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/delay.h>
   9 #include <linux/dmaengine.h>
  10 #include <linux/dma-mapping.h>
  11 #include <linux/err.h>
  12 #include <linux/init.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/list.h>
  15 #include <linux/module.h>
  16 #include <linux/omap-dma.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/slab.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/of_dma.h>
  21 #include <linux/of_device.h>
  22
  23 #include "virt-dma.h"
  24
  25 struct omap_dmadev {
  26         struct dma_device ddev;
  27         spinlock_t lock;
  28         struct tasklet_struct task;
  29         struct list_head pending;
  30         void __iomem *base;
  31         const struct omap_dma_reg *reg_map;
  32         struct omap_system_dma_plat_info *plat;
  33         bool legacy;
  34         spinlock_t irq_lock;
  35         uint32_t irq_enable_mask;
  36         struct omap_chan *lch_map[32];
  37 };
  38
  39 struct omap_chan {
  40         struct virt_dma_chan vc;
  41         struct list_head node;
  42         void __iomem *channel_base;
  43         const struct omap_dma_reg *reg_map;
  44         uint32_t ccr;
  45
  46         struct dma_slave_config cfg;
  47         unsigned dma_sig;
  48         bool cyclic;
  49         bool paused;
  50
  51         int dma_ch;
  52         struct omap_desc *desc;
  53         unsigned sgidx;
  54 };
  55
  56 struct omap_sg {
  57         dma_addr_t addr;
  58         uint32_t en;            /* number of elements (24-bit) */
  59         uint32_t fn;            /* number of frames (16-bit) */
  60 };
  61
  62 struct omap_desc {
  63         struct virt_dma_desc vd;
  64         enum dma_transfer_direction dir;
  65         dma_addr_t dev_addr;
  66
  67         int16_t fi;             /* for OMAP_DMA_SYNC_PACKET */
  68         uint8_t es;             /* CSDP_DATA_TYPE_xxx */
  69         uint32_t ccr;           /* CCR value */
  70         uint16_t clnk_ctrl;     /* CLNK_CTRL value */
  71         uint16_t cicr;          /* CICR value */
  72         uint32_t csdp;          /* CSDP value */
  73
  74         unsigned sglen;
  75         struct omap_sg sg[0];
  76 };
  77
  78 enum {
  79         CCR_FS                  = BIT(5),
  80         CCR_READ_PRIORITY       = BIT(6),
  81         CCR_ENABLE              = BIT(7),
  82         CCR_AUTO_INIT           = BIT(8),       /* OMAP1 only */
  83         CCR_REPEAT              = BIT(9),       /* OMAP1 only */
  84         CCR_OMAP31_DISABLE      = BIT(10),      /* OMAP1 only */
  85         CCR_SUSPEND_SENSITIVE   = BIT(8),       /* OMAP2+ only */
  86         CCR_RD_ACTIVE           = BIT(9),       /* OMAP2+ only */
  87         CCR_WR_ACTIVE           = BIT(10),      /* OMAP2+ only */
  88         CCR_SRC_AMODE_CONSTANT  = 0 << 12,
  89         CCR_SRC_AMODE_POSTINC   = 1 << 12,
  90         CCR_SRC_AMODE_SGLIDX    = 2 << 12,
  91         CCR_SRC_AMODE_DBLIDX    = 3 << 12,
  92         CCR_DST_AMODE_CONSTANT  = 0 << 14,
  93         CCR_DST_AMODE_POSTINC   = 1 << 14,
  94         CCR_DST_AMODE_SGLIDX    = 2 << 14,
  95         CCR_DST_AMODE_DBLIDX    = 3 << 14,
  96         CCR_CONSTANT_FILL       = BIT(16),
  97         CCR_TRANSPARENT_COPY    = BIT(17),
  98         CCR_BS                  = BIT(18),
  99         CCR_SUPERVISOR          = BIT(22),
 100         CCR_PREFETCH            = BIT(23),
 101         CCR_TRIGGER_SRC         = BIT(24),
 102         CCR_BUFFERING_DISABLE   = BIT(25),
 103         CCR_WRITE_PRIORITY      = BIT(26),
 104         CCR_SYNC_ELEMENT        = 0,
 105         CCR_SYNC_FRAME          = CCR_FS,
 106         CCR_SYNC_BLOCK          = CCR_BS,
 107         CCR_SYNC_PACKET         = CCR_BS | CCR_FS,
 108
 109         CSDP_DATA_TYPE_8        = 0,
 110         CSDP_DATA_TYPE_16       = 1,
 111         CSDP_DATA_TYPE_32       = 2,
 112         CSDP_SRC_PORT_EMIFF     = 0 << 2, /* OMAP1 only */
 113         CSDP_SRC_PORT_EMIFS     = 1 << 2, /* OMAP1 only */
 114         CSDP_SRC_PORT_OCP_T1    = 2 << 2, /* OMAP1 only */
 115         CSDP_SRC_PORT_TIPB      = 3 << 2, /* OMAP1 only */
 116         CSDP_SRC_PORT_OCP_T2    = 4 << 2, /* OMAP1 only */
 117         CSDP_SRC_PORT_MPUI      = 5 << 2, /* OMAP1 only */
 118         CSDP_SRC_PACKED         = BIT(6),
 119         CSDP_SRC_BURST_1        = 0 << 7,
 120         CSDP_SRC_BURST_16       = 1 << 7,
 121         CSDP_SRC_BURST_32       = 2 << 7,
 122         CSDP_SRC_BURST_64       = 3 << 7,
 123         CSDP_DST_PORT_EMIFF     = 0 << 9, /* OMAP1 only */
 124         CSDP_DST_PORT_EMIFS     = 1 << 9, /* OMAP1 only */
 125         CSDP_DST_PORT_OCP_T1    = 2 << 9, /* OMAP1 only */
 126         CSDP_DST_PORT_TIPB      = 3 << 9, /* OMAP1 only */
 127         CSDP_DST_PORT_OCP_T2    = 4 << 9, /* OMAP1 only */
 128         CSDP_DST_PORT_MPUI      = 5 << 9, /* OMAP1 only */
 129         CSDP_DST_PACKED         = BIT(13),
 130         CSDP_DST_BURST_1        = 0 << 14,
 131         CSDP_DST_BURST_16       = 1 << 14,
 132         CSDP_DST_BURST_32       = 2 << 14,
 133         CSDP_DST_BURST_64       = 3 << 14,
 134
 135         CICR_TOUT_IE            = BIT(0),       /* OMAP1 only */
 136         CICR_DROP_IE            = BIT(1),
 137         CICR_HALF_IE            = BIT(2),
 138         CICR_FRAME_IE           = BIT(3),
 139         CICR_LAST_IE            = BIT(4),
 140         CICR_BLOCK_IE           = BIT(5),
 141         CICR_PKT_IE             = BIT(7),       /* OMAP2+ only */
 142         CICR_TRANS_ERR_IE       = BIT(8),       /* OMAP2+ only */
 143         CICR_SUPERVISOR_ERR_IE  = BIT(10),      /* OMAP2+ only */
 144         CICR_MISALIGNED_ERR_IE  = BIT(11),      /* OMAP2+ only */
 145         CICR_DRAIN_IE           = BIT(12),      /* OMAP2+ only */
 146         CICR_SUPER_BLOCK_IE     = BIT(14),      /* OMAP2+ only */
 147
 148         CLNK_CTRL_ENABLE_LNK    = BIT(15),
 149 };
 150
 151 static const unsigned es_bytes[] = {
 152         [CSDP_DATA_TYPE_8] = 1,
 153         [CSDP_DATA_TYPE_16] = 2,
 154         [CSDP_DATA_TYPE_32] = 4,
 155 };
 156
 157 static struct of_dma_filter_info omap_dma_info = {
 158         .filter_fn = omap_dma_filter_fn,
 159 };
 160
 161 static inline struct omap_dmadev *to_omap_dma_dev(struct dma_device *d)
 162 {
 163         return container_of(d, struct omap_dmadev, ddev);
 164 }
 165
 166 static inline struct omap_chan *to_omap_dma_chan(struct dma_chan *c)
 167 {
 168         return container_of(c, struct omap_chan, vc.chan);
 169 }
 170
 171 static inline struct omap_desc *to_omap_dma_desc(struct dma_async_tx_descriptor *t)
 172 {
 173         return container_of(t, struct omap_desc, vd.tx);
 174 }
 175
 176 static void omap_dma_desc_free(struct virt_dma_desc *vd)
 177 {
 178         kfree(container_of(vd, struct omap_desc, vd));
 179 }
 180
 181 static void omap_dma_write(uint32_t val, unsigned type, void __iomem *addr)
 182 {
 183         switch (type) {
 184         case OMAP_DMA_REG_16BIT:
 185                 writew_relaxed(val, addr);
 186                 break;
 187         case OMAP_DMA_REG_2X16BIT:
 188                 writew_relaxed(val, addr);
 189                 writew_relaxed(val >> 16, addr + 2);
 190                 break;
 191         case OMAP_DMA_REG_32BIT:
 192                 writel_relaxed(val, addr);
 193                 break;
 194         default:
 195                 WARN_ON(1);
 196         }
 197 }
 198
 199 static unsigned omap_dma_read(unsigned type, void __iomem *addr)
 200 {
 201         unsigned val;
 202
 203         switch (type) {
 204         case OMAP_DMA_REG_16BIT:
 205                 val = readw_relaxed(addr);
 206                 break;
 207         case OMAP_DMA_REG_2X16BIT:
 208                 val = readw_relaxed(addr);
 209                 val |= readw_relaxed(addr + 2) << 16;
 210                 break;
 211         case OMAP_DMA_REG_32BIT:
 212                 val = readl_relaxed(addr);
 213                 break;
 214         default:
 215                 WARN_ON(1);
 216                 val = 0;
 217         }
 218
 219         return val;
 220 }
 221
 222 static void omap_dma_glbl_write(struct omap_dmadev *od, unsigned reg, unsigned val)
 223 {
 224         const struct omap_dma_reg *r = od->reg_map + reg;
 225
 226         WARN_ON(r->stride);
 227
 228         omap_dma_write(val, r->type, od->base + r->offset);
 229 }
 230
 231 static unsigned omap_dma_glbl_read(struct omap_dmadev *od, unsigned reg)
 232 {
 233         const struct omap_dma_reg *r = od->reg_map + reg;
 234
 235         WARN_ON(r->stride);
 236
 237         return omap_dma_read(r->type, od->base + r->offset);
 238 }
 239
 240 static void omap_dma_chan_write(struct omap_chan *c, unsigned reg, unsigned val)
 241 {
 242         const struct omap_dma_reg *r = c->reg_map + reg;
 243
 244         omap_dma_write(val, r->type, c->channel_base + r->offset);
 245 }
 246
 247 static unsigned omap_dma_chan_read(struct omap_chan *c, unsigned reg)
 248 {
 249         const struct omap_dma_reg *r = c->reg_map + reg;
 250
 251         return omap_dma_read(r->type, c->channel_base + r->offset);
 252 }
 253
 254 static void omap_dma_clear_csr(struct omap_chan *c)
 255 {
 256         if (dma_omap1())
 257                 omap_dma_chan_read(c, CSR);
 258         else
 259                 omap_dma_chan_write(c, CSR, ~0);
 260 }
 261
 262 static unsigned omap_dma_get_csr(struct omap_chan *c)
 263 {
 264         unsigned val = omap_dma_chan_read(c, CSR);
 265
 266         if (!dma_omap1())
 267                 omap_dma_chan_write(c, CSR, val);
 268
 269         return val;
 270 }
 271
 272 static void omap_dma_assign(struct omap_dmadev *od, struct omap_chan *c,
 273         unsigned lch)
 274 {
 275         c->channel_base = od->base + od->plat->channel_stride * lch;
 276
 277         od->lch_map[lch] = c;
 278 }
 279
 280 static void omap_dma_start(struct omap_chan *c, struct omap_desc *d)
 281 {
 282         struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
 283
 284         if (__dma_omap15xx(od->plat->dma_attr))
 285                 omap_dma_chan_write(c, CPC, 0);
 286         else
 287                 omap_dma_chan_write(c, CDAC, 0);
 288
 289         omap_dma_clear_csr(c);
 290
 291         /* Enable interrupts */
 292         omap_dma_chan_write(c, CICR, d->cicr);
 293
 294         /* Enable channel */
 295         omap_dma_chan_write(c, CCR, d->ccr | CCR_ENABLE);
 296 }
 297
 298 static void omap_dma_stop(struct omap_chan *c)
 299 {
 300         struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
 301         uint32_t val;
 302
 303         /* disable irq */
 304         omap_dma_chan_write(c, CICR, 0);
 305
 306         omap_dma_clear_csr(c);
 307
 308         val = omap_dma_chan_read(c, CCR);
 309         if (od->plat->errata & DMA_ERRATA_i541 && val & CCR_TRIGGER_SRC) {
 310                 uint32_t sysconfig;
 311                 unsigned i;
 312
 313                 sysconfig = omap_dma_glbl_read(od, OCP_SYSCONFIG);
 314                 val = sysconfig & ~DMA_SYSCONFIG_MIDLEMODE_MASK;
 315                 val |= DMA_SYSCONFIG_MIDLEMODE(DMA_IDLEMODE_NO_IDLE);
 316                 omap_dma_glbl_write(od, OCP_SYSCONFIG, val);
 317
 318                 val = omap_dma_chan_read(c, CCR);
 319                 val &= ~CCR_ENABLE;
 320                 omap_dma_chan_write(c, CCR, val);
 321
 322                 /* Wait for sDMA FIFO to drain */
 323                 for (i = 0; ; i++) {
 324                         val = omap_dma_chan_read(c, CCR);
 325                         if (!(val & (CCR_RD_ACTIVE | CCR_WR_ACTIVE)))
 326                                 break;
 327
 328                         if (i > 100)
 329                                 break;
 330
 331                         udelay(5);
 332                 }
 333
 334                 if (val & (CCR_RD_ACTIVE | CCR_WR_ACTIVE))
 335                         dev_err(c->vc.chan.device->dev,
 336                                 "DMA drain did not complete on lch %d\n",
 337                                 c->dma_ch);
 338
 339                 omap_dma_glbl_write(od, OCP_SYSCONFIG, sysconfig);
 340         } else {
 341                 val &= ~CCR_ENABLE;
 342                 omap_dma_chan_write(c, CCR, val);
 343         }
 344
 345         mb();
 346
 347         if (!__dma_omap15xx(od->plat->dma_attr) && c->cyclic) {
 348                 val = omap_dma_chan_read(c, CLNK_CTRL);
 349
 350                 if (dma_omap1())
 351                         val |= 1 << 14; /* set the STOP_LNK bit */
 352                 else
 353                         val &= ~CLNK_CTRL_ENABLE_LNK;
 354
 355                 omap_dma_chan_write(c, CLNK_CTRL, val);
 356         }
 357 }
 358
 359 static void omap_dma_start_sg(struct omap_chan *c, struct omap_desc *d,
 360         unsigned idx)
 361 {
 362         struct omap_sg *sg = d->sg + idx;
 363         unsigned cxsa, cxei, cxfi;
 364
 365         if (d->dir == DMA_DEV_TO_MEM) {
 366                 cxsa = CDSA;
 367                 cxei = CDEI;
 368                 cxfi = CDFI;
 369         } else {
 370                 cxsa = CSSA;
 371                 cxei = CSEI;
 372                 cxfi = CSFI;
 373         }
 374
 375         omap_dma_chan_write(c, cxsa, sg->addr);
 376         omap_dma_chan_write(c, cxei, 0);
 377         omap_dma_chan_write(c, cxfi, 0);
 378         omap_dma_chan_write(c, CEN, sg->en);
 379         omap_dma_chan_write(c, CFN, sg->fn);
 380
 381         omap_dma_start(c, d);
 382 }
 383
 384 static void omap_dma_start_desc(struct omap_chan *c)
 385 {
 386         struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
 387         struct omap_desc *d;
 388         unsigned cxsa, cxei, cxfi;
 389
 390         if (!vd) {
 391                 c->desc = NULL;
 392                 return;
 393         }
 394
 395         list_del(&vd->node);
 396
 397         c->desc = d = to_omap_dma_desc(&vd->tx);
 398         c->sgidx = 0;
 399
 400         /*
 401          * This provides the necessary barrier to ensure data held in
 402          * DMA coherent memory is visible to the DMA engine prior to
 403          * the transfer starting.
 404          */
 405         mb();
 406
 407         omap_dma_chan_write(c, CCR, d->ccr);
 408         if (dma_omap1())
 409                 omap_dma_chan_write(c, CCR2, d->ccr >> 16);
 410
 411         if (d->dir == DMA_DEV_TO_MEM) {
 412                 cxsa = CSSA;
 413                 cxei = CSEI;
 414                 cxfi = CSFI;
 415         } else {
 416                 cxsa = CDSA;
 417                 cxei = CDEI;
 418                 cxfi = CDFI;
 419         }
 420
 421         omap_dma_chan_write(c, cxsa, d->dev_addr);
 422         omap_dma_chan_write(c, cxei, 0);
 423         omap_dma_chan_write(c, cxfi, d->fi);
 424         omap_dma_chan_write(c, CSDP, d->csdp);
 425         omap_dma_chan_write(c, CLNK_CTRL, d->clnk_ctrl);
 426
 427         omap_dma_start_sg(c, d, 0);
 428 }
 429
 430 static void omap_dma_callback(int ch, u16 status, void *data)
 431 {
 432         struct omap_chan *c = data;
 433         struct omap_desc *d;
 434         unsigned long flags;
 435
 436         spin_lock_irqsave(&c->vc.lock, flags);
 437         d = c->desc;
 438         if (d) {
 439                 if (!c->cyclic) {
 440                         if (++c->sgidx < d->sglen) {
 441                                 omap_dma_start_sg(c, d, c->sgidx);
 442                         } else {
 443                                 omap_dma_start_desc(c);
 444                                 vchan_cookie_complete(&d->vd);
 445                         }
 446                 } else {
 447                         vchan_cyclic_callback(&d->vd);
 448                 }
 449         }
 450         spin_unlock_irqrestore(&c->vc.lock, flags);
 451 }
 452
 453 /*
 454  * This callback schedules all pending channels.  We could be more
 455  * clever here by postponing allocation of the real DMA channels to
 456  * this point, and freeing them when our virtual channel becomes idle.
 457  *
 458  * We would then need to deal with 'all channels in-use'
 459  */
 460 static void omap_dma_sched(unsigned long data)
 461 {
 462         struct omap_dmadev *d = (struct omap_dmadev *)data;
 463         LIST_HEAD(head);
 464
 465         spin_lock_irq(&d->lock);
 466         list_splice_tail_init(&d->pending, &head);
 467         spin_unlock_irq(&d->lock);
 468
 469         while (!list_empty(&head)) {
 470                 struct omap_chan *c = list_first_entry(&head,
 471                         struct omap_chan, node);
 472
 473                 spin_lock_irq(&c->vc.lock);
 474                 list_del_init(&c->node);
 475                 omap_dma_start_desc(c);
 476                 spin_unlock_irq(&c->vc.lock);
 477         }
 478 }
 479
 480 static irqreturn_t omap_dma_irq(int irq, void *devid)
 481 {
 482         struct omap_dmadev *od = devid;
 483         unsigned status, channel;
 484
 485         spin_lock(&od->irq_lock);
 486
 487         status = omap_dma_glbl_read(od, IRQSTATUS_L1);
 488         status &= od->irq_enable_mask;
 489         if (status == 0) {
 490                 spin_unlock(&od->irq_lock);
 491                 return IRQ_NONE;
 492         }
 493
 494         while ((channel = ffs(status)) != 0) {
 495                 unsigned mask, csr;
 496                 struct omap_chan *c;
 497
 498                 channel -= 1;
 499                 mask = BIT(channel);
 500                 status &= ~mask;
 501
 502                 c = od->lch_map[channel];
 503                 if (c == NULL) {
 504                         /* This should never happen */
 505                         dev_err(od->ddev.dev, "invalid channel %u\n", channel);
 506                         continue;
 507                 }
 508
 509                 csr = omap_dma_get_csr(c);
 510                 omap_dma_glbl_write(od, IRQSTATUS_L1, mask);
 511
 512                 omap_dma_callback(channel, csr, c);
 513         }
 514
 515         spin_unlock(&od->irq_lock);
 516
 517         return IRQ_HANDLED;
 518 }
 519
 520 static int omap_dma_alloc_chan_resources(struct dma_chan *chan)
 521 {
 522         struct omap_dmadev *od = to_omap_dma_dev(chan->device);
 523         struct omap_chan *c = to_omap_dma_chan(chan);
 524         int ret;
 525
 526         if (od->legacy) {
 527                 ret = omap_request_dma(c->dma_sig, "DMA engine",
 528                                        omap_dma_callback, c, &c->dma_ch);
 529         } else {
 530                 ret = omap_request_dma(c->dma_sig, "DMA engine", NULL, NULL,
 531                                        &c->dma_ch);
 532         }
 533
 534         dev_dbg(od->ddev.dev, "allocating channel %u for %u\n",
 535                 c->dma_ch, c->dma_sig);
 536
 537         if (ret >= 0) {
 538                 omap_dma_assign(od, c, c->dma_ch);
 539
 540                 if (!od->legacy) {
 541                         unsigned val;
 542
 543                         spin_lock_irq(&od->irq_lock);
 544                         val = BIT(c->dma_ch);
 545                         omap_dma_glbl_write(od, IRQSTATUS_L1, val);
 546                         od->irq_enable_mask |= val;
 547                         omap_dma_glbl_write(od, IRQENABLE_L1, od->irq_enable_mask);
 548
 549                         val = omap_dma_glbl_read(od, IRQENABLE_L0);
 550                         val &= ~BIT(c->dma_ch);
 551                         omap_dma_glbl_write(od, IRQENABLE_L0, val);
 552                         spin_unlock_irq(&od->irq_lock);
 553                 }
 554         }
 555
 556         if (dma_omap1()) {
 557                 if (__dma_omap16xx(od->plat->dma_attr)) {
 558                         c->ccr = CCR_OMAP31_DISABLE;
 559                         /* Duplicate what plat-omap/dma.c does */
 560                         c->ccr |= c->dma_ch + 1;
 561                 } else {
 562                         c->ccr = c->dma_sig & 0x1f;
 563                 }
 564         } else {
 565                 c->ccr = c->dma_sig & 0x1f;
 566                 c->ccr |= (c->dma_sig & ~0x1f) << 14;
 567         }
 568         if (od->plat->errata & DMA_ERRATA_IFRAME_BUFFERING)
 569                 c->ccr |= CCR_BUFFERING_DISABLE;
 570
 571         return ret;
 572 }
 573
 574 static void omap_dma_free_chan_resources(struct dma_chan *chan)
 575 {
 576         struct omap_dmadev *od = to_omap_dma_dev(chan->device);
 577         struct omap_chan *c = to_omap_dma_chan(chan);
 578
 579         if (!od->legacy) {
 580                 spin_lock_irq(&od->irq_lock);
 581                 od->irq_enable_mask &= ~BIT(c->dma_ch);
 582                 omap_dma_glbl_write(od, IRQENABLE_L1, od->irq_enable_mask);
 583                 spin_unlock_irq(&od->irq_lock);
 584         }
 585
 586         c->channel_base = NULL;
 587         od->lch_map[c->dma_ch] = NULL;
 588         vchan_free_chan_resources(&c->vc);
 589         omap_free_dma(c->dma_ch);
 590
 591         dev_dbg(od->ddev.dev, "freeing channel for %u\n", c->dma_sig);
 592 }
 593
 594 static size_t omap_dma_sg_size(struct omap_sg *sg)
 595 {
 596         return sg->en * sg->fn;
 597 }
 598
 599 static size_t omap_dma_desc_size(struct omap_desc *d)
 600 {
 601         unsigned i;
 602         size_t size;
 603
 604         for (size = i = 0; i < d->sglen; i++)
 605                 size += omap_dma_sg_size(&d->sg[i]);
 606
 607         return size * es_bytes[d->es];
 608 }
 609
 610 static size_t omap_dma_desc_size_pos(struct omap_desc *d, dma_addr_t addr)
 611 {
 612         unsigned i;
 613         size_t size, es_size = es_bytes[d->es];
 614
 615         for (size = i = 0; i < d->sglen; i++) {
 616                 size_t this_size = omap_dma_sg_size(&d->sg[i]) * es_size;
 617
 618                 if (size)
 619                         size += this_size;
 620                 else if (addr >= d->sg[i].addr &&
 621                          addr < d->sg[i].addr + this_size)
 622                         size += d->sg[i].addr + this_size - addr;
 623         }
 624         return size;
 625 }
 626
 627 /*
 628  * OMAP 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is
 629  * read before the DMA controller finished disabling the channel.
 630  */
 631 static uint32_t omap_dma_chan_read_3_3(struct omap_chan *c, unsigned reg)
 632 {
 633         struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
 634         uint32_t val;
 635
 636         val = omap_dma_chan_read(c, reg);
 637         if (val == 0 && od->plat->errata & DMA_ERRATA_3_3)
 638                 val = omap_dma_chan_read(c, reg);
 639
 640         return val;
 641 }
 642
 643 static dma_addr_t omap_dma_get_src_pos(struct omap_chan *c)
 644 {
 645         struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
 646         dma_addr_t addr, cdac;
 647
 648         if (__dma_omap15xx(od->plat->dma_attr)) {
 649                 addr = omap_dma_chan_read(c, CPC);
 650         } else {
 651                 addr = omap_dma_chan_read_3_3(c, CSAC);
 652                 cdac = omap_dma_chan_read_3_3(c, CDAC);
 653
 654                 /*
 655                  * CDAC == 0 indicates that the DMA transfer on the channel has
 656                  * not been started (no data has been transferred so far).
 657                  * Return the programmed source start address in this case.
 658                  */
 659                 if (cdac == 0)
 660                         addr = omap_dma_chan_read(c, CSSA);
 661         }
 662
 663         if (dma_omap1())
 664                 addr |= omap_dma_chan_read(c, CSSA) & 0xffff0000;
 665
 666         return addr;
 667 }
 668
 669 static dma_addr_t omap_dma_get_dst_pos(struct omap_chan *c)
 670 {
 671         struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
 672         dma_addr_t addr;
 673
 674         if (__dma_omap15xx(od->plat->dma_attr)) {
 675                 addr = omap_dma_chan_read(c, CPC);
 676         } else {
 677                 addr = omap_dma_chan_read_3_3(c, CDAC);
 678
 679                 /*
 680                  * CDAC == 0 indicates that the DMA transfer on the channel
 681                  * has not been started (no data has been transferred so
 682                  * far).  Return the programmed destination start address in
 683                  * this case.
 684                  */
 685                 if (addr == 0)
 686                         addr = omap_dma_chan_read(c, CDSA);
 687         }
 688
 689         if (dma_omap1())
 690                 addr |= omap_dma_chan_read(c, CDSA) & 0xffff0000;
 691
 692         return addr;
 693 }
 694
 695 static enum dma_status omap_dma_tx_status(struct dma_chan *chan,
 696         dma_cookie_t cookie, struct dma_tx_state *txstate)
 697 {
 698         struct omap_chan *c = to_omap_dma_chan(chan);
 699         struct virt_dma_desc *vd;
 700         enum dma_status ret;
 701         unsigned long flags;
 702
 703         ret = dma_cookie_status(chan, cookie, txstate);
 704         if (ret == DMA_COMPLETE || !txstate)
 705                 return ret;
 706
 707         spin_lock_irqsave(&c->vc.lock, flags);
 708         vd = vchan_find_desc(&c->vc, cookie);
 709         if (vd) {
 710                 txstate->residue = omap_dma_desc_size(to_omap_dma_desc(&vd->tx));
 711         } else if (c->desc && c->desc->vd.tx.cookie == cookie) {
 712                 struct omap_desc *d = c->desc;
 713                 dma_addr_t pos;
 714
 715                 if (d->dir == DMA_MEM_TO_DEV)
 716                         pos = omap_dma_get_src_pos(c);
 717                 else if (d->dir == DMA_DEV_TO_MEM)
 718                         pos = omap_dma_get_dst_pos(c);
 719                 else
 720                         pos = 0;
 721
 722                 txstate->residue = omap_dma_desc_size_pos(d, pos);
 723         } else {
 724                 txstate->residue = 0;
 725         }
 726         spin_unlock_irqrestore(&c->vc.lock, flags);
 727
 728         return ret;
 729 }
 730
 731 static void omap_dma_issue_pending(struct dma_chan *chan)
 732 {
 733         struct omap_chan *c = to_omap_dma_chan(chan);
 734         unsigned long flags;
 735
 736         spin_lock_irqsave(&c->vc.lock, flags);
 737         if (vchan_issue_pending(&c->vc) && !c->desc) {
 738                 /*
 739                  * c->cyclic is used only by audio and in this case the DMA need
 740                  * to be started without delay.
 741                  */
 742                 if (!c->cyclic) {
 743                         struct omap_dmadev *d = to_omap_dma_dev(chan->device);
 744                         spin_lock(&d->lock);
 745                         if (list_empty(&c->node))
 746                                 list_add_tail(&c->node, &d->pending);
 747                         spin_unlock(&d->lock);
 748                         tasklet_schedule(&d->task);
 749                 } else {
 750                         omap_dma_start_desc(c);
 751                 }
 752         }
 753         spin_unlock_irqrestore(&c->vc.lock, flags);
 754 }
 755
 756 static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
 757         struct dma_chan *chan, struct scatterlist *sgl, unsigned sglen,
 758         enum dma_transfer_direction dir, unsigned long tx_flags, void *context)
 759 {
 760         struct omap_dmadev *od = to_omap_dma_dev(chan->device);
 761         struct omap_chan *c = to_omap_dma_chan(chan);
 762         enum dma_slave_buswidth dev_width;
 763         struct scatterlist *sgent;
 764         struct omap_desc *d;
 765         dma_addr_t dev_addr;
 766         unsigned i, j = 0, es, en, frame_bytes;
 767         u32 burst;
 768
 769         if (dir == DMA_DEV_TO_MEM) {
 770                 dev_addr = c->cfg.src_addr;
 771                 dev_width = c->cfg.src_addr_width;
 772                 burst = c->cfg.src_maxburst;
 773         } else if (dir == DMA_MEM_TO_DEV) {
 774                 dev_addr = c->cfg.dst_addr;
 775                 dev_width = c->cfg.dst_addr_width;
 776                 burst = c->cfg.dst_maxburst;
 777         } else {
 778                 dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
 779                 return NULL;
 780         }
 781
 782         /* Bus width translates to the element size (ES) */
 783         switch (dev_width) {
 784         case DMA_SLAVE_BUSWIDTH_1_BYTE:
 785                 es = CSDP_DATA_TYPE_8;
 786                 break;
 787         case DMA_SLAVE_BUSWIDTH_2_BYTES:
 788                 es = CSDP_DATA_TYPE_16;
 789                 break;
 790         case DMA_SLAVE_BUSWIDTH_4_BYTES:
 791                 es = CSDP_DATA_TYPE_32;
 792                 break;
 793         default: /* not reached */
 794                 return NULL;
 795         }
 796
 797         /* Now allocate and setup the descriptor. */
 798         d = kzalloc(sizeof(*d) + sglen * sizeof(d->sg[0]), GFP_ATOMIC);
 799         if (!d)
 800                 return NULL;
 801
 802         d->dir = dir;
 803         d->dev_addr = dev_addr;
 804         d->es = es;
 805
 806         d->ccr = c->ccr | CCR_SYNC_FRAME;
 807         if (dir == DMA_DEV_TO_MEM)
 808                 d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_CONSTANT;
 809         else
 810                 d->ccr |= CCR_DST_AMODE_CONSTANT | CCR_SRC_AMODE_POSTINC;
 811
 812         d->cicr = CICR_DROP_IE | CICR_BLOCK_IE;
 813         d->csdp = es;
 814
 815         if (dma_omap1()) {
 816                 d->cicr |= CICR_TOUT_IE;
 817
 818                 if (dir == DMA_DEV_TO_MEM)
 819                         d->csdp |= CSDP_DST_PORT_EMIFF | CSDP_SRC_PORT_TIPB;
 820                 else
 821                         d->csdp |= CSDP_DST_PORT_TIPB | CSDP_SRC_PORT_EMIFF;
 822         } else {
 823                 if (dir == DMA_DEV_TO_MEM)
 824                         d->ccr |= CCR_TRIGGER_SRC;
 825
 826                 d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
 827         }
 828         if (od->plat->errata & DMA_ERRATA_PARALLEL_CHANNELS)
 829                 d->clnk_ctrl = c->dma_ch;
 830
 831         /*
 832          * Build our scatterlist entries: each contains the address,
 833          * the number of elements (EN) in each frame, and the number of
 834          * frames (FN).  Number of bytes for this entry = ES * EN * FN.
 835          *
 836          * Burst size translates to number of elements with frame sync.
 837          * Note: DMA engine defines burst to be the number of dev-width
 838          * transfers.
 839          */
 840         en = burst;
 841         frame_bytes = es_bytes[es] * en;
 842         for_each_sg(sgl, sgent, sglen, i) {
 843                 d->sg[j].addr = sg_dma_address(sgent);
 844                 d->sg[j].en = en;
 845                 d->sg[j].fn = sg_dma_len(sgent) / frame_bytes;
 846                 j++;
 847         }
 848
 849         d->sglen = j;
 850
 851         return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
 852 }
 853
 854 static struct dma_async_tx_descriptor *omap_dma_prep_dma_cyclic(
 855         struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
 856         size_t period_len, enum dma_transfer_direction dir, unsigned long flags)
 857 {
 858         struct omap_dmadev *od = to_omap_dma_dev(chan->device);
 859         struct omap_chan *c = to_omap_dma_chan(chan);
 860         enum dma_slave_buswidth dev_width;
 861         struct omap_desc *d;
 862         dma_addr_t dev_addr;
 863         unsigned es;
 864         u32 burst;
 865
 866         if (dir == DMA_DEV_TO_MEM) {
 867                 dev_addr = c->cfg.src_addr;
 868                 dev_width = c->cfg.src_addr_width;
 869                 burst = c->cfg.src_maxburst;
 870         } else if (dir == DMA_MEM_TO_DEV) {
 871                 dev_addr = c->cfg.dst_addr;
 872                 dev_width = c->cfg.dst_addr_width;
 873                 burst = c->cfg.dst_maxburst;
 874         } else {
 875                 dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
 876                 return NULL;
 877         }
 878
 879         /* Bus width translates to the element size (ES) */
 880         switch (dev_width) {
 881         case DMA_SLAVE_BUSWIDTH_1_BYTE:
 882                 es = CSDP_DATA_TYPE_8;
 883                 break;
 884         case DMA_SLAVE_BUSWIDTH_2_BYTES:
 885                 es = CSDP_DATA_TYPE_16;
 886                 break;
 887         case DMA_SLAVE_BUSWIDTH_4_BYTES:
 888                 es = CSDP_DATA_TYPE_32;
 889                 break;
 890         default: /* not reached */
 891                 return NULL;
 892         }
 893
 894         /* Now allocate and setup the descriptor. */
 895         d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC);
 896         if (!d)
 897                 return NULL;
 898
 899         d->dir = dir;
 900         d->dev_addr = dev_addr;
 901         d->fi = burst;
 902         d->es = es;
 903         d->sg[0].addr = buf_addr;
 904         d->sg[0].en = period_len / es_bytes[es];
 905         d->sg[0].fn = buf_len / period_len;
 906         d->sglen = 1;
 907
 908         d->ccr = c->ccr;
 909         if (dir == DMA_DEV_TO_MEM)
 910                 d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_CONSTANT;
 911         else
 912                 d->ccr |= CCR_DST_AMODE_CONSTANT | CCR_SRC_AMODE_POSTINC;
 913
 914         d->cicr = CICR_DROP_IE;
 915         if (flags & DMA_PREP_INTERRUPT)
 916                 d->cicr |= CICR_FRAME_IE;
 917
 918         d->csdp = es;
 919
 920         if (dma_omap1()) {
 921                 d->cicr |= CICR_TOUT_IE;
 922
 923                 if (dir == DMA_DEV_TO_MEM)
 924                         d->csdp |= CSDP_DST_PORT_EMIFF | CSDP_SRC_PORT_MPUI;
 925                 else
 926                         d->csdp |= CSDP_DST_PORT_MPUI | CSDP_SRC_PORT_EMIFF;
 927         } else {
 928                 if (burst)
 929                         d->ccr |= CCR_SYNC_PACKET;
 930                 else
 931                         d->ccr |= CCR_SYNC_ELEMENT;
 932
 933                 if (dir == DMA_DEV_TO_MEM)
 934                         d->ccr |= CCR_TRIGGER_SRC;
 935
 936                 d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
 937
 938                 d->csdp |= CSDP_DST_BURST_64 | CSDP_SRC_BURST_64;
 939         }
 940
 941         if (__dma_omap15xx(od->plat->dma_attr))
 942                 d->ccr |= CCR_AUTO_INIT | CCR_REPEAT;
 943         else
 944                 d->clnk_ctrl = c->dma_ch | CLNK_CTRL_ENABLE_LNK;
 945
 946         c->cyclic = true;
 947
 948         return vchan_tx_prep(&c->vc, &d->vd, flags);
 949 }
 950
 951 static int omap_dma_slave_config(struct omap_chan *c, struct dma_slave_config *cfg)
 952 {
 953         if (cfg->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
 954             cfg->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
 955                 return -EINVAL;
 956
 957         memcpy(&c->cfg, cfg, sizeof(c->cfg));
 958
 959         return 0;
 960 }
 961
 962 static int omap_dma_terminate_all(struct omap_chan *c)
 963 {
 964         struct omap_dmadev *d = to_omap_dma_dev(c->vc.chan.device);
 965         unsigned long flags;
 966         LIST_HEAD(head);
 967
 968         spin_lock_irqsave(&c->vc.lock, flags);
 969
 970         /* Prevent this channel being scheduled */
 971         spin_lock(&d->lock);
 972         list_del_init(&c->node);
 973         spin_unlock(&d->lock);
 974
 975         /*
 976          * Stop DMA activity: we assume the callback will not be called
 977          * after omap_dma_stop() returns (even if it does, it will see
 978          * c->desc is NULL and exit.)
 979          */
 980         if (c->desc) {
 981                 c->desc = NULL;
 982                 /* Avoid stopping the dma twice */
 983                 if (!c->paused)
 984                         omap_dma_stop(c);
 985         }
 986
 987         if (c->cyclic) {
 988                 c->cyclic = false;
 989                 c->paused = false;
 990         }
 991
 992         vchan_get_all_descriptors(&c->vc, &head);
 993         spin_unlock_irqrestore(&c->vc.lock, flags);
 994         vchan_dma_desc_free_list(&c->vc, &head);
 995
 996         return 0;
 997 }
 998
 999 static int omap_dma_pause(struct omap_chan *c)
1000 {
1001         /* Pause/Resume only allowed with cyclic mode */
1002         if (!c->cyclic)
1003                 return -EINVAL;
1004
1005         if (!c->paused) {
1006                 omap_dma_stop(c);
1007                 c->paused = true;
1008         }
1009
1010         return 0;
1011 }
1012
1013 static int omap_dma_resume(struct omap_chan *c)
1014 {
1015         /* Pause/Resume only allowed with cyclic mode */
1016         if (!c->cyclic)
1017                 return -EINVAL;
1018
1019         if (c->paused) {
1020                 mb();
1021
1022                 /* Restore channel link register */
1023                 omap_dma_chan_write(c, CLNK_CTRL, c->desc->clnk_ctrl);
1024
1025                 omap_dma_start(c, c->desc);
1026                 c->paused = false;
1027         }
1028
1029         return 0;
1030 }
1031
1032 static int omap_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
1033         unsigned long arg)
1034 {
1035         struct omap_chan *c = to_omap_dma_chan(chan);
1036         int ret;
1037
1038         switch (cmd) {
1039         case DMA_SLAVE_CONFIG:
1040                 ret = omap_dma_slave_config(c, (struct dma_slave_config *)arg);
1041                 break;
1042
1043         case DMA_TERMINATE_ALL:
1044                 ret = omap_dma_terminate_all(c);
1045                 break;
1046
1047         case DMA_PAUSE:
1048                 ret = omap_dma_pause(c);
1049                 break;
1050
1051         case DMA_RESUME:
1052                 ret = omap_dma_resume(c);
1053                 break;
1054
1055         default:
1056                 ret = -ENXIO;
1057                 break;
1058         }
1059
1060         return ret;
1061 }
1062
1063 static int omap_dma_chan_init(struct omap_dmadev *od, int dma_sig)
1064 {
1065         struct omap_chan *c;
1066
1067         c = kzalloc(sizeof(*c), GFP_KERNEL);
1068         if (!c)
1069                 return -ENOMEM;
1070
1071         c->reg_map = od->reg_map;
1072         c->dma_sig = dma_sig;
1073         c->vc.desc_free = omap_dma_desc_free;
1074         vchan_init(&c->vc, &od->ddev);
1075         INIT_LIST_HEAD(&c->node);
1076
1077         return 0;
1078 }
1079
1080 static void omap_dma_free(struct omap_dmadev *od)
1081 {
1082         tasklet_kill(&od->task);
1083         while (!list_empty(&od->ddev.channels)) {
1084                 struct omap_chan *c = list_first_entry(&od->ddev.channels,
1085                         struct omap_chan, vc.chan.device_node);
1086
1087                 list_del(&c->vc.chan.device_node);
1088                 tasklet_kill(&c->vc.task);
1089                 kfree(c);
1090         }
1091 }
1092
1093 #define OMAP_DMA_BUSWIDTHS      (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
1094                                  BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
1095                                  BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
1096
1097 static int omap_dma_device_slave_caps(struct dma_chan *dchan,
1098                                       struct dma_slave_caps *caps)
1099 {
1100         caps->src_addr_widths = OMAP_DMA_BUSWIDTHS;
1101         caps->dstn_addr_widths = OMAP_DMA_BUSWIDTHS;
1102         caps->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1103         caps->cmd_pause = true;
1104         caps->cmd_terminate = true;
1105         caps->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1106
1107         return 0;
1108 }
1109
1110 static int omap_dma_probe(struct platform_device *pdev)
1111 {
1112         struct omap_dmadev *od;
1113         struct resource *res;
1114         int rc, i, irq;
1115
1116         od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL);
1117         if (!od)
1118                 return -ENOMEM;
1119
1120         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1121         od->base = devm_ioremap_resource(&pdev->dev, res);
1122         if (IS_ERR(od->base))
1123                 return PTR_ERR(od->base);
1124
1125         od->plat = omap_get_plat_info();
1126         if (!od->plat)
1127                 return -EPROBE_DEFER;
1128
1129         od->reg_map = od->plat->reg_map;
1130
1131         dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
1132         dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask);
1133         od->ddev.device_alloc_chan_resources = omap_dma_alloc_chan_resources;
1134         od->ddev.device_free_chan_resources = omap_dma_free_chan_resources;
1135         od->ddev.device_tx_status = omap_dma_tx_status;
1136         od->ddev.device_issue_pending = omap_dma_issue_pending;
1137         od->ddev.device_prep_slave_sg = omap_dma_prep_slave_sg;
1138         od->ddev.device_prep_dma_cyclic = omap_dma_prep_dma_cyclic;
1139         od->ddev.device_control = omap_dma_control;
1140         od->ddev.device_slave_caps = omap_dma_device_slave_caps;
1141         od->ddev.dev = &pdev->dev;
1142         INIT_LIST_HEAD(&od->ddev.channels);
1143         INIT_LIST_HEAD(&od->pending);
1144         spin_lock_init(&od->lock);
1145         spin_lock_init(&od->irq_lock);
1146
1147         tasklet_init(&od->task, omap_dma_sched, (unsigned long)od);
1148
1149         for (i = 0; i < 127; i++) {
1150                 rc = omap_dma_chan_init(od, i);
1151                 if (rc) {
1152                         omap_dma_free(od);
1153                         return rc;
1154                 }
1155         }
1156
1157         irq = platform_get_irq(pdev, 1);
1158         if (irq <= 0) {
1159                 dev_info(&pdev->dev, "failed to get L1 IRQ: %d\n", irq);
1160                 od->legacy = true;
1161         } else {
1162                 /* Disable all interrupts */
1163                 od->irq_enable_mask = 0;
1164                 omap_dma_glbl_write(od, IRQENABLE_L1, 0);
1165
1166                 rc = devm_request_irq(&pdev->dev, irq, omap_dma_irq,
1167                                       IRQF_SHARED, "omap-dma-engine", od);
1168                 if (rc)
1169                         return rc;
1170         }
1171
1172         rc = dma_async_device_register(&od->ddev);
1173         if (rc) {
1174                 pr_warn("OMAP-DMA: failed to register slave DMA engine device: %d\n",
1175                         rc);
1176                 omap_dma_free(od);
1177                 return rc;
1178         }
1179
1180         platform_set_drvdata(pdev, od);
1181
1182         if (pdev->dev.of_node) {
1183                 omap_dma_info.dma_cap = od->ddev.cap_mask;
1184
1185                 /* Device-tree DMA controller registration */
1186                 rc = of_dma_controller_register(pdev->dev.of_node,
1187                                 of_dma_simple_xlate, &omap_dma_info);
1188                 if (rc) {
1189                         pr_warn("OMAP-DMA: failed to register DMA controller\n");
1190                         dma_async_device_unregister(&od->ddev);
1191                         omap_dma_free(od);
1192                 }
1193         }
1194
1195         dev_info(&pdev->dev, "OMAP DMA engine driver\n");
1196
1197         return rc;
1198 }
1199
1200 static int omap_dma_remove(struct platform_device *pdev)
1201 {
1202         struct omap_dmadev *od = platform_get_drvdata(pdev);
1203
1204         if (pdev->dev.of_node)
1205                 of_dma_controller_free(pdev->dev.of_node);
1206
1207         dma_async_device_unregister(&od->ddev);
1208
1209         if (!od->legacy) {
1210                 /* Disable all interrupts */
1211                 omap_dma_glbl_write(od, IRQENABLE_L0, 0);
1212         }
1213
1214         omap_dma_free(od);
1215
1216         return 0;
1217 }
1218
1219 static const struct of_device_id omap_dma_match[] = {
1220         { .compatible = "ti,omap2420-sdma", },
1221         { .compatible = "ti,omap2430-sdma", },
1222         { .compatible = "ti,omap3430-sdma", },
1223         { .compatible = "ti,omap3630-sdma", },
1224         { .compatible = "ti,omap4430-sdma", },
1225         {},
1226 };
1227 MODULE_DEVICE_TABLE(of, omap_dma_match);
1228
1229 static struct platform_driver omap_dma_driver = {
1230         .probe  = omap_dma_probe,
1231         .remove = omap_dma_remove,
1232         .driver = {
1233                 .name = "omap-dma-engine",
1234                 .of_match_table = of_match_ptr(omap_dma_match),
1235         },
1236 };
1237
1238 bool omap_dma_filter_fn(struct dma_chan *chan, void *param)
1239 {
1240         if (chan->device->dev->driver == &omap_dma_driver.driver) {
1241                 struct omap_chan *c = to_omap_dma_chan(chan);
1242                 unsigned req = *(unsigned *)param;
1243
1244                 return req == c->dma_sig;
1245         }
1246         return false;
1247 }
1248 EXPORT_SYMBOL_GPL(omap_dma_filter_fn);
1249
1250 static int omap_dma_init(void)
1251 {
1252         return platform_driver_register(&omap_dma_driver);
1253 }
1254 subsys_initcall(omap_dma_init);
1255
1256 static void __exit omap_dma_exit(void)
1257 {
1258         platform_driver_unregister(&omap_dma_driver);
1259 }
1260 module_exit(omap_dma_exit);
1261
1262 MODULE_AUTHOR("Russell King");
1263 MODULE_LICENSE("GPL");