linux/drivers/dma/fsldma.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Freescale MPC85xx, MPC83xx DMA Engine support
   4 *
   5 * Copyright (C) 2007-2010 Freescale Semiconductor, Inc. All rights reserved.
   6 *
   7 * Author:
   8 *   Zhang Wei <wei.zhang@freescale.com>, Jul 2007
   9 *   Ebony Zhu <ebony.zhu@freescale.com>, May 2007
  10 *
  11 * Description:
  12 *   DMA engine driver for Freescale MPC8540 DMA controller, which is
  13 *   also fit for MPC8560, MPC8555, MPC8548, MPC8641, and etc.
  14 *   The support for MPC8349 DMA controller is also added.
  15 *
  16 * This driver instructs the DMA controller to issue the PCI Read Multiple
  17 * command for PCI read operations, instead of using the default PCI Read Line
  18 * command. Please be aware that this setting may result in read pre-fetching
  19 * on some platforms.
  20 */
  21
  22#include <linux/init.h>
  23#include <linux/module.h>
  24#include <linux/pci.h>
  25#include <linux/slab.h>
  26#include <linux/interrupt.h>
  27#include <linux/dmaengine.h>
  28#include <linux/delay.h>
  29#include <linux/dma-mapping.h>
  30#include <linux/dmapool.h>
  31#include <linux/of_address.h>
  32#include <linux/of_irq.h>
  33#include <linux/of_platform.h>
  34#include <linux/fsldma.h>
  35#include "dmaengine.h"
  36#include "fsldma.h"
  37
  38#define chan_dbg(chan, fmt, arg...)                                     \
  39        dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
  40#define chan_err(chan, fmt, arg...)                                     \
  41        dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
  42
  43static const char msg_ld_oom[] = "No free memory for link descriptor";
  44
  45/*
  46 * Register Helpers
  47 */
  48
  49static void set_sr(struct fsldma_chan *chan, u32 val)
  50{
  51        FSL_DMA_OUT(chan, &chan->regs->sr, val, 32);
  52}
  53
  54static u32 get_sr(struct fsldma_chan *chan)
  55{
  56        return FSL_DMA_IN(chan, &chan->regs->sr, 32);
  57}
  58
  59static void set_mr(struct fsldma_chan *chan, u32 val)
  60{
  61        FSL_DMA_OUT(chan, &chan->regs->mr, val, 32);
  62}
  63
  64static u32 get_mr(struct fsldma_chan *chan)
  65{
  66        return FSL_DMA_IN(chan, &chan->regs->mr, 32);
  67}
  68
  69static void set_cdar(struct fsldma_chan *chan, dma_addr_t addr)
  70{
  71        FSL_DMA_OUT(chan, &chan->regs->cdar, addr | FSL_DMA_SNEN, 64);
  72}
  73
  74static dma_addr_t get_cdar(struct fsldma_chan *chan)
  75{
  76        return FSL_DMA_IN(chan, &chan->regs->cdar, 64) & ~FSL_DMA_SNEN;
  77}
  78
  79static void set_bcr(struct fsldma_chan *chan, u32 val)
  80{
  81        FSL_DMA_OUT(chan, &chan->regs->bcr, val, 32);
  82}
  83
  84static u32 get_bcr(struct fsldma_chan *chan)
  85{
  86        return FSL_DMA_IN(chan, &chan->regs->bcr, 32);
  87}
  88
  89/*
  90 * Descriptor Helpers
  91 */
  92
  93static void set_desc_cnt(struct fsldma_chan *chan,
  94                                struct fsl_dma_ld_hw *hw, u32 count)
  95{
  96        hw->count = CPU_TO_DMA(chan, count, 32);
  97}
  98
  99static void set_desc_src(struct fsldma_chan *chan,
 100                         struct fsl_dma_ld_hw *hw, dma_addr_t src)
 101{
 102        u64 snoop_bits;
 103
 104        snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
 105                ? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0;
 106        hw->src_addr = CPU_TO_DMA(chan, snoop_bits | src, 64);
 107}
 108
 109static void set_desc_dst(struct fsldma_chan *chan,
 110                         struct fsl_dma_ld_hw *hw, dma_addr_t dst)
 111{
 112        u64 snoop_bits;
 113
 114        snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
 115                ? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0;
 116        hw->dst_addr = CPU_TO_DMA(chan, snoop_bits | dst, 64);
 117}
 118
 119static void set_desc_next(struct fsldma_chan *chan,
 120                          struct fsl_dma_ld_hw *hw, dma_addr_t next)
 121{
 122        u64 snoop_bits;
 123
 124        snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
 125                ? FSL_DMA_SNEN : 0;
 126        hw->next_ln_addr = CPU_TO_DMA(chan, snoop_bits | next, 64);
 127}
 128
 129static void set_ld_eol(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
 130{
 131        u64 snoop_bits;
 132
 133        snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
 134                ? FSL_DMA_SNEN : 0;
 135
 136        desc->hw.next_ln_addr = CPU_TO_DMA(chan,
 137                DMA_TO_CPU(chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL
 138                        | snoop_bits, 64);
 139}
 140
 141/*
 142 * DMA Engine Hardware Control Helpers
 143 */
 144
 145static void dma_init(struct fsldma_chan *chan)
 146{
 147        /* Reset the channel */
 148        set_mr(chan, 0);
 149
 150        switch (chan->feature & FSL_DMA_IP_MASK) {
 151        case FSL_DMA_IP_85XX:
 152                /* Set the channel to below modes:
 153                 * EIE - Error interrupt enable
 154                 * EOLNIE - End of links interrupt enable
 155                 * BWC - Bandwidth sharing among channels
 156                 */
 157                set_mr(chan, FSL_DMA_MR_BWC | FSL_DMA_MR_EIE
 158                        | FSL_DMA_MR_EOLNIE);
 159                break;
 160        case FSL_DMA_IP_83XX:
 161                /* Set the channel to below modes:
 162                 * EOTIE - End-of-transfer interrupt enable
 163                 * PRC_RM - PCI read multiple
 164                 */
 165                set_mr(chan, FSL_DMA_MR_EOTIE | FSL_DMA_MR_PRC_RM);
 166                break;
 167        }
 168}
 169
 170static int dma_is_idle(struct fsldma_chan *chan)
 171{
 172        u32 sr = get_sr(chan);
 173        return (!(sr & FSL_DMA_SR_CB)) || (sr & FSL_DMA_SR_CH);
 174}
 175
 176/*
 177 * Start the DMA controller
 178 *
 179 * Preconditions:
 180 * - the CDAR register must point to the start descriptor
 181 * - the MRn[CS] bit must be cleared
 182 */
 183static void dma_start(struct fsldma_chan *chan)
 184{
 185        u32 mode;
 186
 187        mode = get_mr(chan);
 188
 189        if (chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
 190                set_bcr(chan, 0);
 191                mode |= FSL_DMA_MR_EMP_EN;
 192        } else {
 193                mode &= ~FSL_DMA_MR_EMP_EN;
 194        }
 195
 196        if (chan->feature & FSL_DMA_CHAN_START_EXT) {
 197                mode |= FSL_DMA_MR_EMS_EN;
 198        } else {
 199                mode &= ~FSL_DMA_MR_EMS_EN;
 200                mode |= FSL_DMA_MR_CS;
 201        }
 202
 203        set_mr(chan, mode);
 204}
 205
 206static void dma_halt(struct fsldma_chan *chan)
 207{
 208        u32 mode;
 209        int i;
 210
 211        /* read the mode register */
 212        mode = get_mr(chan);
 213
 214        /*
 215         * The 85xx controller supports channel abort, which will stop
 216         * the current transfer. On 83xx, this bit is the transfer error
 217         * mask bit, which should not be changed.
 218         */
 219        if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
 220                mode |= FSL_DMA_MR_CA;
 221                set_mr(chan, mode);
 222
 223                mode &= ~FSL_DMA_MR_CA;
 224        }
 225
 226        /* stop the DMA controller */
 227        mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN);
 228        set_mr(chan, mode);
 229
 230        /* wait for the DMA controller to become idle */
 231        for (i = 0; i < 100; i++) {
 232                if (dma_is_idle(chan))
 233                        return;
 234
 235                udelay(10);
 236        }
 237
 238        if (!dma_is_idle(chan))
 239                chan_err(chan, "DMA halt timeout!\n");
 240}
 241
 242/**
 243 * fsl_chan_set_src_loop_size - Set source address hold transfer size
 244 * @chan : Freescale DMA channel
 245 * @size     : Address loop size, 0 for disable loop
 246 *
 247 * The set source address hold transfer size. The source
 248 * address hold or loop transfer size is when the DMA transfer
 249 * data from source address (SA), if the loop size is 4, the DMA will
 250 * read data from SA, SA + 1, SA + 2, SA + 3, then loop back to SA,
 251 * SA + 1 ... and so on.
 252 */
 253static void fsl_chan_set_src_loop_size(struct fsldma_chan *chan, int size)
 254{
 255        u32 mode;
 256
 257        mode = get_mr(chan);
 258
 259        switch (size) {
 260        case 0:
 261                mode &= ~FSL_DMA_MR_SAHE;
 262                break;
 263        case 1:
 264        case 2:
 265        case 4:
 266        case 8:
 267                mode &= ~FSL_DMA_MR_SAHTS_MASK;
 268                mode |= FSL_DMA_MR_SAHE | (__ilog2(size) << 14);
 269                break;
 270        }
 271
 272        set_mr(chan, mode);
 273}
 274
 275/**
 276 * fsl_chan_set_dst_loop_size - Set destination address hold transfer size
 277 * @chan : Freescale DMA channel
 278 * @size     : Address loop size, 0 for disable loop
 279 *
 280 * The set destination address hold transfer size. The destination
 281 * address hold or loop transfer size is when the DMA transfer
 282 * data to destination address (TA), if the loop size is 4, the DMA will
 283 * write data to TA, TA + 1, TA + 2, TA + 3, then loop back to TA,
 284 * TA + 1 ... and so on.
 285 */
 286static void fsl_chan_set_dst_loop_size(struct fsldma_chan *chan, int size)
 287{
 288        u32 mode;
 289
 290        mode = get_mr(chan);
 291
 292        switch (size) {
 293        case 0:
 294                mode &= ~FSL_DMA_MR_DAHE;
 295                break;
 296        case 1:
 297        case 2:
 298        case 4:
 299        case 8:
 300                mode &= ~FSL_DMA_MR_DAHTS_MASK;
 301                mode |= FSL_DMA_MR_DAHE | (__ilog2(size) << 16);
 302                break;
 303        }
 304
 305        set_mr(chan, mode);
 306}
 307
 308/**
 309 * fsl_chan_set_request_count - Set DMA Request Count for external control
 310 * @chan : Freescale DMA channel
 311 * @size     : Number of bytes to transfer in a single request
 312 *
 313 * The Freescale DMA channel can be controlled by the external signal DREQ#.
 314 * The DMA request count is how many bytes are allowed to transfer before
 315 * pausing the channel, after which a new assertion of DREQ# resumes channel
 316 * operation.
 317 *
 318 * A size of 0 disables external pause control. The maximum size is 1024.
 319 */
 320static void fsl_chan_set_request_count(struct fsldma_chan *chan, int size)
 321{
 322        u32 mode;
 323
 324        BUG_ON(size > 1024);
 325
 326        mode = get_mr(chan);
 327        mode &= ~FSL_DMA_MR_BWC_MASK;
 328        mode |= (__ilog2(size) << 24) & FSL_DMA_MR_BWC_MASK;
 329
 330        set_mr(chan, mode);
 331}
 332
 333/**
 334 * fsl_chan_toggle_ext_pause - Toggle channel external pause status
 335 * @chan : Freescale DMA channel
 336 * @enable   : 0 is disabled, 1 is enabled.
 337 *
 338 * The Freescale DMA channel can be controlled by the external signal DREQ#.
 339 * The DMA Request Count feature should be used in addition to this feature
 340 * to set the number of bytes to transfer before pausing the channel.
 341 */
 342static void fsl_chan_toggle_ext_pause(struct fsldma_chan *chan, int enable)
 343{
 344        if (enable)
 345                chan->feature |= FSL_DMA_CHAN_PAUSE_EXT;
 346        else
 347                chan->feature &= ~FSL_DMA_CHAN_PAUSE_EXT;
 348}
 349
 350/**
 351 * fsl_chan_toggle_ext_start - Toggle channel external start status
 352 * @chan : Freescale DMA channel
 353 * @enable   : 0 is disabled, 1 is enabled.
 354 *
 355 * If enable the external start, the channel can be started by an
 356 * external DMA start pin. So the dma_start() does not start the
 357 * transfer immediately. The DMA channel will wait for the
 358 * control pin asserted.
 359 */
 360static void fsl_chan_toggle_ext_start(struct fsldma_chan *chan, int enable)
 361{
 362        if (enable)
 363                chan->feature |= FSL_DMA_CHAN_START_EXT;
 364        else
 365                chan->feature &= ~FSL_DMA_CHAN_START_EXT;
 366}
 367
 368int fsl_dma_external_start(struct dma_chan *dchan, int enable)
 369{
 370        struct fsldma_chan *chan;
 371
 372        if (!dchan)
 373                return -EINVAL;
 374
 375        chan = to_fsl_chan(dchan);
 376
 377        fsl_chan_toggle_ext_start(chan, enable);
 378        return 0;
 379}
 380EXPORT_SYMBOL_GPL(fsl_dma_external_start);
 381
 382static void append_ld_queue(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
 383{
 384        struct fsl_desc_sw *tail = to_fsl_desc(chan->ld_pending.prev);
 385
 386        if (list_empty(&chan->ld_pending))
 387                goto out_splice;
 388
 389        /*
 390         * Add the hardware descriptor to the chain of hardware descriptors
 391         * that already exists in memory.
 392         *
 393         * This will un-set the EOL bit of the existing transaction, and the
 394         * last link in this transaction will become the EOL descriptor.
 395         */
 396        set_desc_next(chan, &tail->hw, desc->async_tx.phys);
 397
 398        /*
 399         * Add the software descriptor and all children to the list
 400         * of pending transactions
 401         */
 402out_splice:
 403        list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
 404}
 405
 406static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
 407{
 408        struct fsldma_chan *chan = to_fsl_chan(tx->chan);
 409        struct fsl_desc_sw *desc = tx_to_fsl_desc(tx);
 410        struct fsl_desc_sw *child;
 411        dma_cookie_t cookie = -EINVAL;
 412
 413        spin_lock_bh(&chan->desc_lock);
 414
 415#ifdef CONFIG_PM
 416        if (unlikely(chan->pm_state != RUNNING)) {
 417                chan_dbg(chan, "cannot submit due to suspend\n");
 418                spin_unlock_bh(&chan->desc_lock);
 419                return -1;
 420        }
 421#endif
 422
 423        /*
 424         * assign cookies to all of the software descriptors
 425         * that make up this transaction
 426         */
 427        list_for_each_entry(child, &desc->tx_list, node) {
 428                cookie = dma_cookie_assign(&child->async_tx);
 429        }
 430
 431        /* put this transaction onto the tail of the pending queue */
 432        append_ld_queue(chan, desc);
 433
 434        spin_unlock_bh(&chan->desc_lock);
 435
 436        return cookie;
 437}
 438
 439/**
 440 * fsl_dma_free_descriptor - Free descriptor from channel's DMA pool.
 441 * @chan : Freescale DMA channel
 442 * @desc: descriptor to be freed
 443 */
 444static void fsl_dma_free_descriptor(struct fsldma_chan *chan,
 445                struct fsl_desc_sw *desc)
 446{
 447        list_del(&desc->node);
 448        chan_dbg(chan, "LD %p free\n", desc);
 449        dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
 450}
 451
 452/**
 453 * fsl_dma_alloc_descriptor - Allocate descriptor from channel's DMA pool.
 454 * @chan : Freescale DMA channel
 455 *
 456 * Return - The descriptor allocated. NULL for failed.
 457 */
 458static struct fsl_desc_sw *fsl_dma_alloc_descriptor(struct fsldma_chan *chan)
 459{
 460        struct fsl_desc_sw *desc;
 461        dma_addr_t pdesc;
 462
 463        desc = dma_pool_zalloc(chan->desc_pool, GFP_ATOMIC, &pdesc);
 464        if (!desc) {
 465                chan_dbg(chan, "out of memory for link descriptor\n");
 466                return NULL;
 467        }
 468
 469        INIT_LIST_HEAD(&desc->tx_list);
 470        dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
 471        desc->async_tx.tx_submit = fsl_dma_tx_submit;
 472        desc->async_tx.phys = pdesc;
 473
 474        chan_dbg(chan, "LD %p allocated\n", desc);
 475
 476        return desc;
 477}
 478
 479/**
 480 * fsldma_clean_completed_descriptor - free all descriptors which
 481 * has been completed and acked
 482 * @chan: Freescale DMA channel
 483 *
 484 * This function is used on all completed and acked descriptors.
 485 * All descriptors should only be freed in this function.
 486 */
 487static void fsldma_clean_completed_descriptor(struct fsldma_chan *chan)
 488{
 489        struct fsl_desc_sw *desc, *_desc;
 490
 491        /* Run the callback for each descriptor, in order */
 492        list_for_each_entry_safe(desc, _desc, &chan->ld_completed, node)
 493                if (async_tx_test_ack(&desc->async_tx))
 494                        fsl_dma_free_descriptor(chan, desc);
 495}
 496
 497/**
 498 * fsldma_run_tx_complete_actions - cleanup a single link descriptor
 499 * @chan: Freescale DMA channel
 500 * @desc: descriptor to cleanup and free
 501 * @cookie: Freescale DMA transaction identifier
 502 *
 503 * This function is used on a descriptor which has been executed by the DMA
 504 * controller. It will run any callbacks, submit any dependencies.
 505 */
 506static dma_cookie_t fsldma_run_tx_complete_actions(struct fsldma_chan *chan,
 507                struct fsl_desc_sw *desc, dma_cookie_t cookie)
 508{
 509        struct dma_async_tx_descriptor *txd = &desc->async_tx;
 510        dma_cookie_t ret = cookie;
 511
 512        BUG_ON(txd->cookie < 0);
 513
 514        if (txd->cookie > 0) {
 515                ret = txd->cookie;
 516
 517                dma_descriptor_unmap(txd);
 518                /* Run the link descriptor callback function */
 519                dmaengine_desc_get_callback_invoke(txd, NULL);
 520        }
 521
 522        /* Run any dependencies */
 523        dma_run_dependencies(txd);
 524
 525        return ret;
 526}
 527
 528/**
 529 * fsldma_clean_running_descriptor - move the completed descriptor from
 530 * ld_running to ld_completed
 531 * @chan: Freescale DMA channel
 532 * @desc: the descriptor which is completed
 533 *
 534 * Free the descriptor directly if acked by async_tx api, or move it to
 535 * queue ld_completed.
 536 */
 537static void fsldma_clean_running_descriptor(struct fsldma_chan *chan,
 538                struct fsl_desc_sw *desc)
 539{
 540        /* Remove from the list of transactions */
 541        list_del(&desc->node);
 542
 543        /*
 544         * the client is allowed to attach dependent operations
 545         * until 'ack' is set
 546         */
 547        if (!async_tx_test_ack(&desc->async_tx)) {
 548                /*
 549                 * Move this descriptor to the list of descriptors which is
 550                 * completed, but still awaiting the 'ack' bit to be set.
 551                 */
 552                list_add_tail(&desc->node, &chan->ld_completed);
 553                return;
 554        }
 555
 556        dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
 557}
 558
 559/**
 560 * fsl_chan_xfer_ld_queue - transfer any pending transactions
 561 * @chan : Freescale DMA channel
 562 *
 563 * HARDWARE STATE: idle
 564 * LOCKING: must hold chan->desc_lock
 565 */
 566static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
 567{
 568        struct fsl_desc_sw *desc;
 569
 570        /*
 571         * If the list of pending descriptors is empty, then we
 572         * don't need to do any work at all
 573         */
 574        if (list_empty(&chan->ld_pending)) {
 575                chan_dbg(chan, "no pending LDs\n");
 576                return;
 577        }
 578
 579        /*
 580         * The DMA controller is not idle, which means that the interrupt
 581         * handler will start any queued transactions when it runs after
 582         * this transaction finishes
 583         */
 584        if (!chan->idle) {
 585                chan_dbg(chan, "DMA controller still busy\n");
 586                return;
 587        }
 588
 589        /*
 590         * If there are some link descriptors which have not been
 591         * transferred, we need to start the controller
 592         */
 593
 594        /*
 595         * Move all elements from the queue of pending transactions
 596         * onto the list of running transactions
 597         */
 598        chan_dbg(chan, "idle, starting controller\n");
 599        desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node);
 600        list_splice_tail_init(&chan->ld_pending, &chan->ld_running);
 601
 602        /*
 603         * The 85xx DMA controller doesn't clear the channel start bit
 604         * automatically at the end of a transfer. Therefore we must clear
 605         * it in software before starting the transfer.
 606         */
 607        if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
 608                u32 mode;
 609
 610                mode = get_mr(chan);
 611                mode &= ~FSL_DMA_MR_CS;
 612                set_mr(chan, mode);
 613        }
 614
 615        /*
 616         * Program the descriptor's address into the DMA controller,
 617         * then start the DMA transaction
 618         */
 619        set_cdar(chan, desc->async_tx.phys);
 620        get_cdar(chan);
 621
 622        dma_start(chan);
 623        chan->idle = false;
 624}
 625
 626/**
 627 * fsldma_cleanup_descriptors - cleanup link descriptors which are completed
 628 * and move them to ld_completed to free until flag 'ack' is set
 629 * @chan: Freescale DMA channel
 630 *
 631 * This function is used on descriptors which have been executed by the DMA
 632 * controller. It will run any callbacks, submit any dependencies, then
 633 * free these descriptors if flag 'ack' is set.
 634 */
 635static void fsldma_cleanup_descriptors(struct fsldma_chan *chan)
 636{
 637        struct fsl_desc_sw *desc, *_desc;
 638        dma_cookie_t cookie = 0;
 639        dma_addr_t curr_phys = get_cdar(chan);
 640        int seen_current = 0;
 641
 642        fsldma_clean_completed_descriptor(chan);
 643
 644        /* Run the callback for each descriptor, in order */
 645        list_for_each_entry_safe(desc, _desc, &chan->ld_running, node) {
 646                /*
 647                 * do not advance past the current descriptor loaded into the
 648                 * hardware channel, subsequent descriptors are either in
 649                 * process or have not been submitted
 650                 */
 651                if (seen_current)
 652                        break;
 653
 654                /*
 655                 * stop the search if we reach the current descriptor and the
 656                 * channel is busy
 657                 */
 658                if (desc->async_tx.phys == curr_phys) {
 659                        seen_current = 1;
 660                        if (!dma_is_idle(chan))
 661                                break;
 662                }
 663
 664                cookie = fsldma_run_tx_complete_actions(chan, desc, cookie);
 665
 666                fsldma_clean_running_descriptor(chan, desc);
 667        }
 668
 669        /*
 670         * Start any pending transactions automatically
 671         *
 672         * In the ideal case, we keep the DMA controller busy while we go
 673         * ahead and free the descriptors below.
 674         */
 675        fsl_chan_xfer_ld_queue(chan);
 676
 677        if (cookie > 0)
 678                chan->common.completed_cookie = cookie;
 679}
 680
 681/**
 682 * fsl_dma_alloc_chan_resources - Allocate resources for DMA channel.
 683 * @chan : Freescale DMA channel
 684 *
 685 * This function will create a dma pool for descriptor allocation.
 686 *
 687 * Return - The number of descriptors allocated.
 688 */
 689static int fsl_dma_alloc_chan_resources(struct dma_chan *dchan)
 690{
 691        struct fsldma_chan *chan = to_fsl_chan(dchan);
 692
 693        /* Has this channel already been allocated? */
 694        if (chan->desc_pool)
 695                return 1;
 696
 697        /*
 698         * We need the descriptor to be aligned to 32bytes
 699         * for meeting FSL DMA specification requirement.
 700         */
 701        chan->desc_pool = dma_pool_create(chan->name, chan->dev,
 702                                          sizeof(struct fsl_desc_sw),
 703                                          __alignof__(struct fsl_desc_sw), 0);
 704        if (!chan->desc_pool) {
 705                chan_err(chan, "unable to allocate descriptor pool\n");
 706                return -ENOMEM;
 707        }
 708
 709        /* there is at least one descriptor free to be allocated */
 710        return 1;
 711}
 712
 713/**
 714 * fsldma_free_desc_list - Free all descriptors in a queue
 715 * @chan: Freescae DMA channel
 716 * @list: the list to free
 717 *
 718 * LOCKING: must hold chan->desc_lock
 719 */
 720static void fsldma_free_desc_list(struct fsldma_chan *chan,
 721                                  struct list_head *list)
 722{
 723        struct fsl_desc_sw *desc, *_desc;
 724
 725        list_for_each_entry_safe(desc, _desc, list, node)
 726                fsl_dma_free_descriptor(chan, desc);
 727}
 728
 729static void fsldma_free_desc_list_reverse(struct fsldma_chan *chan,
 730                                          struct list_head *list)
 731{
 732        struct fsl_desc_sw *desc, *_desc;
 733
 734        list_for_each_entry_safe_reverse(desc, _desc, list, node)
 735                fsl_dma_free_descriptor(chan, desc);
 736}
 737
 738/**
 739 * fsl_dma_free_chan_resources - Free all resources of the channel.
 740 * @chan : Freescale DMA channel
 741 */
 742static void fsl_dma_free_chan_resources(struct dma_chan *dchan)
 743{
 744        struct fsldma_chan *chan = to_fsl_chan(dchan);
 745
 746        chan_dbg(chan, "free all channel resources\n");
 747        spin_lock_bh(&chan->desc_lock);
 748        fsldma_cleanup_descriptors(chan);
 749        fsldma_free_desc_list(chan, &chan->ld_pending);
 750        fsldma_free_desc_list(chan, &chan->ld_running);
 751        fsldma_free_desc_list(chan, &chan->ld_completed);
 752        spin_unlock_bh(&chan->desc_lock);
 753
 754        dma_pool_destroy(chan->desc_pool);
 755        chan->desc_pool = NULL;
 756}
 757
 758static struct dma_async_tx_descriptor *
 759fsl_dma_prep_memcpy(struct dma_chan *dchan,
 760        dma_addr_t dma_dst, dma_addr_t dma_src,
 761        size_t len, unsigned long flags)
 762{
 763        struct fsldma_chan *chan;
 764        struct fsl_desc_sw *first = NULL, *prev = NULL, *new;
 765        size_t copy;
 766
 767        if (!dchan)
 768                return NULL;
 769
 770        if (!len)
 771                return NULL;
 772
 773        chan = to_fsl_chan(dchan);
 774
 775        do {
 776
 777                /* Allocate the link descriptor from DMA pool */
 778                new = fsl_dma_alloc_descriptor(chan);
 779                if (!new) {
 780                        chan_err(chan, "%s\n", msg_ld_oom);
 781                        goto fail;
 782                }
 783
 784                copy = min(len, (size_t)FSL_DMA_BCR_MAX_CNT);
 785
 786                set_desc_cnt(chan, &new->hw, copy);
 787                set_desc_src(chan, &new->hw, dma_src);
 788                set_desc_dst(chan, &new->hw, dma_dst);
 789
 790                if (!first)
 791                        first = new;
 792                else
 793                        set_desc_next(chan, &prev->hw, new->async_tx.phys);
 794
 795                new->async_tx.cookie = 0;
 796                async_tx_ack(&new->async_tx);
 797
 798                prev = new;
 799                len -= copy;
 800                dma_src += copy;
 801                dma_dst += copy;
 802
 803                /* Insert the link descriptor to the LD ring */
 804                list_add_tail(&new->node, &first->tx_list);
 805        } while (len);
 806
 807        new->async_tx.flags = flags; /* client is in control of this ack */
 808        new->async_tx.cookie = -EBUSY;
 809
 810        /* Set End-of-link to the last link descriptor of new list */
 811        set_ld_eol(chan, new);
 812
 813        return &first->async_tx;
 814
 815fail:
 816        if (!first)
 817                return NULL;
 818
 819        fsldma_free_desc_list_reverse(chan, &first->tx_list);
 820        return NULL;
 821}
 822
 823static int fsl_dma_device_terminate_all(struct dma_chan *dchan)
 824{
 825        struct fsldma_chan *chan;
 826
 827        if (!dchan)
 828                return -EINVAL;
 829
 830        chan = to_fsl_chan(dchan);
 831
 832        spin_lock_bh(&chan->desc_lock);
 833
 834        /* Halt the DMA engine */
 835        dma_halt(chan);
 836
 837        /* Remove and free all of the descriptors in the LD queue */
 838        fsldma_free_desc_list(chan, &chan->ld_pending);
 839        fsldma_free_desc_list(chan, &chan->ld_running);
 840        fsldma_free_desc_list(chan, &chan->ld_completed);
 841        chan->idle = true;
 842
 843        spin_unlock_bh(&chan->desc_lock);
 844        return 0;
 845}
 846
 847static int fsl_dma_device_config(struct dma_chan *dchan,
 848                                 struct dma_slave_config *config)
 849{
 850        struct fsldma_chan *chan;
 851        int size;
 852
 853        if (!dchan)
 854                return -EINVAL;
 855
 856        chan = to_fsl_chan(dchan);
 857
 858        /* make sure the channel supports setting burst size */
 859        if (!chan->set_request_count)
 860                return -ENXIO;
 861
 862        /* we set the controller burst size depending on direction */
 863        if (config->direction == DMA_MEM_TO_DEV)
 864                size = config->dst_addr_width * config->dst_maxburst;
 865        else
 866                size = config->src_addr_width * config->src_maxburst;
 867
 868        chan->set_request_count(chan, size);
 869        return 0;
 870}
 871
 872
 873/**
 874 * fsl_dma_memcpy_issue_pending - Issue the DMA start command
 875 * @chan : Freescale DMA channel
 876 */
 877static void fsl_dma_memcpy_issue_pending(struct dma_chan *dchan)
 878{
 879        struct fsldma_chan *chan = to_fsl_chan(dchan);
 880
 881        spin_lock_bh(&chan->desc_lock);
 882        fsl_chan_xfer_ld_queue(chan);
 883        spin_unlock_bh(&chan->desc_lock);
 884}
 885
 886/**
 887 * fsl_tx_status - Determine the DMA status
 888 * @chan : Freescale DMA channel
 889 */
 890static enum dma_status fsl_tx_status(struct dma_chan *dchan,
 891                                        dma_cookie_t cookie,
 892                                        struct dma_tx_state *txstate)
 893{
 894        struct fsldma_chan *chan = to_fsl_chan(dchan);
 895        enum dma_status ret;
 896
 897        ret = dma_cookie_status(dchan, cookie, txstate);
 898        if (ret == DMA_COMPLETE)
 899                return ret;
 900
 901        spin_lock_bh(&chan->desc_lock);
 902        fsldma_cleanup_descriptors(chan);
 903        spin_unlock_bh(&chan->desc_lock);
 904
 905        return dma_cookie_status(dchan, cookie, txstate);
 906}
 907
 908/*----------------------------------------------------------------------------*/
 909/* Interrupt Handling                                                         */
 910/*----------------------------------------------------------------------------*/
 911
 912static irqreturn_t fsldma_chan_irq(int irq, void *data)
 913{
 914        struct fsldma_chan *chan = data;
 915        u32 stat;
 916
 917        /* save and clear the status register */
 918        stat = get_sr(chan);
 919        set_sr(chan, stat);
 920        chan_dbg(chan, "irq: stat = 0x%x\n", stat);
 921
 922        /* check that this was really our device */
 923        stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH);
 924        if (!stat)
 925                return IRQ_NONE;
 926
 927        if (stat & FSL_DMA_SR_TE)
 928                chan_err(chan, "Transfer Error!\n");
 929
 930        /*
 931         * Programming Error
 932         * The DMA_INTERRUPT async_tx is a NULL transfer, which will
 933         * trigger a PE interrupt.
 934         */
 935        if (stat & FSL_DMA_SR_PE) {
 936                chan_dbg(chan, "irq: Programming Error INT\n");
 937                stat &= ~FSL_DMA_SR_PE;
 938                if (get_bcr(chan) != 0)
 939                        chan_err(chan, "Programming Error!\n");
 940        }
 941
 942        /*
 943         * For MPC8349, EOCDI event need to update cookie
 944         * and start the next transfer if it exist.
 945         */
 946        if (stat & FSL_DMA_SR_EOCDI) {
 947                chan_dbg(chan, "irq: End-of-Chain link INT\n");
 948                stat &= ~FSL_DMA_SR_EOCDI;
 949        }
 950
 951        /*
 952         * If it current transfer is the end-of-transfer,
 953         * we should clear the Channel Start bit for
 954         * prepare next transfer.
 955         */
 956        if (stat & FSL_DMA_SR_EOLNI) {
 957                chan_dbg(chan, "irq: End-of-link INT\n");
 958                stat &= ~FSL_DMA_SR_EOLNI;
 959        }
 960
 961        /* check that the DMA controller is really idle */
 962        if (!dma_is_idle(chan))
 963                chan_err(chan, "irq: controller not idle!\n");
 964
 965        /* check that we handled all of the bits */
 966        if (stat)
 967                chan_err(chan, "irq: unhandled sr 0x%08x\n", stat);
 968
 969        /*
 970         * Schedule the tasklet to handle all cleanup of the current
 971         * transaction. It will start a new transaction if there is
 972         * one pending.
 973         */
 974        tasklet_schedule(&chan->tasklet);
 975        chan_dbg(chan, "irq: Exit\n");
 976        return IRQ_HANDLED;
 977}
 978
 979static void dma_do_tasklet(unsigned long data)
 980{
 981        struct fsldma_chan *chan = (struct fsldma_chan *)data;
 982
 983        chan_dbg(chan, "tasklet entry\n");
 984
 985        spin_lock(&chan->desc_lock);
 986
 987        /* the hardware is now idle and ready for more */
 988        chan->idle = true;
 989
 990        /* Run all cleanup for descriptors which have been completed */
 991        fsldma_cleanup_descriptors(chan);
 992
 993        spin_unlock(&chan->desc_lock);
 994
 995        chan_dbg(chan, "tasklet exit\n");
 996}
 997
 998static irqreturn_t fsldma_ctrl_irq(int irq, void *data)
 999{
1000        struct fsldma_device *fdev = data;
1001        struct fsldma_chan *chan;
1002        unsigned int handled = 0;
1003        u32 gsr, mask;
1004        int i;
1005
1006        gsr = (fdev->feature & FSL_DMA_BIG_ENDIAN) ? in_be32(fdev->regs)
1007                                                   : in_le32(fdev->regs);
1008        mask = 0xff000000;
1009        dev_dbg(fdev->dev, "IRQ: gsr 0x%.8x\n", gsr);
1010
1011        for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1012                chan = fdev->chan[i];
1013                if (!chan)
1014                        continue;
1015
1016                if (gsr & mask) {
1017                        dev_dbg(fdev->dev, "IRQ: chan %d\n", chan->id);
1018                        fsldma_chan_irq(irq, chan);
1019                        handled++;
1020                }
1021
1022                gsr &= ~mask;
1023                mask >>= 8;
1024        }
1025
1026        return IRQ_RETVAL(handled);
1027}
1028
1029static void fsldma_free_irqs(struct fsldma_device *fdev)
1030{
1031        struct fsldma_chan *chan;
1032        int i;
1033
1034        if (fdev->irq) {
1035                dev_dbg(fdev->dev, "free per-controller IRQ\n");
1036                free_irq(fdev->irq, fdev);
1037                return;
1038        }
1039
1040        for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1041                chan = fdev->chan[i];
1042                if (chan && chan->irq) {
1043                        chan_dbg(chan, "free per-channel IRQ\n");
1044                        free_irq(chan->irq, chan);
1045                }
1046        }
1047}
1048
1049static int fsldma_request_irqs(struct fsldma_device *fdev)
1050{
1051        struct fsldma_chan *chan;
1052        int ret;
1053        int i;
1054
1055        /* if we have a per-controller IRQ, use that */
1056        if (fdev->irq) {
1057                dev_dbg(fdev->dev, "request per-controller IRQ\n");
1058                ret = request_irq(fdev->irq, fsldma_ctrl_irq, IRQF_SHARED,
1059                                  "fsldma-controller", fdev);
1060                return ret;
1061        }
1062
1063        /* no per-controller IRQ, use the per-channel IRQs */
1064        for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1065                chan = fdev->chan[i];
1066                if (!chan)
1067                        continue;
1068
1069                if (!chan->irq) {
1070                        chan_err(chan, "interrupts property missing in device tree\n");
1071                        ret = -ENODEV;
1072                        goto out_unwind;
1073                }
1074
1075                chan_dbg(chan, "request per-channel IRQ\n");
1076                ret = request_irq(chan->irq, fsldma_chan_irq, IRQF_SHARED,
1077                                  "fsldma-chan", chan);
1078                if (ret) {
1079                        chan_err(chan, "unable to request per-channel IRQ\n");
1080                        goto out_unwind;
1081                }
1082        }
1083
1084        return 0;
1085
1086out_unwind:
1087        for (/* none */; i >= 0; i--) {
1088                chan = fdev->chan[i];
1089                if (!chan)
1090                        continue;
1091
1092                if (!chan->irq)
1093                        continue;
1094
1095                free_irq(chan->irq, chan);
1096        }
1097
1098        return ret;
1099}
1100
1101/*----------------------------------------------------------------------------*/
1102/* OpenFirmware Subsystem                                                     */
1103/*----------------------------------------------------------------------------*/
1104
1105static int fsl_dma_chan_probe(struct fsldma_device *fdev,
1106        struct device_node *node, u32 feature, const char *compatible)
1107{
1108        struct fsldma_chan *chan;
1109        struct resource res;
1110        int err;
1111
1112        /* alloc channel */
1113        chan = kzalloc(sizeof(*chan), GFP_KERNEL);
1114        if (!chan) {
1115                err = -ENOMEM;
1116                goto out_return;
1117        }
1118
1119        /* ioremap registers for use */
1120        chan->regs = of_iomap(node, 0);
1121        if (!chan->regs) {
1122                dev_err(fdev->dev, "unable to ioremap registers\n");
1123                err = -ENOMEM;
1124                goto out_free_chan;
1125        }
1126
1127        err = of_address_to_resource(node, 0, &res);
1128        if (err) {
1129                dev_err(fdev->dev, "unable to find 'reg' property\n");
1130                goto out_iounmap_regs;
1131        }
1132
1133        chan->feature = feature;
1134        if (!fdev->feature)
1135                fdev->feature = chan->feature;
1136
1137        /*
1138         * If the DMA device's feature is different than the feature
1139         * of its channels, report the bug
1140         */
1141        WARN_ON(fdev->feature != chan->feature);
1142
1143        chan->dev = fdev->dev;
1144        chan->id = (res.start & 0xfff) < 0x300 ?
1145                   ((res.start - 0x100) & 0xfff) >> 7 :
1146                   ((res.start - 0x200) & 0xfff) >> 7;
1147        if (chan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) {
1148                dev_err(fdev->dev, "too many channels for device\n");
1149                err = -EINVAL;
1150                goto out_iounmap_regs;
1151        }
1152
1153        fdev->chan[chan->id] = chan;
1154        tasklet_init(&chan->tasklet, dma_do_tasklet, (unsigned long)chan);
1155        snprintf(chan->name, sizeof(chan->name), "chan%d", chan->id);
1156
1157        /* Initialize the channel */
1158        dma_init(chan);
1159
1160        /* Clear cdar registers */
1161        set_cdar(chan, 0);
1162
1163        switch (chan->feature & FSL_DMA_IP_MASK) {
1164        case FSL_DMA_IP_85XX:
1165                chan->toggle_ext_pause = fsl_chan_toggle_ext_pause;
1166        case FSL_DMA_IP_83XX:
1167                chan->toggle_ext_start = fsl_chan_toggle_ext_start;
1168                chan->set_src_loop_size = fsl_chan_set_src_loop_size;
1169                chan->set_dst_loop_size = fsl_chan_set_dst_loop_size;
1170                chan->set_request_count = fsl_chan_set_request_count;
1171        }
1172
1173        spin_lock_init(&chan->desc_lock);
1174        INIT_LIST_HEAD(&chan->ld_pending);
1175        INIT_LIST_HEAD(&chan->ld_running);
1176        INIT_LIST_HEAD(&chan->ld_completed);
1177        chan->idle = true;
1178#ifdef CONFIG_PM
1179        chan->pm_state = RUNNING;
1180#endif
1181
1182        chan->common.device = &fdev->common;
1183        dma_cookie_init(&chan->common);
1184
1185        /* find the IRQ line, if it exists in the device tree */
1186        chan->irq = irq_of_parse_and_map(node, 0);
1187
1188        /* Add the channel to DMA device channel list */
1189        list_add_tail(&chan->common.device_node, &fdev->common.channels);
1190
1191        dev_info(fdev->dev, "#%d (%s), irq %d\n", chan->id, compatible,
1192                 chan->irq ? chan->irq : fdev->irq);
1193
1194        return 0;
1195
1196out_iounmap_regs:
1197        iounmap(chan->regs);
1198out_free_chan:
1199        kfree(chan);
1200out_return:
1201        return err;
1202}
1203
1204static void fsl_dma_chan_remove(struct fsldma_chan *chan)
1205{
1206        irq_dispose_mapping(chan->irq);
1207        list_del(&chan->common.device_node);
1208        iounmap(chan->regs);
1209        kfree(chan);
1210}
1211
1212static int fsldma_of_probe(struct platform_device *op)
1213{
1214        struct fsldma_device *fdev;
1215        struct device_node *child;
1216        int err;
1217
1218        fdev = kzalloc(sizeof(*fdev), GFP_KERNEL);
1219        if (!fdev) {
1220                err = -ENOMEM;
1221                goto out_return;
1222        }
1223
1224        fdev->dev = &op->dev;
1225        INIT_LIST_HEAD(&fdev->common.channels);
1226
1227        /* ioremap the registers for use */
1228        fdev->regs = of_iomap(op->dev.of_node, 0);
1229        if (!fdev->regs) {
1230                dev_err(&op->dev, "unable to ioremap registers\n");
1231                err = -ENOMEM;
1232                goto out_free;
1233        }
1234
1235        /* map the channel IRQ if it exists, but don't hookup the handler yet */
1236        fdev->irq = irq_of_parse_and_map(op->dev.of_node, 0);
1237
1238        dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
1239        dma_cap_set(DMA_SLAVE, fdev->common.cap_mask);
1240        fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources;
1241        fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources;
1242        fdev->common.device_prep_dma_memcpy = fsl_dma_prep_memcpy;
1243        fdev->common.device_tx_status = fsl_tx_status;
1244        fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending;
1245        fdev->common.device_config = fsl_dma_device_config;
1246        fdev->common.device_terminate_all = fsl_dma_device_terminate_all;
1247        fdev->common.dev = &op->dev;
1248
1249        fdev->common.src_addr_widths = FSL_DMA_BUSWIDTHS;
1250        fdev->common.dst_addr_widths = FSL_DMA_BUSWIDTHS;
1251        fdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1252        fdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1253
1254        dma_set_mask(&(op->dev), DMA_BIT_MASK(36));
1255
1256        platform_set_drvdata(op, fdev);
1257
1258        /*
1259         * We cannot use of_platform_bus_probe() because there is no
1260         * of_platform_bus_remove(). Instead, we manually instantiate every DMA
1261         * channel object.
1262         */
1263        for_each_child_of_node(op->dev.of_node, child) {
1264                if (of_device_is_compatible(child, "fsl,eloplus-dma-channel")) {
1265                        fsl_dma_chan_probe(fdev, child,
1266                                FSL_DMA_IP_85XX | FSL_DMA_BIG_ENDIAN,
1267                                "fsl,eloplus-dma-channel");
1268                }
1269
1270                if (of_device_is_compatible(child, "fsl,elo-dma-channel")) {
1271                        fsl_dma_chan_probe(fdev, child,
1272                                FSL_DMA_IP_83XX | FSL_DMA_LITTLE_ENDIAN,
1273                                "fsl,elo-dma-channel");
1274                }
1275        }
1276
1277        /*
1278         * Hookup the IRQ handler(s)
1279         *
1280         * If we have a per-controller interrupt, we prefer that to the
1281         * per-channel interrupts to reduce the number of shared interrupt
1282         * handlers on the same IRQ line
1283         */
1284        err = fsldma_request_irqs(fdev);
1285        if (err) {
1286                dev_err(fdev->dev, "unable to request IRQs\n");
1287                goto out_free_fdev;
1288        }
1289
1290        dma_async_device_register(&fdev->common);
1291        return 0;
1292
1293out_free_fdev:
1294        irq_dispose_mapping(fdev->irq);
1295        iounmap(fdev->regs);
1296out_free:
1297        kfree(fdev);
1298out_return:
1299        return err;
1300}
1301
1302static int fsldma_of_remove(struct platform_device *op)
1303{
1304        struct fsldma_device *fdev;
1305        unsigned int i;
1306
1307        fdev = platform_get_drvdata(op);
1308        dma_async_device_unregister(&fdev->common);
1309
1310        fsldma_free_irqs(fdev);
1311
1312        for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1313                if (fdev->chan[i])
1314                        fsl_dma_chan_remove(fdev->chan[i]);
1315        }
1316
1317        iounmap(fdev->regs);
1318        kfree(fdev);
1319
1320        return 0;
1321}
1322
1323#ifdef CONFIG_PM
1324static int fsldma_suspend_late(struct device *dev)
1325{
1326        struct fsldma_device *fdev = dev_get_drvdata(dev);
1327        struct fsldma_chan *chan;
1328        int i;
1329
1330        for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1331                chan = fdev->chan[i];
1332                if (!chan)
1333                        continue;
1334
1335                spin_lock_bh(&chan->desc_lock);
1336                if (unlikely(!chan->idle))
1337                        goto out;
1338                chan->regs_save.mr = get_mr(chan);
1339                chan->pm_state = SUSPENDED;
1340                spin_unlock_bh(&chan->desc_lock);
1341        }
1342        return 0;
1343
1344out:
1345        for (; i >= 0; i--) {
1346                chan = fdev->chan[i];
1347                if (!chan)
1348                        continue;
1349                chan->pm_state = RUNNING;
1350                spin_unlock_bh(&chan->desc_lock);
1351        }
1352        return -EBUSY;
1353}
1354
1355static int fsldma_resume_early(struct device *dev)
1356{
1357        struct fsldma_device *fdev = dev_get_drvdata(dev);
1358        struct fsldma_chan *chan;
1359        u32 mode;
1360        int i;
1361
1362        for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
1363                chan = fdev->chan[i];
1364                if (!chan)
1365                        continue;
1366
1367                spin_lock_bh(&chan->desc_lock);
1368                mode = chan->regs_save.mr
1369                        & ~FSL_DMA_MR_CS & ~FSL_DMA_MR_CC & ~FSL_DMA_MR_CA;
1370                set_mr(chan, mode);
1371                chan->pm_state = RUNNING;
1372                spin_unlock_bh(&chan->desc_lock);
1373        }
1374
1375        return 0;
1376}
1377
1378static const struct dev_pm_ops fsldma_pm_ops = {
1379        .suspend_late   = fsldma_suspend_late,
1380        .resume_early   = fsldma_resume_early,
1381};
1382#endif
1383
1384static const struct of_device_id fsldma_of_ids[] = {
1385        { .compatible = "fsl,elo3-dma", },
1386        { .compatible = "fsl,eloplus-dma", },
1387        { .compatible = "fsl,elo-dma", },
1388        {}
1389};
1390MODULE_DEVICE_TABLE(of, fsldma_of_ids);
1391
1392static struct platform_driver fsldma_of_driver = {
1393        .driver = {
1394                .name = "fsl-elo-dma",
1395                .of_match_table = fsldma_of_ids,
1396#ifdef CONFIG_PM
1397                .pm = &fsldma_pm_ops,
1398#endif
1399        },
1400        .probe = fsldma_of_probe,
1401        .remove = fsldma_of_remove,
1402};
1403
1404/*----------------------------------------------------------------------------*/
1405/* Module Init / Exit                                                         */
1406/*----------------------------------------------------------------------------*/
1407
1408static __init int fsldma_init(void)
1409{
1410        pr_info("Freescale Elo series DMA driver\n");
1411        return platform_driver_register(&fsldma_of_driver);
1412}
1413
1414static void __exit fsldma_exit(void)
1415{
1416        platform_driver_unregister(&fsldma_of_driver);
1417}
1418
1419subsys_initcall(fsldma_init);
1420module_exit(fsldma_exit);
1421
1422MODULE_DESCRIPTION("Freescale Elo series DMA driver");
1423MODULE_LICENSE("GPL");
1424