drivers/dma/sirf-dma.c

   1 /*
   2  * DMA controller driver for CSR SiRFprimaII
   3  *
   4  * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
   5  *
   6  * Licensed under GPLv2 or later.
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/dmaengine.h>
  11 #include <linux/dma-mapping.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/io.h>
  14 #include <linux/slab.h>
  15 #include <linux/of_irq.h>
  16 #include <linux/of_address.h>
  17 #include <linux/of_device.h>
  18 #include <linux/of_platform.h>
  19 #include <linux/sirfsoc_dma.h>
  20
  21 #include "dmaengine.h"
  22
  23 #define SIRFSOC_DMA_DESCRIPTORS                 16
  24 #define SIRFSOC_DMA_CHANNELS                    16
  25
  26 #define SIRFSOC_DMA_CH_ADDR                     0x00
  27 #define SIRFSOC_DMA_CH_XLEN                     0x04
  28 #define SIRFSOC_DMA_CH_YLEN                     0x08
  29 #define SIRFSOC_DMA_CH_CTRL                     0x0C
  30
  31 #define SIRFSOC_DMA_WIDTH_0                     0x100
  32 #define SIRFSOC_DMA_CH_VALID                    0x140
  33 #define SIRFSOC_DMA_CH_INT                      0x144
  34 #define SIRFSOC_DMA_INT_EN                      0x148
  35 #define SIRFSOC_DMA_CH_LOOP_CTRL                0x150
  36
  37 #define SIRFSOC_DMA_MODE_CTRL_BIT               4
  38 #define SIRFSOC_DMA_DIR_CTRL_BIT                5
  39
  40 /* xlen and dma_width register is in 4 bytes boundary */
  41 #define SIRFSOC_DMA_WORD_LEN                    4
  42
  43 struct sirfsoc_dma_desc {
  44         struct dma_async_tx_descriptor  desc;
  45         struct list_head                node;
  46
  47         /* SiRFprimaII 2D-DMA parameters */
  48
  49         int             xlen;           /* DMA xlen */
  50         int             ylen;           /* DMA ylen */
  51         int             width;          /* DMA width */
  52         int             dir;
  53         bool            cyclic;         /* is loop DMA? */
  54         u32             addr;           /* DMA buffer address */
  55 };
  56
  57 struct sirfsoc_dma_chan {
  58         struct dma_chan                 chan;
  59         struct list_head                free;
  60         struct list_head                prepared;
  61         struct list_head                queued;
  62         struct list_head                active;
  63         struct list_head                completed;
  64         unsigned long                   happened_cyclic;
  65         unsigned long                   completed_cyclic;
  66
  67         /* Lock for this structure */
  68         spinlock_t                      lock;
  69
  70         int                             mode;
  71 };
  72
  73 struct sirfsoc_dma {
  74         struct dma_device               dma;
  75         struct tasklet_struct           tasklet;
  76         struct sirfsoc_dma_chan         channels[SIRFSOC_DMA_CHANNELS];
  77         void __iomem                    *base;
  78         int                             irq;
  79 };
  80
  81 #define DRV_NAME        "sirfsoc_dma"
  82
  83 /* Convert struct dma_chan to struct sirfsoc_dma_chan */
  84 static inline
  85 struct sirfsoc_dma_chan *dma_chan_to_sirfsoc_dma_chan(struct dma_chan *c)
  86 {
  87         return container_of(c, struct sirfsoc_dma_chan, chan);
  88 }
  89
  90 /* Convert struct dma_chan to struct sirfsoc_dma */
  91 static inline struct sirfsoc_dma *dma_chan_to_sirfsoc_dma(struct dma_chan *c)
  92 {
  93         struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(c);
  94         return container_of(schan, struct sirfsoc_dma, channels[c->chan_id]);
  95 }
  96
  97 /* Execute all queued DMA descriptors */
  98 static void sirfsoc_dma_execute(struct sirfsoc_dma_chan *schan)
  99 {
 100         struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(&schan->chan);
 101         int cid = schan->chan.chan_id;
 102         struct sirfsoc_dma_desc *sdesc = NULL;
 103
 104         /*
 105          * lock has been held by functions calling this, so we don't hold
 106          * lock again
 107          */
 108
 109         sdesc = list_first_entry(&schan->queued, struct sirfsoc_dma_desc,
 110                 node);
 111         /* Move the first queued descriptor to active list */
 112         list_move_tail(&sdesc->node, &schan->active);
 113
 114         /* Start the DMA transfer */
 115         writel_relaxed(sdesc->width, sdma->base + SIRFSOC_DMA_WIDTH_0 +
 116                 cid * 4);
 117         writel_relaxed(cid | (schan->mode << SIRFSOC_DMA_MODE_CTRL_BIT) |
 118                 (sdesc->dir << SIRFSOC_DMA_DIR_CTRL_BIT),
 119                 sdma->base + cid * 0x10 + SIRFSOC_DMA_CH_CTRL);
 120         writel_relaxed(sdesc->xlen, sdma->base + cid * 0x10 +
 121                 SIRFSOC_DMA_CH_XLEN);
 122         writel_relaxed(sdesc->ylen, sdma->base + cid * 0x10 +
 123                 SIRFSOC_DMA_CH_YLEN);
 124         writel_relaxed(readl_relaxed(sdma->base + SIRFSOC_DMA_INT_EN) |
 125                 (1 << cid), sdma->base + SIRFSOC_DMA_INT_EN);
 126
 127         /*
 128          * writel has an implict memory write barrier to make sure data is
 129          * flushed into memory before starting DMA
 130          */
 131         writel(sdesc->addr >> 2, sdma->base + cid * 0x10 + SIRFSOC_DMA_CH_ADDR);
 132
 133         if (sdesc->cyclic) {
 134                 writel((1 << cid) | 1 << (cid + 16) |
 135                         readl_relaxed(sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL),
 136                         sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL);
 137                 schan->happened_cyclic = schan->completed_cyclic = 0;
 138         }
 139 }
 140
 141 /* Interrupt handler */
 142 static irqreturn_t sirfsoc_dma_irq(int irq, void *data)
 143 {
 144         struct sirfsoc_dma *sdma = data;
 145         struct sirfsoc_dma_chan *schan;
 146         struct sirfsoc_dma_desc *sdesc = NULL;
 147         u32 is;
 148         int ch;
 149
 150         is = readl(sdma->base + SIRFSOC_DMA_CH_INT);
 151         while ((ch = fls(is) - 1) >= 0) {
 152                 is &= ~(1 << ch);
 153                 writel_relaxed(1 << ch, sdma->base + SIRFSOC_DMA_CH_INT);
 154                 schan = &sdma->channels[ch];
 155
 156                 spin_lock(&schan->lock);
 157
 158                 sdesc = list_first_entry(&schan->active, struct sirfsoc_dma_desc,
 159                         node);
 160                 if (!sdesc->cyclic) {
 161                         /* Execute queued descriptors */
 162                         list_splice_tail_init(&schan->active, &schan->completed);
 163                         if (!list_empty(&schan->queued))
 164                                 sirfsoc_dma_execute(schan);
 165                 } else
 166                         schan->happened_cyclic++;
 167
 168                 spin_unlock(&schan->lock);
 169         }
 170
 171         /* Schedule tasklet */
 172         tasklet_schedule(&sdma->tasklet);
 173
 174         return IRQ_HANDLED;
 175 }
 176
 177 /* process completed descriptors */
 178 static void sirfsoc_dma_process_completed(struct sirfsoc_dma *sdma)
 179 {
 180         dma_cookie_t last_cookie = 0;
 181         struct sirfsoc_dma_chan *schan;
 182         struct sirfsoc_dma_desc *sdesc;
 183         struct dma_async_tx_descriptor *desc;
 184         unsigned long flags;
 185         unsigned long happened_cyclic;
 186         LIST_HEAD(list);
 187         int i;
 188
 189         for (i = 0; i < sdma->dma.chancnt; i++) {
 190                 schan = &sdma->channels[i];
 191
 192                 /* Get all completed descriptors */
 193                 spin_lock_irqsave(&schan->lock, flags);
 194                 if (!list_empty(&schan->completed)) {
 195                         list_splice_tail_init(&schan->completed, &list);
 196                         spin_unlock_irqrestore(&schan->lock, flags);
 197
 198                         /* Execute callbacks and run dependencies */
 199                         list_for_each_entry(sdesc, &list, node) {
 200                                 desc = &sdesc->desc;
 201
 202                                 if (desc->callback)
 203                                         desc->callback(desc->callback_param);
 204
 205                                 last_cookie = desc->cookie;
 206                                 dma_run_dependencies(desc);
 207                         }
 208
 209                         /* Free descriptors */
 210                         spin_lock_irqsave(&schan->lock, flags);
 211                         list_splice_tail_init(&list, &schan->free);
 212                         schan->chan.completed_cookie = last_cookie;
 213                         spin_unlock_irqrestore(&schan->lock, flags);
 214                 } else {
 215                         /* for cyclic channel, desc is always in active list */
 216                         sdesc = list_first_entry(&schan->active, struct sirfsoc_dma_desc,
 217                                 node);
 218
 219                         if (!sdesc || (sdesc && !sdesc->cyclic)) {
 220                                 /* without active cyclic DMA */
 221                                 spin_unlock_irqrestore(&schan->lock, flags);
 222                                 continue;
 223                         }
 224
 225                         /* cyclic DMA */
 226                         happened_cyclic = schan->happened_cyclic;
 227                         spin_unlock_irqrestore(&schan->lock, flags);
 228
 229                         desc = &sdesc->desc;
 230                         while (happened_cyclic != schan->completed_cyclic) {
 231                                 if (desc->callback)
 232                                         desc->callback(desc->callback_param);
 233                                 schan->completed_cyclic++;
 234                         }
 235                 }
 236         }
 237 }
 238
 239 /* DMA Tasklet */
 240 static void sirfsoc_dma_tasklet(unsigned long data)
 241 {
 242         struct sirfsoc_dma *sdma = (void *)data;
 243
 244         sirfsoc_dma_process_completed(sdma);
 245 }
 246
 247 /* Submit descriptor to hardware */
 248 static dma_cookie_t sirfsoc_dma_tx_submit(struct dma_async_tx_descriptor *txd)
 249 {
 250         struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(txd->chan);
 251         struct sirfsoc_dma_desc *sdesc;
 252         unsigned long flags;
 253         dma_cookie_t cookie;
 254
 255         sdesc = container_of(txd, struct sirfsoc_dma_desc, desc);
 256
 257         spin_lock_irqsave(&schan->lock, flags);
 258
 259         /* Move descriptor to queue */
 260         list_move_tail(&sdesc->node, &schan->queued);
 261
 262         cookie = dma_cookie_assign(txd);
 263
 264         spin_unlock_irqrestore(&schan->lock, flags);
 265
 266         return cookie;
 267 }
 268
 269 static int sirfsoc_dma_slave_config(struct sirfsoc_dma_chan *schan,
 270         struct dma_slave_config *config)
 271 {
 272         unsigned long flags;
 273
 274         if ((config->src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) ||
 275                 (config->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES))
 276                 return -EINVAL;
 277
 278         spin_lock_irqsave(&schan->lock, flags);
 279         schan->mode = (config->src_maxburst == 4 ? 1 : 0);
 280         spin_unlock_irqrestore(&schan->lock, flags);
 281
 282         return 0;
 283 }
 284
 285 static int sirfsoc_dma_terminate_all(struct sirfsoc_dma_chan *schan)
 286 {
 287         struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(&schan->chan);
 288         int cid = schan->chan.chan_id;
 289         unsigned long flags;
 290
 291         writel_relaxed(readl_relaxed(sdma->base + SIRFSOC_DMA_INT_EN) &
 292                 ~(1 << cid), sdma->base + SIRFSOC_DMA_INT_EN);
 293         writel_relaxed(1 << cid, sdma->base + SIRFSOC_DMA_CH_VALID);
 294
 295         writel_relaxed(readl_relaxed(sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL)
 296                 & ~((1 << cid) | 1 << (cid + 16)),
 297                         sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL);
 298
 299         spin_lock_irqsave(&schan->lock, flags);
 300         list_splice_tail_init(&schan->active, &schan->free);
 301         list_splice_tail_init(&schan->queued, &schan->free);
 302         spin_unlock_irqrestore(&schan->lock, flags);
 303
 304         return 0;
 305 }
 306
 307 static int sirfsoc_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 308         unsigned long arg)
 309 {
 310         struct dma_slave_config *config;
 311         struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
 312
 313         switch (cmd) {
 314         case DMA_TERMINATE_ALL:
 315                 return sirfsoc_dma_terminate_all(schan);
 316         case DMA_SLAVE_CONFIG:
 317                 config = (struct dma_slave_config *)arg;
 318                 return sirfsoc_dma_slave_config(schan, config);
 319
 320         default:
 321                 break;
 322         }
 323
 324         return -ENOSYS;
 325 }
 326
 327 /* Alloc channel resources */
 328 static int sirfsoc_dma_alloc_chan_resources(struct dma_chan *chan)
 329 {
 330         struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(chan);
 331         struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
 332         struct sirfsoc_dma_desc *sdesc;
 333         unsigned long flags;
 334         LIST_HEAD(descs);
 335         int i;
 336
 337         /* Alloc descriptors for this channel */
 338         for (i = 0; i < SIRFSOC_DMA_DESCRIPTORS; i++) {
 339                 sdesc = kzalloc(sizeof(*sdesc), GFP_KERNEL);
 340                 if (!sdesc) {
 341                         dev_notice(sdma->dma.dev, "Memory allocation error. "
 342                                 "Allocated only %u descriptors\n", i);
 343                         break;
 344                 }
 345
 346                 dma_async_tx_descriptor_init(&sdesc->desc, chan);
 347                 sdesc->desc.flags = DMA_CTRL_ACK;
 348                 sdesc->desc.tx_submit = sirfsoc_dma_tx_submit;
 349
 350                 list_add_tail(&sdesc->node, &descs);
 351         }
 352
 353         /* Return error only if no descriptors were allocated */
 354         if (i == 0)
 355                 return -ENOMEM;
 356
 357         spin_lock_irqsave(&schan->lock, flags);
 358
 359         list_splice_tail_init(&descs, &schan->free);
 360         spin_unlock_irqrestore(&schan->lock, flags);
 361
 362         return i;
 363 }
 364
 365 /* Free channel resources */
 366 static void sirfsoc_dma_free_chan_resources(struct dma_chan *chan)
 367 {
 368         struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
 369         struct sirfsoc_dma_desc *sdesc, *tmp;
 370         unsigned long flags;
 371         LIST_HEAD(descs);
 372
 373         spin_lock_irqsave(&schan->lock, flags);
 374
 375         /* Channel must be idle */
 376         BUG_ON(!list_empty(&schan->prepared));
 377         BUG_ON(!list_empty(&schan->queued));
 378         BUG_ON(!list_empty(&schan->active));
 379         BUG_ON(!list_empty(&schan->completed));
 380
 381         /* Move data */
 382         list_splice_tail_init(&schan->free, &descs);
 383
 384         spin_unlock_irqrestore(&schan->lock, flags);
 385
 386         /* Free descriptors */
 387         list_for_each_entry_safe(sdesc, tmp, &descs, node)
 388                 kfree(sdesc);
 389 }
 390
 391 /* Send pending descriptor to hardware */
 392 static void sirfsoc_dma_issue_pending(struct dma_chan *chan)
 393 {
 394         struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
 395         unsigned long flags;
 396
 397         spin_lock_irqsave(&schan->lock, flags);
 398
 399         if (list_empty(&schan->active) && !list_empty(&schan->queued))
 400                 sirfsoc_dma_execute(schan);
 401
 402         spin_unlock_irqrestore(&schan->lock, flags);
 403 }
 404
 405 /* Check request completion status */
 406 static enum dma_status
 407 sirfsoc_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
 408         struct dma_tx_state *txstate)
 409 {
 410         struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
 411         unsigned long flags;
 412         enum dma_status ret;
 413
 414         spin_lock_irqsave(&schan->lock, flags);
 415         ret = dma_cookie_status(chan, cookie, txstate);
 416         spin_unlock_irqrestore(&schan->lock, flags);
 417
 418         return ret;
 419 }
 420
 421 static struct dma_async_tx_descriptor *sirfsoc_dma_prep_interleaved(
 422         struct dma_chan *chan, struct dma_interleaved_template *xt,
 423         unsigned long flags)
 424 {
 425         struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(chan);
 426         struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
 427         struct sirfsoc_dma_desc *sdesc = NULL;
 428         unsigned long iflags;
 429         int ret;
 430
 431         if ((xt->dir != DMA_MEM_TO_DEV) && (xt->dir != DMA_DEV_TO_MEM)) {
 432                 ret = -EINVAL;
 433                 goto err_dir;
 434         }
 435
 436         /* Get free descriptor */
 437         spin_lock_irqsave(&schan->lock, iflags);
 438         if (!list_empty(&schan->free)) {
 439                 sdesc = list_first_entry(&schan->free, struct sirfsoc_dma_desc,
 440                         node);
 441                 list_del(&sdesc->node);
 442         }
 443         spin_unlock_irqrestore(&schan->lock, iflags);
 444
 445         if (!sdesc) {
 446                 /* try to free completed descriptors */
 447                 sirfsoc_dma_process_completed(sdma);
 448                 ret = 0;
 449                 goto no_desc;
 450         }
 451
 452         /* Place descriptor in prepared list */
 453         spin_lock_irqsave(&schan->lock, iflags);
 454
 455         /*
 456          * Number of chunks in a frame can only be 1 for prima2
 457          * and ylen (number of frame - 1) must be at least 0
 458          */
 459         if ((xt->frame_size == 1) && (xt->numf > 0)) {
 460                 sdesc->cyclic = 0;
 461                 sdesc->xlen = xt->sgl[0].size / SIRFSOC_DMA_WORD_LEN;
 462                 sdesc->width = (xt->sgl[0].size + xt->sgl[0].icg) /
 463                                 SIRFSOC_DMA_WORD_LEN;
 464                 sdesc->ylen = xt->numf - 1;
 465                 if (xt->dir == DMA_MEM_TO_DEV) {
 466                         sdesc->addr = xt->src_start;
 467                         sdesc->dir = 1;
 468                 } else {
 469                         sdesc->addr = xt->dst_start;
 470                         sdesc->dir = 0;
 471                 }
 472
 473                 list_add_tail(&sdesc->node, &schan->prepared);
 474         } else {
 475                 pr_err("sirfsoc DMA Invalid xfer\n");
 476                 ret = -EINVAL;
 477                 goto err_xfer;
 478         }
 479         spin_unlock_irqrestore(&schan->lock, iflags);
 480
 481         return &sdesc->desc;
 482 err_xfer:
 483         spin_unlock_irqrestore(&schan->lock, iflags);
 484 no_desc:
 485 err_dir:
 486         return ERR_PTR(ret);
 487 }
 488
 489 static struct dma_async_tx_descriptor *
 490 sirfsoc_dma_prep_cyclic(struct dma_chan *chan, dma_addr_t addr,
 491         size_t buf_len, size_t period_len,
 492         enum dma_transfer_direction direction, unsigned long flags, void *context)
 493 {
 494         struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
 495         struct sirfsoc_dma_desc *sdesc = NULL;
 496         unsigned long iflags;
 497
 498         /*
 499          * we only support cycle transfer with 2 period
 500          * If the X-length is set to 0, it would be the loop mode.
 501          * The DMA address keeps increasing until reaching the end of a loop
 502          * area whose size is defined by (DMA_WIDTH x (Y_LENGTH + 1)). Then
 503          * the DMA address goes back to the beginning of this area.
 504          * In loop mode, the DMA data region is divided into two parts, BUFA
 505          * and BUFB. DMA controller generates interrupts twice in each loop:
 506          * when the DMA address reaches the end of BUFA or the end of the
 507          * BUFB
 508          */
 509         if (buf_len !=  2 * period_len)
 510                 return ERR_PTR(-EINVAL);
 511
 512         /* Get free descriptor */
 513         spin_lock_irqsave(&schan->lock, iflags);
 514         if (!list_empty(&schan->free)) {
 515                 sdesc = list_first_entry(&schan->free, struct sirfsoc_dma_desc,
 516                         node);
 517                 list_del(&sdesc->node);
 518         }
 519         spin_unlock_irqrestore(&schan->lock, iflags);
 520
 521         if (!sdesc)
 522                 return 0;
 523
 524         /* Place descriptor in prepared list */
 525         spin_lock_irqsave(&schan->lock, iflags);
 526         sdesc->addr = addr;
 527         sdesc->cyclic = 1;
 528         sdesc->xlen = 0;
 529         sdesc->ylen = buf_len / SIRFSOC_DMA_WORD_LEN - 1;
 530         sdesc->width = 1;
 531         list_add_tail(&sdesc->node, &schan->prepared);
 532         spin_unlock_irqrestore(&schan->lock, iflags);
 533
 534         return &sdesc->desc;
 535 }
 536
 537 /*
 538  * The DMA controller consists of 16 independent DMA channels.
 539  * Each channel is allocated to a different function
 540  */
 541 bool sirfsoc_dma_filter_id(struct dma_chan *chan, void *chan_id)
 542 {
 543         unsigned int ch_nr = (unsigned int) chan_id;
 544
 545         if (ch_nr == chan->chan_id +
 546                 chan->device->dev_id * SIRFSOC_DMA_CHANNELS)
 547                 return true;
 548
 549         return false;
 550 }
 551 EXPORT_SYMBOL(sirfsoc_dma_filter_id);
 552
 553 static int __devinit sirfsoc_dma_probe(struct platform_device *op)
 554 {
 555         struct device_node *dn = op->dev.of_node;
 556         struct device *dev = &op->dev;
 557         struct dma_device *dma;
 558         struct sirfsoc_dma *sdma;
 559         struct sirfsoc_dma_chan *schan;
 560         struct resource res;
 561         ulong regs_start, regs_size;
 562         u32 id;
 563         int ret, i;
 564
 565         sdma = devm_kzalloc(dev, sizeof(*sdma), GFP_KERNEL);
 566         if (!sdma) {
 567                 dev_err(dev, "Memory exhausted!\n");
 568                 return -ENOMEM;
 569         }
 570
 571         if (of_property_read_u32(dn, "cell-index", &id)) {
 572                 dev_err(dev, "Fail to get DMAC index\n");
 573                 return -ENODEV;
 574         }
 575
 576         sdma->irq = irq_of_parse_and_map(dn, 0);
 577         if (sdma->irq == NO_IRQ) {
 578                 dev_err(dev, "Error mapping IRQ!\n");
 579                 return -EINVAL;
 580         }
 581
 582         ret = of_address_to_resource(dn, 0, &res);
 583         if (ret) {
 584                 dev_err(dev, "Error parsing memory region!\n");
 585                 goto irq_dispose;
 586         }
 587
 588         regs_start = res.start;
 589         regs_size = resource_size(&res);
 590
 591         sdma->base = devm_ioremap(dev, regs_start, regs_size);
 592         if (!sdma->base) {
 593                 dev_err(dev, "Error mapping memory region!\n");
 594                 ret = -ENOMEM;
 595                 goto irq_dispose;
 596         }
 597
 598         ret = request_irq(sdma->irq, &sirfsoc_dma_irq, 0, DRV_NAME, sdma);
 599         if (ret) {
 600                 dev_err(dev, "Error requesting IRQ!\n");
 601                 ret = -EINVAL;
 602                 goto irq_dispose;
 603         }
 604
 605         dma = &sdma->dma;
 606         dma->dev = dev;
 607         dma->chancnt = SIRFSOC_DMA_CHANNELS;
 608
 609         dma->device_alloc_chan_resources = sirfsoc_dma_alloc_chan_resources;
 610         dma->device_free_chan_resources = sirfsoc_dma_free_chan_resources;
 611         dma->device_issue_pending = sirfsoc_dma_issue_pending;
 612         dma->device_control = sirfsoc_dma_control;
 613         dma->device_tx_status = sirfsoc_dma_tx_status;
 614         dma->device_prep_interleaved_dma = sirfsoc_dma_prep_interleaved;
 615         dma->device_prep_dma_cyclic = sirfsoc_dma_prep_cyclic;
 616
 617         INIT_LIST_HEAD(&dma->channels);
 618         dma_cap_set(DMA_SLAVE, dma->cap_mask);
 619         dma_cap_set(DMA_CYCLIC, dma->cap_mask);
 620         dma_cap_set(DMA_INTERLEAVE, dma->cap_mask);
 621         dma_cap_set(DMA_PRIVATE, dma->cap_mask);
 622
 623         for (i = 0; i < dma->chancnt; i++) {
 624                 schan = &sdma->channels[i];
 625
 626                 schan->chan.device = dma;
 627                 dma_cookie_init(&schan->chan);
 628
 629                 INIT_LIST_HEAD(&schan->free);
 630                 INIT_LIST_HEAD(&schan->prepared);
 631                 INIT_LIST_HEAD(&schan->queued);
 632                 INIT_LIST_HEAD(&schan->active);
 633                 INIT_LIST_HEAD(&schan->completed);
 634
 635                 spin_lock_init(&schan->lock);
 636                 list_add_tail(&schan->chan.device_node, &dma->channels);
 637         }
 638
 639         tasklet_init(&sdma->tasklet, sirfsoc_dma_tasklet, (unsigned long)sdma);
 640
 641         /* Register DMA engine */
 642         dev_set_drvdata(dev, sdma);
 643         ret = dma_async_device_register(dma);
 644         if (ret)
 645                 goto free_irq;
 646
 647         dev_info(dev, "initialized SIRFSOC DMAC driver\n");
 648
 649         return 0;
 650
 651 free_irq:
 652         free_irq(sdma->irq, sdma);
 653 irq_dispose:
 654         irq_dispose_mapping(sdma->irq);
 655         return ret;
 656 }
 657
 658 static int __devexit sirfsoc_dma_remove(struct platform_device *op)
 659 {
 660         struct device *dev = &op->dev;
 661         struct sirfsoc_dma *sdma = dev_get_drvdata(dev);
 662
 663         dma_async_device_unregister(&sdma->dma);
 664         free_irq(sdma->irq, sdma);
 665         irq_dispose_mapping(sdma->irq);
 666         return 0;
 667 }
 668
 669 static struct of_device_id sirfsoc_dma_match[] = {
 670         { .compatible = "sirf,prima2-dmac", },
 671         {},
 672 };
 673
 674 static struct platform_driver sirfsoc_dma_driver = {
 675         .probe          = sirfsoc_dma_probe,
 676         .remove         = __devexit_p(sirfsoc_dma_remove),
 677         .driver = {
 678                 .name = DRV_NAME,
 679                 .owner = THIS_MODULE,
 680                 .of_match_table = sirfsoc_dma_match,
 681         },
 682 };
 683
 684 module_platform_driver(sirfsoc_dma_driver);
 685
 686 MODULE_AUTHOR("Rongjun Ying <rongjun.ying@csr.com>, "
 687         "Barry Song <baohua.song@csr.com>");
 688 MODULE_DESCRIPTION("SIRFSOC DMA control driver");
 689 MODULE_LICENSE("GPL v2");