drivers/dma/dw/core.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  * Copyright (C) 2013 Intel Corporation
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/bitops.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/mm.h>
  23 #include <linux/module.h>
  24 #include <linux/slab.h>
  25 #include <linux/pm_runtime.h>
  26
  27 #include "../dmaengine.h"
  28 #include "internal.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 been tested with the Atmel AT32AP7000, which does not
  37  * support descriptor writeback.
  38  */
  39
  40 #define DWC_DEFAULT_CTLLO(_chan) ({                             \
  41                 struct dw_dma_chan *_dwc = to_dw_dma_chan(_chan);       \
  42                 struct dma_slave_config *_sconfig = &_dwc->dma_sconfig; \
  43                 bool _is_slave = is_slave_direction(_dwc->direction);   \
  44                 u8 _smsize = _is_slave ? _sconfig->src_maxburst :       \
  45                         DW_DMA_MSIZE_16;                        \
  46                 u8 _dmsize = _is_slave ? _sconfig->dst_maxburst :       \
  47                         DW_DMA_MSIZE_16;                        \
  48                                                                 \
  49                 (DWC_CTLL_DST_MSIZE(_dmsize)                    \
  50                  | DWC_CTLL_SRC_MSIZE(_smsize)                  \
  51                  | DWC_CTLL_LLP_D_EN                            \
  52                  | DWC_CTLL_LLP_S_EN                            \
  53                  | DWC_CTLL_DMS(_dwc->dst_master)               \
  54                  | DWC_CTLL_SMS(_dwc->src_master));             \
  55         })
  56
  57 /*
  58  * Number of descriptors to allocate for each channel. This should be
  59  * made configurable somehow; preferably, the clients (at least the
  60  * ones using slave transfers) should be able to give us a hint.
  61  */
  62 #define NR_DESCS_PER_CHANNEL    64
  63
  64 /* The set of bus widths supported by the DMA controller */
  65 #define DW_DMA_BUSWIDTHS                          \
  66         BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED)       | \
  67         BIT(DMA_SLAVE_BUSWIDTH_1_BYTE)          | \
  68         BIT(DMA_SLAVE_BUSWIDTH_2_BYTES)         | \
  69         BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)
  70
  71 /*----------------------------------------------------------------------*/
  72
  73 static struct device *chan2dev(struct dma_chan *chan)
  74 {
  75         return &chan->dev->device;
  76 }
  77
  78 static struct dw_desc *dwc_first_active(struct dw_dma_chan *dwc)
  79 {
  80         return to_dw_desc(dwc->active_list.next);
  81 }
  82
  83 static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc)
  84 {
  85         struct dw_desc *desc, *_desc;
  86         struct dw_desc *ret = NULL;
  87         unsigned int i = 0;
  88         unsigned long flags;
  89
  90         spin_lock_irqsave(&dwc->lock, flags);
  91         list_for_each_entry_safe(desc, _desc, &dwc->free_list, desc_node) {
  92                 i++;
  93                 if (async_tx_test_ack(&desc->txd)) {
  94                         list_del(&desc->desc_node);
  95                         ret = desc;
  96                         break;
  97                 }
  98                 dev_dbg(chan2dev(&dwc->chan), "desc %p not ACKed\n", desc);
  99         }
 100         spin_unlock_irqrestore(&dwc->lock, flags);
 101
 102         dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i);
 103
 104         return ret;
 105 }
 106
 107 /*
 108  * Move a descriptor, including any children, to the free list.
 109  * `desc' must not be on any lists.
 110  */
 111 static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
 112 {
 113         unsigned long flags;
 114
 115         if (desc) {
 116                 struct dw_desc *child;
 117
 118                 spin_lock_irqsave(&dwc->lock, flags);
 119                 list_for_each_entry(child, &desc->tx_list, desc_node)
 120                         dev_vdbg(chan2dev(&dwc->chan),
 121                                         "moving child desc %p to freelist\n",
 122                                         child);
 123                 list_splice_init(&desc->tx_list, &dwc->free_list);
 124                 dev_vdbg(chan2dev(&dwc->chan), "moving desc %p to freelist\n", desc);
 125                 list_add(&desc->desc_node, &dwc->free_list);
 126                 spin_unlock_irqrestore(&dwc->lock, flags);
 127         }
 128 }
 129
 130 static void dwc_initialize(struct dw_dma_chan *dwc)
 131 {
 132         struct dw_dma *dw = to_dw_dma(dwc->chan.device);
 133         u32 cfghi = DWC_CFGH_FIFO_MODE;
 134         u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
 135
 136         if (dwc->initialized == true)
 137                 return;
 138
 139         cfghi |= DWC_CFGH_DST_PER(dwc->dst_id);
 140         cfghi |= DWC_CFGH_SRC_PER(dwc->src_id);
 141
 142         channel_writel(dwc, CFG_LO, cfglo);
 143         channel_writel(dwc, CFG_HI, cfghi);
 144
 145         /* Enable interrupts */
 146         channel_set_bit(dw, MASK.XFER, dwc->mask);
 147         channel_set_bit(dw, MASK.ERROR, dwc->mask);
 148
 149         dwc->initialized = true;
 150 }
 151
 152 /*----------------------------------------------------------------------*/
 153
 154 static inline unsigned int dwc_fast_ffs(unsigned long long v)
 155 {
 156         /*
 157          * We can be a lot more clever here, but this should take care
 158          * of the most common optimization.
 159          */
 160         if (!(v & 7))
 161                 return 3;
 162         else if (!(v & 3))
 163                 return 2;
 164         else if (!(v & 1))
 165                 return 1;
 166         return 0;
 167 }
 168
 169 static inline void dwc_dump_chan_regs(struct dw_dma_chan *dwc)
 170 {
 171         dev_err(chan2dev(&dwc->chan),
 172                 "  SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
 173                 channel_readl(dwc, SAR),
 174                 channel_readl(dwc, DAR),
 175                 channel_readl(dwc, LLP),
 176                 channel_readl(dwc, CTL_HI),
 177                 channel_readl(dwc, CTL_LO));
 178 }
 179
 180 static inline void dwc_chan_disable(struct dw_dma *dw, struct dw_dma_chan *dwc)
 181 {
 182         channel_clear_bit(dw, CH_EN, dwc->mask);
 183         while (dma_readl(dw, CH_EN) & dwc->mask)
 184                 cpu_relax();
 185 }
 186
 187 /*----------------------------------------------------------------------*/
 188
 189 /* Perform single block transfer */
 190 static inline void dwc_do_single_block(struct dw_dma_chan *dwc,
 191                                        struct dw_desc *desc)
 192 {
 193         struct dw_dma   *dw = to_dw_dma(dwc->chan.device);
 194         u32             ctllo;
 195
 196         /*
 197          * Software emulation of LLP mode relies on interrupts to continue
 198          * multi block transfer.
 199          */
 200         ctllo = desc->lli.ctllo | DWC_CTLL_INT_EN;
 201
 202         channel_writel(dwc, SAR, desc->lli.sar);
 203         channel_writel(dwc, DAR, desc->lli.dar);
 204         channel_writel(dwc, CTL_LO, ctllo);
 205         channel_writel(dwc, CTL_HI, desc->lli.ctlhi);
 206         channel_set_bit(dw, CH_EN, dwc->mask);
 207
 208         /* Move pointer to next descriptor */
 209         dwc->tx_node_active = dwc->tx_node_active->next;
 210 }
 211
 212 /* Called with dwc->lock held and bh disabled */
 213 static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
 214 {
 215         struct dw_dma   *dw = to_dw_dma(dwc->chan.device);
 216         unsigned long   was_soft_llp;
 217
 218         /* ASSERT:  channel is idle */
 219         if (dma_readl(dw, CH_EN) & dwc->mask) {
 220                 dev_err(chan2dev(&dwc->chan),
 221                         "%s: BUG: Attempted to start non-idle channel\n",
 222                         __func__);
 223                 dwc_dump_chan_regs(dwc);
 224
 225                 /* The tasklet will hopefully advance the queue... */
 226                 return;
 227         }
 228
 229         if (dwc->nollp) {
 230                 was_soft_llp = test_and_set_bit(DW_DMA_IS_SOFT_LLP,
 231                                                 &dwc->flags);
 232                 if (was_soft_llp) {
 233                         dev_err(chan2dev(&dwc->chan),
 234                                 "BUG: Attempted to start new LLP transfer inside ongoing one\n");
 235                         return;
 236                 }
 237
 238                 dwc_initialize(dwc);
 239
 240                 dwc->residue = first->total_len;
 241                 dwc->tx_node_active = &first->tx_list;
 242
 243                 /* Submit first block */
 244                 dwc_do_single_block(dwc, first);
 245
 246                 return;
 247         }
 248
 249         dwc_initialize(dwc);
 250
 251         channel_writel(dwc, LLP, first->txd.phys);
 252         channel_writel(dwc, CTL_LO,
 253                         DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
 254         channel_writel(dwc, CTL_HI, 0);
 255         channel_set_bit(dw, CH_EN, dwc->mask);
 256 }
 257
 258 static void dwc_dostart_first_queued(struct dw_dma_chan *dwc)
 259 {
 260         struct dw_desc *desc;
 261
 262         if (list_empty(&dwc->queue))
 263                 return;
 264
 265         list_move(dwc->queue.next, &dwc->active_list);
 266         desc = dwc_first_active(dwc);
 267         dev_vdbg(chan2dev(&dwc->chan), "%s: started %u\n", __func__, desc->txd.cookie);
 268         dwc_dostart(dwc, desc);
 269 }
 270
 271 /*----------------------------------------------------------------------*/
 272
 273 static void
 274 dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc,
 275                 bool callback_required)
 276 {
 277         dma_async_tx_callback           callback = NULL;
 278         void                            *param = NULL;
 279         struct dma_async_tx_descriptor  *txd = &desc->txd;
 280         struct dw_desc                  *child;
 281         unsigned long                   flags;
 282
 283         dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
 284
 285         spin_lock_irqsave(&dwc->lock, flags);
 286         dma_cookie_complete(txd);
 287         if (callback_required) {
 288                 callback = txd->callback;
 289                 param = txd->callback_param;
 290         }
 291
 292         /* async_tx_ack */
 293         list_for_each_entry(child, &desc->tx_list, desc_node)
 294                 async_tx_ack(&child->txd);
 295         async_tx_ack(&desc->txd);
 296
 297         list_splice_init(&desc->tx_list, &dwc->free_list);
 298         list_move(&desc->desc_node, &dwc->free_list);
 299
 300         dma_descriptor_unmap(txd);
 301         spin_unlock_irqrestore(&dwc->lock, flags);
 302
 303         if (callback)
 304                 callback(param);
 305 }
 306
 307 static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
 308 {
 309         struct dw_desc *desc, *_desc;
 310         LIST_HEAD(list);
 311         unsigned long flags;
 312
 313         spin_lock_irqsave(&dwc->lock, flags);
 314         if (dma_readl(dw, CH_EN) & dwc->mask) {
 315                 dev_err(chan2dev(&dwc->chan),
 316                         "BUG: XFER bit set, but channel not idle!\n");
 317
 318                 /* Try to continue after resetting the channel... */
 319                 dwc_chan_disable(dw, dwc);
 320         }
 321
 322         /*
 323          * Submit queued descriptors ASAP, i.e. before we go through
 324          * the completed ones.
 325          */
 326         list_splice_init(&dwc->active_list, &list);
 327         dwc_dostart_first_queued(dwc);
 328
 329         spin_unlock_irqrestore(&dwc->lock, flags);
 330
 331         list_for_each_entry_safe(desc, _desc, &list, desc_node)
 332                 dwc_descriptor_complete(dwc, desc, true);
 333 }
 334
 335 /* Returns how many bytes were already received from source */
 336 static inline u32 dwc_get_sent(struct dw_dma_chan *dwc)
 337 {
 338         u32 ctlhi = channel_readl(dwc, CTL_HI);
 339         u32 ctllo = channel_readl(dwc, CTL_LO);
 340
 341         return (ctlhi & DWC_CTLH_BLOCK_TS_MASK) * (1 << (ctllo >> 4 & 7));
 342 }
 343
 344 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
 345 {
 346         dma_addr_t llp;
 347         struct dw_desc *desc, *_desc;
 348         struct dw_desc *child;
 349         u32 status_xfer;
 350         unsigned long flags;
 351
 352         spin_lock_irqsave(&dwc->lock, flags);
 353         llp = channel_readl(dwc, LLP);
 354         status_xfer = dma_readl(dw, RAW.XFER);
 355
 356         if (status_xfer & dwc->mask) {
 357                 /* Everything we've submitted is done */
 358                 dma_writel(dw, CLEAR.XFER, dwc->mask);
 359
 360                 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
 361                         struct list_head *head, *active = dwc->tx_node_active;
 362
 363                         /*
 364                          * We are inside first active descriptor.
 365                          * Otherwise something is really wrong.
 366                          */
 367                         desc = dwc_first_active(dwc);
 368
 369                         head = &desc->tx_list;
 370                         if (active != head) {
 371                                 /* Update desc to reflect last sent one */
 372                                 if (active != head->next)
 373                                         desc = to_dw_desc(active->prev);
 374
 375                                 dwc->residue -= desc->len;
 376
 377                                 child = to_dw_desc(active);
 378
 379                                 /* Submit next block */
 380                                 dwc_do_single_block(dwc, child);
 381
 382                                 spin_unlock_irqrestore(&dwc->lock, flags);
 383                                 return;
 384                         }
 385
 386                         /* We are done here */
 387                         clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
 388                 }
 389
 390                 dwc->residue = 0;
 391
 392                 spin_unlock_irqrestore(&dwc->lock, flags);
 393
 394                 dwc_complete_all(dw, dwc);
 395                 return;
 396         }
 397
 398         if (list_empty(&dwc->active_list)) {
 399                 dwc->residue = 0;
 400                 spin_unlock_irqrestore(&dwc->lock, flags);
 401                 return;
 402         }
 403
 404         if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
 405                 dev_vdbg(chan2dev(&dwc->chan), "%s: soft LLP mode\n", __func__);
 406                 spin_unlock_irqrestore(&dwc->lock, flags);
 407                 return;
 408         }
 409
 410         dev_vdbg(chan2dev(&dwc->chan), "%s: llp=%pad\n", __func__, &llp);
 411
 412         list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
 413                 /* Initial residue value */
 414                 dwc->residue = desc->total_len;
 415
 416                 /* Check first descriptors addr */
 417                 if (desc->txd.phys == llp) {
 418                         spin_unlock_irqrestore(&dwc->lock, flags);
 419                         return;
 420                 }
 421
 422                 /* Check first descriptors llp */
 423                 if (desc->lli.llp == llp) {
 424                         /* This one is currently in progress */
 425                         dwc->residue -= dwc_get_sent(dwc);
 426                         spin_unlock_irqrestore(&dwc->lock, flags);
 427                         return;
 428                 }
 429
 430                 dwc->residue -= desc->len;
 431                 list_for_each_entry(child, &desc->tx_list, desc_node) {
 432                         if (child->lli.llp == llp) {
 433                                 /* Currently in progress */
 434                                 dwc->residue -= dwc_get_sent(dwc);
 435                                 spin_unlock_irqrestore(&dwc->lock, flags);
 436                                 return;
 437                         }
 438                         dwc->residue -= child->len;
 439                 }
 440
 441                 /*
 442                  * No descriptors so far seem to be in progress, i.e.
 443                  * this one must be done.
 444                  */
 445                 spin_unlock_irqrestore(&dwc->lock, flags);
 446                 dwc_descriptor_complete(dwc, desc, true);
 447                 spin_lock_irqsave(&dwc->lock, flags);
 448         }
 449
 450         dev_err(chan2dev(&dwc->chan),
 451                 "BUG: All descriptors done, but channel not idle!\n");
 452
 453         /* Try to continue after resetting the channel... */
 454         dwc_chan_disable(dw, dwc);
 455
 456         dwc_dostart_first_queued(dwc);
 457         spin_unlock_irqrestore(&dwc->lock, flags);
 458 }
 459
 460 static inline void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli)
 461 {
 462         dev_crit(chan2dev(&dwc->chan), "  desc: s0x%x d0x%x l0x%x c0x%x:%x\n",
 463                  lli->sar, lli->dar, lli->llp, lli->ctlhi, lli->ctllo);
 464 }
 465
 466 static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
 467 {
 468         struct dw_desc *bad_desc;
 469         struct dw_desc *child;
 470         unsigned long flags;
 471
 472         dwc_scan_descriptors(dw, dwc);
 473
 474         spin_lock_irqsave(&dwc->lock, flags);
 475
 476         /*
 477          * The descriptor currently at the head of the active list is
 478          * borked. Since we don't have any way to report errors, we'll
 479          * just have to scream loudly and try to carry on.
 480          */
 481         bad_desc = dwc_first_active(dwc);
 482         list_del_init(&bad_desc->desc_node);
 483         list_move(dwc->queue.next, dwc->active_list.prev);
 484
 485         /* Clear the error flag and try to restart the controller */
 486         dma_writel(dw, CLEAR.ERROR, dwc->mask);
 487         if (!list_empty(&dwc->active_list))
 488                 dwc_dostart(dwc, dwc_first_active(dwc));
 489
 490         /*
 491          * WARN may seem harsh, but since this only happens
 492          * when someone submits a bad physical address in a
 493          * descriptor, we should consider ourselves lucky that the
 494          * controller flagged an error instead of scribbling over
 495          * random memory locations.
 496          */
 497         dev_WARN(chan2dev(&dwc->chan), "Bad descriptor submitted for DMA!\n"
 498                                        "  cookie: %d\n", bad_desc->txd.cookie);
 499         dwc_dump_lli(dwc, &bad_desc->lli);
 500         list_for_each_entry(child, &bad_desc->tx_list, desc_node)
 501                 dwc_dump_lli(dwc, &child->lli);
 502
 503         spin_unlock_irqrestore(&dwc->lock, flags);
 504
 505         /* Pretend the descriptor completed successfully */
 506         dwc_descriptor_complete(dwc, bad_desc, true);
 507 }
 508
 509 /* --------------------- Cyclic DMA API extensions -------------------- */
 510
 511 dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan)
 512 {
 513         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 514         return channel_readl(dwc, SAR);
 515 }
 516 EXPORT_SYMBOL(dw_dma_get_src_addr);
 517
 518 dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan)
 519 {
 520         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 521         return channel_readl(dwc, DAR);
 522 }
 523 EXPORT_SYMBOL(dw_dma_get_dst_addr);
 524
 525 /* Called with dwc->lock held and all DMAC interrupts disabled */
 526 static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
 527                 u32 status_block, u32 status_err, u32 status_xfer)
 528 {
 529         unsigned long flags;
 530
 531         if (status_block & dwc->mask) {
 532                 void (*callback)(void *param);
 533                 void *callback_param;
 534
 535                 dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp 0x%08x\n",
 536                                 channel_readl(dwc, LLP));
 537                 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
 538
 539                 callback = dwc->cdesc->period_callback;
 540                 callback_param = dwc->cdesc->period_callback_param;
 541
 542                 if (callback)
 543                         callback(callback_param);
 544         }
 545
 546         /*
 547          * Error and transfer complete are highly unlikely, and will most
 548          * likely be due to a configuration error by the user.
 549          */
 550         if (unlikely(status_err & dwc->mask) ||
 551                         unlikely(status_xfer & dwc->mask)) {
 552                 int i;
 553
 554                 dev_err(chan2dev(&dwc->chan),
 555                         "cyclic DMA unexpected %s interrupt, stopping DMA transfer\n",
 556                         status_xfer ? "xfer" : "error");
 557
 558                 spin_lock_irqsave(&dwc->lock, flags);
 559
 560                 dwc_dump_chan_regs(dwc);
 561
 562                 dwc_chan_disable(dw, dwc);
 563
 564                 /* Make sure DMA does not restart by loading a new list */
 565                 channel_writel(dwc, LLP, 0);
 566                 channel_writel(dwc, CTL_LO, 0);
 567                 channel_writel(dwc, CTL_HI, 0);
 568
 569                 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
 570                 dma_writel(dw, CLEAR.ERROR, dwc->mask);
 571                 dma_writel(dw, CLEAR.XFER, dwc->mask);
 572
 573                 for (i = 0; i < dwc->cdesc->periods; i++)
 574                         dwc_dump_lli(dwc, &dwc->cdesc->desc[i]->lli);
 575
 576                 spin_unlock_irqrestore(&dwc->lock, flags);
 577         }
 578
 579         /* Re-enable interrupts */
 580         channel_set_bit(dw, MASK.BLOCK, dwc->mask);
 581 }
 582
 583 /* ------------------------------------------------------------------------- */
 584
 585 static void dw_dma_tasklet(unsigned long data)
 586 {
 587         struct dw_dma *dw = (struct dw_dma *)data;
 588         struct dw_dma_chan *dwc;
 589         u32 status_block;
 590         u32 status_xfer;
 591         u32 status_err;
 592         int i;
 593
 594         status_block = dma_readl(dw, RAW.BLOCK);
 595         status_xfer = dma_readl(dw, RAW.XFER);
 596         status_err = dma_readl(dw, RAW.ERROR);
 597
 598         dev_vdbg(dw->dma.dev, "%s: status_err=%x\n", __func__, status_err);
 599
 600         for (i = 0; i < dw->dma.chancnt; i++) {
 601                 dwc = &dw->chan[i];
 602                 if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
 603                         dwc_handle_cyclic(dw, dwc, status_block, status_err,
 604                                         status_xfer);
 605                 else if (status_err & (1 << i))
 606                         dwc_handle_error(dw, dwc);
 607                 else if (status_xfer & (1 << i))
 608                         dwc_scan_descriptors(dw, dwc);
 609         }
 610
 611         /* Re-enable interrupts */
 612         channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
 613         channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask);
 614 }
 615
 616 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
 617 {
 618         struct dw_dma *dw = dev_id;
 619         u32 status;
 620
 621         /* Check if we have any interrupt from the DMAC which is not in use */
 622         if (!dw->in_use)
 623                 return IRQ_NONE;
 624
 625         status = dma_readl(dw, STATUS_INT);
 626         dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__, status);
 627
 628         /* Check if we have any interrupt from the DMAC */
 629         if (!status)
 630                 return IRQ_NONE;
 631
 632         /*
 633          * Just disable the interrupts. We'll turn them back on in the
 634          * softirq handler.
 635          */
 636         channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
 637         channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
 638         channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
 639
 640         status = dma_readl(dw, STATUS_INT);
 641         if (status) {
 642                 dev_err(dw->dma.dev,
 643                         "BUG: Unexpected interrupts pending: 0x%x\n",
 644                         status);
 645
 646                 /* Try to recover */
 647                 channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1);
 648                 channel_clear_bit(dw, MASK.BLOCK, (1 << 8) - 1);
 649                 channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1);
 650                 channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1);
 651                 channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1);
 652         }
 653
 654         tasklet_schedule(&dw->tasklet);
 655
 656         return IRQ_HANDLED;
 657 }
 658
 659 /*----------------------------------------------------------------------*/
 660
 661 static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
 662 {
 663         struct dw_desc          *desc = txd_to_dw_desc(tx);
 664         struct dw_dma_chan      *dwc = to_dw_dma_chan(tx->chan);
 665         dma_cookie_t            cookie;
 666         unsigned long           flags;
 667
 668         spin_lock_irqsave(&dwc->lock, flags);
 669         cookie = dma_cookie_assign(tx);
 670
 671         /*
 672          * REVISIT: We should attempt to chain as many descriptors as
 673          * possible, perhaps even appending to those already submitted
 674          * for DMA. But this is hard to do in a race-free manner.
 675          */
 676
 677         dev_vdbg(chan2dev(tx->chan), "%s: queued %u\n", __func__, desc->txd.cookie);
 678         list_add_tail(&desc->desc_node, &dwc->queue);
 679
 680         spin_unlock_irqrestore(&dwc->lock, flags);
 681
 682         return cookie;
 683 }
 684
 685 static struct dma_async_tx_descriptor *
 686 dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 687                 size_t len, unsigned long flags)
 688 {
 689         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 690         struct dw_dma           *dw = to_dw_dma(chan->device);
 691         struct dw_desc          *desc;
 692         struct dw_desc          *first;
 693         struct dw_desc          *prev;
 694         size_t                  xfer_count;
 695         size_t                  offset;
 696         unsigned int            src_width;
 697         unsigned int            dst_width;
 698         unsigned int            data_width;
 699         u32                     ctllo;
 700
 701         dev_vdbg(chan2dev(chan),
 702                         "%s: d%pad s%pad l0x%zx f0x%lx\n", __func__,
 703                         &dest, &src, len, flags);
 704
 705         if (unlikely(!len)) {
 706                 dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__);
 707                 return NULL;
 708         }
 709
 710         dwc->direction = DMA_MEM_TO_MEM;
 711
 712         data_width = min_t(unsigned int, dw->data_width[dwc->src_master],
 713                            dw->data_width[dwc->dst_master]);
 714
 715         src_width = dst_width = min_t(unsigned int, data_width,
 716                                       dwc_fast_ffs(src | dest | len));
 717
 718         ctllo = DWC_DEFAULT_CTLLO(chan)
 719                         | DWC_CTLL_DST_WIDTH(dst_width)
 720                         | DWC_CTLL_SRC_WIDTH(src_width)
 721                         | DWC_CTLL_DST_INC
 722                         | DWC_CTLL_SRC_INC
 723                         | DWC_CTLL_FC_M2M;
 724         prev = first = NULL;
 725
 726         for (offset = 0; offset < len; offset += xfer_count << src_width) {
 727                 xfer_count = min_t(size_t, (len - offset) >> src_width,
 728                                            dwc->block_size);
 729
 730                 desc = dwc_desc_get(dwc);
 731                 if (!desc)
 732                         goto err_desc_get;
 733
 734                 desc->lli.sar = src + offset;
 735                 desc->lli.dar = dest + offset;
 736                 desc->lli.ctllo = ctllo;
 737                 desc->lli.ctlhi = xfer_count;
 738                 desc->len = xfer_count << src_width;
 739
 740                 if (!first) {
 741                         first = desc;
 742                 } else {
 743                         prev->lli.llp = desc->txd.phys;
 744                         list_add_tail(&desc->desc_node,
 745                                         &first->tx_list);
 746                 }
 747                 prev = desc;
 748         }
 749
 750         if (flags & DMA_PREP_INTERRUPT)
 751                 /* Trigger interrupt after last block */
 752                 prev->lli.ctllo |= DWC_CTLL_INT_EN;
 753
 754         prev->lli.llp = 0;
 755         first->txd.flags = flags;
 756         first->total_len = len;
 757
 758         return &first->txd;
 759
 760 err_desc_get:
 761         dwc_desc_put(dwc, first);
 762         return NULL;
 763 }
 764
 765 static struct dma_async_tx_descriptor *
 766 dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 767                 unsigned int sg_len, enum dma_transfer_direction direction,
 768                 unsigned long flags, void *context)
 769 {
 770         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 771         struct dw_dma           *dw = to_dw_dma(chan->device);
 772         struct dma_slave_config *sconfig = &dwc->dma_sconfig;
 773         struct dw_desc          *prev;
 774         struct dw_desc          *first;
 775         u32                     ctllo;
 776         dma_addr_t              reg;
 777         unsigned int            reg_width;
 778         unsigned int            mem_width;
 779         unsigned int            data_width;
 780         unsigned int            i;
 781         struct scatterlist      *sg;
 782         size_t                  total_len = 0;
 783
 784         dev_vdbg(chan2dev(chan), "%s\n", __func__);
 785
 786         if (unlikely(!is_slave_direction(direction) || !sg_len))
 787                 return NULL;
 788
 789         dwc->direction = direction;
 790
 791         prev = first = NULL;
 792
 793         switch (direction) {
 794         case DMA_MEM_TO_DEV:
 795                 reg_width = __ffs(sconfig->dst_addr_width);
 796                 reg = sconfig->dst_addr;
 797                 ctllo = (DWC_DEFAULT_CTLLO(chan)
 798                                 | DWC_CTLL_DST_WIDTH(reg_width)
 799                                 | DWC_CTLL_DST_FIX
 800                                 | DWC_CTLL_SRC_INC);
 801
 802                 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
 803                         DWC_CTLL_FC(DW_DMA_FC_D_M2P);
 804
 805                 data_width = dw->data_width[dwc->src_master];
 806
 807                 for_each_sg(sgl, sg, sg_len, i) {
 808                         struct dw_desc  *desc;
 809                         u32             len, dlen, mem;
 810
 811                         mem = sg_dma_address(sg);
 812                         len = sg_dma_len(sg);
 813
 814                         mem_width = min_t(unsigned int,
 815                                           data_width, dwc_fast_ffs(mem | len));
 816
 817 slave_sg_todev_fill_desc:
 818                         desc = dwc_desc_get(dwc);
 819                         if (!desc)
 820                                 goto err_desc_get;
 821
 822                         desc->lli.sar = mem;
 823                         desc->lli.dar = reg;
 824                         desc->lli.ctllo = ctllo | DWC_CTLL_SRC_WIDTH(mem_width);
 825                         if ((len >> mem_width) > dwc->block_size) {
 826                                 dlen = dwc->block_size << mem_width;
 827                                 mem += dlen;
 828                                 len -= dlen;
 829                         } else {
 830                                 dlen = len;
 831                                 len = 0;
 832                         }
 833
 834                         desc->lli.ctlhi = dlen >> mem_width;
 835                         desc->len = dlen;
 836
 837                         if (!first) {
 838                                 first = desc;
 839                         } else {
 840                                 prev->lli.llp = desc->txd.phys;
 841                                 list_add_tail(&desc->desc_node,
 842                                                 &first->tx_list);
 843                         }
 844                         prev = desc;
 845                         total_len += dlen;
 846
 847                         if (len)
 848                                 goto slave_sg_todev_fill_desc;
 849                 }
 850                 break;
 851         case DMA_DEV_TO_MEM:
 852                 reg_width = __ffs(sconfig->src_addr_width);
 853                 reg = sconfig->src_addr;
 854                 ctllo = (DWC_DEFAULT_CTLLO(chan)
 855                                 | DWC_CTLL_SRC_WIDTH(reg_width)
 856                                 | DWC_CTLL_DST_INC
 857                                 | DWC_CTLL_SRC_FIX);
 858
 859                 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
 860                         DWC_CTLL_FC(DW_DMA_FC_D_P2M);
 861
 862                 data_width = dw->data_width[dwc->dst_master];
 863
 864                 for_each_sg(sgl, sg, sg_len, i) {
 865                         struct dw_desc  *desc;
 866                         u32             len, dlen, mem;
 867
 868                         mem = sg_dma_address(sg);
 869                         len = sg_dma_len(sg);
 870
 871                         mem_width = min_t(unsigned int,
 872                                           data_width, dwc_fast_ffs(mem | len));
 873
 874 slave_sg_fromdev_fill_desc:
 875                         desc = dwc_desc_get(dwc);
 876                         if (!desc)
 877                                 goto err_desc_get;
 878
 879                         desc->lli.sar = reg;
 880                         desc->lli.dar = mem;
 881                         desc->lli.ctllo = ctllo | DWC_CTLL_DST_WIDTH(mem_width);
 882                         if ((len >> reg_width) > dwc->block_size) {
 883                                 dlen = dwc->block_size << reg_width;
 884                                 mem += dlen;
 885                                 len -= dlen;
 886                         } else {
 887                                 dlen = len;
 888                                 len = 0;
 889                         }
 890                         desc->lli.ctlhi = dlen >> reg_width;
 891                         desc->len = dlen;
 892
 893                         if (!first) {
 894                                 first = desc;
 895                         } else {
 896                                 prev->lli.llp = desc->txd.phys;
 897                                 list_add_tail(&desc->desc_node,
 898                                                 &first->tx_list);
 899                         }
 900                         prev = desc;
 901                         total_len += dlen;
 902
 903                         if (len)
 904                                 goto slave_sg_fromdev_fill_desc;
 905                 }
 906                 break;
 907         default:
 908                 return NULL;
 909         }
 910
 911         if (flags & DMA_PREP_INTERRUPT)
 912                 /* Trigger interrupt after last block */
 913                 prev->lli.ctllo |= DWC_CTLL_INT_EN;
 914
 915         prev->lli.llp = 0;
 916         first->total_len = total_len;
 917
 918         return &first->txd;
 919
 920 err_desc_get:
 921         dev_err(chan2dev(chan),
 922                 "not enough descriptors available. Direction %d\n", direction);
 923         dwc_desc_put(dwc, first);
 924         return NULL;
 925 }
 926
 927 bool dw_dma_filter(struct dma_chan *chan, void *param)
 928 {
 929         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 930         struct dw_dma_slave *dws = param;
 931
 932         if (dws->dma_dev != chan->device->dev)
 933                 return false;
 934
 935         /* We have to copy data since dws can be temporary storage */
 936
 937         dwc->src_id = dws->src_id;
 938         dwc->dst_id = dws->dst_id;
 939
 940         dwc->src_master = dws->src_master;
 941         dwc->dst_master = dws->dst_master;
 942
 943         return true;
 944 }
 945 EXPORT_SYMBOL_GPL(dw_dma_filter);
 946
 947 /*
 948  * Fix sconfig's burst size according to dw_dmac. We need to convert them as:
 949  * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
 950  *
 951  * NOTE: burst size 2 is not supported by controller.
 952  *
 953  * This can be done by finding least significant bit set: n & (n - 1)
 954  */
 955 static inline void convert_burst(u32 *maxburst)
 956 {
 957         if (*maxburst > 1)
 958                 *maxburst = fls(*maxburst) - 2;
 959         else
 960                 *maxburst = 0;
 961 }
 962
 963 static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
 964 {
 965         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 966
 967         /* Check if chan will be configured for slave transfers */
 968         if (!is_slave_direction(sconfig->direction))
 969                 return -EINVAL;
 970
 971         memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig));
 972         dwc->direction = sconfig->direction;
 973
 974         convert_burst(&dwc->dma_sconfig.src_maxburst);
 975         convert_burst(&dwc->dma_sconfig.dst_maxburst);
 976
 977         return 0;
 978 }
 979
 980 static int dwc_pause(struct dma_chan *chan)
 981 {
 982         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 983         unsigned long           flags;
 984         unsigned int            count = 20;     /* timeout iterations */
 985         u32                     cfglo;
 986
 987         spin_lock_irqsave(&dwc->lock, flags);
 988
 989         cfglo = channel_readl(dwc, CFG_LO);
 990         channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
 991         while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY) && count--)
 992                 udelay(2);
 993
 994         dwc->paused = true;
 995
 996         spin_unlock_irqrestore(&dwc->lock, flags);
 997
 998         return 0;
 999 }
1000
1001 static inline void dwc_chan_resume(struct dw_dma_chan *dwc)
1002 {
1003         u32 cfglo = channel_readl(dwc, CFG_LO);
1004
1005         channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
1006
1007         dwc->paused = false;
1008 }
1009
1010 static int dwc_resume(struct dma_chan *chan)
1011 {
1012         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1013         unsigned long           flags;
1014
1015         if (!dwc->paused)
1016                 return 0;
1017
1018         spin_lock_irqsave(&dwc->lock, flags);
1019
1020         dwc_chan_resume(dwc);
1021
1022         spin_unlock_irqrestore(&dwc->lock, flags);
1023
1024         return 0;
1025 }
1026
1027 static int dwc_terminate_all(struct dma_chan *chan)
1028 {
1029         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1030         struct dw_dma           *dw = to_dw_dma(chan->device);
1031         struct dw_desc          *desc, *_desc;
1032         unsigned long           flags;
1033         LIST_HEAD(list);
1034
1035         spin_lock_irqsave(&dwc->lock, flags);
1036
1037         clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
1038
1039         dwc_chan_disable(dw, dwc);
1040
1041         dwc_chan_resume(dwc);
1042
1043         /* active_list entries will end up before queued entries */
1044         list_splice_init(&dwc->queue, &list);
1045         list_splice_init(&dwc->active_list, &list);
1046
1047         spin_unlock_irqrestore(&dwc->lock, flags);
1048
1049         /* Flush all pending and queued descriptors */
1050         list_for_each_entry_safe(desc, _desc, &list, desc_node)
1051                 dwc_descriptor_complete(dwc, desc, false);
1052
1053         return 0;
1054 }
1055
1056 static inline u32 dwc_get_residue(struct dw_dma_chan *dwc)
1057 {
1058         unsigned long flags;
1059         u32 residue;
1060
1061         spin_lock_irqsave(&dwc->lock, flags);
1062
1063         residue = dwc->residue;
1064         if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags) && residue)
1065                 residue -= dwc_get_sent(dwc);
1066
1067         spin_unlock_irqrestore(&dwc->lock, flags);
1068         return residue;
1069 }
1070
1071 static enum dma_status
1072 dwc_tx_status(struct dma_chan *chan,
1073               dma_cookie_t cookie,
1074               struct dma_tx_state *txstate)
1075 {
1076         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1077         enum dma_status         ret;
1078
1079         ret = dma_cookie_status(chan, cookie, txstate);
1080         if (ret == DMA_COMPLETE)
1081                 return ret;
1082
1083         dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
1084
1085         ret = dma_cookie_status(chan, cookie, txstate);
1086         if (ret != DMA_COMPLETE)
1087                 dma_set_residue(txstate, dwc_get_residue(dwc));
1088
1089         if (dwc->paused && ret == DMA_IN_PROGRESS)
1090                 return DMA_PAUSED;
1091
1092         return ret;
1093 }
1094
1095 static void dwc_issue_pending(struct dma_chan *chan)
1096 {
1097         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1098         unsigned long           flags;
1099
1100         spin_lock_irqsave(&dwc->lock, flags);
1101         if (list_empty(&dwc->active_list))
1102                 dwc_dostart_first_queued(dwc);
1103         spin_unlock_irqrestore(&dwc->lock, flags);
1104 }
1105
1106 /*----------------------------------------------------------------------*/
1107
1108 static void dw_dma_off(struct dw_dma *dw)
1109 {
1110         int i;
1111
1112         dma_writel(dw, CFG, 0);
1113
1114         channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1115         channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1116         channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1117         channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1118         channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1119
1120         while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
1121                 cpu_relax();
1122
1123         for (i = 0; i < dw->dma.chancnt; i++)
1124                 dw->chan[i].initialized = false;
1125 }
1126
1127 static void dw_dma_on(struct dw_dma *dw)
1128 {
1129         dma_writel(dw, CFG, DW_CFG_DMA_EN);
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         /*
1157          * We need controller-specific data to set up slave transfers.
1158          */
1159         if (chan->private && !dw_dma_filter(chan, chan->private)) {
1160                 dev_warn(chan2dev(chan), "Wrong controller-specific data\n");
1161                 return -EINVAL;
1162         }
1163
1164         /* Enable controller here if needed */
1165         if (!dw->in_use)
1166                 dw_dma_on(dw);
1167         dw->in_use |= dwc->mask;
1168
1169         spin_lock_irqsave(&dwc->lock, flags);
1170         i = dwc->descs_allocated;
1171         while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) {
1172                 dma_addr_t phys;
1173
1174                 spin_unlock_irqrestore(&dwc->lock, flags);
1175
1176                 desc = dma_pool_alloc(dw->desc_pool, GFP_ATOMIC, &phys);
1177                 if (!desc)
1178                         goto err_desc_alloc;
1179
1180                 memset(desc, 0, sizeof(struct dw_desc));
1181
1182                 INIT_LIST_HEAD(&desc->tx_list);
1183                 dma_async_tx_descriptor_init(&desc->txd, chan);
1184                 desc->txd.tx_submit = dwc_tx_submit;
1185                 desc->txd.flags = DMA_CTRL_ACK;
1186                 desc->txd.phys = phys;
1187
1188                 dwc_desc_put(dwc, desc);
1189
1190                 spin_lock_irqsave(&dwc->lock, flags);
1191                 i = ++dwc->descs_allocated;
1192         }
1193
1194         spin_unlock_irqrestore(&dwc->lock, flags);
1195
1196         dev_dbg(chan2dev(chan), "%s: allocated %d descriptors\n", __func__, i);
1197
1198         return i;
1199
1200 err_desc_alloc:
1201         dev_info(chan2dev(chan), "only allocated %d descriptors\n", i);
1202
1203         return i;
1204 }
1205
1206 static void dwc_free_chan_resources(struct dma_chan *chan)
1207 {
1208         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1209         struct dw_dma           *dw = to_dw_dma(chan->device);
1210         struct dw_desc          *desc, *_desc;
1211         unsigned long           flags;
1212         LIST_HEAD(list);
1213
1214         dev_dbg(chan2dev(chan), "%s: descs allocated=%u\n", __func__,
1215                         dwc->descs_allocated);
1216
1217         /* ASSERT:  channel is idle */
1218         BUG_ON(!list_empty(&dwc->active_list));
1219         BUG_ON(!list_empty(&dwc->queue));
1220         BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
1221
1222         spin_lock_irqsave(&dwc->lock, flags);
1223         list_splice_init(&dwc->free_list, &list);
1224         dwc->descs_allocated = 0;
1225
1226         /* Clear custom channel configuration */
1227         dwc->src_id = 0;
1228         dwc->dst_id = 0;
1229
1230         dwc->src_master = 0;
1231         dwc->dst_master = 0;
1232
1233         dwc->initialized = false;
1234
1235         /* Disable interrupts */
1236         channel_clear_bit(dw, MASK.XFER, dwc->mask);
1237         channel_clear_bit(dw, MASK.BLOCK, dwc->mask);
1238         channel_clear_bit(dw, MASK.ERROR, dwc->mask);
1239
1240         spin_unlock_irqrestore(&dwc->lock, flags);
1241
1242         /* Disable controller in case it was a last user */
1243         dw->in_use &= ~dwc->mask;
1244         if (!dw->in_use)
1245                 dw_dma_off(dw);
1246
1247         list_for_each_entry_safe(desc, _desc, &list, desc_node) {
1248                 dev_vdbg(chan2dev(chan), "  freeing descriptor %p\n", desc);
1249                 dma_pool_free(dw->desc_pool, desc, desc->txd.phys);
1250         }
1251
1252         dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
1253 }
1254
1255 /* --------------------- Cyclic DMA API extensions -------------------- */
1256
1257 /**
1258  * dw_dma_cyclic_start - start the cyclic DMA transfer
1259  * @chan: the DMA channel to start
1260  *
1261  * Must be called with soft interrupts disabled. Returns zero on success or
1262  * -errno on failure.
1263  */
1264 int dw_dma_cyclic_start(struct dma_chan *chan)
1265 {
1266         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1267         struct dw_dma           *dw = to_dw_dma(chan->device);
1268         unsigned long           flags;
1269
1270         if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
1271                 dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n");
1272                 return -ENODEV;
1273         }
1274
1275         spin_lock_irqsave(&dwc->lock, flags);
1276
1277         /* Enable interrupts to perform cyclic transfer */
1278         channel_set_bit(dw, MASK.BLOCK, dwc->mask);
1279
1280         dwc_dostart(dwc, dwc->cdesc->desc[0]);
1281
1282         spin_unlock_irqrestore(&dwc->lock, flags);
1283
1284         return 0;
1285 }
1286 EXPORT_SYMBOL(dw_dma_cyclic_start);
1287
1288 /**
1289  * dw_dma_cyclic_stop - stop the cyclic DMA transfer
1290  * @chan: the DMA channel to stop
1291  *
1292  * Must be called with soft interrupts disabled.
1293  */
1294 void dw_dma_cyclic_stop(struct dma_chan *chan)
1295 {
1296         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1297         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
1298         unsigned long           flags;
1299
1300         spin_lock_irqsave(&dwc->lock, flags);
1301
1302         dwc_chan_disable(dw, dwc);
1303
1304         spin_unlock_irqrestore(&dwc->lock, flags);
1305 }
1306 EXPORT_SYMBOL(dw_dma_cyclic_stop);
1307
1308 /**
1309  * dw_dma_cyclic_prep - prepare the cyclic DMA transfer
1310  * @chan: the DMA channel to prepare
1311  * @buf_addr: physical DMA address where the buffer starts
1312  * @buf_len: total number of bytes for the entire buffer
1313  * @period_len: number of bytes for each period
1314  * @direction: transfer direction, to or from device
1315  *
1316  * Must be called before trying to start the transfer. Returns a valid struct
1317  * dw_cyclic_desc if successful or an ERR_PTR(-errno) if not successful.
1318  */
1319 struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
1320                 dma_addr_t buf_addr, size_t buf_len, size_t period_len,
1321                 enum dma_transfer_direction direction)
1322 {
1323         struct dw_dma_chan              *dwc = to_dw_dma_chan(chan);
1324         struct dma_slave_config         *sconfig = &dwc->dma_sconfig;
1325         struct dw_cyclic_desc           *cdesc;
1326         struct dw_cyclic_desc           *retval = NULL;
1327         struct dw_desc                  *desc;
1328         struct dw_desc                  *last = NULL;
1329         unsigned long                   was_cyclic;
1330         unsigned int                    reg_width;
1331         unsigned int                    periods;
1332         unsigned int                    i;
1333         unsigned long                   flags;
1334
1335         spin_lock_irqsave(&dwc->lock, flags);
1336         if (dwc->nollp) {
1337                 spin_unlock_irqrestore(&dwc->lock, flags);
1338                 dev_dbg(chan2dev(&dwc->chan),
1339                                 "channel doesn't support LLP transfers\n");
1340                 return ERR_PTR(-EINVAL);
1341         }
1342
1343         if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) {
1344                 spin_unlock_irqrestore(&dwc->lock, flags);
1345                 dev_dbg(chan2dev(&dwc->chan),
1346                                 "queue and/or active list are not empty\n");
1347                 return ERR_PTR(-EBUSY);
1348         }
1349
1350         was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1351         spin_unlock_irqrestore(&dwc->lock, flags);
1352         if (was_cyclic) {
1353                 dev_dbg(chan2dev(&dwc->chan),
1354                                 "channel already prepared for cyclic DMA\n");
1355                 return ERR_PTR(-EBUSY);
1356         }
1357
1358         retval = ERR_PTR(-EINVAL);
1359
1360         if (unlikely(!is_slave_direction(direction)))
1361                 goto out_err;
1362
1363         dwc->direction = direction;
1364
1365         if (direction == DMA_MEM_TO_DEV)
1366                 reg_width = __ffs(sconfig->dst_addr_width);
1367         else
1368                 reg_width = __ffs(sconfig->src_addr_width);
1369
1370         periods = buf_len / period_len;
1371
1372         /* Check for too big/unaligned periods and unaligned DMA buffer. */
1373         if (period_len > (dwc->block_size << reg_width))
1374                 goto out_err;
1375         if (unlikely(period_len & ((1 << reg_width) - 1)))
1376                 goto out_err;
1377         if (unlikely(buf_addr & ((1 << reg_width) - 1)))
1378                 goto out_err;
1379
1380         retval = ERR_PTR(-ENOMEM);
1381
1382         if (periods > NR_DESCS_PER_CHANNEL)
1383                 goto out_err;
1384
1385         cdesc = kzalloc(sizeof(struct dw_cyclic_desc), GFP_KERNEL);
1386         if (!cdesc)
1387                 goto out_err;
1388
1389         cdesc->desc = kzalloc(sizeof(struct dw_desc *) * periods, GFP_KERNEL);
1390         if (!cdesc->desc)
1391                 goto out_err_alloc;
1392
1393         for (i = 0; i < periods; i++) {
1394                 desc = dwc_desc_get(dwc);
1395                 if (!desc)
1396                         goto out_err_desc_get;
1397
1398                 switch (direction) {
1399                 case DMA_MEM_TO_DEV:
1400                         desc->lli.dar = sconfig->dst_addr;
1401                         desc->lli.sar = buf_addr + (period_len * i);
1402                         desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan)
1403                                         | DWC_CTLL_DST_WIDTH(reg_width)
1404                                         | DWC_CTLL_SRC_WIDTH(reg_width)
1405                                         | DWC_CTLL_DST_FIX
1406                                         | DWC_CTLL_SRC_INC
1407                                         | DWC_CTLL_INT_EN);
1408
1409                         desc->lli.ctllo |= sconfig->device_fc ?
1410                                 DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
1411                                 DWC_CTLL_FC(DW_DMA_FC_D_M2P);
1412
1413                         break;
1414                 case DMA_DEV_TO_MEM:
1415                         desc->lli.dar = buf_addr + (period_len * i);
1416                         desc->lli.sar = sconfig->src_addr;
1417                         desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan)
1418                                         | DWC_CTLL_SRC_WIDTH(reg_width)
1419                                         | DWC_CTLL_DST_WIDTH(reg_width)
1420                                         | DWC_CTLL_DST_INC
1421                                         | DWC_CTLL_SRC_FIX
1422                                         | DWC_CTLL_INT_EN);
1423
1424                         desc->lli.ctllo |= sconfig->device_fc ?
1425                                 DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
1426                                 DWC_CTLL_FC(DW_DMA_FC_D_P2M);
1427
1428                         break;
1429                 default:
1430                         break;
1431                 }
1432
1433                 desc->lli.ctlhi = (period_len >> reg_width);
1434                 cdesc->desc[i] = desc;
1435
1436                 if (last)
1437                         last->lli.llp = desc->txd.phys;
1438
1439                 last = desc;
1440         }
1441
1442         /* Let's make a cyclic list */
1443         last->lli.llp = cdesc->desc[0]->txd.phys;
1444
1445         dev_dbg(chan2dev(&dwc->chan),
1446                         "cyclic prepared buf %pad len %zu period %zu periods %d\n",
1447                         &buf_addr, buf_len, period_len, periods);
1448
1449         cdesc->periods = periods;
1450         dwc->cdesc = cdesc;
1451
1452         return cdesc;
1453
1454 out_err_desc_get:
1455         while (i--)
1456                 dwc_desc_put(dwc, cdesc->desc[i]);
1457 out_err_alloc:
1458         kfree(cdesc);
1459 out_err:
1460         clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1461         return (struct dw_cyclic_desc *)retval;
1462 }
1463 EXPORT_SYMBOL(dw_dma_cyclic_prep);
1464
1465 /**
1466  * dw_dma_cyclic_free - free a prepared cyclic DMA transfer
1467  * @chan: the DMA channel to free
1468  */
1469 void dw_dma_cyclic_free(struct dma_chan *chan)
1470 {
1471         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1472         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
1473         struct dw_cyclic_desc   *cdesc = dwc->cdesc;
1474         int                     i;
1475         unsigned long           flags;
1476
1477         dev_dbg(chan2dev(&dwc->chan), "%s\n", __func__);
1478
1479         if (!cdesc)
1480                 return;
1481
1482         spin_lock_irqsave(&dwc->lock, flags);
1483
1484         dwc_chan_disable(dw, dwc);
1485
1486         dma_writel(dw, CLEAR.BLOCK, dwc->mask);
1487         dma_writel(dw, CLEAR.ERROR, dwc->mask);
1488         dma_writel(dw, CLEAR.XFER, dwc->mask);
1489
1490         spin_unlock_irqrestore(&dwc->lock, flags);
1491
1492         for (i = 0; i < cdesc->periods; i++)
1493                 dwc_desc_put(dwc, cdesc->desc[i]);
1494
1495         kfree(cdesc->desc);
1496         kfree(cdesc);
1497
1498         clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1499 }
1500 EXPORT_SYMBOL(dw_dma_cyclic_free);
1501
1502 /*----------------------------------------------------------------------*/
1503
1504 int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
1505 {
1506         struct dw_dma           *dw;
1507         bool                    autocfg = false;
1508         unsigned int            dw_params;
1509         unsigned int            max_blk_size = 0;
1510         int                     err;
1511         int                     i;
1512
1513         dw = devm_kzalloc(chip->dev, sizeof(*dw), GFP_KERNEL);
1514         if (!dw)
1515                 return -ENOMEM;
1516
1517         dw->regs = chip->regs;
1518         chip->dw = dw;
1519
1520         pm_runtime_get_sync(chip->dev);
1521
1522         if (!pdata) {
1523                 dw_params = dma_read_byaddr(chip->regs, DW_PARAMS);
1524                 dev_dbg(chip->dev, "DW_PARAMS: 0x%08x\n", dw_params);
1525
1526                 autocfg = dw_params >> DW_PARAMS_EN & 1;
1527                 if (!autocfg) {
1528                         err = -EINVAL;
1529                         goto err_pdata;
1530                 }
1531
1532                 pdata = devm_kzalloc(chip->dev, sizeof(*pdata), GFP_KERNEL);
1533                 if (!pdata) {
1534                         err = -ENOMEM;
1535                         goto err_pdata;
1536                 }
1537
1538                 /* Get hardware configuration parameters */
1539                 pdata->nr_channels = (dw_params >> DW_PARAMS_NR_CHAN & 7) + 1;
1540                 pdata->nr_masters = (dw_params >> DW_PARAMS_NR_MASTER & 3) + 1;
1541                 for (i = 0; i < pdata->nr_masters; i++) {
1542                         pdata->data_width[i] =
1543                                 (dw_params >> DW_PARAMS_DATA_WIDTH(i) & 3) + 2;
1544                 }
1545                 max_blk_size = dma_readl(dw, MAX_BLK_SIZE);
1546
1547                 /* Fill platform data with the default values */
1548                 pdata->is_private = true;
1549                 pdata->is_memcpy = true;
1550                 pdata->chan_allocation_order = CHAN_ALLOCATION_ASCENDING;
1551                 pdata->chan_priority = CHAN_PRIORITY_ASCENDING;
1552         } else if (pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS) {
1553                 err = -EINVAL;
1554                 goto err_pdata;
1555         }
1556
1557         dw->chan = devm_kcalloc(chip->dev, pdata->nr_channels, sizeof(*dw->chan),
1558                                 GFP_KERNEL);
1559         if (!dw->chan) {
1560                 err = -ENOMEM;
1561                 goto err_pdata;
1562         }
1563
1564         /* Get hardware configuration parameters */
1565         dw->nr_masters = pdata->nr_masters;
1566         for (i = 0; i < dw->nr_masters; i++)
1567                 dw->data_width[i] = pdata->data_width[i];
1568
1569         /* Calculate all channel mask before DMA setup */
1570         dw->all_chan_mask = (1 << pdata->nr_channels) - 1;
1571
1572         /* Force dma off, just in case */
1573         dw_dma_off(dw);
1574
1575         /* Create a pool of consistent memory blocks for hardware descriptors */
1576         dw->desc_pool = dmam_pool_create("dw_dmac_desc_pool", chip->dev,
1577                                          sizeof(struct dw_desc), 4, 0);
1578         if (!dw->desc_pool) {
1579                 dev_err(chip->dev, "No memory for descriptors dma pool\n");
1580                 err = -ENOMEM;
1581                 goto err_pdata;
1582         }
1583
1584         tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
1585
1586         err = request_irq(chip->irq, dw_dma_interrupt, IRQF_SHARED,
1587                           "dw_dmac", dw);
1588         if (err)
1589                 goto err_pdata;
1590
1591         INIT_LIST_HEAD(&dw->dma.channels);
1592         for (i = 0; i < pdata->nr_channels; i++) {
1593                 struct dw_dma_chan      *dwc = &dw->chan[i];
1594
1595                 dwc->chan.device = &dw->dma;
1596                 dma_cookie_init(&dwc->chan);
1597                 if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING)
1598                         list_add_tail(&dwc->chan.device_node,
1599                                         &dw->dma.channels);
1600                 else
1601                         list_add(&dwc->chan.device_node, &dw->dma.channels);
1602
1603                 /* 7 is highest priority & 0 is lowest. */
1604                 if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING)
1605                         dwc->priority = pdata->nr_channels - i - 1;
1606                 else
1607                         dwc->priority = i;
1608
1609                 dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
1610                 spin_lock_init(&dwc->lock);
1611                 dwc->mask = 1 << i;
1612
1613                 INIT_LIST_HEAD(&dwc->active_list);
1614                 INIT_LIST_HEAD(&dwc->queue);
1615                 INIT_LIST_HEAD(&dwc->free_list);
1616
1617                 channel_clear_bit(dw, CH_EN, dwc->mask);
1618
1619                 dwc->direction = DMA_TRANS_NONE;
1620
1621                 /* Hardware configuration */
1622                 if (autocfg) {
1623                         unsigned int dwc_params;
1624                         unsigned int r = DW_DMA_MAX_NR_CHANNELS - i - 1;
1625                         void __iomem *addr = chip->regs + r * sizeof(u32);
1626
1627                         dwc_params = dma_read_byaddr(addr, DWC_PARAMS);
1628
1629                         dev_dbg(chip->dev, "DWC_PARAMS[%d]: 0x%08x\n", i,
1630                                            dwc_params);
1631
1632                         /*
1633                          * Decode maximum block size for given channel. The
1634                          * stored 4 bit value represents blocks from 0x00 for 3
1635                          * up to 0x0a for 4095.
1636                          */
1637                         dwc->block_size =
1638                                 (4 << ((max_blk_size >> 4 * i) & 0xf)) - 1;
1639                         dwc->nollp =
1640                                 (dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0;
1641                 } else {
1642                         dwc->block_size = pdata->block_size;
1643
1644                         /* Check if channel supports multi block transfer */
1645                         channel_writel(dwc, LLP, 0xfffffffc);
1646                         dwc->nollp =
1647                                 (channel_readl(dwc, LLP) & 0xfffffffc) == 0;
1648                         channel_writel(dwc, LLP, 0);
1649                 }
1650         }
1651
1652         /* Clear all interrupts on all channels. */
1653         dma_writel(dw, CLEAR.XFER, dw->all_chan_mask);
1654         dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask);
1655         dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask);
1656         dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask);
1657         dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask);
1658
1659         /* Set capabilities */
1660         dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
1661         if (pdata->is_private)
1662                 dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask);
1663         if (pdata->is_memcpy)
1664                 dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
1665
1666         dw->dma.dev = chip->dev;
1667         dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
1668         dw->dma.device_free_chan_resources = dwc_free_chan_resources;
1669
1670         dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
1671         dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
1672
1673         dw->dma.device_config = dwc_config;
1674         dw->dma.device_pause = dwc_pause;
1675         dw->dma.device_resume = dwc_resume;
1676         dw->dma.device_terminate_all = dwc_terminate_all;
1677
1678         dw->dma.device_tx_status = dwc_tx_status;
1679         dw->dma.device_issue_pending = dwc_issue_pending;
1680
1681         /* DMA capabilities */
1682         dw->dma.src_addr_widths = DW_DMA_BUSWIDTHS;
1683         dw->dma.dst_addr_widths = DW_DMA_BUSWIDTHS;
1684         dw->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
1685                              BIT(DMA_MEM_TO_MEM);
1686         dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1687
1688         err = dma_async_device_register(&dw->dma);
1689         if (err)
1690                 goto err_dma_register;
1691
1692         dev_info(chip->dev, "DesignWare DMA Controller, %d channels\n",
1693                  pdata->nr_channels);
1694
1695         pm_runtime_put_sync_suspend(chip->dev);
1696
1697         return 0;
1698
1699 err_dma_register:
1700         free_irq(chip->irq, dw);
1701 err_pdata:
1702         pm_runtime_put_sync_suspend(chip->dev);
1703         return err;
1704 }
1705 EXPORT_SYMBOL_GPL(dw_dma_probe);
1706
1707 int dw_dma_remove(struct dw_dma_chip *chip)
1708 {
1709         struct dw_dma           *dw = chip->dw;
1710         struct dw_dma_chan      *dwc, *_dwc;
1711
1712         pm_runtime_get_sync(chip->dev);
1713
1714         dw_dma_off(dw);
1715         dma_async_device_unregister(&dw->dma);
1716
1717         free_irq(chip->irq, dw);
1718         tasklet_kill(&dw->tasklet);
1719
1720         list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,
1721                         chan.device_node) {
1722                 list_del(&dwc->chan.device_node);
1723                 channel_clear_bit(dw, CH_EN, dwc->mask);
1724         }
1725
1726         pm_runtime_put_sync_suspend(chip->dev);
1727         return 0;
1728 }
1729 EXPORT_SYMBOL_GPL(dw_dma_remove);
1730
1731 int dw_dma_disable(struct dw_dma_chip *chip)
1732 {
1733         struct dw_dma *dw = chip->dw;
1734
1735         dw_dma_off(dw);
1736         return 0;
1737 }
1738 EXPORT_SYMBOL_GPL(dw_dma_disable);
1739
1740 int dw_dma_enable(struct dw_dma_chip *chip)
1741 {
1742         struct dw_dma *dw = chip->dw;
1743
1744         dw_dma_on(dw);
1745         return 0;
1746 }
1747 EXPORT_SYMBOL_GPL(dw_dma_enable);
1748
1749 MODULE_LICENSE("GPL v2");
1750 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller core driver");
1751 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
1752 MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");