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