drivers/dma/dw_dmac.c

   1 /*
   2  * Core driver for the Synopsys DesignWare DMA Controller
   3  *
   4  * Copyright (C) 2007-2008 Atmel Corporation
   5  * Copyright (C) 2010-2011 ST Microelectronics
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/bitops.h>
  13 #include <linux/clk.h>
  14 #include <linux/delay.h>
  15 #include <linux/dmaengine.h>
  16 #include <linux/dma-mapping.h>
  17 #include <linux/dmapool.h>
  18 #include <linux/err.h>
  19 #include <linux/init.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/io.h>
  22 #include <linux/of.h>
  23 #include <linux/of_dma.h>
  24 #include <linux/mm.h>
  25 #include <linux/module.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/slab.h>
  28
  29 #include "dw_dmac_regs.h"
  30 #include "dmaengine.h"
  31
  32 /*
  33  * This supports the Synopsys "DesignWare AHB Central DMA Controller",
  34  * (DW_ahb_dmac) which is used with various AMBA 2.0 systems (not all
  35  * of which use ARM any more).  See the "Databook" from Synopsys for
  36  * information beyond what licensees probably provide.
  37  *
  38  * The driver has currently been tested only with the Atmel AT32AP7000,
  39  * which does not support descriptor writeback.
  40  */
  41
  42 static inline unsigned int dwc_get_dms(struct dw_dma_slave *slave)
  43 {
  44         return slave ? slave->dst_master : 0;
  45 }
  46
  47 static inline unsigned int dwc_get_sms(struct dw_dma_slave *slave)
  48 {
  49         return slave ? slave->src_master : 1;
  50 }
  51
  52 #define SRC_MASTER      0
  53 #define DST_MASTER      1
  54
  55 static inline unsigned int dwc_get_master(struct dma_chan *chan, int master)
  56 {
  57         struct dw_dma *dw = to_dw_dma(chan->device);
  58         struct dw_dma_slave *dws = chan->private;
  59         unsigned int m;
  60
  61         if (master == SRC_MASTER)
  62                 m = dwc_get_sms(dws);
  63         else
  64                 m = dwc_get_dms(dws);
  65
  66         return min_t(unsigned int, dw->nr_masters - 1, m);
  67 }
  68
  69 #define DWC_DEFAULT_CTLLO(_chan) ({                             \
  70                 struct dw_dma_chan *_dwc = to_dw_dma_chan(_chan);       \
  71                 struct dma_slave_config *_sconfig = &_dwc->dma_sconfig; \
  72                 bool _is_slave = is_slave_direction(_dwc->direction);   \
  73                 int _dms = dwc_get_master(_chan, DST_MASTER);           \
  74                 int _sms = dwc_get_master(_chan, SRC_MASTER);           \
  75                 u8 _smsize = _is_slave ? _sconfig->src_maxburst :       \
  76                         DW_DMA_MSIZE_16;                        \
  77                 u8 _dmsize = _is_slave ? _sconfig->dst_maxburst :       \
  78                         DW_DMA_MSIZE_16;                        \
  79                                                                 \
  80                 (DWC_CTLL_DST_MSIZE(_dmsize)                    \
  81                  | DWC_CTLL_SRC_MSIZE(_smsize)                  \
  82                  | DWC_CTLL_LLP_D_EN                            \
  83                  | DWC_CTLL_LLP_S_EN                            \
  84                  | DWC_CTLL_DMS(_dms)                           \
  85                  | DWC_CTLL_SMS(_sms));                         \
  86         })
  87
  88 /*
  89  * Number of descriptors to allocate for each channel. This should be
  90  * made configurable somehow; preferably, the clients (at least the
  91  * ones using slave transfers) should be able to give us a hint.
  92  */
  93 #define NR_DESCS_PER_CHANNEL    64
  94
  95 static inline unsigned int dwc_get_data_width(struct dma_chan *chan, int master)
  96 {
  97         struct dw_dma *dw = to_dw_dma(chan->device);
  98
  99         return dw->data_width[dwc_get_master(chan, master)];
 100 }
 101
 102 /*----------------------------------------------------------------------*/
 103
 104 static struct device *chan2dev(struct dma_chan *chan)
 105 {
 106         return &chan->dev->device;
 107 }
 108 static struct device *chan2parent(struct dma_chan *chan)
 109 {
 110         return chan->dev->device.parent;
 111 }
 112
 113 static struct dw_desc *dwc_first_active(struct dw_dma_chan *dwc)
 114 {
 115         return to_dw_desc(dwc->active_list.next);
 116 }
 117
 118 static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc)
 119 {
 120         struct dw_desc *desc, *_desc;
 121         struct dw_desc *ret = NULL;
 122         unsigned int i = 0;
 123         unsigned long flags;
 124
 125         spin_lock_irqsave(&dwc->lock, flags);
 126         list_for_each_entry_safe(desc, _desc, &dwc->free_list, desc_node) {
 127                 i++;
 128                 if (async_tx_test_ack(&desc->txd)) {
 129                         list_del(&desc->desc_node);
 130                         ret = desc;
 131                         break;
 132                 }
 133                 dev_dbg(chan2dev(&dwc->chan), "desc %p not ACKed\n", desc);
 134         }
 135         spin_unlock_irqrestore(&dwc->lock, flags);
 136
 137         dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i);
 138
 139         return ret;
 140 }
 141
 142 /*
 143  * Move a descriptor, including any children, to the free list.
 144  * `desc' must not be on any lists.
 145  */
 146 static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
 147 {
 148         unsigned long flags;
 149
 150         if (desc) {
 151                 struct dw_desc *child;
 152
 153                 spin_lock_irqsave(&dwc->lock, flags);
 154                 list_for_each_entry(child, &desc->tx_list, desc_node)
 155                         dev_vdbg(chan2dev(&dwc->chan),
 156                                         "moving child desc %p to freelist\n",
 157                                         child);
 158                 list_splice_init(&desc->tx_list, &dwc->free_list);
 159                 dev_vdbg(chan2dev(&dwc->chan), "moving desc %p to freelist\n", desc);
 160                 list_add(&desc->desc_node, &dwc->free_list);
 161                 spin_unlock_irqrestore(&dwc->lock, flags);
 162         }
 163 }
 164
 165 static void dwc_initialize(struct dw_dma_chan *dwc)
 166 {
 167         struct dw_dma *dw = to_dw_dma(dwc->chan.device);
 168         struct dw_dma_slave *dws = dwc->chan.private;
 169         u32 cfghi = DWC_CFGH_FIFO_MODE;
 170         u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
 171
 172         if (dwc->initialized == true)
 173                 return;
 174
 175         if (dws && dws->cfg_hi == ~0 && dws->cfg_lo == ~0) {
 176                 /* autoconfigure based on request line from DT */
 177                 if (dwc->direction == DMA_MEM_TO_DEV)
 178                         cfghi = DWC_CFGH_DST_PER(dwc->request_line);
 179                 else if (dwc->direction == DMA_DEV_TO_MEM)
 180                         cfghi = DWC_CFGH_SRC_PER(dwc->request_line);
 181         } else if (dws) {
 182                 /*
 183                  * We need controller-specific data to set up slave
 184                  * transfers.
 185                  */
 186                 BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev);
 187
 188                 cfghi = dws->cfg_hi;
 189                 cfglo |= dws->cfg_lo & ~DWC_CFGL_CH_PRIOR_MASK;
 190         } else {
 191                 if (dwc->direction == DMA_MEM_TO_DEV)
 192                         cfghi = DWC_CFGH_DST_PER(dwc->dma_sconfig.slave_id);
 193                 else if (dwc->direction == DMA_DEV_TO_MEM)
 194                         cfghi = DWC_CFGH_SRC_PER(dwc->dma_sconfig.slave_id);
 195         }
 196
 197         channel_writel(dwc, CFG_LO, cfglo);
 198         channel_writel(dwc, CFG_HI, cfghi);
 199
 200         /* Enable interrupts */
 201         channel_set_bit(dw, MASK.XFER, dwc->mask);
 202         channel_set_bit(dw, MASK.ERROR, dwc->mask);
 203
 204         dwc->initialized = true;
 205 }
 206
 207 /*----------------------------------------------------------------------*/
 208
 209 static inline unsigned int dwc_fast_fls(unsigned long long v)
 210 {
 211         /*
 212          * We can be a lot more clever here, but this should take care
 213          * of the most common optimization.
 214          */
 215         if (!(v & 7))
 216                 return 3;
 217         else if (!(v & 3))
 218                 return 2;
 219         else if (!(v & 1))
 220                 return 1;
 221         return 0;
 222 }
 223
 224 static inline void dwc_dump_chan_regs(struct dw_dma_chan *dwc)
 225 {
 226         dev_err(chan2dev(&dwc->chan),
 227                 "  SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
 228                 channel_readl(dwc, SAR),
 229                 channel_readl(dwc, DAR),
 230                 channel_readl(dwc, LLP),
 231                 channel_readl(dwc, CTL_HI),
 232                 channel_readl(dwc, CTL_LO));
 233 }
 234
 235 static inline void dwc_chan_disable(struct dw_dma *dw, struct dw_dma_chan *dwc)
 236 {
 237         channel_clear_bit(dw, CH_EN, dwc->mask);
 238         while (dma_readl(dw, CH_EN) & dwc->mask)
 239                 cpu_relax();
 240 }
 241
 242 /*----------------------------------------------------------------------*/
 243
 244 /* Perform single block transfer */
 245 static inline void dwc_do_single_block(struct dw_dma_chan *dwc,
 246                                        struct dw_desc *desc)
 247 {
 248         struct dw_dma   *dw = to_dw_dma(dwc->chan.device);
 249         u32             ctllo;
 250
 251         /* Software emulation of LLP mode relies on interrupts to continue
 252          * multi block transfer. */
 253         ctllo = desc->lli.ctllo | DWC_CTLL_INT_EN;
 254
 255         channel_writel(dwc, SAR, desc->lli.sar);
 256         channel_writel(dwc, DAR, desc->lli.dar);
 257         channel_writel(dwc, CTL_LO, ctllo);
 258         channel_writel(dwc, CTL_HI, desc->lli.ctlhi);
 259         channel_set_bit(dw, CH_EN, dwc->mask);
 260
 261         /* Move pointer to next descriptor */
 262         dwc->tx_node_active = dwc->tx_node_active->next;
 263 }
 264
 265 /* Called with dwc->lock held and bh disabled */
 266 static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
 267 {
 268         struct dw_dma   *dw = to_dw_dma(dwc->chan.device);
 269         unsigned long   was_soft_llp;
 270
 271         /* ASSERT:  channel is idle */
 272         if (dma_readl(dw, CH_EN) & dwc->mask) {
 273                 dev_err(chan2dev(&dwc->chan),
 274                         "BUG: Attempted to start non-idle channel\n");
 275                 dwc_dump_chan_regs(dwc);
 276
 277                 /* The tasklet will hopefully advance the queue... */
 278                 return;
 279         }
 280
 281         if (dwc->nollp) {
 282                 was_soft_llp = test_and_set_bit(DW_DMA_IS_SOFT_LLP,
 283                                                 &dwc->flags);
 284                 if (was_soft_llp) {
 285                         dev_err(chan2dev(&dwc->chan),
 286                                 "BUG: Attempted to start new LLP transfer "
 287                                 "inside ongoing one\n");
 288                         return;
 289                 }
 290
 291                 dwc_initialize(dwc);
 292
 293                 dwc->residue = first->total_len;
 294                 dwc->tx_node_active = &first->tx_list;
 295
 296                 /* Submit first block */
 297                 dwc_do_single_block(dwc, first);
 298
 299                 return;
 300         }
 301
 302         dwc_initialize(dwc);
 303
 304         channel_writel(dwc, LLP, first->txd.phys);
 305         channel_writel(dwc, CTL_LO,
 306                         DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
 307         channel_writel(dwc, CTL_HI, 0);
 308         channel_set_bit(dw, CH_EN, dwc->mask);
 309 }
 310
 311 /*----------------------------------------------------------------------*/
 312
 313 static void
 314 dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc,
 315                 bool callback_required)
 316 {
 317         dma_async_tx_callback           callback = NULL;
 318         void                            *param = NULL;
 319         struct dma_async_tx_descriptor  *txd = &desc->txd;
 320         struct dw_desc                  *child;
 321         unsigned long                   flags;
 322
 323         dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
 324
 325         spin_lock_irqsave(&dwc->lock, flags);
 326         dma_cookie_complete(txd);
 327         if (callback_required) {
 328                 callback = txd->callback;
 329                 param = txd->callback_param;
 330         }
 331
 332         /* async_tx_ack */
 333         list_for_each_entry(child, &desc->tx_list, desc_node)
 334                 async_tx_ack(&child->txd);
 335         async_tx_ack(&desc->txd);
 336
 337         list_splice_init(&desc->tx_list, &dwc->free_list);
 338         list_move(&desc->desc_node, &dwc->free_list);
 339
 340         if (!is_slave_direction(dwc->direction)) {
 341                 struct device *parent = chan2parent(&dwc->chan);
 342                 if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
 343                         if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
 344                                 dma_unmap_single(parent, desc->lli.dar,
 345                                         desc->total_len, DMA_FROM_DEVICE);
 346                         else
 347                                 dma_unmap_page(parent, desc->lli.dar,
 348                                         desc->total_len, DMA_FROM_DEVICE);
 349                 }
 350                 if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
 351                         if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
 352                                 dma_unmap_single(parent, desc->lli.sar,
 353                                         desc->total_len, DMA_TO_DEVICE);
 354                         else
 355                                 dma_unmap_page(parent, desc->lli.sar,
 356                                         desc->total_len, DMA_TO_DEVICE);
 357                 }
 358         }
 359
 360         spin_unlock_irqrestore(&dwc->lock, flags);
 361
 362         if (callback)
 363                 callback(param);
 364 }
 365
 366 static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
 367 {
 368         struct dw_desc *desc, *_desc;
 369         LIST_HEAD(list);
 370         unsigned long flags;
 371
 372         spin_lock_irqsave(&dwc->lock, flags);
 373         if (dma_readl(dw, CH_EN) & dwc->mask) {
 374                 dev_err(chan2dev(&dwc->chan),
 375                         "BUG: XFER bit set, but channel not idle!\n");
 376
 377                 /* Try to continue after resetting the channel... */
 378                 dwc_chan_disable(dw, dwc);
 379         }
 380
 381         /*
 382          * Submit queued descriptors ASAP, i.e. before we go through
 383          * the completed ones.
 384          */
 385         list_splice_init(&dwc->active_list, &list);
 386         if (!list_empty(&dwc->queue)) {
 387                 list_move(dwc->queue.next, &dwc->active_list);
 388                 dwc_dostart(dwc, dwc_first_active(dwc));
 389         }
 390
 391         spin_unlock_irqrestore(&dwc->lock, flags);
 392
 393         list_for_each_entry_safe(desc, _desc, &list, desc_node)
 394                 dwc_descriptor_complete(dwc, desc, true);
 395 }
 396
 397 /* Returns how many bytes were already received from source */
 398 static inline u32 dwc_get_sent(struct dw_dma_chan *dwc)
 399 {
 400         u32 ctlhi = channel_readl(dwc, CTL_HI);
 401         u32 ctllo = channel_readl(dwc, CTL_LO);
 402
 403         return (ctlhi & DWC_CTLH_BLOCK_TS_MASK) * (1 << (ctllo >> 4 & 7));
 404 }
 405
 406 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
 407 {
 408         dma_addr_t llp;
 409         struct dw_desc *desc, *_desc;
 410         struct dw_desc *child;
 411         u32 status_xfer;
 412         unsigned long flags;
 413
 414         spin_lock_irqsave(&dwc->lock, flags);
 415         llp = channel_readl(dwc, LLP);
 416         status_xfer = dma_readl(dw, RAW.XFER);
 417
 418         if (status_xfer & dwc->mask) {
 419                 /* Everything we've submitted is done */
 420                 dma_writel(dw, CLEAR.XFER, dwc->mask);
 421
 422                 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
 423                         struct list_head *head, *active = dwc->tx_node_active;
 424
 425                         /*
 426                          * We are inside first active descriptor.
 427                          * Otherwise something is really wrong.
 428                          */
 429                         desc = dwc_first_active(dwc);
 430
 431                         head = &desc->tx_list;
 432                         if (active != head) {
 433                                 /* Update desc to reflect last sent one */
 434                                 if (active != head->next)
 435                                         desc = to_dw_desc(active->prev);
 436
 437                                 dwc->residue -= desc->len;
 438
 439                                 child = to_dw_desc(active);
 440
 441                                 /* Submit next block */
 442                                 dwc_do_single_block(dwc, child);
 443
 444                                 spin_unlock_irqrestore(&dwc->lock, flags);
 445                                 return;
 446                         }
 447
 448                         /* We are done here */
 449                         clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
 450                 }
 451
 452                 dwc->residue = 0;
 453
 454                 spin_unlock_irqrestore(&dwc->lock, flags);
 455
 456                 dwc_complete_all(dw, dwc);
 457                 return;
 458         }
 459
 460         if (list_empty(&dwc->active_list)) {
 461                 dwc->residue = 0;
 462                 spin_unlock_irqrestore(&dwc->lock, flags);
 463                 return;
 464         }
 465
 466         if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
 467                 dev_vdbg(chan2dev(&dwc->chan), "%s: soft LLP mode\n", __func__);
 468                 spin_unlock_irqrestore(&dwc->lock, flags);
 469                 return;
 470         }
 471
 472         dev_vdbg(chan2dev(&dwc->chan), "%s: llp=0x%llx\n", __func__,
 473                         (unsigned long long)llp);
 474
 475         list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
 476                 /* initial residue value */
 477                 dwc->residue = desc->total_len;
 478
 479                 /* check first descriptors addr */
 480                 if (desc->txd.phys == llp) {
 481                         spin_unlock_irqrestore(&dwc->lock, flags);
 482                         return;
 483                 }
 484
 485                 /* check first descriptors llp */
 486                 if (desc->lli.llp == llp) {
 487                         /* This one is currently in progress */
 488                         dwc->residue -= dwc_get_sent(dwc);
 489                         spin_unlock_irqrestore(&dwc->lock, flags);
 490                         return;
 491                 }
 492
 493                 dwc->residue -= desc->len;
 494                 list_for_each_entry(child, &desc->tx_list, desc_node) {
 495                         if (child->lli.llp == llp) {
 496                                 /* Currently in progress */
 497                                 dwc->residue -= dwc_get_sent(dwc);
 498                                 spin_unlock_irqrestore(&dwc->lock, flags);
 499                                 return;
 500                         }
 501                         dwc->residue -= child->len;
 502                 }
 503
 504                 /*
 505                  * No descriptors so far seem to be in progress, i.e.
 506                  * this one must be done.
 507                  */
 508                 spin_unlock_irqrestore(&dwc->lock, flags);
 509                 dwc_descriptor_complete(dwc, desc, true);
 510                 spin_lock_irqsave(&dwc->lock, flags);
 511         }
 512
 513         dev_err(chan2dev(&dwc->chan),
 514                 "BUG: All descriptors done, but channel not idle!\n");
 515
 516         /* Try to continue after resetting the channel... */
 517         dwc_chan_disable(dw, dwc);
 518
 519         if (!list_empty(&dwc->queue)) {
 520                 list_move(dwc->queue.next, &dwc->active_list);
 521                 dwc_dostart(dwc, dwc_first_active(dwc));
 522         }
 523         spin_unlock_irqrestore(&dwc->lock, flags);
 524 }
 525
 526 static inline void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli)
 527 {
 528         dev_crit(chan2dev(&dwc->chan), "  desc: s0x%x d0x%x l0x%x c0x%x:%x\n",
 529                  lli->sar, lli->dar, lli->llp, lli->ctlhi, lli->ctllo);
 530 }
 531
 532 static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
 533 {
 534         struct dw_desc *bad_desc;
 535         struct dw_desc *child;
 536         unsigned long flags;
 537
 538         dwc_scan_descriptors(dw, dwc);
 539
 540         spin_lock_irqsave(&dwc->lock, flags);
 541
 542         /*
 543          * The descriptor currently at the head of the active list is
 544          * borked. Since we don't have any way to report errors, we'll
 545          * just have to scream loudly and try to carry on.
 546          */
 547         bad_desc = dwc_first_active(dwc);
 548         list_del_init(&bad_desc->desc_node);
 549         list_move(dwc->queue.next, dwc->active_list.prev);
 550
 551         /* Clear the error flag and try to restart the controller */
 552         dma_writel(dw, CLEAR.ERROR, dwc->mask);
 553         if (!list_empty(&dwc->active_list))
 554                 dwc_dostart(dwc, dwc_first_active(dwc));
 555
 556         /*
 557          * WARN may seem harsh, but since this only happens
 558          * when someone submits a bad physical address in a
 559          * descriptor, we should consider ourselves lucky that the
 560          * controller flagged an error instead of scribbling over
 561          * random memory locations.
 562          */
 563         dev_WARN(chan2dev(&dwc->chan), "Bad descriptor submitted for DMA!\n"
 564                                        "  cookie: %d\n", bad_desc->txd.cookie);
 565         dwc_dump_lli(dwc, &bad_desc->lli);
 566         list_for_each_entry(child, &bad_desc->tx_list, desc_node)
 567                 dwc_dump_lli(dwc, &child->lli);
 568
 569         spin_unlock_irqrestore(&dwc->lock, flags);
 570
 571         /* Pretend the descriptor completed successfully */
 572         dwc_descriptor_complete(dwc, bad_desc, true);
 573 }
 574
 575 /* --------------------- Cyclic DMA API extensions -------------------- */
 576
 577 inline dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan)
 578 {
 579         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 580         return channel_readl(dwc, SAR);
 581 }
 582 EXPORT_SYMBOL(dw_dma_get_src_addr);
 583
 584 inline dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan)
 585 {
 586         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 587         return channel_readl(dwc, DAR);
 588 }
 589 EXPORT_SYMBOL(dw_dma_get_dst_addr);
 590
 591 /* called with dwc->lock held and all DMAC interrupts disabled */
 592 static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
 593                 u32 status_err, u32 status_xfer)
 594 {
 595         unsigned long flags;
 596
 597         if (dwc->mask) {
 598                 void (*callback)(void *param);
 599                 void *callback_param;
 600
 601                 dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp 0x%08x\n",
 602                                 channel_readl(dwc, LLP));
 603
 604                 callback = dwc->cdesc->period_callback;
 605                 callback_param = dwc->cdesc->period_callback_param;
 606
 607                 if (callback)
 608                         callback(callback_param);
 609         }
 610
 611         /*
 612          * Error and transfer complete are highly unlikely, and will most
 613          * likely be due to a configuration error by the user.
 614          */
 615         if (unlikely(status_err & dwc->mask) ||
 616                         unlikely(status_xfer & dwc->mask)) {
 617                 int i;
 618
 619                 dev_err(chan2dev(&dwc->chan), "cyclic DMA unexpected %s "
 620                                 "interrupt, stopping DMA transfer\n",
 621                                 status_xfer ? "xfer" : "error");
 622
 623                 spin_lock_irqsave(&dwc->lock, flags);
 624
 625                 dwc_dump_chan_regs(dwc);
 626
 627                 dwc_chan_disable(dw, dwc);
 628
 629                 /* make sure DMA does not restart by loading a new list */
 630                 channel_writel(dwc, LLP, 0);
 631                 channel_writel(dwc, CTL_LO, 0);
 632                 channel_writel(dwc, CTL_HI, 0);
 633
 634                 dma_writel(dw, CLEAR.ERROR, dwc->mask);
 635                 dma_writel(dw, CLEAR.XFER, dwc->mask);
 636
 637                 for (i = 0; i < dwc->cdesc->periods; i++)
 638                         dwc_dump_lli(dwc, &dwc->cdesc->desc[i]->lli);
 639
 640                 spin_unlock_irqrestore(&dwc->lock, flags);
 641         }
 642 }
 643
 644 /* ------------------------------------------------------------------------- */
 645
 646 static void dw_dma_tasklet(unsigned long data)
 647 {
 648         struct dw_dma *dw = (struct dw_dma *)data;
 649         struct dw_dma_chan *dwc;
 650         u32 status_xfer;
 651         u32 status_err;
 652         int i;
 653
 654         status_xfer = dma_readl(dw, RAW.XFER);
 655         status_err = dma_readl(dw, RAW.ERROR);
 656
 657         dev_vdbg(dw->dma.dev, "%s: status_err=%x\n", __func__, status_err);
 658
 659         for (i = 0; i < dw->dma.chancnt; i++) {
 660                 dwc = &dw->chan[i];
 661                 if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
 662                         dwc_handle_cyclic(dw, dwc, status_err, status_xfer);
 663                 else if (status_err & (1 << i))
 664                         dwc_handle_error(dw, dwc);
 665                 else if (status_xfer & (1 << i))
 666                         dwc_scan_descriptors(dw, dwc);
 667         }
 668
 669         /*
 670          * Re-enable interrupts.
 671          */
 672         channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
 673         channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask);
 674 }
 675
 676 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
 677 {
 678         struct dw_dma *dw = dev_id;
 679         u32 status;
 680
 681         dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__,
 682                         dma_readl(dw, STATUS_INT));
 683
 684         /*
 685          * Just disable the interrupts. We'll turn them back on in the
 686          * softirq handler.
 687          */
 688         channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
 689         channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
 690
 691         status = dma_readl(dw, STATUS_INT);
 692         if (status) {
 693                 dev_err(dw->dma.dev,
 694                         "BUG: Unexpected interrupts pending: 0x%x\n",
 695                         status);
 696
 697                 /* Try to recover */
 698                 channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1);
 699                 channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1);
 700                 channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1);
 701                 channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1);
 702         }
 703
 704         tasklet_schedule(&dw->tasklet);
 705
 706         return IRQ_HANDLED;
 707 }
 708
 709 /*----------------------------------------------------------------------*/
 710
 711 static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
 712 {
 713         struct dw_desc          *desc = txd_to_dw_desc(tx);
 714         struct dw_dma_chan      *dwc = to_dw_dma_chan(tx->chan);
 715         dma_cookie_t            cookie;
 716         unsigned long           flags;
 717
 718         spin_lock_irqsave(&dwc->lock, flags);
 719         cookie = dma_cookie_assign(tx);
 720
 721         /*
 722          * REVISIT: We should attempt to chain as many descriptors as
 723          * possible, perhaps even appending to those already submitted
 724          * for DMA. But this is hard to do in a race-free manner.
 725          */
 726         if (list_empty(&dwc->active_list)) {
 727                 dev_vdbg(chan2dev(tx->chan), "%s: started %u\n", __func__,
 728                                 desc->txd.cookie);
 729                 list_add_tail(&desc->desc_node, &dwc->active_list);
 730                 dwc_dostart(dwc, dwc_first_active(dwc));
 731         } else {
 732                 dev_vdbg(chan2dev(tx->chan), "%s: queued %u\n", __func__,
 733                                 desc->txd.cookie);
 734
 735                 list_add_tail(&desc->desc_node, &dwc->queue);
 736         }
 737
 738         spin_unlock_irqrestore(&dwc->lock, flags);
 739
 740         return cookie;
 741 }
 742
 743 static struct dma_async_tx_descriptor *
 744 dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 745                 size_t len, unsigned long flags)
 746 {
 747         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 748         struct dw_desc          *desc;
 749         struct dw_desc          *first;
 750         struct dw_desc          *prev;
 751         size_t                  xfer_count;
 752         size_t                  offset;
 753         unsigned int            src_width;
 754         unsigned int            dst_width;
 755         unsigned int            data_width;
 756         u32                     ctllo;
 757
 758         dev_vdbg(chan2dev(chan),
 759                         "%s: d0x%llx s0x%llx l0x%zx f0x%lx\n", __func__,
 760                         (unsigned long long)dest, (unsigned long long)src,
 761                         len, flags);
 762
 763         if (unlikely(!len)) {
 764                 dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__);
 765                 return NULL;
 766         }
 767
 768         dwc->direction = DMA_MEM_TO_MEM;
 769
 770         data_width = min_t(unsigned int, dwc_get_data_width(chan, SRC_MASTER),
 771                            dwc_get_data_width(chan, DST_MASTER));
 772
 773         src_width = dst_width = min_t(unsigned int, data_width,
 774                                       dwc_fast_fls(src | dest | len));
 775
 776         ctllo = DWC_DEFAULT_CTLLO(chan)
 777                         | DWC_CTLL_DST_WIDTH(dst_width)
 778                         | DWC_CTLL_SRC_WIDTH(src_width)
 779                         | DWC_CTLL_DST_INC
 780                         | DWC_CTLL_SRC_INC
 781                         | DWC_CTLL_FC_M2M;
 782         prev = first = NULL;
 783
 784         for (offset = 0; offset < len; offset += xfer_count << src_width) {
 785                 xfer_count = min_t(size_t, (len - offset) >> src_width,
 786                                            dwc->block_size);
 787
 788                 desc = dwc_desc_get(dwc);
 789                 if (!desc)
 790                         goto err_desc_get;
 791
 792                 desc->lli.sar = src + offset;
 793                 desc->lli.dar = dest + offset;
 794                 desc->lli.ctllo = ctllo;
 795                 desc->lli.ctlhi = xfer_count;
 796                 desc->len = xfer_count << src_width;
 797
 798                 if (!first) {
 799                         first = desc;
 800                 } else {
 801                         prev->lli.llp = desc->txd.phys;
 802                         list_add_tail(&desc->desc_node,
 803                                         &first->tx_list);
 804                 }
 805                 prev = desc;
 806         }
 807
 808         if (flags & DMA_PREP_INTERRUPT)
 809                 /* Trigger interrupt after last block */
 810                 prev->lli.ctllo |= DWC_CTLL_INT_EN;
 811
 812         prev->lli.llp = 0;
 813         first->txd.flags = flags;
 814         first->total_len = len;
 815
 816         return &first->txd;
 817
 818 err_desc_get:
 819         dwc_desc_put(dwc, first);
 820         return NULL;
 821 }
 822
 823 static struct dma_async_tx_descriptor *
 824 dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 825                 unsigned int sg_len, enum dma_transfer_direction direction,
 826                 unsigned long flags, void *context)
 827 {
 828         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 829         struct dma_slave_config *sconfig = &dwc->dma_sconfig;
 830         struct dw_desc          *prev;
 831         struct dw_desc          *first;
 832         u32                     ctllo;
 833         dma_addr_t              reg;
 834         unsigned int            reg_width;
 835         unsigned int            mem_width;
 836         unsigned int            data_width;
 837         unsigned int            i;
 838         struct scatterlist      *sg;
 839         size_t                  total_len = 0;
 840
 841         dev_vdbg(chan2dev(chan), "%s\n", __func__);
 842
 843         if (unlikely(!is_slave_direction(direction) || !sg_len))
 844                 return NULL;
 845
 846         dwc->direction = direction;
 847
 848         prev = first = NULL;
 849
 850         switch (direction) {
 851         case DMA_MEM_TO_DEV:
 852                 reg_width = __fls(sconfig->dst_addr_width);
 853                 reg = sconfig->dst_addr;
 854                 ctllo = (DWC_DEFAULT_CTLLO(chan)
 855                                 | DWC_CTLL_DST_WIDTH(reg_width)
 856                                 | DWC_CTLL_DST_FIX
 857                                 | DWC_CTLL_SRC_INC);
 858
 859                 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
 860                         DWC_CTLL_FC(DW_DMA_FC_D_M2P);
 861
 862                 data_width = dwc_get_data_width(chan, SRC_MASTER);
 863
 864                 for_each_sg(sgl, sg, sg_len, i) {
 865                         struct dw_desc  *desc;
 866                         u32             len, dlen, mem;
 867
 868                         mem = sg_dma_address(sg);
 869                         len = sg_dma_len(sg);
 870
 871                         mem_width = min_t(unsigned int,
 872                                           data_width, dwc_fast_fls(mem | len));
 873
 874 slave_sg_todev_fill_desc:
 875                         desc = dwc_desc_get(dwc);
 876                         if (!desc) {
 877                                 dev_err(chan2dev(chan),
 878                                         "not enough descriptors available\n");
 879                                 goto err_desc_get;
 880                         }
 881
 882                         desc->lli.sar = mem;
 883                         desc->lli.dar = reg;
 884                         desc->lli.ctllo = ctllo | DWC_CTLL_SRC_WIDTH(mem_width);
 885                         if ((len >> mem_width) > dwc->block_size) {
 886                                 dlen = dwc->block_size << mem_width;
 887                                 mem += dlen;
 888                                 len -= dlen;
 889                         } else {
 890                                 dlen = len;
 891                                 len = 0;
 892                         }
 893
 894                         desc->lli.ctlhi = dlen >> mem_width;
 895                         desc->len = dlen;
 896
 897                         if (!first) {
 898                                 first = desc;
 899                         } else {
 900                                 prev->lli.llp = desc->txd.phys;
 901                                 list_add_tail(&desc->desc_node,
 902                                                 &first->tx_list);
 903                         }
 904                         prev = desc;
 905                         total_len += dlen;
 906
 907                         if (len)
 908                                 goto slave_sg_todev_fill_desc;
 909                 }
 910                 break;
 911         case DMA_DEV_TO_MEM:
 912                 reg_width = __fls(sconfig->src_addr_width);
 913                 reg = sconfig->src_addr;
 914                 ctllo = (DWC_DEFAULT_CTLLO(chan)
 915                                 | DWC_CTLL_SRC_WIDTH(reg_width)
 916                                 | DWC_CTLL_DST_INC
 917                                 | DWC_CTLL_SRC_FIX);
 918
 919                 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
 920                         DWC_CTLL_FC(DW_DMA_FC_D_P2M);
 921
 922                 data_width = dwc_get_data_width(chan, DST_MASTER);
 923
 924                 for_each_sg(sgl, sg, sg_len, i) {
 925                         struct dw_desc  *desc;
 926                         u32             len, dlen, mem;
 927
 928                         mem = sg_dma_address(sg);
 929                         len = sg_dma_len(sg);
 930
 931                         mem_width = min_t(unsigned int,
 932                                           data_width, dwc_fast_fls(mem | len));
 933
 934 slave_sg_fromdev_fill_desc:
 935                         desc = dwc_desc_get(dwc);
 936                         if (!desc) {
 937                                 dev_err(chan2dev(chan),
 938                                                 "not enough descriptors available\n");
 939                                 goto err_desc_get;
 940                         }
 941
 942                         desc->lli.sar = reg;
 943                         desc->lli.dar = mem;
 944                         desc->lli.ctllo = ctllo | DWC_CTLL_DST_WIDTH(mem_width);
 945                         if ((len >> reg_width) > dwc->block_size) {
 946                                 dlen = dwc->block_size << reg_width;
 947                                 mem += dlen;
 948                                 len -= dlen;
 949                         } else {
 950                                 dlen = len;
 951                                 len = 0;
 952                         }
 953                         desc->lli.ctlhi = dlen >> reg_width;
 954                         desc->len = dlen;
 955
 956                         if (!first) {
 957                                 first = desc;
 958                         } else {
 959                                 prev->lli.llp = desc->txd.phys;
 960                                 list_add_tail(&desc->desc_node,
 961                                                 &first->tx_list);
 962                         }
 963                         prev = desc;
 964                         total_len += dlen;
 965
 966                         if (len)
 967                                 goto slave_sg_fromdev_fill_desc;
 968                 }
 969                 break;
 970         default:
 971                 return NULL;
 972         }
 973
 974         if (flags & DMA_PREP_INTERRUPT)
 975                 /* Trigger interrupt after last block */
 976                 prev->lli.ctllo |= DWC_CTLL_INT_EN;
 977
 978         prev->lli.llp = 0;
 979         first->total_len = total_len;
 980
 981         return &first->txd;
 982
 983 err_desc_get:
 984         dwc_desc_put(dwc, first);
 985         return NULL;
 986 }
 987
 988 /*
 989  * Fix sconfig's burst size according to dw_dmac. We need to convert them as:
 990  * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
 991  *
 992  * NOTE: burst size 2 is not supported by controller.
 993  *
 994  * This can be done by finding least significant bit set: n & (n - 1)
 995  */
 996 static inline void convert_burst(u32 *maxburst)
 997 {
 998         if (*maxburst > 1)
 999                 *maxburst = fls(*maxburst) - 2;
1000         else
1001                 *maxburst = 0;
1002 }
1003
1004 static inline void convert_slave_id(struct dw_dma_chan *dwc)
1005 {
1006         struct dw_dma *dw = to_dw_dma(dwc->chan.device);
1007
1008         dwc->dma_sconfig.slave_id -= dw->request_line_base;
1009 }
1010
1011 static int
1012 set_runtime_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
1013 {
1014         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1015
1016         /* Check if chan will be configured for slave transfers */
1017         if (!is_slave_direction(sconfig->direction))
1018                 return -EINVAL;
1019
1020         memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig));
1021         dwc->direction = sconfig->direction;
1022
1023         convert_burst(&dwc->dma_sconfig.src_maxburst);
1024         convert_burst(&dwc->dma_sconfig.dst_maxburst);
1025         convert_slave_id(dwc);
1026
1027         return 0;
1028 }
1029
1030 static inline void dwc_chan_pause(struct dw_dma_chan *dwc)
1031 {
1032         u32 cfglo = channel_readl(dwc, CFG_LO);
1033
1034         channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
1035         while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY))
1036                 cpu_relax();
1037
1038         dwc->paused = true;
1039 }
1040
1041 static inline void dwc_chan_resume(struct dw_dma_chan *dwc)
1042 {
1043         u32 cfglo = channel_readl(dwc, CFG_LO);
1044
1045         channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
1046
1047         dwc->paused = false;
1048 }
1049
1050 static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
1051                        unsigned long arg)
1052 {
1053         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1054         struct dw_dma           *dw = to_dw_dma(chan->device);
1055         struct dw_desc          *desc, *_desc;
1056         unsigned long           flags;
1057         LIST_HEAD(list);
1058
1059         if (cmd == DMA_PAUSE) {
1060                 spin_lock_irqsave(&dwc->lock, flags);
1061
1062                 dwc_chan_pause(dwc);
1063
1064                 spin_unlock_irqrestore(&dwc->lock, flags);
1065         } else if (cmd == DMA_RESUME) {
1066                 if (!dwc->paused)
1067                         return 0;
1068
1069                 spin_lock_irqsave(&dwc->lock, flags);
1070
1071                 dwc_chan_resume(dwc);
1072
1073                 spin_unlock_irqrestore(&dwc->lock, flags);
1074         } else if (cmd == DMA_TERMINATE_ALL) {
1075                 spin_lock_irqsave(&dwc->lock, flags);
1076
1077                 clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
1078
1079                 dwc_chan_disable(dw, dwc);
1080
1081                 dwc_chan_resume(dwc);
1082
1083                 /* active_list entries will end up before queued entries */
1084                 list_splice_init(&dwc->queue, &list);
1085                 list_splice_init(&dwc->active_list, &list);
1086
1087                 spin_unlock_irqrestore(&dwc->lock, flags);
1088
1089                 /* Flush all pending and queued descriptors */
1090                 list_for_each_entry_safe(desc, _desc, &list, desc_node)
1091                         dwc_descriptor_complete(dwc, desc, false);
1092         } else if (cmd == DMA_SLAVE_CONFIG) {
1093                 return set_runtime_config(chan, (struct dma_slave_config *)arg);
1094         } else {
1095                 return -ENXIO;
1096         }
1097
1098         return 0;
1099 }
1100
1101 static inline u32 dwc_get_residue(struct dw_dma_chan *dwc)
1102 {
1103         unsigned long flags;
1104         u32 residue;
1105
1106         spin_lock_irqsave(&dwc->lock, flags);
1107
1108         residue = dwc->residue;
1109         if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags) && residue)
1110                 residue -= dwc_get_sent(dwc);
1111
1112         spin_unlock_irqrestore(&dwc->lock, flags);
1113         return residue;
1114 }
1115
1116 static enum dma_status
1117 dwc_tx_status(struct dma_chan *chan,
1118               dma_cookie_t cookie,
1119               struct dma_tx_state *txstate)
1120 {
1121         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1122         enum dma_status         ret;
1123
1124         ret = dma_cookie_status(chan, cookie, txstate);
1125         if (ret != DMA_SUCCESS) {
1126                 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
1127
1128                 ret = dma_cookie_status(chan, cookie, txstate);
1129         }
1130
1131         if (ret != DMA_SUCCESS)
1132                 dma_set_residue(txstate, dwc_get_residue(dwc));
1133
1134         if (dwc->paused)
1135                 return DMA_PAUSED;
1136
1137         return ret;
1138 }
1139
1140 static void dwc_issue_pending(struct dma_chan *chan)
1141 {
1142         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1143
1144         if (!list_empty(&dwc->queue))
1145                 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
1146 }
1147
1148 static int dwc_alloc_chan_resources(struct dma_chan *chan)
1149 {
1150         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1151         struct dw_dma           *dw = to_dw_dma(chan->device);
1152         struct dw_desc          *desc;
1153         int                     i;
1154         unsigned long           flags;
1155
1156         dev_vdbg(chan2dev(chan), "%s\n", __func__);
1157
1158         /* ASSERT:  channel is idle */
1159         if (dma_readl(dw, CH_EN) & dwc->mask) {
1160                 dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
1161                 return -EIO;
1162         }
1163
1164         dma_cookie_init(chan);
1165
1166         /*
1167          * NOTE: some controllers may have additional features that we
1168          * need to initialize here, like "scatter-gather" (which
1169          * doesn't mean what you think it means), and status writeback.
1170          */
1171
1172         spin_lock_irqsave(&dwc->lock, flags);
1173         i = dwc->descs_allocated;
1174         while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) {
1175                 dma_addr_t phys;
1176
1177                 spin_unlock_irqrestore(&dwc->lock, flags);
1178
1179                 desc = dma_pool_alloc(dw->desc_pool, GFP_ATOMIC, &phys);
1180                 if (!desc)
1181                         goto err_desc_alloc;
1182
1183                 memset(desc, 0, sizeof(struct dw_desc));
1184
1185                 INIT_LIST_HEAD(&desc->tx_list);
1186                 dma_async_tx_descriptor_init(&desc->txd, chan);
1187                 desc->txd.tx_submit = dwc_tx_submit;
1188                 desc->txd.flags = DMA_CTRL_ACK;
1189                 desc->txd.phys = phys;
1190
1191                 dwc_desc_put(dwc, desc);
1192
1193                 spin_lock_irqsave(&dwc->lock, flags);
1194                 i = ++dwc->descs_allocated;
1195         }
1196
1197         spin_unlock_irqrestore(&dwc->lock, flags);
1198
1199         dev_dbg(chan2dev(chan), "%s: allocated %d descriptors\n", __func__, i);
1200
1201         return i;
1202
1203 err_desc_alloc:
1204         dev_info(chan2dev(chan), "only allocated %d descriptors\n", i);
1205
1206         return i;
1207 }
1208
1209 static void dwc_free_chan_resources(struct dma_chan *chan)
1210 {
1211         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1212         struct dw_dma           *dw = to_dw_dma(chan->device);
1213         struct dw_desc          *desc, *_desc;
1214         unsigned long           flags;
1215         LIST_HEAD(list);
1216
1217         dev_dbg(chan2dev(chan), "%s: descs allocated=%u\n", __func__,
1218                         dwc->descs_allocated);
1219
1220         /* ASSERT:  channel is idle */
1221         BUG_ON(!list_empty(&dwc->active_list));
1222         BUG_ON(!list_empty(&dwc->queue));
1223         BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
1224
1225         spin_lock_irqsave(&dwc->lock, flags);
1226         list_splice_init(&dwc->free_list, &list);
1227         dwc->descs_allocated = 0;
1228         dwc->initialized = false;
1229
1230         /* Disable interrupts */
1231         channel_clear_bit(dw, MASK.XFER, dwc->mask);
1232         channel_clear_bit(dw, MASK.ERROR, dwc->mask);
1233
1234         spin_unlock_irqrestore(&dwc->lock, flags);
1235
1236         list_for_each_entry_safe(desc, _desc, &list, desc_node) {
1237                 dev_vdbg(chan2dev(chan), "  freeing descriptor %p\n", desc);
1238                 dma_pool_free(dw->desc_pool, desc, desc->txd.phys);
1239         }
1240
1241         dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
1242 }
1243
1244 struct dw_dma_filter_args {
1245         struct dw_dma *dw;
1246         unsigned int req;
1247         unsigned int src;
1248         unsigned int dst;
1249 };
1250
1251 static bool dw_dma_generic_filter(struct dma_chan *chan, void *param)
1252 {
1253         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1254         struct dw_dma *dw = to_dw_dma(chan->device);
1255         struct dw_dma_filter_args *fargs = param;
1256         struct dw_dma_slave *dws = &dwc->slave;
1257
1258         /* ensure the device matches our channel */
1259         if (chan->device != &fargs->dw->dma)
1260                 return false;
1261
1262         dws->dma_dev    = dw->dma.dev;
1263         dws->cfg_hi     = ~0;
1264         dws->cfg_lo     = ~0;
1265         dws->src_master = fargs->src;
1266         dws->dst_master = fargs->dst;
1267
1268         dwc->request_line = fargs->req;
1269
1270         chan->private = dws;
1271
1272         return true;
1273 }
1274
1275 static struct dma_chan *dw_dma_xlate(struct of_phandle_args *dma_spec,
1276                                          struct of_dma *ofdma)
1277 {
1278         struct dw_dma *dw = ofdma->of_dma_data;
1279         struct dw_dma_filter_args fargs = {
1280                 .dw = dw,
1281         };
1282         dma_cap_mask_t cap;
1283
1284         if (dma_spec->args_count != 3)
1285                 return NULL;
1286
1287         fargs.req = dma_spec->args[0];
1288         fargs.src = dma_spec->args[1];
1289         fargs.dst = dma_spec->args[2];
1290
1291         if (WARN_ON(fargs.req >= DW_DMA_MAX_NR_REQUESTS ||
1292                     fargs.src >= dw->nr_masters ||
1293                     fargs.dst >= dw->nr_masters))
1294                 return NULL;
1295
1296         dma_cap_zero(cap);
1297         dma_cap_set(DMA_SLAVE, cap);
1298
1299         /* TODO: there should be a simpler way to do this */
1300         return dma_request_channel(cap, dw_dma_generic_filter, &fargs);
1301 }
1302
1303 /* --------------------- Cyclic DMA API extensions -------------------- */
1304
1305 /**
1306  * dw_dma_cyclic_start - start the cyclic DMA transfer
1307  * @chan: the DMA channel to start
1308  *
1309  * Must be called with soft interrupts disabled. Returns zero on success or
1310  * -errno on failure.
1311  */
1312 int dw_dma_cyclic_start(struct dma_chan *chan)
1313 {
1314         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1315         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
1316         unsigned long           flags;
1317
1318         if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
1319                 dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n");
1320                 return -ENODEV;
1321         }
1322
1323         spin_lock_irqsave(&dwc->lock, flags);
1324
1325         /* assert channel is idle */
1326         if (dma_readl(dw, CH_EN) & dwc->mask) {
1327                 dev_err(chan2dev(&dwc->chan),
1328                         "BUG: Attempted to start non-idle channel\n");
1329                 dwc_dump_chan_regs(dwc);
1330                 spin_unlock_irqrestore(&dwc->lock, flags);
1331                 return -EBUSY;
1332         }
1333
1334         dma_writel(dw, CLEAR.ERROR, dwc->mask);
1335         dma_writel(dw, CLEAR.XFER, dwc->mask);
1336
1337         /* setup DMAC channel registers */
1338         channel_writel(dwc, LLP, dwc->cdesc->desc[0]->txd.phys);
1339         channel_writel(dwc, CTL_LO, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
1340         channel_writel(dwc, CTL_HI, 0);
1341
1342         channel_set_bit(dw, CH_EN, dwc->mask);
1343
1344         spin_unlock_irqrestore(&dwc->lock, flags);
1345
1346         return 0;
1347 }
1348 EXPORT_SYMBOL(dw_dma_cyclic_start);
1349
1350 /**
1351  * dw_dma_cyclic_stop - stop the cyclic DMA transfer
1352  * @chan: the DMA channel to stop
1353  *
1354  * Must be called with soft interrupts disabled.
1355  */
1356 void dw_dma_cyclic_stop(struct dma_chan *chan)
1357 {
1358         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1359         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
1360         unsigned long           flags;
1361
1362         spin_lock_irqsave(&dwc->lock, flags);
1363
1364         dwc_chan_disable(dw, dwc);
1365
1366         spin_unlock_irqrestore(&dwc->lock, flags);
1367 }
1368 EXPORT_SYMBOL(dw_dma_cyclic_stop);
1369
1370 /**
1371  * dw_dma_cyclic_prep - prepare the cyclic DMA transfer
1372  * @chan: the DMA channel to prepare
1373  * @buf_addr: physical DMA address where the buffer starts
1374  * @buf_len: total number of bytes for the entire buffer
1375  * @period_len: number of bytes for each period
1376  * @direction: transfer direction, to or from device
1377  *
1378  * Must be called before trying to start the transfer. Returns a valid struct
1379  * dw_cyclic_desc if successful or an ERR_PTR(-errno) if not successful.
1380  */
1381 struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
1382                 dma_addr_t buf_addr, size_t buf_len, size_t period_len,
1383                 enum dma_transfer_direction direction)
1384 {
1385         struct dw_dma_chan              *dwc = to_dw_dma_chan(chan);
1386         struct dma_slave_config         *sconfig = &dwc->dma_sconfig;
1387         struct dw_cyclic_desc           *cdesc;
1388         struct dw_cyclic_desc           *retval = NULL;
1389         struct dw_desc                  *desc;
1390         struct dw_desc                  *last = NULL;
1391         unsigned long                   was_cyclic;
1392         unsigned int                    reg_width;
1393         unsigned int                    periods;
1394         unsigned int                    i;
1395         unsigned long                   flags;
1396
1397         spin_lock_irqsave(&dwc->lock, flags);
1398         if (dwc->nollp) {
1399                 spin_unlock_irqrestore(&dwc->lock, flags);
1400                 dev_dbg(chan2dev(&dwc->chan),
1401                                 "channel doesn't support LLP transfers\n");
1402                 return ERR_PTR(-EINVAL);
1403         }
1404
1405         if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) {
1406                 spin_unlock_irqrestore(&dwc->lock, flags);
1407                 dev_dbg(chan2dev(&dwc->chan),
1408                                 "queue and/or active list are not empty\n");
1409                 return ERR_PTR(-EBUSY);
1410         }
1411
1412         was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1413         spin_unlock_irqrestore(&dwc->lock, flags);
1414         if (was_cyclic) {
1415                 dev_dbg(chan2dev(&dwc->chan),
1416                                 "channel already prepared for cyclic DMA\n");
1417                 return ERR_PTR(-EBUSY);
1418         }
1419
1420         retval = ERR_PTR(-EINVAL);
1421
1422         if (unlikely(!is_slave_direction(direction)))
1423                 goto out_err;
1424
1425         dwc->direction = direction;
1426
1427         if (direction == DMA_MEM_TO_DEV)
1428                 reg_width = __ffs(sconfig->dst_addr_width);
1429         else
1430                 reg_width = __ffs(sconfig->src_addr_width);
1431
1432         periods = buf_len / period_len;
1433
1434         /* Check for too big/unaligned periods and unaligned DMA buffer. */
1435         if (period_len > (dwc->block_size << reg_width))
1436                 goto out_err;
1437         if (unlikely(period_len & ((1 << reg_width) - 1)))
1438                 goto out_err;
1439         if (unlikely(buf_addr & ((1 << reg_width) - 1)))
1440                 goto out_err;
1441
1442         retval = ERR_PTR(-ENOMEM);
1443
1444         if (periods > NR_DESCS_PER_CHANNEL)
1445                 goto out_err;
1446
1447         cdesc = kzalloc(sizeof(struct dw_cyclic_desc), GFP_KERNEL);
1448         if (!cdesc)
1449                 goto out_err;
1450
1451         cdesc->desc = kzalloc(sizeof(struct dw_desc *) * periods, GFP_KERNEL);
1452         if (!cdesc->desc)
1453                 goto out_err_alloc;
1454
1455         for (i = 0; i < periods; i++) {
1456                 desc = dwc_desc_get(dwc);
1457                 if (!desc)
1458                         goto out_err_desc_get;
1459
1460                 switch (direction) {
1461                 case DMA_MEM_TO_DEV:
1462                         desc->lli.dar = sconfig->dst_addr;
1463                         desc->lli.sar = buf_addr + (period_len * i);
1464                         desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan)
1465                                         | DWC_CTLL_DST_WIDTH(reg_width)
1466                                         | DWC_CTLL_SRC_WIDTH(reg_width)
1467                                         | DWC_CTLL_DST_FIX
1468                                         | DWC_CTLL_SRC_INC
1469                                         | DWC_CTLL_INT_EN);
1470
1471                         desc->lli.ctllo |= sconfig->device_fc ?
1472                                 DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
1473                                 DWC_CTLL_FC(DW_DMA_FC_D_M2P);
1474
1475                         break;
1476                 case DMA_DEV_TO_MEM:
1477                         desc->lli.dar = buf_addr + (period_len * i);
1478                         desc->lli.sar = sconfig->src_addr;
1479                         desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan)
1480                                         | DWC_CTLL_SRC_WIDTH(reg_width)
1481                                         | DWC_CTLL_DST_WIDTH(reg_width)
1482                                         | DWC_CTLL_DST_INC
1483                                         | DWC_CTLL_SRC_FIX
1484                                         | DWC_CTLL_INT_EN);
1485
1486                         desc->lli.ctllo |= sconfig->device_fc ?
1487                                 DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
1488                                 DWC_CTLL_FC(DW_DMA_FC_D_P2M);
1489
1490                         break;
1491                 default:
1492                         break;
1493                 }
1494
1495                 desc->lli.ctlhi = (period_len >> reg_width);
1496                 cdesc->desc[i] = desc;
1497
1498                 if (last)
1499                         last->lli.llp = desc->txd.phys;
1500
1501                 last = desc;
1502         }
1503
1504         /* lets make a cyclic list */
1505         last->lli.llp = cdesc->desc[0]->txd.phys;
1506
1507         dev_dbg(chan2dev(&dwc->chan), "cyclic prepared buf 0x%llx len %zu "
1508                         "period %zu periods %d\n", (unsigned long long)buf_addr,
1509                         buf_len, period_len, periods);
1510
1511         cdesc->periods = periods;
1512         dwc->cdesc = cdesc;
1513
1514         return cdesc;
1515
1516 out_err_desc_get:
1517         while (i--)
1518                 dwc_desc_put(dwc, cdesc->desc[i]);
1519 out_err_alloc:
1520         kfree(cdesc);
1521 out_err:
1522         clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1523         return (struct dw_cyclic_desc *)retval;
1524 }
1525 EXPORT_SYMBOL(dw_dma_cyclic_prep);
1526
1527 /**
1528  * dw_dma_cyclic_free - free a prepared cyclic DMA transfer
1529  * @chan: the DMA channel to free
1530  */
1531 void dw_dma_cyclic_free(struct dma_chan *chan)
1532 {
1533         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1534         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
1535         struct dw_cyclic_desc   *cdesc = dwc->cdesc;
1536         int                     i;
1537         unsigned long           flags;
1538
1539         dev_dbg(chan2dev(&dwc->chan), "%s\n", __func__);
1540
1541         if (!cdesc)
1542                 return;
1543
1544         spin_lock_irqsave(&dwc->lock, flags);
1545
1546         dwc_chan_disable(dw, dwc);
1547
1548         dma_writel(dw, CLEAR.ERROR, dwc->mask);
1549         dma_writel(dw, CLEAR.XFER, dwc->mask);
1550
1551         spin_unlock_irqrestore(&dwc->lock, flags);
1552
1553         for (i = 0; i < cdesc->periods; i++)
1554                 dwc_desc_put(dwc, cdesc->desc[i]);
1555
1556         kfree(cdesc->desc);
1557         kfree(cdesc);
1558
1559         clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1560 }
1561 EXPORT_SYMBOL(dw_dma_cyclic_free);
1562
1563 /*----------------------------------------------------------------------*/
1564
1565 static void dw_dma_off(struct dw_dma *dw)
1566 {
1567         int i;
1568
1569         dma_writel(dw, CFG, 0);
1570
1571         channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1572         channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1573         channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1574         channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1575
1576         while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
1577                 cpu_relax();
1578
1579         for (i = 0; i < dw->dma.chancnt; i++)
1580                 dw->chan[i].initialized = false;
1581 }
1582
1583 #ifdef CONFIG_OF
1584 static struct dw_dma_platform_data *
1585 dw_dma_parse_dt(struct platform_device *pdev)
1586 {
1587         struct device_node *np = pdev->dev.of_node;
1588         struct dw_dma_platform_data *pdata;
1589         u32 tmp, arr[4];
1590
1591         if (!np) {
1592                 dev_err(&pdev->dev, "Missing DT data\n");
1593                 return NULL;
1594         }
1595
1596         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
1597         if (!pdata)
1598                 return NULL;
1599
1600         if (of_property_read_u32(np, "dma-channels", &pdata->nr_channels))
1601                 return NULL;
1602
1603         if (of_property_read_bool(np, "is_private"))
1604                 pdata->is_private = true;
1605
1606         if (!of_property_read_u32(np, "chan_allocation_order", &tmp))
1607                 pdata->chan_allocation_order = (unsigned char)tmp;
1608
1609         if (!of_property_read_u32(np, "chan_priority", &tmp))
1610                 pdata->chan_priority = tmp;
1611
1612         if (!of_property_read_u32(np, "block_size", &tmp))
1613                 pdata->block_size = tmp;
1614
1615         if (!of_property_read_u32(np, "dma-masters", &tmp)) {
1616                 if (tmp > 4)
1617                         return NULL;
1618
1619                 pdata->nr_masters = tmp;
1620         }
1621
1622         if (!of_property_read_u32_array(np, "data_width", arr,
1623                                 pdata->nr_masters))
1624                 for (tmp = 0; tmp < pdata->nr_masters; tmp++)
1625                         pdata->data_width[tmp] = arr[tmp];
1626
1627         return pdata;
1628 }
1629 #else
1630 static inline struct dw_dma_platform_data *
1631 dw_dma_parse_dt(struct platform_device *pdev)
1632 {
1633         return NULL;
1634 }
1635 #endif
1636
1637 static int dw_probe(struct platform_device *pdev)
1638 {
1639         const struct platform_device_id *match;
1640         struct dw_dma_platform_data *pdata;
1641         struct resource         *io;
1642         struct dw_dma           *dw;
1643         size_t                  size;
1644         void __iomem            *regs;
1645         bool                    autocfg;
1646         unsigned int            dw_params;
1647         unsigned int            nr_channels;
1648         unsigned int            max_blk_size = 0;
1649         int                     irq;
1650         int                     err;
1651         int                     i;
1652
1653         io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1654         if (!io)
1655                 return -EINVAL;
1656
1657         irq = platform_get_irq(pdev, 0);
1658         if (irq < 0)
1659                 return irq;
1660
1661         regs = devm_ioremap_resource(&pdev->dev, io);
1662         if (IS_ERR(regs))
1663                 return PTR_ERR(regs);
1664
1665         /* Apply default dma_mask if needed */
1666         if (!pdev->dev.dma_mask) {
1667                 pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
1668                 pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
1669         }
1670
1671         dw_params = dma_read_byaddr(regs, DW_PARAMS);
1672         autocfg = dw_params >> DW_PARAMS_EN & 0x1;
1673
1674         dev_dbg(&pdev->dev, "DW_PARAMS: 0x%08x\n", dw_params);
1675
1676         pdata = dev_get_platdata(&pdev->dev);
1677         if (!pdata)
1678                 pdata = dw_dma_parse_dt(pdev);
1679
1680         if (!pdata && autocfg) {
1681                 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
1682                 if (!pdata)
1683                         return -ENOMEM;
1684
1685                 /* Fill platform data with the default values */
1686                 pdata->is_private = true;
1687                 pdata->chan_allocation_order = CHAN_ALLOCATION_ASCENDING;
1688                 pdata->chan_priority = CHAN_PRIORITY_ASCENDING;
1689         } else if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS)
1690                 return -EINVAL;
1691
1692         if (autocfg)
1693                 nr_channels = (dw_params >> DW_PARAMS_NR_CHAN & 0x7) + 1;
1694         else
1695                 nr_channels = pdata->nr_channels;
1696
1697         size = sizeof(struct dw_dma) + nr_channels * sizeof(struct dw_dma_chan);
1698         dw = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
1699         if (!dw)
1700                 return -ENOMEM;
1701
1702         dw->clk = devm_clk_get(&pdev->dev, "hclk");
1703         if (IS_ERR(dw->clk))
1704                 return PTR_ERR(dw->clk);
1705         clk_prepare_enable(dw->clk);
1706
1707         dw->regs = regs;
1708
1709         /* get hardware configuration parameters */
1710         if (autocfg) {
1711                 max_blk_size = dma_readl(dw, MAX_BLK_SIZE);
1712
1713                 dw->nr_masters = (dw_params >> DW_PARAMS_NR_MASTER & 3) + 1;
1714                 for (i = 0; i < dw->nr_masters; i++) {
1715                         dw->data_width[i] =
1716                                 (dw_params >> DW_PARAMS_DATA_WIDTH(i) & 3) + 2;
1717                 }
1718         } else {
1719                 dw->nr_masters = pdata->nr_masters;
1720                 memcpy(dw->data_width, pdata->data_width, 4);
1721         }
1722
1723         /* Get the base request line if set */
1724         match = platform_get_device_id(pdev);
1725         if (match)
1726                 dw->request_line_base = (unsigned int)match->driver_data;
1727
1728         /* Calculate all channel mask before DMA setup */
1729         dw->all_chan_mask = (1 << nr_channels) - 1;
1730
1731         /* force dma off, just in case */
1732         dw_dma_off(dw);
1733
1734         /* disable BLOCK interrupts as well */
1735         channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1736
1737         err = devm_request_irq(&pdev->dev, irq, dw_dma_interrupt, 0,
1738                                "dw_dmac", dw);
1739         if (err)
1740                 return err;
1741
1742         platform_set_drvdata(pdev, dw);
1743
1744         /* create a pool of consistent memory blocks for hardware descriptors */
1745         dw->desc_pool = dmam_pool_create("dw_dmac_desc_pool", &pdev->dev,
1746                                          sizeof(struct dw_desc), 4, 0);
1747         if (!dw->desc_pool) {
1748                 dev_err(&pdev->dev, "No memory for descriptors dma pool\n");
1749                 return -ENOMEM;
1750         }
1751
1752         tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
1753
1754         INIT_LIST_HEAD(&dw->dma.channels);
1755         for (i = 0; i < nr_channels; i++) {
1756                 struct dw_dma_chan      *dwc = &dw->chan[i];
1757                 int                     r = nr_channels - i - 1;
1758
1759                 dwc->chan.device = &dw->dma;
1760                 dma_cookie_init(&dwc->chan);
1761                 if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING)
1762                         list_add_tail(&dwc->chan.device_node,
1763                                         &dw->dma.channels);
1764                 else
1765                         list_add(&dwc->chan.device_node, &dw->dma.channels);
1766
1767                 /* 7 is highest priority & 0 is lowest. */
1768                 if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING)
1769                         dwc->priority = r;
1770                 else
1771                         dwc->priority = i;
1772
1773                 dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
1774                 spin_lock_init(&dwc->lock);
1775                 dwc->mask = 1 << i;
1776
1777                 INIT_LIST_HEAD(&dwc->active_list);
1778                 INIT_LIST_HEAD(&dwc->queue);
1779                 INIT_LIST_HEAD(&dwc->free_list);
1780
1781                 channel_clear_bit(dw, CH_EN, dwc->mask);
1782
1783                 dwc->direction = DMA_TRANS_NONE;
1784
1785                 /* hardware configuration */
1786                 if (autocfg) {
1787                         unsigned int dwc_params;
1788
1789                         dwc_params = dma_read_byaddr(regs + r * sizeof(u32),
1790                                                      DWC_PARAMS);
1791
1792                         dev_dbg(&pdev->dev, "DWC_PARAMS[%d]: 0x%08x\n", i,
1793                                             dwc_params);
1794
1795                         /* Decode maximum block size for given channel. The
1796                          * stored 4 bit value represents blocks from 0x00 for 3
1797                          * up to 0x0a for 4095. */
1798                         dwc->block_size =
1799                                 (4 << ((max_blk_size >> 4 * i) & 0xf)) - 1;
1800                         dwc->nollp =
1801                                 (dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0;
1802                 } else {
1803                         dwc->block_size = pdata->block_size;
1804
1805                         /* Check if channel supports multi block transfer */
1806                         channel_writel(dwc, LLP, 0xfffffffc);
1807                         dwc->nollp =
1808                                 (channel_readl(dwc, LLP) & 0xfffffffc) == 0;
1809                         channel_writel(dwc, LLP, 0);
1810                 }
1811         }
1812
1813         /* Clear all interrupts on all channels. */
1814         dma_writel(dw, CLEAR.XFER, dw->all_chan_mask);
1815         dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask);
1816         dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask);
1817         dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask);
1818         dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask);
1819
1820         dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
1821         dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
1822         if (pdata->is_private)
1823                 dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask);
1824         dw->dma.dev = &pdev->dev;
1825         dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
1826         dw->dma.device_free_chan_resources = dwc_free_chan_resources;
1827
1828         dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
1829
1830         dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
1831         dw->dma.device_control = dwc_control;
1832
1833         dw->dma.device_tx_status = dwc_tx_status;
1834         dw->dma.device_issue_pending = dwc_issue_pending;
1835
1836         dma_writel(dw, CFG, DW_CFG_DMA_EN);
1837
1838         dev_info(&pdev->dev, "DesignWare DMA Controller, %d channels\n",
1839                  nr_channels);
1840
1841         dma_async_device_register(&dw->dma);
1842
1843         if (pdev->dev.of_node) {
1844                 err = of_dma_controller_register(pdev->dev.of_node,
1845                                                  dw_dma_xlate, dw);
1846                 if (err && err != -ENODEV)
1847                         dev_err(&pdev->dev,
1848                                 "could not register of_dma_controller\n");
1849         }
1850
1851         return 0;
1852 }
1853
1854 static int dw_remove(struct platform_device *pdev)
1855 {
1856         struct dw_dma           *dw = platform_get_drvdata(pdev);
1857         struct dw_dma_chan      *dwc, *_dwc;
1858
1859         if (pdev->dev.of_node)
1860                 of_dma_controller_free(pdev->dev.of_node);
1861         dw_dma_off(dw);
1862         dma_async_device_unregister(&dw->dma);
1863
1864         tasklet_kill(&dw->tasklet);
1865
1866         list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,
1867                         chan.device_node) {
1868                 list_del(&dwc->chan.device_node);
1869                 channel_clear_bit(dw, CH_EN, dwc->mask);
1870         }
1871
1872         return 0;
1873 }
1874
1875 static void dw_shutdown(struct platform_device *pdev)
1876 {
1877         struct dw_dma   *dw = platform_get_drvdata(pdev);
1878
1879         dw_dma_off(dw);
1880         clk_disable_unprepare(dw->clk);
1881 }
1882
1883 static int dw_suspend_noirq(struct device *dev)
1884 {
1885         struct platform_device *pdev = to_platform_device(dev);
1886         struct dw_dma   *dw = platform_get_drvdata(pdev);
1887
1888         dw_dma_off(dw);
1889         clk_disable_unprepare(dw->clk);
1890
1891         return 0;
1892 }
1893
1894 static int dw_resume_noirq(struct device *dev)
1895 {
1896         struct platform_device *pdev = to_platform_device(dev);
1897         struct dw_dma   *dw = platform_get_drvdata(pdev);
1898
1899         clk_prepare_enable(dw->clk);
1900         dma_writel(dw, CFG, DW_CFG_DMA_EN);
1901
1902         return 0;
1903 }
1904
1905 static const struct dev_pm_ops dw_dev_pm_ops = {
1906         .suspend_noirq = dw_suspend_noirq,
1907         .resume_noirq = dw_resume_noirq,
1908         .freeze_noirq = dw_suspend_noirq,
1909         .thaw_noirq = dw_resume_noirq,
1910         .restore_noirq = dw_resume_noirq,
1911         .poweroff_noirq = dw_suspend_noirq,
1912 };
1913
1914 #ifdef CONFIG_OF
1915 static const struct of_device_id dw_dma_id_table[] = {
1916         { .compatible = "snps,dma-spear1340" },
1917         {}
1918 };
1919 MODULE_DEVICE_TABLE(of, dw_dma_id_table);
1920 #endif
1921
1922 static const struct platform_device_id dw_dma_ids[] = {
1923         /* Name,        Request Line Base */
1924         { "INTL9C60",   (kernel_ulong_t)16 },
1925         { }
1926 };
1927
1928 static struct platform_driver dw_driver = {
1929         .probe          = dw_probe,
1930         .remove         = dw_remove,
1931         .shutdown       = dw_shutdown,
1932         .driver = {
1933                 .name   = "dw_dmac",
1934                 .pm     = &dw_dev_pm_ops,
1935                 .of_match_table = of_match_ptr(dw_dma_id_table),
1936         },
1937         .id_table       = dw_dma_ids,
1938 };
1939
1940 static int __init dw_init(void)
1941 {
1942         return platform_driver_register(&dw_driver);
1943 }
1944 subsys_initcall(dw_init);
1945
1946 static void __exit dw_exit(void)
1947 {
1948         platform_driver_unregister(&dw_driver);
1949 }
1950 module_exit(dw_exit);
1951
1952 MODULE_LICENSE("GPL v2");
1953 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller driver");
1954 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
1955 MODULE_AUTHOR("Viresh Kumar <viresh.linux@gmail.com>");