw)
4809                return provider->get_hw(clkspec, provider->data);
4810
4811        clk = provider->get(clkspec, provider->data);
4812        if (IS_ERR(clk))
4813                return ERR_CAST(clk);
4814        return __clk_get_hw(clk);
4815}
4816
4817static struct clk_hw *
4818of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
4819{
4820        struct of_clk_provider *provider;
4821        struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
4822
4823        if (!clkspec)
4824                return ERR_PTR(-EINVAL);
4825
4826        mutex_lock(&of_clk_mutex);
4827        list_for_each_entry(provider, &of_clk_providers, link) {
4828                if (provider->node == clkspec->np) {
4829                        hw = __of_clk_get_hw_from_provider(provider, clkspec);
4830                        if (!IS_ERR(hw))
4831                                break;
4832                }
4833        }
4834        mutex_unlock(&of_clk_mutex);
4835
4836        return hw;
4837}
4838
4839/**
4840 * of_clk_get_from_provider() - Lookup a clock from a clock provider
4841 * @clkspec: pointer to a clock specifier data structure
4842 *
4843 * This function looks up a struct clk from the registered list of clock
4844 * providers, an input is a clock specifier data structure as returned
4845 * from the of_parse_phandle_with_args() function call.
4846 */
4847struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
4848{
4849        struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
4850
4851        return clk_hw_create_clk(NULL, hw, NULL, __func__);
4852}
4853EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
4854
4855struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
4856                             const char *con_id)
4857{
4858        int ret;
4859        struct clk_hw *hw;
4860        struct of_phandle_args clkspec;
4861
4862        ret = of_parse_clkspec(np, index, con_id, &clkspec);
4863        if (ret)
4864                return ERR_PTR(ret);
4865
4866        hw = of_clk_get_hw_from_clkspec(&clkspec);
4867        of_node_put(clkspec.np);
4868
4869        return hw;
4870}
4871
4872static struct clk *__of_clk_get(struct device_node *np,
4873                                int index, const char *dev_id,
4874                                const char *con_id)
4875{
4876        struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
4877
4878        return clk_hw_create_clk(NULL, hw, dev_id, con_id);
4879}
4880
4881struct clk *of_clk_get(struct device_node *np, int index)
4882{
4883        return __of_clk_get(np, index, np->full_name, NULL);
4884}
4885EXPORT_SYMBOL(of_clk_get);
4886
4887/**
4888 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
4889 * @np: pointer to clock consumer node
4890 * @name: name of consumer's clock input, or NULL for the first clock reference
4891 *
4892 * This function parses the clocks and clock-names properties,
4893 * and uses them to look up the struct clk from the registered list of clock
4894 * providers.
4895 */
4896struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
4897{
4898        if (!np)
4899                return ERR_PTR(-ENOENT);
4900
4901        return __of_clk_get(np, 0, np->full_name, name);
4902}
4903EXPORT_SYMBOL(of_clk_get_by_name);
4904
4905/**
4906 * of_clk_get_parent_count() - Count the number of clocks a device node has
4907 * @np: device node to count
4908 *
4909 * Returns: The number of clocks that are possible parents of this node
4910 */
4911unsigned int of_clk_get_parent_count(const struct device_node *np)
4912{
4913        int count;
4914
4915        count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
4916        if (count < 0)
4917                return 0;
4918
4919        return count;
4920}
4921EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
4922
4923const char *of_clk_get_parent_name(const struct device_node *np, int index)
4924{
4925        struct of_phandle_args clkspec;
4926        struct property *prop;
4927        const char *clk_name;
4928        const __be32 *vp;
4929        u32 pv;
4930        int rc;
4931        int count;
4932        struct clk *clk;
4933
4934        rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
4935                                        &clkspec);
4936        if (rc)
4937                return NULL;
4938
4939        index = clkspec.args_count ? clkspec.args[0] : 0;
4940        count = 0;
4941
4942        /* if there is an indices property, use it to transfer the index
4943         * specified into an array offset for the clock-output-names property.
4944         */
4945        of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
4946                if (index == pv) {
4947                        index = count;
4948                        break;
4949                }
4950                count++;
4951        }
4952        /* We went off the end of 'clock-indices' without finding it */
4953        if (prop && !vp)
4954                return NULL;
4955
4956        if (of_property_read_string_index(clkspec.np, "clock-output-names",
4957                                          index,
4958                                          &clk_name) < 0) {
4959                /*
4960                 * Best effort to get the name if the clock has been
4961                 * registered with the framework. If the clock isn't
4962                 * registered, we return the node name as the name of
4963                 * the clock as long as #clock-cells = 0.
4964                 */
4965                clk = of_clk_get_from_provider(&clkspec);
4966                if (IS_ERR(clk)) {
4967                        if (clkspec.args_count == 0)
4968                                clk_name = clkspec.np->name;
4969                        else
4970                                clk_name = NULL;
4971                } else {
4972                        clk_name = __clk_get_name(clk);
4973                        clk_put(clk);
4974                }
4975        }
4976
4977
4978        of_node_put(clkspec.np);
4979        return clk_name;
4980}
4981EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
4982
4983/**
4984 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
4985 * number of parents
4986 * @np: Device node pointer associated with clock provider
4987 * @parents: pointer to char array that hold the parents' names
4988 * @size: size of the @parents array
4989 *
4990 * Return: number of parents for the clock node.
4991 */
4992int of_clk_parent_fill(struct device_node *np, const char **parents,
4993                       unsigned int size)
4994{
4995        unsigned int i = 0;
4996
4997        while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
4998                i++;
4999
5000        return i;
5001}
5002EXPORT_SYMBOL_GPL(of_clk_parent_fill);
5003
5004struct clock_provider {
5005        void (*clk_init_cb)(struct device_node *);
5006        struct device_node *np;
5007        struct list_head node;
5008};
5009
5010/*
5011 * This function looks for a parent clock. If there is one, then it
5012 * checks that the provider for this parent clock was initialized, in
5013 * this case the parent clock will be ready.
5014 */
5015static int parent_ready(struct device_node *np)
5016{
5017        int i = 0;
5018
5019        while (true) {
5020                struct clk *clk = of_clk_get(np, i);
5021
5022                /* this parent is ready we can check the next one */
5023                if (!IS_ERR(clk)) {
5024                        clk_put(clk);
5025                        i++;
5026                        continue;
5027                }
5028
5029                /* at least one parent is not ready, we exit now */
5030                if (PTR_ERR(clk) == -EPROBE_DEFER)
5031                        return 0;
5032
5033                /*
5034                 * Here we make assumption that the device tree is
5035                 * written correctly. So an error means that there is
5036                 * no more parent. As we didn't exit yet, then the
5037                 * previous parent are ready. If there is no clock
5038                 * parent, no need to wait for them, then we can
5039                 * consider their absence as being ready
5040                 */
5041                return 1;
5042        }
5043}
5044
5045/**
5046 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
5047 * @np: Device node pointer associated with clock provider
5048 * @index: clock index
5049 * @flags: pointer to top-level framework flags
5050 *
5051 * Detects if the clock-critical property exists and, if so, sets the
5052 * corresponding CLK_IS_CRITICAL flag.
5053 *
5054 * Do not use this function. It exists only for legacy Device Tree
5055 * bindings, such as the one-clock-per-node style that are outdated.
5056 * Those bindings typically put all clock data into .dts and the Linux
5057 * driver has no clock data, thus making it impossible to set this flag
5058 * correctly from the driver. Only those drivers may call
5059 * of_clk_detect_critical from their setup functions.
5060 *
5061 * Return: error code or zero on success
5062 */
5063int of_clk_detect_critical(struct device_node *np, int index,
5064                           unsigned long *flags)
5065{
5066        struct property *prop;
5067        const __be32 *cur;
5068        uint32_t idx;
5069
5070        if (!np || !flags)
5071                return -EINVAL;
5072
5073        of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
5074                if (index == idx)
5075                        *flags |= CLK_IS_CRITICAL;
5076
5077        return 0;
5078}
5079
5080/**
5081 * of_clk_init() - Scan and init clock providers from the DT
5082 * @matches: array of compatible values and init functions for providers.
5083 *
5084 * This function scans the device tree for matching clock providers
5085 * and calls their initialization functions. It also does it by trying
5086 * to follow the dependencies.
5087 */
5088void __init of_clk_init(const struct of_device_id *matches)
5089{
5090        const struct of_device_id *match;
5091        struct device_node *np;
5092        struct clock_provider *