linux/arch/powerpc/platforms/83xx/suspend.c
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   1/*
   2 * MPC83xx suspend support
   3 *
   4 * Author: Scott Wood <scottwood@freescale.com>
   5 *
   6 * Copyright (c) 2006-2007 Freescale Semiconductor, Inc.
   7 *
   8 * This program is free software; you can redistribute it and/or modify it
   9 * under the terms of the GNU General Public License version 2 as published
  10 * by the Free Software Foundation.
  11 */
  12
  13#include <linux/init.h>
  14#include <linux/pm.h>
  15#include <linux/types.h>
  16#include <linux/ioport.h>
  17#include <linux/interrupt.h>
  18#include <linux/wait.h>
  19#include <linux/kthread.h>
  20#include <linux/freezer.h>
  21#include <linux/suspend.h>
  22#include <linux/fsl_devices.h>
  23#include <linux/of_platform.h>
  24#include <linux/export.h>
  25
  26#include <asm/reg.h>
  27#include <asm/io.h>
  28#include <asm/time.h>
  29#include <asm/mpc6xx.h>
  30
  31#include <sysdev/fsl_soc.h>
  32
  33#define PMCCR1_NEXT_STATE       0x0C /* Next state for power management */
  34#define PMCCR1_NEXT_STATE_SHIFT 2
  35#define PMCCR1_CURR_STATE       0x03 /* Current state for power management*/
  36#define IMMR_SYSCR_OFFSET       0x100
  37#define IMMR_RCW_OFFSET         0x900
  38#define RCW_PCI_HOST            0x80000000
  39
  40void mpc83xx_enter_deep_sleep(phys_addr_t immrbase);
  41
  42struct mpc83xx_pmc {
  43        u32 config;
  44#define PMCCR_DLPEN 2 /* DDR SDRAM low power enable */
  45#define PMCCR_SLPEN 1 /* System low power enable */
  46
  47        u32 event;
  48        u32 mask;
  49/* All but PMCI are deep-sleep only */
  50#define PMCER_GPIO   0x100
  51#define PMCER_PCI    0x080
  52#define PMCER_USB    0x040
  53#define PMCER_ETSEC1 0x020
  54#define PMCER_ETSEC2 0x010
  55#define PMCER_TIMER  0x008
  56#define PMCER_INT1   0x004
  57#define PMCER_INT2   0x002
  58#define PMCER_PMCI   0x001
  59#define PMCER_ALL    0x1FF
  60
  61        /* deep-sleep only */
  62        u32 config1;
  63#define PMCCR1_USE_STATE  0x80000000
  64#define PMCCR1_PME_EN     0x00000080
  65#define PMCCR1_ASSERT_PME 0x00000040
  66#define PMCCR1_POWER_OFF  0x00000020
  67
  68        /* deep-sleep only */
  69        u32 config2;
  70};
  71
  72struct mpc83xx_rcw {
  73        u32 rcwlr;
  74        u32 rcwhr;
  75};
  76
  77struct mpc83xx_clock {
  78        u32 spmr;
  79        u32 occr;
  80        u32 sccr;
  81};
  82
  83struct mpc83xx_syscr {
  84        __be32 sgprl;
  85        __be32 sgprh;
  86        __be32 spridr;
  87        __be32 :32;
  88        __be32 spcr;
  89        __be32 sicrl;
  90        __be32 sicrh;
  91};
  92
  93struct mpc83xx_saved {
  94        u32 sicrl;
  95        u32 sicrh;
  96        u32 sccr;
  97};
  98
  99struct pmc_type {
 100        int has_deep_sleep;
 101};
 102
 103static struct platform_device *pmc_dev;
 104static int has_deep_sleep, deep_sleeping;
 105static int pmc_irq;
 106static struct mpc83xx_pmc __iomem *pmc_regs;
 107static struct mpc83xx_clock __iomem *clock_regs;
 108static struct mpc83xx_syscr __iomem *syscr_regs;
 109static struct mpc83xx_saved saved_regs;
 110static int is_pci_agent, wake_from_pci;
 111static phys_addr_t immrbase;
 112static int pci_pm_state;
 113static DECLARE_WAIT_QUEUE_HEAD(agent_wq);
 114
 115int fsl_deep_sleep(void)
 116{
 117        return deep_sleeping;
 118}
 119EXPORT_SYMBOL(fsl_deep_sleep);
 120
 121static int mpc83xx_change_state(void)
 122{
 123        u32 curr_state;
 124        u32 reg_cfg1 = in_be32(&pmc_regs->config1);
 125
 126        if (is_pci_agent) {
 127                pci_pm_state = (reg_cfg1 & PMCCR1_NEXT_STATE) >>
 128                               PMCCR1_NEXT_STATE_SHIFT;
 129                curr_state = reg_cfg1 & PMCCR1_CURR_STATE;
 130
 131                if (curr_state != pci_pm_state) {
 132                        reg_cfg1 &= ~PMCCR1_CURR_STATE;
 133                        reg_cfg1 |= pci_pm_state;
 134                        out_be32(&pmc_regs->config1, reg_cfg1);
 135
 136                        wake_up(&agent_wq);
 137                        return 1;
 138                }
 139        }
 140
 141        return 0;
 142}
 143
 144static irqreturn_t pmc_irq_handler(int irq, void *dev_id)
 145{
 146        u32 event = in_be32(&pmc_regs->event);
 147        int ret = IRQ_NONE;
 148
 149        if (mpc83xx_change_state())
 150                ret = IRQ_HANDLED;
 151
 152        if (event) {
 153                out_be32(&pmc_regs->event, event);
 154                ret = IRQ_HANDLED;
 155        }
 156
 157        return ret;
 158}
 159
 160static void mpc83xx_suspend_restore_regs(void)
 161{
 162        out_be32(&syscr_regs->sicrl, saved_regs.sicrl);
 163        out_be32(&syscr_regs->sicrh, saved_regs.sicrh);
 164        out_be32(&clock_regs->sccr, saved_regs.sccr);
 165}
 166
 167static void mpc83xx_suspend_save_regs(void)
 168{
 169        saved_regs.sicrl = in_be32(&syscr_regs->sicrl);
 170        saved_regs.sicrh = in_be32(&syscr_regs->sicrh);
 171        saved_regs.sccr = in_be32(&clock_regs->sccr);
 172}
 173
 174static int mpc83xx_suspend_enter(suspend_state_t state)
 175{
 176        int ret = -EAGAIN;
 177
 178        /* Don't go to sleep if there's a race where pci_pm_state changes
 179         * between the agent thread checking it and the PM code disabling
 180         * interrupts.
 181         */
 182        if (wake_from_pci) {
 183                if (pci_pm_state != (deep_sleeping ? 3 : 2))
 184                        goto out;
 185
 186                out_be32(&pmc_regs->config1,
 187                         in_be32(&pmc_regs->config1) | PMCCR1_PME_EN);
 188        }
 189
 190        /* Put the system into low-power mode and the RAM
 191         * into self-refresh mode once the core goes to
 192         * sleep.
 193         */
 194
 195        out_be32(&pmc_regs->config, PMCCR_SLPEN | PMCCR_DLPEN);
 196
 197        /* If it has deep sleep (i.e. it's an 831x or compatible),
 198         * disable power to the core upon entering sleep mode.  This will
 199         * require going through the boot firmware upon a wakeup event.
 200         */
 201
 202        if (deep_sleeping) {
 203                mpc83xx_suspend_save_regs();
 204
 205                out_be32(&pmc_regs->mask, PMCER_ALL);
 206
 207                out_be32(&pmc_regs->config1,
 208                         in_be32(&pmc_regs->config1) | PMCCR1_POWER_OFF);
 209
 210                enable_kernel_fp();
 211
 212                mpc83xx_enter_deep_sleep(immrbase);
 213
 214                out_be32(&pmc_regs->config1,
 215                         in_be32(&pmc_regs->config1) & ~PMCCR1_POWER_OFF);
 216
 217                out_be32(&pmc_regs->mask, PMCER_PMCI);
 218
 219                mpc83xx_suspend_restore_regs();
 220        } else {
 221                out_be32(&pmc_regs->mask, PMCER_PMCI);
 222
 223                mpc6xx_enter_standby();
 224        }
 225
 226        ret = 0;
 227
 228out:
 229        out_be32(&pmc_regs->config1,
 230                 in_be32(&pmc_regs->config1) & ~PMCCR1_PME_EN);
 231
 232        return ret;
 233}
 234
 235static void mpc83xx_suspend_end(void)
 236{
 237        deep_sleeping = 0;
 238}
 239
 240static int mpc83xx_suspend_valid(suspend_state_t state)
 241{
 242        return state == PM_SUSPEND_STANDBY || state == PM_SUSPEND_MEM;
 243}
 244
 245static int mpc83xx_suspend_begin(suspend_state_t state)
 246{
 247        switch (state) {
 248                case PM_SUSPEND_STANDBY:
 249                        deep_sleeping = 0;
 250                        return 0;
 251
 252                case PM_SUSPEND_MEM:
 253                        if (has_deep_sleep)
 254                                deep_sleeping = 1;
 255
 256                        return 0;
 257
 258                default:
 259                        return -EINVAL;
 260        }
 261}
 262
 263static int agent_thread_fn(void *data)
 264{
 265        while (1) {
 266                wait_event_interruptible(agent_wq, pci_pm_state >= 2);
 267                try_to_freeze();
 268
 269                if (signal_pending(current) || pci_pm_state < 2)
 270                        continue;
 271
 272                /* With a preemptible kernel (or SMP), this could race with
 273                 * a userspace-driven suspend request.  It's probably best
 274                 * to avoid mixing the two with such a configuration (or
 275                 * else fix it by adding a mutex to state_store that we can
 276                 * synchronize with).
 277                 */
 278
 279                wake_from_pci = 1;
 280
 281                pm_suspend(pci_pm_state == 3 ? PM_SUSPEND_MEM :
 282                                               PM_SUSPEND_STANDBY);
 283
 284                wake_from_pci = 0;
 285        }
 286
 287        return 0;
 288}
 289
 290static void mpc83xx_set_agent(void)
 291{
 292        out_be32(&pmc_regs->config1, PMCCR1_USE_STATE);
 293        out_be32(&pmc_regs->mask, PMCER_PMCI);
 294
 295        kthread_run(agent_thread_fn, NULL, "PCI power mgt");
 296}
 297
 298static int mpc83xx_is_pci_agent(void)
 299{
 300        struct mpc83xx_rcw __iomem *rcw_regs;
 301        int ret;
 302
 303        rcw_regs = ioremap(get_immrbase() + IMMR_RCW_OFFSET,
 304                           sizeof(struct mpc83xx_rcw));
 305
 306        if (!rcw_regs)
 307                return -ENOMEM;
 308
 309        ret = !(in_be32(&rcw_regs->rcwhr) & RCW_PCI_HOST);
 310
 311        iounmap(rcw_regs);
 312        return ret;
 313}
 314
 315static const struct platform_suspend_ops mpc83xx_suspend_ops = {
 316        .valid = mpc83xx_suspend_valid,
 317        .begin = mpc83xx_suspend_begin,
 318        .enter = mpc83xx_suspend_enter,
 319        .end = mpc83xx_suspend_end,
 320};
 321
 322static struct of_device_id pmc_match[];
 323static int pmc_probe(struct platform_device *ofdev)
 324{
 325        const struct of_device_id *match;
 326        struct device_node *np = ofdev->dev.of_node;
 327        struct resource res;
 328        struct pmc_type *type;
 329        int ret = 0;
 330
 331        match = of_match_device(pmc_match, &ofdev->dev);
 332        if (!match)
 333                return -EINVAL;
 334
 335        type = match->data;
 336
 337        if (!of_device_is_available(np))
 338                return -ENODEV;
 339
 340        has_deep_sleep = type->has_deep_sleep;
 341        immrbase = get_immrbase();
 342        pmc_dev = ofdev;
 343
 344        is_pci_agent = mpc83xx_is_pci_agent();
 345        if (is_pci_agent < 0)
 346                return is_pci_agent;
 347
 348        ret = of_address_to_resource(np, 0, &res);
 349        if (ret)
 350                return -ENODEV;
 351
 352        pmc_irq = irq_of_parse_and_map(np, 0);
 353        if (pmc_irq != NO_IRQ) {
 354                ret = request_irq(pmc_irq, pmc_irq_handler, IRQF_SHARED,
 355                                  "pmc", ofdev);
 356
 357                if (ret)
 358                        return -EBUSY;
 359        }
 360
 361        pmc_regs = ioremap(res.start, sizeof(struct mpc83xx_pmc));
 362
 363        if (!pmc_regs) {
 364                ret = -ENOMEM;
 365                goto out;
 366        }
 367
 368        ret = of_address_to_resource(np, 1, &res);
 369        if (ret) {
 370                ret = -ENODEV;
 371                goto out_pmc;
 372        }
 373
 374        clock_regs = ioremap(res.start, sizeof(struct mpc83xx_pmc));
 375
 376        if (!clock_regs) {
 377                ret = -ENOMEM;
 378                goto out_pmc;
 379        }
 380
 381        if (has_deep_sleep) {
 382                syscr_regs = ioremap(immrbase + IMMR_SYSCR_OFFSET,
 383                                     sizeof(*syscr_regs));
 384                if (!syscr_regs) {
 385                        ret = -ENOMEM;
 386                        goto out_syscr;
 387                }
 388        }
 389
 390        if (is_pci_agent)
 391                mpc83xx_set_agent();
 392
 393        suspend_set_ops(&mpc83xx_suspend_ops);
 394        return 0;
 395
 396out_syscr:
 397        iounmap(clock_regs);
 398out_pmc:
 399        iounmap(pmc_regs);
 400out:
 401        if (pmc_irq != NO_IRQ)
 402                free_irq(pmc_irq, ofdev);
 403
 404        return ret;
 405}
 406
 407static int pmc_remove(struct platform_device *ofdev)
 408{
 409        return -EPERM;
 410};
 411
 412static struct pmc_type pmc_types[] = {
 413        {
 414                .has_deep_sleep = 1,
 415        },
 416        {
 417                .has_deep_sleep = 0,
 418        }
 419};
 420
 421static struct of_device_id pmc_match[] = {
 422        {
 423                .compatible = "fsl,mpc8313-pmc",
 424                .data = &pmc_types[0],
 425        },
 426        {
 427                .compatible = "fsl,mpc8349-pmc",
 428                .data = &pmc_types[1],
 429        },
 430        {}
 431};
 432
 433static struct platform_driver pmc_driver = {
 434        .driver = {
 435                .name = "mpc83xx-pmc",
 436                .owner = THIS_MODULE,
 437                .of_match_table = pmc_match,
 438        },
 439        .probe = pmc_probe,
 440        .remove = pmc_remove
 441};
 442
 443static int pmc_init(void)
 444{
 445        return platform_driver_register(&pmc_driver);
 446}
 447
 448module_init(pmc_init);
 449