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