drivers/dma/dw_dmac.c

   1 /*
   2  * Driver for the Synopsys DesignWare DMA Controller (aka DMACA on
   3  * AVR32 systems.)
   4  *
   5  * Copyright (C) 2007-2008 Atmel Corporation
   6  * Copyright (C) 2010-2011 ST Microelectronics
   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 #include <linux/clk.h>
  13 #include <linux/delay.h>
  14 #include <linux/dmaengine.h>
  15 #include <linux/dma-mapping.h>
  16 #include <linux/init.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/io.h>
  19 #include <linux/mm.h>
  20 #include <linux/module.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/slab.h>
  23
  24 #include "dw_dmac_regs.h"
  25
  26 /*
  27  * This supports the Synopsys "DesignWare AHB Central DMA Controller",
  28  * (DW_ahb_dmac) which is used with various AMBA 2.0 systems (not all
  29  * of which use ARM any more).  See the "Databook" from Synopsys for
  30  * information beyond what licensees probably provide.
  31  *
  32  * The driver has currently been tested only with the Atmel AT32AP7000,
  33  * which does not support descriptor writeback.
  34  */
  35
  36 #define DWC_DEFAULT_CTLLO(private) ({                           \
  37                 struct dw_dma_slave *__slave = (private);       \
  38                 int dms = __slave ? __slave->dst_master : 0;    \
  39                 int sms = __slave ? __slave->src_master : 1;    \
  40                 u8 smsize = __slave ? __slave->src_msize : DW_DMA_MSIZE_16; \
  41                 u8 dmsize = __slave ? __slave->dst_msize : DW_DMA_MSIZE_16; \
  42                                                                 \
  43                 (DWC_CTLL_DST_MSIZE(dmsize)                     \
  44                  | DWC_CTLL_SRC_MSIZE(smsize)                   \
  45                  | DWC_CTLL_LLP_D_EN                            \
  46                  | DWC_CTLL_LLP_S_EN                            \
  47                  | DWC_CTLL_DMS(dms)                            \
  48                  | DWC_CTLL_SMS(sms));                          \
  49         })
  50
  51 /*
  52  * This is configuration-dependent and usually a funny size like 4095.
  53  *
  54  * Note that this is a transfer count, i.e. if we transfer 32-bit
  55  * words, we can do 16380 bytes per descriptor.
  56  *
  57  * This parameter is also system-specific.
  58  */
  59 #define DWC_MAX_COUNT   4095U
  60
  61 /*
  62  * Number of descriptors to allocate for each channel. This should be
  63  * made configurable somehow; preferably, the clients (at least the
  64  * ones using slave transfers) should be able to give us a hint.
  65  */
  66 #define NR_DESCS_PER_CHANNEL    64
  67
  68 /*----------------------------------------------------------------------*/
  69
  70 /*
  71  * Because we're not relying on writeback from the controller (it may not
  72  * even be configured into the core!) we don't need to use dma_pool.  These
  73  * descriptors -- and associated data -- are cacheable.  We do need to make
  74  * sure their dcache entries are written back before handing them off to
  75  * the controller, though.
  76  */
  77
  78 static struct device *chan2dev(struct dma_chan *chan)
  79 {
  80         return &chan->dev->device;
  81 }
  82 static struct device *chan2parent(struct dma_chan *chan)
  83 {
  84         return chan->dev->device.parent;
  85 }
  86
  87 static struct dw_desc *dwc_first_active(struct dw_dma_chan *dwc)
  88 {
  89         return list_entry(dwc->active_list.next, struct dw_desc, desc_node);
  90 }
  91
  92 static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc)
  93 {
  94         struct dw_desc *desc, *_desc;
  95         struct dw_desc *ret = NULL;
  96         unsigned int i = 0;
  97         unsigned long flags;
  98
  99         spin_lock_irqsave(&dwc->lock, flags);
 100         list_for_each_entry_safe(desc, _desc, &dwc->free_list, desc_node) {
 101                 if (async_tx_test_ack(&desc->txd)) {
 102                         list_del(&desc->desc_node);
 103                         ret = desc;
 104                         break;
 105                 }
 106                 dev_dbg(chan2dev(&dwc->chan), "desc %p not ACKed\n", desc);
 107                 i++;
 108         }
 109         spin_unlock_irqrestore(&dwc->lock, flags);
 110
 111         dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i);
 112
 113         return ret;
 114 }
 115
 116 static void dwc_sync_desc_for_cpu(struct dw_dma_chan *dwc, struct dw_desc *desc)
 117 {
 118         struct dw_desc  *child;
 119
 120         list_for_each_entry(child, &desc->tx_list, desc_node)
 121                 dma_sync_single_for_cpu(chan2parent(&dwc->chan),
 122                                 child->txd.phys, sizeof(child->lli),
 123                                 DMA_TO_DEVICE);
 124         dma_sync_single_for_cpu(chan2parent(&dwc->chan),
 125                         desc->txd.phys, sizeof(desc->lli),
 126                         DMA_TO_DEVICE);
 127 }
 128
 129 /*
 130  * Move a descriptor, including any children, to the free list.
 131  * `desc' must not be on any lists.
 132  */
 133 static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
 134 {
 135         unsigned long flags;
 136
 137         if (desc) {
 138                 struct dw_desc *child;
 139
 140                 dwc_sync_desc_for_cpu(dwc, desc);
 141
 142                 spin_lock_irqsave(&dwc->lock, flags);
 143                 list_for_each_entry(child, &desc->tx_list, desc_node)
 144                         dev_vdbg(chan2dev(&dwc->chan),
 145                                         "moving child desc %p to freelist\n",
 146                                         child);
 147                 list_splice_init(&desc->tx_list, &dwc->free_list);
 148                 dev_vdbg(chan2dev(&dwc->chan), "moving desc %p to freelist\n", desc);
 149                 list_add(&desc->desc_node, &dwc->free_list);
 150                 spin_unlock_irqrestore(&dwc->lock, flags);
 151         }
 152 }
 153
 154 /* Called with dwc->lock held and bh disabled */
 155 static dma_cookie_t
 156 dwc_assign_cookie(struct dw_dma_chan *dwc, struct dw_desc *desc)
 157 {
 158         dma_cookie_t cookie = dwc->chan.cookie;
 159
 160         if (++cookie < 0)
 161                 cookie = 1;
 162
 163         dwc->chan.cookie = cookie;
 164         desc->txd.cookie = cookie;
 165
 166         return cookie;
 167 }
 168
 169 /*----------------------------------------------------------------------*/
 170
 171 /* Called with dwc->lock held and bh disabled */
 172 static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
 173 {
 174         struct dw_dma   *dw = to_dw_dma(dwc->chan.device);
 175
 176         /* ASSERT:  channel is idle */
 177         if (dma_readl(dw, CH_EN) & dwc->mask) {
 178                 dev_err(chan2dev(&dwc->chan),
 179                         "BUG: Attempted to start non-idle channel\n");
 180                 dev_err(chan2dev(&dwc->chan),
 181                         "  SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
 182                         channel_readl(dwc, SAR),
 183                         channel_readl(dwc, DAR),
 184                         channel_readl(dwc, LLP),
 185                         channel_readl(dwc, CTL_HI),
 186                         channel_readl(dwc, CTL_LO));
 187
 188                 /* The tasklet will hopefully advance the queue... */
 189                 return;
 190         }
 191
 192         channel_writel(dwc, LLP, first->txd.phys);
 193         channel_writel(dwc, CTL_LO,
 194                         DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
 195         channel_writel(dwc, CTL_HI, 0);
 196         channel_set_bit(dw, CH_EN, dwc->mask);
 197 }
 198
 199 /*----------------------------------------------------------------------*/
 200
 201 static void
 202 dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc,
 203                 bool callback_required)
 204 {
 205         dma_async_tx_callback           callback = NULL;
 206         void                            *param = NULL;
 207         struct dma_async_tx_descriptor  *txd = &desc->txd;
 208         struct dw_desc                  *child;
 209         unsigned long                   flags;
 210
 211         dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
 212
 213         spin_lock_irqsave(&dwc->lock, flags);
 214         dwc->completed = txd->cookie;
 215         if (callback_required) {
 216                 callback = txd->callback;
 217                 param = txd->callback_param;
 218         }
 219
 220         dwc_sync_desc_for_cpu(dwc, desc);
 221
 222         /* async_tx_ack */
 223         list_for_each_entry(child, &desc->tx_list, desc_node)
 224                 async_tx_ack(&child->txd);
 225         async_tx_ack(&desc->txd);
 226
 227         list_splice_init(&desc->tx_list, &dwc->free_list);
 228         list_move(&desc->desc_node, &dwc->free_list);
 229
 230         if (!dwc->chan.private) {
 231                 struct device *parent = chan2parent(&dwc->chan);
 232                 if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
 233                         if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
 234                                 dma_unmap_single(parent, desc->lli.dar,
 235                                                 desc->len, DMA_FROM_DEVICE);
 236                         else
 237                                 dma_unmap_page(parent, desc->lli.dar,
 238                                                 desc->len, DMA_FROM_DEVICE);
 239                 }
 240                 if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
 241                         if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
 242                                 dma_unmap_single(parent, desc->lli.sar,
 243                                                 desc->len, DMA_TO_DEVICE);
 244                         else
 245                                 dma_unmap_page(parent, desc->lli.sar,
 246                                                 desc->len, DMA_TO_DEVICE);
 247                 }
 248         }
 249
 250         spin_unlock_irqrestore(&dwc->lock, flags);
 251
 252         if (callback_required && callback)
 253                 callback(param);
 254 }
 255
 256 static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
 257 {
 258         struct dw_desc *desc, *_desc;
 259         LIST_HEAD(list);
 260         unsigned long flags;
 261
 262         spin_lock_irqsave(&dwc->lock, flags);
 263         if (dma_readl(dw, CH_EN) & dwc->mask) {
 264                 dev_err(chan2dev(&dwc->chan),
 265                         "BUG: XFER bit set, but channel not idle!\n");
 266
 267                 /* Try to continue after resetting the channel... */
 268                 channel_clear_bit(dw, CH_EN, dwc->mask);
 269                 while (dma_readl(dw, CH_EN) & dwc->mask)
 270                         cpu_relax();
 271         }
 272
 273         /*
 274          * Submit queued descriptors ASAP, i.e. before we go through
 275          * the completed ones.
 276          */
 277         list_splice_init(&dwc->active_list, &list);
 278         if (!list_empty(&dwc->queue)) {
 279                 list_move(dwc->queue.next, &dwc->active_list);
 280                 dwc_dostart(dwc, dwc_first_active(dwc));
 281         }
 282
 283         spin_unlock_irqrestore(&dwc->lock, flags);
 284
 285         list_for_each_entry_safe(desc, _desc, &list, desc_node)
 286                 dwc_descriptor_complete(dwc, desc, true);
 287 }
 288
 289 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
 290 {
 291         dma_addr_t llp;
 292         struct dw_desc *desc, *_desc;
 293         struct dw_desc *child;
 294         u32 status_xfer;
 295         unsigned long flags;
 296
 297         spin_lock_irqsave(&dwc->lock, flags);
 298         /*
 299          * Clear block interrupt flag before scanning so that we don't
 300          * miss any, and read LLP before RAW_XFER to ensure it is
 301          * valid if we decide to scan the list.
 302          */
 303         dma_writel(dw, CLEAR.BLOCK, dwc->mask);
 304         llp = channel_readl(dwc, LLP);
 305         status_xfer = dma_readl(dw, RAW.XFER);
 306
 307         if (status_xfer & dwc->mask) {
 308                 /* Everything we've submitted is done */
 309                 dma_writel(dw, CLEAR.XFER, dwc->mask);
 310                 spin_unlock_irqrestore(&dwc->lock, flags);
 311
 312                 dwc_complete_all(dw, dwc);
 313                 return;
 314         }
 315
 316         if (list_empty(&dwc->active_list)) {
 317                 spin_unlock_irqrestore(&dwc->lock, flags);
 318                 return;
 319         }
 320
 321         dev_vdbg(chan2dev(&dwc->chan), "scan_descriptors: llp=0x%x\n", llp);
 322
 323         list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
 324                 /* check first descriptors addr */
 325                 if (desc->txd.phys == llp) {
 326                         spin_unlock_irqrestore(&dwc->lock, flags);
 327                         return;
 328                 }
 329
 330                 /* check first descriptors llp */
 331                 if (desc->lli.llp == llp) {
 332                         /* This one is currently in progress */
 333                         spin_unlock_irqrestore(&dwc->lock, flags);
 334                         return;
 335                 }
 336
 337                 list_for_each_entry(child, &desc->tx_list, desc_node)
 338                         if (child->lli.llp == llp) {
 339                                 /* Currently in progress */
 340                                 spin_unlock_irqrestore(&dwc->lock, flags);
 341                                 return;
 342                         }
 343
 344                 /*
 345                  * No descriptors so far seem to be in progress, i.e.
 346                  * this one must be done.
 347                  */
 348                 spin_unlock_irqrestore(&dwc->lock, flags);
 349                 dwc_descriptor_complete(dwc, desc, true);
 350                 spin_lock_irqsave(&dwc->lock, flags);
 351         }
 352
 353         dev_err(chan2dev(&dwc->chan),
 354                 "BUG: All descriptors done, but channel not idle!\n");
 355
 356         /* Try to continue after resetting the channel... */
 357         channel_clear_bit(dw, CH_EN, dwc->mask);
 358         while (dma_readl(dw, CH_EN) & dwc->mask)
 359                 cpu_relax();
 360
 361         if (!list_empty(&dwc->queue)) {
 362                 list_move(dwc->queue.next, &dwc->active_list);
 363                 dwc_dostart(dwc, dwc_first_active(dwc));
 364         }
 365         spin_unlock_irqrestore(&dwc->lock, flags);
 366 }
 367
 368 static void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli)
 369 {
 370         dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
 371                         "  desc: s0x%x d0x%x l0x%x c0x%x:%x\n",
 372                         lli->sar, lli->dar, lli->llp,
 373                         lli->ctlhi, lli->ctllo);
 374 }
 375
 376 static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
 377 {
 378         struct dw_desc *bad_desc;
 379         struct dw_desc *child;
 380         unsigned long flags;
 381
 382         dwc_scan_descriptors(dw, dwc);
 383
 384         spin_lock_irqsave(&dwc->lock, flags);
 385
 386         /*
 387          * The descriptor currently at the head of the active list is
 388          * borked. Since we don't have any way to report errors, we'll
 389          * just have to scream loudly and try to carry on.
 390          */
 391         bad_desc = dwc_first_active(dwc);
 392         list_del_init(&bad_desc->desc_node);
 393         list_move(dwc->queue.next, dwc->active_list.prev);
 394
 395         /* Clear the error flag and try to restart the controller */
 396         dma_writel(dw, CLEAR.ERROR, dwc->mask);
 397         if (!list_empty(&dwc->active_list))
 398                 dwc_dostart(dwc, dwc_first_active(dwc));
 399
 400         /*
 401          * KERN_CRITICAL may seem harsh, but since this only happens
 402          * when someone submits a bad physical address in a
 403          * descriptor, we should consider ourselves lucky that the
 404          * controller flagged an error instead of scribbling over
 405          * random memory locations.
 406          */
 407         dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
 408                         "Bad descriptor submitted for DMA!\n");
 409         dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
 410                         "  cookie: %d\n", bad_desc->txd.cookie);
 411         dwc_dump_lli(dwc, &bad_desc->lli);
 412         list_for_each_entry(child, &bad_desc->tx_list, desc_node)
 413                 dwc_dump_lli(dwc, &child->lli);
 414
 415         spin_unlock_irqrestore(&dwc->lock, flags);
 416
 417         /* Pretend the descriptor completed successfully */
 418         dwc_descriptor_complete(dwc, bad_desc, true);
 419 }
 420
 421 /* --------------------- Cyclic DMA API extensions -------------------- */
 422
 423 inline dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan)
 424 {
 425         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 426         return channel_readl(dwc, SAR);
 427 }
 428 EXPORT_SYMBOL(dw_dma_get_src_addr);
 429
 430 inline dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan)
 431 {
 432         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 433         return channel_readl(dwc, DAR);
 434 }
 435 EXPORT_SYMBOL(dw_dma_get_dst_addr);
 436
 437 /* called with dwc->lock held and all DMAC interrupts disabled */
 438 static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
 439                 u32 status_block, u32 status_err, u32 status_xfer)
 440 {
 441         unsigned long flags;
 442
 443         if (status_block & dwc->mask) {
 444                 void (*callback)(void *param);
 445                 void *callback_param;
 446
 447                 dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp 0x%08x\n",
 448                                 channel_readl(dwc, LLP));
 449                 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
 450
 451                 callback = dwc->cdesc->period_callback;
 452                 callback_param = dwc->cdesc->period_callback_param;
 453
 454                 if (callback)
 455                         callback(callback_param);
 456         }
 457
 458         /*
 459          * Error and transfer complete are highly unlikely, and will most
 460          * likely be due to a configuration error by the user.
 461          */
 462         if (unlikely(status_err & dwc->mask) ||
 463                         unlikely(status_xfer & dwc->mask)) {
 464                 int i;
 465
 466                 dev_err(chan2dev(&dwc->chan), "cyclic DMA unexpected %s "
 467                                 "interrupt, stopping DMA transfer\n",
 468                                 status_xfer ? "xfer" : "error");
 469
 470                 spin_lock_irqsave(&dwc->lock, flags);
 471
 472                 dev_err(chan2dev(&dwc->chan),
 473                         "  SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
 474                         channel_readl(dwc, SAR),
 475                         channel_readl(dwc, DAR),
 476                         channel_readl(dwc, LLP),
 477                         channel_readl(dwc, CTL_HI),
 478                         channel_readl(dwc, CTL_LO));
 479
 480                 channel_clear_bit(dw, CH_EN, dwc->mask);
 481                 while (dma_readl(dw, CH_EN) & dwc->mask)
 482                         cpu_relax();
 483
 484                 /* make sure DMA does not restart by loading a new list */
 485                 channel_writel(dwc, LLP, 0);
 486                 channel_writel(dwc, CTL_LO, 0);
 487                 channel_writel(dwc, CTL_HI, 0);
 488
 489                 dma_writel(dw, CLEAR.BLOCK, dwc->mask);
 490                 dma_writel(dw, CLEAR.ERROR, dwc->mask);
 491                 dma_writel(dw, CLEAR.XFER, dwc->mask);
 492
 493                 for (i = 0; i < dwc->cdesc->periods; i++)
 494                         dwc_dump_lli(dwc, &dwc->cdesc->desc[i]->lli);
 495
 496                 spin_unlock_irqrestore(&dwc->lock, flags);
 497         }
 498 }
 499
 500 /* ------------------------------------------------------------------------- */
 501
 502 static void dw_dma_tasklet(unsigned long data)
 503 {
 504         struct dw_dma *dw = (struct dw_dma *)data;
 505         struct dw_dma_chan *dwc;
 506         u32 status_block;
 507         u32 status_xfer;
 508         u32 status_err;
 509         int i;
 510
 511         status_block = dma_readl(dw, RAW.BLOCK);
 512         status_xfer = dma_readl(dw, RAW.XFER);
 513         status_err = dma_readl(dw, RAW.ERROR);
 514
 515         dev_vdbg(dw->dma.dev, "tasklet: status_block=%x status_err=%x\n",
 516                         status_block, status_err);
 517
 518         for (i = 0; i < dw->dma.chancnt; i++) {
 519                 dwc = &dw->chan[i];
 520                 if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
 521                         dwc_handle_cyclic(dw, dwc, status_block, status_err,
 522                                         status_xfer);
 523                 else if (status_err & (1 << i))
 524                         dwc_handle_error(dw, dwc);
 525                 else if ((status_block | status_xfer) & (1 << i))
 526                         dwc_scan_descriptors(dw, dwc);
 527         }
 528
 529         /*
 530          * Re-enable interrupts. Block Complete interrupts are only
 531          * enabled if the INT_EN bit in the descriptor is set. This
 532          * will trigger a scan before the whole list is done.
 533          */
 534         channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
 535         channel_set_bit(dw, MASK.BLOCK, dw->all_chan_mask);
 536         channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask);
 537 }
 538
 539 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id)
 540 {
 541         struct dw_dma *dw = dev_id;
 542         u32 status;
 543
 544         dev_vdbg(dw->dma.dev, "interrupt: status=0x%x\n",
 545                         dma_readl(dw, STATUS_INT));
 546
 547         /*
 548          * Just disable the interrupts. We'll turn them back on in the
 549          * softirq handler.
 550          */
 551         channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
 552         channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
 553         channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
 554
 555         status = dma_readl(dw, STATUS_INT);
 556         if (status) {
 557                 dev_err(dw->dma.dev,
 558                         "BUG: Unexpected interrupts pending: 0x%x\n",
 559                         status);
 560
 561                 /* Try to recover */
 562                 channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1);
 563                 channel_clear_bit(dw, MASK.BLOCK, (1 << 8) - 1);
 564                 channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1);
 565                 channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1);
 566                 channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1);
 567         }
 568
 569         tasklet_schedule(&dw->tasklet);
 570
 571         return IRQ_HANDLED;
 572 }
 573
 574 /*----------------------------------------------------------------------*/
 575
 576 static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
 577 {
 578         struct dw_desc          *desc = txd_to_dw_desc(tx);
 579         struct dw_dma_chan      *dwc = to_dw_dma_chan(tx->chan);
 580         dma_cookie_t            cookie;
 581         unsigned long           flags;
 582
 583         spin_lock_irqsave(&dwc->lock, flags);
 584         cookie = dwc_assign_cookie(dwc, desc);
 585
 586         /*
 587          * REVISIT: We should attempt to chain as many descriptors as
 588          * possible, perhaps even appending to those already submitted
 589          * for DMA. But this is hard to do in a race-free manner.
 590          */
 591         if (list_empty(&dwc->active_list)) {
 592                 dev_vdbg(chan2dev(tx->chan), "tx_submit: started %u\n",
 593                                 desc->txd.cookie);
 594                 list_add_tail(&desc->desc_node, &dwc->active_list);
 595                 dwc_dostart(dwc, dwc_first_active(dwc));
 596         } else {
 597                 dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",
 598                                 desc->txd.cookie);
 599
 600                 list_add_tail(&desc->desc_node, &dwc->queue);
 601         }
 602
 603         spin_unlock_irqrestore(&dwc->lock, flags);
 604
 605         return cookie;
 606 }
 607
 608 static struct dma_async_tx_descriptor *
 609 dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 610                 size_t len, unsigned long flags)
 611 {
 612         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 613         struct dw_desc          *desc;
 614         struct dw_desc          *first;
 615         struct dw_desc          *prev;
 616         size_t                  xfer_count;
 617         size_t                  offset;
 618         unsigned int            src_width;
 619         unsigned int            dst_width;
 620         u32                     ctllo;
 621
 622         dev_vdbg(chan2dev(chan), "prep_dma_memcpy d0x%x s0x%x l0x%zx f0x%lx\n",
 623                         dest, src, len, flags);
 624
 625         if (unlikely(!len)) {
 626                 dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
 627                 return NULL;
 628         }
 629
 630         /*
 631          * We can be a lot more clever here, but this should take care
 632          * of the most common optimization.
 633          */
 634         if (!((src | dest  | len) & 7))
 635                 src_width = dst_width = 3;
 636         else if (!((src | dest  | len) & 3))
 637                 src_width = dst_width = 2;
 638         else if (!((src | dest | len) & 1))
 639                 src_width = dst_width = 1;
 640         else
 641                 src_width = dst_width = 0;
 642
 643         ctllo = DWC_DEFAULT_CTLLO(chan->private)
 644                         | DWC_CTLL_DST_WIDTH(dst_width)
 645                         | DWC_CTLL_SRC_WIDTH(src_width)
 646                         | DWC_CTLL_DST_INC
 647                         | DWC_CTLL_SRC_INC
 648                         | DWC_CTLL_FC_M2M;
 649         prev = first = NULL;
 650
 651         for (offset = 0; offset < len; offset += xfer_count << src_width) {
 652                 xfer_count = min_t(size_t, (len - offset) >> src_width,
 653                                 DWC_MAX_COUNT);
 654
 655                 desc = dwc_desc_get(dwc);
 656                 if (!desc)
 657                         goto err_desc_get;
 658
 659                 desc->lli.sar = src + offset;
 660                 desc->lli.dar = dest + offset;
 661                 desc->lli.ctllo = ctllo;
 662                 desc->lli.ctlhi = xfer_count;
 663
 664                 if (!first) {
 665                         first = desc;
 666                 } else {
 667                         prev->lli.llp = desc->txd.phys;
 668                         dma_sync_single_for_device(chan2parent(chan),
 669                                         prev->txd.phys, sizeof(prev->lli),
 670                                         DMA_TO_DEVICE);
 671                         list_add_tail(&desc->desc_node,
 672                                         &first->tx_list);
 673                 }
 674                 prev = desc;
 675         }
 676
 677
 678         if (flags & DMA_PREP_INTERRUPT)
 679                 /* Trigger interrupt after last block */
 680                 prev->lli.ctllo |= DWC_CTLL_INT_EN;
 681
 682         prev->lli.llp = 0;
 683         dma_sync_single_for_device(chan2parent(chan),
 684                         prev->txd.phys, sizeof(prev->lli),
 685                         DMA_TO_DEVICE);
 686
 687         first->txd.flags = flags;
 688         first->len = len;
 689
 690         return &first->txd;
 691
 692 err_desc_get:
 693         dwc_desc_put(dwc, first);
 694         return NULL;
 695 }
 696
 697 static struct dma_async_tx_descriptor *
 698 dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 699                 unsigned int sg_len, enum dma_data_direction direction,
 700                 unsigned long flags)
 701 {
 702         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 703         struct dw_dma_slave     *dws = chan->private;
 704         struct dw_desc          *prev;
 705         struct dw_desc          *first;
 706         u32                     ctllo;
 707         dma_addr_t              reg;
 708         unsigned int            reg_width;
 709         unsigned int            mem_width;
 710         unsigned int            i;
 711         struct scatterlist      *sg;
 712         size_t                  total_len = 0;
 713
 714         dev_vdbg(chan2dev(chan), "prep_dma_slave\n");
 715
 716         if (unlikely(!dws || !sg_len))
 717                 return NULL;
 718
 719         reg_width = dws->reg_width;
 720         prev = first = NULL;
 721
 722         switch (direction) {
 723         case DMA_TO_DEVICE:
 724                 ctllo = (DWC_DEFAULT_CTLLO(chan->private)
 725                                 | DWC_CTLL_DST_WIDTH(reg_width)
 726                                 | DWC_CTLL_DST_FIX
 727                                 | DWC_CTLL_SRC_INC
 728                                 | DWC_CTLL_FC(dws->fc));
 729                 reg = dws->tx_reg;
 730                 for_each_sg(sgl, sg, sg_len, i) {
 731                         struct dw_desc  *desc;
 732                         u32             len, dlen, mem;
 733
 734                         mem = sg_phys(sg);
 735                         len = sg_dma_len(sg);
 736                         mem_width = 2;
 737                         if (unlikely(mem & 3 || len & 3))
 738                                 mem_width = 0;
 739
 740 slave_sg_todev_fill_desc:
 741                         desc = dwc_desc_get(dwc);
 742                         if (!desc) {
 743                                 dev_err(chan2dev(chan),
 744                                         "not enough descriptors available\n");
 745                                 goto err_desc_get;
 746                         }
 747
 748                         desc->lli.sar = mem;
 749                         desc->lli.dar = reg;
 750                         desc->lli.ctllo = ctllo | DWC_CTLL_SRC_WIDTH(mem_width);
 751                         if ((len >> mem_width) > DWC_MAX_COUNT) {
 752                                 dlen = DWC_MAX_COUNT << mem_width;
 753                                 mem += dlen;
 754                                 len -= dlen;
 755                         } else {
 756                                 dlen = len;
 757                                 len = 0;
 758                         }
 759
 760                         desc->lli.ctlhi = dlen >> mem_width;
 761
 762                         if (!first) {
 763                                 first = desc;
 764                         } else {
 765                                 prev->lli.llp = desc->txd.phys;
 766                                 dma_sync_single_for_device(chan2parent(chan),
 767                                                 prev->txd.phys,
 768                                                 sizeof(prev->lli),
 769                                                 DMA_TO_DEVICE);
 770                                 list_add_tail(&desc->desc_node,
 771                                                 &first->tx_list);
 772                         }
 773                         prev = desc;
 774                         total_len += dlen;
 775
 776                         if (len)
 777                                 goto slave_sg_todev_fill_desc;
 778                 }
 779                 break;
 780         case DMA_FROM_DEVICE:
 781                 ctllo = (DWC_DEFAULT_CTLLO(chan->private)
 782                                 | DWC_CTLL_SRC_WIDTH(reg_width)
 783                                 | DWC_CTLL_DST_INC
 784                                 | DWC_CTLL_SRC_FIX
 785                                 | DWC_CTLL_FC(dws->fc));
 786
 787                 reg = dws->rx_reg;
 788                 for_each_sg(sgl, sg, sg_len, i) {
 789                         struct dw_desc  *desc;
 790                         u32             len, dlen, mem;
 791
 792                         mem = sg_phys(sg);
 793                         len = sg_dma_len(sg);
 794                         mem_width = 2;
 795                         if (unlikely(mem & 3 || len & 3))
 796                                 mem_width = 0;
 797
 798 slave_sg_fromdev_fill_desc:
 799                         desc = dwc_desc_get(dwc);
 800                         if (!desc) {
 801                                 dev_err(chan2dev(chan),
 802                                                 "not enough descriptors available\n");
 803                                 goto err_desc_get;
 804                         }
 805
 806                         desc->lli.sar = reg;
 807                         desc->lli.dar = mem;
 808                         desc->lli.ctllo = ctllo | DWC_CTLL_DST_WIDTH(mem_width);
 809                         if ((len >> reg_width) > DWC_MAX_COUNT) {
 810                                 dlen = DWC_MAX_COUNT << reg_width;
 811                                 mem += dlen;
 812                                 len -= dlen;
 813                         } else {
 814                                 dlen = len;
 815                                 len = 0;
 816                         }
 817                         desc->lli.ctlhi = dlen >> reg_width;
 818
 819                         if (!first) {
 820                                 first = desc;
 821                         } else {
 822                                 prev->lli.llp = desc->txd.phys;
 823                                 dma_sync_single_for_device(chan2parent(chan),
 824                                                 prev->txd.phys,
 825                                                 sizeof(prev->lli),
 826                                                 DMA_TO_DEVICE);
 827                                 list_add_tail(&desc->desc_node,
 828                                                 &first->tx_list);
 829                         }
 830                         prev = desc;
 831                         total_len += dlen;
 832
 833                         if (len)
 834                                 goto slave_sg_fromdev_fill_desc;
 835                 }
 836                 break;
 837         default:
 838                 return NULL;
 839         }
 840
 841         if (flags & DMA_PREP_INTERRUPT)
 842                 /* Trigger interrupt after last block */
 843                 prev->lli.ctllo |= DWC_CTLL_INT_EN;
 844
 845         prev->lli.llp = 0;
 846         dma_sync_single_for_device(chan2parent(chan),
 847                         prev->txd.phys, sizeof(prev->lli),
 848                         DMA_TO_DEVICE);
 849
 850         first->len = total_len;
 851
 852         return &first->txd;
 853
 854 err_desc_get:
 855         dwc_desc_put(dwc, first);
 856         return NULL;
 857 }
 858
 859 static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 860                        unsigned long arg)
 861 {
 862         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 863         struct dw_dma           *dw = to_dw_dma(chan->device);
 864         struct dw_desc          *desc, *_desc;
 865         unsigned long           flags;
 866         u32                     cfglo;
 867         LIST_HEAD(list);
 868
 869         if (cmd == DMA_PAUSE) {
 870                 spin_lock_irqsave(&dwc->lock, flags);
 871
 872                 cfglo = channel_readl(dwc, CFG_LO);
 873                 channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
 874                 while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY))
 875                         cpu_relax();
 876
 877                 dwc->paused = true;
 878                 spin_unlock_irqrestore(&dwc->lock, flags);
 879         } else if (cmd == DMA_RESUME) {
 880                 if (!dwc->paused)
 881                         return 0;
 882
 883                 spin_lock_irqsave(&dwc->lock, flags);
 884
 885                 cfglo = channel_readl(dwc, CFG_LO);
 886                 channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
 887                 dwc->paused = false;
 888
 889                 spin_unlock_irqrestore(&dwc->lock, flags);
 890         } else if (cmd == DMA_TERMINATE_ALL) {
 891                 spin_lock_irqsave(&dwc->lock, flags);
 892
 893                 channel_clear_bit(dw, CH_EN, dwc->mask);
 894                 while (dma_readl(dw, CH_EN) & dwc->mask)
 895                         cpu_relax();
 896
 897                 dwc->paused = false;
 898
 899                 /* active_list entries will end up before queued entries */
 900                 list_splice_init(&dwc->queue, &list);
 901                 list_splice_init(&dwc->active_list, &list);
 902
 903                 spin_unlock_irqrestore(&dwc->lock, flags);
 904
 905                 /* Flush all pending and queued descriptors */
 906                 list_for_each_entry_safe(desc, _desc, &list, desc_node)
 907                         dwc_descriptor_complete(dwc, desc, false);
 908         } else
 909                 return -ENXIO;
 910
 911         return 0;
 912 }
 913
 914 static enum dma_status
 915 dwc_tx_status(struct dma_chan *chan,
 916               dma_cookie_t cookie,
 917               struct dma_tx_state *txstate)
 918 {
 919         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 920         dma_cookie_t            last_used;
 921         dma_cookie_t            last_complete;
 922         int                     ret;
 923
 924         last_complete = dwc->completed;
 925         last_used = chan->cookie;
 926
 927         ret = dma_async_is_complete(cookie, last_complete, last_used);
 928         if (ret != DMA_SUCCESS) {
 929                 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
 930
 931                 last_complete = dwc->completed;
 932                 last_used = chan->cookie;
 933
 934                 ret = dma_async_is_complete(cookie, last_complete, last_used);
 935         }
 936
 937         if (ret != DMA_SUCCESS)
 938                 dma_set_tx_state(txstate, last_complete, last_used,
 939                                 dwc_first_active(dwc)->len);
 940         else
 941                 dma_set_tx_state(txstate, last_complete, last_used, 0);
 942
 943         if (dwc->paused)
 944                 return DMA_PAUSED;
 945
 946         return ret;
 947 }
 948
 949 static void dwc_issue_pending(struct dma_chan *chan)
 950 {
 951         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 952
 953         if (!list_empty(&dwc->queue))
 954                 dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
 955 }
 956
 957 static int dwc_alloc_chan_resources(struct dma_chan *chan)
 958 {
 959         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
 960         struct dw_dma           *dw = to_dw_dma(chan->device);
 961         struct dw_desc          *desc;
 962         struct dw_dma_slave     *dws;
 963         int                     i;
 964         u32                     cfghi;
 965         u32                     cfglo;
 966         unsigned long           flags;
 967
 968         dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
 969
 970         /* ASSERT:  channel is idle */
 971         if (dma_readl(dw, CH_EN) & dwc->mask) {
 972                 dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
 973                 return -EIO;
 974         }
 975
 976         dwc->completed = chan->cookie = 1;
 977
 978         cfghi = DWC_CFGH_FIFO_MODE;
 979         cfglo = 0;
 980
 981         dws = chan->private;
 982         if (dws) {
 983                 /*
 984                  * We need controller-specific data to set up slave
 985                  * transfers.
 986                  */
 987                 BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev);
 988
 989                 cfghi = dws->cfg_hi;
 990                 cfglo = dws->cfg_lo & ~DWC_CFGL_CH_PRIOR_MASK;
 991         }
 992
 993         cfglo |= DWC_CFGL_CH_PRIOR(dwc->priority);
 994
 995         channel_writel(dwc, CFG_LO, cfglo);
 996         channel_writel(dwc, CFG_HI, cfghi);
 997
 998         /*
 999          * NOTE: some controllers may have additional features that we
1000          * need to initialize here, like "scatter-gather" (which
1001          * doesn't mean what you think it means), and status writeback.
1002          */
1003
1004         spin_lock_irqsave(&dwc->lock, flags);
1005         i = dwc->descs_allocated;
1006         while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) {
1007                 spin_unlock_irqrestore(&dwc->lock, flags);
1008
1009                 desc = kzalloc(sizeof(struct dw_desc), GFP_KERNEL);
1010                 if (!desc) {
1011                         dev_info(chan2dev(chan),
1012                                 "only allocated %d descriptors\n", i);
1013                         spin_lock_irqsave(&dwc->lock, flags);
1014                         break;
1015                 }
1016
1017                 INIT_LIST_HEAD(&desc->tx_list);
1018                 dma_async_tx_descriptor_init(&desc->txd, chan);
1019                 desc->txd.tx_submit = dwc_tx_submit;
1020                 desc->txd.flags = DMA_CTRL_ACK;
1021                 desc->txd.phys = dma_map_single(chan2parent(chan), &desc->lli,
1022                                 sizeof(desc->lli), DMA_TO_DEVICE);
1023                 dwc_desc_put(dwc, desc);
1024
1025                 spin_lock_irqsave(&dwc->lock, flags);
1026                 i = ++dwc->descs_allocated;
1027         }
1028
1029         /* Enable interrupts */
1030         channel_set_bit(dw, MASK.XFER, dwc->mask);
1031         channel_set_bit(dw, MASK.BLOCK, dwc->mask);
1032         channel_set_bit(dw, MASK.ERROR, dwc->mask);
1033
1034         spin_unlock_irqrestore(&dwc->lock, flags);
1035
1036         dev_dbg(chan2dev(chan),
1037                 "alloc_chan_resources allocated %d descriptors\n", i);
1038
1039         return i;
1040 }
1041
1042 static void dwc_free_chan_resources(struct dma_chan *chan)
1043 {
1044         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1045         struct dw_dma           *dw = to_dw_dma(chan->device);
1046         struct dw_desc          *desc, *_desc;
1047         unsigned long           flags;
1048         LIST_HEAD(list);
1049
1050         dev_dbg(chan2dev(chan), "free_chan_resources (descs allocated=%u)\n",
1051                         dwc->descs_allocated);
1052
1053         /* ASSERT:  channel is idle */
1054         BUG_ON(!list_empty(&dwc->active_list));
1055         BUG_ON(!list_empty(&dwc->queue));
1056         BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
1057
1058         spin_lock_irqsave(&dwc->lock, flags);
1059         list_splice_init(&dwc->free_list, &list);
1060         dwc->descs_allocated = 0;
1061
1062         /* Disable interrupts */
1063         channel_clear_bit(dw, MASK.XFER, dwc->mask);
1064         channel_clear_bit(dw, MASK.BLOCK, dwc->mask);
1065         channel_clear_bit(dw, MASK.ERROR, dwc->mask);
1066
1067         spin_unlock_irqrestore(&dwc->lock, flags);
1068
1069         list_for_each_entry_safe(desc, _desc, &list, desc_node) {
1070                 dev_vdbg(chan2dev(chan), "  freeing descriptor %p\n", desc);
1071                 dma_unmap_single(chan2parent(chan), desc->txd.phys,
1072                                 sizeof(desc->lli), DMA_TO_DEVICE);
1073                 kfree(desc);
1074         }
1075
1076         dev_vdbg(chan2dev(chan), "free_chan_resources done\n");
1077 }
1078
1079 /* --------------------- Cyclic DMA API extensions -------------------- */
1080
1081 /**
1082  * dw_dma_cyclic_start - start the cyclic DMA transfer
1083  * @chan: the DMA channel to start
1084  *
1085  * Must be called with soft interrupts disabled. Returns zero on success or
1086  * -errno on failure.
1087  */
1088 int dw_dma_cyclic_start(struct dma_chan *chan)
1089 {
1090         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1091         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
1092         unsigned long           flags;
1093
1094         if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
1095                 dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n");
1096                 return -ENODEV;
1097         }
1098
1099         spin_lock_irqsave(&dwc->lock, flags);
1100
1101         /* assert channel is idle */
1102         if (dma_readl(dw, CH_EN) & dwc->mask) {
1103                 dev_err(chan2dev(&dwc->chan),
1104                         "BUG: Attempted to start non-idle channel\n");
1105                 dev_err(chan2dev(&dwc->chan),
1106                         "  SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
1107                         channel_readl(dwc, SAR),
1108                         channel_readl(dwc, DAR),
1109                         channel_readl(dwc, LLP),
1110                         channel_readl(dwc, CTL_HI),
1111                         channel_readl(dwc, CTL_LO));
1112                 spin_unlock_irqrestore(&dwc->lock, flags);
1113                 return -EBUSY;
1114         }
1115
1116         dma_writel(dw, CLEAR.BLOCK, dwc->mask);
1117         dma_writel(dw, CLEAR.ERROR, dwc->mask);
1118         dma_writel(dw, CLEAR.XFER, dwc->mask);
1119
1120         /* setup DMAC channel registers */
1121         channel_writel(dwc, LLP, dwc->cdesc->desc[0]->txd.phys);
1122         channel_writel(dwc, CTL_LO, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
1123         channel_writel(dwc, CTL_HI, 0);
1124
1125         channel_set_bit(dw, CH_EN, dwc->mask);
1126
1127         spin_unlock_irqrestore(&dwc->lock, flags);
1128
1129         return 0;
1130 }
1131 EXPORT_SYMBOL(dw_dma_cyclic_start);
1132
1133 /**
1134  * dw_dma_cyclic_stop - stop the cyclic DMA transfer
1135  * @chan: the DMA channel to stop
1136  *
1137  * Must be called with soft interrupts disabled.
1138  */
1139 void dw_dma_cyclic_stop(struct dma_chan *chan)
1140 {
1141         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1142         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
1143         unsigned long           flags;
1144
1145         spin_lock_irqsave(&dwc->lock, flags);
1146
1147         channel_clear_bit(dw, CH_EN, dwc->mask);
1148         while (dma_readl(dw, CH_EN) & dwc->mask)
1149                 cpu_relax();
1150
1151         spin_unlock_irqrestore(&dwc->lock, flags);
1152 }
1153 EXPORT_SYMBOL(dw_dma_cyclic_stop);
1154
1155 /**
1156  * dw_dma_cyclic_prep - prepare the cyclic DMA transfer
1157  * @chan: the DMA channel to prepare
1158  * @buf_addr: physical DMA address where the buffer starts
1159  * @buf_len: total number of bytes for the entire buffer
1160  * @period_len: number of bytes for each period
1161  * @direction: transfer direction, to or from device
1162  *
1163  * Must be called before trying to start the transfer. Returns a valid struct
1164  * dw_cyclic_desc if successful or an ERR_PTR(-errno) if not successful.
1165  */
1166 struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
1167                 dma_addr_t buf_addr, size_t buf_len, size_t period_len,
1168                 enum dma_data_direction direction)
1169 {
1170         struct dw_dma_chan              *dwc = to_dw_dma_chan(chan);
1171         struct dw_cyclic_desc           *cdesc;
1172         struct dw_cyclic_desc           *retval = NULL;
1173         struct dw_desc                  *desc;
1174         struct dw_desc                  *last = NULL;
1175         struct dw_dma_slave             *dws = chan->private;
1176         unsigned long                   was_cyclic;
1177         unsigned int                    reg_width;
1178         unsigned int                    periods;
1179         unsigned int                    i;
1180         unsigned long                   flags;
1181
1182         spin_lock_irqsave(&dwc->lock, flags);
1183         if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) {
1184                 spin_unlock_irqrestore(&dwc->lock, flags);
1185                 dev_dbg(chan2dev(&dwc->chan),
1186                                 "queue and/or active list are not empty\n");
1187                 return ERR_PTR(-EBUSY);
1188         }
1189
1190         was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1191         spin_unlock_irqrestore(&dwc->lock, flags);
1192         if (was_cyclic) {
1193                 dev_dbg(chan2dev(&dwc->chan),
1194                                 "channel already prepared for cyclic DMA\n");
1195                 return ERR_PTR(-EBUSY);
1196         }
1197
1198         retval = ERR_PTR(-EINVAL);
1199         reg_width = dws->reg_width;
1200         periods = buf_len / period_len;
1201
1202         /* Check for too big/unaligned periods and unaligned DMA buffer. */
1203         if (period_len > (DWC_MAX_COUNT << reg_width))
1204                 goto out_err;
1205         if (unlikely(period_len & ((1 << reg_width) - 1)))
1206                 goto out_err;
1207         if (unlikely(buf_addr & ((1 << reg_width) - 1)))
1208                 goto out_err;
1209         if (unlikely(!(direction & (DMA_TO_DEVICE | DMA_FROM_DEVICE))))
1210                 goto out_err;
1211
1212         retval = ERR_PTR(-ENOMEM);
1213
1214         if (periods > NR_DESCS_PER_CHANNEL)
1215                 goto out_err;
1216
1217         cdesc = kzalloc(sizeof(struct dw_cyclic_desc), GFP_KERNEL);
1218         if (!cdesc)
1219                 goto out_err;
1220
1221         cdesc->desc = kzalloc(sizeof(struct dw_desc *) * periods, GFP_KERNEL);
1222         if (!cdesc->desc)
1223                 goto out_err_alloc;
1224
1225         for (i = 0; i < periods; i++) {
1226                 desc = dwc_desc_get(dwc);
1227                 if (!desc)
1228                         goto out_err_desc_get;
1229
1230                 switch (direction) {
1231                 case DMA_TO_DEVICE:
1232                         desc->lli.dar = dws->tx_reg;
1233                         desc->lli.sar = buf_addr + (period_len * i);
1234                         desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan->private)
1235                                         | DWC_CTLL_DST_WIDTH(reg_width)
1236                                         | DWC_CTLL_SRC_WIDTH(reg_width)
1237                                         | DWC_CTLL_DST_FIX
1238                                         | DWC_CTLL_SRC_INC
1239                                         | DWC_CTLL_FC(dws->fc)
1240                                         | DWC_CTLL_INT_EN);
1241                         break;
1242                 case DMA_FROM_DEVICE:
1243                         desc->lli.dar = buf_addr + (period_len * i);
1244                         desc->lli.sar = dws->rx_reg;
1245                         desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan->private)
1246                                         | DWC_CTLL_SRC_WIDTH(reg_width)
1247                                         | DWC_CTLL_DST_WIDTH(reg_width)
1248                                         | DWC_CTLL_DST_INC
1249                                         | DWC_CTLL_SRC_FIX
1250                                         | DWC_CTLL_FC(dws->fc)
1251                                         | DWC_CTLL_INT_EN);
1252                         break;
1253                 default:
1254                         break;
1255                 }
1256
1257                 desc->lli.ctlhi = (period_len >> reg_width);
1258                 cdesc->desc[i] = desc;
1259
1260                 if (last) {
1261                         last->lli.llp = desc->txd.phys;
1262                         dma_sync_single_for_device(chan2parent(chan),
1263                                         last->txd.phys, sizeof(last->lli),
1264                                         DMA_TO_DEVICE);
1265                 }
1266
1267                 last = desc;
1268         }
1269
1270         /* lets make a cyclic list */
1271         last->lli.llp = cdesc->desc[0]->txd.phys;
1272         dma_sync_single_for_device(chan2parent(chan), last->txd.phys,
1273                         sizeof(last->lli), DMA_TO_DEVICE);
1274
1275         dev_dbg(chan2dev(&dwc->chan), "cyclic prepared buf 0x%08x len %zu "
1276                         "period %zu periods %d\n", buf_addr, buf_len,
1277                         period_len, periods);
1278
1279         cdesc->periods = periods;
1280         dwc->cdesc = cdesc;
1281
1282         return cdesc;
1283
1284 out_err_desc_get:
1285         while (i--)
1286                 dwc_desc_put(dwc, cdesc->desc[i]);
1287 out_err_alloc:
1288         kfree(cdesc);
1289 out_err:
1290         clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1291         return (struct dw_cyclic_desc *)retval;
1292 }
1293 EXPORT_SYMBOL(dw_dma_cyclic_prep);
1294
1295 /**
1296  * dw_dma_cyclic_free - free a prepared cyclic DMA transfer
1297  * @chan: the DMA channel to free
1298  */
1299 void dw_dma_cyclic_free(struct dma_chan *chan)
1300 {
1301         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
1302         struct dw_dma           *dw = to_dw_dma(dwc->chan.device);
1303         struct dw_cyclic_desc   *cdesc = dwc->cdesc;
1304         int                     i;
1305         unsigned long           flags;
1306
1307         dev_dbg(chan2dev(&dwc->chan), "cyclic free\n");
1308
1309         if (!cdesc)
1310                 return;
1311
1312         spin_lock_irqsave(&dwc->lock, flags);
1313
1314         channel_clear_bit(dw, CH_EN, dwc->mask);
1315         while (dma_readl(dw, CH_EN) & dwc->mask)
1316                 cpu_relax();
1317
1318         dma_writel(dw, CLEAR.BLOCK, dwc->mask);
1319         dma_writel(dw, CLEAR.ERROR, dwc->mask);
1320         dma_writel(dw, CLEAR.XFER, dwc->mask);
1321
1322         spin_unlock_irqrestore(&dwc->lock, flags);
1323
1324         for (i = 0; i < cdesc->periods; i++)
1325                 dwc_desc_put(dwc, cdesc->desc[i]);
1326
1327         kfree(cdesc->desc);
1328         kfree(cdesc);
1329
1330         clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
1331 }
1332 EXPORT_SYMBOL(dw_dma_cyclic_free);
1333
1334 /*----------------------------------------------------------------------*/
1335
1336 static void dw_dma_off(struct dw_dma *dw)
1337 {
1338         dma_writel(dw, CFG, 0);
1339
1340         channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1341         channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1342         channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1343         channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1344         channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1345
1346         while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
1347                 cpu_relax();
1348 }
1349
1350 static int __init dw_probe(struct platform_device *pdev)
1351 {
1352         struct dw_dma_platform_data *pdata;
1353         struct resource         *io;
1354         struct dw_dma           *dw;
1355         size_t                  size;
1356         int                     irq;
1357         int                     err;
1358         int                     i;
1359
1360         pdata = pdev->dev.platform_data;
1361         if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS)
1362                 return -EINVAL;
1363
1364         io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1365         if (!io)
1366                 return -EINVAL;
1367
1368         irq = platform_get_irq(pdev, 0);
1369         if (irq < 0)
1370                 return irq;
1371
1372         size = sizeof(struct dw_dma);
1373         size += pdata->nr_channels * sizeof(struct dw_dma_chan);
1374         dw = kzalloc(size, GFP_KERNEL);
1375         if (!dw)
1376                 return -ENOMEM;
1377
1378         if (!request_mem_region(io->start, DW_REGLEN, pdev->dev.driver->name)) {
1379                 err = -EBUSY;
1380                 goto err_kfree;
1381         }
1382
1383         dw->regs = ioremap(io->start, DW_REGLEN);
1384         if (!dw->regs) {
1385                 err = -ENOMEM;
1386                 goto err_release_r;
1387         }
1388
1389         dw->clk = clk_get(&pdev->dev, "hclk");
1390         if (IS_ERR(dw->clk)) {
1391                 err = PTR_ERR(dw->clk);
1392                 goto err_clk;
1393         }
1394         clk_enable(dw->clk);
1395
1396         /* force dma off, just in case */
1397         dw_dma_off(dw);
1398
1399         err = request_irq(irq, dw_dma_interrupt, 0, "dw_dmac", dw);
1400         if (err)
1401                 goto err_irq;
1402
1403         platform_set_drvdata(pdev, dw);
1404
1405         tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
1406
1407         dw->all_chan_mask = (1 << pdata->nr_channels) - 1;
1408
1409         INIT_LIST_HEAD(&dw->dma.channels);
1410         for (i = 0; i < pdata->nr_channels; i++) {
1411                 struct dw_dma_chan      *dwc = &dw->chan[i];
1412
1413                 dwc->chan.device = &dw->dma;
1414                 dwc->chan.cookie = dwc->completed = 1;
1415                 if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING)
1416                         list_add_tail(&dwc->chan.device_node,
1417                                         &dw->dma.channels);
1418                 else
1419                         list_add(&dwc->chan.device_node, &dw->dma.channels);
1420
1421                 /* 7 is highest priority & 0 is lowest. */
1422                 if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING)
1423                         dwc->priority = 7 - i;
1424                 else
1425                         dwc->priority = i;
1426
1427                 dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
1428                 spin_lock_init(&dwc->lock);
1429                 dwc->mask = 1 << i;
1430
1431                 INIT_LIST_HEAD(&dwc->active_list);
1432                 INIT_LIST_HEAD(&dwc->queue);
1433                 INIT_LIST_HEAD(&dwc->free_list);
1434
1435                 channel_clear_bit(dw, CH_EN, dwc->mask);
1436         }
1437
1438         /* Clear/disable all interrupts on all channels. */
1439         dma_writel(dw, CLEAR.XFER, dw->all_chan_mask);
1440         dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask);
1441         dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask);
1442         dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask);
1443         dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask);
1444
1445         channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
1446         channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
1447         channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask);
1448         channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask);
1449         channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask);
1450
1451         dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
1452         dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
1453         if (pdata->is_private)
1454                 dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask);
1455         dw->dma.dev = &pdev->dev;
1456         dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
1457         dw->dma.device_free_chan_resources = dwc_free_chan_resources;
1458
1459         dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
1460
1461         dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
1462         dw->dma.device_control = dwc_control;
1463
1464         dw->dma.device_tx_status = dwc_tx_status;
1465         dw->dma.device_issue_pending = dwc_issue_pending;
1466
1467         dma_writel(dw, CFG, DW_CFG_DMA_EN);
1468
1469         printk(KERN_INFO "%s: DesignWare DMA Controller, %d channels\n",
1470                         dev_name(&pdev->dev), pdata->nr_channels);
1471
1472         dma_async_device_register(&dw->dma);
1473
1474         return 0;
1475
1476 err_irq:
1477         clk_disable(dw->clk);
1478         clk_put(dw->clk);
1479 err_clk:
1480         iounmap(dw->regs);
1481         dw->regs = NULL;
1482 err_release_r:
1483         release_resource(io);
1484 err_kfree:
1485         kfree(dw);
1486         return err;
1487 }
1488
1489 static int __exit dw_remove(struct platform_device *pdev)
1490 {
1491         struct dw_dma           *dw = platform_get_drvdata(pdev);
1492         struct dw_dma_chan      *dwc, *_dwc;
1493         struct resource         *io;
1494
1495         dw_dma_off(dw);
1496         dma_async_device_unregister(&dw->dma);
1497
1498         free_irq(platform_get_irq(pdev, 0), dw);
1499         tasklet_kill(&dw->tasklet);
1500
1501         list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,
1502                         chan.device_node) {
1503                 list_del(&dwc->chan.device_node);
1504                 channel_clear_bit(dw, CH_EN, dwc->mask);
1505         }
1506
1507         clk_disable(dw->clk);
1508         clk_put(dw->clk);
1509
1510         iounmap(dw->regs);
1511         dw->regs = NULL;
1512
1513         io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1514         release_mem_region(io->start, DW_REGLEN);
1515
1516         kfree(dw);
1517
1518         return 0;
1519 }
1520
1521 static void dw_shutdown(struct platform_device *pdev)
1522 {
1523         struct dw_dma   *dw = platform_get_drvdata(pdev);
1524
1525         dw_dma_off(platform_get_drvdata(pdev));
1526         clk_disable(dw->clk);
1527 }
1528
1529 static int dw_suspend_noirq(struct device *dev)
1530 {
1531         struct platform_device *pdev = to_platform_device(dev);
1532         struct dw_dma   *dw = platform_get_drvdata(pdev);
1533
1534         dw_dma_off(platform_get_drvdata(pdev));
1535         clk_disable(dw->clk);
1536         return 0;
1537 }
1538
1539 static int dw_resume_noirq(struct device *dev)
1540 {
1541         struct platform_device *pdev = to_platform_device(dev);
1542         struct dw_dma   *dw = platform_get_drvdata(pdev);
1543
1544         clk_enable(dw->clk);
1545         dma_writel(dw, CFG, DW_CFG_DMA_EN);
1546         return 0;
1547 }
1548
1549 static const struct dev_pm_ops dw_dev_pm_ops = {
1550         .suspend_noirq = dw_suspend_noirq,
1551         .resume_noirq = dw_resume_noirq,
1552 };
1553
1554 static struct platform_driver dw_driver = {
1555         .remove         = __exit_p(dw_remove),
1556         .shutdown       = dw_shutdown,
1557         .driver = {
1558                 .name   = "dw_dmac",
1559                 .pm     = &dw_dev_pm_ops,
1560         },
1561 };
1562
1563 static int __init dw_init(void)
1564 {
1565         return platform_driver_probe(&dw_driver, dw_probe);
1566 }
1567 subsys_initcall(dw_init);
1568
1569 static void __exit dw_exit(void)
1570 {
1571         platform_driver_unregister(&dw_driver);
1572 }
1573 module_exit(dw_exit);
1574
1575 MODULE_LICENSE("GPL v2");
1576 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller driver");
1577 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
1578 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@st.com>");