drivers/dma/timb_dma.c

   1 /*
   2  * timb_dma.c timberdale FPGA DMA driver
   3  * Copyright (c) 2010 Intel Corporation
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17  */
  18
  19 /* Supports:
  20  * Timberdale FPGA DMA engine
  21  */
  22
  23 #include <linux/dmaengine.h>
  24 #include <linux/dma-mapping.h>
  25 #include <linux/init.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/io.h>
  28 #include <linux/module.h>
  29 #include <linux/platform_device.h>
  30
  31 #include <linux/timb_dma.h>
  32
  33 #define DRIVER_NAME "timb-dma"
  34
  35 /* Global DMA registers */
  36 #define TIMBDMA_ACR             0x34
  37 #define TIMBDMA_32BIT_ADDR      0x01
  38
  39 #define TIMBDMA_ISR             0x080000
  40 #define TIMBDMA_IPR             0x080004
  41 #define TIMBDMA_IER             0x080008
  42
  43 /* Channel specific registers */
  44 /* RX instances base addresses are 0x00, 0x40, 0x80 ...
  45  * TX instances base addresses are 0x18, 0x58, 0x98 ...
  46  */
  47 #define TIMBDMA_INSTANCE_OFFSET         0x40
  48 #define TIMBDMA_INSTANCE_TX_OFFSET      0x18
  49
  50 /* RX registers, relative the instance base */
  51 #define TIMBDMA_OFFS_RX_DHAR    0x00
  52 #define TIMBDMA_OFFS_RX_DLAR    0x04
  53 #define TIMBDMA_OFFS_RX_LR      0x0C
  54 #define TIMBDMA_OFFS_RX_BLR     0x10
  55 #define TIMBDMA_OFFS_RX_ER      0x14
  56 #define TIMBDMA_RX_EN           0x01
  57 /* bytes per Row, video specific register
  58  * which is placed after the TX registers...
  59  */
  60 #define TIMBDMA_OFFS_RX_BPRR    0x30
  61
  62 /* TX registers, relative the instance base */
  63 #define TIMBDMA_OFFS_TX_DHAR    0x00
  64 #define TIMBDMA_OFFS_TX_DLAR    0x04
  65 #define TIMBDMA_OFFS_TX_BLR     0x0C
  66 #define TIMBDMA_OFFS_TX_LR      0x14
  67
  68
  69 #define TIMB_DMA_DESC_SIZE      8
  70
  71 struct timb_dma_desc {
  72         struct list_head                desc_node;
  73         struct dma_async_tx_descriptor  txd;
  74         u8                              *desc_list;
  75         unsigned int                    desc_list_len;
  76         bool                            interrupt;
  77 };
  78
  79 struct timb_dma_chan {
  80         struct dma_chan         chan;
  81         void __iomem            *membase;
  82         spinlock_t              lock; /* Used to protect data structures,
  83                                         especially the lists and descriptors,
  84                                         from races between the tasklet and calls
  85                                         from above */
  86         dma_cookie_t            last_completed_cookie;
  87         bool                    ongoing;
  88         struct list_head        active_list;
  89         struct list_head        queue;
  90         struct list_head        free_list;
  91         unsigned int            bytes_per_line;
  92         enum dma_data_direction direction;
  93         unsigned int            descs; /* Descriptors to allocate */
  94         unsigned int            desc_elems; /* number of elems per descriptor */
  95 };
  96
  97 struct timb_dma {
  98         struct dma_device       dma;
  99         void __iomem            *membase;
 100         struct tasklet_struct   tasklet;
 101         struct timb_dma_chan    channels[0];
 102 };
 103
 104 static struct device *chan2dev(struct dma_chan *chan)
 105 {
 106         return &chan->dev->device;
 107 }
 108 static struct device *chan2dmadev(struct dma_chan *chan)
 109 {
 110         return chan2dev(chan)->parent->parent;
 111 }
 112
 113 static struct timb_dma *tdchantotd(struct timb_dma_chan *td_chan)
 114 {
 115         int id = td_chan->chan.chan_id;
 116         return (struct timb_dma *)((u8 *)td_chan -
 117                 id * sizeof(struct timb_dma_chan) - sizeof(struct timb_dma));
 118 }
 119
 120 /* Must be called with the spinlock held */
 121 static void __td_enable_chan_irq(struct timb_dma_chan *td_chan)
 122 {
 123         int id = td_chan->chan.chan_id;
 124         struct timb_dma *td = tdchantotd(td_chan);
 125         u32 ier;
 126
 127         /* enable interrupt for this channel */
 128         ier = ioread32(td->membase + TIMBDMA_IER);
 129         ier |= 1 << id;
 130         dev_dbg(chan2dev(&td_chan->chan), "Enabling irq: %d, IER: 0x%x\n", id,
 131                 ier);
 132         iowrite32(ier, td->membase + TIMBDMA_IER);
 133 }
 134
 135 /* Should be called with the spinlock held */
 136 static bool __td_dma_done_ack(struct timb_dma_chan *td_chan)
 137 {
 138         int id = td_chan->chan.chan_id;
 139         struct timb_dma *td = (struct timb_dma *)((u8 *)td_chan -
 140                 id * sizeof(struct timb_dma_chan) - sizeof(struct timb_dma));
 141         u32 isr;
 142         bool done = false;
 143
 144         dev_dbg(chan2dev(&td_chan->chan), "Checking irq: %d, td: %p\n", id, td);
 145
 146         isr = ioread32(td->membase + TIMBDMA_ISR) & (1 << id);
 147         if (isr) {
 148                 iowrite32(isr, td->membase + TIMBDMA_ISR);
 149                 done = true;
 150         }
 151
 152         return done;
 153 }
 154
 155 static void __td_unmap_desc(struct timb_dma_chan *td_chan, const u8 *dma_desc,
 156         bool single)
 157 {
 158         dma_addr_t addr;
 159         int len;
 160
 161         addr = (dma_desc[7] << 24) | (dma_desc[6] << 16) | (dma_desc[5] << 8) |
 162                 dma_desc[4];
 163
 164         len = (dma_desc[3] << 8) | dma_desc[2];
 165
 166         if (single)
 167                 dma_unmap_single(chan2dev(&td_chan->chan), addr, len,
 168                         td_chan->direction);
 169         else
 170                 dma_unmap_page(chan2dev(&td_chan->chan), addr, len,
 171                         td_chan->direction);
 172 }
 173
 174 static void __td_unmap_descs(struct timb_dma_desc *td_desc, bool single)
 175 {
 176         struct timb_dma_chan *td_chan = container_of(td_desc->txd.chan,
 177                 struct timb_dma_chan, chan);
 178         u8 *descs;
 179
 180         for (descs = td_desc->desc_list; ; descs += TIMB_DMA_DESC_SIZE) {
 181                 __td_unmap_desc(td_chan, descs, single);
 182                 if (descs[0] & 0x02)
 183                         break;
 184         }
 185 }
 186
 187 static int td_fill_desc(struct timb_dma_chan *td_chan, u8 *dma_desc,
 188         struct scatterlist *sg, bool last)
 189 {
 190         if (sg_dma_len(sg) > USHORT_MAX) {
 191                 dev_err(chan2dev(&td_chan->chan), "Too big sg element\n");
 192                 return -EINVAL;
 193         }
 194
 195         /* length must be word aligned */
 196         if (sg_dma_len(sg) % sizeof(u32)) {
 197                 dev_err(chan2dev(&td_chan->chan), "Incorrect length: %d\n",
 198                         sg_dma_len(sg));
 199                 return -EINVAL;
 200         }
 201
 202         dev_dbg(chan2dev(&td_chan->chan), "desc: %p, addr: %p\n",
 203                 dma_desc, (void *)sg_dma_address(sg));
 204
 205         dma_desc[7] = (sg_dma_address(sg) >> 24) & 0xff;
 206         dma_desc[6] = (sg_dma_address(sg) >> 16) & 0xff;
 207         dma_desc[5] = (sg_dma_address(sg) >> 8) & 0xff;
 208         dma_desc[4] = (sg_dma_address(sg) >> 0) & 0xff;
 209
 210         dma_desc[3] = (sg_dma_len(sg) >> 8) & 0xff;
 211         dma_desc[2] = (sg_dma_len(sg) >> 0) & 0xff;
 212
 213         dma_desc[1] = 0x00;
 214         dma_desc[0] = 0x21 | (last ? 0x02 : 0); /* tran, valid */
 215
 216         return 0;
 217 }
 218
 219 /* Must be called with the spinlock held */
 220 static void __td_start_dma(struct timb_dma_chan *td_chan)
 221 {
 222         struct timb_dma_desc *td_desc;
 223
 224         if (td_chan->ongoing) {
 225                 dev_err(chan2dev(&td_chan->chan),
 226                         "Transfer already ongoing\n");
 227                 return;
 228         }
 229
 230         td_desc = list_entry(td_chan->active_list.next, struct timb_dma_desc,
 231                 desc_node);
 232
 233         dev_dbg(chan2dev(&td_chan->chan),
 234                 "td_chan: %p, chan: %d, membase: %p\n",
 235                 td_chan, td_chan->chan.chan_id, td_chan->membase);
 236
 237         if (td_chan->direction == DMA_FROM_DEVICE) {
 238
 239                 /* descriptor address */
 240                 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_RX_DHAR);
 241                 iowrite32(td_desc->txd.phys, td_chan->membase +
 242                         TIMBDMA_OFFS_RX_DLAR);
 243                 /* Bytes per line */
 244                 iowrite32(td_chan->bytes_per_line, td_chan->membase +
 245                         TIMBDMA_OFFS_RX_BPRR);
 246                 /* enable RX */
 247                 iowrite32(TIMBDMA_RX_EN, td_chan->membase + TIMBDMA_OFFS_RX_ER);
 248         } else {
 249                 /* address high */
 250                 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_TX_DHAR);
 251                 iowrite32(td_desc->txd.phys, td_chan->membase +
 252                         TIMBDMA_OFFS_TX_DLAR);
 253         }
 254
 255         td_chan->ongoing = true;
 256
 257         if (td_desc->interrupt)
 258                 __td_enable_chan_irq(td_chan);
 259 }
 260
 261 static void __td_finish(struct timb_dma_chan *td_chan)
 262 {
 263         dma_async_tx_callback           callback;
 264         void                            *param;
 265         struct dma_async_tx_descriptor  *txd;
 266         struct timb_dma_desc            *td_desc;
 267
 268         /* can happen if the descriptor is canceled */
 269         if (list_empty(&td_chan->active_list))
 270                 return;
 271
 272         td_desc = list_entry(td_chan->active_list.next, struct timb_dma_desc,
 273                 desc_node);
 274         txd = &td_desc->txd;
 275
 276         dev_dbg(chan2dev(&td_chan->chan), "descriptor %u complete\n",
 277                 txd->cookie);
 278
 279         /* make sure to stop the transfer */
 280         if (td_chan->direction == DMA_FROM_DEVICE)
 281                 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_RX_ER);
 282 /* Currently no support for stopping DMA transfers
 283         else
 284                 iowrite32(0, td_chan->membase + TIMBDMA_OFFS_TX_DLAR);
 285 */
 286         td_chan->last_completed_cookie = txd->cookie;
 287         td_chan->ongoing = false;
 288
 289         callback = txd->callback;
 290         param = txd->callback_param;
 291
 292         list_move(&td_desc->desc_node, &td_chan->free_list);
 293
 294         if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP))
 295                 __td_unmap_descs(td_desc,
 296                         txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE);
 297
 298         /*
 299          * The API requires that no submissions are done from a
 300          * callback, so we don't need to drop the lock here
 301          */
 302         if (callback)
 303                 callback(param);
 304 }
 305
 306 static u32 __td_ier_mask(struct timb_dma *td)
 307 {
 308         int i;
 309         u32 ret = 0;
 310
 311         for (i = 0; i < td->dma.chancnt; i++) {
 312                 struct timb_dma_chan *td_chan = td->channels + i;
 313                 if (td_chan->ongoing) {
 314                         struct timb_dma_desc *td_desc =
 315                                 list_entry(td_chan->active_list.next,
 316                                 struct timb_dma_desc, desc_node);
 317                         if (td_desc->interrupt)
 318                                 ret |= 1 << i;
 319                 }
 320         }
 321
 322         return ret;
 323 }
 324
 325 static void __td_start_next(struct timb_dma_chan *td_chan)
 326 {
 327         struct timb_dma_desc *td_desc;
 328
 329         BUG_ON(list_empty(&td_chan->queue));
 330         BUG_ON(td_chan->ongoing);
 331
 332         td_desc = list_entry(td_chan->queue.next, struct timb_dma_desc,
 333                 desc_node);
 334
 335         dev_dbg(chan2dev(&td_chan->chan), "%s: started %u\n",
 336                 __func__, td_desc->txd.cookie);
 337
 338         list_move(&td_desc->desc_node, &td_chan->active_list);
 339         __td_start_dma(td_chan);
 340 }
 341
 342 static dma_cookie_t td_tx_submit(struct dma_async_tx_descriptor *txd)
 343 {
 344         struct timb_dma_desc *td_desc = container_of(txd, struct timb_dma_desc,
 345                 txd);
 346         struct timb_dma_chan *td_chan = container_of(txd->chan,
 347                 struct timb_dma_chan, chan);
 348         dma_cookie_t cookie;
 349
 350         spin_lock_bh(&td_chan->lock);
 351
 352         cookie = txd->chan->cookie;
 353         if (++cookie < 0)
 354                 cookie = 1;
 355         txd->chan->cookie = cookie;
 356         txd->cookie = cookie;
 357
 358         if (list_empty(&td_chan->active_list)) {
 359                 dev_dbg(chan2dev(txd->chan), "%s: started %u\n", __func__,
 360                         txd->cookie);
 361                 list_add_tail(&td_desc->desc_node, &td_chan->active_list);
 362                 __td_start_dma(td_chan);
 363         } else {
 364                 dev_dbg(chan2dev(txd->chan), "tx_submit: queued %u\n",
 365                         txd->cookie);
 366
 367                 list_add_tail(&td_desc->desc_node, &td_chan->queue);
 368         }
 369
 370         spin_unlock_bh(&td_chan->lock);
 371
 372         return cookie;
 373 }
 374
 375 static struct timb_dma_desc *td_alloc_init_desc(struct timb_dma_chan *td_chan)
 376 {
 377         struct dma_chan *chan = &td_chan->chan;
 378         struct timb_dma_desc *td_desc;
 379         int err;
 380
 381         td_desc = kzalloc(sizeof(struct timb_dma_desc), GFP_KERNEL);
 382         if (!td_desc) {
 383                 dev_err(chan2dev(chan), "Failed to alloc descriptor\n");
 384                 goto err;
 385         }
 386
 387         td_desc->desc_list_len = td_chan->desc_elems * TIMB_DMA_DESC_SIZE;
 388
 389         td_desc->desc_list = kzalloc(td_desc->desc_list_len, GFP_KERNEL);
 390         if (!td_desc->desc_list) {
 391                 dev_err(chan2dev(chan), "Failed to alloc descriptor\n");
 392                 goto err;
 393         }
 394
 395         dma_async_tx_descriptor_init(&td_desc->txd, chan);
 396         td_desc->txd.tx_submit = td_tx_submit;
 397         td_desc->txd.flags = DMA_CTRL_ACK;
 398
 399         td_desc->txd.phys = dma_map_single(chan2dmadev(chan),
 400                 td_desc->desc_list, td_desc->desc_list_len, DMA_TO_DEVICE);
 401
 402         err = dma_mapping_error(chan2dmadev(chan), td_desc->txd.phys);
 403         if (err) {
 404                 dev_err(chan2dev(chan), "DMA mapping error: %d\n", err);
 405                 goto err;
 406         }
 407
 408         return td_desc;
 409 err:
 410         kfree(td_desc->desc_list);
 411         kfree(td_desc);
 412
 413         return NULL;
 414
 415 }
 416
 417 static void td_free_desc(struct timb_dma_desc *td_desc)
 418 {
 419         dev_dbg(chan2dev(td_desc->txd.chan), "Freeing desc: %p\n", td_desc);
 420         dma_unmap_single(chan2dmadev(td_desc->txd.chan), td_desc->txd.phys,
 421                 td_desc->desc_list_len, DMA_TO_DEVICE);
 422
 423         kfree(td_desc->desc_list);
 424         kfree(td_desc);
 425 }
 426
 427 static void td_desc_put(struct timb_dma_chan *td_chan,
 428         struct timb_dma_desc *td_desc)
 429 {
 430         dev_dbg(chan2dev(&td_chan->chan), "Putting desc: %p\n", td_desc);
 431
 432         spin_lock_bh(&td_chan->lock);
 433         list_add(&td_desc->desc_node, &td_chan->free_list);
 434         spin_unlock_bh(&td_chan->lock);
 435 }
 436
 437 static struct timb_dma_desc *td_desc_get(struct timb_dma_chan *td_chan)
 438 {
 439         struct timb_dma_desc *td_desc, *_td_desc;
 440         struct timb_dma_desc *ret = NULL;
 441
 442         spin_lock_bh(&td_chan->lock);
 443         list_for_each_entry_safe(td_desc, _td_desc, &td_chan->free_list,
 444                 desc_node) {
 445                 if (async_tx_test_ack(&td_desc->txd)) {
 446                         list_del(&td_desc->desc_node);
 447                         ret = td_desc;
 448                         break;
 449                 }
 450                 dev_dbg(chan2dev(&td_chan->chan), "desc %p not ACKed\n",
 451                         td_desc);
 452         }
 453         spin_unlock_bh(&td_chan->lock);
 454
 455         return ret;
 456 }
 457
 458 static int td_alloc_chan_resources(struct dma_chan *chan)
 459 {
 460         struct timb_dma_chan *td_chan =
 461                 container_of(chan, struct timb_dma_chan, chan);
 462         int i;
 463
 464         dev_dbg(chan2dev(chan), "%s: entry\n", __func__);
 465
 466         BUG_ON(!list_empty(&td_chan->free_list));
 467         for (i = 0; i < td_chan->descs; i++) {
 468                 struct timb_dma_desc *td_desc = td_alloc_init_desc(td_chan);
 469                 if (!td_desc) {
 470                         if (i)
 471                                 break;
 472                         else {
 473                                 dev_err(chan2dev(chan),
 474                                         "Couldnt allocate any descriptors\n");
 475                                 return -ENOMEM;
 476                         }
 477                 }
 478
 479                 td_desc_put(td_chan, td_desc);
 480         }
 481
 482         spin_lock_bh(&td_chan->lock);
 483         td_chan->last_completed_cookie = 1;
 484         chan->cookie = 1;
 485         spin_unlock_bh(&td_chan->lock);
 486
 487         return 0;
 488 }
 489
 490 static void td_free_chan_resources(struct dma_chan *chan)
 491 {
 492         struct timb_dma_chan *td_chan =
 493                 container_of(chan, struct timb_dma_chan, chan);
 494         struct timb_dma_desc *td_desc, *_td_desc;
 495         LIST_HEAD(list);
 496
 497         dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
 498
 499         /* check that all descriptors are free */
 500         BUG_ON(!list_empty(&td_chan->active_list));
 501         BUG_ON(!list_empty(&td_chan->queue));
 502
 503         spin_lock_bh(&td_chan->lock);
 504         list_splice_init(&td_chan->free_list, &list);
 505         spin_unlock_bh(&td_chan->lock);
 506
 507         list_for_each_entry_safe(td_desc, _td_desc, &list, desc_node) {
 508                 dev_dbg(chan2dev(chan), "%s: Freeing desc: %p\n", __func__,
 509                         td_desc);
 510                 td_free_desc(td_desc);
 511         }
 512 }
 513
 514 static enum dma_status td_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
 515                                     struct dma_tx_state *txstate)
 516 {
 517         struct timb_dma_chan *td_chan =
 518                 container_of(chan, struct timb_dma_chan, chan);
 519         dma_cookie_t            last_used;
 520         dma_cookie_t            last_complete;
 521         int                     ret;
 522
 523         dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
 524
 525         last_complete = td_chan->last_completed_cookie;
 526         last_used = chan->cookie;
 527
 528         ret = dma_async_is_complete(cookie, last_complete, last_used);
 529
 530         if (txstate) {
 531                 txstate->last = last_complete;
 532                 txstate->used = last_used;
 533                 txstate->residue = 0;
 534         }
 535
 536         dev_dbg(chan2dev(chan),
 537                 "%s: exit, ret: %d, last_complete: %d, last_used: %d\n",
 538                 __func__, ret, last_complete, last_used);
 539
 540         return ret;
 541 }
 542
 543 static void td_issue_pending(struct dma_chan *chan)
 544 {
 545         struct timb_dma_chan *td_chan =
 546                 container_of(chan, struct timb_dma_chan, chan);
 547
 548         dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
 549         spin_lock_bh(&td_chan->lock);
 550
 551         if (!list_empty(&td_chan->active_list))
 552                 /* transfer ongoing */
 553                 if (__td_dma_done_ack(td_chan))
 554                         __td_finish(td_chan);
 555
 556         if (list_empty(&td_chan->active_list) && !list_empty(&td_chan->queue))
 557                 __td_start_next(td_chan);
 558
 559         spin_unlock_bh(&td_chan->lock);
 560 }
 561
 562 static struct dma_async_tx_descriptor *td_prep_slave_sg(struct dma_chan *chan,
 563         struct scatterlist *sgl, unsigned int sg_len,
 564         enum dma_data_direction direction, unsigned long flags)
 565 {
 566         struct timb_dma_chan *td_chan =
 567                 container_of(chan, struct timb_dma_chan, chan);
 568         struct timb_dma_desc *td_desc;
 569         struct scatterlist *sg;
 570         unsigned int i;
 571         unsigned int desc_usage = 0;
 572
 573         if (!sgl || !sg_len) {
 574                 dev_err(chan2dev(chan), "%s: No SG list\n", __func__);
 575                 return NULL;
 576         }
 577
 578         /* even channels are for RX, odd for TX */
 579         if (td_chan->direction != direction) {
 580                 dev_err(chan2dev(chan),
 581                         "Requesting channel in wrong direction\n");
 582                 return NULL;
 583         }
 584
 585         td_desc = td_desc_get(td_chan);
 586         if (!td_desc) {
 587                 dev_err(chan2dev(chan), "Not enough descriptors available\n");
 588                 return NULL;
 589         }
 590
 591         td_desc->interrupt = (flags & DMA_PREP_INTERRUPT) != 0;
 592
 593         for_each_sg(sgl, sg, sg_len, i) {
 594                 int err;
 595                 if (desc_usage > td_desc->desc_list_len) {
 596                         dev_err(chan2dev(chan), "No descriptor space\n");
 597                         return NULL;
 598                 }
 599
 600                 err = td_fill_desc(td_chan, td_desc->desc_list + desc_usage, sg,
 601                         i == (sg_len - 1));
 602                 if (err) {
 603                         dev_err(chan2dev(chan), "Failed to update desc: %d\n",
 604                                 err);
 605                         td_desc_put(td_chan, td_desc);
 606                         return NULL;
 607                 }
 608                 desc_usage += TIMB_DMA_DESC_SIZE;
 609         }
 610
 611         dma_sync_single_for_device(chan2dmadev(chan), td_desc->txd.phys,
 612                 td_desc->desc_list_len, DMA_TO_DEVICE);
 613
 614         return &td_desc->txd;
 615 }
 616
 617 static int td_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd)
 618 {
 619         struct timb_dma_chan *td_chan =
 620                 container_of(chan, struct timb_dma_chan, chan);
 621         struct timb_dma_desc *td_desc, *_td_desc;
 622
 623         dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
 624
 625         if (cmd != DMA_TERMINATE_ALL)
 626                 return -ENXIO;
 627
 628         /* first the easy part, put the queue into the free list */
 629         spin_lock_bh(&td_chan->lock);
 630         list_for_each_entry_safe(td_desc, _td_desc, &td_chan->queue,
 631                 desc_node)
 632                 list_move(&td_desc->desc_node, &td_chan->free_list);
 633
 634         /* now tear down the runnning */
 635         __td_finish(td_chan);
 636         spin_unlock_bh(&td_chan->lock);
 637
 638         return 0;
 639 }
 640
 641 static void td_tasklet(unsigned long data)
 642 {
 643         struct timb_dma *td = (struct timb_dma *)data;
 644         u32 isr;
 645         u32 ipr;
 646         u32 ier;
 647         int i;
 648
 649         isr = ioread32(td->membase + TIMBDMA_ISR);
 650         ipr = isr & __td_ier_mask(td);
 651
 652         /* ack the interrupts */
 653         iowrite32(ipr, td->membase + TIMBDMA_ISR);
 654
 655         for (i = 0; i < td->dma.chancnt; i++)
 656                 if (ipr & (1 << i)) {
 657                         struct timb_dma_chan *td_chan = td->channels + i;
 658                         spin_lock(&td_chan->lock);
 659                         __td_finish(td_chan);
 660                         if (!list_empty(&td_chan->queue))
 661                                 __td_start_next(td_chan);
 662                         spin_unlock(&td_chan->lock);
 663                 }
 664
 665         ier = __td_ier_mask(td);
 666         iowrite32(ier, td->membase + TIMBDMA_IER);
 667 }
 668
 669
 670 static irqreturn_t td_irq(int irq, void *devid)
 671 {
 672         struct timb_dma *td = devid;
 673         u32 ipr = ioread32(td->membase + TIMBDMA_IPR);
 674
 675         if (ipr) {
 676                 /* disable interrupts, will be re-enabled in tasklet */
 677                 iowrite32(0, td->membase + TIMBDMA_IER);
 678
 679                 tasklet_schedule(&td->tasklet);
 680
 681                 return IRQ_HANDLED;
 682         } else
 683                 return IRQ_NONE;
 684 }
 685
 686
 687 static int __devinit td_probe(struct platform_device *pdev)
 688 {
 689         struct timb_dma_platform_data *pdata = pdev->dev.platform_data;
 690         struct timb_dma *td;
 691         struct resource *iomem;
 692         int irq;
 693         int err;
 694         int i;
 695
 696         if (!pdata) {
 697                 dev_err(&pdev->dev, "No platform data\n");
 698                 return -EINVAL;
 699         }
 700
 701         iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 702         if (!iomem)
 703                 return -EINVAL;
 704
 705         irq = platform_get_irq(pdev, 0);
 706         if (irq < 0)
 707                 return irq;
 708
 709         if (!request_mem_region(iomem->start, resource_size(iomem),
 710                 DRIVER_NAME))
 711                 return -EBUSY;
 712
 713         td  = kzalloc(sizeof(struct timb_dma) +
 714                 sizeof(struct timb_dma_chan) * pdata->nr_channels, GFP_KERNEL);
 715         if (!td) {
 716                 err = -ENOMEM;
 717                 goto err_release_region;
 718         }
 719
 720         dev_dbg(&pdev->dev, "Allocated TD: %p\n", td);
 721
 722         td->membase = ioremap(iomem->start, resource_size(iomem));
 723         if (!td->membase) {
 724                 dev_err(&pdev->dev, "Failed to remap I/O memory\n");
 725                 err = -ENOMEM;
 726                 goto err_free_mem;
 727         }
 728
 729         /* 32bit addressing */
 730         iowrite32(TIMBDMA_32BIT_ADDR, td->membase + TIMBDMA_ACR);
 731
 732         /* disable and clear any interrupts */
 733         iowrite32(0x0, td->membase + TIMBDMA_IER);
 734         iowrite32(0xFFFFFFFF, td->membase + TIMBDMA_ISR);
 735
 736         tasklet_init(&td->tasklet, td_tasklet, (unsigned long)td);
 737
 738         err = request_irq(irq, td_irq, IRQF_SHARED, DRIVER_NAME, td);
 739         if (err) {
 740                 dev_err(&pdev->dev, "Failed to request IRQ\n");
 741                 goto err_tasklet_kill;
 742         }
 743
 744         td->dma.device_alloc_chan_resources     = td_alloc_chan_resources;
 745         td->dma.device_free_chan_resources      = td_free_chan_resources;
 746         td->dma.device_tx_status                = td_tx_status;
 747         td->dma.device_issue_pending            = td_issue_pending;
 748
 749         dma_cap_set(DMA_SLAVE, td->dma.cap_mask);
 750         dma_cap_set(DMA_PRIVATE, td->dma.cap_mask);
 751         td->dma.device_prep_slave_sg = td_prep_slave_sg;
 752         td->dma.device_control = td_control;
 753
 754         td->dma.dev = &pdev->dev;
 755
 756         INIT_LIST_HEAD(&td->dma.channels);
 757
 758         for (i = 0; i < pdata->nr_channels; i++, td->dma.chancnt++) {
 759                 struct timb_dma_chan *td_chan = &td->channels[i];
 760                 struct timb_dma_platform_data_channel *pchan =
 761                         pdata->channels + i;
 762
 763                 /* even channels are RX, odd are TX */
 764                 if (((i % 2) && pchan->rx) || (!(i % 2) && !pchan->rx)) {
 765                         dev_err(&pdev->dev, "Wrong channel configuration\n");
 766                         err = -EINVAL;
 767                         goto err_tasklet_kill;
 768                 }
 769
 770                 td_chan->chan.device = &td->dma;
 771                 td_chan->chan.cookie = 1;
 772                 td_chan->chan.chan_id = i;
 773                 spin_lock_init(&td_chan->lock);
 774                 INIT_LIST_HEAD(&td_chan->active_list);
 775                 INIT_LIST_HEAD(&td_chan->queue);
 776                 INIT_LIST_HEAD(&td_chan->free_list);
 777
 778                 td_chan->descs = pchan->descriptors;
 779                 td_chan->desc_elems = pchan->descriptor_elements;
 780                 td_chan->bytes_per_line = pchan->bytes_per_line;
 781                 td_chan->direction = pchan->rx ? DMA_FROM_DEVICE :
 782                         DMA_TO_DEVICE;
 783
 784                 td_chan->membase = td->membase +
 785                         (i / 2) * TIMBDMA_INSTANCE_OFFSET +
 786                         (pchan->rx ? 0 : TIMBDMA_INSTANCE_TX_OFFSET);
 787
 788                 dev_dbg(&pdev->dev, "Chan: %d, membase: %p\n",
 789                         i, td_chan->membase);
 790
 791                 list_add_tail(&td_chan->chan.device_node, &td->dma.channels);
 792         }
 793
 794         err = dma_async_device_register(&td->dma);
 795         if (err) {
 796                 dev_err(&pdev->dev, "Failed to register async device\n");
 797                 goto err_free_irq;
 798         }
 799
 800         platform_set_drvdata(pdev, td);
 801
 802         dev_dbg(&pdev->dev, "Probe result: %d\n", err);
 803         return err;
 804
 805 err_free_irq:
 806         free_irq(irq, td);
 807 err_tasklet_kill:
 808         tasklet_kill(&td->tasklet);
 809         iounmap(td->membase);
 810 err_free_mem:
 811         kfree(td);
 812 err_release_region:
 813         release_mem_region(iomem->start, resource_size(iomem));
 814
 815         return err;
 816
 817 }
 818
 819 static int __devexit td_remove(struct platform_device *pdev)
 820 {
 821         struct timb_dma *td = platform_get_drvdata(pdev);
 822         struct resource *iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 823         int irq = platform_get_irq(pdev, 0);
 824
 825         dma_async_device_unregister(&td->dma);
 826         free_irq(irq, td);
 827         tasklet_kill(&td->tasklet);
 828         iounmap(td->membase);
 829         kfree(td);
 830         release_mem_region(iomem->start, resource_size(iomem));
 831
 832         platform_set_drvdata(pdev, NULL);
 833
 834         dev_dbg(&pdev->dev, "Removed...\n");
 835         return 0;
 836 }
 837
 838 static struct platform_driver td_driver = {
 839         .driver = {
 840                 .name   = DRIVER_NAME,
 841                 .owner  = THIS_MODULE,
 842         },
 843         .probe  = td_probe,
 844         .remove = __exit_p(td_remove),
 845 };
 846
 847 static int __init td_init(void)
 848 {
 849         return platform_driver_register(&td_driver);
 850 }
 851 module_init(td_init);
 852
 853 static void __exit td_exit(void)
 854 {
 855         platform_driver_unregister(&td_driver);
 856 }
 857 module_exit(td_exit);
 858
 859 MODULE_LICENSE("GPL v2");
 860 MODULE_DESCRIPTION("Timberdale DMA controller driver");
 861 MODULE_AUTHOR("Pelagicore AB <info@pelagicore.com>");
 862 MODULE_ALIAS("platform:"DRIVER_NAME);