drivers/dma/omap-dma.c

   1 /*
   2  * OMAP DMAengine support
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8 #include <linux/dmaengine.h>
   9 #include <linux/dma-mapping.h>
  10 #include <linux/err.h>
  11 #include <linux/init.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/list.h>
  14 #include <linux/module.h>
  15 #include <linux/omap-dma.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/slab.h>
  18 #include <linux/spinlock.h>
  19
  20 #include "virt-dma.h"
  21
  22 #include <plat-omap/dma-omap.h>
  23
  24 struct omap_dmadev {
  25         struct dma_device ddev;
  26         spinlock_t lock;
  27         struct tasklet_struct task;
  28         struct list_head pending;
  29 };
  30
  31 struct omap_chan {
  32         struct virt_dma_chan vc;
  33         struct list_head node;
  34
  35         struct dma_slave_config cfg;
  36         unsigned dma_sig;
  37         bool cyclic;
  38         bool paused;
  39
  40         int dma_ch;
  41         struct omap_desc *desc;
  42         unsigned sgidx;
  43 };
  44
  45 struct omap_sg {
  46         dma_addr_t addr;
  47         uint32_t en;            /* number of elements (24-bit) */
  48         uint32_t fn;            /* number of frames (16-bit) */
  49 };
  50
  51 struct omap_desc {
  52         struct virt_dma_desc vd;
  53         enum dma_transfer_direction dir;
  54         dma_addr_t dev_addr;
  55
  56         int16_t fi;             /* for OMAP_DMA_SYNC_PACKET */
  57         uint8_t es;             /* OMAP_DMA_DATA_TYPE_xxx */
  58         uint8_t sync_mode;      /* OMAP_DMA_SYNC_xxx */
  59         uint8_t sync_type;      /* OMAP_DMA_xxx_SYNC* */
  60         uint8_t periph_port;    /* Peripheral port */
  61
  62         unsigned sglen;
  63         struct omap_sg sg[0];
  64 };
  65
  66 static const unsigned es_bytes[] = {
  67         [OMAP_DMA_DATA_TYPE_S8] = 1,
  68         [OMAP_DMA_DATA_TYPE_S16] = 2,
  69         [OMAP_DMA_DATA_TYPE_S32] = 4,
  70 };
  71
  72 static inline struct omap_dmadev *to_omap_dma_dev(struct dma_device *d)
  73 {
  74         return container_of(d, struct omap_dmadev, ddev);
  75 }
  76
  77 static inline struct omap_chan *to_omap_dma_chan(struct dma_chan *c)
  78 {
  79         return container_of(c, struct omap_chan, vc.chan);
  80 }
  81
  82 static inline struct omap_desc *to_omap_dma_desc(struct dma_async_tx_descriptor *t)
  83 {
  84         return container_of(t, struct omap_desc, vd.tx);
  85 }
  86
  87 static void omap_dma_desc_free(struct virt_dma_desc *vd)
  88 {
  89         kfree(container_of(vd, struct omap_desc, vd));
  90 }
  91
  92 static void omap_dma_start_sg(struct omap_chan *c, struct omap_desc *d,
  93         unsigned idx)
  94 {
  95         struct omap_sg *sg = d->sg + idx;
  96
  97         if (d->dir == DMA_DEV_TO_MEM)
  98                 omap_set_dma_dest_params(c->dma_ch, OMAP_DMA_PORT_EMIFF,
  99                         OMAP_DMA_AMODE_POST_INC, sg->addr, 0, 0);
 100         else
 101                 omap_set_dma_src_params(c->dma_ch, OMAP_DMA_PORT_EMIFF,
 102                         OMAP_DMA_AMODE_POST_INC, sg->addr, 0, 0);
 103
 104         omap_set_dma_transfer_params(c->dma_ch, d->es, sg->en, sg->fn,
 105                 d->sync_mode, c->dma_sig, d->sync_type);
 106
 107         omap_start_dma(c->dma_ch);
 108 }
 109
 110 static void omap_dma_start_desc(struct omap_chan *c)
 111 {
 112         struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
 113         struct omap_desc *d;
 114
 115         if (!vd) {
 116                 c->desc = NULL;
 117                 return;
 118         }
 119
 120         list_del(&vd->node);
 121
 122         c->desc = d = to_omap_dma_desc(&vd->tx);
 123         c->sgidx = 0;
 124
 125         if (d->dir == DMA_DEV_TO_MEM)
 126                 omap_set_dma_src_params(c->dma_ch, d->periph_port,
 127                         OMAP_DMA_AMODE_CONSTANT, d->dev_addr, 0, d->fi);
 128         else
 129                 omap_set_dma_dest_params(c->dma_ch, d->periph_port,
 130                         OMAP_DMA_AMODE_CONSTANT, d->dev_addr, 0, d->fi);
 131
 132         omap_dma_start_sg(c, d, 0);
 133 }
 134
 135 static void omap_dma_callback(int ch, u16 status, void *data)
 136 {
 137         struct omap_chan *c = data;
 138         struct omap_desc *d;
 139         unsigned long flags;
 140
 141         spin_lock_irqsave(&c->vc.lock, flags);
 142         d = c->desc;
 143         if (d) {
 144                 if (!c->cyclic) {
 145                         if (++c->sgidx < d->sglen) {
 146                                 omap_dma_start_sg(c, d, c->sgidx);
 147                         } else {
 148                                 omap_dma_start_desc(c);
 149                                 vchan_cookie_complete(&d->vd);
 150                         }
 151                 } else {
 152                         vchan_cyclic_callback(&d->vd);
 153                 }
 154         }
 155         spin_unlock_irqrestore(&c->vc.lock, flags);
 156 }
 157
 158 /*
 159  * This callback schedules all pending channels.  We could be more
 160  * clever here by postponing allocation of the real DMA channels to
 161  * this point, and freeing them when our virtual channel becomes idle.
 162  *
 163  * We would then need to deal with 'all channels in-use'
 164  */
 165 static void omap_dma_sched(unsigned long data)
 166 {
 167         struct omap_dmadev *d = (struct omap_dmadev *)data;
 168         LIST_HEAD(head);
 169
 170         spin_lock_irq(&d->lock);
 171         list_splice_tail_init(&d->pending, &head);
 172         spin_unlock_irq(&d->lock);
 173
 174         while (!list_empty(&head)) {
 175                 struct omap_chan *c = list_first_entry(&head,
 176                         struct omap_chan, node);
 177
 178                 spin_lock_irq(&c->vc.lock);
 179                 list_del_init(&c->node);
 180                 omap_dma_start_desc(c);
 181                 spin_unlock_irq(&c->vc.lock);
 182         }
 183 }
 184
 185 static int omap_dma_alloc_chan_resources(struct dma_chan *chan)
 186 {
 187         struct omap_chan *c = to_omap_dma_chan(chan);
 188
 189         dev_info(c->vc.chan.device->dev, "allocating channel for %u\n", c->dma_sig);
 190
 191         return omap_request_dma(c->dma_sig, "DMA engine",
 192                 omap_dma_callback, c, &c->dma_ch);
 193 }
 194
 195 static void omap_dma_free_chan_resources(struct dma_chan *chan)
 196 {
 197         struct omap_chan *c = to_omap_dma_chan(chan);
 198
 199         vchan_free_chan_resources(&c->vc);
 200         omap_free_dma(c->dma_ch);
 201
 202         dev_info(c->vc.chan.device->dev, "freeing channel for %u\n", c->dma_sig);
 203 }
 204
 205 static size_t omap_dma_sg_size(struct omap_sg *sg)
 206 {
 207         return sg->en * sg->fn;
 208 }
 209
 210 static size_t omap_dma_desc_size(struct omap_desc *d)
 211 {
 212         unsigned i;
 213         size_t size;
 214
 215         for (size = i = 0; i < d->sglen; i++)
 216                 size += omap_dma_sg_size(&d->sg[i]);
 217
 218         return size * es_bytes[d->es];
 219 }
 220
 221 static size_t omap_dma_desc_size_pos(struct omap_desc *d, dma_addr_t addr)
 222 {
 223         unsigned i;
 224         size_t size, es_size = es_bytes[d->es];
 225
 226         for (size = i = 0; i < d->sglen; i++) {
 227                 size_t this_size = omap_dma_sg_size(&d->sg[i]) * es_size;
 228
 229                 if (size)
 230                         size += this_size;
 231                 else if (addr >= d->sg[i].addr &&
 232                          addr < d->sg[i].addr + this_size)
 233                         size += d->sg[i].addr + this_size - addr;
 234         }
 235         return size;
 236 }
 237
 238 static enum dma_status omap_dma_tx_status(struct dma_chan *chan,
 239         dma_cookie_t cookie, struct dma_tx_state *txstate)
 240 {
 241         struct omap_chan *c = to_omap_dma_chan(chan);
 242         struct virt_dma_desc *vd;
 243         enum dma_status ret;
 244         unsigned long flags;
 245
 246         ret = dma_cookie_status(chan, cookie, txstate);
 247         if (ret == DMA_SUCCESS || !txstate)
 248                 return ret;
 249
 250         spin_lock_irqsave(&c->vc.lock, flags);
 251         vd = vchan_find_desc(&c->vc, cookie);
 252         if (vd) {
 253                 txstate->residue = omap_dma_desc_size(to_omap_dma_desc(&vd->tx));
 254         } else if (c->desc && c->desc->vd.tx.cookie == cookie) {
 255                 struct omap_desc *d = c->desc;
 256                 dma_addr_t pos;
 257
 258                 if (d->dir == DMA_MEM_TO_DEV)
 259                         pos = omap_get_dma_src_pos(c->dma_ch);
 260                 else if (d->dir == DMA_DEV_TO_MEM)
 261                         pos = omap_get_dma_dst_pos(c->dma_ch);
 262                 else
 263                         pos = 0;
 264
 265                 txstate->residue = omap_dma_desc_size_pos(d, pos);
 266         } else {
 267                 txstate->residue = 0;
 268         }
 269         spin_unlock_irqrestore(&c->vc.lock, flags);
 270
 271         return ret;
 272 }
 273
 274 static void omap_dma_issue_pending(struct dma_chan *chan)
 275 {
 276         struct omap_chan *c = to_omap_dma_chan(chan);
 277         unsigned long flags;
 278
 279         spin_lock_irqsave(&c->vc.lock, flags);
 280         if (vchan_issue_pending(&c->vc) && !c->desc) {
 281                 struct omap_dmadev *d = to_omap_dma_dev(chan->device);
 282                 spin_lock(&d->lock);
 283                 if (list_empty(&c->node))
 284                         list_add_tail(&c->node, &d->pending);
 285                 spin_unlock(&d->lock);
 286                 tasklet_schedule(&d->task);
 287         }
 288         spin_unlock_irqrestore(&c->vc.lock, flags);
 289 }
 290
 291 static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
 292         struct dma_chan *chan, struct scatterlist *sgl, unsigned sglen,
 293         enum dma_transfer_direction dir, unsigned long tx_flags, void *context)
 294 {
 295         struct omap_chan *c = to_omap_dma_chan(chan);
 296         enum dma_slave_buswidth dev_width;
 297         struct scatterlist *sgent;
 298         struct omap_desc *d;
 299         dma_addr_t dev_addr;
 300         unsigned i, j = 0, es, en, frame_bytes, sync_type;
 301         u32 burst;
 302
 303         if (dir == DMA_DEV_TO_MEM) {
 304                 dev_addr = c->cfg.src_addr;
 305                 dev_width = c->cfg.src_addr_width;
 306                 burst = c->cfg.src_maxburst;
 307                 sync_type = OMAP_DMA_SRC_SYNC;
 308         } else if (dir == DMA_MEM_TO_DEV) {
 309                 dev_addr = c->cfg.dst_addr;
 310                 dev_width = c->cfg.dst_addr_width;
 311                 burst = c->cfg.dst_maxburst;
 312                 sync_type = OMAP_DMA_DST_SYNC;
 313         } else {
 314                 dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
 315                 return NULL;
 316         }
 317
 318         /* Bus width translates to the element size (ES) */
 319         switch (dev_width) {
 320         case DMA_SLAVE_BUSWIDTH_1_BYTE:
 321                 es = OMAP_DMA_DATA_TYPE_S8;
 322                 break;
 323         case DMA_SLAVE_BUSWIDTH_2_BYTES:
 324                 es = OMAP_DMA_DATA_TYPE_S16;
 325                 break;
 326         case DMA_SLAVE_BUSWIDTH_4_BYTES:
 327                 es = OMAP_DMA_DATA_TYPE_S32;
 328                 break;
 329         default: /* not reached */
 330                 return NULL;
 331         }
 332
 333         /* Now allocate and setup the descriptor. */
 334         d = kzalloc(sizeof(*d) + sglen * sizeof(d->sg[0]), GFP_ATOMIC);
 335         if (!d)
 336                 return NULL;
 337
 338         d->dir = dir;
 339         d->dev_addr = dev_addr;
 340         d->es = es;
 341         d->sync_mode = OMAP_DMA_SYNC_FRAME;
 342         d->sync_type = sync_type;
 343         d->periph_port = OMAP_DMA_PORT_TIPB;
 344
 345         /*
 346          * Build our scatterlist entries: each contains the address,
 347          * the number of elements (EN) in each frame, and the number of
 348          * frames (FN).  Number of bytes for this entry = ES * EN * FN.
 349          *
 350          * Burst size translates to number of elements with frame sync.
 351          * Note: DMA engine defines burst to be the number of dev-width
 352          * transfers.
 353          */
 354         en = burst;
 355         frame_bytes = es_bytes[es] * en;
 356         for_each_sg(sgl, sgent, sglen, i) {
 357                 d->sg[j].addr = sg_dma_address(sgent);
 358                 d->sg[j].en = en;
 359                 d->sg[j].fn = sg_dma_len(sgent) / frame_bytes;
 360                 j++;
 361         }
 362
 363         d->sglen = j;
 364
 365         return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
 366 }
 367
 368 static struct dma_async_tx_descriptor *omap_dma_prep_dma_cyclic(
 369         struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
 370         size_t period_len, enum dma_transfer_direction dir, unsigned long flags,
 371         void *context)
 372 {
 373         struct omap_chan *c = to_omap_dma_chan(chan);
 374         enum dma_slave_buswidth dev_width;
 375         struct omap_desc *d;
 376         dma_addr_t dev_addr;
 377         unsigned es, sync_type;
 378         u32 burst;
 379
 380         if (dir == DMA_DEV_TO_MEM) {
 381                 dev_addr = c->cfg.src_addr;
 382                 dev_width = c->cfg.src_addr_width;
 383                 burst = c->cfg.src_maxburst;
 384                 sync_type = OMAP_DMA_SRC_SYNC;
 385         } else if (dir == DMA_MEM_TO_DEV) {
 386                 dev_addr = c->cfg.dst_addr;
 387                 dev_width = c->cfg.dst_addr_width;
 388                 burst = c->cfg.dst_maxburst;
 389                 sync_type = OMAP_DMA_DST_SYNC;
 390         } else {
 391                 dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
 392                 return NULL;
 393         }
 394
 395         /* Bus width translates to the element size (ES) */
 396         switch (dev_width) {
 397         case DMA_SLAVE_BUSWIDTH_1_BYTE:
 398                 es = OMAP_DMA_DATA_TYPE_S8;
 399                 break;
 400         case DMA_SLAVE_BUSWIDTH_2_BYTES:
 401                 es = OMAP_DMA_DATA_TYPE_S16;
 402                 break;
 403         case DMA_SLAVE_BUSWIDTH_4_BYTES:
 404                 es = OMAP_DMA_DATA_TYPE_S32;
 405                 break;
 406         default: /* not reached */
 407                 return NULL;
 408         }
 409
 410         /* Now allocate and setup the descriptor. */
 411         d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC);
 412         if (!d)
 413                 return NULL;
 414
 415         d->dir = dir;
 416         d->dev_addr = dev_addr;
 417         d->fi = burst;
 418         d->es = es;
 419         if (burst)
 420                 d->sync_mode = OMAP_DMA_SYNC_PACKET;
 421         else
 422                 d->sync_mode = OMAP_DMA_SYNC_ELEMENT;
 423         d->sync_type = sync_type;
 424         d->periph_port = OMAP_DMA_PORT_MPUI;
 425         d->sg[0].addr = buf_addr;
 426         d->sg[0].en = period_len / es_bytes[es];
 427         d->sg[0].fn = buf_len / period_len;
 428         d->sglen = 1;
 429
 430         if (!c->cyclic) {
 431                 c->cyclic = true;
 432                 omap_dma_link_lch(c->dma_ch, c->dma_ch);
 433
 434                 if (flags & DMA_PREP_INTERRUPT)
 435                         omap_enable_dma_irq(c->dma_ch, OMAP_DMA_FRAME_IRQ);
 436
 437                 omap_disable_dma_irq(c->dma_ch, OMAP_DMA_BLOCK_IRQ);
 438         }
 439
 440         if (dma_omap2plus()) {
 441                 omap_set_dma_src_burst_mode(c->dma_ch, OMAP_DMA_DATA_BURST_16);
 442                 omap_set_dma_dest_burst_mode(c->dma_ch, OMAP_DMA_DATA_BURST_16);
 443         }
 444
 445         return vchan_tx_prep(&c->vc, &d->vd, flags);
 446 }
 447
 448 static int omap_dma_slave_config(struct omap_chan *c, struct dma_slave_config *cfg)
 449 {
 450         if (cfg->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
 451             cfg->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
 452                 return -EINVAL;
 453
 454         memcpy(&c->cfg, cfg, sizeof(c->cfg));
 455
 456         return 0;
 457 }
 458
 459 static int omap_dma_terminate_all(struct omap_chan *c)
 460 {
 461         struct omap_dmadev *d = to_omap_dma_dev(c->vc.chan.device);
 462         unsigned long flags;
 463         LIST_HEAD(head);
 464
 465         spin_lock_irqsave(&c->vc.lock, flags);
 466
 467         /* Prevent this channel being scheduled */
 468         spin_lock(&d->lock);
 469         list_del_init(&c->node);
 470         spin_unlock(&d->lock);
 471
 472         /*
 473          * Stop DMA activity: we assume the callback will not be called
 474          * after omap_stop_dma() returns (even if it does, it will see
 475          * c->desc is NULL and exit.)
 476          */
 477         if (c->desc) {
 478                 c->desc = NULL;
 479                 /* Avoid stopping the dma twice */
 480                 if (!c->paused)
 481                         omap_stop_dma(c->dma_ch);
 482         }
 483
 484         if (c->cyclic) {
 485                 c->cyclic = false;
 486                 c->paused = false;
 487                 omap_dma_unlink_lch(c->dma_ch, c->dma_ch);
 488         }
 489
 490         vchan_get_all_descriptors(&c->vc, &head);
 491         spin_unlock_irqrestore(&c->vc.lock, flags);
 492         vchan_dma_desc_free_list(&c->vc, &head);
 493
 494         return 0;
 495 }
 496
 497 static int omap_dma_pause(struct omap_chan *c)
 498 {
 499         /* Pause/Resume only allowed with cyclic mode */
 500         if (!c->cyclic)
 501                 return -EINVAL;
 502
 503         if (!c->paused) {
 504                 omap_stop_dma(c->dma_ch);
 505                 c->paused = true;
 506         }
 507
 508         return 0;
 509 }
 510
 511 static int omap_dma_resume(struct omap_chan *c)
 512 {
 513         /* Pause/Resume only allowed with cyclic mode */
 514         if (!c->cyclic)
 515                 return -EINVAL;
 516
 517         if (c->paused) {
 518                 omap_start_dma(c->dma_ch);
 519                 c->paused = false;
 520         }
 521
 522         return 0;
 523 }
 524
 525 static int omap_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 526         unsigned long arg)
 527 {
 528         struct omap_chan *c = to_omap_dma_chan(chan);
 529         int ret;
 530
 531         switch (cmd) {
 532         case DMA_SLAVE_CONFIG:
 533                 ret = omap_dma_slave_config(c, (struct dma_slave_config *)arg);
 534                 break;
 535
 536         case DMA_TERMINATE_ALL:
 537                 ret = omap_dma_terminate_all(c);
 538                 break;
 539
 540         case DMA_PAUSE:
 541                 ret = omap_dma_pause(c);
 542                 break;
 543
 544         case DMA_RESUME:
 545                 ret = omap_dma_resume(c);
 546                 break;
 547
 548         default:
 549                 ret = -ENXIO;
 550                 break;
 551         }
 552
 553         return ret;
 554 }
 555
 556 static int omap_dma_chan_init(struct omap_dmadev *od, int dma_sig)
 557 {
 558         struct omap_chan *c;
 559
 560         c = kzalloc(sizeof(*c), GFP_KERNEL);
 561         if (!c)
 562                 return -ENOMEM;
 563
 564         c->dma_sig = dma_sig;
 565         c->vc.desc_free = omap_dma_desc_free;
 566         vchan_init(&c->vc, &od->ddev);
 567         INIT_LIST_HEAD(&c->node);
 568
 569         od->ddev.chancnt++;
 570
 571         return 0;
 572 }
 573
 574 static void omap_dma_free(struct omap_dmadev *od)
 575 {
 576         tasklet_kill(&od->task);
 577         while (!list_empty(&od->ddev.channels)) {
 578                 struct omap_chan *c = list_first_entry(&od->ddev.channels,
 579                         struct omap_chan, vc.chan.device_node);
 580
 581                 list_del(&c->vc.chan.device_node);
 582                 tasklet_kill(&c->vc.task);
 583                 kfree(c);
 584         }
 585         kfree(od);
 586 }
 587
 588 static int omap_dma_probe(struct platform_device *pdev)
 589 {
 590         struct omap_dmadev *od;
 591         int rc, i;
 592
 593         od = kzalloc(sizeof(*od), GFP_KERNEL);
 594         if (!od)
 595                 return -ENOMEM;
 596
 597         dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
 598         dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask);
 599         od->ddev.device_alloc_chan_resources = omap_dma_alloc_chan_resources;
 600         od->ddev.device_free_chan_resources = omap_dma_free_chan_resources;
 601         od->ddev.device_tx_status = omap_dma_tx_status;
 602         od->ddev.device_issue_pending = omap_dma_issue_pending;
 603         od->ddev.device_prep_slave_sg = omap_dma_prep_slave_sg;
 604         od->ddev.device_prep_dma_cyclic = omap_dma_prep_dma_cyclic;
 605         od->ddev.device_control = omap_dma_control;
 606         od->ddev.dev = &pdev->dev;
 607         INIT_LIST_HEAD(&od->ddev.channels);
 608         INIT_LIST_HEAD(&od->pending);
 609         spin_lock_init(&od->lock);
 610
 611         tasklet_init(&od->task, omap_dma_sched, (unsigned long)od);
 612
 613         for (i = 0; i < 127; i++) {
 614                 rc = omap_dma_chan_init(od, i);
 615                 if (rc) {
 616                         omap_dma_free(od);
 617                         return rc;
 618                 }
 619         }
 620
 621         rc = dma_async_device_register(&od->ddev);
 622         if (rc) {
 623                 pr_warn("OMAP-DMA: failed to register slave DMA engine device: %d\n",
 624                         rc);
 625                 omap_dma_free(od);
 626         } else {
 627                 platform_set_drvdata(pdev, od);
 628         }
 629
 630         dev_info(&pdev->dev, "OMAP DMA engine driver\n");
 631
 632         return rc;
 633 }
 634
 635 static int omap_dma_remove(struct platform_device *pdev)
 636 {
 637         struct omap_dmadev *od = platform_get_drvdata(pdev);
 638
 639         dma_async_device_unregister(&od->ddev);
 640         omap_dma_free(od);
 641
 642         return 0;
 643 }
 644
 645 static struct platform_driver omap_dma_driver = {
 646         .probe  = omap_dma_probe,
 647         .remove = omap_dma_remove,
 648         .driver = {
 649                 .name = "omap-dma-engine",
 650                 .owner = THIS_MODULE,
 651         },
 652 };
 653
 654 bool omap_dma_filter_fn(struct dma_chan *chan, void *param)
 655 {
 656         if (chan->device->dev->driver == &omap_dma_driver.driver) {
 657                 struct omap_chan *c = to_omap_dma_chan(chan);
 658                 unsigned req = *(unsigned *)param;
 659
 660                 return req == c->dma_sig;
 661         }
 662         return false;
 663 }
 664 EXPORT_SYMBOL_GPL(omap_dma_filter_fn);
 665
 666 static struct platform_device *pdev;
 667
 668 static const struct platform_device_info omap_dma_dev_info = {
 669         .name = "omap-dma-engine",
 670         .id = -1,
 671         .dma_mask = DMA_BIT_MASK(32),
 672 };
 673
 674 static int omap_dma_init(void)
 675 {
 676         int rc = platform_driver_register(&omap_dma_driver);
 677
 678         if (rc == 0) {
 679                 pdev = platform_device_register_full(&omap_dma_dev_info);
 680                 if (IS_ERR(pdev)) {
 681                         platform_driver_unregister(&omap_dma_driver);
 682                         rc = PTR_ERR(pdev);
 683                 }
 684         }
 685         return rc;
 686 }
 687 subsys_initcall(omap_dma_init);
 688
 689 static void __exit omap_dma_exit(void)
 690 {
 691         platform_device_unregister(pdev);
 692         platform_driver_unregister(&omap_dma_driver);
 693 }
 694 module_exit(omap_dma_exit);
 695
 696 MODULE_AUTHOR("Russell King");
 697 MODULE_LICENSE("GPL");