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         struct dw_dma_slave *dws = dwc->chan.private;
 134         u32 cfghi = DWC_CFGH_FIFO_MODE;
 135         u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
 136
 137         if (dwc->initialized == true)
 138                 return;
 139
 140         if (dws) {
 141                 /*
 142                  * We need controller-specific data to set up slave
 143                  * transfers.
 144                  */
 145                 BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev);
 146
 147                 cfghi |= DWC_CFGH_DST_PER(dws->dst_id);
 148                 cfghi |= DWC_CFGH_SRC_PER(dws->src_id);
 149         } else {
 150                 cfghi |= DWC_CFGH_DST_PER(dwc->dst_id);
 151                 cfghi |= DWC_CFGH_SRC_PER(dwc->src_id);
 152         }
 153
 154         channel_writel(dwc, CFG_LO, cfglo);
 155         channel_writel(dwc, CFG_HI, cfghi);
 156
 157         /* Enable interrupts */
 158         channel_set_bit(dw, MASK.XFER, dwc->mask);
 159         channel_set_bit(dw, MASK.BLOCK, dwc->mask);
 160         channel_set_bit(dw, MASK.ERROR, dwc->mask);
 161
 162         dwc->initialized = true;
 163 }
 164
 165 /*----------------------------------------------------------------------*/
 166
 167 static inline unsigned int dwc_fast_ffs(unsigned long long v)
 168 {
 169         /*
 170          * We can be a lot more clever here, but this should take care
 171          * of the most common optimization.
 172          */
 173         if (!(v & 7))
 174                 return 3;
 175         else if (!(v & 3))
 176                 return 2;
 177         else if (!(v & 1))
 178                 return 1;
 179         return 0;
 180 }
 181
 182 static inline void dwc_dump_chan_regs(struct dw_dma_chan *dwc)
 183 {
 184         dev_err(chan2dev(&dwc->chan),
 185                 "  SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
 186                 channel_readl(dwc, SAR),
 187                 channel_readl(dwc, DAR),
 188                 channel_readl(dwc, LLP),
 189                 channel_readl(dwc, CTL_HI),
 190                 channel_readl(dwc, CTL_LO));
 191 }
 192
 193 static inline void dwc_chan_disable(struct dw_dma *dw, struct dw_dma_chan *dwc)
 194 {
 195         channel_clear_bit(dw, CH_EN, dwc->mask);
 196         while (dma_readl(dw, CH_EN) & dwc->mask)
 197                 cpu_relax();
 198 }
 199
 200 /*----------------------------------------------------------------------*/
 201
 202 /* Perform single block transfer */
 203 static inline void dwc_do_single_block(struct dw_dma_chan *dwc,
 204                                        struct dw_desc *desc)
 205 {
 206         struct dw_dma   *dw = to_dw_dma(dwc->chan.device);
 207         u32             ctllo;
 208
 209         /*
 210          * Software emulation of LLP mode relies on interrupts to continue
 211          * multi block transfer.
 212          */
 213         ctllo = desc->lli.ctllo | DWC_CTLL_INT_EN;
 214
 215         channel_writel(dwc, SAR, desc->lli.sar);
 216         channel_writel(dwc, DAR, desc->lli.dar);
 217         channel_writel(dwc, CTL_LO, ctllo);
 218         channel_writel(dwc, CTL_HI, desc->lli.ctlhi);
 219         channel_set_bit(dw, CH_EN, dwc->mask);
 220
 221         /* Move pointer to next descriptor */
 222         dwc->tx_node_active = dwc->tx_node_active->next;
 223 }
 224
 225 /* Called with dwc->lock held and bh disabled */
 226 static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
 227 {
 228         struct dw_dma   *dw = to_dw_dma(dwc->chan.device);
 229         unsigned long   was_soft_llp;
 230
 231         /* ASSERT:  channel is idle */
 232         if (dma_readl(dw, CH_EN) & dwc->mask) {
 233                 dev_err(chan2dev(&dwc->chan),
 234                         "%s: BUG: Attempted to start non-idle channel\n",
 235                         __func__);
 236                 dwc_dump_chan_regs(dwc);
 237
 238                 /* The tasklet will hopefully advance the queue... */
 239                 return;
 240         }
 241
 242         if (dwc->nollp) {
 243                 was_soft_llp = test_and_set_bit(DW_DMA_IS_SOFT_LLP,
 244                                                 &dwc->flags);
 245                 if (was_soft_llp) {
 246                         dev_err(chan2dev(&dwc->chan),
 247                                 "BUG: Attempted to start new LLP transfer inside ongoing one\n");
 248                         return;
 249                 }
 250
 251                 dwc_initialize(dwc);
 252
 253                 dwc->residue = first->total_len;
 254                 dwc->tx_node_active = &first->tx_list;
 255
 256                 /* Submit first block */
 257                 dwc_do_single_block(dwc, first);
 258
 259                 return;
 260         }
 261
 262         dwc_initialize(dwc);
 263
 264         channel_writel(dwc, LLP, first->txd.phys);
 265         channel_writel(dwc, CTL_LO,
 266                         DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
 267         channel_writel(dwc, CTL_HI, 0);
 268         channel_set_bit(dw, CH_EN, dwc->mask);
 269 }
 270
 271 static void dwc_dostart_first_queued(struct dw_dma_chan *dwc)
 272 {
 273         struct dw_desc *desc;
 274
 275         if (list_empty(&dwc->queue))
 276                 return;
 277
 278         list_move(dwc->queue.next, &dwc->active_list);
 279         desc = dwc_first_active(dwc);
 280         dev_vdbg(chan2dev(&dwc->chan), "%s: started %u\n", __func__, desc->txd.cookie);
 281         dwc_dostart(dwc, desc);
 282 }
 283
 284 /*----------------------------------------------------------------------*/
 285
 286 static void
 287 dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc,
 288                 bool callback_required)
 289 {
 290         dma_async_tx_callback           callback = NULL;
 291         void                            *param = NULL;
 292         struct dma_async_tx_descriptor  *txd = &desc->txd;
 293         struct dw_desc                  *child;
 294         unsigned long                   flags;
 295
 296         dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
 297
 298         spin_lock_irqsave(&dwc->lock, flags);
 299         dma_cookie_complete(txd);
 300         if (callback_required) {
 301                 callback = txd->callback;
 302                 param = txd->callback_param;
 303         }
 304
 305         /* async_tx_ack */
 306         list_for_each_entry(child, &desc->tx_list, desc_node)
 307                 async_tx_ack(&child->txd);
 308         async_tx_ack(&desc->txd);
 309
 310         list_splice_init(&desc->tx_list, &dwc->free_list);
 311         list_move(&desc->desc_node, &dwc->free_list);
 312
 313         dma_descriptor_unmap(txd);
 314         spin_unlock_irqrestore(&dwc->lock, flags);
 315
 316         if (callback)
 317                 callback(param);
 318 }
 319
 320 static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
 321 {
 322         struct dw_desc *desc, *_desc;
 323         LIST_HEAD(list);
 324         unsigned long flags;
 325
 326         spin_lock_irqsave(&dwc->lock, flags);
 327         if (dma_readl(dw, CH_EN) & dwc->mask) {
 328                 dev_err(chan2dev(&dwc->chan),
 329                         "BUG: XFER bit set, but channel not idle!\n");
 330
 331                 /* Try to continue after resetting the channel... */
 332                 dwc_chan_disable(dw, dwc);
 333         }
 334
 335         /*
 336          * Submit queued descriptors ASAP, i.e. before we go through
 337          * the completed ones.
 338          */
 339         list_splice_init(&dwc->active_list, &list);
 340         dwc_dostart_first_queued(dwc);
 341
 342         spin_unlock_irqrestore(&dwc->lock, flags);
 343
 344         list_for_each_entry_safe(desc, _desc, &list, desc_node)
 345                 dwc_descriptor_complete(dwc, desc, true);
 346 }
 347
 348 /* Returns how many bytes were already received from source */
 349 static inline u32 dwc_get_sent(struct dw_dma_chan *dwc)
 350 {
 351         u32 ctlhi = channel_readl(dwc, CTL_HI);
 352         u32 ctllo = channel_readl(dwc, CTL_LO);
 353
 354         return (ctlhi & DWC_CTLH_BLOCK_TS_MASK) * (1 << (ctllo >> 4 & 7));
 355 }
 356
 357 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
 358 {
 359         dma_addr_t llp;
 360         struct dw_desc *desc, *_desc;
 361         struct dw_desc *child;
 362         u32 status_xfer;
 363         unsigned long flags;
 364
 365         spin_lock_irqsave(&dwc->lock, flags);
 366         llp = channel_readl(dwc, LLP);
 367         status_xfer = dma_readl(dw, RAW.XFER);
 368
 369         if (status_xfer & dwc->mask) {
 370                 /* Everything we've submitted is done */
 371                 dma_writel(dw, CLEAR.XFER, dwc->mask);
 372
 373                 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
 374                         struct list_head *head, *active = dwc->tx_node_active;
 375
 376                         /*
 377                          * We are inside first active descriptor.
 378                          * Otherwise something is really wrong.
 379                          */
 380                         desc = dwc_first_active(dwc);
 381
 382                         head = &desc->tx_list;
 383                         if (active != head) {
 384                                 /* Update desc to reflect last sent one */
 385                                 if (active != head->next)
 386                                         desc = to_dw_desc(active->prev);
 387
 388                                 dwc->residue -= desc->len;
 389
 390                                 child = to_dw_desc(active);
 391
 392                                 /* Submit next block */
 393                                 dwc_do_single_block(dwc, child);
 394
 395                                 spin_unlock_irqrestore(&dwc->lock, flags);
 396                                 return;
 397                         }
 398
 399                         /* We are done here */
 400                         clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
 401                 }
 402
 403                 dwc->residue = 0;
 404
 405                 spin_unlock_irqrestore(&dwc->lock, flags);
 406
 407                 dwc_complete_all(dw, dwc);
 408                 return;
 409         }
 410
 411         if (list_empty(&dwc->active_list)) {
 412                 dwc->residue = 0;
 413                 spin_unlock_irqrestore(&dwc->lock, flags);
 414                 return;
 415         }
 416
 417         if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
 418                 dev_vdbg(chan2dev(&dwc->chan), "%s: soft LLP mode\n", __func__);
 419                 spin_unlock_irqrestore(&dwc->lock, flags);
 420                 return;
 421         }
 422
 423         dev_vdbg(chan2dev(&dwc->chan), "%s: llp=%pad\n", __func__, &llp);
 424
 425         list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
 426                 /* Initial residue value */
 427                 dwc->residue = desc->total_len;
 428
 429                 /* Check first descriptors addr */
 430                 if (desc->txd.phys == llp) {
 431                         spin_unlock_irqrestore(&dwc->lock, flags);
 432                         return;
 433                 }
 434
 435                 /* Check first descriptors llp */
 436                 if (desc->lli.llp == llp) {
 437                         /* This one is currently in progress */
 438                         dwc->residue -= dwc_get_sent(dwc);
 439                         spin_unlock_irqrestore(&dwc->lock, flags);
 440                         return;
 441                 }
 442
 443                 dwc->residue -= desc->len;
 444                 list_for_each_entry(child, &desc->tx_list, desc_node) {
 445                         if (child->lli.llp == llp) {
 446                                 /* Currently in progress */
 447                                 dwc->residue -= dwc_get_sent(dwc);
 448                                 spin_unlock_irqrestore(&dwc->lock, flags);
 449                                 return;
 450                         }
 451                         dwc->residue -= child->len;
 452                 }
 453
 454                 /*
 455                  * No descriptors so far seem to be in progress, i.e.
 456                  * this one must be done.
 457                  */
 458                 spin_unlock_irqrestore(&dwc->lock, flags);
 459                 dwc_descriptor_complete(dwc, desc, true);
 460                 spin_lock_irqsave(&dwc->lock, flags);
 461         }
 462
 463         dev_err(chan2dev(&dwc->chan),
 464                 "BUG: All descriptors done, but channel not idle!\n");
 465
 466         /* Try to continue after resetting the channel... */
 467         dwc_chan_disable(dw, dwc);
 468
 469         dwc_dostart_first_queued(dwc);
 470         spin_unlock_irqrestore(&dwc->lock, flags);
 471 }
 472
 473 static inline void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli)
 474 {
 475         dev_crit(chan2dev(&dwc->chan), "  desc: s0x%x d0x%x l0x%x c0x%x:%x\n",
 476                  lli->sar, lli->dar, lli->llp, lli->ctlhi, lli->ctllo);
 477 }
 478
 479 static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
 480 {
 481         struct dw_desc *bad_desc;
 482         struct dw_desc *child;
 483         unsigned long flags;
 484
 485         dwc_scan_descriptors(dw, dwc);
 486
 487         spin_lock_irqsave(&dwc->lock, flags);
 488
 489         /*
 490          * The descriptor currently at the head of the active list is
 491          * borked. Since we don't have any way to report errors, we'll
 492          * just have to scream loudly and try to carry on.
 493          */
 494         bad_desc = dwc_first_active(dwc);
 495         list_del_init(&bad_desc->desc_node);
 496         list_move(dwc->queue.next, dwc->active_list.prev);
 497
 498         /* Clear the error flag and try to restart the controller */
 499         dma_writel(dw, CLEAR.ERROR, dwc->mask);
 500         if (!list_empty(&dwc->active_list))
 501                 dwc_dostart(dwc, dwc_first_active(dwc));
 502
 503         /*
 504          * WARN may seem harsh, but since this only happens
 505          * when someone submits a bad physical address in a
 506          * descriptor, we should consider ourselves lucky that the
 507          * controller flagged an error instead of scribbling over
 508          * random memory locations.
 509          */
 510         dev_WARN(chan2dev(&dwc->chan), "Bad descriptor submitted for DMA!\n"
 511                                        "  cookie: %d\n", bad_desc->txd.cookie);
 512         dwc_dump_lli(dwc, &bad_desc->lli);
 513         list_for_each_entry(child, &bad_desc->tx_list, desc_node)
 514                 dwc_dump_lli(dwc, &child->lli);
 515
 516         spin_unlock_irqrestore(&dwc->lock, flags);
 517
 518         /* Pretend the descriptor completed successfully */
 519         dwc_descriptor_complete(dwc, bad_desc, true);
 520 }
 521
 522 /* --------------------- Cyclic DMA API extensions -------------------- */
 523
 524 dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan)
 525 {
 526         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 527         return channel_readl(dwc, SAR);
 528 }
 529 EXPORT_SYMBOL(dw_dma_get_src_addr);
 530
 531 dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan)
 532 {
 533         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 534         return channel_readl(dwc, DAR);
 535 }
 536 EXPORT_SYMBOL(dw_dma_get_dst_addr);
 537
 538 /* Called with dwc->lock held and all DMAC interrupts disabled */
 539 static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
 540                 u32 status_block, u32 status_err, u32 status_xfer)
 541 {
 542         unsigned long flags;
 543
 544         if (status_block & dwc->mask) {
 545                 void (*callback)(void *param);
 546                 void *callback_param;
 547
 548                 dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp 0x%08x\n",
 549                                 channel_readl(dwc, LLP));
 550                 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
 551
 552                 callback = dwc->cdesc->period_callback;
 553                 callback_param = dwc->cdesc->period_callback_param;
 554
 555                 if (callback)
 556                         callback(callback_param);
 557         }
 558
 559         /*
 560          * Error and transfer complete are highly unlikely, and will most
 561          * likely be due to a configuration error by the user.
 562          */
 563         if (unlikely(status_err & dwc->mask) ||
 564                         unlikely(status_xfer & dwc->mask)) {
 565                 int i;
 566
 567                 dev_err(chan2dev(&dwc->chan),
 568                         "cyclic DMA unexpected %s interrupt, stopping DMA transfer\n",
 569                         status_xfer ? "xfer" : "error");
 570
 571                 spin_lock_irqsave(&dwc->lock, flags);
 572
 573                 dwc_dump_chan_regs(dwc);
 574
 575                 dwc_chan_disable(dw, dwc);
 576
 577                 /* Make sure DMA does not restart by loading a new list */
 578                 channel_writel(dwc, LLP, 0);
 579                 channel_writel(dwc, CTL_LO, 0);
 580                 channel_writel(dwc, CTL_HI, 0);
 581
 582                 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
 583                 dma_writel(dw, CLEAR.ERROR, dwc->mask);
 584                 dma_writel(dw, CLEAR.XFER, dwc->mask);
 585
 586                 for (i = 0; i < dwc->cdesc->periods; i++)
 587                         dwc_dump_lli(dwc, &dwc->cdesc->desc[i]->lli);
 588
 589                 spin_unlock_irqrestore(&dwc->lock, flags);
 590         }
 591 }
 592
 593 /* ------------------------------------------------------------------------- */
 594
 595 static void dw_dma_tasklet(unsigned long data)
 596 {
 597         struct dw_dma *dw = (struct dw_dma *)data;
 598         struct dw_dma_chan *dwc;
 599         u32 status_block;
 600         u32 status_xfer;
 601         u32 status_err;
 602         int i;
 603
 604         status_block = dma_readl(dw, RAW.BLOCK);
 605         status_xfer = dma_readl(dw, RAW.XFER);
 606         status_err = dma_readl(dw, RAW.ERROR);
 607
 608         dev_vdbg(dw->dma.dev, "%s: status_err=%x\n", __func__, status_err);
 609
 610         for (i = 0; i < dw->dma.chancnt; i++) {
 611                 dwc = &dw->chan[i];
 612                 if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
 613                         dwc_handle_cyclic(dw, dwc, status_block, status_err,
 614                                         status_xfer);
 615                 else if (status_err & (1 << i))
 616                         dwc_handle_error(dw, dwc);
 617                 else if (status_xfer & (1 << i))
 618                         dwc_scan_descriptors(dw, dwc);
 619         }
 620
 621         /*
 622          * Re-enable interrupts.
 623          */
 624         channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
 625         channel_set_bit(dw, MASK.BLOCK, dw->all_chan_mask);
 626         channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask);
 627 }
 628
 629 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
 630 {
 631         struct dw_dma *dw = dev_id;
 632         u32 status;
 633
 634         /* Check if we have any interrupt from the DMAC which is not in use */
 635         if (!dw->in_use)
 636                 return IRQ_NONE;
 637
 638         status = dma_readl(dw, STATUS_INT);
 639         dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__, status);
 640
 641         /* Check if we have any interrupt from the DMAC */
 642         if (!status)
 643                 return IRQ_NONE;
 644
 645         /*
 646          * Just disable the interrupts. We'll turn them back on in the
 647          * softirq handler.
 648          */
 649         channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
 650         channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
 651         channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
 652
 653         status = dma_readl(dw, STATUS_INT);
 654         if (status) {
 655                 dev_err(dw->dma.dev,
 656                         "BUG: Unexpected interrupts pending: 0x%x\n",
 657                         status);
 658
 659                 /* Try to recover */
 660                 channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1);
 661                 channel_clear_bit(dw, MASK.BLOCK, (1 << 8) - 1);
 662                 channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1);
 663                 channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1);
 664                 channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1);
 665         }
 666
 667         tasklet_schedule(&dw->tasklet);
 668
 669         return IRQ_HANDLED;
 670 }
 671
 672 /*----------------------------------------------------------------------*/
 673
 674 static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
 675 {
 676         struct dw_desc          *desc = txd_to_dw_desc(tx);
 677         struct dw_dma_chan      *dwc = to_dw_dma_chan(tx->chan);
 678         dma_cookie_t            cookie;
 679         unsigned long           flags;
 680
 681         spin_lock_irqsave(&dwc->lock, flags);
 682         cookie = dma_cookie_assign(tx);
 683
 684         /*
 685          * REVISIT: We should attempt to chain as many descriptors as
 686          * possible, perhaps even appending to those already submitted
 687          * for DMA. But this is hard to do in a race-free manner.
 688          */
 689
 690         dev_vdbg(chan2dev(tx->chan), "%s: queued %u\n", __func__, desc->txd.cookie);
 691         list_add_tail(&desc->desc_node, &dwc->queue);
 692
 693         spin_unlock_irqrestore(&dwc->lock, flags);
 694
 695         return cookie;
 696 }
 697
 698 static struct dma_async_tx_descriptor *
 699 dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 700                 size_t len, unsigned long flags)
 701 {
 702         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 703         struct dw_dma           *dw = to_dw_dma(chan->device);
 704         struct dw_desc          *desc;
 705         struct dw_desc          *first;
 706         struct dw_desc          *prev;
 707         size_t                  xfer_count;
 708         size_t                  offset;
 709         unsigned int            src_width;
 710         unsigned int            dst_width;
 711         unsigned int            data_width;
 712         u32                     ctllo;
 713
 714         dev_vdbg(chan2dev(chan),
 715                         "%s: d%pad s%pad l0x%zx f0x%lx\n", __func__,
 716                         &dest, &src, len, flags);
 717
 718         if (unlikely(!len)) {
 719                 dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__);
 720                 return NULL;
 721         }
 722
 723         dwc->direction = DMA_MEM_TO_MEM;
 724
 725         data_width = min_t(unsigned int, dw->data_width[dwc->src_master],
 726                            dw->data_width[dwc->dst_master]);
 727
 728         src_width = dst_width = min_t(unsigned int, data_width,
 729                                       dwc_fast_ffs(src | dest | len));
 730
 731         ctllo = DWC_DEFAULT_CTLLO(chan)
 732                         | DWC_CTLL_DST_WIDTH(dst_width)
 733                         | DWC_CTLL_SRC_WIDTH(src_width)
 734                         | DWC_CTLL_DST_INC
 735                         | DWC_CTLL_SRC_INC
 736                         | DWC_CTLL_FC_M2M;
 737         prev = first = NULL;
 738
 739         for (offset = 0; offset < len; offset += xfer_count << src_width) {
 740                 xfer_count = min_t(size_t, (len - offset) >> src_width,
 741                                            dwc->block_size);
 742
 743                 desc = dwc_desc_get(dwc);
 744                 if (!desc)
 745                         goto err_desc_get;
 746
 747                 desc->lli.sar = src + offset;
 748                 desc->lli.dar = dest + offset;
 749                 desc->lli.ctllo = ctllo;
 750                 desc->lli.ctlhi = xfer_count;
 751                 desc->len = xfer_count << src_width;
 752
 753                 if (!first) {
 754                         first = desc;
 755                 } else {
 756                         prev->lli.llp = desc->txd.phys;
 757                         list_add_tail(&desc->desc_node,
 758                                         &first->tx_list);
 759                 }
 760                 prev = desc;
 761         }
 762
 763         if (flags & DMA_PREP_INTERRUPT)
 764                 /* Trigger interrupt after last block */
 765                 prev->lli.ctllo |= DWC_CTLL_INT_EN;
 766
 767         prev->lli.llp = 0;
 768         first->txd.flags = flags;
 769         first->total_len = len;
 770
 771         return &first->txd;
 772
 773 err_desc_get:
 774         dwc_desc_put(dwc, first);
 775         return NULL;
 776 }
 777
 778 static struct dma_async_tx_descriptor *
 779 dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 780                 unsigned int sg_len, enum dma_transfer_direction direction,
 781                 unsigned long flags, void *context)
 782 {
 783         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 784         struct dw_dma           *dw = to_dw_dma(chan->device);
 785         struct dma_slave_config *sconfig = &dwc->dma_sconfig;
 786         struct dw_desc          *prev;
 787         struct dw_desc          *first;
 788         u32                     ctllo;
 789         dma_addr_t              reg;
 790         unsigned int            reg_width;
 791         unsigned int            mem_width;
 792         unsigned int            data_width;
 793         unsigned int            i;
 794         struct scatterlist      *sg;
 795         size_t                  total_len = 0;
 796
 797         dev_vdbg(chan2dev(chan), "%s\n", __func__);
 798
 799         if (unlikely(!is_slave_direction(direction) || !sg_len))
 800                 return NULL;
 801
 802         dwc->direction = direction;
 803
 804         prev = first = NULL;
 805
 806         switch (direction) {
 807         case DMA_MEM_TO_DEV:
 808                 reg_width = __ffs(sconfig->dst_addr_width);
 809                 reg = sconfig->dst_addr;
 810                 ctllo = (DWC_DEFAULT_CTLLO(chan)
 811                                 | DWC_CTLL_DST_WIDTH(reg_width)
 812                                 | DWC_CTLL_DST_FIX
 813                                 | DWC_CTLL_SRC_INC);
 814
 815                 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
 816                         DWC_CTLL_FC(DW_DMA_FC_D_M2P);
 817
 818                 data_width = dw->data_width[dwc->src_master];
 819
 820                 for_each_sg(sgl, sg, sg_len, i) {
 821                         struct dw_desc  *desc;
 822                         u32             len, dlen, mem;
 823
 824                         mem = sg_dma_address(sg);
 825                         len = sg_dma_len(sg);
 826
 827                         mem_width = min_t(unsigned int,
 828                                           data_width, dwc_fast_ffs(mem | len));
 829
 830 slave_sg_todev_fill_desc:
 831                         desc = dwc_desc_get(dwc);
 832                         if (!desc)
 833                                 goto err_desc_get;
 834
 835                         desc->lli.sar = mem;
 836                         desc->lli.dar = reg;
 837                         desc->lli.ctllo = ctllo | DWC_CTLL_SRC_WIDTH(mem_width);
 838                         if ((len >> mem_width) > dwc->block_size) {
 839                                 dlen = dwc->block_size << mem_width;
 840                                 mem += dlen;
 841                                 len -= dlen;
 842                         } else {
 843                                 dlen = len;
 844                                 len = 0;
 845                         }
 846
 847                         desc->lli.ctlhi = dlen >> mem_width;
 848                         desc->len = dlen;
 849
 850                         if (!first) {
 851                                 first = desc;
 852                         } else {
 853                                 prev->lli.llp = desc->txd.phys;
 854                                 list_add_tail(&desc->desc_node,
 855                                                 &first->tx_list);
 856                         }
 857                         prev = desc;
 858                         total_len += dlen;
 859
 860                         if (len)
 861                                 goto slave_sg_todev_fill_desc;
 862                 }
 863                 break;
 864         case DMA_DEV_TO_MEM:
 865                 reg_width = __ffs(sconfig->src_addr_width);
 866                 reg = sconfig->src_addr;
 867                 ctllo = (DWC_DEFAULT_CTLLO(chan)
 868                                 | DWC_CTLL_SRC_WIDTH(reg_width)
 869                                 | DWC_CTLL_DST_INC
 870                                 | DWC_CTLL_SRC_FIX);
 871
 872                 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
 873                         DWC_CTLL_FC(DW_DMA_FC_D_P2M);
 874
 875                 data_width = dw->data_width[dwc->dst_master];
 876
 877                 for_each_sg(sgl, sg, sg_len, i) {
 878                         struct dw_desc  *desc;
 879                         u32             len, dlen, mem;
 880
 881                         mem = sg_dma_address(sg);
 882                         len = sg_dma_len(sg);
 883
 884                         mem_width = min_t(unsigned int,
 885                                           data_width, dwc_fast_ffs(mem | len));
 886
 887 slave_sg_fromdev_fill_desc:
 888                         desc = dwc_desc_get(dwc);
 889                         if (!desc)
 890                                 goto err_desc_get;
 891
 892                         desc->lli.sar = reg;
 893                         desc->lli.dar = mem;
 894                         desc->lli.ctllo = ctllo | DWC_CTLL_DST_WIDTH(mem_width);
 895                         if ((len >> reg_width) > dwc->block_size) {
 896                                 dlen = dwc->block_size << reg_width;
 897                                 mem += dlen;
 898                                 len -= dlen;
 899                         } else {
 900                                 dlen = len;
 901                                 len = 0;
 902                         }
 903                         desc->lli.ctlhi = dlen >> reg_width;
 904                         desc->len = dlen;
 905
 906                         if (!first) {
 907                                 first = desc;
 908                         } else {
 909                                 prev->lli.llp = desc->txd.phys;
 910                                 list_add_tail(&desc->desc_node,
 911                                                 &first->tx_list);
 912                         }
 913                         prev = desc;
 914                         total_len += dlen;
 915
 916                         if (len)
 917                                 goto slave_sg_fromdev_fill_desc;
 918                 }
 919                 break;
 920         default:
 921                 return NULL;
 922         }
 923
 924         if (flags & DMA_PREP_INTERRUPT)
 925                 /* Trigger interrupt after last block */
 926                 prev->lli.ctllo |= DWC_CTLL_INT_EN;
 927
 928         prev->lli.llp = 0;
 929         first->total_len = total_len;
 930
 931         return &first->txd;
 932
 933 err_desc_get:
 934         dev_err(chan2dev(chan),
 935                 "not enough descriptors available. Direction %d\n", direction);
 936         dwc_desc_put(dwc, first);
 937         return NULL;
 938 }
 939
 940 bool dw_dma_filter(struct dma_chan *chan, void *param)
 941 {
 942         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 943         struct dw_dma_slave *dws = param;
 944
 945         if (!dws || dws->dma_dev != chan->device->dev)
 946                 return false;
 947
 948         /* We have to copy data since dws can be temporary storage */
 949
 950         dwc->src_id = dws->src_id;
 951         dwc->dst_id = dws->dst_id;
 952
 953         dwc->src_master = dws->src_master;
 954         dwc->dst_master = dws->dst_master;
 955
 956         return true;
 957 }
 958 EXPORT_SYMBOL_GPL(dw_dma_filter);
 959
 960 /*
 961  * Fix sconfig's burst size according to dw_dmac. We need to convert them as:
 962  * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
 963  *
 964  * NOTE: burst size 2 is not supported by controller.
 965  *
 966  * This can be done by finding least significant bit set: n & (n - 1)
 967  */
 968 static inline void convert_burst(u32 *maxburst)
 969 {
 970         if (*maxburst > 1)
 971                 *maxburst = fls(*maxburst) - 2;
 972         else
 973                 *maxburst = 0;
 974 }
 975
 976 static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
 977 {
 978         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 979
 980         /* Check if chan will be configured for slave transfers */
 981         if (!is_slave_direction(sconfig->direction))
 982                 return -EINVAL;
 983
 984         memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig));
 985         dwc->direction = sconfig->direction;
 986
 987         convert_burst(&dwc->dma_sconfig.src_maxburst);
 988         convert_burst(&dwc->dma_sconfig.dst_maxburst);
 989
 990         return 0;
 991 }
 992
 993 static int dwc_pause(struct dma_chan *chan)
 994 {
 995         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 996         unsigned long           flags;
 997         unsigned int            count = 20;     /* timeout iterations */
 998         u32                     cfglo;
 999
1000         spin_lock_irqsave(&dwc->lock, flags);
1001
1002         cfglo = channel_readl(dwc, CFG_LO);
1003         channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
1004         while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY) && count--)
1005                 udelay(2);
1006
1007         dwc->paused = true;
1008
1009         spin_unlock_irqrestore(&dwc->lock, flags);
1010
1011         return 0;
1012 }
1013
1014 static inline void dwc_chan_resume(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
1020         dwc->paused = false;
1021 }
1022
1023 static int dwc_resume(struct dma_chan *chan)
1024 {
1025         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1026         unsigned long           flags;
1027
1028         if (!dwc->paused)
1029                 return 0;
1030
1031         spin_lock_irqsave(&dwc->lock, flags);
1032
1033         dwc_chan_resume(dwc);
1034
1035         spin_unlock_irqrestore(&dwc->lock, flags);
1036
1037         return 0;
1038 }
1039
1040 static int dwc_terminate_all(struct dma_chan *chan)
1041 {
1042         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1043         struct dw_dma           *dw = to_dw_dma(chan->device);
1044         struct dw_desc          *desc, *_desc;
1045         unsigned long           flags;
1046         LIST_HEAD(list);
1047
1048         spin_lock_irqsave(&dwc->lock, flags);
1049
1050         clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
1051
1052         dwc_chan_disable(dw, dwc);
1053
1054         dwc_chan_resume(dwc);
1055
1056         /* active_list entries will end up before queued entries */
1057         list_splice_init(&dwc->queue, &list);
1058         list_splice_init(&dwc->active_list, &list);
1059
1060         spin_unlock_irqrestore(&dwc->lock, flags);
1061
1062         /* Flush all pending and queued descriptors */
1063         list_for_each_entry_safe(desc, _desc, &list, desc_node)
1064                 dwc_descriptor_complete(dwc, desc, false);
1065
1066         return 0;
1067 }
1068
1069 static inline u32 dwc_get_residue(struct dw_dma_chan *dwc)
1070 {
1071         unsigned long flags;
1072         u32 residue;
1073
1074         spin_lock_irqsave(&dwc->lock, flags);
1075
1076         residue = dwc->residue;
1077         if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags) && residue)
1078                 residue -= dwc_get_sent(dwc);
1079
1080         spin_unlock_irqrestore(&dwc->lock, flags);
1081         return residue;
1082 }
1083
1084 static enum dma_status
1085 dwc_tx_status(struct dma_chan *chan,
1086               dma_cookie_t cookie,
1087               struct dma_tx_state *txstate)
1088 {
1089         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1090         enum dma_status         ret;
1091
1092         ret = dma_cookie_status(chan, cookie, txstate);
1093         if (ret == DMA_COMPLETE)
1094                 return ret;
1095
1096         dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
1097
1098         ret = dma_cookie_status(chan, cookie, txstate);
1099         if (ret != DMA_COMPLETE)
1100                 dma_set_residue(txstate, dwc_get_residue(dwc));
1101
1102         if (dwc->paused && ret == DMA_IN_PROGRESS)
1103                 return DMA_PAUSED;
1104
1105         return ret;
1106 }
1107
1108 static void dwc_issue_pending(struct dma_chan *chan)
1109 {
1110         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1111         unsigned long           flags;
1112
1113         spin_lock_irqsave(&dwc->lock, flags);
1114         if (list_empty(&dwc->active_list))
1115                 dwc_dostart_first_queued(dwc);
1116         spin_unlock_irqrestore(&dwc->lock, flags);
1117 }
1118
1119 /*----------------------------------------------------------------------*/
1120
1121 static void dw_dma_off(struct dw_dma *dw)
1122 {
1123         int i;
1124
1125         dma_writel(dw, CFG, 0);
1126
1127         channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1128         channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1129         channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1130         channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1131         channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1132
1133         while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
1134                 cpu_relax();
1135
1136         for (i = 0; i < dw->dma.chancnt; i++)
1137                 dw->chan[i].initialized = false;
1138 }
1139
1140 static void dw_dma_on(struct dw_dma *dw)
1141 {
1142         dma_writel(dw, CFG, DW_CFG_DMA_EN);
1143 }
1144
1145 static int dwc_alloc_chan_resources(struct dma_chan *chan)
1146 {
1147         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1148         struct dw_dma           *dw = to_dw_dma(chan->device);
1149         struct dw_desc          *desc;
1150         int                     i;
1151         unsigned long           flags;
1152
1153         dev_vdbg(chan2dev(chan), "%s\n", __func__);
1154
1155         /* ASSERT:  channel is idle */
1156         if (dma_readl(dw, CH_EN) & dwc->mask) {
1157                 dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
1158                 return -EIO;
1159         }
1160
1161         dma_cookie_init(chan);
1162
1163         /*
1164          * NOTE: some controllers may have additional features that we
1165          * need to initialize here, like "scatter-gather" (which
1166          * doesn't mean what you think it means), and status writeback.
1167          */
1168
1169         /* Enable controller here if needed */
1170         if (!dw->in_use)
1171                 dw_dma_on(dw);
1172         dw->in_use |= dwc->mask;
1173
1174         spin_lock_irqsave(&dwc->lock, flags);
1175         i = dwc->descs_allocated;
1176         while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) {
1177                 dma_addr_t phys;
1178
1179                 spin_unlock_irqrestore(&dwc->lock, flags);
1180
1181                 desc = dma_pool_alloc(dw->desc_pool, GFP_ATOMIC, &phys);
1182                 if (!desc)
1183                         goto err_desc_alloc;
1184
1185                 memset(desc, 0, sizeof(struct dw_desc));
1186
1187                 INIT_LIST_HEAD(&desc->tx_list);
1188                 dma_async_tx_descriptor_init(&desc->txd, chan);
1189                 desc->txd.tx_submit = dwc_tx_submit;
1190                 desc->txd.flags = DMA_CTRL_ACK;
1191                 desc->txd.phys = phys;
1192
1193                 dwc_desc_put(dwc, desc);
1194
1195                 spin_lock_irqsave(&dwc->lock, flags);
1196                 i = ++dwc->descs_allocated;
1197         }
1198
1199         spin_unlock_irqrestore(&dwc->lock, flags);
1200
1201         dev_dbg(chan2dev(chan), "%s: allocated %d descriptors\n", __func__, i);
1202
1203         return i;
1204
1205 err_desc_alloc:
1206         dev_info(chan2dev(chan), "only allocated %d descriptors\n", i);
1207
1208         return i;
1209 }
1210
1211 static void dwc_free_chan_resources(struct dma_chan *chan)
1212 {
1213         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1214         struct dw_dma           *dw = to_dw_dma(chan->device);
1215         struct dw_desc          *desc, *_desc;
1216         unsigned long           flags;
1217         LIST_HEAD(list);
1218
1219         dev_dbg(chan2dev(chan), "%s: descs allocated=%u\n", __func__,
1220                         dwc->descs_allocated);
1221
1222         /* ASSERT:  channel is idle */
1223         BUG_ON(!list_empty(&dwc->active_list));
1224         BUG_ON(!list_empty(&dwc->queue));
1225         BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
1226
1227         spin_lock_irqsave(&dwc->lock, flags);
1228         list_splice_init(&dwc->free_list, &list);
1229         dwc->descs_allocated = 0;
1230         dwc->initialized = false;
1231
1232         /* Disable interrupts */
1233         channel_clear_bit(dw, MASK.XFER, dwc->mask);
1234         channel_clear_bit(dw, MASK.BLOCK, dwc->mask);
1235         channel_clear_bit(dw, MASK.ERROR, dwc->mask);
1236
1237         spin_unlock_irqrestore(&dwc->lock, flags);
1238
1239         /* Disable controller in case it was a last user */
1240         dw->in_use &= ~dwc->mask;
1241         if (!dw->in_use)
1242                 dw_dma_off(dw);
1243
1244         list_for_each_entry_safe(desc, _desc, &list, desc_node) {
1245                 dev_vdbg(chan2dev(chan), "  freeing descriptor %p\n", desc);
1246                 dma_pool_free(dw->desc_pool, desc, desc->txd.phys);
1247         }
1248
1249         dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
1250 }
1251
1252 /* --------------------- Cyclic DMA API extensions -------------------- */
1253
1254 /**
1255  * dw_dma_cyclic_start - start the cyclic DMA transfer
1256  * @chan: the DMA channel to start
1257  *
1258  * Must be called with soft interrupts disabled. Returns zero on success or
1259  * -errno on failure.
1260  */
1261 int dw_dma_cyclic_start(struct dma_chan *chan)
1262 {
1263         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1264         unsigned long           flags;
1265
1266         if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
1267                 dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n");
1268                 return -ENODEV;
1269         }
1270
1271         spin_lock_irqsave(&dwc->lock, flags);
1272         dwc_dostart(dwc, dwc->cdesc->desc[0]);
1273         spin_unlock_irqrestore(&dwc->lock, flags);
1274
1275         return 0;
1276 }
1277 EXPORT_SYMBOL(dw_dma_cyclic_start);
1278
1279 /**
1280  * dw_dma_cyclic_stop - stop the cyclic DMA transfer
1281  * @chan: the DMA channel to stop
1282  *
1283  * Must be called with soft interrupts disabled.
1284  */
1285 void dw_dma_cyclic_stop(struct dma_chan *chan)
1286 {
1287         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1288         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
1289         unsigned long           flags;
1290
1291         spin_lock_irqsave(&dwc->lock, flags);
1292
1293         dwc_chan_disable(dw, dwc);
1294
1295         spin_unlock_irqrestore(&dwc->lock, flags);
1296 }
1297 EXPORT_SYMBOL(dw_dma_cyclic_stop);
1298
1299 /**
1300  * dw_dma_cyclic_prep - prepare the cyclic DMA transfer
1301  * @chan: the DMA channel to prepare
1302  * @buf_addr: physical DMA address where the buffer starts
1303  * @buf_len: total number of bytes for the entire buffer
1304  * @period_len: number of bytes for each period
1305  * @direction: transfer direction, to or from device
1306  *
1307  * Must be called before trying to start the transfer. Returns a valid struct
1308  * dw_cyclic_desc if successful or an ERR_PTR(-errno) if not successful.
1309  */
1310 struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
1311                 dma_addr_t buf_addr, size_t buf_len, size_t period_len,
1312                 enum dma_transfer_direction direction)
1313 {
1314         struct dw_dma_chan              *dwc = to_dw_dma_chan(chan);
1315         struct dma_slave_config         *sconfig = &dwc->dma_sconfig;
1316         struct dw_cyclic_desc           *cdesc;
1317         struct dw_cyclic_desc           *retval = NULL;
1318         struct dw_desc                  *desc;
1319         struct dw_desc                  *last = NULL;
1320         unsigned long                   was_cyclic;
1321         unsigned int                    reg_width;
1322         unsigned int                    periods;
1323         unsigned int                    i;
1324         unsigned long                   flags;
1325
1326         spin_lock_irqsave(&dwc->lock, flags);
1327         if (dwc->nollp) {
1328                 spin_unlock_irqrestore(&dwc->lock, flags);
1329                 dev_dbg(chan2dev(&dwc->chan),
1330                                 "channel doesn't support LLP transfers\n");
1331                 return ERR_PTR(-EINVAL);
1332         }
1333
1334         if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) {
1335                 spin_unlock_irqrestore(&dwc->lock, flags);
1336                 dev_dbg(chan2dev(&dwc->chan),
1337                                 "queue and/or active list are not empty\n");
1338                 return ERR_PTR(-EBUSY);
1339         }
1340
1341         was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1342         spin_unlock_irqrestore(&dwc->lock, flags);
1343         if (was_cyclic) {
1344                 dev_dbg(chan2dev(&dwc->chan),
1345                                 "channel already prepared for cyclic DMA\n");
1346                 return ERR_PTR(-EBUSY);
1347         }
1348
1349         retval = ERR_PTR(-EINVAL);
1350
1351         if (unlikely(!is_slave_direction(direction)))
1352                 goto out_err;
1353
1354         dwc->direction = direction;
1355
1356         if (direction == DMA_MEM_TO_DEV)
1357                 reg_width = __ffs(sconfig->dst_addr_width);
1358         else
1359                 reg_width = __ffs(sconfig->src_addr_width);
1360
1361         periods = buf_len / period_len;
1362
1363         /* Check for too big/unaligned periods and unaligned DMA buffer. */
1364         if (period_len > (dwc->block_size << reg_width))
1365                 goto out_err;
1366         if (unlikely(period_len & ((1 << reg_width) - 1)))
1367                 goto out_err;
1368         if (unlikely(buf_addr & ((1 << reg_width) - 1)))
1369                 goto out_err;
1370
1371         retval = ERR_PTR(-ENOMEM);
1372
1373         if (periods > NR_DESCS_PER_CHANNEL)
1374                 goto out_err;
1375
1376         cdesc = kzalloc(sizeof(struct dw_cyclic_desc), GFP_KERNEL);
1377         if (!cdesc)
1378                 goto out_err;
1379
1380         cdesc->desc = kzalloc(sizeof(struct dw_desc *) * periods, GFP_KERNEL);
1381         if (!cdesc->desc)
1382                 goto out_err_alloc;
1383
1384         for (i = 0; i < periods; i++) {
1385                 desc = dwc_desc_get(dwc);
1386                 if (!desc)
1387                         goto out_err_desc_get;
1388
1389                 switch (direction) {
1390                 case DMA_MEM_TO_DEV:
1391                         desc->lli.dar = sconfig->dst_addr;
1392                         desc->lli.sar = buf_addr + (period_len * i);
1393                         desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan)
1394                                         | DWC_CTLL_DST_WIDTH(reg_width)
1395                                         | DWC_CTLL_SRC_WIDTH(reg_width)
1396                                         | DWC_CTLL_DST_FIX
1397                                         | DWC_CTLL_SRC_INC
1398                                         | DWC_CTLL_INT_EN);
1399
1400                         desc->lli.ctllo |= sconfig->device_fc ?
1401                                 DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
1402                                 DWC_CTLL_FC(DW_DMA_FC_D_M2P);
1403
1404                         break;
1405                 case DMA_DEV_TO_MEM:
1406                         desc->lli.dar = buf_addr + (period_len * i);
1407                         desc->lli.sar = sconfig->src_addr;
1408                         desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan)
1409                                         | DWC_CTLL_SRC_WIDTH(reg_width)
1410                                         | DWC_CTLL_DST_WIDTH(reg_width)
1411                                         | DWC_CTLL_DST_INC
1412                                         | DWC_CTLL_SRC_FIX
1413                                         | DWC_CTLL_INT_EN);
1414
1415                         desc->lli.ctllo |= sconfig->device_fc ?
1416                                 DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
1417                                 DWC_CTLL_FC(DW_DMA_FC_D_P2M);
1418
1419                         break;
1420                 default:
1421                         break;
1422                 }
1423
1424                 desc->lli.ctlhi = (period_len >> reg_width);
1425                 cdesc->desc[i] = desc;
1426
1427                 if (last)
1428                         last->lli.llp = desc->txd.phys;
1429
1430                 last = desc;
1431         }
1432
1433         /* Let's make a cyclic list */
1434         last->lli.llp = cdesc->desc[0]->txd.phys;
1435
1436         dev_dbg(chan2dev(&dwc->chan),
1437                         "cyclic prepared buf %pad len %zu period %zu periods %d\n",
1438                         &buf_addr, buf_len, period_len, periods);
1439
1440         cdesc->periods = periods;
1441         dwc->cdesc = cdesc;
1442
1443         return cdesc;
1444
1445 out_err_desc_get:
1446         while (i--)
1447                 dwc_desc_put(dwc, cdesc->desc[i]);
1448 out_err_alloc:
1449         kfree(cdesc);
1450 out_err:
1451         clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1452         return (struct dw_cyclic_desc *)retval;
1453 }
1454 EXPORT_SYMBOL(dw_dma_cyclic_prep);
1455
1456 /**
1457  * dw_dma_cyclic_free - free a prepared cyclic DMA transfer
1458  * @chan: the DMA channel to free
1459  */
1460 void dw_dma_cyclic_free(struct dma_chan *chan)
1461 {
1462         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1463         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
1464         struct dw_cyclic_desc   *cdesc = dwc->cdesc;
1465         int                     i;
1466         unsigned long           flags;
1467
1468         dev_dbg(chan2dev(&dwc->chan), "%s\n", __func__);
1469
1470         if (!cdesc)
1471                 return;
1472
1473         spin_lock_irqsave(&dwc->lock, flags);
1474
1475         dwc_chan_disable(dw, dwc);
1476
1477         dma_writel(dw, CLEAR.BLOCK, dwc->mask);
1478         dma_writel(dw, CLEAR.ERROR, dwc->mask);
1479         dma_writel(dw, CLEAR.XFER, dwc->mask);
1480
1481         spin_unlock_irqrestore(&dwc->lock, flags);
1482
1483         for (i = 0; i < cdesc->periods; i++)
1484                 dwc_desc_put(dwc, cdesc->desc[i]);
1485
1486         kfree(cdesc->desc);
1487         kfree(cdesc);
1488
1489         clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1490 }
1491 EXPORT_SYMBOL(dw_dma_cyclic_free);
1492
1493 /*----------------------------------------------------------------------*/
1494
1495 int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
1496 {
1497         struct dw_dma           *dw;
1498         bool                    autocfg = false;
1499         unsigned int            dw_params;
1500         unsigned int            max_blk_size = 0;
1501         int                     err;
1502         int                     i;
1503
1504         dw = devm_kzalloc(chip->dev, sizeof(*dw), GFP_KERNEL);
1505         if (!dw)
1506                 return -ENOMEM;
1507
1508         dw->regs = chip->regs;
1509         chip->dw = dw;
1510
1511         pm_runtime_get_sync(chip->dev);
1512
1513         if (!pdata) {
1514                 dw_params = dma_read_byaddr(chip->regs, DW_PARAMS);
1515                 dev_dbg(chip->dev, "DW_PARAMS: 0x%08x\n", dw_params);
1516
1517                 autocfg = dw_params >> DW_PARAMS_EN & 1;
1518                 if (!autocfg) {
1519                         err = -EINVAL;
1520                         goto err_pdata;
1521                 }
1522
1523                 pdata = devm_kzalloc(chip->dev, sizeof(*pdata), GFP_KERNEL);
1524                 if (!pdata) {
1525                         err = -ENOMEM;
1526                         goto err_pdata;
1527                 }
1528
1529                 /* Get hardware configuration parameters */
1530                 pdata->nr_channels = (dw_params >> DW_PARAMS_NR_CHAN & 7) + 1;
1531                 pdata->nr_masters = (dw_params >> DW_PARAMS_NR_MASTER & 3) + 1;
1532                 for (i = 0; i < pdata->nr_masters; i++) {
1533                         pdata->data_width[i] =
1534                                 (dw_params >> DW_PARAMS_DATA_WIDTH(i) & 3) + 2;
1535                 }
1536                 max_blk_size = dma_readl(dw, MAX_BLK_SIZE);
1537
1538                 /* Fill platform data with the default values */
1539                 pdata->is_private = true;
1540                 pdata->is_memcpy = true;
1541                 pdata->chan_allocation_order = CHAN_ALLOCATION_ASCENDING;
1542                 pdata->chan_priority = CHAN_PRIORITY_ASCENDING;
1543         } else if (pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS) {
1544                 err = -EINVAL;
1545                 goto err_pdata;
1546         }
1547
1548         dw->chan = devm_kcalloc(chip->dev, pdata->nr_channels, sizeof(*dw->chan),
1549                                 GFP_KERNEL);
1550         if (!dw->chan) {
1551                 err = -ENOMEM;
1552                 goto err_pdata;
1553         }
1554
1555         /* Get hardware configuration parameters */
1556         dw->nr_masters = pdata->nr_masters;
1557         for (i = 0; i < dw->nr_masters; i++)
1558                 dw->data_width[i] = pdata->data_width[i];
1559
1560         /* Calculate all channel mask before DMA setup */
1561         dw->all_chan_mask = (1 << pdata->nr_channels) - 1;
1562
1563         /* Force dma off, just in case */
1564         dw_dma_off(dw);
1565
1566         /* Create a pool of consistent memory blocks for hardware descriptors */
1567         dw->desc_pool = dmam_pool_create("dw_dmac_desc_pool", chip->dev,
1568                                          sizeof(struct dw_desc), 4, 0);
1569         if (!dw->desc_pool) {
1570                 dev_err(chip->dev, "No memory for descriptors dma pool\n");
1571                 err = -ENOMEM;
1572                 goto err_pdata;
1573         }
1574
1575         tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
1576
1577         err = request_irq(chip->irq, dw_dma_interrupt, IRQF_SHARED,
1578                           "dw_dmac", dw);
1579         if (err)
1580                 goto err_pdata;
1581
1582         INIT_LIST_HEAD(&dw->dma.channels);
1583         for (i = 0; i < pdata->nr_channels; i++) {
1584                 struct dw_dma_chan      *dwc = &dw->chan[i];
1585
1586                 dwc->chan.device = &dw->dma;
1587                 dma_cookie_init(&dwc->chan);
1588                 if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING)
1589                         list_add_tail(&dwc->chan.device_node,
1590                                         &dw->dma.channels);
1591                 else
1592                         list_add(&dwc->chan.device_node, &dw->dma.channels);
1593
1594                 /* 7 is highest priority & 0 is lowest. */
1595                 if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING)
1596                         dwc->priority = pdata->nr_channels - i - 1;
1597                 else
1598                         dwc->priority = i;
1599
1600                 dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
1601                 spin_lock_init(&dwc->lock);
1602                 dwc->mask = 1 << i;
1603
1604                 INIT_LIST_HEAD(&dwc->active_list);
1605                 INIT_LIST_HEAD(&dwc->queue);
1606                 INIT_LIST_HEAD(&dwc->free_list);
1607
1608                 channel_clear_bit(dw, CH_EN, dwc->mask);
1609
1610                 dwc->direction = DMA_TRANS_NONE;
1611
1612                 /* Hardware configuration */
1613                 if (autocfg) {
1614                         unsigned int dwc_params;
1615                         unsigned int r = DW_DMA_MAX_NR_CHANNELS - i - 1;
1616                         void __iomem *addr = chip->regs + r * sizeof(u32);
1617
1618                         dwc_params = dma_read_byaddr(addr, DWC_PARAMS);
1619
1620                         dev_dbg(chip->dev, "DWC_PARAMS[%d]: 0x%08x\n", i,
1621                                            dwc_params);
1622
1623                         /*
1624                          * Decode maximum block size for given channel. The
1625                          * stored 4 bit value represents blocks from 0x00 for 3
1626                          * up to 0x0a for 4095.
1627                          */
1628                         dwc->block_size =
1629                                 (4 << ((max_blk_size >> 4 * i) & 0xf)) - 1;
1630                         dwc->nollp =
1631                                 (dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0;
1632                 } else {
1633                         dwc->block_size = pdata->block_size;
1634
1635                         /* Check if channel supports multi block transfer */
1636                         channel_writel(dwc, LLP, 0xfffffffc);
1637                         dwc->nollp =
1638                                 (channel_readl(dwc, LLP) & 0xfffffffc) == 0;
1639                         channel_writel(dwc, LLP, 0);
1640                 }
1641         }
1642
1643         /* Clear all interrupts on all channels. */
1644         dma_writel(dw, CLEAR.XFER, dw->all_chan_mask);
1645         dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask);
1646         dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask);
1647         dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask);
1648         dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask);
1649
1650         /* Set capabilities */
1651         dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
1652         if (pdata->is_private)
1653                 dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask);
1654         if (pdata->is_memcpy)
1655                 dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
1656
1657         dw->dma.dev = chip->dev;
1658         dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
1659         dw->dma.device_free_chan_resources = dwc_free_chan_resources;
1660
1661         dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
1662         dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
1663
1664         dw->dma.device_config = dwc_config;
1665         dw->dma.device_pause = dwc_pause;
1666         dw->dma.device_resume = dwc_resume;
1667         dw->dma.device_terminate_all = dwc_terminate_all;
1668
1669         dw->dma.device_tx_status = dwc_tx_status;
1670         dw->dma.device_issue_pending = dwc_issue_pending;
1671
1672         /* DMA capabilities */
1673         dw->dma.src_addr_widths = DW_DMA_BUSWIDTHS;
1674         dw->dma.dst_addr_widths = DW_DMA_BUSWIDTHS;
1675         dw->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
1676                              BIT(DMA_MEM_TO_MEM);
1677         dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1678
1679         err = dma_async_device_register(&dw->dma);
1680         if (err)
1681                 goto err_dma_register;
1682
1683         dev_info(chip->dev, "DesignWare DMA Controller, %d channels\n",
1684                  pdata->nr_channels);
1685
1686         pm_runtime_put_sync_suspend(chip->dev);
1687
1688         return 0;
1689
1690 err_dma_register:
1691         free_irq(chip->irq, dw);
1692 err_pdata:
1693         pm_runtime_put_sync_suspend(chip->dev);
1694         return err;
1695 }
1696 EXPORT_SYMBOL_GPL(dw_dma_probe);
1697
1698 int dw_dma_remove(struct dw_dma_chip *chip)
1699 {
1700         struct dw_dma           *dw = chip->dw;
1701         struct dw_dma_chan      *dwc, *_dwc;
1702
1703         pm_runtime_get_sync(chip->dev);
1704
1705         dw_dma_off(dw);
1706         dma_async_device_unregister(&dw->dma);
1707
1708         free_irq(chip->irq, dw);
1709         tasklet_kill(&dw->tasklet);
1710
1711         list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,
1712                         chan.device_node) {
1713                 list_del(&dwc->chan.device_node);
1714                 channel_clear_bit(dw, CH_EN, dwc->mask);
1715         }
1716
1717         pm_runtime_put_sync_suspend(chip->dev);
1718         return 0;
1719 }
1720 EXPORT_SYMBOL_GPL(dw_dma_remove);
1721
1722 int dw_dma_disable(struct dw_dma_chip *chip)
1723 {
1724         struct dw_dma *dw = chip->dw;
1725
1726         dw_dma_off(dw);
1727         return 0;
1728 }
1729 EXPORT_SYMBOL_GPL(dw_dma_disable);
1730
1731 int dw_dma_enable(struct dw_dma_chip *chip)
1732 {
1733         struct dw_dma *dw = chip->dw;
1734
1735         dw_dma_on(dw);
1736         return 0;
1737 }
1738 EXPORT_SYMBOL_GPL(dw_dma_enable);
1739
1740 MODULE_LICENSE("GPL v2");
1741 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller core driver");
1742 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
1743 MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");