linux/drivers/dma/at_hdmac.c
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   1/*
   2 * Driver for the Atmel AHB DMA Controller (aka HDMA or DMAC on AT91 systems)
   3 *
   4 * Copyright (C) 2008 Atmel Corporation
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 *
  12 * This supports the Atmel AHB DMA Controller found in several Atmel SoCs.
  13 * The only Atmel DMA Controller that is not covered by this driver is the one
  14 * found on AT91SAM9263.
  15 */
  16
  17#include <linux/clk.h>
  18#include <linux/dmaengine.h>
  19#include <linux/dma-mapping.h>
  20#include <linux/dmapool.h>
  21#include <linux/interrupt.h>
  22#include <linux/module.h>
  23#include <linux/platform_device.h>
  24#include <linux/slab.h>
  25#include <linux/of.h>
  26#include <linux/of_device.h>
  27
  28#include "at_hdmac_regs.h"
  29#include "dmaengine.h"
  30
  31/*
  32 * Glossary
  33 * --------
  34 *
  35 * at_hdmac             : Name of the ATmel AHB DMA Controller
  36 * at_dma_ / atdma      : ATmel DMA controller entity related
  37 * atc_ / atchan        : ATmel DMA Channel entity related
  38 */
  39
  40#define ATC_DEFAULT_CFG         (ATC_FIFOCFG_HALFFIFO)
  41#define ATC_DEFAULT_CTRLB       (ATC_SIF(AT_DMA_MEM_IF) \
  42                                |ATC_DIF(AT_DMA_MEM_IF))
  43
  44/*
  45 * Initial number of descriptors to allocate for each channel. This could
  46 * be increased during dma usage.
  47 */
  48static unsigned int init_nr_desc_per_channel = 64;
  49module_param(init_nr_desc_per_channel, uint, 0644);
  50MODULE_PARM_DESC(init_nr_desc_per_channel,
  51                 "initial descriptors per channel (default: 64)");
  52
  53
  54/* prototypes */
  55static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx);
  56
  57
  58/*----------------------------------------------------------------------*/
  59
  60static struct at_desc *atc_first_active(struct at_dma_chan *atchan)
  61{
  62        return list_first_entry(&atchan->active_list,
  63                                struct at_desc, desc_node);
  64}
  65
  66static struct at_desc *atc_first_queued(struct at_dma_chan *atchan)
  67{
  68        return list_first_entry(&atchan->queue,
  69                                struct at_desc, desc_node);
  70}
  71
  72/**
  73 * atc_alloc_descriptor - allocate and return an initialized descriptor
  74 * @chan: the channel to allocate descriptors for
  75 * @gfp_flags: GFP allocation flags
  76 *
  77 * Note: The ack-bit is positioned in the descriptor flag at creation time
  78 *       to make initial allocation more convenient. This bit will be cleared
  79 *       and control will be given to client at usage time (during
  80 *       preparation functions).
  81 */
  82static struct at_desc *atc_alloc_descriptor(struct dma_chan *chan,
  83                                            gfp_t gfp_flags)
  84{
  85        struct at_desc  *desc = NULL;
  86        struct at_dma   *atdma = to_at_dma(chan->device);
  87        dma_addr_t phys;
  88
  89        desc = dma_pool_alloc(atdma->dma_desc_pool, gfp_flags, &phys);
  90        if (desc) {
  91                memset(desc, 0, sizeof(struct at_desc));
  92                INIT_LIST_HEAD(&desc->tx_list);
  93                dma_async_tx_descriptor_init(&desc->txd, chan);
  94                /* txd.flags will be overwritten in prep functions */
  95                desc->txd.flags = DMA_CTRL_ACK;
  96                desc->txd.tx_submit = atc_tx_submit;
  97                desc->txd.phys = phys;
  98        }
  99
 100        return desc;
 101}
 102
 103/**
 104 * atc_desc_get - get an unused descriptor from free_list
 105 * @atchan: channel we want a new descriptor for
 106 */
 107static struct at_desc *atc_desc_get(struct at_dma_chan *atchan)
 108{
 109        struct at_desc *desc, *_desc;
 110        struct at_desc *ret = NULL;
 111        unsigned long flags;
 112        unsigned int i = 0;
 113        LIST_HEAD(tmp_list);
 114
 115        spin_lock_irqsave(&atchan->lock, flags);
 116        list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) {
 117                i++;
 118                if (async_tx_test_ack(&desc->txd)) {
 119                        list_del(&desc->desc_node);
 120                        ret = desc;
 121                        break;
 122                }
 123                dev_dbg(chan2dev(&atchan->chan_common),
 124                                "desc %p not ACKed\n", desc);
 125        }
 126        spin_unlock_irqrestore(&atchan->lock, flags);
 127        dev_vdbg(chan2dev(&atchan->chan_common),
 128                "scanned %u descriptors on freelist\n", i);
 129
 130        /* no more descriptor available in initial pool: create one more */
 131        if (!ret) {
 132                ret = atc_alloc_descriptor(&atchan->chan_common, GFP_ATOMIC);
 133                if (ret) {
 134                        spin_lock_irqsave(&atchan->lock, flags);
 135                        atchan->descs_allocated++;
 136                        spin_unlock_irqrestore(&atchan->lock, flags);
 137                } else {
 138                        dev_err(chan2dev(&atchan->chan_common),
 139                                        "not enough descriptors available\n");
 140                }
 141        }
 142
 143        return ret;
 144}
 145
 146/**
 147 * atc_desc_put - move a descriptor, including any children, to the free list
 148 * @atchan: channel we work on
 149 * @desc: descriptor, at the head of a chain, to move to free list
 150 */
 151static void atc_desc_put(struct at_dma_chan *atchan, struct at_desc *desc)
 152{
 153        if (desc) {
 154                struct at_desc *child;
 155                unsigned long flags;
 156
 157                spin_lock_irqsave(&atchan->lock, flags);
 158                list_for_each_entry(child, &desc->tx_list, desc_node)
 159                        dev_vdbg(chan2dev(&atchan->chan_common),
 160                                        "moving child desc %p to freelist\n",
 161                                        child);
 162                list_splice_init(&desc->tx_list, &atchan->free_list);
 163                dev_vdbg(chan2dev(&atchan->chan_common),
 164                         "moving desc %p to freelist\n", desc);
 165                list_add(&desc->desc_node, &atchan->free_list);
 166                spin_unlock_irqrestore(&atchan->lock, flags);
 167        }
 168}
 169
 170/**
 171 * atc_desc_chain - build chain adding a descripor
 172 * @first: address of first descripor of the chain
 173 * @prev: address of previous descripor of the chain
 174 * @desc: descriptor to queue
 175 *
 176 * Called from prep_* functions
 177 */
 178static void atc_desc_chain(struct at_desc **first, struct at_desc **prev,
 179                           struct at_desc *desc)
 180{
 181        if (!(*first)) {
 182                *first = desc;
 183        } else {
 184                /* inform the HW lli about chaining */
 185                (*prev)->lli.dscr = desc->txd.phys;
 186                /* insert the link descriptor to the LD ring */
 187                list_add_tail(&desc->desc_node,
 188                                &(*first)->tx_list);
 189        }
 190        *prev = desc;
 191}
 192
 193/**
 194 * atc_dostart - starts the DMA engine for real
 195 * @atchan: the channel we want to start
 196 * @first: first descriptor in the list we want to begin with
 197 *
 198 * Called with atchan->lock held and bh disabled
 199 */
 200static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first)
 201{
 202        struct at_dma   *atdma = to_at_dma(atchan->chan_common.device);
 203
 204        /* ASSERT:  channel is idle */
 205        if (atc_chan_is_enabled(atchan)) {
 206                dev_err(chan2dev(&atchan->chan_common),
 207                        "BUG: Attempted to start non-idle channel\n");
 208                dev_err(chan2dev(&atchan->chan_common),
 209                        "  channel: s0x%x d0x%x ctrl0x%x:0x%x l0x%x\n",
 210                        channel_readl(atchan, SADDR),
 211                        channel_readl(atchan, DADDR),
 212                        channel_readl(atchan, CTRLA),
 213                        channel_readl(atchan, CTRLB),
 214                        channel_readl(atchan, DSCR));
 215
 216                /* The tasklet will hopefully advance the queue... */
 217                return;
 218        }
 219
 220        vdbg_dump_regs(atchan);
 221
 222        channel_writel(atchan, SADDR, 0);
 223        channel_writel(atchan, DADDR, 0);
 224        channel_writel(atchan, CTRLA, 0);
 225        channel_writel(atchan, CTRLB, 0);
 226        channel_writel(atchan, DSCR, first->txd.phys);
 227        dma_writel(atdma, CHER, atchan->mask);
 228
 229        vdbg_dump_regs(atchan);
 230}
 231
 232/**
 233 * atc_chain_complete - finish work for one transaction chain
 234 * @atchan: channel we work on
 235 * @desc: descriptor at the head of the chain we want do complete
 236 *
 237 * Called with atchan->lock held and bh disabled */
 238static void
 239atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
 240{
 241        struct dma_async_tx_descriptor  *txd = &desc->txd;
 242
 243        dev_vdbg(chan2dev(&atchan->chan_common),
 244                "descriptor %u complete\n", txd->cookie);
 245
 246        /* mark the descriptor as complete for non cyclic cases only */
 247        if (!atc_chan_is_cyclic(atchan))
 248                dma_cookie_complete(txd);
 249
 250        /* move children to free_list */
 251        list_splice_init(&desc->tx_list, &atchan->free_list);
 252        /* move myself to free_list */
 253        list_move(&desc->desc_node, &atchan->free_list);
 254
 255        /* unmap dma addresses (not on slave channels) */
 256        if (!atchan->chan_common.private) {
 257                struct device *parent = chan2parent(&atchan->chan_common);
 258                if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
 259                        if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
 260                                dma_unmap_single(parent,
 261                                                desc->lli.daddr,
 262                                                desc->len, DMA_FROM_DEVICE);
 263                        else
 264                                dma_unmap_page(parent,
 265                                                desc->lli.daddr,
 266                                                desc->len, DMA_FROM_DEVICE);
 267                }
 268                if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
 269                        if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
 270                                dma_unmap_single(parent,
 271                                                desc->lli.saddr,
 272                                                desc->len, DMA_TO_DEVICE);
 273                        else
 274                                dma_unmap_page(parent,
 275                                                desc->lli.saddr,
 276                                                desc->len, DMA_TO_DEVICE);
 277                }
 278        }
 279
 280        /* for cyclic transfers,
 281         * no need to replay callback function while stopping */
 282        if (!atc_chan_is_cyclic(atchan)) {
 283                dma_async_tx_callback   callback = txd->callback;
 284                void                    *param = txd->callback_param;
 285
 286                /*
 287                 * The API requires that no submissions are done from a
 288                 * callback, so we don't need to drop the lock here
 289                 */
 290                if (callback)
 291                        callback(param);
 292        }
 293
 294        dma_run_dependencies(txd);
 295}
 296
 297/**
 298 * atc_complete_all - finish work for all transactions
 299 * @atchan: channel to complete transactions for
 300 *
 301 * Eventually submit queued descriptors if any
 302 *
 303 * Assume channel is idle while calling this function
 304 * Called with atchan->lock held and bh disabled
 305 */
 306static void atc_complete_all(struct at_dma_chan *atchan)
 307{
 308        struct at_desc *desc, *_desc;
 309        LIST_HEAD(list);
 310
 311        dev_vdbg(chan2dev(&atchan->chan_common), "complete all\n");
 312
 313        BUG_ON(atc_chan_is_enabled(atchan));
 314
 315        /*
 316         * Submit queued descriptors ASAP, i.e. before we go through
 317         * the completed ones.
 318         */
 319        if (!list_empty(&atchan->queue))
 320                atc_dostart(atchan, atc_first_queued(atchan));
 321        /* empty active_list now it is completed */
 322        list_splice_init(&atchan->active_list, &list);
 323        /* empty queue list by moving descriptors (if any) to active_list */
 324        list_splice_init(&atchan->queue, &atchan->active_list);
 325
 326        list_for_each_entry_safe(desc, _desc, &list, desc_node)
 327                atc_chain_complete(atchan, desc);
 328}
 329
 330/**
 331 * atc_cleanup_descriptors - cleanup up finished descriptors in active_list
 332 * @atchan: channel to be cleaned up
 333 *
 334 * Called with atchan->lock held and bh disabled
 335 */
 336static void atc_cleanup_descriptors(struct at_dma_chan *atchan)
 337{
 338        struct at_desc  *desc, *_desc;
 339        struct at_desc  *child;
 340
 341        dev_vdbg(chan2dev(&atchan->chan_common), "cleanup descriptors\n");
 342
 343        list_for_each_entry_safe(desc, _desc, &atchan->active_list, desc_node) {
 344                if (!(desc->lli.ctrla & ATC_DONE))
 345                        /* This one is currently in progress */
 346                        return;
 347
 348                list_for_each_entry(child, &desc->tx_list, desc_node)
 349                        if (!(child->lli.ctrla & ATC_DONE))
 350                                /* Currently in progress */
 351                                return;
 352
 353                /*
 354                 * No descriptors so far seem to be in progress, i.e.
 355                 * this chain must be done.
 356                 */
 357                atc_chain_complete(atchan, desc);
 358        }
 359}
 360
 361/**
 362 * atc_advance_work - at the end of a transaction, move forward
 363 * @atchan: channel where the transaction ended
 364 *
 365 * Called with atchan->lock held and bh disabled
 366 */
 367static void atc_advance_work(struct at_dma_chan *atchan)
 368{
 369        dev_vdbg(chan2dev(&atchan->chan_common), "advance_work\n");
 370
 371        if (list_empty(&atchan->active_list) ||
 372            list_is_singular(&atchan->active_list)) {
 373                atc_complete_all(atchan);
 374        } else {
 375                atc_chain_complete(atchan, atc_first_active(atchan));
 376                /* advance work */
 377                atc_dostart(atchan, atc_first_active(atchan));
 378        }
 379}
 380
 381
 382/**
 383 * atc_handle_error - handle errors reported by DMA controller
 384 * @atchan: channel where error occurs
 385 *
 386 * Called with atchan->lock held and bh disabled
 387 */
 388static void atc_handle_error(struct at_dma_chan *atchan)
 389{
 390        struct at_desc *bad_desc;
 391        struct at_desc *child;
 392
 393        /*
 394         * The descriptor currently at the head of the active list is
 395         * broked. Since we don't have any way to report errors, we'll
 396         * just have to scream loudly and try to carry on.
 397         */
 398        bad_desc = atc_first_active(atchan);
 399        list_del_init(&bad_desc->desc_node);
 400
 401        /* As we are stopped, take advantage to push queued descriptors
 402         * in active_list */
 403        list_splice_init(&atchan->queue, atchan->active_list.prev);
 404
 405        /* Try to restart the controller */
 406        if (!list_empty(&atchan->active_list))
 407                atc_dostart(atchan, atc_first_active(atchan));
 408
 409        /*
 410         * KERN_CRITICAL may seem harsh, but since this only happens
 411         * when someone submits a bad physical address in a
 412         * descriptor, we should consider ourselves lucky that the
 413         * controller flagged an error instead of scribbling over
 414         * random memory locations.
 415         */
 416        dev_crit(chan2dev(&atchan->chan_common),
 417                        "Bad descriptor submitted for DMA!\n");
 418        dev_crit(chan2dev(&atchan->chan_common),
 419                        "  cookie: %d\n", bad_desc->txd.cookie);
 420        atc_dump_lli(atchan, &bad_desc->lli);
 421        list_for_each_entry(child, &bad_desc->tx_list, desc_node)
 422                atc_dump_lli(atchan, &child->lli);
 423
 424        /* Pretend the descriptor completed successfully */
 425        atc_chain_complete(atchan, bad_desc);
 426}
 427
 428/**
 429 * atc_handle_cyclic - at the end of a period, run callback function
 430 * @atchan: channel used for cyclic operations
 431 *
 432 * Called with atchan->lock held and bh disabled
 433 */
 434static void atc_handle_cyclic(struct at_dma_chan *atchan)
 435{
 436        struct at_desc                  *first = atc_first_active(atchan);
 437        struct dma_async_tx_descriptor  *txd = &first->txd;
 438        dma_async_tx_callback           callback = txd->callback;
 439        void                            *param = txd->callback_param;
 440
 441        dev_vdbg(chan2dev(&atchan->chan_common),
 442                        "new cyclic period llp 0x%08x\n",
 443                        channel_readl(atchan, DSCR));
 444
 445        if (callback)
 446                callback(param);
 447}
 448
 449/*--  IRQ & Tasklet  ---------------------------------------------------*/
 450
 451static void atc_tasklet(unsigned long data)
 452{
 453        struct at_dma_chan *atchan = (struct at_dma_chan *)data;
 454        unsigned long flags;
 455
 456        spin_lock_irqsave(&atchan->lock, flags);
 457        if (test_and_clear_bit(ATC_IS_ERROR, &atchan->status))
 458                atc_handle_error(atchan);
 459        else if (atc_chan_is_cyclic(atchan))
 460                atc_handle_cyclic(atchan);
 461        else
 462                atc_advance_work(atchan);
 463
 464        spin_unlock_irqrestore(&atchan->lock, flags);
 465}
 466
 467static irqreturn_t at_dma_interrupt(int irq, void *dev_id)
 468{
 469        struct at_dma           *atdma = (struct at_dma *)dev_id;
 470        struct at_dma_chan      *atchan;
 471        int                     i;
 472        u32                     status, pending, imr;
 473        int                     ret = IRQ_NONE;
 474
 475        do {
 476                imr = dma_readl(atdma, EBCIMR);
 477                status = dma_readl(atdma, EBCISR);
 478                pending = status & imr;
 479
 480                if (!pending)
 481                        break;
 482
 483                dev_vdbg(atdma->dma_common.dev,
 484                        "interrupt: status = 0x%08x, 0x%08x, 0x%08x\n",
 485                         status, imr, pending);
 486
 487                for (i = 0; i < atdma->dma_common.chancnt; i++) {
 488                        atchan = &atdma->chan[i];
 489                        if (pending & (AT_DMA_BTC(i) | AT_DMA_ERR(i))) {
 490                                if (pending & AT_DMA_ERR(i)) {
 491                                        /* Disable channel on AHB error */
 492                                        dma_writel(atdma, CHDR,
 493                                                AT_DMA_RES(i) | atchan->mask);
 494                                        /* Give information to tasklet */
 495                                        set_bit(ATC_IS_ERROR, &atchan->status);
 496                                }
 497                                tasklet_schedule(&atchan->tasklet);
 498                                ret = IRQ_HANDLED;
 499                        }
 500                }
 501
 502        } while (pending);
 503
 504        return ret;
 505}
 506
 507
 508/*--  DMA Engine API  --------------------------------------------------*/
 509
 510/**
 511 * atc_tx_submit - set the prepared descriptor(s) to be executed by the engine
 512 * @desc: descriptor at the head of the transaction chain
 513 *
 514 * Queue chain if DMA engine is working already
 515 *
 516 * Cookie increment and adding to active_list or queue must be atomic
 517 */
 518static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx)
 519{
 520        struct at_desc          *desc = txd_to_at_desc(tx);
 521        struct at_dma_chan      *atchan = to_at_dma_chan(tx->chan);
 522        dma_cookie_t            cookie;
 523        unsigned long           flags;
 524
 525        spin_lock_irqsave(&atchan->lock, flags);
 526        cookie = dma_cookie_assign(tx);
 527
 528        if (list_empty(&atchan->active_list)) {
 529                dev_vdbg(chan2dev(tx->chan), "tx_submit: started %u\n",
 530                                desc->txd.cookie);
 531                atc_dostart(atchan, desc);
 532                list_add_tail(&desc->desc_node, &atchan->active_list);
 533        } else {
 534                dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",
 535                                desc->txd.cookie);
 536                list_add_tail(&desc->desc_node, &atchan->queue);
 537        }
 538
 539        spin_unlock_irqrestore(&atchan->lock, flags);
 540
 541        return cookie;
 542}
 543
 544/**
 545 * atc_prep_dma_memcpy - prepare a memcpy operation
 546 * @chan: the channel to prepare operation on
 547 * @dest: operation virtual destination address
 548 * @src: operation virtual source address
 549 * @len: operation length
 550 * @flags: tx descriptor status flags
 551 */
 552static struct dma_async_tx_descriptor *
 553atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 554                size_t len, unsigned long flags)
 555{
 556        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
 557        struct at_desc          *desc = NULL;
 558        struct at_desc          *first = NULL;
 559        struct at_desc          *prev = NULL;
 560        size_t                  xfer_count;
 561        size_t                  offset;
 562        unsigned int            src_width;
 563        unsigned int            dst_width;
 564        u32                     ctrla;
 565        u32                     ctrlb;
 566
 567        dev_vdbg(chan2dev(chan), "prep_dma_memcpy: d0x%x s0x%x l0x%zx f0x%lx\n",
 568                        dest, src, len, flags);
 569
 570        if (unlikely(!len)) {
 571                dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
 572                return NULL;
 573        }
 574
 575        ctrlb =   ATC_DEFAULT_CTRLB | ATC_IEN
 576                | ATC_SRC_ADDR_MODE_INCR
 577                | ATC_DST_ADDR_MODE_INCR
 578                | ATC_FC_MEM2MEM;
 579
 580        /*
 581         * We can be a lot more clever here, but this should take care
 582         * of the most common optimization.
 583         */
 584        if (!((src | dest  | len) & 3)) {
 585                ctrla = ATC_SRC_WIDTH_WORD | ATC_DST_WIDTH_WORD;
 586                src_width = dst_width = 2;
 587        } else if (!((src | dest | len) & 1)) {
 588                ctrla = ATC_SRC_WIDTH_HALFWORD | ATC_DST_WIDTH_HALFWORD;
 589                src_width = dst_width = 1;
 590        } else {
 591                ctrla = ATC_SRC_WIDTH_BYTE | ATC_DST_WIDTH_BYTE;
 592                src_width = dst_width = 0;
 593        }
 594
 595        for (offset = 0; offset < len; offset += xfer_count << src_width) {
 596                xfer_count = min_t(size_t, (len - offset) >> src_width,
 597                                ATC_BTSIZE_MAX);
 598
 599                desc = atc_desc_get(atchan);
 600                if (!desc)
 601                        goto err_desc_get;
 602
 603                desc->lli.saddr = src + offset;
 604                desc->lli.daddr = dest + offset;
 605                desc->lli.ctrla = ctrla | xfer_count;
 606                desc->lli.ctrlb = ctrlb;
 607
 608                desc->txd.cookie = 0;
 609
 610                atc_desc_chain(&first, &prev, desc);
 611        }
 612
 613        /* First descriptor of the chain embedds additional information */
 614        first->txd.cookie = -EBUSY;
 615        first->len = len;
 616
 617        /* set end-of-link to the last link descriptor of list*/
 618        set_desc_eol(desc);
 619
 620        first->txd.flags = flags; /* client is in control of this ack */
 621
 622        return &first->txd;
 623
 624err_desc_get:
 625        atc_desc_put(atchan, first);
 626        return NULL;
 627}
 628
 629
 630/**
 631 * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
 632 * @chan: DMA channel
 633 * @sgl: scatterlist to transfer to/from
 634 * @sg_len: number of entries in @scatterlist
 635 * @direction: DMA direction
 636 * @flags: tx descriptor status flags
 637 * @context: transaction context (ignored)
 638 */
 639static struct dma_async_tx_descriptor *
 640atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 641                unsigned int sg_len, enum dma_transfer_direction direction,
 642                unsigned long flags, void *context)
 643{
 644        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
 645        struct at_dma_slave     *atslave = chan->private;
 646        struct dma_slave_config *sconfig = &atchan->dma_sconfig;
 647        struct at_desc          *first = NULL;
 648        struct at_desc          *prev = NULL;
 649        u32                     ctrla;
 650        u32                     ctrlb;
 651        dma_addr_t              reg;
 652        unsigned int            reg_width;
 653        unsigned int            mem_width;
 654        unsigned int            i;
 655        struct scatterlist      *sg;
 656        size_t                  total_len = 0;
 657
 658        dev_vdbg(chan2dev(chan), "prep_slave_sg (%d): %s f0x%lx\n",
 659                        sg_len,
 660                        direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE",
 661                        flags);
 662
 663        if (unlikely(!atslave || !sg_len)) {
 664                dev_dbg(chan2dev(chan), "prep_slave_sg: sg length is zero!\n");
 665                return NULL;
 666        }
 667
 668        ctrla =   ATC_SCSIZE(sconfig->src_maxburst)
 669                | ATC_DCSIZE(sconfig->dst_maxburst);
 670        ctrlb = ATC_IEN;
 671
 672        switch (direction) {
 673        case DMA_MEM_TO_DEV:
 674                reg_width = convert_buswidth(sconfig->dst_addr_width);
 675                ctrla |=  ATC_DST_WIDTH(reg_width);
 676                ctrlb |=  ATC_DST_ADDR_MODE_FIXED
 677                        | ATC_SRC_ADDR_MODE_INCR
 678                        | ATC_FC_MEM2PER
 679                        | ATC_SIF(AT_DMA_MEM_IF) | ATC_DIF(AT_DMA_PER_IF);
 680                reg = sconfig->dst_addr;
 681                for_each_sg(sgl, sg, sg_len, i) {
 682                        struct at_desc  *desc;
 683                        u32             len;
 684                        u32             mem;
 685
 686                        desc = atc_desc_get(atchan);
 687                        if (!desc)
 688                                goto err_desc_get;
 689
 690                        mem = sg_dma_address(sg);
 691                        len = sg_dma_len(sg);
 692                        if (unlikely(!len)) {
 693                                dev_dbg(chan2dev(chan),
 694                                        "prep_slave_sg: sg(%d) data length is zero\n", i);
 695                                goto err;
 696                        }
 697                        mem_width = 2;
 698                        if (unlikely(mem & 3 || len & 3))
 699                                mem_width = 0;
 700
 701                        desc->lli.saddr = mem;
 702                        desc->lli.daddr = reg;
 703                        desc->lli.ctrla = ctrla
 704                                        | ATC_SRC_WIDTH(mem_width)
 705                                        | len >> mem_width;
 706                        desc->lli.ctrlb = ctrlb;
 707
 708                        atc_desc_chain(&first, &prev, desc);
 709                        total_len += len;
 710                }
 711                break;
 712        case DMA_DEV_TO_MEM:
 713                reg_width = convert_buswidth(sconfig->src_addr_width);
 714                ctrla |=  ATC_SRC_WIDTH(reg_width);
 715                ctrlb |=  ATC_DST_ADDR_MODE_INCR
 716                        | ATC_SRC_ADDR_MODE_FIXED
 717                        | ATC_FC_PER2MEM
 718                        | ATC_SIF(AT_DMA_PER_IF) | ATC_DIF(AT_DMA_MEM_IF);
 719
 720                reg = sconfig->src_addr;
 721                for_each_sg(sgl, sg, sg_len, i) {
 722                        struct at_desc  *desc;
 723                        u32             len;
 724                        u32             mem;
 725
 726                        desc = atc_desc_get(atchan);
 727                        if (!desc)
 728                                goto err_desc_get;
 729
 730                        mem = sg_dma_address(sg);
 731                        len = sg_dma_len(sg);
 732                        if (unlikely(!len)) {
 733                                dev_dbg(chan2dev(chan),
 734                                        "prep_slave_sg: sg(%d) data length is zero\n", i);
 735                                goto err;
 736                        }
 737                        mem_width = 2;
 738                        if (unlikely(mem & 3 || len & 3))
 739                                mem_width = 0;
 740
 741                        desc->lli.saddr = reg;
 742                        desc->lli.daddr = mem;
 743                        desc->lli.ctrla = ctrla
 744                                        | ATC_DST_WIDTH(mem_width)
 745                                        | len >> reg_width;
 746                        desc->lli.ctrlb = ctrlb;
 747
 748                        atc_desc_chain(&first, &prev, desc);
 749                        total_len += len;
 750                }
 751                break;
 752        default:
 753                return NULL;
 754        }
 755
 756        /* set end-of-link to the last link descriptor of list*/
 757        set_desc_eol(prev);
 758
 759        /* First descriptor of the chain embedds additional information */
 760        first->txd.cookie = -EBUSY;
 761        first->len = total_len;
 762
 763        /* first link descriptor of list is responsible of flags */
 764        first->txd.flags = flags; /* client is in control of this ack */
 765
 766        return &first->txd;
 767
 768err_desc_get:
 769        dev_err(chan2dev(chan), "not enough descriptors available\n");
 770err:
 771        atc_desc_put(atchan, first);
 772        return NULL;
 773}
 774
 775/**
 776 * atc_dma_cyclic_check_values
 777 * Check for too big/unaligned periods and unaligned DMA buffer
 778 */
 779static int
 780atc_dma_cyclic_check_values(unsigned int reg_width, dma_addr_t buf_addr,
 781                size_t period_len, enum dma_transfer_direction direction)
 782{
 783        if (period_len > (ATC_BTSIZE_MAX << reg_width))
 784                goto err_out;
 785        if (unlikely(period_len & ((1 << reg_width) - 1)))
 786                goto err_out;
 787        if (unlikely(buf_addr & ((1 << reg_width) - 1)))
 788                goto err_out;
 789        if (unlikely(!(direction & (DMA_DEV_TO_MEM | DMA_MEM_TO_DEV))))
 790                goto err_out;
 791
 792        return 0;
 793
 794err_out:
 795        return -EINVAL;
 796}
 797
 798/**
 799 * atc_dma_cyclic_fill_desc - Fill one period decriptor
 800 */
 801static int
 802atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc,
 803                unsigned int period_index, dma_addr_t buf_addr,
 804                unsigned int reg_width, size_t period_len,
 805                enum dma_transfer_direction direction)
 806{
 807        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
 808        struct dma_slave_config *sconfig = &atchan->dma_sconfig;
 809        u32                     ctrla;
 810
 811        /* prepare common CRTLA value */
 812        ctrla =   ATC_SCSIZE(sconfig->src_maxburst)
 813                | ATC_DCSIZE(sconfig->dst_maxburst)
 814                | ATC_DST_WIDTH(reg_width)
 815                | ATC_SRC_WIDTH(reg_width)
 816                | period_len >> reg_width;
 817
 818        switch (direction) {
 819        case DMA_MEM_TO_DEV:
 820                desc->lli.saddr = buf_addr + (period_len * period_index);
 821                desc->lli.daddr = sconfig->dst_addr;
 822                desc->lli.ctrla = ctrla;
 823                desc->lli.ctrlb = ATC_DST_ADDR_MODE_FIXED
 824                                | ATC_SRC_ADDR_MODE_INCR
 825                                | ATC_FC_MEM2PER
 826                                | ATC_SIF(AT_DMA_MEM_IF)
 827                                | ATC_DIF(AT_DMA_PER_IF);
 828                break;
 829
 830        case DMA_DEV_TO_MEM:
 831                desc->lli.saddr = sconfig->src_addr;
 832                desc->lli.daddr = buf_addr + (period_len * period_index);
 833                desc->lli.ctrla = ctrla;
 834                desc->lli.ctrlb = ATC_DST_ADDR_MODE_INCR
 835                                | ATC_SRC_ADDR_MODE_FIXED
 836                                | ATC_FC_PER2MEM
 837                                | ATC_SIF(AT_DMA_PER_IF)
 838                                | ATC_DIF(AT_DMA_MEM_IF);
 839                break;
 840
 841        default:
 842                return -EINVAL;
 843        }
 844
 845        return 0;
 846}
 847
 848/**
 849 * atc_prep_dma_cyclic - prepare the cyclic DMA transfer
 850 * @chan: the DMA channel to prepare
 851 * @buf_addr: physical DMA address where the buffer starts
 852 * @buf_len: total number of bytes for the entire buffer
 853 * @period_len: number of bytes for each period
 854 * @direction: transfer direction, to or from device
 855 * @context: transfer context (ignored)
 856 */
 857static struct dma_async_tx_descriptor *
 858atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
 859                size_t period_len, enum dma_transfer_direction direction,
 860                void *context)
 861{
 862        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
 863        struct at_dma_slave     *atslave = chan->private;
 864        struct dma_slave_config *sconfig = &atchan->dma_sconfig;
 865        struct at_desc          *first = NULL;
 866        struct at_desc          *prev = NULL;
 867        unsigned long           was_cyclic;
 868        unsigned int            reg_width;
 869        unsigned int            periods = buf_len / period_len;
 870        unsigned int            i;
 871
 872        dev_vdbg(chan2dev(chan), "prep_dma_cyclic: %s buf@0x%08x - %d (%d/%d)\n",
 873                        direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE",
 874                        buf_addr,
 875                        periods, buf_len, period_len);
 876
 877        if (unlikely(!atslave || !buf_len || !period_len)) {
 878                dev_dbg(chan2dev(chan), "prep_dma_cyclic: length is zero!\n");
 879                return NULL;
 880        }
 881
 882        was_cyclic = test_and_set_bit(ATC_IS_CYCLIC, &atchan->status);
 883        if (was_cyclic) {
 884                dev_dbg(chan2dev(chan), "prep_dma_cyclic: channel in use!\n");
 885                return NULL;
 886        }
 887
 888        if (sconfig->direction == DMA_MEM_TO_DEV)
 889                reg_width = convert_buswidth(sconfig->dst_addr_width);
 890        else
 891                reg_width = convert_buswidth(sconfig->src_addr_width);
 892
 893        /* Check for too big/unaligned periods and unaligned DMA buffer */
 894        if (atc_dma_cyclic_check_values(reg_width, buf_addr,
 895                                        period_len, direction))
 896                goto err_out;
 897
 898        /* build cyclic linked list */
 899        for (i = 0; i < periods; i++) {
 900                struct at_desc  *desc;
 901
 902                desc = atc_desc_get(atchan);
 903                if (!desc)
 904                        goto err_desc_get;
 905
 906                if (atc_dma_cyclic_fill_desc(chan, desc, i, buf_addr,
 907                                             reg_width, period_len, direction))
 908                        goto err_desc_get;
 909
 910                atc_desc_chain(&first, &prev, desc);
 911        }
 912
 913        /* lets make a cyclic list */
 914        prev->lli.dscr = first->txd.phys;
 915
 916        /* First descriptor of the chain embedds additional information */
 917        first->txd.cookie = -EBUSY;
 918        first->len = buf_len;
 919
 920        return &first->txd;
 921
 922err_desc_get:
 923        dev_err(chan2dev(chan), "not enough descriptors available\n");
 924        atc_desc_put(atchan, first);
 925err_out:
 926        clear_bit(ATC_IS_CYCLIC, &atchan->status);
 927        return NULL;
 928}
 929
 930static int set_runtime_config(struct dma_chan *chan,
 931                              struct dma_slave_config *sconfig)
 932{
 933        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
 934
 935        /* Check if it is chan is configured for slave transfers */
 936        if (!chan->private)
 937                return -EINVAL;
 938
 939        memcpy(&atchan->dma_sconfig, sconfig, sizeof(*sconfig));
 940
 941        convert_burst(&atchan->dma_sconfig.src_maxburst);
 942        convert_burst(&atchan->dma_sconfig.dst_maxburst);
 943
 944        return 0;
 945}
 946
 947
 948static int atc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 949                       unsigned long arg)
 950{
 951        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
 952        struct at_dma           *atdma = to_at_dma(chan->device);
 953        int                     chan_id = atchan->chan_common.chan_id;
 954        unsigned long           flags;
 955
 956        LIST_HEAD(list);
 957
 958        dev_vdbg(chan2dev(chan), "atc_control (%d)\n", cmd);
 959
 960        if (cmd == DMA_PAUSE) {
 961                spin_lock_irqsave(&atchan->lock, flags);
 962
 963                dma_writel(atdma, CHER, AT_DMA_SUSP(chan_id));
 964                set_bit(ATC_IS_PAUSED, &atchan->status);
 965
 966                spin_unlock_irqrestore(&atchan->lock, flags);
 967        } else if (cmd == DMA_RESUME) {
 968                if (!atc_chan_is_paused(atchan))
 969                        return 0;
 970
 971                spin_lock_irqsave(&atchan->lock, flags);
 972
 973                dma_writel(atdma, CHDR, AT_DMA_RES(chan_id));
 974                clear_bit(ATC_IS_PAUSED, &atchan->status);
 975
 976                spin_unlock_irqrestore(&atchan->lock, flags);
 977        } else if (cmd == DMA_TERMINATE_ALL) {
 978                struct at_desc  *desc, *_desc;
 979                /*
 980                 * This is only called when something went wrong elsewhere, so
 981                 * we don't really care about the data. Just disable the
 982                 * channel. We still have to poll the channel enable bit due
 983                 * to AHB/HSB limitations.
 984                 */
 985                spin_lock_irqsave(&atchan->lock, flags);
 986
 987                /* disabling channel: must also remove suspend state */
 988                dma_writel(atdma, CHDR, AT_DMA_RES(chan_id) | atchan->mask);
 989
 990                /* confirm that this channel is disabled */
 991                while (dma_readl(atdma, CHSR) & atchan->mask)
 992                        cpu_relax();
 993
 994                /* active_list entries will end up before queued entries */
 995                list_splice_init(&atchan->queue, &list);
 996                list_splice_init(&atchan->active_list, &list);
 997
 998                /* Flush all pending and queued descriptors */
 999                list_for_each_entry_safe(desc, _desc, &list, desc_node)
1000                        atc_chain_complete(atchan, desc);
1001
1002                clear_bit(ATC_IS_PAUSED, &atchan->status);
1003                /* if channel dedicated to cyclic operations, free it */
1004                clear_bit(ATC_IS_CYCLIC, &atchan->status);
1005
1006                spin_unlock_irqrestore(&atchan->lock, flags);
1007        } else if (cmd == DMA_SLAVE_CONFIG) {
1008                return set_runtime_config(chan, (struct dma_slave_config *)arg);
1009        } else {
1010                return -ENXIO;
1011        }
1012
1013        return 0;
1014}
1015
1016/**
1017 * atc_tx_status - poll for transaction completion
1018 * @chan: DMA channel
1019 * @cookie: transaction identifier to check status of
1020 * @txstate: if not %NULL updated with transaction state
1021 *
1022 * If @txstate is passed in, upon return it reflect the driver
1023 * internal state and can be used with dma_async_is_complete() to check
1024 * the status of multiple cookies without re-checking hardware state.
1025 */
1026static enum dma_status
1027atc_tx_status(struct dma_chan *chan,
1028                dma_cookie_t cookie,
1029                struct dma_tx_state *txstate)
1030{
1031        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
1032        dma_cookie_t            last_used;
1033        dma_cookie_t            last_complete;
1034        unsigned long           flags;
1035        enum dma_status         ret;
1036
1037        spin_lock_irqsave(&atchan->lock, flags);
1038
1039        ret = dma_cookie_status(chan, cookie, txstate);
1040        if (ret != DMA_SUCCESS) {
1041                atc_cleanup_descriptors(atchan);
1042
1043                ret = dma_cookie_status(chan, cookie, txstate);
1044        }
1045
1046        last_complete = chan->completed_cookie;
1047        last_used = chan->cookie;
1048
1049        spin_unlock_irqrestore(&atchan->lock, flags);
1050
1051        if (ret != DMA_SUCCESS)
1052                dma_set_residue(txstate, atc_first_active(atchan)->len);
1053
1054        if (atc_chan_is_paused(atchan))
1055                ret = DMA_PAUSED;
1056
1057        dev_vdbg(chan2dev(chan), "tx_status %d: cookie = %d (d%d, u%d)\n",
1058                 ret, cookie, last_complete ? last_complete : 0,
1059                 last_used ? last_used : 0);
1060
1061        return ret;
1062}
1063
1064/**
1065 * atc_issue_pending - try to finish work
1066 * @chan: target DMA channel
1067 */
1068static void atc_issue_pending(struct dma_chan *chan)
1069{
1070        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
1071        unsigned long           flags;
1072
1073        dev_vdbg(chan2dev(chan), "issue_pending\n");
1074
1075        /* Not needed for cyclic transfers */
1076        if (atc_chan_is_cyclic(atchan))
1077                return;
1078
1079        spin_lock_irqsave(&atchan->lock, flags);
1080        if (!atc_chan_is_enabled(atchan)) {
1081                atc_advance_work(atchan);
1082        }
1083        spin_unlock_irqrestore(&atchan->lock, flags);
1084}
1085
1086/**
1087 * atc_alloc_chan_resources - allocate resources for DMA channel
1088 * @chan: allocate descriptor resources for this channel
1089 * @client: current client requesting the channel be ready for requests
1090 *
1091 * return - the number of allocated descriptors
1092 */
1093static int atc_alloc_chan_resources(struct dma_chan *chan)
1094{
1095        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
1096        struct at_dma           *atdma = to_at_dma(chan->device);
1097        struct at_desc          *desc;
1098        struct at_dma_slave     *atslave;
1099        unsigned long           flags;
1100        int                     i;
1101        u32                     cfg;
1102        LIST_HEAD(tmp_list);
1103
1104        dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
1105
1106        /* ASSERT:  channel is idle */
1107        if (atc_chan_is_enabled(atchan)) {
1108                dev_dbg(chan2dev(chan), "DMA channel not idle ?\n");
1109                return -EIO;
1110        }
1111
1112        cfg = ATC_DEFAULT_CFG;
1113
1114        atslave = chan->private;
1115        if (atslave) {
1116                /*
1117                 * We need controller-specific data to set up slave
1118                 * transfers.
1119                 */
1120                BUG_ON(!atslave->dma_dev || atslave->dma_dev != atdma->dma_common.dev);
1121
1122                /* if cfg configuration specified take it instad of default */
1123                if (atslave->cfg)
1124                        cfg = atslave->cfg;
1125        }
1126
1127        /* have we already been set up?
1128         * reconfigure channel but no need to reallocate descriptors */
1129        if (!list_empty(&atchan->free_list))
1130                return atchan->descs_allocated;
1131
1132        /* Allocate initial pool of descriptors */
1133        for (i = 0; i < init_nr_desc_per_channel; i++) {
1134                desc = atc_alloc_descriptor(chan, GFP_KERNEL);
1135                if (!desc) {
1136                        dev_err(atdma->dma_common.dev,
1137                                "Only %d initial descriptors\n", i);
1138                        break;
1139                }
1140                list_add_tail(&desc->desc_node, &tmp_list);
1141        }
1142
1143        spin_lock_irqsave(&atchan->lock, flags);
1144        atchan->descs_allocated = i;
1145        list_splice(&tmp_list, &atchan->free_list);
1146        dma_cookie_init(chan);
1147        spin_unlock_irqrestore(&atchan->lock, flags);
1148
1149        /* channel parameters */
1150        channel_writel(atchan, CFG, cfg);
1151
1152        dev_dbg(chan2dev(chan),
1153                "alloc_chan_resources: allocated %d descriptors\n",
1154                atchan->descs_allocated);
1155
1156        return atchan->descs_allocated;
1157}
1158
1159/**
1160 * atc_free_chan_resources - free all channel resources
1161 * @chan: DMA channel
1162 */
1163static void atc_free_chan_resources(struct dma_chan *chan)
1164{
1165        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
1166        struct at_dma           *atdma = to_at_dma(chan->device);
1167        struct at_desc          *desc, *_desc;
1168        LIST_HEAD(list);
1169
1170        dev_dbg(chan2dev(chan), "free_chan_resources: (descs allocated=%u)\n",
1171                atchan->descs_allocated);
1172
1173        /* ASSERT:  channel is idle */
1174        BUG_ON(!list_empty(&atchan->active_list));
1175        BUG_ON(!list_empty(&atchan->queue));
1176        BUG_ON(atc_chan_is_enabled(atchan));
1177
1178        list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) {
1179                dev_vdbg(chan2dev(chan), "  freeing descriptor %p\n", desc);
1180                list_del(&desc->desc_node);
1181                /* free link descriptor */
1182                dma_pool_free(atdma->dma_desc_pool, desc, desc->txd.phys);
1183        }
1184        list_splice_init(&atchan->free_list, &list);
1185        atchan->descs_allocated = 0;
1186        atchan->status = 0;
1187
1188        dev_vdbg(chan2dev(chan), "free_chan_resources: done\n");
1189}
1190
1191
1192/*--  Module Management  -----------------------------------------------*/
1193
1194/* cap_mask is a multi-u32 bitfield, fill it with proper C code. */
1195static struct at_dma_platform_data at91sam9rl_config = {
1196        .nr_channels = 2,
1197};
1198static struct at_dma_platform_data at91sam9g45_config = {
1199        .nr_channels = 8,
1200};
1201
1202#if defined(CONFIG_OF)
1203static const struct of_device_id atmel_dma_dt_ids[] = {
1204        {
1205                .compatible = "atmel,at91sam9rl-dma",
1206                .data = &at91sam9rl_config,
1207        }, {
1208                .compatible = "atmel,at91sam9g45-dma",
1209                .data = &at91sam9g45_config,
1210        }, {
1211                /* sentinel */
1212        }
1213};
1214
1215MODULE_DEVICE_TABLE(of, atmel_dma_dt_ids);
1216#endif
1217
1218static const struct platform_device_id atdma_devtypes[] = {
1219        {
1220                .name = "at91sam9rl_dma",
1221                .driver_data = (unsigned long) &at91sam9rl_config,
1222        }, {
1223                .name = "at91sam9g45_dma",
1224                .driver_data = (unsigned long) &at91sam9g45_config,
1225        }, {
1226                /* sentinel */
1227        }
1228};
1229
1230static inline const struct at_dma_platform_data * __init at_dma_get_driver_data(
1231                                                struct platform_device *pdev)
1232{
1233        if (pdev->dev.of_node) {
1234                const struct of_device_id *match;
1235                match = of_match_node(atmel_dma_dt_ids, pdev->dev.of_node);
1236                if (match == NULL)
1237                        return NULL;
1238                return match->data;
1239        }
1240        return (struct at_dma_platform_data *)
1241                        platform_get_device_id(pdev)->driver_data;
1242}
1243
1244/**
1245 * at_dma_off - disable DMA controller
1246 * @atdma: the Atmel HDAMC device
1247 */
1248static void at_dma_off(struct at_dma *atdma)
1249{
1250        dma_writel(atdma, EN, 0);
1251
1252        /* disable all interrupts */
1253        dma_writel(atdma, EBCIDR, -1L);
1254
1255        /* confirm that all channels are disabled */
1256        while (dma_readl(atdma, CHSR) & atdma->all_chan_mask)
1257                cpu_relax();
1258}
1259
1260static int __init at_dma_probe(struct platform_device *pdev)
1261{
1262        struct resource         *io;
1263        struct at_dma           *atdma;
1264        size_t                  size;
1265        int                     irq;
1266        int                     err;
1267        int                     i;
1268        const struct at_dma_platform_data *plat_dat;
1269
1270        /* setup platform data for each SoC */
1271        dma_cap_set(DMA_MEMCPY, at91sam9rl_config.cap_mask);
1272        dma_cap_set(DMA_MEMCPY, at91sam9g45_config.cap_mask);
1273        dma_cap_set(DMA_SLAVE, at91sam9g45_config.cap_mask);
1274
1275        /* get DMA parameters from controller type */
1276        plat_dat = at_dma_get_driver_data(pdev);
1277        if (!plat_dat)
1278                return -ENODEV;
1279
1280        io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1281        if (!io)
1282                return -EINVAL;
1283
1284        irq = platform_get_irq(pdev, 0);
1285        if (irq < 0)
1286                return irq;
1287
1288        size = sizeof(struct at_dma);
1289        size += plat_dat->nr_channels * sizeof(struct at_dma_chan);
1290        atdma = kzalloc(size, GFP_KERNEL);
1291        if (!atdma)
1292                return -ENOMEM;
1293
1294        /* discover transaction capabilities */
1295        atdma->dma_common.cap_mask = plat_dat->cap_mask;
1296        atdma->all_chan_mask = (1 << plat_dat->nr_channels) - 1;
1297
1298        size = resource_size(io);
1299        if (!request_mem_region(io->start, size, pdev->dev.driver->name)) {
1300                err = -EBUSY;
1301                goto err_kfree;
1302        }
1303
1304        atdma->regs = ioremap(io->start, size);
1305        if (!atdma->regs) {
1306                err = -ENOMEM;
1307                goto err_release_r;
1308        }
1309
1310        atdma->clk = clk_get(&pdev->dev, "dma_clk");
1311        if (IS_ERR(atdma->clk)) {
1312                err = PTR_ERR(atdma->clk);
1313                goto err_clk;
1314        }
1315        clk_enable(atdma->clk);
1316
1317        /* force dma off, just in case */
1318        at_dma_off(atdma);
1319
1320        err = request_irq(irq, at_dma_interrupt, 0, "at_hdmac", atdma);
1321        if (err)
1322                goto err_irq;
1323
1324        platform_set_drvdata(pdev, atdma);
1325
1326        /* create a pool of consistent memory blocks for hardware descriptors */
1327        atdma->dma_desc_pool = dma_pool_create("at_hdmac_desc_pool",
1328                        &pdev->dev, sizeof(struct at_desc),
1329                        4 /* word alignment */, 0);
1330        if (!atdma->dma_desc_pool) {
1331                dev_err(&pdev->dev, "No memory for descriptors dma pool\n");
1332                err = -ENOMEM;
1333                goto err_pool_create;
1334        }
1335
1336        /* clear any pending interrupt */
1337        while (dma_readl(atdma, EBCISR))
1338                cpu_relax();
1339
1340        /* initialize channels related values */
1341        INIT_LIST_HEAD(&atdma->dma_common.channels);
1342        for (i = 0; i < plat_dat->nr_channels; i++) {
1343                struct at_dma_chan      *atchan = &atdma->chan[i];
1344
1345                atchan->chan_common.device = &atdma->dma_common;
1346                dma_cookie_init(&atchan->chan_common);
1347                list_add_tail(&atchan->chan_common.device_node,
1348                                &atdma->dma_common.channels);
1349
1350                atchan->ch_regs = atdma->regs + ch_regs(i);
1351                spin_lock_init(&atchan->lock);
1352                atchan->mask = 1 << i;
1353
1354                INIT_LIST_HEAD(&atchan->active_list);
1355                INIT_LIST_HEAD(&atchan->queue);
1356                INIT_LIST_HEAD(&atchan->free_list);
1357
1358                tasklet_init(&atchan->tasklet, atc_tasklet,
1359                                (unsigned long)atchan);
1360                atc_enable_chan_irq(atdma, i);
1361        }
1362
1363        /* set base routines */
1364        atdma->dma_common.device_alloc_chan_resources = atc_alloc_chan_resources;
1365        atdma->dma_common.device_free_chan_resources = atc_free_chan_resources;
1366        atdma->dma_common.device_tx_status = atc_tx_status;
1367        atdma->dma_common.device_issue_pending = atc_issue_pending;
1368        atdma->dma_common.dev = &pdev->dev;
1369
1370        /* set prep routines based on capability */
1371        if (dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask))
1372                atdma->dma_common.device_prep_dma_memcpy = atc_prep_dma_memcpy;
1373
1374        if (dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask)) {
1375                atdma->dma_common.device_prep_slave_sg = atc_prep_slave_sg;
1376                /* controller can do slave DMA: can trigger cyclic transfers */
1377                dma_cap_set(DMA_CYCLIC, atdma->dma_common.cap_mask);
1378                atdma->dma_common.device_prep_dma_cyclic = atc_prep_dma_cyclic;
1379                atdma->dma_common.device_control = atc_control;
1380        }
1381
1382        dma_writel(atdma, EN, AT_DMA_ENABLE);
1383
1384        dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s), %d channels\n",
1385          dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask) ? "cpy " : "",
1386          dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask)  ? "slave " : "",
1387          plat_dat->nr_channels);
1388
1389        dma_async_device_register(&atdma->dma_common);
1390
1391        return 0;
1392
1393err_pool_create:
1394        platform_set_drvdata(pdev, NULL);
1395        free_irq(platform_get_irq(pdev, 0), atdma);
1396err_irq:
1397        clk_disable(atdma->clk);
1398        clk_put(atdma->clk);
1399err_clk:
1400        iounmap(atdma->regs);
1401        atdma->regs = NULL;
1402err_release_r:
1403        release_mem_region(io->start, size);
1404err_kfree:
1405        kfree(atdma);
1406        return err;
1407}
1408
1409static int __exit at_dma_remove(struct platform_device *pdev)
1410{
1411        struct at_dma           *atdma = platform_get_drvdata(pdev);
1412        struct dma_chan         *chan, *_chan;
1413        struct resource         *io;
1414
1415        at_dma_off(atdma);
1416        dma_async_device_unregister(&atdma->dma_common);
1417
1418        dma_pool_destroy(atdma->dma_desc_pool);
1419        platform_set_drvdata(pdev, NULL);
1420        free_irq(platform_get_irq(pdev, 0), atdma);
1421
1422        list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
1423                        device_node) {
1424                struct at_dma_chan      *atchan = to_at_dma_chan(chan);
1425
1426                /* Disable interrupts */
1427                atc_disable_chan_irq(atdma, chan->chan_id);
1428                tasklet_disable(&atchan->tasklet);
1429
1430                tasklet_kill(&atchan->tasklet);
1431                list_del(&chan->device_node);
1432        }
1433
1434        clk_disable(atdma->clk);
1435        clk_put(atdma->clk);
1436
1437        iounmap(atdma->regs);
1438        atdma->regs = NULL;
1439
1440        io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1441        release_mem_region(io->start, resource_size(io));
1442
1443        kfree(atdma);
1444
1445        return 0;
1446}
1447
1448static void at_dma_shutdown(struct platform_device *pdev)
1449{
1450        struct at_dma   *atdma = platform_get_drvdata(pdev);
1451
1452        at_dma_off(platform_get_drvdata(pdev));
1453        clk_disable(atdma->clk);
1454}
1455
1456static int at_dma_prepare(struct device *dev)
1457{
1458        struct platform_device *pdev = to_platform_device(dev);
1459        struct at_dma *atdma = platform_get_drvdata(pdev);
1460        struct dma_chan *chan, *_chan;
1461
1462        list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
1463                        device_node) {
1464                struct at_dma_chan *atchan = to_at_dma_chan(chan);
1465                /* wait for transaction completion (except in cyclic case) */
1466                if (atc_chan_is_enabled(atchan) && !atc_chan_is_cyclic(atchan))
1467                        return -EAGAIN;
1468        }
1469        return 0;
1470}
1471
1472static void atc_suspend_cyclic(struct at_dma_chan *atchan)
1473{
1474        struct dma_chan *chan = &atchan->chan_common;
1475
1476        /* Channel should be paused by user
1477         * do it anyway even if it is not done already */
1478        if (!atc_chan_is_paused(atchan)) {
1479                dev_warn(chan2dev(chan),
1480                "cyclic channel not paused, should be done by channel user\n");
1481                atc_control(chan, DMA_PAUSE, 0);
1482        }
1483
1484        /* now preserve additional data for cyclic operations */
1485        /* next descriptor address in the cyclic list */
1486        atchan->save_dscr = channel_readl(atchan, DSCR);
1487
1488        vdbg_dump_regs(atchan);
1489}
1490
1491static int at_dma_suspend_noirq(struct device *dev)
1492{
1493        struct platform_device *pdev = to_platform_device(dev);
1494        struct at_dma *atdma = platform_get_drvdata(pdev);
1495        struct dma_chan *chan, *_chan;
1496
1497        /* preserve data */
1498        list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
1499                        device_node) {
1500                struct at_dma_chan *atchan = to_at_dma_chan(chan);
1501
1502                if (atc_chan_is_cyclic(atchan))
1503                        atc_suspend_cyclic(atchan);
1504                atchan->save_cfg = channel_readl(atchan, CFG);
1505        }
1506        atdma->save_imr = dma_readl(atdma, EBCIMR);
1507
1508        /* disable DMA controller */
1509        at_dma_off(atdma);
1510        clk_disable(atdma->clk);
1511        return 0;
1512}
1513
1514static void atc_resume_cyclic(struct at_dma_chan *atchan)
1515{
1516        struct at_dma   *atdma = to_at_dma(atchan->chan_common.device);
1517
1518        /* restore channel status for cyclic descriptors list:
1519         * next descriptor in the cyclic list at the time of suspend */
1520        channel_writel(atchan, SADDR, 0);
1521        channel_writel(atchan, DADDR, 0);
1522        channel_writel(atchan, CTRLA, 0);
1523        channel_writel(atchan, CTRLB, 0);
1524        channel_writel(atchan, DSCR, atchan->save_dscr);
1525        dma_writel(atdma, CHER, atchan->mask);
1526
1527        /* channel pause status should be removed by channel user
1528         * We cannot take the initiative to do it here */
1529
1530        vdbg_dump_regs(atchan);
1531}
1532
1533static int at_dma_resume_noirq(struct device *dev)
1534{
1535        struct platform_device *pdev = to_platform_device(dev);
1536        struct at_dma *atdma = platform_get_drvdata(pdev);
1537        struct dma_chan *chan, *_chan;
1538
1539        /* bring back DMA controller */
1540        clk_enable(atdma->clk);
1541        dma_writel(atdma, EN, AT_DMA_ENABLE);
1542
1543        /* clear any pending interrupt */
1544        while (dma_readl(atdma, EBCISR))
1545                cpu_relax();
1546
1547        /* restore saved data */
1548        dma_writel(atdma, EBCIER, atdma->save_imr);
1549        list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
1550                        device_node) {
1551                struct at_dma_chan *atchan = to_at_dma_chan(chan);
1552
1553                channel_writel(atchan, CFG, atchan->save_cfg);
1554                if (atc_chan_is_cyclic(atchan))
1555                        atc_resume_cyclic(atchan);
1556        }
1557        return 0;
1558}
1559
1560static const struct dev_pm_ops at_dma_dev_pm_ops = {
1561        .prepare = at_dma_prepare,
1562        .suspend_noirq = at_dma_suspend_noirq,
1563        .resume_noirq = at_dma_resume_noirq,
1564};
1565
1566static struct platform_driver at_dma_driver = {
1567        .remove         = __exit_p(at_dma_remove),
1568        .shutdown       = at_dma_shutdown,
1569        .id_table       = atdma_devtypes,
1570        .driver = {
1571                .name   = "at_hdmac",
1572                .pm     = &at_dma_dev_pm_ops,
1573                .of_match_table = of_match_ptr(atmel_dma_dt_ids),
1574        },
1575};
1576
1577static int __init at_dma_init(void)
1578{
1579        return platform_driver_probe(&at_dma_driver, at_dma_probe);
1580}
1581subsys_initcall(at_dma_init);
1582
1583static void __exit at_dma_exit(void)
1584{
1585        platform_driver_unregister(&at_dma_driver);
1586}
1587module_exit(at_dma_exit);
1588
1589MODULE_DESCRIPTION("Atmel AHB DMA Controller driver");
1590MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>");
1591MODULE_LICENSE("GPL");
1592MODULE_ALIAS("platform:at_hdmac");
1593
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