1 /* 2 * MOXA ART SoCs DMA Engine support. 3 * 4 * Copyright (C) 2013 Jonas Jensen 5 * 6 * Jonas Jensen <jonas.jensen@gmail.com> 7 * 8 * This file is licensed under the terms of the GNU General Public 9 * License version 2. This program is licensed "as is" without any 10 * warranty of any kind, whether express or implied. 11 */ 12 13 #include <linux/dmaengine.h> 14 #include <linux/dma-mapping.h> 15 #include <linux/err.h> 16 #include <linux/init.h> 17 #include <linux/interrupt.h> 18 #include <linux/list.h> 19 #include <linux/module.h> 20 #include <linux/platform_device.h> 21 #include <linux/slab.h> 22 #include <linux/spinlock.h> 23 #include <linux/of_address.h> 24 #include <linux/of_irq.h> 25 #include <linux/of_dma.h> 26 #include <linux/bitops.h> 27 28 #include <asm/cacheflush.h> 29 30 #include "dmaengine.h" 31 #include "virt-dma.h" 32 33 #define APB_DMA_MAX_CHANNEL 4 34 35 #define REG_OFF_ADDRESS_SOURCE 0 36 #define REG_OFF_ADDRESS_DEST 4 37 #define REG_OFF_CYCLES 8 38 #define REG_OFF_CTRL 12 39 #define REG_OFF_CHAN_SIZE 16 40 41 #define APB_DMA_ENABLE BIT(0) 42 #define APB_DMA_FIN_INT_STS BIT(1) 43 #define APB_DMA_FIN_INT_EN BIT(2) 44 #define APB_DMA_BURST_MODE BIT(3) 45 #define APB_DMA_ERR_INT_STS BIT(4) 46 #define APB_DMA_ERR_INT_EN BIT(5) 47 48 /* 49 * Unset: APB 50 * Set: AHB 51 */ 52 #define APB_DMA_SOURCE_SELECT 0x40 53 #define APB_DMA_DEST_SELECT 0x80 54 55 #define APB_DMA_SOURCE 0x100 56 #define APB_DMA_DEST 0x1000 57 58 #define APB_DMA_SOURCE_MASK 0x700 59 #define APB_DMA_DEST_MASK 0x7000 60 61 /* 62 * 000: No increment 63 * 001: +1 (Burst=0), +4 (Burst=1) 64 * 010: +2 (Burst=0), +8 (Burst=1) 65 * 011: +4 (Burst=0), +16 (Burst=1) 66 * 101: -1 (Burst=0), -4 (Burst=1) 67 * 110: -2 (Burst=0), -8 (Burst=1) 68 * 111: -4 (Burst=0), -16 (Burst=1) 69 */ 70 #define APB_DMA_SOURCE_INC_0 0 71 #define APB_DMA_SOURCE_INC_1_4 0x100 72 #define APB_DMA_SOURCE_INC_2_8 0x200 73 #define APB_DMA_SOURCE_INC_4_16 0x300 74 #define APB_DMA_SOURCE_DEC_1_4 0x500 75 #define APB_DMA_SOURCE_DEC_2_8 0x600 76 #define APB_DMA_SOURCE_DEC_4_16 0x700 77 #define APB_DMA_DEST_INC_0 0 78 #define APB_DMA_DEST_INC_1_4 0x1000 79 #define APB_DMA_DEST_INC_2_8 0x2000 80 #define APB_DMA_DEST_INC_4_16 0x3000 81 #define APB_DMA_DEST_DEC_1_4 0x5000 82 #define APB_DMA_DEST_DEC_2_8 0x6000 83 #define APB_DMA_DEST_DEC_4_16 0x7000 84 85 /* 86 * Request signal select source/destination address for DMA hardware handshake. 87 * 88 * The request line number is a property of the DMA controller itself, 89 * e.g. MMC must always request channels where dma_slave_config->slave_id is 5. 90 * 91 * 0: No request / Grant signal 92 * 1-15: Request / Grant signal 93 */ 94 #define APB_DMA_SOURCE_REQ_NO 0x1000000 95 #define APB_DMA_SOURCE_REQ_NO_MASK 0xf000000 96 #define APB_DMA_DEST_REQ_NO 0x10000 97 #define APB_DMA_DEST_REQ_NO_MASK 0xf0000 98 99 #define APB_DMA_DATA_WIDTH 0x100000 100 #define APB_DMA_DATA_WIDTH_MASK 0x300000 101 /* 102 * Data width of transfer: 103 * 104 * 00: Word 105 * 01: Half 106 * 10: Byte 107 */ 108 #define APB_DMA_DATA_WIDTH_4 0 109 #define APB_DMA_DATA_WIDTH_2 0x100000 110 #define APB_DMA_DATA_WIDTH_1 0x200000 111 112 #define APB_DMA_CYCLES_MASK 0x00ffffff 113 114 #define MOXART_DMA_DATA_TYPE_S8 0x00 115 #define MOXART_DMA_DATA_TYPE_S16 0x01 116 #define MOXART_DMA_DATA_TYPE_S32 0x02 117 118 struct moxart_sg { 119 dma_addr_t addr; 120 uint32_t len; 121 }; 122 123 struct moxart_desc { 124 enum dma_transfer_direction dma_dir; 125 dma_addr_t dev_addr; 126 unsigned int sglen; 127 unsigned int dma_cycles; 128 struct virt_dma_desc vd; 129 uint8_t es; 130 struct moxart_sg sg[0]; 131 }; 132 133 struct moxart_chan { 134 struct virt_dma_chan vc; 135 136 void __iomem *base; 137 struct moxart_desc *desc; 138 139 struct dma_slave_config cfg; 140 141 bool allocated; 142 bool error; 143 int ch_num; 144 unsigned int line_reqno; 145 unsigned int sgidx; 146 }; 147 148 struct moxart_dmadev { 149 struct dma_device dma_slave; 150 struct moxart_chan slave_chans[APB_DMA_MAX_CHANNEL]; 151 }; 152 153 struct moxart_filter_data { 154 struct moxart_dmadev *mdc; 155 struct of_phandle_args *dma_spec; 156 }; 157 158 static const unsigned int es_bytes[] = { 159 [MOXART_DMA_DATA_TYPE_S8] = 1, 160 [MOXART_DMA_DATA_TYPE_S16] = 2, 161 [MOXART_DMA_DATA_TYPE_S32] = 4, 162 }; 163 164 static struct device *chan2dev(struct dma_chan *chan) 165 { 166 return &chan->dev->device; 167 } 168 169 static inline struct moxart_chan *to_moxart_dma_chan(struct dma_chan *c) 170 { 171 return container_of(c, struct moxart_chan, vc.chan); 172 } 173 174 static inline struct moxart_desc *to_moxart_dma_desc( 175 struct dma_async_tx_descriptor *t) 176 { 177 return container_of(t, struct moxart_desc, vd.tx); 178 } 179 180 static void moxart_dma_desc_free(struct virt_dma_desc *vd) 181 { 182 kfree(container_of(vd, struct moxart_desc, vd)); 183 } 184 185 static int moxart_terminate_all(struct dma_chan *chan) 186 { 187 struct moxart_chan *ch = to_moxart_dma_chan(chan); 188 unsigned long flags; 189 LIST_HEAD(head); 190 u32 ctrl; 191 192 dev_dbg(chan2dev(chan), "%s: ch=%p\n", __func__, ch); 193 194 spin_lock_irqsave(&ch->vc.lock, flags); 195 196 if (ch->desc) 197 ch->desc = NULL; 198 199 ctrl = readl(ch->base + REG_OFF_CTRL); 200 ctrl &= ~(APB_DMA_ENABLE | APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN); 201 writel(ctrl, ch->base + REG_OFF_CTRL); 202 203 vchan_get_all_descriptors(&ch->vc, &head); 204 spin_unlock_irqrestore(&ch->vc.lock, flags); 205 vchan_dma_desc_free_list(&ch->vc, &head); 206 207 return 0; 208 } 209 210 static int moxart_slave_config(struct dma_chan *chan, 211 struct dma_slave_config *cfg) 212 { 213 struct moxart_chan *ch = to_moxart_dma_chan(chan); 214 u32 ctrl; 215 216 ch->cfg = *cfg; 217 218 ctrl = readl(ch->base + REG_OFF_CTRL); 219 ctrl |= APB_DMA_BURST_MODE; 220 ctrl &= ~(APB_DMA_DEST_MASK | APB_DMA_SOURCE_MASK); 221 ctrl &= ~(APB_DMA_DEST_REQ_NO_MASK | APB_DMA_SOURCE_REQ_NO_MASK); 222 223 switch (ch->cfg.src_addr_width) { 224 case DMA_SLAVE_BUSWIDTH_1_BYTE: 225 ctrl |= APB_DMA_DATA_WIDTH_1; 226 if (ch->cfg.direction != DMA_MEM_TO_DEV) 227 ctrl |= APB_DMA_DEST_INC_1_4; 228 else 229 ctrl |= APB_DMA_SOURCE_INC_1_4; 230 break; 231 case DMA_SLAVE_BUSWIDTH_2_BYTES: 232 ctrl |= APB_DMA_DATA_WIDTH_2; 233 if (ch->cfg.direction != DMA_MEM_TO_DEV) 234 ctrl |= APB_DMA_DEST_INC_2_8; 235 else 236 ctrl |= APB_DMA_SOURCE_INC_2_8; 237 break; 238 case DMA_SLAVE_BUSWIDTH_4_BYTES: 239 ctrl &= ~APB_DMA_DATA_WIDTH; 240 if (ch->cfg.direction != DMA_MEM_TO_DEV) 241 ctrl |= APB_DMA_DEST_INC_4_16; 242 else 243 ctrl |= APB_DMA_SOURCE_INC_4_16; 244 break; 245 default: 246 return -EINVAL; 247 } 248 249 if (ch->cfg.direction == DMA_MEM_TO_DEV) { 250 ctrl &= ~APB_DMA_DEST_SELECT; 251 ctrl |= APB_DMA_SOURCE_SELECT; 252 ctrl |= (ch->line_reqno << 16 & 253 APB_DMA_DEST_REQ_NO_MASK); 254 } else { 255 ctrl |= APB_DMA_DEST_SELECT; 256 ctrl &= ~APB_DMA_SOURCE_SELECT; 257 ctrl |= (ch->line_reqno << 24 & 258 APB_DMA_SOURCE_REQ_NO_MASK); 259 } 260 261 writel(ctrl, ch->base + REG_OFF_CTRL); 262 263 return 0; 264 } 265 266 static int moxart_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, 267 unsigned long arg) 268 { 269 int ret = 0; 270 271 switch (cmd) { 272 case DMA_PAUSE: 273 case DMA_RESUME: 274 return -EINVAL; 275 case DMA_TERMINATE_ALL: 276 moxart_terminate_all(chan); 277 break; 278 case DMA_SLAVE_CONFIG: 279 ret = moxart_slave_config(chan, (struct dma_slave_config *)arg); 280 break; 281 default: 282 ret = -ENOSYS; 283 } 284 285 return ret; 286 } 287 288 static struct dma_async_tx_descriptor *moxart_prep_slave_sg( 289 struct dma_chan *chan, struct scatterlist *sgl, 290 unsigned int sg_len, enum dma_transfer_direction dir, 291 unsigned long tx_flags, void *context) 292 { 293 struct moxart_chan *ch = to_moxart_dma_chan(chan); 294 struct moxart_desc *d; 295 enum dma_slave_buswidth dev_width; 296 dma_addr_t dev_addr; 297 struct scatterlist *sgent; 298 unsigned int es; 299 unsigned int i; 300 301 if (!is_slave_direction(dir)) { 302 dev_err(chan2dev(chan), "%s: invalid DMA direction\n", 303 __func__); 304 return NULL; 305 } 306 307 if (dir == DMA_DEV_TO_MEM) { 308 dev_addr = ch->cfg.src_addr; 309 dev_width = ch->cfg.src_addr_width; 310 } else { 311 dev_addr = ch->cfg.dst_addr; 312 dev_width = ch->cfg.dst_addr_width; 313 } 314 315 switch (dev_width) { 316 case DMA_SLAVE_BUSWIDTH_1_BYTE: 317 es = MOXART_DMA_DATA_TYPE_S8; 318 break; 319 case DMA_SLAVE_BUSWIDTH_2_BYTES: 320 es = MOXART_DMA_DATA_TYPE_S16; 321 break; 322 case DMA_SLAVE_BUSWIDTH_4_BYTES: 323 es = MOXART_DMA_DATA_TYPE_S32; 324 break; 325 default: 326 dev_err(chan2dev(chan), "%s: unsupported data width (%u)\n", 327 __func__, dev_width); 328 return NULL; 329 } 330 331 d = kzalloc(sizeof(*d) + sg_len * sizeof(d->sg[0]), GFP_ATOMIC); 332 if (!d) 333 return NULL; 334 335 d->dma_dir = dir; 336 d->dev_addr = dev_addr; 337 d->es = es; 338 339 for_each_sg(sgl, sgent, sg_len, i) { 340 d->sg[i].addr = sg_dma_address(sgent); 341 d->sg[i].len = sg_dma_len(sgent); 342 } 343 344 d->sglen = sg_len; 345 346 ch->error = 0; 347 348 return vchan_tx_prep(&ch->vc, &d->vd, tx_flags); 349 } 350 351 static struct dma_chan *moxart_of_xlate(struct of_phandle_args *dma_spec, 352 struct of_dma *ofdma) 353 { 354 struct moxart_dmadev *mdc = ofdma->of_dma_data; 355 struct dma_chan *chan; 356 struct moxart_chan *ch; 357 358 chan = dma_get_any_slave_channel(&mdc->dma_slave); 359 if (!chan) 360 return NULL; 361 362 ch = to_moxart_dma_chan(chan); 363 ch->line_reqno = dma_spec->args[0]; 364 365 return chan; 366 } 367 368 static int moxart_alloc_chan_resources(struct dma_chan *chan) 369 { 370 struct moxart_chan *ch = to_moxart_dma_chan(chan); 371 372 dev_dbg(chan2dev(chan), "%s: allocating channel #%u\n", 373 __func__, ch->ch_num); 374 ch->allocated = 1; 375 376 return 0; 377 } 378 379 static void moxart_free_chan_resources(struct dma_chan *chan) 380 { 381 struct moxart_chan *ch = to_moxart_dma_chan(chan); 382 383 vchan_free_chan_resources(&ch->vc); 384 385 dev_dbg(chan2dev(chan), "%s: freeing channel #%u\n", 386 __func__, ch->ch_num); 387 ch->allocated = 0; 388 } 389 390 static void moxart_dma_set_params(struct moxart_chan *ch, dma_addr_t src_addr, 391 dma_addr_t dst_addr) 392 { 393 writel(src_addr, ch->base + REG_OFF_ADDRESS_SOURCE); 394 writel(dst_addr, ch->base + REG_OFF_ADDRESS_DEST); 395 } 396 397 static void moxart_set_transfer_params(struct moxart_chan *ch, unsigned int len) 398 { 399 struct moxart_desc *d = ch->desc; 400 unsigned int sglen_div = es_bytes[d->es]; 401 402 d->dma_cycles = len >> sglen_div; 403 404 /* 405 * There are 4 cycles on 64 bytes copied, i.e. one cycle copies 16 406 * bytes ( when width is APB_DMAB_DATA_WIDTH_4 ). 407 */ 408 writel(d->dma_cycles, ch->base + REG_OFF_CYCLES); 409 410 dev_dbg(chan2dev(&ch->vc.chan), "%s: set %u DMA cycles (len=%u)\n", 411 __func__, d->dma_cycles, len); 412 } 413 414 static void moxart_start_dma(struct moxart_chan *ch) 415 { 416 u32 ctrl; 417 418 ctrl = readl(ch->base + REG_OFF_CTRL); 419 ctrl |= (APB_DMA_ENABLE | APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN); 420 writel(ctrl, ch->base + REG_OFF_CTRL); 421 } 422 423 static void moxart_dma_start_sg(struct moxart_chan *ch, unsigned int idx) 424 { 425 struct moxart_desc *d = ch->desc; 426 struct moxart_sg *sg = ch->desc->sg + idx; 427 428 if (ch->desc->dma_dir == DMA_MEM_TO_DEV) 429 moxart_dma_set_params(ch, sg->addr, d->dev_addr); 430 else if (ch->desc->dma_dir == DMA_DEV_TO_MEM) 431 moxart_dma_set_params(ch, d->dev_addr, sg->addr); 432 433 moxart_set_transfer_params(ch, sg->len); 434 435 moxart_start_dma(ch); 436 } 437 438 static void moxart_dma_start_desc(struct dma_chan *chan) 439 { 440 struct moxart_chan *ch = to_moxart_dma_chan(chan); 441 struct virt_dma_desc *vd; 442 443 vd = vchan_next_desc(&ch->vc); 444 445 if (!vd) { 446 ch->desc = NULL; 447 return; 448 } 449 450 list_del(&vd->node); 451 452 ch->desc = to_moxart_dma_desc(&vd->tx); 453 ch->sgidx = 0; 454 455 moxart_dma_start_sg(ch, 0); 456 } 457 458 static void moxart_issue_pending(struct dma_chan *chan) 459 { 460 struct moxart_chan *ch = to_moxart_dma_chan(chan); 461 unsigned long flags; 462 463 spin_lock_irqsave(&ch->vc.lock, flags); 464 if (vchan_issue_pending(&ch->vc) && !ch->desc) 465 moxart_dma_start_desc(chan); 466 spin_unlock_irqrestore(&ch->vc.lock, flags); 467 } 468 469 static size_t moxart_dma_desc_size(struct moxart_desc *d, 470 unsigned int completed_sgs) 471 { 472 unsigned int i; 473 size_t size; 474 475 for (size = i = completed_sgs; i < d->sglen; i++) 476 size += d->sg[i].len; 477 478 return size; 479 } 480 481 static size_t moxart_dma_desc_size_in_flight(struct moxart_chan *ch) 482 { 483 size_t size; 484 unsigned int completed_cycles, cycles; 485 486 size = moxart_dma_desc_size(ch->desc, ch->sgidx); 487 cycles = readl(ch->base + REG_OFF_CYCLES); 488 completed_cycles = (ch->desc->dma_cycles - cycles); 489 size -= completed_cycles << es_bytes[ch->desc->es]; 490 491 dev_dbg(chan2dev(&ch->vc.chan), "%s: size=%zu\n", __func__, size); 492 493 return size; 494 } 495 496 static enum dma_status moxart_tx_status(struct dma_chan *chan, 497 dma_cookie_t cookie, 498 struct dma_tx_state *txstate) 499 { 500 struct moxart_chan *ch = to_moxart_dma_chan(chan); 501 struct virt_dma_desc *vd; 502 struct moxart_desc *d; 503 enum dma_status ret; 504 unsigned long flags; 505 506 /* 507 * dma_cookie_status() assigns initial residue value. 508 */ 509 ret = dma_cookie_status(chan, cookie, txstate); 510 511 spin_lock_irqsave(&ch->vc.lock, flags); 512 vd = vchan_find_desc(&ch->vc, cookie); 513 if (vd) { 514 d = to_moxart_dma_desc(&vd->tx); 515 txstate->residue = moxart_dma_desc_size(d, 0); 516 } else if (ch->desc && ch->desc->vd.tx.cookie == cookie) { 517 txstate->residue = moxart_dma_desc_size_in_flight(ch); 518 } 519 spin_unlock_irqrestore(&ch->vc.lock, flags); 520 521 if (ch->error) 522 return DMA_ERROR; 523 524 return ret; 525 } 526 527 static void moxart_dma_init(struct dma_device *dma, struct device *dev) 528 { 529 dma->device_prep_slave_sg = moxart_prep_slave_sg; 530 dma->device_alloc_chan_resources = moxart_alloc_chan_resources; 531 dma->device_free_chan_resources = moxart_free_chan_resources; 532 dma->device_issue_pending = moxart_issue_pending; 533 dma->device_tx_status = moxart_tx_status; 534 dma->device_control = moxart_control; 535 dma->dev = dev; 536 537 INIT_LIST_HEAD(&dma->channels); 538 } 539 540 static irqreturn_t moxart_dma_interrupt(int irq, void *devid) 541 { 542 struct moxart_dmadev *mc = devid; 543 struct moxart_chan *ch = &mc->slave_chans[0]; 544 unsigned int i; 545 unsigned long flags; 546 u32 ctrl; 547 548 dev_dbg(chan2dev(&ch->vc.chan), "%s\n", __func__); 549 550 for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, ch++) { 551 if (!ch->allocated) 552 continue; 553 554 ctrl = readl(ch->base + REG_OFF_CTRL); 555 556 dev_dbg(chan2dev(&ch->vc.chan), "%s: ch=%p ch->base=%p ctrl=%x\n", 557 __func__, ch, ch->base, ctrl); 558 559 if (ctrl & APB_DMA_FIN_INT_STS) { 560 ctrl &= ~APB_DMA_FIN_INT_STS; 561 if (ch->desc) { 562 spin_lock_irqsave(&ch->vc.lock, flags); 563 if (++ch->sgidx < ch->desc->sglen) { 564 moxart_dma_start_sg(ch, ch->sgidx); 565 } else { 566 vchan_cookie_complete(&ch->desc->vd); 567 moxart_dma_start_desc(&ch->vc.chan); 568 } 569 spin_unlock_irqrestore(&ch->vc.lock, flags); 570 } 571 } 572 573 if (ctrl & APB_DMA_ERR_INT_STS) { 574 ctrl &= ~APB_DMA_ERR_INT_STS; 575 ch->error = 1; 576 } 577 578 writel(ctrl, ch->base + REG_OFF_CTRL); 579 } 580 581 return IRQ_HANDLED; 582 } 583 584 static int moxart_probe(struct platform_device *pdev) 585 { 586 struct device *dev = &pdev->dev; 587 struct device_node *node = dev->of_node; 588 struct resource *res; 589 static void __iomem *dma_base_addr; 590 int ret, i; 591 unsigned int irq; 592 struct moxart_chan *ch; 593 struct moxart_dmadev *mdc; 594 595 mdc = devm_kzalloc(dev, sizeof(*mdc), GFP_KERNEL); 596 if (!mdc) { 597 dev_err(dev, "can't allocate DMA container\n"); 598 return -ENOMEM; 599 } 600 601 irq = irq_of_parse_and_map(node, 0); 602 if (irq == NO_IRQ) { 603 dev_err(dev, "no IRQ resource\n"); 604 return -EINVAL; 605 } 606 607 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 608 dma_base_addr = devm_ioremap_resource(dev, res); 609 if (IS_ERR(dma_base_addr)) 610 return PTR_ERR(dma_base_addr); 611 612 dma_cap_zero(mdc->dma_slave.cap_mask); 613 dma_cap_set(DMA_SLAVE, mdc->dma_slave.cap_mask); 614 dma_cap_set(DMA_PRIVATE, mdc->dma_slave.cap_mask); 615 616 moxart_dma_init(&mdc->dma_slave, dev); 617 618 ch = &mdc->slave_chans[0]; 619 for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, ch++) { 620 ch->ch_num = i; 621 ch->base = dma_base_addr + i * REG_OFF_CHAN_SIZE; 622 ch->allocated = 0; 623 624 ch->vc.desc_free = moxart_dma_desc_free; 625 vchan_init(&ch->vc, &mdc->dma_slave); 626 627 dev_dbg(dev, "%s: chs[%d]: ch->ch_num=%u ch->base=%p\n", 628 __func__, i, ch->ch_num, ch->base); 629 } 630 631 platform_set_drvdata(pdev, mdc); 632 633 ret = devm_request_irq(dev, irq, moxart_dma_interrupt, 0, 634 "moxart-dma-engine", mdc); 635 if (ret) { 636 dev_err(dev, "devm_request_irq failed\n"); 637 return ret; 638 } 639 640 ret = dma_async_device_register(&mdc->dma_slave); 641 if (ret) { 642 dev_err(dev, "dma_async_device_register failed\n"); 643 return ret; 644 } 645 646 ret = of_dma_controller_register(node, moxart_of_xlate, mdc); 647 if (ret) { 648 dev_err(dev, "of_dma_controller_register failed\n"); 649 dma_async_device_unregister(&mdc->dma_slave); 650 return ret; 651 } 652 653 dev_dbg(dev, "%s: IRQ=%u\n", __func__, irq); 654 655 return 0; 656 } 657 658 static int moxart_remove(struct platform_device *pdev) 659 { 660 struct moxart_dmadev *m = platform_get_drvdata(pdev); 661 662 dma_async_device_unregister(&m->dma_slave); 663 664 if (pdev->dev.of_node) 665 of_dma_controller_free(pdev->dev.of_node); 666 667 return 0; 668 } 669 670 static const struct of_device_id moxart_dma_match[] = { 671 { .compatible = "moxa,moxart-dma" }, 672 { } 673 }; 674 675 static struct platform_driver moxart_driver = { 676 .probe = moxart_probe, 677 .remove = moxart_remove, 678 .driver = { 679 .name = "moxart-dma-engine", 680 .of_match_table = moxart_dma_match, 681 }, 682 }; 683 684 static int moxart_init(void) 685 { 686 return platform_driver_register(&moxart_driver); 687 } 688 subsys_initcall(moxart_init); 689 690 static void __exit moxart_exit(void) 691 { 692 platform_driver_unregister(&moxart_driver); 693 } 694 module_exit(moxart_exit); 695 696 MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>"); 697 MODULE_DESCRIPTION("MOXART DMA engine driver"); 698 MODULE_LICENSE("GPL v2"); 699