1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Core driver for the Synopsys DesignWare DMA Controller 4 * 5 * Copyright (C) 2007-2008 Atmel Corporation 6 * Copyright (C) 2010-2011 ST Microelectronics 7 * Copyright (C) 2013 Intel Corporation 8 */ 9 10 #include <linux/bitops.h> 11 #include <linux/delay.h> 12 #include <linux/dmaengine.h> 13 #include <linux/dma-mapping.h> 14 #include <linux/dmapool.h> 15 #include <linux/err.h> 16 #include <linux/init.h> 17 #include <linux/interrupt.h> 18 #include <linux/io.h> 19 #include <linux/mm.h> 20 #include <linux/module.h> 21 #include <linux/slab.h> 22 #include <linux/pm_runtime.h> 23 24 #include "../dmaengine.h" 25 #include "internal.h" 26 27 /* 28 * This supports the Synopsys "DesignWare AHB Central DMA Controller", 29 * (DW_ahb_dmac) which is used with various AMBA 2.0 systems (not all 30 * of which use ARM any more). See the "Databook" from Synopsys for 31 * information beyond what licensees probably provide. 32 * 33 * The driver has been tested with the Atmel AT32AP7000, which does not 34 * support descriptor writeback. 35 */ 36 37 /* The set of bus widths supported by the DMA controller */ 38 #define DW_DMA_BUSWIDTHS \ 39 BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \ 40 BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \ 41 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \ 42 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) 43 44 /*----------------------------------------------------------------------*/ 45 46 static struct device *chan2dev(struct dma_chan *chan) 47 { 48 return &chan->dev->device; 49 } 50 51 static struct dw_desc *dwc_first_active(struct dw_dma_chan *dwc) 52 { 53 return to_dw_desc(dwc->active_list.next); 54 } 55 56 static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx) 57 { 58 struct dw_desc *desc = txd_to_dw_desc(tx); 59 struct dw_dma_chan *dwc = to_dw_dma_chan(tx->chan); 60 dma_cookie_t cookie; 61 unsigned long flags; 62 63 spin_lock_irqsave(&dwc->lock, flags); 64 cookie = dma_cookie_assign(tx); 65 66 /* 67 * REVISIT: We should attempt to chain as many descriptors as 68 * possible, perhaps even appending to those already submitted 69 * for DMA. But this is hard to do in a race-free manner. 70 */ 71 72 list_add_tail(&desc->desc_node, &dwc->queue); 73 spin_unlock_irqrestore(&dwc->lock, flags); 74 dev_vdbg(chan2dev(tx->chan), "%s: queued %u\n", 75 __func__, desc->txd.cookie); 76 77 return cookie; 78 } 79 80 static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc) 81 { 82 struct dw_dma *dw = to_dw_dma(dwc->chan.device); 83 struct dw_desc *desc; 84 dma_addr_t phys; 85 86 desc = dma_pool_zalloc(dw->desc_pool, GFP_ATOMIC, &phys); 87 if (!desc) 88 return NULL; 89 90 dwc->descs_allocated++; 91 INIT_LIST_HEAD(&desc->tx_list); 92 dma_async_tx_descriptor_init(&desc->txd, &dwc->chan); 93 desc->txd.tx_submit = dwc_tx_submit; 94 desc->txd.flags = DMA_CTRL_ACK; 95 desc->txd.phys = phys; 96 return desc; 97 } 98 99 static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc) 100 { 101 struct dw_dma *dw = to_dw_dma(dwc->chan.device); 102 struct dw_desc *child, *_next; 103 104 if (unlikely(!desc)) 105 return; 106 107 list_for_each_entry_safe(child, _next, &desc->tx_list, desc_node) { 108 list_del(&child->desc_node); 109 dma_pool_free(dw->desc_pool, child, child->txd.phys); 110 dwc->descs_allocated--; 111 } 112 113 dma_pool_free(dw->desc_pool, desc, desc->txd.phys); 114 dwc->descs_allocated--; 115 } 116 117 static void dwc_initialize(struct dw_dma_chan *dwc) 118 { 119 struct dw_dma *dw = to_dw_dma(dwc->chan.device); 120 121 dw->initialize_chan(dwc); 122 123 /* Enable interrupts */ 124 channel_set_bit(dw, MASK.XFER, dwc->mask); 125 channel_set_bit(dw, MASK.ERROR, dwc->mask); 126 } 127 128 /*----------------------------------------------------------------------*/ 129 130 static inline void dwc_dump_chan_regs(struct dw_dma_chan *dwc) 131 { 132 dev_err(chan2dev(&dwc->chan), 133 " SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n", 134 channel_readl(dwc, SAR), 135 channel_readl(dwc, DAR), 136 channel_readl(dwc, LLP), 137 channel_readl(dwc, CTL_HI), 138 channel_readl(dwc, CTL_LO)); 139 } 140 141 static inline void dwc_chan_disable(struct dw_dma *dw, struct dw_dma_chan *dwc) 142 { 143 channel_clear_bit(dw, CH_EN, dwc->mask); 144 while (dma_readl(dw, CH_EN) & dwc->mask) 145 cpu_relax(); 146 } 147 148 /*----------------------------------------------------------------------*/ 149 150 /* Perform single block transfer */ 151 static inline void dwc_do_single_block(struct dw_dma_chan *dwc, 152 struct dw_desc *desc) 153 { 154 struct dw_dma *dw = to_dw_dma(dwc->chan.device); 155 u32 ctllo; 156 157 /* 158 * Software emulation of LLP mode relies on interrupts to continue 159 * multi block transfer. 160 */ 161 ctllo = lli_read(desc, ctllo) | DWC_CTLL_INT_EN; 162 163 channel_writel(dwc, SAR, lli_read(desc, sar)); 164 channel_writel(dwc, DAR, lli_read(desc, dar)); 165 channel_writel(dwc, CTL_LO, ctllo); 166 channel_writel(dwc, CTL_HI, lli_read(desc, ctlhi)); 167 channel_set_bit(dw, CH_EN, dwc->mask); 168 169 /* Move pointer to next descriptor */ 170 dwc->tx_node_active = dwc->tx_node_active->next; 171 } 172 173 /* Called with dwc->lock held and bh disabled */ 174 static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first) 175 { 176 struct dw_dma *dw = to_dw_dma(dwc->chan.device); 177 u8 lms = DWC_LLP_LMS(dwc->dws.m_master); 178 unsigned long was_soft_llp; 179 180 /* ASSERT: channel is idle */ 181 if (dma_readl(dw, CH_EN) & dwc->mask) { 182 dev_err(chan2dev(&dwc->chan), 183 "%s: BUG: Attempted to start non-idle channel\n", 184 __func__); 185 dwc_dump_chan_regs(dwc); 186 187 /* The tasklet will hopefully advance the queue... */ 188 return; 189 } 190 191 if (dwc->nollp) { 192 was_soft_llp = test_and_set_bit(DW_DMA_IS_SOFT_LLP, 193 &dwc->flags); 194 if (was_soft_llp) { 195 dev_err(chan2dev(&dwc->chan), 196 "BUG: Attempted to start new LLP transfer inside ongoing one\n"); 197 return; 198 } 199 200 dwc_initialize(dwc); 201 202 first->residue = first->total_len; 203 dwc->tx_node_active = &first->tx_list; 204 205 /* Submit first block */ 206 dwc_do_single_block(dwc, first); 207 208 return; 209 } 210 211 dwc_initialize(dwc); 212 213 channel_writel(dwc, LLP, first->txd.phys | lms); 214 channel_writel(dwc, CTL_LO, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN); 215 channel_writel(dwc, CTL_HI, 0); 216 channel_set_bit(dw, CH_EN, dwc->mask); 217 } 218 219 static void dwc_dostart_first_queued(struct dw_dma_chan *dwc) 220 { 221 struct dw_desc *desc; 222 223 if (list_empty(&dwc->queue)) 224 return; 225 226 list_move(dwc->queue.next, &dwc->active_list); 227 desc = dwc_first_active(dwc); 228 dev_vdbg(chan2dev(&dwc->chan), "%s: started %u\n", __func__, desc->txd.cookie); 229 dwc_dostart(dwc, desc); 230 } 231 232 /*----------------------------------------------------------------------*/ 233 234 static void 235 dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc, 236 bool callback_required) 237 { 238 struct dma_async_tx_descriptor *txd = &desc->txd; 239 struct dw_desc *child; 240 unsigned long flags; 241 struct dmaengine_desc_callback cb; 242 243 dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie); 244 245 spin_lock_irqsave(&dwc->lock, flags); 246 dma_cookie_complete(txd); 247 if (callback_required) 248 dmaengine_desc_get_callback(txd, &cb); 249 else 250 memset(&cb, 0, sizeof(cb)); 251 252 /* async_tx_ack */ 253 list_for_each_entry(child, &desc->tx_list, desc_node) 254 async_tx_ack(&child->txd); 255 async_tx_ack(&desc->txd); 256 dwc_desc_put(dwc, desc); 257 spin_unlock_irqrestore(&dwc->lock, flags); 258 259 dmaengine_desc_callback_invoke(&cb, NULL); 260 } 261 262 static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc) 263 { 264 struct dw_desc *desc, *_desc; 265 LIST_HEAD(list); 266 unsigned long flags; 267 268 spin_lock_irqsave(&dwc->lock, flags); 269 if (dma_readl(dw, CH_EN) & dwc->mask) { 270 dev_err(chan2dev(&dwc->chan), 271 "BUG: XFER bit set, but channel not idle!\n"); 272 273 /* Try to continue after resetting the channel... */ 274 dwc_chan_disable(dw, dwc); 275 } 276 277 /* 278 * Submit queued descriptors ASAP, i.e. before we go through 279 * the completed ones. 280 */ 281 list_splice_init(&dwc->active_list, &list); 282 dwc_dostart_first_queued(dwc); 283 284 spin_unlock_irqrestore(&dwc->lock, flags); 285 286 list_for_each_entry_safe(desc, _desc, &list, desc_node) 287 dwc_descriptor_complete(dwc, desc, true); 288 } 289 290 /* Returns how many bytes were already received from source */ 291 static inline u32 dwc_get_sent(struct dw_dma_chan *dwc) 292 { 293 struct dw_dma *dw = to_dw_dma(dwc->chan.device); 294 u32 ctlhi = channel_readl(dwc, CTL_HI); 295 u32 ctllo = channel_readl(dwc, CTL_LO); 296 297 return dw->block2bytes(dwc, ctlhi, ctllo >> 4 & 7); 298 } 299 300 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc) 301 { 302 dma_addr_t llp; 303 struct dw_desc *desc, *_desc; 304 struct dw_desc *child; 305 u32 status_xfer; 306 unsigned long flags; 307 308 spin_lock_irqsave(&dwc->lock, flags); 309 llp = channel_readl(dwc, LLP); 310 status_xfer = dma_readl(dw, RAW.XFER); 311 312 if (status_xfer & dwc->mask) { 313 /* Everything we've submitted is done */ 314 dma_writel(dw, CLEAR.XFER, dwc->mask); 315 316 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) { 317 struct list_head *head, *active = dwc->tx_node_active; 318 319 /* 320 * We are inside first active descriptor. 321 * Otherwise something is really wrong. 322 */ 323 desc = dwc_first_active(dwc); 324 325 head = &desc->tx_list; 326 if (active != head) { 327 /* Update residue to reflect last sent descriptor */ 328 if (active == head->next) 329 desc->residue -= desc->len; 330 else 331 desc->residue -= to_dw_desc(active->prev)->len; 332 333 child = to_dw_desc(active); 334 335 /* Submit next block */ 336 dwc_do_single_block(dwc, child); 337 338 spin_unlock_irqrestore(&dwc->lock, flags); 339 return; 340 } 341 342 /* We are done here */ 343 clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags); 344 } 345 346 spin_unlock_irqrestore(&dwc->lock, flags); 347 348 dwc_complete_all(dw, dwc); 349 return; 350 } 351 352 if (list_empty(&dwc->active_list)) { 353 spin_unlock_irqrestore(&dwc->lock, flags); 354 return; 355 } 356 357 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) { 358 dev_vdbg(chan2dev(&dwc->chan), "%s: soft LLP mode\n", __func__); 359 spin_unlock_irqrestore(&dwc->lock, flags); 360 return; 361 } 362 363 dev_vdbg(chan2dev(&dwc->chan), "%s: llp=%pad\n", __func__, &llp); 364 365 list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) { 366 /* Initial residue value */ 367 desc->residue = desc->total_len; 368 369 /* Check first descriptors addr */ 370 if (desc->txd.phys == DWC_LLP_LOC(llp)) { 371 spin_unlock_irqrestore(&dwc->lock, flags); 372 return; 373 } 374 375 /* Check first descriptors llp */ 376 if (lli_read(desc, llp) == llp) { 377 /* This one is currently in progress */ 378 desc->residue -= dwc_get_sent(dwc); 379 spin_unlock_irqrestore(&dwc->lock, flags); 380 return; 381 } 382 383 desc->residue -= desc->len; 384 list_for_each_entry(child, &desc->tx_list, desc_node) { 385 if (lli_read(child, llp) == llp) { 386 /* Currently in progress */ 387 desc->residue -= dwc_get_sent(dwc); 388 spin_unlock_irqrestore(&dwc->lock, flags); 389 return; 390 } 391 desc->residue -= child->len; 392 } 393 394 /* 395 * No descriptors so far seem to be in progress, i.e. 396 * this one must be done. 397 */ 398 spin_unlock_irqrestore(&dwc->lock, flags); 399 dwc_descriptor_complete(dwc, desc, true); 400 spin_lock_irqsave(&dwc->lock, flags); 401 } 402 403 dev_err(chan2dev(&dwc->chan), 404 "BUG: All descriptors done, but channel not idle!\n"); 405 406 /* Try to continue after resetting the channel... */ 407 dwc_chan_disable(dw, dwc); 408 409 dwc_dostart_first_queued(dwc); 410 spin_unlock_irqrestore(&dwc->lock, flags); 411 } 412 413 static inline void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_desc *desc) 414 { 415 dev_crit(chan2dev(&dwc->chan), " desc: s0x%x d0x%x l0x%x c0x%x:%x\n", 416 lli_read(desc, sar), 417 lli_read(desc, dar), 418 lli_read(desc, llp), 419 lli_read(desc, ctlhi), 420 lli_read(desc, ctllo)); 421 } 422 423 static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc) 424 { 425 struct dw_desc *bad_desc; 426 struct dw_desc *child; 427 unsigned long flags; 428 429 dwc_scan_descriptors(dw, dwc); 430 431 spin_lock_irqsave(&dwc->lock, flags); 432 433 /* 434 * The descriptor currently at the head of the active list is 435 * borked. Since we don't have any way to report errors, we'll 436 * just have to scream loudly and try to carry on. 437 */ 438 bad_desc = dwc_first_active(dwc); 439 list_del_init(&bad_desc->desc_node); 440 list_move(dwc->queue.next, dwc->active_list.prev); 441 442 /* Clear the error flag and try to restart the controller */ 443 dma_writel(dw, CLEAR.ERROR, dwc->mask); 444 if (!list_empty(&dwc->active_list)) 445 dwc_dostart(dwc, dwc_first_active(dwc)); 446 447 /* 448 * WARN may seem harsh, but since this only happens 449 * when someone submits a bad physical address in a 450 * descriptor, we should consider ourselves lucky that the 451 * controller flagged an error instead of scribbling over 452 * random memory locations. 453 */ 454 dev_WARN(chan2dev(&dwc->chan), "Bad descriptor submitted for DMA!\n" 455 " cookie: %d\n", bad_desc->txd.cookie); 456 dwc_dump_lli(dwc, bad_desc); 457 list_for_each_entry(child, &bad_desc->tx_list, desc_node) 458 dwc_dump_lli(dwc, child); 459 460 spin_unlock_irqrestore(&dwc->lock, flags); 461 462 /* Pretend the descriptor completed successfully */ 463 dwc_descriptor_complete(dwc, bad_desc, true); 464 } 465 466 static void dw_dma_tasklet(struct tasklet_struct *t) 467 { 468 struct dw_dma *dw = from_tasklet(dw, t, tasklet); 469 struct dw_dma_chan *dwc; 470 u32 status_xfer; 471 u32 status_err; 472 unsigned int i; 473 474 status_xfer = dma_readl(dw, RAW.XFER); 475 status_err = dma_readl(dw, RAW.ERROR); 476 477 dev_vdbg(dw->dma.dev, "%s: status_err=%x\n", __func__, status_err); 478 479 for (i = 0; i < dw->dma.chancnt; i++) { 480 dwc = &dw->chan[i]; 481 if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) 482 dev_vdbg(dw->dma.dev, "Cyclic xfer is not implemented\n"); 483 else if (status_err & (1 << i)) 484 dwc_handle_error(dw, dwc); 485 else if (status_xfer & (1 << i)) 486 dwc_scan_descriptors(dw, dwc); 487 } 488 489 /* Re-enable interrupts */ 490 channel_set_bit(dw, MASK.XFER, dw->all_chan_mask); 491 channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask); 492 } 493 494 static irqreturn_t dw_dma_interrupt(int irq, void *dev_id) 495 { 496 struct dw_dma *dw = dev_id; 497 u32 status; 498 499 /* Check if we have any interrupt from the DMAC which is not in use */ 500 if (!dw->in_use) 501 return IRQ_NONE; 502 503 status = dma_readl(dw, STATUS_INT); 504 dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__, status); 505 506 /* Check if we have any interrupt from the DMAC */ 507 if (!status) 508 return IRQ_NONE; 509 510 /* 511 * Just disable the interrupts. We'll turn them back on in the 512 * softirq handler. 513 */ 514 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask); 515 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask); 516 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask); 517 518 status = dma_readl(dw, STATUS_INT); 519 if (status) { 520 dev_err(dw->dma.dev, 521 "BUG: Unexpected interrupts pending: 0x%x\n", 522 status); 523 524 /* Try to recover */ 525 channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1); 526 channel_clear_bit(dw, MASK.BLOCK, (1 << 8) - 1); 527 channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1); 528 channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1); 529 channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1); 530 } 531 532 tasklet_schedule(&dw->tasklet); 533 534 return IRQ_HANDLED; 535 } 536 537 /*----------------------------------------------------------------------*/ 538 539 static struct dma_async_tx_descriptor * 540 dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, 541 size_t len, unsigned long flags) 542 { 543 struct dw_dma_chan *dwc = to_dw_dma_chan(chan); 544 struct dw_dma *dw = to_dw_dma(chan->device); 545 struct dw_desc *desc; 546 struct dw_desc *first; 547 struct dw_desc *prev; 548 size_t xfer_count; 549 size_t offset; 550 u8 m_master = dwc->dws.m_master; 551 unsigned int src_width; 552 unsigned int dst_width; 553 unsigned int data_width = dw->pdata->data_width[m_master]; 554 u32 ctllo, ctlhi; 555 u8 lms = DWC_LLP_LMS(m_master); 556 557 dev_vdbg(chan2dev(chan), 558 "%s: d%pad s%pad l0x%zx f0x%lx\n", __func__, 559 &dest, &src, len, flags); 560 561 if (unlikely(!len)) { 562 dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__); 563 return NULL; 564 } 565 566 dwc->direction = DMA_MEM_TO_MEM; 567 568 src_width = dst_width = __ffs(data_width | src | dest | len); 569 570 ctllo = dw->prepare_ctllo(dwc) 571 | DWC_CTLL_DST_WIDTH(dst_width) 572 | DWC_CTLL_SRC_WIDTH(src_width) 573 | DWC_CTLL_DST_INC 574 | DWC_CTLL_SRC_INC 575 | DWC_CTLL_FC_M2M; 576 prev = first = NULL; 577 578 for (offset = 0; offset < len; offset += xfer_count) { 579 desc = dwc_desc_get(dwc); 580 if (!desc) 581 goto err_desc_get; 582 583 ctlhi = dw->bytes2block(dwc, len - offset, src_width, &xfer_count); 584 585 lli_write(desc, sar, src + offset); 586 lli_write(desc, dar, dest + offset); 587 lli_write(desc, ctllo, ctllo); 588 lli_write(desc, ctlhi, ctlhi); 589 desc->len = xfer_count; 590 591 if (!first) { 592 first = desc; 593 } else { 594 lli_write(prev, llp, desc->txd.phys | lms); 595 list_add_tail(&desc->desc_node, &first->tx_list); 596 } 597 prev = desc; 598 } 599 600 if (flags & DMA_PREP_INTERRUPT) 601 /* Trigger interrupt after last block */ 602 lli_set(prev, ctllo, DWC_CTLL_INT_EN); 603 604 prev->lli.llp = 0; 605 lli_clear(prev, ctllo, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN); 606 first->txd.flags = flags; 607 first->total_len = len; 608 609 return &first->txd; 610 611 err_desc_get: 612 dwc_desc_put(dwc, first); 613 return NULL; 614 } 615 616 static struct dma_async_tx_descriptor * 617 dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, 618 unsigned int sg_len, enum dma_transfer_direction direction, 619 unsigned long flags, void *context) 620 { 621 struct dw_dma_chan *dwc = to_dw_dma_chan(chan); 622 struct dw_dma *dw = to_dw_dma(chan->device); 623 struct dma_slave_config *sconfig = &dwc->dma_sconfig; 624 struct dw_desc *prev; 625 struct dw_desc *first; 626 u32 ctllo, ctlhi; 627 u8 m_master = dwc->dws.m_master; 628 u8 lms = DWC_LLP_LMS(m_master); 629 dma_addr_t reg; 630 unsigned int reg_width; 631 unsigned int mem_width; 632 unsigned int data_width = dw->pdata->data_width[m_master]; 633 unsigned int i; 634 struct scatterlist *sg; 635 size_t total_len = 0; 636 637 dev_vdbg(chan2dev(chan), "%s\n", __func__); 638 639 if (unlikely(!is_slave_direction(direction) || !sg_len)) 640 return NULL; 641 642 dwc->direction = direction; 643 644 prev = first = NULL; 645 646 switch (direction) { 647 case DMA_MEM_TO_DEV: 648 reg_width = __ffs(sconfig->dst_addr_width); 649 reg = sconfig->dst_addr; 650 ctllo = dw->prepare_ctllo(dwc) 651 | DWC_CTLL_DST_WIDTH(reg_width) 652 | DWC_CTLL_DST_FIX 653 | DWC_CTLL_SRC_INC; 654 655 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_M2P) : 656 DWC_CTLL_FC(DW_DMA_FC_D_M2P); 657 658 for_each_sg(sgl, sg, sg_len, i) { 659 struct dw_desc *desc; 660 u32 len, mem; 661 size_t dlen; 662 663 mem = sg_dma_address(sg); 664 len = sg_dma_len(sg); 665 666 mem_width = __ffs(data_width | mem | len); 667 668 slave_sg_todev_fill_desc: 669 desc = dwc_desc_get(dwc); 670 if (!desc) 671 goto err_desc_get; 672 673 ctlhi = dw->bytes2block(dwc, len, mem_width, &dlen); 674 675 lli_write(desc, sar, mem); 676 lli_write(desc, dar, reg); 677 lli_write(desc, ctlhi, ctlhi); 678 lli_write(desc, ctllo, ctllo | DWC_CTLL_SRC_WIDTH(mem_width)); 679 desc->len = dlen; 680 681 if (!first) { 682 first = desc; 683 } else { 684 lli_write(prev, llp, desc->txd.phys | lms); 685 list_add_tail(&desc->desc_node, &first->tx_list); 686 } 687 prev = desc; 688 689 mem += dlen; 690 len -= dlen; 691 total_len += dlen; 692 693 if (len) 694 goto slave_sg_todev_fill_desc; 695 } 696 break; 697 case DMA_DEV_TO_MEM: 698 reg_width = __ffs(sconfig->src_addr_width); 699 reg = sconfig->src_addr; 700 ctllo = dw->prepare_ctllo(dwc) 701 | DWC_CTLL_SRC_WIDTH(reg_width) 702 | DWC_CTLL_DST_INC 703 | DWC_CTLL_SRC_FIX; 704 705 ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_P2M) : 706 DWC_CTLL_FC(DW_DMA_FC_D_P2M); 707 708 for_each_sg(sgl, sg, sg_len, i) { 709 struct dw_desc *desc; 710 u32 len, mem; 711 size_t dlen; 712 713 mem = sg_dma_address(sg); 714 len = sg_dma_len(sg); 715 716 slave_sg_fromdev_fill_desc: 717 desc = dwc_desc_get(dwc); 718 if (!desc) 719 goto err_desc_get; 720 721 ctlhi = dw->bytes2block(dwc, len, reg_width, &dlen); 722 723 lli_write(desc, sar, reg); 724 lli_write(desc, dar, mem); 725 lli_write(desc, ctlhi, ctlhi); 726 mem_width = __ffs(data_width | mem); 727 lli_write(desc, ctllo, ctllo | DWC_CTLL_DST_WIDTH(mem_width)); 728 desc->len = dlen; 729 730 if (!first) { 731 first = desc; 732 } else { 733 lli_write(prev, llp, desc->txd.phys | lms); 734 list_add_tail(&desc->desc_node, &first->tx_list); 735 } 736 prev = desc; 737 738 mem += dlen; 739 len -= dlen; 740 total_len += dlen; 741 742 if (len) 743 goto slave_sg_fromdev_fill_desc; 744 } 745 break; 746 default: 747 return NULL; 748 } 749 750 if (flags & DMA_PREP_INTERRUPT) 751 /* Trigger interrupt after last block */ 752 lli_set(prev, ctllo, DWC_CTLL_INT_EN); 753 754 prev->lli.llp = 0; 755 lli_clear(prev, ctllo, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN); 756 first->total_len = total_len; 757 758 return &first->txd; 759 760 err_desc_get: 761 dev_err(chan2dev(chan), 762 "not enough descriptors available. Direction %d\n", direction); 763 dwc_desc_put(dwc, first); 764 return NULL; 765 } 766 767 bool dw_dma_filter(struct dma_chan *chan, void *param) 768 { 769 struct dw_dma_chan *dwc = to_dw_dma_chan(chan); 770 struct dw_dma_slave *dws = param; 771 772 if (dws->dma_dev != chan->device->dev) 773 return false; 774 775 /* permit channels in accordance with the channels mask */ 776 if (dws->channels && !(dws->channels & dwc->mask)) 777 return false; 778 779 /* We have to copy data since dws can be temporary storage */ 780 memcpy(&dwc->dws, dws, sizeof(struct dw_dma_slave)); 781 782 return true; 783 } 784 EXPORT_SYMBOL_GPL(dw_dma_filter); 785 786 static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig) 787 { 788 struct dw_dma_chan *dwc = to_dw_dma_chan(chan); 789 struct dw_dma *dw = to_dw_dma(chan->device); 790 791 memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig)); 792 793 dwc->dma_sconfig.src_maxburst = 794 clamp(dwc->dma_sconfig.src_maxburst, 0U, dwc->max_burst); 795 dwc->dma_sconfig.dst_maxburst = 796 clamp(dwc->dma_sconfig.dst_maxburst, 0U, dwc->max_burst); 797 798 dw->encode_maxburst(dwc, &dwc->dma_sconfig.src_maxburst); 799 dw->encode_maxburst(dwc, &dwc->dma_sconfig.dst_maxburst); 800 801 return 0; 802 } 803 804 static void dwc_chan_pause(struct dw_dma_chan *dwc, bool drain) 805 { 806 struct dw_dma *dw = to_dw_dma(dwc->chan.device); 807 unsigned int count = 20; /* timeout iterations */ 808 809 dw->suspend_chan(dwc, drain); 810 811 while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY) && count--) 812 udelay(2); 813 814 set_bit(DW_DMA_IS_PAUSED, &dwc->flags); 815 } 816 817 static int dwc_pause(struct dma_chan *chan) 818 { 819 struct dw_dma_chan *dwc = to_dw_dma_chan(chan); 820 unsigned long flags; 821 822 spin_lock_irqsave(&dwc->lock, flags); 823 dwc_chan_pause(dwc, false); 824 spin_unlock_irqrestore(&dwc->lock, flags); 825 826 return 0; 827 } 828 829 static inline void dwc_chan_resume(struct dw_dma_chan *dwc, bool drain) 830 { 831 struct dw_dma *dw = to_dw_dma(dwc->chan.device); 832 833 dw->resume_chan(dwc, drain); 834 835 clear_bit(DW_DMA_IS_PAUSED, &dwc->flags); 836 } 837 838 static int dwc_resume(struct dma_chan *chan) 839 { 840 struct dw_dma_chan *dwc = to_dw_dma_chan(chan); 841 unsigned long flags; 842 843 spin_lock_irqsave(&dwc->lock, flags); 844 845 if (test_bit(DW_DMA_IS_PAUSED, &dwc->flags)) 846 dwc_chan_resume(dwc, false); 847 848 spin_unlock_irqrestore(&dwc->lock, flags); 849 850 return 0; 851 } 852 853 static int dwc_terminate_all(struct dma_chan *chan) 854 { 855 struct dw_dma_chan *dwc = to_dw_dma_chan(chan); 856 struct dw_dma *dw = to_dw_dma(chan->device); 857 struct dw_desc *desc, *_desc; 858 unsigned long flags; 859 LIST_HEAD(list); 860 861 spin_lock_irqsave(&dwc->lock, flags); 862 863 clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags); 864 865 dwc_chan_pause(dwc, true); 866 867 dwc_chan_disable(dw, dwc); 868 869 dwc_chan_resume(dwc, true); 870 871 /* active_list entries will end up before queued entries */ 872 list_splice_init(&dwc->queue, &list); 873 list_splice_init(&dwc->active_list, &list); 874 875 spin_unlock_irqrestore(&dwc->lock, flags); 876 877 /* Flush all pending and queued descriptors */ 878 list_for_each_entry_safe(desc, _desc, &list, desc_node) 879 dwc_descriptor_complete(dwc, desc, false); 880 881 return 0; 882 } 883 884 static struct dw_desc *dwc_find_desc(struct dw_dma_chan *dwc, dma_cookie_t c) 885 { 886 struct dw_desc *desc; 887 888 list_for_each_entry(desc, &dwc->active_list, desc_node) 889 if (desc->txd.cookie == c) 890 return desc; 891 892 return NULL; 893 } 894 895 static u32 dwc_get_residue(struct dw_dma_chan *dwc, dma_cookie_t cookie) 896 { 897 struct dw_desc *desc; 898 unsigned long flags; 899 u32 residue; 900 901 spin_lock_irqsave(&dwc->lock, flags); 902 903 desc = dwc_find_desc(dwc, cookie); 904 if (desc) { 905 if (desc == dwc_first_active(dwc)) { 906 residue = desc->residue; 907 if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags) && residue) 908 residue -= dwc_get_sent(dwc); 909 } else { 910 residue = desc->total_len; 911 } 912 } else { 913 residue = 0; 914 } 915 916 spin_unlock_irqrestore(&dwc->lock, flags); 917 return residue; 918 } 919 920 static enum dma_status 921 dwc_tx_status(struct dma_chan *chan, 922 dma_cookie_t cookie, 923 struct dma_tx_state *txstate) 924 { 925 struct dw_dma_chan *dwc = to_dw_dma_chan(chan); 926 enum dma_status ret; 927 928 ret = dma_cookie_status(chan, cookie, txstate); 929 if (ret == DMA_COMPLETE) 930 return ret; 931 932 dwc_scan_descriptors(to_dw_dma(chan->device), dwc); 933 934 ret = dma_cookie_status(chan, cookie, txstate); 935 if (ret == DMA_COMPLETE) 936 return ret; 937 938 dma_set_residue(txstate, dwc_get_residue(dwc, cookie)); 939 940 if (test_bit(DW_DMA_IS_PAUSED, &dwc->flags) && ret == DMA_IN_PROGRESS) 941 return DMA_PAUSED; 942 943 return ret; 944 } 945 946 static void dwc_issue_pending(struct dma_chan *chan) 947 { 948 struct dw_dma_chan *dwc = to_dw_dma_chan(chan); 949 unsigned long flags; 950 951 spin_lock_irqsave(&dwc->lock, flags); 952 if (list_empty(&dwc->active_list)) 953 dwc_dostart_first_queued(dwc); 954 spin_unlock_irqrestore(&dwc->lock, flags); 955 } 956 957 /*----------------------------------------------------------------------*/ 958 959 void do_dw_dma_off(struct dw_dma *dw) 960 { 961 dma_writel(dw, CFG, 0); 962 963 channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask); 964 channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask); 965 channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask); 966 channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask); 967 channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask); 968 969 while (dma_readl(dw, CFG) & DW_CFG_DMA_EN) 970 cpu_relax(); 971 } 972 973 void do_dw_dma_on(struct dw_dma *dw) 974 { 975 dma_writel(dw, CFG, DW_CFG_DMA_EN); 976 } 977 978 static int dwc_alloc_chan_resources(struct dma_chan *chan) 979 { 980 struct dw_dma_chan *dwc = to_dw_dma_chan(chan); 981 struct dw_dma *dw = to_dw_dma(chan->device); 982 983 dev_vdbg(chan2dev(chan), "%s\n", __func__); 984 985 /* ASSERT: channel is idle */ 986 if (dma_readl(dw, CH_EN) & dwc->mask) { 987 dev_dbg(chan2dev(chan), "DMA channel not idle?\n"); 988 return -EIO; 989 } 990 991 dma_cookie_init(chan); 992 993 /* 994 * NOTE: some controllers may have additional features that we 995 * need to initialize here, like "scatter-gather" (which 996 * doesn't mean what you think it means), and status writeback. 997 */ 998 999 /* 1000 * We need controller-specific data to set up slave transfers. 1001 */ 1002 if (chan->private && !dw_dma_filter(chan, chan->private)) { 1003 dev_warn(chan2dev(chan), "Wrong controller-specific data\n"); 1004 return -EINVAL; 1005 } 1006 1007 /* Enable controller here if needed */ 1008 if (!dw->in_use) 1009 do_dw_dma_on(dw); 1010 dw->in_use |= dwc->mask; 1011 1012 return 0; 1013 } 1014 1015 static void dwc_free_chan_resources(struct dma_chan *chan) 1016 { 1017 struct dw_dma_chan *dwc = to_dw_dma_chan(chan); 1018 struct dw_dma *dw = to_dw_dma(chan->device); 1019 unsigned long flags; 1020 1021 dev_dbg(chan2dev(chan), "%s: descs allocated=%u\n", __func__, 1022 dwc->descs_allocated); 1023 1024 /* ASSERT: channel is idle */ 1025 BUG_ON(!list_empty(&dwc->active_list)); 1026 BUG_ON(!list_empty(&dwc->queue)); 1027 BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask); 1028 1029 spin_lock_irqsave(&dwc->lock, flags); 1030 1031 /* Clear custom channel configuration */ 1032 memset(&dwc->dws, 0, sizeof(struct dw_dma_slave)); 1033 1034 /* Disable interrupts */ 1035 channel_clear_bit(dw, MASK.XFER, dwc->mask); 1036 channel_clear_bit(dw, MASK.BLOCK, dwc->mask); 1037 channel_clear_bit(dw, MASK.ERROR, dwc->mask); 1038 1039 spin_unlock_irqrestore(&dwc->lock, flags); 1040 1041 /* Disable controller in case it was a last user */ 1042 dw->in_use &= ~dwc->mask; 1043 if (!dw->in_use) 1044 do_dw_dma_off(dw); 1045 1046 dev_vdbg(chan2dev(chan), "%s: done\n", __func__); 1047 } 1048 1049 static void dwc_caps(struct dma_chan *chan, struct dma_slave_caps *caps) 1050 { 1051 struct dw_dma_chan *dwc = to_dw_dma_chan(chan); 1052 1053 caps->max_burst = dwc->max_burst; 1054 1055 /* 1056 * It might be crucial for some devices to have the hardware 1057 * accelerated multi-block transfers supported, aka LLPs in DW DMAC 1058 * notation. So if LLPs are supported then max_sg_burst is set to 1059 * zero which means unlimited number of SG entries can be handled in a 1060 * single DMA transaction, otherwise it's just one SG entry. 1061 */ 1062 if (dwc->nollp) 1063 caps->max_sg_burst = 1; 1064 else 1065 caps->max_sg_burst = 0; 1066 } 1067 1068 int do_dma_probe(struct dw_dma_chip *chip) 1069 { 1070 struct dw_dma *dw = chip->dw; 1071 struct dw_dma_platform_data *pdata; 1072 bool autocfg = false; 1073 unsigned int dw_params; 1074 unsigned int i; 1075 int err; 1076 1077 dw->pdata = devm_kzalloc(chip->dev, sizeof(*dw->pdata), GFP_KERNEL); 1078 if (!dw->pdata) 1079 return -ENOMEM; 1080 1081 dw->regs = chip->regs; 1082 1083 pm_runtime_get_sync(chip->dev); 1084 1085 if (!chip->pdata) { 1086 dw_params = dma_readl(dw, DW_PARAMS); 1087 dev_dbg(chip->dev, "DW_PARAMS: 0x%08x\n", dw_params); 1088 1089 autocfg = dw_params >> DW_PARAMS_EN & 1; 1090 if (!autocfg) { 1091 err = -EINVAL; 1092 goto err_pdata; 1093 } 1094 1095 /* Reassign the platform data pointer */ 1096 pdata = dw->pdata; 1097 1098 /* Get hardware configuration parameters */ 1099 pdata->nr_channels = (dw_params >> DW_PARAMS_NR_CHAN & 7) + 1; 1100 pdata->nr_masters = (dw_params >> DW_PARAMS_NR_MASTER & 3) + 1; 1101 for (i = 0; i < pdata->nr_masters; i++) { 1102 pdata->data_width[i] = 1103 4 << (dw_params >> DW_PARAMS_DATA_WIDTH(i) & 3); 1104 } 1105 pdata->block_size = dma_readl(dw, MAX_BLK_SIZE); 1106 1107 /* Fill platform data with the default values */ 1108 pdata->chan_allocation_order = CHAN_ALLOCATION_ASCENDING; 1109 pdata->chan_priority = CHAN_PRIORITY_ASCENDING; 1110 } else if (chip->pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS) { 1111 err = -EINVAL; 1112 goto err_pdata; 1113 } else { 1114 memcpy(dw->pdata, chip->pdata, sizeof(*dw->pdata)); 1115 1116 /* Reassign the platform data pointer */ 1117 pdata = dw->pdata; 1118 } 1119 1120 dw->chan = devm_kcalloc(chip->dev, pdata->nr_channels, sizeof(*dw->chan), 1121 GFP_KERNEL); 1122 if (!dw->chan) { 1123 err = -ENOMEM; 1124 goto err_pdata; 1125 } 1126 1127 /* Calculate all channel mask before DMA setup */ 1128 dw->all_chan_mask = (1 << pdata->nr_channels) - 1; 1129 1130 /* Force dma off, just in case */ 1131 dw->disable(dw); 1132 1133 /* Device and instance ID for IRQ and DMA pool */ 1134 dw->set_device_name(dw, chip->id); 1135 1136 /* Create a pool of consistent memory blocks for hardware descriptors */ 1137 dw->desc_pool = dmam_pool_create(dw->name, chip->dev, 1138 sizeof(struct dw_desc), 4, 0); 1139 if (!dw->desc_pool) { 1140 dev_err(chip->dev, "No memory for descriptors dma pool\n"); 1141 err = -ENOMEM; 1142 goto err_pdata; 1143 } 1144 1145 tasklet_setup(&dw->tasklet, dw_dma_tasklet); 1146 1147 err = request_irq(chip->irq, dw_dma_interrupt, IRQF_SHARED, 1148 dw->name, dw); 1149 if (err) 1150 goto err_pdata; 1151 1152 INIT_LIST_HEAD(&dw->dma.channels); 1153 for (i = 0; i < pdata->nr_channels; i++) { 1154 struct dw_dma_chan *dwc = &dw->chan[i]; 1155 1156 dwc->chan.device = &dw->dma; 1157 dma_cookie_init(&dwc->chan); 1158 if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING) 1159 list_add_tail(&dwc->chan.device_node, 1160 &dw->dma.channels); 1161 else 1162 list_add(&dwc->chan.device_node, &dw->dma.channels); 1163 1164 /* 7 is highest priority & 0 is lowest. */ 1165 if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING) 1166 dwc->priority = pdata->nr_channels - i - 1; 1167 else 1168 dwc->priority = i; 1169 1170 dwc->ch_regs = &__dw_regs(dw)->CHAN[i]; 1171 spin_lock_init(&dwc->lock); 1172 dwc->mask = 1 << i; 1173 1174 INIT_LIST_HEAD(&dwc->active_list); 1175 INIT_LIST_HEAD(&dwc->queue); 1176 1177 channel_clear_bit(dw, CH_EN, dwc->mask); 1178 1179 dwc->direction = DMA_TRANS_NONE; 1180 1181 /* Hardware configuration */ 1182 if (autocfg) { 1183 unsigned int r = DW_DMA_MAX_NR_CHANNELS - i - 1; 1184 void __iomem *addr = &__dw_regs(dw)->DWC_PARAMS[r]; 1185 unsigned int dwc_params = readl(addr); 1186 1187 dev_dbg(chip->dev, "DWC_PARAMS[%d]: 0x%08x\n", i, 1188 dwc_params); 1189 1190 /* 1191 * Decode maximum block size for given channel. The 1192 * stored 4 bit value represents blocks from 0x00 for 3 1193 * up to 0x0a for 4095. 1194 */ 1195 dwc->block_size = 1196 (4 << ((pdata->block_size >> 4 * i) & 0xf)) - 1; 1197 1198 /* 1199 * According to the DW DMA databook the true scatter- 1200 * gether LLPs aren't available if either multi-block 1201 * config is disabled (CHx_MULTI_BLK_EN == 0) or the 1202 * LLP register is hard-coded to zeros 1203 * (CHx_HC_LLP == 1). 1204 */ 1205 dwc->nollp = 1206 (dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0 || 1207 (dwc_params >> DWC_PARAMS_HC_LLP & 0x1) == 1; 1208 dwc->max_burst = 1209 (0x4 << (dwc_params >> DWC_PARAMS_MSIZE & 0x7)); 1210 } else { 1211 dwc->block_size = pdata->block_size; 1212 dwc->nollp = !pdata->multi_block[i]; 1213 dwc->max_burst = pdata->max_burst[i] ?: DW_DMA_MAX_BURST; 1214 } 1215 } 1216 1217 /* Clear all interrupts on all channels. */ 1218 dma_writel(dw, CLEAR.XFER, dw->all_chan_mask); 1219 dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask); 1220 dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask); 1221 dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask); 1222 dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask); 1223 1224 /* Set capabilities */ 1225 dma_cap_set(DMA_SLAVE, dw->dma.cap_mask); 1226 dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask); 1227 dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask); 1228 1229 dw->dma.dev = chip->dev; 1230 dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources; 1231 dw->dma.device_free_chan_resources = dwc_free_chan_resources; 1232 1233 dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy; 1234 dw->dma.device_prep_slave_sg = dwc_prep_slave_sg; 1235 1236 dw->dma.device_caps = dwc_caps; 1237 dw->dma.device_config = dwc_config; 1238 dw->dma.device_pause = dwc_pause; 1239 dw->dma.device_resume = dwc_resume; 1240 dw->dma.device_terminate_all = dwc_terminate_all; 1241 1242 dw->dma.device_tx_status = dwc_tx_status; 1243 dw->dma.device_issue_pending = dwc_issue_pending; 1244 1245 /* DMA capabilities */ 1246 dw->dma.min_burst = DW_DMA_MIN_BURST; 1247 dw->dma.max_burst = DW_DMA_MAX_BURST; 1248 dw->dma.src_addr_widths = DW_DMA_BUSWIDTHS; 1249 dw->dma.dst_addr_widths = DW_DMA_BUSWIDTHS; 1250 dw->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) | 1251 BIT(DMA_MEM_TO_MEM); 1252 dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; 1253 1254 /* 1255 * For now there is no hardware with non uniform maximum block size 1256 * across all of the device channels, so we set the maximum segment 1257 * size as the block size found for the very first channel. 1258 */ 1259 dma_set_max_seg_size(dw->dma.dev, dw->chan[0].block_size); 1260 1261 err = dma_async_device_register(&dw->dma); 1262 if (err) 1263 goto err_dma_register; 1264 1265 dev_info(chip->dev, "DesignWare DMA Controller, %d channels\n", 1266 pdata->nr_channels); 1267 1268 pm_runtime_put_sync_suspend(chip->dev); 1269 1270 return 0; 1271 1272 err_dma_register: 1273 free_irq(chip->irq, dw); 1274 err_pdata: 1275 pm_runtime_put_sync_suspend(chip->dev); 1276 return err; 1277 } 1278 1279 int do_dma_remove(struct dw_dma_chip *chip) 1280 { 1281 struct dw_dma *dw = chip->dw; 1282 struct dw_dma_chan *dwc, *_dwc; 1283 1284 pm_runtime_get_sync(chip->dev); 1285 1286 do_dw_dma_off(dw); 1287 dma_async_device_unregister(&dw->dma); 1288 1289 free_irq(chip->irq, dw); 1290 tasklet_kill(&dw->tasklet); 1291 1292 list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels, 1293 chan.device_node) { 1294 list_del(&dwc->chan.device_node); 1295 channel_clear_bit(dw, CH_EN, dwc->mask); 1296 } 1297 1298 pm_runtime_put_sync_suspend(chip->dev); 1299 return 0; 1300 } 1301 1302 int do_dw_dma_disable(struct dw_dma_chip *chip) 1303 { 1304 struct dw_dma *dw = chip->dw; 1305 1306 dw->disable(dw); 1307 return 0; 1308 } 1309 EXPORT_SYMBOL_GPL(do_dw_dma_disable); 1310 1311 int do_dw_dma_enable(struct dw_dma_chip *chip) 1312 { 1313 struct dw_dma *dw = chip->dw; 1314 1315 dw->enable(dw); 1316 return 0; 1317 } 1318 EXPORT_SYMBOL_GPL(do_dw_dma_enable); 1319 1320 MODULE_LICENSE("GPL v2"); 1321 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller core driver"); 1322 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)"); 1323 MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>"); 1324