drivers/dma/edma.c

   1 /*
   2  * TI EDMA DMA engine driver
   3  *
   4  * Copyright 2012 Texas Instruments
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation version 2.
   9  *
  10  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  11  * kind, whether express or implied; without even the implied warranty
  12  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/dmaengine.h>
  17 #include <linux/dma-mapping.h>
  18 #include <linux/err.h>
  19 #include <linux/init.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/list.h>
  22 #include <linux/module.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/slab.h>
  25 #include <linux/spinlock.h>
  26
  27 #include <mach/edma.h>
  28
  29 #include "dmaengine.h"
  30 #include "virt-dma.h"
  31
  32 /*
  33  * This will go away when the private EDMA API is folded
  34  * into this driver and the platform device(s) are
  35  * instantiated in the arch code. We can only get away
  36  * with this simplification because DA8XX may not be built
  37  * in the same kernel image with other DaVinci parts. This
  38  * avoids having to sprinkle dmaengine driver platform devices
  39  * and data throughout all the existing board files.
  40  */
  41 #ifdef CONFIG_ARCH_DAVINCI_DA8XX
  42 #define EDMA_CTLRS      2
  43 #define EDMA_CHANS      32
  44 #else
  45 #define EDMA_CTLRS      1
  46 #define EDMA_CHANS      64
  47 #endif /* CONFIG_ARCH_DAVINCI_DA8XX */
  48
  49 /* Max of 16 segments per channel to conserve PaRAM slots */
  50 #define MAX_NR_SG               16
  51 #define EDMA_MAX_SLOTS          MAX_NR_SG
  52 #define EDMA_DESCRIPTORS        16
  53
  54 struct edma_desc {
  55         struct virt_dma_desc            vdesc;
  56         struct list_head                node;
  57         int                             absync;
  58         int                             pset_nr;
  59         struct edmacc_param             pset[0];
  60 };
  61
  62 struct edma_cc;
  63
  64 struct edma_chan {
  65         struct virt_dma_chan            vchan;
  66         struct list_head                node;
  67         struct edma_desc                *edesc;
  68         struct edma_cc                  *ecc;
  69         int                             ch_num;
  70         bool                            alloced;
  71         int                             slot[EDMA_MAX_SLOTS];
  72         dma_addr_t                      addr;
  73         int                             addr_width;
  74         int                             maxburst;
  75 };
  76
  77 struct edma_cc {
  78         int                             ctlr;
  79         struct dma_device               dma_slave;
  80         struct edma_chan                slave_chans[EDMA_CHANS];
  81         int                             num_slave_chans;
  82         int                             dummy_slot;
  83 };
  84
  85 static inline struct edma_cc *to_edma_cc(struct dma_device *d)
  86 {
  87         return container_of(d, struct edma_cc, dma_slave);
  88 }
  89
  90 static inline struct edma_chan *to_edma_chan(struct dma_chan *c)
  91 {
  92         return container_of(c, struct edma_chan, vchan.chan);
  93 }
  94
  95 static inline struct edma_desc
  96 *to_edma_desc(struct dma_async_tx_descriptor *tx)
  97 {
  98         return container_of(tx, struct edma_desc, vdesc.tx);
  99 }
 100
 101 static void edma_desc_free(struct virt_dma_desc *vdesc)
 102 {
 103         kfree(container_of(vdesc, struct edma_desc, vdesc));
 104 }
 105
 106 /* Dispatch a queued descriptor to the controller (caller holds lock) */
 107 static void edma_execute(struct edma_chan *echan)
 108 {
 109         struct virt_dma_desc *vdesc = vchan_next_desc(&echan->vchan);
 110         struct edma_desc *edesc;
 111         int i;
 112
 113         if (!vdesc) {
 114                 echan->edesc = NULL;
 115                 return;
 116         }
 117
 118         list_del(&vdesc->node);
 119
 120         echan->edesc = edesc = to_edma_desc(&vdesc->tx);
 121
 122         /* Write descriptor PaRAM set(s) */
 123         for (i = 0; i < edesc->pset_nr; i++) {
 124                 edma_write_slot(echan->slot[i], &edesc->pset[i]);
 125                 dev_dbg(echan->vchan.chan.device->dev,
 126                         "\n pset[%d]:\n"
 127                         "  chnum\t%d\n"
 128                         "  slot\t%d\n"
 129                         "  opt\t%08x\n"
 130                         "  src\t%08x\n"
 131                         "  dst\t%08x\n"
 132                         "  abcnt\t%08x\n"
 133                         "  ccnt\t%08x\n"
 134                         "  bidx\t%08x\n"
 135                         "  cidx\t%08x\n"
 136                         "  lkrld\t%08x\n",
 137                         i, echan->ch_num, echan->slot[i],
 138                         edesc->pset[i].opt,
 139                         edesc->pset[i].src,
 140                         edesc->pset[i].dst,
 141                         edesc->pset[i].a_b_cnt,
 142                         edesc->pset[i].ccnt,
 143                         edesc->pset[i].src_dst_bidx,
 144                         edesc->pset[i].src_dst_cidx,
 145                         edesc->pset[i].link_bcntrld);
 146                 /* Link to the previous slot if not the last set */
 147                 if (i != (edesc->pset_nr - 1))
 148                         edma_link(echan->slot[i], echan->slot[i+1]);
 149                 /* Final pset links to the dummy pset */
 150                 else
 151                         edma_link(echan->slot[i], echan->ecc->dummy_slot);
 152         }
 153
 154         edma_start(echan->ch_num);
 155 }
 156
 157 static int edma_terminate_all(struct edma_chan *echan)
 158 {
 159         unsigned long flags;
 160         LIST_HEAD(head);
 161
 162         spin_lock_irqsave(&echan->vchan.lock, flags);
 163
 164         /*
 165          * Stop DMA activity: we assume the callback will not be called
 166          * after edma_dma() returns (even if it does, it will see
 167          * echan->edesc is NULL and exit.)
 168          */
 169         if (echan->edesc) {
 170                 echan->edesc = NULL;
 171                 edma_stop(echan->ch_num);
 172         }
 173
 174         vchan_get_all_descriptors(&echan->vchan, &head);
 175         spin_unlock_irqrestore(&echan->vchan.lock, flags);
 176         vchan_dma_desc_free_list(&echan->vchan, &head);
 177
 178         return 0;
 179 }
 180
 181
 182 static int edma_slave_config(struct edma_chan *echan,
 183         struct dma_slave_config *config)
 184 {
 185         if ((config->src_addr_width > DMA_SLAVE_BUSWIDTH_4_BYTES) ||
 186             (config->dst_addr_width > DMA_SLAVE_BUSWIDTH_4_BYTES))
 187                 return -EINVAL;
 188
 189         if (config->direction == DMA_MEM_TO_DEV) {
 190                 if (config->dst_addr)
 191                         echan->addr = config->dst_addr;
 192                 if (config->dst_addr_width)
 193                         echan->addr_width = config->dst_addr_width;
 194                 if (config->dst_maxburst)
 195                         echan->maxburst = config->dst_maxburst;
 196         } else if (config->direction == DMA_DEV_TO_MEM) {
 197                 if (config->src_addr)
 198                         echan->addr = config->src_addr;
 199                 if (config->src_addr_width)
 200                         echan->addr_width = config->src_addr_width;
 201                 if (config->src_maxburst)
 202                         echan->maxburst = config->src_maxburst;
 203         }
 204
 205         return 0;
 206 }
 207
 208 static int edma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 209                         unsigned long arg)
 210 {
 211         int ret = 0;
 212         struct dma_slave_config *config;
 213         struct edma_chan *echan = to_edma_chan(chan);
 214
 215         switch (cmd) {
 216         case DMA_TERMINATE_ALL:
 217                 edma_terminate_all(echan);
 218                 break;
 219         case DMA_SLAVE_CONFIG:
 220                 config = (struct dma_slave_config *)arg;
 221                 ret = edma_slave_config(echan, config);
 222                 break;
 223         default:
 224                 ret = -ENOSYS;
 225         }
 226
 227         return ret;
 228 }
 229
 230 static struct dma_async_tx_descriptor *edma_prep_slave_sg(
 231         struct dma_chan *chan, struct scatterlist *sgl,
 232         unsigned int sg_len, enum dma_transfer_direction direction,
 233         unsigned long tx_flags, void *context)
 234 {
 235         struct edma_chan *echan = to_edma_chan(chan);
 236         struct device *dev = chan->device->dev;
 237         struct edma_desc *edesc;
 238         struct scatterlist *sg;
 239         int i;
 240         int acnt, bcnt, ccnt, src, dst, cidx;
 241         int src_bidx, dst_bidx, src_cidx, dst_cidx;
 242
 243         if (unlikely(!echan || !sgl || !sg_len))
 244                 return NULL;
 245
 246         if (echan->addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED) {
 247                 dev_err(dev, "Undefined slave buswidth\n");
 248                 return NULL;
 249         }
 250
 251         if (sg_len > MAX_NR_SG) {
 252                 dev_err(dev, "Exceeded max SG segments %d > %d\n",
 253                         sg_len, MAX_NR_SG);
 254                 return NULL;
 255         }
 256
 257         edesc = kzalloc(sizeof(*edesc) + sg_len *
 258                 sizeof(edesc->pset[0]), GFP_ATOMIC);
 259         if (!edesc) {
 260                 dev_dbg(dev, "Failed to allocate a descriptor\n");
 261                 return NULL;
 262         }
 263
 264         edesc->pset_nr = sg_len;
 265
 266         for_each_sg(sgl, sg, sg_len, i) {
 267                 /* Allocate a PaRAM slot, if needed */
 268                 if (echan->slot[i] < 0) {
 269                         echan->slot[i] =
 270                                 edma_alloc_slot(EDMA_CTLR(echan->ch_num),
 271                                                 EDMA_SLOT_ANY);
 272                         if (echan->slot[i] < 0) {
 273                                 dev_err(dev, "Failed to allocate slot\n");
 274                                 return NULL;
 275                         }
 276                 }
 277
 278                 acnt = echan->addr_width;
 279
 280                 /*
 281                  * If the maxburst is equal to the fifo width, use
 282                  * A-synced transfers. This allows for large contiguous
 283                  * buffer transfers using only one PaRAM set.
 284                  */
 285                 if (echan->maxburst == 1) {
 286                         edesc->absync = false;
 287                         ccnt = sg_dma_len(sg) / acnt / (SZ_64K - 1);
 288                         bcnt = sg_dma_len(sg) / acnt - ccnt * (SZ_64K - 1);
 289                         if (bcnt)
 290                                 ccnt++;
 291                         else
 292                                 bcnt = SZ_64K - 1;
 293                         cidx = acnt;
 294                 /*
 295                  * If maxburst is greater than the fifo address_width,
 296                  * use AB-synced transfers where A count is the fifo
 297                  * address_width and B count is the maxburst. In this
 298                  * case, we are limited to transfers of C count frames
 299                  * of (address_width * maxburst) where C count is limited
 300                  * to SZ_64K-1. This places an upper bound on the length
 301                  * of an SG segment that can be handled.
 302                  */
 303                 } else {
 304                         edesc->absync = true;
 305                         bcnt = echan->maxburst;
 306                         ccnt = sg_dma_len(sg) / (acnt * bcnt);
 307                         if (ccnt > (SZ_64K - 1)) {
 308                                 dev_err(dev, "Exceeded max SG segment size\n");
 309                                 return NULL;
 310                         }
 311                         cidx = acnt * bcnt;
 312                 }
 313
 314                 if (direction == DMA_MEM_TO_DEV) {
 315                         src = sg_dma_address(sg);
 316                         dst = echan->addr;
 317                         src_bidx = acnt;
 318                         src_cidx = cidx;
 319                         dst_bidx = 0;
 320                         dst_cidx = 0;
 321                 } else {
 322                         src = echan->addr;
 323                         dst = sg_dma_address(sg);
 324                         src_bidx = 0;
 325                         src_cidx = 0;
 326                         dst_bidx = acnt;
 327                         dst_cidx = cidx;
 328                 }
 329
 330                 edesc->pset[i].opt = EDMA_TCC(EDMA_CHAN_SLOT(echan->ch_num));
 331                 /* Configure A or AB synchronized transfers */
 332                 if (edesc->absync)
 333                         edesc->pset[i].opt |= SYNCDIM;
 334                 /* If this is the last set, enable completion interrupt flag */
 335                 if (i == sg_len - 1)
 336                         edesc->pset[i].opt |= TCINTEN;
 337
 338                 edesc->pset[i].src = src;
 339                 edesc->pset[i].dst = dst;
 340
 341                 edesc->pset[i].src_dst_bidx = (dst_bidx << 16) | src_bidx;
 342                 edesc->pset[i].src_dst_cidx = (dst_cidx << 16) | src_cidx;
 343
 344                 edesc->pset[i].a_b_cnt = bcnt << 16 | acnt;
 345                 edesc->pset[i].ccnt = ccnt;
 346                 edesc->pset[i].link_bcntrld = 0xffffffff;
 347
 348         }
 349
 350         return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags);
 351 }
 352
 353 static void edma_callback(unsigned ch_num, u16 ch_status, void *data)
 354 {
 355         struct edma_chan *echan = data;
 356         struct device *dev = echan->vchan.chan.device->dev;
 357         struct edma_desc *edesc;
 358         unsigned long flags;
 359
 360         /* Stop the channel */
 361         edma_stop(echan->ch_num);
 362
 363         switch (ch_status) {
 364         case DMA_COMPLETE:
 365                 dev_dbg(dev, "transfer complete on channel %d\n", ch_num);
 366
 367                 spin_lock_irqsave(&echan->vchan.lock, flags);
 368
 369                 edesc = echan->edesc;
 370                 if (edesc) {
 371                         edma_execute(echan);
 372                         vchan_cookie_complete(&edesc->vdesc);
 373                 }
 374
 375                 spin_unlock_irqrestore(&echan->vchan.lock, flags);
 376
 377                 break;
 378         case DMA_CC_ERROR:
 379                 dev_dbg(dev, "transfer error on channel %d\n", ch_num);
 380                 break;
 381         default:
 382                 break;
 383         }
 384 }
 385
 386 /* Alloc channel resources */
 387 static int edma_alloc_chan_resources(struct dma_chan *chan)
 388 {
 389         struct edma_chan *echan = to_edma_chan(chan);
 390         struct device *dev = chan->device->dev;
 391         int ret;
 392         int a_ch_num;
 393         LIST_HEAD(descs);
 394
 395         a_ch_num = edma_alloc_channel(echan->ch_num, edma_callback,
 396                                         chan, EVENTQ_DEFAULT);
 397
 398         if (a_ch_num < 0) {
 399                 ret = -ENODEV;
 400                 goto err_no_chan;
 401         }
 402
 403         if (a_ch_num != echan->ch_num) {
 404                 dev_err(dev, "failed to allocate requested channel %u:%u\n",
 405                         EDMA_CTLR(echan->ch_num),
 406                         EDMA_CHAN_SLOT(echan->ch_num));
 407                 ret = -ENODEV;
 408                 goto err_wrong_chan;
 409         }
 410
 411         echan->alloced = true;
 412         echan->slot[0] = echan->ch_num;
 413
 414         dev_info(dev, "allocated channel for %u:%u\n",
 415                  EDMA_CTLR(echan->ch_num), EDMA_CHAN_SLOT(echan->ch_num));
 416
 417         return 0;
 418
 419 err_wrong_chan:
 420         edma_free_channel(a_ch_num);
 421 err_no_chan:
 422         return ret;
 423 }
 424
 425 /* Free channel resources */
 426 static void edma_free_chan_resources(struct dma_chan *chan)
 427 {
 428         struct edma_chan *echan = to_edma_chan(chan);
 429         struct device *dev = chan->device->dev;
 430         int i;
 431
 432         /* Terminate transfers */
 433         edma_stop(echan->ch_num);
 434
 435         vchan_free_chan_resources(&echan->vchan);
 436
 437         /* Free EDMA PaRAM slots */
 438         for (i = 1; i < EDMA_MAX_SLOTS; i++) {
 439                 if (echan->slot[i] >= 0) {
 440                         edma_free_slot(echan->slot[i]);
 441                         echan->slot[i] = -1;
 442                 }
 443         }
 444
 445         /* Free EDMA channel */
 446         if (echan->alloced) {
 447                 edma_free_channel(echan->ch_num);
 448                 echan->alloced = false;
 449         }
 450
 451         dev_info(dev, "freeing channel for %u\n", echan->ch_num);
 452 }
 453
 454 /* Send pending descriptor to hardware */
 455 static void edma_issue_pending(struct dma_chan *chan)
 456 {
 457         struct edma_chan *echan = to_edma_chan(chan);
 458         unsigned long flags;
 459
 460         spin_lock_irqsave(&echan->vchan.lock, flags);
 461         if (vchan_issue_pending(&echan->vchan) && !echan->edesc)
 462                 edma_execute(echan);
 463         spin_unlock_irqrestore(&echan->vchan.lock, flags);
 464 }
 465
 466 static size_t edma_desc_size(struct edma_desc *edesc)
 467 {
 468         int i;
 469         size_t size;
 470
 471         if (edesc->absync)
 472                 for (size = i = 0; i < edesc->pset_nr; i++)
 473                         size += (edesc->pset[i].a_b_cnt & 0xffff) *
 474                                 (edesc->pset[i].a_b_cnt >> 16) *
 475                                  edesc->pset[i].ccnt;
 476         else
 477                 size = (edesc->pset[0].a_b_cnt & 0xffff) *
 478                         (edesc->pset[0].a_b_cnt >> 16) +
 479                         (edesc->pset[0].a_b_cnt & 0xffff) *
 480                         (SZ_64K - 1) * edesc->pset[0].ccnt;
 481
 482         return size;
 483 }
 484
 485 /* Check request completion status */
 486 static enum dma_status edma_tx_status(struct dma_chan *chan,
 487                                       dma_cookie_t cookie,
 488                                       struct dma_tx_state *txstate)
 489 {
 490         struct edma_chan *echan = to_edma_chan(chan);
 491         struct virt_dma_desc *vdesc;
 492         enum dma_status ret;
 493         unsigned long flags;
 494
 495         ret = dma_cookie_status(chan, cookie, txstate);
 496         if (ret == DMA_SUCCESS || !txstate)
 497                 return ret;
 498
 499         spin_lock_irqsave(&echan->vchan.lock, flags);
 500         vdesc = vchan_find_desc(&echan->vchan, cookie);
 501         if (vdesc) {
 502                 txstate->residue = edma_desc_size(to_edma_desc(&vdesc->tx));
 503         } else if (echan->edesc && echan->edesc->vdesc.tx.cookie == cookie) {
 504                 struct edma_desc *edesc = echan->edesc;
 505                 txstate->residue = edma_desc_size(edesc);
 506         } else {
 507                 txstate->residue = 0;
 508         }
 509         spin_unlock_irqrestore(&echan->vchan.lock, flags);
 510
 511         return ret;
 512 }
 513
 514 static void __init edma_chan_init(struct edma_cc *ecc,
 515                                   struct dma_device *dma,
 516                                   struct edma_chan *echans)
 517 {
 518         int i, j;
 519
 520         for (i = 0; i < EDMA_CHANS; i++) {
 521                 struct edma_chan *echan = &echans[i];
 522                 echan->ch_num = EDMA_CTLR_CHAN(ecc->ctlr, i);
 523                 echan->ecc = ecc;
 524                 echan->vchan.desc_free = edma_desc_free;
 525
 526                 vchan_init(&echan->vchan, dma);
 527
 528                 INIT_LIST_HEAD(&echan->node);
 529                 for (j = 0; j < EDMA_MAX_SLOTS; j++)
 530                         echan->slot[j] = -1;
 531         }
 532 }
 533
 534 static void edma_dma_init(struct edma_cc *ecc, struct dma_device *dma,
 535                           struct device *dev)
 536 {
 537         dma->device_prep_slave_sg = edma_prep_slave_sg;
 538         dma->device_alloc_chan_resources = edma_alloc_chan_resources;
 539         dma->device_free_chan_resources = edma_free_chan_resources;
 540         dma->device_issue_pending = edma_issue_pending;
 541         dma->device_tx_status = edma_tx_status;
 542         dma->device_control = edma_control;
 543         dma->dev = dev;
 544
 545         INIT_LIST_HEAD(&dma->channels);
 546 }
 547
 548 static int __devinit edma_probe(struct platform_device *pdev)
 549 {
 550         struct edma_cc *ecc;
 551         int ret;
 552
 553         ecc = devm_kzalloc(&pdev->dev, sizeof(*ecc), GFP_KERNEL);
 554         if (!ecc) {
 555                 dev_err(&pdev->dev, "Can't allocate controller\n");
 556                 return -ENOMEM;
 557         }
 558
 559         ecc->ctlr = pdev->id;
 560         ecc->dummy_slot = edma_alloc_slot(ecc->ctlr, EDMA_SLOT_ANY);
 561         if (ecc->dummy_slot < 0) {
 562                 dev_err(&pdev->dev, "Can't allocate PaRAM dummy slot\n");
 563                 return -EIO;
 564         }
 565
 566         dma_cap_zero(ecc->dma_slave.cap_mask);
 567         dma_cap_set(DMA_SLAVE, ecc->dma_slave.cap_mask);
 568
 569         edma_dma_init(ecc, &ecc->dma_slave, &pdev->dev);
 570
 571         edma_chan_init(ecc, &ecc->dma_slave, ecc->slave_chans);
 572
 573         ret = dma_async_device_register(&ecc->dma_slave);
 574         if (ret)
 575                 goto err_reg1;
 576
 577         platform_set_drvdata(pdev, ecc);
 578
 579         dev_info(&pdev->dev, "TI EDMA DMA engine driver\n");
 580
 581         return 0;
 582
 583 err_reg1:
 584         edma_free_slot(ecc->dummy_slot);
 585         return ret;
 586 }
 587
 588 static int __devexit edma_remove(struct platform_device *pdev)
 589 {
 590         struct device *dev = &pdev->dev;
 591         struct edma_cc *ecc = dev_get_drvdata(dev);
 592
 593         dma_async_device_unregister(&ecc->dma_slave);
 594         edma_free_slot(ecc->dummy_slot);
 595
 596         return 0;
 597 }
 598
 599 static struct platform_driver edma_driver = {
 600         .probe          = edma_probe,
 601         .remove         = __devexit_p(edma_remove),
 602         .driver = {
 603                 .name = "edma-dma-engine",
 604                 .owner = THIS_MODULE,
 605         },
 606 };
 607
 608 bool edma_filter_fn(struct dma_chan *chan, void *param)
 609 {
 610         if (chan->device->dev->driver == &edma_driver.driver) {
 611                 struct edma_chan *echan = to_edma_chan(chan);
 612                 unsigned ch_req = *(unsigned *)param;
 613                 return ch_req == echan->ch_num;
 614         }
 615         return false;
 616 }
 617 EXPORT_SYMBOL(edma_filter_fn);
 618
 619 static struct platform_device *pdev0, *pdev1;
 620
 621 static const struct platform_device_info edma_dev_info0 = {
 622         .name = "edma-dma-engine",
 623         .id = 0,
 624         .dma_mask = DMA_BIT_MASK(32),
 625 };
 626
 627 static const struct platform_device_info edma_dev_info1 = {
 628         .name = "edma-dma-engine",
 629         .id = 1,
 630         .dma_mask = DMA_BIT_MASK(32),
 631 };
 632
 633 static int edma_init(void)
 634 {
 635         int ret = platform_driver_register(&edma_driver);
 636
 637         if (ret == 0) {
 638                 pdev0 = platform_device_register_full(&edma_dev_info0);
 639                 if (IS_ERR(pdev0)) {
 640                         platform_driver_unregister(&edma_driver);
 641                         ret = PTR_ERR(pdev0);
 642                         goto out;
 643                 }
 644         }
 645
 646         if (EDMA_CTLRS == 2) {
 647                 pdev1 = platform_device_register_full(&edma_dev_info1);
 648                 if (IS_ERR(pdev1)) {
 649                         platform_driver_unregister(&edma_driver);
 650                         platform_device_unregister(pdev0);
 651                         ret = PTR_ERR(pdev1);
 652                 }
 653         }
 654
 655 out:
 656         return ret;
 657 }
 658 subsys_initcall(edma_init);
 659
 660 static void __exit edma_exit(void)
 661 {
 662         platform_device_unregister(pdev0);
 663         if (pdev1)
 664                 platform_device_unregister(pdev1);
 665         platform_driver_unregister(&edma_driver);
 666 }
 667 module_exit(edma_exit);
 668
 669 MODULE_AUTHOR("Matt Porter <[email protected]>");
 670 MODULE_DESCRIPTION("TI EDMA DMA engine driver");
 671 MODULE_LICENSE("GPL v2");