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 #include <linux/acpi.h>
  29 #include <linux/acpi_dma.h>
  30
  31 #include "dw_dmac_regs.h"
  32 #include "dmaengine.h"
  33
  34 /*
  35  * This supports the Synopsys "DesignWare AHB Central DMA Controller",
  36  * (DW_ahb_dmac) which is used with various AMBA 2.0 systems (not all
  37  * of which use ARM any more).  See the "Databook" from Synopsys for
  38  * information beyond what licensees probably provide.
  39  *
  40  * The driver has currently been tested only with the Atmel AT32AP7000,
  41  * which does not support descriptor writeback.
  42  */
  43
  44 static inline unsigned int dwc_get_dms(struct dw_dma_slave *slave)
  45 {
  46         return slave ? slave->dst_master : 0;
  47 }
  48
  49 static inline unsigned int dwc_get_sms(struct dw_dma_slave *slave)
  50 {
  51         return slave ? slave->src_master : 1;
  52 }
  53
  54 static inline void dwc_set_masters(struct dw_dma_chan *dwc)
  55 {
  56         struct dw_dma *dw = to_dw_dma(dwc->chan.device);
  57         struct dw_dma_slave *dws = dwc->chan.private;
  58         unsigned char mmax = dw->nr_masters - 1;
  59
  60         if (dwc->request_line == ~0) {
  61                 dwc->src_master = min_t(unsigned char, mmax, dwc_get_sms(dws));
  62                 dwc->dst_master = min_t(unsigned char, mmax, dwc_get_dms(dws));
  63         }
  64 }
  65
  66 #define DWC_DEFAULT_CTLLO(_chan) ({                             \
  67                 struct dw_dma_chan *_dwc = to_dw_dma_chan(_chan);       \
  68                 struct dma_slave_config *_sconfig = &_dwc->dma_sconfig; \
  69                 bool _is_slave = is_slave_direction(_dwc->direction);   \
  70                 u8 _smsize = _is_slave ? _sconfig->src_maxburst :       \
  71                         DW_DMA_MSIZE_16;                        \
  72                 u8 _dmsize = _is_slave ? _sconfig->dst_maxburst :       \
  73                         DW_DMA_MSIZE_16;                        \
  74                                                                 \
  75                 (DWC_CTLL_DST_MSIZE(_dmsize)                    \
  76                  | DWC_CTLL_SRC_MSIZE(_smsize)                  \
  77                  | DWC_CTLL_LLP_D_EN                            \
  78                  | DWC_CTLL_LLP_S_EN                            \
  79                  | DWC_CTLL_DMS(_dwc->dst_master)               \
  80                  | DWC_CTLL_SMS(_dwc->src_master));             \
  81         })
  82
  83 /*
  84  * Number of descriptors to allocate for each channel. This should be
  85  * made configurable somehow; preferably, the clients (at least the
  86  * ones using slave transfers) should be able to give us a hint.
  87  */
  88 #define NR_DESCS_PER_CHANNEL    64
  89
  90 /*----------------------------------------------------------------------*/
  91
  92 static struct device *chan2dev(struct dma_chan *chan)
  93 {
  94         return &chan->dev->device;
  95 }
  96 static struct device *chan2parent(struct dma_chan *chan)
  97 {
  98         return chan->dev->device.parent;
  99 }
 100
 101 static struct dw_desc *dwc_first_active(struct dw_dma_chan *dwc)
 102 {
 103         return to_dw_desc(dwc->active_list.next);
 104 }
 105
 106 static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc)
 107 {
 108         struct dw_desc *desc, *_desc;
 109         struct dw_desc *ret = NULL;
 110         unsigned int i = 0;
 111         unsigned long flags;
 112
 113         spin_lock_irqsave(&dwc->lock, flags);
 114         list_for_each_entry_safe(desc, _desc, &dwc->free_list, desc_node) {
 115                 i++;
 116                 if (async_tx_test_ack(&desc->txd)) {
 117                         list_del(&desc->desc_node);
 118                         ret = desc;
 119                         break;
 120                 }
 121                 dev_dbg(chan2dev(&dwc->chan), "desc %p not ACKed\n", desc);
 122         }
 123         spin_unlock_irqrestore(&dwc->lock, flags);
 124
 125         dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i);
 126
 127         return ret;
 128 }
 129
 130 /*
 131  * Move a descriptor, including any children, to the free list.
 132  * `desc' must not be on any lists.
 133  */
 134 static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
 135 {
 136         unsigned long flags;
 137
 138         if (desc) {
 139                 struct dw_desc *child;
 140
 141                 spin_lock_irqsave(&dwc->lock, flags);
 142                 list_for_each_entry(child, &desc->tx_list, desc_node)
 143                         dev_vdbg(chan2dev(&dwc->chan),
 144                                         "moving child desc %p to freelist\n",
 145                                         child);
 146                 list_splice_init(&desc->tx_list, &dwc->free_list);
 147                 dev_vdbg(chan2dev(&dwc->chan), "moving desc %p to freelist\n", desc);
 148                 list_add(&desc->desc_node, &dwc->free_list);
 149                 spin_unlock_irqrestore(&dwc->lock, flags);
 150         }
 151 }
 152
 153 static void dwc_initialize(struct dw_dma_chan *dwc)
 154 {
 155         struct dw_dma *dw = to_dw_dma(dwc->chan.device);
 156         struct dw_dma_slave *dws = dwc->chan.private;
 157         u32 cfghi = DWC_CFGH_FIFO_MODE;
 158         u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
 159
 160         if (dwc->initialized == true)
 161                 return;
 162
 163         if (dws) {
 164                 /*
 165                  * We need controller-specific data to set up slave
 166                  * transfers.
 167                  */
 168                 BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev);
 169
 170                 cfghi = dws->cfg_hi;
 171                 cfglo |= dws->cfg_lo & ~DWC_CFGL_CH_PRIOR_MASK;
 172         } else {
 173                 if (dwc->direction == DMA_MEM_TO_DEV)
 174                         cfghi = DWC_CFGH_DST_PER(dwc->request_line);
 175                 else if (dwc->direction == DMA_DEV_TO_MEM)
 176                         cfghi = DWC_CFGH_SRC_PER(dwc->request_line);
 177         }
 178
 179         channel_writel(dwc, CFG_LO, cfglo);
 180         channel_writel(dwc, CFG_HI, cfghi);
 181
 182         /* Enable interrupts */
 183         channel_set_bit(dw, MASK.XFER, dwc->mask);
 184         channel_set_bit(dw, MASK.ERROR, dwc->mask);
 185
 186         dwc->initialized = true;
 187 }
 188
 189 /*----------------------------------------------------------------------*/
 190
 191 static inline unsigned int dwc_fast_fls(unsigned long long v)
 192 {
 193         /*
 194          * We can be a lot more clever here, but this should take care
 195          * of the most common optimization.
 196          */
 197         if (!(v & 7))
 198                 return 3;
 199         else if (!(v & 3))
 200                 return 2;
 201         else if (!(v & 1))
 202                 return 1;
 203         return 0;
 204 }
 205
 206 static inline void dwc_dump_chan_regs(struct dw_dma_chan *dwc)
 207 {
 208         dev_err(chan2dev(&dwc->chan),
 209                 "  SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
 210                 channel_readl(dwc, SAR),
 211                 channel_readl(dwc, DAR),
 212                 channel_readl(dwc, LLP),
 213                 channel_readl(dwc, CTL_HI),
 214                 channel_readl(dwc, CTL_LO));
 215 }
 216
 217 static inline void dwc_chan_disable(struct dw_dma *dw, struct dw_dma_chan *dwc)
 218 {
 219         channel_clear_bit(dw, CH_EN, dwc->mask);
 220         while (dma_readl(dw, CH_EN) & dwc->mask)
 221                 cpu_relax();
 222 }
 223
 224 /*----------------------------------------------------------------------*/
 225
 226 /* Perform single block transfer */
 227 static inline void dwc_do_single_block(struct dw_dma_chan *dwc,
 228                                        struct dw_desc *desc)
 229 {
 230         struct dw_dma   *dw = to_dw_dma(dwc->chan.device);
 231         u32             ctllo;
 232
 233         /* Software emulation of LLP mode relies on interrupts to continue
 234          * multi block transfer. */
 235         ctllo = desc->lli.ctllo | DWC_CTLL_INT_EN;
 236
 237         channel_writel(dwc, SAR, desc->lli.sar);
 238         channel_writel(dwc, DAR, desc->lli.dar);
 239         channel_writel(dwc, CTL_LO, ctllo);
 240         channel_writel(dwc, CTL_HI, desc->lli.ctlhi);
 241         channel_set_bit(dw, CH_EN, dwc->mask);
 242
 243         /* Move pointer to next descriptor */
 244         dwc->tx_node_active = dwc->tx_node_active->next;
 245 }
 246
 247 /* Called with dwc->lock held and bh disabled */
 248 static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
 249 {
 250         struct dw_dma   *dw = to_dw_dma(dwc->chan.device);
 251         unsigned long   was_soft_llp;
 252
 253         /* ASSERT:  channel is idle */
 254         if (dma_readl(dw, CH_EN) & dwc->mask) {
 255                 dev_err(chan2dev(&dwc->chan),
 256                         "BUG: Attempted to start non-idle channel\n");
 257                 dwc_dump_chan_regs(dwc);
 258
 259                 /* The tasklet will hopefully advance the queue... */
 260                 return;
 261         }
 262
 263         if (dwc->nollp) {
 264                 was_soft_llp = test_and_set_bit(DW_DMA_IS_SOFT_LLP,
 265                                                 &dwc->flags);
 266                 if (was_soft_llp) {
 267                         dev_err(chan2dev(&dwc->chan),
 268                                 "BUG: Attempted to start new LLP transfer "
 269                                 "inside ongoing one\n");
 270                         return;
 271                 }
 272
 273                 dwc_initialize(dwc);
 274
 275                 dwc->residue = first->total_len;
 276                 dwc->tx_node_active = &first->tx_list;
 277
 278                 /* Submit first block */
 279                 dwc_do_single_block(dwc, first);
 280
 281                 return;
 282         }
 283
 284         dwc_initialize(dwc);
 285
 286         channel_writel(dwc, LLP, first->txd.phys);
 287         channel_writel(dwc, CTL_LO,
 288                         DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
 289         channel_writel(dwc, CTL_HI, 0);
 290         channel_set_bit(dw, CH_EN, dwc->mask);
 291 }
 292
 293 /*----------------------------------------------------------------------*/
 294
 295 static void
 296 dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc,
 297                 bool callback_required)
 298 {
 299         dma_async_tx_callback           callback = NULL;
 300         void                            *param = NULL;
 301         struct dma_async_tx_descriptor  *txd = &desc->txd;
 302         struct dw_desc                  *child;
 303         unsigned long                   flags;
 304
 305         dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
 306
 307         spin_lock_irqsave(&dwc->lock, flags);
 308         dma_cookie_complete(txd);
 309         if (callback_required) {
 310                 callback = txd->callback;
 311                 param = txd->callback_param;
 312         }
 313
 314         /* async_tx_ack */
 315         list_for_each_entry(child, &desc->tx_list, desc_node)
 316                 async_tx_ack(&child->txd);
 317         async_tx_ack(&desc->txd);
 318
 319         list_splice_init(&desc->tx_list, &dwc->free_list);
 320         list_move(&desc->desc_node, &dwc->free_list);
 321
 322         if (!is_slave_direction(dwc->direction)) {
 323                 struct device *parent = chan2parent(&dwc->chan);
 324                 if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
 325                         if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
 326                                 dma_unmap_single(parent, desc->lli.dar,
 327                                         desc->total_len, DMA_FROM_DEVICE);
 328                         else
 329                                 dma_unmap_page(parent, desc->lli.dar,
 330                                         desc->total_len, DMA_FROM_DEVICE);
 331                 }
 332                 if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
 333                         if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
 334                                 dma_unmap_single(parent, desc->lli.sar,
 335                                         desc->total_len, DMA_TO_DEVICE);
 336                         else
 337                                 dma_unmap_page(parent, desc->lli.sar,
 338                                         desc->total_len, DMA_TO_DEVICE);
 339                 }
 340         }
 341
 342         spin_unlock_irqrestore(&dwc->lock, flags);
 343
 344         if (callback)
 345                 callback(param);
 346 }
 347
 348 static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
 349 {
 350         struct dw_desc *desc, *_desc;
 351         LIST_HEAD(list);
 352         unsigned long flags;
 353
 354         spin_lock_irqsave(&dwc->lock, flags);
 355         if (dma_readl(dw, CH_EN) & dwc->mask) {
 356                 dev_err(chan2dev(&dwc->chan),
 357                         "BUG: XFER bit set, but channel not idle!\n");
 358
 359                 /* Try to continue after resetting the channel... */
 360                 dwc_chan_disable(dw, dwc);
 361         }
 362
 363         /*
 364          * Submit queued descriptors ASAP, i.e. before we go through
 365          * the completed ones.
 366          */
 367         list_splice_init(&dwc->active_list, &list);
 368         if (!list_empty(&dwc->queue)) {
 369                 list_move(dwc->queue.next, &dwc->active_list);
 370                 dwc_dostart(dwc, dwc_first_active(dwc));
 371         }
 372
 373         spin_unlock_irqrestore(&dwc->lock, flags);
 374
 375         list_for_each_entry_safe(desc, _desc, &list, desc_node)
 376                 dwc_descriptor_complete(dwc, desc, true);
 377 }
 378
 379 /* Returns how many bytes were already received from source */
 380 static inline u32 dwc_get_sent(struct dw_dma_chan *dwc)
 381 {
 382         u32 ctlhi = channel_readl(dwc, CTL_HI);
 383         u32 ctllo = channel_readl(dwc, CTL_LO);
 384
 385         return (ctlhi & DWC_CTLH_BLOCK_TS_MASK) * (1 << (ctllo >> 4 & 7));
 386 }
 387
 388 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
 389 {
 390         dma_addr_t llp;
 391         struct dw_desc *desc, *_desc;
 392         struct dw_desc *child;
 393         u32 status_xfer;
 394         unsigned long flags;
 395
 396         spin_lock_irqsave(&dwc->lock, flags);
 397         llp = channel_readl(dwc, LLP);
 398         status_xfer = dma_readl(dw, RAW.XFER);
 399
 400         if (status_xfer & dwc->mask) {
 401                 /* Everything we've submitted is done */
 402                 dma_writel(dw, CLEAR.XFER, dwc->mask);
 403
 404                 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
 405                         struct list_head *head, *active = dwc->tx_node_active;
 406
 407                         /*
 408                          * We are inside first active descriptor.
 409                          * Otherwise something is really wrong.
 410                          */
 411                         desc = dwc_first_active(dwc);
 412
 413                         head = &desc->tx_list;
 414                         if (active != head) {
 415                                 /* Update desc to reflect last sent one */
 416                                 if (active != head->next)
 417                                         desc = to_dw_desc(active->prev);
 418
 419                                 dwc->residue -= desc->len;
 420
 421                                 child = to_dw_desc(active);
 422
 423                                 /* Submit next block */
 424                                 dwc_do_single_block(dwc, child);
 425
 426                                 spin_unlock_irqrestore(&dwc->lock, flags);
 427                                 return;
 428                         }
 429
 430                         /* We are done here */
 431                         clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
 432                 }
 433
 434                 dwc->residue = 0;
 435
 436                 spin_unlock_irqrestore(&dwc->lock, flags);
 437
 438                 dwc_complete_all(dw, dwc);
 439                 return;
 440         }
 441
 442         if (list_empty(&dwc->active_list)) {
 443                 dwc->residue = 0;
 444                 spin_unlock_irqrestore(&dwc->lock, flags);
 445                 return;
 446         }
 447
 448         if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
 449                 dev_vdbg(chan2dev(&dwc->chan), "%s: soft LLP mode\n", __func__);
 450                 spin_unlock_irqrestore(&dwc->lock, flags);
 451                 return;
 452         }
 453
 454         dev_vdbg(chan2dev(&dwc->chan), "%s: llp=0x%llx\n", __func__,
 455                         (unsigned long long)llp);
 456
 457         list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
 458                 /* Initial residue value */
 459                 dwc->residue = desc->total_len;
 460
 461                 /* Check first descriptors addr */
 462                 if (desc->txd.phys == llp) {
 463                         spin_unlock_irqrestore(&dwc->lock, flags);
 464                         return;
 465                 }
 466
 467                 /* Check first descriptors llp */
 468                 if (desc->lli.llp == llp) {
 469                         /* This one is currently in progress */
 470                         dwc->residue -= dwc_get_sent(dwc);
 471                         spin_unlock_irqrestore(&dwc->lock, flags);
 472                         return;
 473                 }
 474
 475                 dwc->residue -= desc->len;
 476                 list_for_each_entry(child, &desc->tx_list, desc_node) {
 477                         if (child->lli.llp == llp) {
 478                                 /* Currently in progress */
 479                                 dwc->residue -= dwc_get_sent(dwc);
 480                                 spin_unlock_irqrestore(&dwc->lock, flags);
 481                                 return;
 482                         }
 483                         dwc->residue -= child->len;
 484                 }
 485
 486                 /*
 487                  * No descriptors so far seem to be in progress, i.e.
 488                  * this one must be done.
 489                  */
 490                 spin_unlock_irqrestore(&dwc->lock, flags);
 491                 dwc_descriptor_complete(dwc, desc, true);
 492                 spin_lock_irqsave(&dwc->lock, flags);
 493         }
 494
 495         dev_err(chan2dev(&dwc->chan),
 496                 "BUG: All descriptors done, but channel not idle!\n");
 497
 498         /* Try to continue after resetting the channel... */
 499         dwc_chan_disable(dw, dwc);
 500
 501         if (!list_empty(&dwc->queue)) {
 502                 list_move(dwc->queue.next, &dwc->active_list);
 503                 dwc_dostart(dwc, dwc_first_active(dwc));
 504         }
 505         spin_unlock_irqrestore(&dwc->lock, flags);
 506 }
 507
 508 static inline void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli)
 509 {
 510         dev_crit(chan2dev(&dwc->chan), "  desc: s0x%x d0x%x l0x%x c0x%x:%x\n",
 511                  lli->sar, lli->dar, lli->llp, lli->ctlhi, lli->ctllo);
 512 }
 513
 514 static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
 515 {
 516         struct dw_desc *bad_desc;
 517         struct dw_desc *child;
 518         unsigned long flags;
 519
 520         dwc_scan_descriptors(dw, dwc);
 521
 522         spin_lock_irqsave(&dwc->lock, flags);
 523
 524         /*
 525          * The descriptor currently at the head of the active list is
 526          * borked. Since we don't have any way to report errors, we'll
 527          * just have to scream loudly and try to carry on.
 528          */
 529         bad_desc = dwc_first_active(dwc);
 530         list_del_init(&bad_desc->desc_node);
 531         list_move(dwc->queue.next, dwc->active_list.prev);
 532
 533         /* Clear the error flag and try to restart the controller */
 534         dma_writel(dw, CLEAR.ERROR, dwc->mask);
 535         if (!list_empty(&dwc->active_list))
 536                 dwc_dostart(dwc, dwc_first_active(dwc));
 537
 538         /*
 539          * WARN may seem harsh, but since this only happens
 540          * when someone submits a bad physical address in a
 541          * descriptor, we should consider ourselves lucky that the
 542          * controller flagged an error instead of scribbling over
 543          * random memory locations.
 544          */
 545         dev_WARN(chan2dev(&dwc->chan), "Bad descriptor submitted for DMA!\n"
 546                                        "  cookie: %d\n", bad_desc->txd.cookie);
 547         dwc_dump_lli(dwc, &bad_desc->lli);
 548         list_for_each_entry(child, &bad_desc->tx_list, desc_node)
 549                 dwc_dump_lli(dwc, &child->lli);
 550
 551         spin_unlock_irqrestore(&dwc->lock, flags);
 552
 553         /* Pretend the descriptor completed successfully */
 554         dwc_descriptor_complete(dwc, bad_desc, true);
 555 }
 556
 557 /* --------------------- Cyclic DMA API extensions -------------------- */
 558
 559 inline dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan)
 560 {
 561         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 562         return channel_readl(dwc, SAR);
 563 }
 564 EXPORT_SYMBOL(dw_dma_get_src_addr);
 565
 566 inline dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan)
 567 {
 568         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 569         return channel_readl(dwc, DAR);
 570 }
 571 EXPORT_SYMBOL(dw_dma_get_dst_addr);
 572
 573 /* Called with dwc->lock held and all DMAC interrupts disabled */
 574 static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
 575                 u32 status_err, u32 status_xfer)
 576 {
 577         unsigned long flags;
 578
 579         if (dwc->mask) {
 580                 void (*callback)(void *param);
 581                 void *callback_param;
 582
 583                 dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp 0x%08x\n",
 584                                 channel_readl(dwc, LLP));
 585
 586                 callback = dwc->cdesc->period_callback;
 587                 callback_param = dwc->cdesc->period_callback_param;
 588
 589                 if (callback)
 590                         callback(callback_param);
 591         }
 592
 593         /*
 594          * Error and transfer complete are highly unlikely, and will most
 595          * likely be due to a configuration error by the user.
 596          */
 597         if (unlikely(status_err & dwc->mask) ||
 598                         unlikely(status_xfer & dwc->mask)) {
 599                 int i;
 600
 601                 dev_err(chan2dev(&dwc->chan), "cyclic DMA unexpected %s "
 602                                 "interrupt, stopping DMA transfer\n",
 603                                 status_xfer ? "xfer" : "error");
 604
 605                 spin_lock_irqsave(&dwc->lock, flags);
 606
 607                 dwc_dump_chan_regs(dwc);
 608
 609                 dwc_chan_disable(dw, dwc);
 610
 611                 /* Make sure DMA does not restart by loading a new list */
 612                 channel_writel(dwc, LLP, 0);
 613                 channel_writel(dwc, CTL_LO, 0);
 614                 channel_writel(dwc, CTL_HI, 0);
 615
 616                 dma_writel(dw, CLEAR.ERROR, dwc->mask);
 617                 dma_writel(dw, CLEAR.XFER, dwc->mask);
 618
 619                 for (i = 0; i < dwc->cdesc->periods; i++)
 620                         dwc_dump_lli(dwc, &dwc->cdesc->desc[i]->lli);
 621
 622                 spin_unlock_irqrestore(&dwc->lock, flags);
 623         }
 624 }
 625
 626 /* ------------------------------------------------------------------------- */
 627
 628 static void dw_dma_tasklet(unsigned long data)
 629 {
 630         struct dw_dma *dw = (struct dw_dma *)data;
 631         struct dw_dma_chan *dwc;
 632         u32 status_xfer;
 633         u32 status_err;
 634         int i;
 635
 636         status_xfer = dma_readl(dw, RAW.XFER);
 637         status_err = dma_readl(dw, RAW.ERROR);
 638
 639         dev_vdbg(dw->dma.dev, "%s: status_err=%x\n", __func__, status_err);
 640
 641         for (i = 0; i < dw->dma.chancnt; i++) {
 642                 dwc = &dw->chan[i];
 643                 if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
 644                         dwc_handle_cyclic(dw, dwc, status_err, status_xfer);
 645                 else if (status_err & (1 << i))
 646                         dwc_handle_error(dw, dwc);
 647                 else if (status_xfer & (1 << i))
 648                         dwc_scan_descriptors(dw, dwc);
 649         }
 650
 651         /*
 652          * Re-enable interrupts.
 653          */
 654         channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
 655         channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask);
 656 }
 657
 658 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
 659 {
 660         struct dw_dma *dw = dev_id;
 661         u32 status;
 662
 663         dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__,
 664                         dma_readl(dw, STATUS_INT));
 665
 666         /*
 667          * Just disable the interrupts. We'll turn them back on in the
 668          * softirq handler.
 669          */
 670         channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
 671         channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
 672
 673         status = dma_readl(dw, STATUS_INT);
 674         if (status) {
 675                 dev_err(dw->dma.dev,
 676                         "BUG: Unexpected interrupts pending: 0x%x\n",
 677                         status);
 678
 679                 /* Try to recover */
 680                 channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1);
 681                 channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1);
 682                 channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1);
 683                 channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1);
 684         }
 685
 686         tasklet_schedule(&dw->tasklet);
 687
 688         return IRQ_HANDLED;
 689 }
 690
 691 /*----------------------------------------------------------------------*/
 692
 693 static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
 694 {
 695         struct dw_desc          *desc = txd_to_dw_desc(tx);
 696         struct dw_dma_chan      *dwc = to_dw_dma_chan(tx->chan);
 697         dma_cookie_t            cookie;
 698         unsigned long           flags;
 699
 700         spin_lock_irqsave(&dwc->lock, flags);
 701         cookie = dma_cookie_assign(tx);
 702
 703         /*
 704          * REVISIT: We should attempt to chain as many descriptors as
 705          * possible, perhaps even appending to those already submitted
 706          * for DMA. But this is hard to do in a race-free manner.
 707          */
 708         if (list_empty(&dwc->active_list)) {
 709                 dev_vdbg(chan2dev(tx->chan), "%s: started %u\n", __func__,
 710                                 desc->txd.cookie);
 711                 list_add_tail(&desc->desc_node, &dwc->active_list);
 712                 dwc_dostart(dwc, dwc_first_active(dwc));
 713         } else {
 714                 dev_vdbg(chan2dev(tx->chan), "%s: queued %u\n", __func__,
 715                                 desc->txd.cookie);
 716
 717                 list_add_tail(&desc->desc_node, &dwc->queue);
 718         }
 719
 720         spin_unlock_irqrestore(&dwc->lock, flags);
 721
 722         return cookie;
 723 }
 724
 725 static struct dma_async_tx_descriptor *
 726 dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 727                 size_t len, unsigned long flags)
 728 {
 729         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 730         struct dw_dma           *dw = to_dw_dma(chan->device);
 731         struct dw_desc          *desc;
 732         struct dw_desc          *first;
 733         struct dw_desc          *prev;
 734         size_t                  xfer_count;
 735         size_t                  offset;
 736         unsigned int            src_width;
 737         unsigned int            dst_width;
 738         unsigned int            data_width;
 739         u32                     ctllo;
 740
 741         dev_vdbg(chan2dev(chan),
 742                         "%s: d0x%llx s0x%llx l0x%zx f0x%lx\n", __func__,
 743                         (unsigned long long)dest, (unsigned long long)src,
 744                         len, flags);
 745
 746         if (unlikely(!len)) {
 747                 dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__);
 748                 return NULL;
 749         }
 750
 751         dwc->direction = DMA_MEM_TO_MEM;
 752
 753         data_width = min_t(unsigned int, dw->data_width[dwc->src_master],
 754                            dw->data_width[dwc->dst_master]);
 755
 756         src_width = dst_width = min_t(unsigned int, data_width,
 757                                       dwc_fast_fls(src | dest | len));
 758
 759         ctllo = DWC_DEFAULT_CTLLO(chan)
 760                         | DWC_CTLL_DST_WIDTH(dst_width)
 761                         | DWC_CTLL_SRC_WIDTH(src_width)
 762                         | DWC_CTLL_DST_INC
 763                         | DWC_CTLL_SRC_INC
 764                         | DWC_CTLL_FC_M2M;
 765         prev = first = NULL;
 766
 767         for (offset = 0; offset < len; offset += xfer_count << src_width) {
 768                 xfer_count = min_t(size_t, (len - offset) >> src_width,
 769                                            dwc->block_size);
 770
 771                 desc = dwc_desc_get(dwc);
 772                 if (!desc)
 773                         goto err_desc_get;
 774
 775                 desc->lli.sar = src + offset;
 776                 desc->lli.dar = dest + offset;
 777                 desc->lli.ctllo = ctllo;
 778                 desc->lli.ctlhi = xfer_count;
 779                 desc->len = xfer_count << src_width;
 780
 781                 if (!first) {
 782                         first = desc;
 783                 } else {
 784                         prev->lli.llp = desc->txd.phys;
 785                         list_add_tail(&desc->desc_node,
 786                                         &first->tx_list);
 787                 }
 788                 prev = desc;
 789         }
 790
 791         if (flags & DMA_PREP_INTERRUPT)
 792                 /* Trigger interrupt after last block */
 793                 prev->lli.ctllo |= DWC_CTLL_INT_EN;
 794
 795         prev->lli.llp = 0;
 796         first->txd.flags = flags;
 797         first->total_len = len;
 798
 799         return &first->txd;
 800
 801 err_desc_get:
 802         dwc_desc_put(dwc, first);
 803         return NULL;
 804 }
 805
 806 static struct dma_async_tx_descriptor *
 807 dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 808                 unsigned int sg_len, enum dma_transfer_direction direction,
 809                 unsigned long flags, void *context)
 810 {
 811         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 812         struct dw_dma           *dw = to_dw_dma(chan->device);
 813         struct dma_slave_config *sconfig = &dwc->dma_sconfig;
 814         struct dw_desc          *prev;
 815         struct dw_desc          *first;
 816         u32                     ctllo;
 817         dma_addr_t              reg;
 818         unsigned int            reg_width;
 819         unsigned int            mem_width;
 820         unsigned int            data_width;
 821         unsigned int            i;
 822         struct scatterlist      *sg;
 823         size_t                  total_len = 0;
 824
 825         dev_vdbg(chan2dev(chan), "%s\n", __func__);
 826
 827         if (unlikely(!is_slave_direction(direction) || !sg_len))
 828                 return NULL;
 829
 830         dwc->direction = direction;
 831
 832         prev = first = NULL;
 833
 834         switch (direction) {
 835         case DMA_MEM_TO_DEV:
 836                 reg_width = __fls(sconfig->dst_addr_width);
 837                 reg = sconfig->dst_addr;
 838                 ctllo = (DWC_DEFAULT_CTLLO(chan)
 839                                 | DWC_CTLL_DST_WIDTH(reg_width)
 840                                 | DWC_CTLL_DST_FIX
 841                                 | DWC_CTLL_SRC_INC);
 842
 843                 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
 844                         DWC_CTLL_FC(DW_DMA_FC_D_M2P);
 845
 846                 data_width = dw->data_width[dwc->src_master];
 847
 848                 for_each_sg(sgl, sg, sg_len, i) {
 849                         struct dw_desc  *desc;
 850                         u32             len, dlen, mem;
 851
 852                         mem = sg_dma_address(sg);
 853                         len = sg_dma_len(sg);
 854
 855                         mem_width = min_t(unsigned int,
 856                                           data_width, dwc_fast_fls(mem | len));
 857
 858 slave_sg_todev_fill_desc:
 859                         desc = dwc_desc_get(dwc);
 860                         if (!desc) {
 861                                 dev_err(chan2dev(chan),
 862                                         "not enough descriptors available\n");
 863                                 goto err_desc_get;
 864                         }
 865
 866                         desc->lli.sar = mem;
 867                         desc->lli.dar = reg;
 868                         desc->lli.ctllo = ctllo | DWC_CTLL_SRC_WIDTH(mem_width);
 869                         if ((len >> mem_width) > dwc->block_size) {
 870                                 dlen = dwc->block_size << mem_width;
 871                                 mem += dlen;
 872                                 len -= dlen;
 873                         } else {
 874                                 dlen = len;
 875                                 len = 0;
 876                         }
 877
 878                         desc->lli.ctlhi = dlen >> mem_width;
 879                         desc->len = dlen;
 880
 881                         if (!first) {
 882                                 first = desc;
 883                         } else {
 884                                 prev->lli.llp = desc->txd.phys;
 885                                 list_add_tail(&desc->desc_node,
 886                                                 &first->tx_list);
 887                         }
 888                         prev = desc;
 889                         total_len += dlen;
 890
 891                         if (len)
 892                                 goto slave_sg_todev_fill_desc;
 893                 }
 894                 break;
 895         case DMA_DEV_TO_MEM:
 896                 reg_width = __fls(sconfig->src_addr_width);
 897                 reg = sconfig->src_addr;
 898                 ctllo = (DWC_DEFAULT_CTLLO(chan)
 899                                 | DWC_CTLL_SRC_WIDTH(reg_width)
 900                                 | DWC_CTLL_DST_INC
 901                                 | DWC_CTLL_SRC_FIX);
 902
 903                 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
 904                         DWC_CTLL_FC(DW_DMA_FC_D_P2M);
 905
 906                 data_width = dw->data_width[dwc->dst_master];
 907
 908                 for_each_sg(sgl, sg, sg_len, i) {
 909                         struct dw_desc  *desc;
 910                         u32             len, dlen, mem;
 911
 912                         mem = sg_dma_address(sg);
 913                         len = sg_dma_len(sg);
 914
 915                         mem_width = min_t(unsigned int,
 916                                           data_width, dwc_fast_fls(mem | len));
 917
 918 slave_sg_fromdev_fill_desc:
 919                         desc = dwc_desc_get(dwc);
 920                         if (!desc) {
 921                                 dev_err(chan2dev(chan),
 922                                                 "not enough descriptors available\n");
 923                                 goto err_desc_get;
 924                         }
 925
 926                         desc->lli.sar = reg;
 927                         desc->lli.dar = mem;
 928                         desc->lli.ctllo = ctllo | DWC_CTLL_DST_WIDTH(mem_width);
 929                         if ((len >> reg_width) > dwc->block_size) {
 930                                 dlen = dwc->block_size << reg_width;
 931                                 mem += dlen;
 932                                 len -= dlen;
 933                         } else {
 934                                 dlen = len;
 935                                 len = 0;
 936                         }
 937                         desc->lli.ctlhi = dlen >> reg_width;
 938                         desc->len = dlen;
 939
 940                         if (!first) {
 941                                 first = desc;
 942                         } else {
 943                                 prev->lli.llp = desc->txd.phys;
 944                                 list_add_tail(&desc->desc_node,
 945                                                 &first->tx_list);
 946                         }
 947                         prev = desc;
 948                         total_len += dlen;
 949
 950                         if (len)
 951                                 goto slave_sg_fromdev_fill_desc;
 952                 }
 953                 break;
 954         default:
 955                 return NULL;
 956         }
 957
 958         if (flags & DMA_PREP_INTERRUPT)
 959                 /* Trigger interrupt after last block */
 960                 prev->lli.ctllo |= DWC_CTLL_INT_EN;
 961
 962         prev->lli.llp = 0;
 963         first->total_len = total_len;
 964
 965         return &first->txd;
 966
 967 err_desc_get:
 968         dwc_desc_put(dwc, first);
 969         return NULL;
 970 }
 971
 972 /*
 973  * Fix sconfig's burst size according to dw_dmac. We need to convert them as:
 974  * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
 975  *
 976  * NOTE: burst size 2 is not supported by controller.
 977  *
 978  * This can be done by finding least significant bit set: n & (n - 1)
 979  */
 980 static inline void convert_burst(u32 *maxburst)
 981 {
 982         if (*maxburst > 1)
 983                 *maxburst = fls(*maxburst) - 2;
 984         else
 985                 *maxburst = 0;
 986 }
 987
 988 static int
 989 set_runtime_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
 990 {
 991         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 992
 993         /* Check if chan will be configured for slave transfers */
 994         if (!is_slave_direction(sconfig->direction))
 995                 return -EINVAL;
 996
 997         memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig));
 998         dwc->direction = sconfig->direction;
 999
1000         /* Take the request line from slave_id member */
1001         if (dwc->request_line == ~0)
1002                 dwc->request_line = sconfig->slave_id;
1003
1004         convert_burst(&dwc->dma_sconfig.src_maxburst);
1005         convert_burst(&dwc->dma_sconfig.dst_maxburst);
1006
1007         return 0;
1008 }
1009
1010 static inline void dwc_chan_pause(struct dw_dma_chan *dwc)
1011 {
1012         u32 cfglo = channel_readl(dwc, CFG_LO);
1013         unsigned int count = 20;        /* timeout iterations */
1014
1015         channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
1016         while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY) && count--)
1017                 udelay(2);
1018
1019         dwc->paused = true;
1020 }
1021
1022 static inline void dwc_chan_resume(struct dw_dma_chan *dwc)
1023 {
1024         u32 cfglo = channel_readl(dwc, CFG_LO);
1025
1026         channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
1027
1028         dwc->paused = false;
1029 }
1030
1031 static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
1032                        unsigned long arg)
1033 {
1034         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1035         struct dw_dma           *dw = to_dw_dma(chan->device);
1036         struct dw_desc          *desc, *_desc;
1037         unsigned long           flags;
1038         LIST_HEAD(list);
1039
1040         if (cmd == DMA_PAUSE) {
1041                 spin_lock_irqsave(&dwc->lock, flags);
1042
1043                 dwc_chan_pause(dwc);
1044
1045                 spin_unlock_irqrestore(&dwc->lock, flags);
1046         } else if (cmd == DMA_RESUME) {
1047                 if (!dwc->paused)
1048                         return 0;
1049
1050                 spin_lock_irqsave(&dwc->lock, flags);
1051
1052                 dwc_chan_resume(dwc);
1053
1054                 spin_unlock_irqrestore(&dwc->lock, flags);
1055         } else if (cmd == DMA_TERMINATE_ALL) {
1056                 spin_lock_irqsave(&dwc->lock, flags);
1057
1058                 clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
1059
1060                 dwc_chan_disable(dw, dwc);
1061
1062                 dwc_chan_resume(dwc);
1063
1064                 /* active_list entries will end up before queued entries */
1065                 list_splice_init(&dwc->queue, &list);
1066                 list_splice_init(&dwc->active_list, &list);
1067
1068                 spin_unlock_irqrestore(&dwc->lock, flags);
1069
1070                 /* Flush all pending and queued descriptors */
1071                 list_for_each_entry_safe(desc, _desc, &list, desc_node)
1072                         dwc_descriptor_complete(dwc, desc, false);
1073         } else if (cmd == DMA_SLAVE_CONFIG) {
1074                 return set_runtime_config(chan, (struct dma_slave_config *)arg);
1075         } else {
1076                 return -ENXIO;
1077         }
1078
1079         return 0;
1080 }
1081
1082 static inline u32 dwc_get_residue(struct dw_dma_chan *dwc)
1083 {
1084         unsigned long flags;
1085         u32 residue;
1086
1087         spin_lock_irqsave(&dwc->lock, flags);
1088
1089         residue = dwc->residue;
1090         if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags) && residue)
1091                 residue -= dwc_get_sent(dwc);
1092
1093         spin_unlock_irqrestore(&dwc->lock, flags);
1094         return residue;
1095 }
1096
1097 static enum dma_status
1098 dwc_tx_status(struct dma_chan *chan,
1099               dma_cookie_t cookie,
1100               struct dma_tx_state *txstate)
1101 {
1102         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1103         enum dma_status         ret;
1104
1105         ret = dma_cookie_status(chan, cookie, txstate);
1106         if (ret != DMA_SUCCESS) {
1107                 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
1108
1109                 ret = dma_cookie_status(chan, cookie, txstate);
1110         }
1111
1112         if (ret != DMA_SUCCESS)
1113                 dma_set_residue(txstate, dwc_get_residue(dwc));
1114
1115         if (dwc->paused)
1116                 return DMA_PAUSED;
1117
1118         return ret;
1119 }
1120
1121 static void dwc_issue_pending(struct dma_chan *chan)
1122 {
1123         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1124
1125         if (!list_empty(&dwc->queue))
1126                 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
1127 }
1128
1129 static int dwc_alloc_chan_resources(struct dma_chan *chan)
1130 {
1131         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1132         struct dw_dma           *dw = to_dw_dma(chan->device);
1133         struct dw_desc          *desc;
1134         int                     i;
1135         unsigned long           flags;
1136
1137         dev_vdbg(chan2dev(chan), "%s\n", __func__);
1138
1139         /* ASSERT:  channel is idle */
1140         if (dma_readl(dw, CH_EN) & dwc->mask) {
1141                 dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
1142                 return -EIO;
1143         }
1144
1145         dma_cookie_init(chan);
1146
1147         /*
1148          * NOTE: some controllers may have additional features that we
1149          * need to initialize here, like "scatter-gather" (which
1150          * doesn't mean what you think it means), and status writeback.
1151          */
1152
1153         dwc_set_masters(dwc);
1154
1155         spin_lock_irqsave(&dwc->lock, flags);
1156         i = dwc->descs_allocated;
1157         while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) {
1158                 dma_addr_t phys;
1159
1160                 spin_unlock_irqrestore(&dwc->lock, flags);
1161
1162                 desc = dma_pool_alloc(dw->desc_pool, GFP_ATOMIC, &phys);
1163                 if (!desc)
1164                         goto err_desc_alloc;
1165
1166                 memset(desc, 0, sizeof(struct dw_desc));
1167
1168                 INIT_LIST_HEAD(&desc->tx_list);
1169                 dma_async_tx_descriptor_init(&desc->txd, chan);
1170                 desc->txd.tx_submit = dwc_tx_submit;
1171                 desc->txd.flags = DMA_CTRL_ACK;
1172                 desc->txd.phys = phys;
1173
1174                 dwc_desc_put(dwc, desc);
1175
1176                 spin_lock_irqsave(&dwc->lock, flags);
1177                 i = ++dwc->descs_allocated;
1178         }
1179
1180         spin_unlock_irqrestore(&dwc->lock, flags);
1181
1182         dev_dbg(chan2dev(chan), "%s: allocated %d descriptors\n", __func__, i);
1183
1184         return i;
1185
1186 err_desc_alloc:
1187         dev_info(chan2dev(chan), "only allocated %d descriptors\n", i);
1188
1189         return i;
1190 }
1191
1192 static void dwc_free_chan_resources(struct dma_chan *chan)
1193 {
1194         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1195         struct dw_dma           *dw = to_dw_dma(chan->device);
1196         struct dw_desc          *desc, *_desc;
1197         unsigned long           flags;
1198         LIST_HEAD(list);
1199
1200         dev_dbg(chan2dev(chan), "%s: descs allocated=%u\n", __func__,
1201                         dwc->descs_allocated);
1202
1203         /* ASSERT:  channel is idle */
1204         BUG_ON(!list_empty(&dwc->active_list));
1205         BUG_ON(!list_empty(&dwc->queue));
1206         BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
1207
1208         spin_lock_irqsave(&dwc->lock, flags);
1209         list_splice_init(&dwc->free_list, &list);
1210         dwc->descs_allocated = 0;
1211         dwc->initialized = false;
1212         dwc->request_line = ~0;
1213
1214         /* Disable interrupts */
1215         channel_clear_bit(dw, MASK.XFER, dwc->mask);
1216         channel_clear_bit(dw, MASK.ERROR, dwc->mask);
1217
1218         spin_unlock_irqrestore(&dwc->lock, flags);
1219
1220         list_for_each_entry_safe(desc, _desc, &list, desc_node) {
1221                 dev_vdbg(chan2dev(chan), "  freeing descriptor %p\n", desc);
1222                 dma_pool_free(dw->desc_pool, desc, desc->txd.phys);
1223         }
1224
1225         dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
1226 }
1227
1228 /*----------------------------------------------------------------------*/
1229
1230 struct dw_dma_of_filter_args {
1231         struct dw_dma *dw;
1232         unsigned int req;
1233         unsigned int src;
1234         unsigned int dst;
1235 };
1236
1237 static bool dw_dma_of_filter(struct dma_chan *chan, void *param)
1238 {
1239         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1240         struct dw_dma_of_filter_args *fargs = param;
1241
1242         /* Ensure the device matches our channel */
1243         if (chan->device != &fargs->dw->dma)
1244                 return false;
1245
1246         dwc->request_line = fargs->req;
1247         dwc->src_master = fargs->src;
1248         dwc->dst_master = fargs->dst;
1249
1250         return true;
1251 }
1252
1253 static struct dma_chan *dw_dma_of_xlate(struct of_phandle_args *dma_spec,
1254                                         struct of_dma *ofdma)
1255 {
1256         struct dw_dma *dw = ofdma->of_dma_data;
1257         struct dw_dma_of_filter_args fargs = {
1258                 .dw = dw,
1259         };
1260         dma_cap_mask_t cap;
1261
1262         if (dma_spec->args_count != 3)
1263                 return NULL;
1264
1265         fargs.req = dma_spec->args[0];
1266         fargs.src = dma_spec->args[1];
1267         fargs.dst = dma_spec->args[2];
1268
1269         if (WARN_ON(fargs.req >= DW_DMA_MAX_NR_REQUESTS ||
1270                     fargs.src >= dw->nr_masters ||
1271                     fargs.dst >= dw->nr_masters))
1272                 return NULL;
1273
1274         dma_cap_zero(cap);
1275         dma_cap_set(DMA_SLAVE, cap);
1276
1277         /* TODO: there should be a simpler way to do this */
1278         return dma_request_channel(cap, dw_dma_of_filter, &fargs);
1279 }
1280
1281 #ifdef CONFIG_ACPI
1282 static bool dw_dma_acpi_filter(struct dma_chan *chan, void *param)
1283 {
1284         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
1285         struct acpi_dma_spec *dma_spec = param;
1286
1287         if (chan->device->dev != dma_spec->dev ||
1288             chan->chan_id != dma_spec->chan_id)
1289                 return false;
1290
1291         dwc->request_line = dma_spec->slave_id;
1292         dwc->src_master = dwc_get_sms(NULL);
1293         dwc->dst_master = dwc_get_dms(NULL);
1294
1295         return true;
1296 }
1297
1298 static void dw_dma_acpi_controller_register(struct dw_dma *dw)
1299 {
1300         struct device *dev = dw->dma.dev;
1301         struct acpi_dma_filter_info *info;
1302         int ret;
1303
1304         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
1305         if (!info)
1306                 return;
1307
1308         dma_cap_zero(info->dma_cap);
1309         dma_cap_set(DMA_SLAVE, info->dma_cap);
1310         info->filter_fn = dw_dma_acpi_filter;
1311
1312         ret = devm_acpi_dma_controller_register(dev, acpi_dma_simple_xlate,
1313                                                 info);
1314         if (ret)
1315                 dev_err(dev, "could not register acpi_dma_controller\n");
1316 }
1317 #else /* !CONFIG_ACPI */
1318 static inline void dw_dma_acpi_controller_register(struct dw_dma *dw) {}
1319 #endif /* !CONFIG_ACPI */
1320
1321 /* --------------------- Cyclic DMA API extensions -------------------- */
1322
1323 /**
1324  * dw_dma_cyclic_start - start the cyclic DMA transfer
1325  * @chan: the DMA channel to start
1326  *
1327  * Must be called with soft interrupts disabled. Returns zero on success or
1328  * -errno on failure.
1329  */
1330 int dw_dma_cyclic_start(struct dma_chan *chan)
1331 {
1332         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1333         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
1334         unsigned long           flags;
1335
1336         if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
1337                 dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n");
1338                 return -ENODEV;
1339         }
1340
1341         spin_lock_irqsave(&dwc->lock, flags);
1342
1343         /* Assert channel is idle */
1344         if (dma_readl(dw, CH_EN) & dwc->mask) {
1345                 dev_err(chan2dev(&dwc->chan),
1346                         "BUG: Attempted to start non-idle channel\n");
1347                 dwc_dump_chan_regs(dwc);
1348                 spin_unlock_irqrestore(&dwc->lock, flags);
1349                 return -EBUSY;
1350         }
1351
1352         dma_writel(dw, CLEAR.ERROR, dwc->mask);
1353         dma_writel(dw, CLEAR.XFER, dwc->mask);
1354
1355         /* Setup DMAC channel registers */
1356         channel_writel(dwc, LLP, dwc->cdesc->desc[0]->txd.phys);
1357         channel_writel(dwc, CTL_LO, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
1358         channel_writel(dwc, CTL_HI, 0);
1359
1360         channel_set_bit(dw, CH_EN, dwc->mask);
1361
1362         spin_unlock_irqrestore(&dwc->lock, flags);
1363
1364         return 0;
1365 }
1366 EXPORT_SYMBOL(dw_dma_cyclic_start);
1367
1368 /**
1369  * dw_dma_cyclic_stop - stop the cyclic DMA transfer
1370  * @chan: the DMA channel to stop
1371  *
1372  * Must be called with soft interrupts disabled.
1373  */
1374 void dw_dma_cyclic_stop(struct dma_chan *chan)
1375 {
1376         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1377         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
1378         unsigned long           flags;
1379
1380         spin_lock_irqsave(&dwc->lock, flags);
1381
1382         dwc_chan_disable(dw, dwc);
1383
1384         spin_unlock_irqrestore(&dwc->lock, flags);
1385 }
1386 EXPORT_SYMBOL(dw_dma_cyclic_stop);
1387
1388 /**
1389  * dw_dma_cyclic_prep - prepare the cyclic DMA transfer
1390  * @chan: the DMA channel to prepare
1391  * @buf_addr: physical DMA address where the buffer starts
1392  * @buf_len: total number of bytes for the entire buffer
1393  * @period_len: number of bytes for each period
1394  * @direction: transfer direction, to or from device
1395  *
1396  * Must be called before trying to start the transfer. Returns a valid struct
1397  * dw_cyclic_desc if successful or an ERR_PTR(-errno) if not successful.
1398  */
1399 struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
1400                 dma_addr_t buf_addr, size_t buf_len, size_t period_len,
1401                 enum dma_transfer_direction direction)
1402 {
1403         struct dw_dma_chan              *dwc = to_dw_dma_chan(chan);
1404         struct dma_slave_config         *sconfig = &dwc->dma_sconfig;
1405         struct dw_cyclic_desc           *cdesc;
1406         struct dw_cyclic_desc           *retval = NULL;
1407         struct dw_desc                  *desc;
1408         struct dw_desc                  *last = NULL;
1409         unsigned long                   was_cyclic;
1410         unsigned int                    reg_width;
1411         unsigned int                    periods;
1412         unsigned int                    i;
1413         unsigned long                   flags;
1414
1415         spin_lock_irqsave(&dwc->lock, flags);
1416         if (dwc->nollp) {
1417                 spin_unlock_irqrestore(&dwc->lock, flags);
1418                 dev_dbg(chan2dev(&dwc->chan),
1419                                 "channel doesn't support LLP transfers\n");
1420                 return ERR_PTR(-EINVAL);
1421         }
1422
1423         if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) {
1424                 spin_unlock_irqrestore(&dwc->lock, flags);
1425                 dev_dbg(chan2dev(&dwc->chan),
1426                                 "queue and/or active list are not empty\n");
1427                 return ERR_PTR(-EBUSY);
1428         }
1429
1430         was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1431         spin_unlock_irqrestore(&dwc->lock, flags);
1432         if (was_cyclic) {
1433                 dev_dbg(chan2dev(&dwc->chan),
1434                                 "channel already prepared for cyclic DMA\n");
1435                 return ERR_PTR(-EBUSY);
1436         }
1437
1438         retval = ERR_PTR(-EINVAL);
1439
1440         if (unlikely(!is_slave_direction(direction)))
1441                 goto out_err;
1442
1443         dwc->direction = direction;
1444
1445         if (direction == DMA_MEM_TO_DEV)
1446                 reg_width = __ffs(sconfig->dst_addr_width);
1447         else
1448                 reg_width = __ffs(sconfig->src_addr_width);
1449
1450         periods = buf_len / period_len;
1451
1452         /* Check for too big/unaligned periods and unaligned DMA buffer. */
1453         if (period_len > (dwc->block_size << reg_width))
1454                 goto out_err;
1455         if (unlikely(period_len & ((1 << reg_width) - 1)))
1456                 goto out_err;
1457         if (unlikely(buf_addr & ((1 << reg_width) - 1)))
1458                 goto out_err;
1459
1460         retval = ERR_PTR(-ENOMEM);
1461
1462         if (periods > NR_DESCS_PER_CHANNEL)
1463                 goto out_err;
1464
1465         cdesc = kzalloc(sizeof(struct dw_cyclic_desc), GFP_KERNEL);
1466         if (!cdesc)
1467                 goto out_err;
1468
1469         cdesc->desc = kzalloc(sizeof(struct dw_desc *) * periods, GFP_KERNEL);
1470         if (!cdesc->desc)
1471                 goto out_err_alloc;
1472
1473         for (i = 0; i < periods; i++) {
1474                 desc = dwc_desc_get(dwc);
1475                 if (!desc)
1476                         goto out_err_desc_get;
1477
1478                 switch (direction) {
1479                 case DMA_MEM_TO_DEV:
1480                         desc->lli.dar = sconfig->dst_addr;
1481                         desc->lli.sar = buf_addr + (period_len * i);
1482                         desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan)
1483                                         | DWC_CTLL_DST_WIDTH(reg_width)
1484                                         | DWC_CTLL_SRC_WIDTH(reg_width)
1485                                         | DWC_CTLL_DST_FIX
1486                                         | DWC_CTLL_SRC_INC
1487                                         | DWC_CTLL_INT_EN);
1488
1489                         desc->lli.ctllo |= sconfig->device_fc ?
1490                                 DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
1491                                 DWC_CTLL_FC(DW_DMA_FC_D_M2P);
1492
1493                         break;
1494                 case DMA_DEV_TO_MEM:
1495                         desc->lli.dar = buf_addr + (period_len * i);
1496                         desc->lli.sar = sconfig->src_addr;
1497                         desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan)
1498                                         | DWC_CTLL_SRC_WIDTH(reg_width)
1499                                         | DWC_CTLL_DST_WIDTH(reg_width)
1500                                         | DWC_CTLL_DST_INC
1501                                         | DWC_CTLL_SRC_FIX
1502                                         | DWC_CTLL_INT_EN);
1503
1504                         desc->lli.ctllo |= sconfig->device_fc ?
1505                                 DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
1506                                 DWC_CTLL_FC(DW_DMA_FC_D_P2M);
1507
1508                         break;
1509                 default:
1510                         break;
1511                 }
1512
1513                 desc->lli.ctlhi = (period_len >> reg_width);
1514                 cdesc->desc[i] = desc;
1515
1516                 if (last)
1517                         last->lli.llp = desc->txd.phys;
1518
1519                 last = desc;
1520         }
1521
1522         /* Let's make a cyclic list */
1523         last->lli.llp = cdesc->desc[0]->txd.phys;
1524
1525         dev_dbg(chan2dev(&dwc->chan), "cyclic prepared buf 0x%llx len %zu "
1526                         "period %zu periods %d\n", (unsigned long long)buf_addr,
1527                         buf_len, period_len, periods);
1528
1529         cdesc->periods = periods;
1530         dwc->cdesc = cdesc;
1531
1532         return cdesc;
1533
1534 out_err_desc_get:
1535         while (i--)
1536                 dwc_desc_put(dwc, cdesc->desc[i]);
1537 out_err_alloc:
1538         kfree(cdesc);
1539 out_err:
1540         clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1541         return (struct dw_cyclic_desc *)retval;
1542 }
1543 EXPORT_SYMBOL(dw_dma_cyclic_prep);
1544
1545 /**
1546  * dw_dma_cyclic_free - free a prepared cyclic DMA transfer
1547  * @chan: the DMA channel to free
1548  */
1549 void dw_dma_cyclic_free(struct dma_chan *chan)
1550 {
1551         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1552         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
1553         struct dw_cyclic_desc   *cdesc = dwc->cdesc;
1554         int                     i;
1555         unsigned long           flags;
1556
1557         dev_dbg(chan2dev(&dwc->chan), "%s\n", __func__);
1558
1559         if (!cdesc)
1560                 return;
1561
1562         spin_lock_irqsave(&dwc->lock, flags);
1563
1564         dwc_chan_disable(dw, dwc);
1565
1566         dma_writel(dw, CLEAR.ERROR, dwc->mask);
1567         dma_writel(dw, CLEAR.XFER, dwc->mask);
1568
1569         spin_unlock_irqrestore(&dwc->lock, flags);
1570
1571         for (i = 0; i < cdesc->periods; i++)
1572                 dwc_desc_put(dwc, cdesc->desc[i]);
1573
1574         kfree(cdesc->desc);
1575         kfree(cdesc);
1576
1577         clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1578 }
1579 EXPORT_SYMBOL(dw_dma_cyclic_free);
1580
1581 /*----------------------------------------------------------------------*/
1582
1583 static void dw_dma_off(struct dw_dma *dw)
1584 {
1585         int i;
1586
1587         dma_writel(dw, CFG, 0);
1588
1589         channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1590         channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1591         channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1592         channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1593
1594         while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
1595                 cpu_relax();
1596
1597         for (i = 0; i < dw->dma.chancnt; i++)
1598                 dw->chan[i].initialized = false;
1599 }
1600
1601 #ifdef CONFIG_OF
1602 static struct dw_dma_platform_data *
1603 dw_dma_parse_dt(struct platform_device *pdev)
1604 {
1605         struct device_node *np = pdev->dev.of_node;
1606         struct dw_dma_platform_data *pdata;
1607         u32 tmp, arr[4];
1608
1609         if (!np) {
1610                 dev_err(&pdev->dev, "Missing DT data\n");
1611                 return NULL;
1612         }
1613
1614         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
1615         if (!pdata)
1616                 return NULL;
1617
1618         if (of_property_read_u32(np, "dma-channels", &pdata->nr_channels))
1619                 return NULL;
1620
1621         if (of_property_read_bool(np, "is_private"))
1622                 pdata->is_private = true;
1623
1624         if (!of_property_read_u32(np, "chan_allocation_order", &tmp))
1625                 pdata->chan_allocation_order = (unsigned char)tmp;
1626
1627         if (!of_property_read_u32(np, "chan_priority", &tmp))
1628                 pdata->chan_priority = tmp;
1629
1630         if (!of_property_read_u32(np, "block_size", &tmp))
1631                 pdata->block_size = tmp;
1632
1633         if (!of_property_read_u32(np, "dma-masters", &tmp)) {
1634                 if (tmp > 4)
1635                         return NULL;
1636
1637                 pdata->nr_masters = tmp;
1638         }
1639
1640         if (!of_property_read_u32_array(np, "data_width", arr,
1641                                 pdata->nr_masters))
1642                 for (tmp = 0; tmp < pdata->nr_masters; tmp++)
1643                         pdata->data_width[tmp] = arr[tmp];
1644
1645         return pdata;
1646 }
1647 #else
1648 static inline struct dw_dma_platform_data *
1649 dw_dma_parse_dt(struct platform_device *pdev)
1650 {
1651         return NULL;
1652 }
1653 #endif
1654
1655 static int dw_probe(struct platform_device *pdev)
1656 {
1657         struct dw_dma_platform_data *pdata;
1658         struct resource         *io;
1659         struct dw_dma           *dw;
1660         size_t                  size;
1661         void __iomem            *regs;
1662         bool                    autocfg;
1663         unsigned int            dw_params;
1664         unsigned int            nr_channels;
1665         unsigned int            max_blk_size = 0;
1666         int                     irq;
1667         int                     err;
1668         int                     i;
1669
1670         io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1671         if (!io)
1672                 return -EINVAL;
1673
1674         irq = platform_get_irq(pdev, 0);
1675         if (irq < 0)
1676                 return irq;
1677
1678         regs = devm_ioremap_resource(&pdev->dev, io);
1679         if (IS_ERR(regs))
1680                 return PTR_ERR(regs);
1681
1682         /* Apply default dma_mask if needed */
1683         if (!pdev->dev.dma_mask) {
1684                 pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
1685                 pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
1686         }
1687
1688         dw_params = dma_read_byaddr(regs, DW_PARAMS);
1689         autocfg = dw_params >> DW_PARAMS_EN & 0x1;
1690
1691         dev_dbg(&pdev->dev, "DW_PARAMS: 0x%08x\n", dw_params);
1692
1693         pdata = dev_get_platdata(&pdev->dev);
1694         if (!pdata)
1695                 pdata = dw_dma_parse_dt(pdev);
1696
1697         if (!pdata && autocfg) {
1698                 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
1699                 if (!pdata)
1700                         return -ENOMEM;
1701
1702                 /* Fill platform data with the default values */
1703                 pdata->is_private = true;
1704                 pdata->chan_allocation_order = CHAN_ALLOCATION_ASCENDING;
1705                 pdata->chan_priority = CHAN_PRIORITY_ASCENDING;
1706         } else if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS)
1707                 return -EINVAL;
1708
1709         if (autocfg)
1710                 nr_channels = (dw_params >> DW_PARAMS_NR_CHAN & 0x7) + 1;
1711         else
1712                 nr_channels = pdata->nr_channels;
1713
1714         size = sizeof(struct dw_dma) + nr_channels * sizeof(struct dw_dma_chan);
1715         dw = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
1716         if (!dw)
1717                 return -ENOMEM;
1718
1719         dw->clk = devm_clk_get(&pdev->dev, "hclk");
1720         if (IS_ERR(dw->clk))
1721                 return PTR_ERR(dw->clk);
1722         clk_prepare_enable(dw->clk);
1723
1724         dw->regs = regs;
1725
1726         /* Get hardware configuration parameters */
1727         if (autocfg) {
1728                 max_blk_size = dma_readl(dw, MAX_BLK_SIZE);
1729
1730                 dw->nr_masters = (dw_params >> DW_PARAMS_NR_MASTER & 3) + 1;
1731                 for (i = 0; i < dw->nr_masters; i++) {
1732                         dw->data_width[i] =
1733                                 (dw_params >> DW_PARAMS_DATA_WIDTH(i) & 3) + 2;
1734                 }
1735         } else {
1736                 dw->nr_masters = pdata->nr_masters;
1737                 memcpy(dw->data_width, pdata->data_width, 4);
1738         }
1739
1740         /* Calculate all channel mask before DMA setup */
1741         dw->all_chan_mask = (1 << nr_channels) - 1;
1742
1743         /* Force dma off, just in case */
1744         dw_dma_off(dw);
1745
1746         /* Disable BLOCK interrupts as well */
1747         channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1748
1749         err = devm_request_irq(&pdev->dev, irq, dw_dma_interrupt, 0,
1750                                "dw_dmac", dw);
1751         if (err)
1752                 return err;
1753
1754         platform_set_drvdata(pdev, dw);
1755
1756         /* Create a pool of consistent memory blocks for hardware descriptors */
1757         dw->desc_pool = dmam_pool_create("dw_dmac_desc_pool", &pdev->dev,
1758                                          sizeof(struct dw_desc), 4, 0);
1759         if (!dw->desc_pool) {
1760                 dev_err(&pdev->dev, "No memory for descriptors dma pool\n");
1761                 return -ENOMEM;
1762         }
1763
1764         tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
1765
1766         INIT_LIST_HEAD(&dw->dma.channels);
1767         for (i = 0; i < nr_channels; i++) {
1768                 struct dw_dma_chan      *dwc = &dw->chan[i];
1769                 int                     r = nr_channels - i - 1;
1770
1771                 dwc->chan.device = &dw->dma;
1772                 dma_cookie_init(&dwc->chan);
1773                 if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING)
1774                         list_add_tail(&dwc->chan.device_node,
1775                                         &dw->dma.channels);
1776                 else
1777                         list_add(&dwc->chan.device_node, &dw->dma.channels);
1778
1779                 /* 7 is highest priority & 0 is lowest. */
1780                 if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING)
1781                         dwc->priority = r;
1782                 else
1783                         dwc->priority = i;
1784
1785                 dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
1786                 spin_lock_init(&dwc->lock);
1787                 dwc->mask = 1 << i;
1788
1789                 INIT_LIST_HEAD(&dwc->active_list);
1790                 INIT_LIST_HEAD(&dwc->queue);
1791                 INIT_LIST_HEAD(&dwc->free_list);
1792
1793                 channel_clear_bit(dw, CH_EN, dwc->mask);
1794
1795                 dwc->direction = DMA_TRANS_NONE;
1796                 dwc->request_line = ~0;
1797
1798                 /* Hardware configuration */
1799                 if (autocfg) {
1800                         unsigned int dwc_params;
1801
1802                         dwc_params = dma_read_byaddr(regs + r * sizeof(u32),
1803                                                      DWC_PARAMS);
1804
1805                         dev_dbg(&pdev->dev, "DWC_PARAMS[%d]: 0x%08x\n", i,
1806                                             dwc_params);
1807
1808                         /* Decode maximum block size for given channel. The
1809                          * stored 4 bit value represents blocks from 0x00 for 3
1810                          * up to 0x0a for 4095. */
1811                         dwc->block_size =
1812                                 (4 << ((max_blk_size >> 4 * i) & 0xf)) - 1;
1813                         dwc->nollp =
1814                                 (dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0;
1815                 } else {
1816                         dwc->block_size = pdata->block_size;
1817
1818                         /* Check if channel supports multi block transfer */
1819                         channel_writel(dwc, LLP, 0xfffffffc);
1820                         dwc->nollp =
1821                                 (channel_readl(dwc, LLP) & 0xfffffffc) == 0;
1822                         channel_writel(dwc, LLP, 0);
1823                 }
1824         }
1825
1826         /* Clear all interrupts on all channels. */
1827         dma_writel(dw, CLEAR.XFER, dw->all_chan_mask);
1828         dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask);
1829         dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask);
1830         dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask);
1831         dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask);
1832
1833         dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
1834         dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
1835         if (pdata->is_private)
1836                 dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask);
1837         dw->dma.dev = &pdev->dev;
1838         dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
1839         dw->dma.device_free_chan_resources = dwc_free_chan_resources;
1840
1841         dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
1842
1843         dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
1844         dw->dma.device_control = dwc_control;
1845
1846         dw->dma.device_tx_status = dwc_tx_status;
1847         dw->dma.device_issue_pending = dwc_issue_pending;
1848
1849         dma_writel(dw, CFG, DW_CFG_DMA_EN);
1850
1851         dev_info(&pdev->dev, "DesignWare DMA Controller, %d channels\n",
1852                  nr_channels);
1853
1854         dma_async_device_register(&dw->dma);
1855
1856         if (pdev->dev.of_node) {
1857                 err = of_dma_controller_register(pdev->dev.of_node,
1858                                                  dw_dma_of_xlate, dw);
1859                 if (err)
1860                         dev_err(&pdev->dev,
1861                                 "could not register of_dma_controller\n");
1862         }
1863
1864         if (ACPI_HANDLE(&pdev->dev))
1865                 dw_dma_acpi_controller_register(dw);
1866
1867         return 0;
1868 }
1869
1870 static int dw_remove(struct platform_device *pdev)
1871 {
1872         struct dw_dma           *dw = platform_get_drvdata(pdev);
1873         struct dw_dma_chan      *dwc, *_dwc;
1874
1875         if (pdev->dev.of_node)
1876                 of_dma_controller_free(pdev->dev.of_node);
1877         dw_dma_off(dw);
1878         dma_async_device_unregister(&dw->dma);
1879
1880         tasklet_kill(&dw->tasklet);
1881
1882         list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,
1883                         chan.device_node) {
1884                 list_del(&dwc->chan.device_node);
1885                 channel_clear_bit(dw, CH_EN, dwc->mask);
1886         }
1887
1888         return 0;
1889 }
1890
1891 static void dw_shutdown(struct platform_device *pdev)
1892 {
1893         struct dw_dma   *dw = platform_get_drvdata(pdev);
1894
1895         dw_dma_off(dw);
1896         clk_disable_unprepare(dw->clk);
1897 }
1898
1899 static int dw_suspend_noirq(struct device *dev)
1900 {
1901         struct platform_device *pdev = to_platform_device(dev);
1902         struct dw_dma   *dw = platform_get_drvdata(pdev);
1903
1904         dw_dma_off(dw);
1905         clk_disable_unprepare(dw->clk);
1906
1907         return 0;
1908 }
1909
1910 static int dw_resume_noirq(struct device *dev)
1911 {
1912         struct platform_device *pdev = to_platform_device(dev);
1913         struct dw_dma   *dw = platform_get_drvdata(pdev);
1914
1915         clk_prepare_enable(dw->clk);
1916         dma_writel(dw, CFG, DW_CFG_DMA_EN);
1917
1918         return 0;
1919 }
1920
1921 static const struct dev_pm_ops dw_dev_pm_ops = {
1922         .suspend_noirq = dw_suspend_noirq,
1923         .resume_noirq = dw_resume_noirq,
1924         .freeze_noirq = dw_suspend_noirq,
1925         .thaw_noirq = dw_resume_noirq,
1926         .restore_noirq = dw_resume_noirq,
1927         .poweroff_noirq = dw_suspend_noirq,
1928 };
1929
1930 #ifdef CONFIG_OF
1931 static const struct of_device_id dw_dma_of_id_table[] = {
1932         { .compatible = "snps,dma-spear1340" },
1933         {}
1934 };
1935 MODULE_DEVICE_TABLE(of, dw_dma_of_id_table);
1936 #endif
1937
1938 #ifdef CONFIG_ACPI
1939 static const struct acpi_device_id dw_dma_acpi_id_table[] = {
1940         { "INTL9C60", 0 },
1941         { }
1942 };
1943 #endif
1944
1945 static struct platform_driver dw_driver = {
1946         .probe          = dw_probe,
1947         .remove         = dw_remove,
1948         .shutdown       = dw_shutdown,
1949         .driver = {
1950                 .name   = "dw_dmac",
1951                 .pm     = &dw_dev_pm_ops,
1952                 .of_match_table = of_match_ptr(dw_dma_of_id_table),
1953                 .acpi_match_table = ACPI_PTR(dw_dma_acpi_id_table),
1954         },
1955 };
1956
1957 static int __init dw_init(void)
1958 {
1959         return platform_driver_register(&dw_driver);
1960 }
1961 subsys_initcall(dw_init);
1962
1963 static void __exit dw_exit(void)
1964 {
1965         platform_driver_unregister(&dw_driver);
1966 }
1967 module_exit(dw_exit);
1968
1969 MODULE_LICENSE("GPL v2");
1970 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller driver");
1971 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
1972 MODULE_AUTHOR("Viresh Kumar <viresh.linux@gmail.com>");