1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Renesas USB DMA Controller Driver 4 * 5 * Copyright (C) 2015 Renesas Electronics Corporation 6 * 7 * based on rcar-dmac.c 8 * Copyright (C) 2014 Renesas Electronics Inc. 9 * Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com> 10 */ 11 12 #include <linux/delay.h> 13 #include <linux/dma-mapping.h> 14 #include <linux/dmaengine.h> 15 #include <linux/interrupt.h> 16 #include <linux/list.h> 17 #include <linux/module.h> 18 #include <linux/of.h> 19 #include <linux/of_dma.h> 20 #include <linux/of_platform.h> 21 #include <linux/platform_device.h> 22 #include <linux/pm_runtime.h> 23 #include <linux/slab.h> 24 #include <linux/spinlock.h> 25 26 #include "../dmaengine.h" 27 #include "../virt-dma.h" 28 29 /* 30 * struct usb_dmac_sg - Descriptor for a hardware transfer 31 * @mem_addr: memory address 32 * @size: transfer size in bytes 33 */ 34 struct usb_dmac_sg { 35 dma_addr_t mem_addr; 36 u32 size; 37 }; 38 39 /* 40 * struct usb_dmac_desc - USB DMA Transfer Descriptor 41 * @vd: base virtual channel DMA transaction descriptor 42 * @direction: direction of the DMA transfer 43 * @sg_allocated_len: length of allocated sg 44 * @sg_len: length of sg 45 * @sg_index: index of sg 46 * @residue: residue after the DMAC completed a transfer 47 * @node: node for desc_got and desc_freed 48 * @done_cookie: cookie after the DMAC completed a transfer 49 * @sg: information for the transfer 50 */ 51 struct usb_dmac_desc { 52 struct virt_dma_desc vd; 53 enum dma_transfer_direction direction; 54 unsigned int sg_allocated_len; 55 unsigned int sg_len; 56 unsigned int sg_index; 57 u32 residue; 58 struct list_head node; 59 dma_cookie_t done_cookie; 60 struct usb_dmac_sg sg[]; 61 }; 62 63 #define to_usb_dmac_desc(vd) container_of(vd, struct usb_dmac_desc, vd) 64 65 /* 66 * struct usb_dmac_chan - USB DMA Controller Channel 67 * @vc: base virtual DMA channel object 68 * @iomem: channel I/O memory base 69 * @index: index of this channel in the controller 70 * @irq: irq number of this channel 71 * @desc: the current descriptor 72 * @descs_allocated: number of descriptors allocated 73 * @desc_got: got descriptors 74 * @desc_freed: freed descriptors after the DMAC completed a transfer 75 */ 76 struct usb_dmac_chan { 77 struct virt_dma_chan vc; 78 void __iomem *iomem; 79 unsigned int index; 80 int irq; 81 struct usb_dmac_desc *desc; 82 int descs_allocated; 83 struct list_head desc_got; 84 struct list_head desc_freed; 85 }; 86 87 #define to_usb_dmac_chan(c) container_of(c, struct usb_dmac_chan, vc.chan) 88 89 /* 90 * struct usb_dmac - USB DMA Controller 91 * @engine: base DMA engine object 92 * @dev: the hardware device 93 * @iomem: remapped I/O memory base 94 * @n_channels: number of available channels 95 * @channels: array of DMAC channels 96 */ 97 struct usb_dmac { 98 struct dma_device engine; 99 struct device *dev; 100 void __iomem *iomem; 101 102 unsigned int n_channels; 103 struct usb_dmac_chan *channels; 104 }; 105 106 #define to_usb_dmac(d) container_of(d, struct usb_dmac, engine) 107 108 /* ----------------------------------------------------------------------------- 109 * Registers 110 */ 111 112 #define USB_DMAC_CHAN_OFFSET(i) (0x20 + 0x20 * (i)) 113 114 #define USB_DMASWR 0x0008 115 #define USB_DMASWR_SWR (1 << 0) 116 #define USB_DMAOR 0x0060 117 #define USB_DMAOR_AE (1 << 1) 118 #define USB_DMAOR_DME (1 << 0) 119 120 #define USB_DMASAR 0x0000 121 #define USB_DMADAR 0x0004 122 #define USB_DMATCR 0x0008 123 #define USB_DMATCR_MASK 0x00ffffff 124 #define USB_DMACHCR 0x0014 125 #define USB_DMACHCR_FTE (1 << 24) 126 #define USB_DMACHCR_NULLE (1 << 16) 127 #define USB_DMACHCR_NULL (1 << 12) 128 #define USB_DMACHCR_TS_8B ((0 << 7) | (0 << 6)) 129 #define USB_DMACHCR_TS_16B ((0 << 7) | (1 << 6)) 130 #define USB_DMACHCR_TS_32B ((1 << 7) | (0 << 6)) 131 #define USB_DMACHCR_IE (1 << 5) 132 #define USB_DMACHCR_SP (1 << 2) 133 #define USB_DMACHCR_TE (1 << 1) 134 #define USB_DMACHCR_DE (1 << 0) 135 #define USB_DMATEND 0x0018 136 137 /* Hardcode the xfer_shift to 5 (32bytes) */ 138 #define USB_DMAC_XFER_SHIFT 5 139 #define USB_DMAC_XFER_SIZE (1 << USB_DMAC_XFER_SHIFT) 140 #define USB_DMAC_CHCR_TS USB_DMACHCR_TS_32B 141 #define USB_DMAC_SLAVE_BUSWIDTH DMA_SLAVE_BUSWIDTH_32_BYTES 142 143 /* for descriptors */ 144 #define USB_DMAC_INITIAL_NR_DESC 16 145 #define USB_DMAC_INITIAL_NR_SG 8 146 147 /* ----------------------------------------------------------------------------- 148 * Device access 149 */ 150 151 static void usb_dmac_write(struct usb_dmac *dmac, u32 reg, u32 data) 152 { 153 writel(data, dmac->iomem + reg); 154 } 155 156 static u32 usb_dmac_read(struct usb_dmac *dmac, u32 reg) 157 { 158 return readl(dmac->iomem + reg); 159 } 160 161 static u32 usb_dmac_chan_read(struct usb_dmac_chan *chan, u32 reg) 162 { 163 return readl(chan->iomem + reg); 164 } 165 166 static void usb_dmac_chan_write(struct usb_dmac_chan *chan, u32 reg, u32 data) 167 { 168 writel(data, chan->iomem + reg); 169 } 170 171 /* ----------------------------------------------------------------------------- 172 * Initialization and configuration 173 */ 174 175 static bool usb_dmac_chan_is_busy(struct usb_dmac_chan *chan) 176 { 177 u32 chcr = usb_dmac_chan_read(chan, USB_DMACHCR); 178 179 return (chcr & (USB_DMACHCR_DE | USB_DMACHCR_TE)) == USB_DMACHCR_DE; 180 } 181 182 static u32 usb_dmac_calc_tend(u32 size) 183 { 184 /* 185 * Please refer to the Figure "Example of Final Transaction Valid 186 * Data Transfer Enable (EDTEN) Setting" in the data sheet. 187 */ 188 return 0xffffffff << (32 - (size % USB_DMAC_XFER_SIZE ? : 189 USB_DMAC_XFER_SIZE)); 190 } 191 192 /* This function is already held by vc.lock */ 193 static void usb_dmac_chan_start_sg(struct usb_dmac_chan *chan, 194 unsigned int index) 195 { 196 struct usb_dmac_desc *desc = chan->desc; 197 struct usb_dmac_sg *sg = desc->sg + index; 198 dma_addr_t src_addr = 0, dst_addr = 0; 199 200 WARN_ON_ONCE(usb_dmac_chan_is_busy(chan)); 201 202 if (desc->direction == DMA_DEV_TO_MEM) 203 dst_addr = sg->mem_addr; 204 else 205 src_addr = sg->mem_addr; 206 207 dev_dbg(chan->vc.chan.device->dev, 208 "chan%u: queue sg %p: %u@%pad -> %pad\n", 209 chan->index, sg, sg->size, &src_addr, &dst_addr); 210 211 usb_dmac_chan_write(chan, USB_DMASAR, src_addr & 0xffffffff); 212 usb_dmac_chan_write(chan, USB_DMADAR, dst_addr & 0xffffffff); 213 usb_dmac_chan_write(chan, USB_DMATCR, 214 DIV_ROUND_UP(sg->size, USB_DMAC_XFER_SIZE)); 215 usb_dmac_chan_write(chan, USB_DMATEND, usb_dmac_calc_tend(sg->size)); 216 217 usb_dmac_chan_write(chan, USB_DMACHCR, USB_DMAC_CHCR_TS | 218 USB_DMACHCR_NULLE | USB_DMACHCR_IE | USB_DMACHCR_DE); 219 } 220 221 /* This function is already held by vc.lock */ 222 static void usb_dmac_chan_start_desc(struct usb_dmac_chan *chan) 223 { 224 struct virt_dma_desc *vd; 225 226 vd = vchan_next_desc(&chan->vc); 227 if (!vd) { 228 chan->desc = NULL; 229 return; 230 } 231 232 /* 233 * Remove this request from vc->desc_issued. Otherwise, this driver 234 * will get the previous value from vchan_next_desc() after a transfer 235 * was completed. 236 */ 237 list_del(&vd->node); 238 239 chan->desc = to_usb_dmac_desc(vd); 240 chan->desc->sg_index = 0; 241 usb_dmac_chan_start_sg(chan, 0); 242 } 243 244 static int usb_dmac_init(struct usb_dmac *dmac) 245 { 246 u16 dmaor; 247 248 /* Clear all channels and enable the DMAC globally. */ 249 usb_dmac_write(dmac, USB_DMAOR, USB_DMAOR_DME); 250 251 dmaor = usb_dmac_read(dmac, USB_DMAOR); 252 if ((dmaor & (USB_DMAOR_AE | USB_DMAOR_DME)) != USB_DMAOR_DME) { 253 dev_warn(dmac->dev, "DMAOR initialization failed.\n"); 254 return -EIO; 255 } 256 257 return 0; 258 } 259 260 /* ----------------------------------------------------------------------------- 261 * Descriptors allocation and free 262 */ 263 static int usb_dmac_desc_alloc(struct usb_dmac_chan *chan, unsigned int sg_len, 264 gfp_t gfp) 265 { 266 struct usb_dmac_desc *desc; 267 unsigned long flags; 268 269 desc = kzalloc(struct_size(desc, sg, sg_len), gfp); 270 if (!desc) 271 return -ENOMEM; 272 273 desc->sg_allocated_len = sg_len; 274 INIT_LIST_HEAD(&desc->node); 275 276 spin_lock_irqsave(&chan->vc.lock, flags); 277 list_add_tail(&desc->node, &chan->desc_freed); 278 spin_unlock_irqrestore(&chan->vc.lock, flags); 279 280 return 0; 281 } 282 283 static void usb_dmac_desc_free(struct usb_dmac_chan *chan) 284 { 285 struct usb_dmac_desc *desc, *_desc; 286 LIST_HEAD(list); 287 288 list_splice_init(&chan->desc_freed, &list); 289 list_splice_init(&chan->desc_got, &list); 290 291 list_for_each_entry_safe(desc, _desc, &list, node) { 292 list_del(&desc->node); 293 kfree(desc); 294 } 295 chan->descs_allocated = 0; 296 } 297 298 static struct usb_dmac_desc *usb_dmac_desc_get(struct usb_dmac_chan *chan, 299 unsigned int sg_len, gfp_t gfp) 300 { 301 struct usb_dmac_desc *desc = NULL; 302 unsigned long flags; 303 304 /* Get a freed descritpor */ 305 spin_lock_irqsave(&chan->vc.lock, flags); 306 list_for_each_entry(desc, &chan->desc_freed, node) { 307 if (sg_len <= desc->sg_allocated_len) { 308 list_move_tail(&desc->node, &chan->desc_got); 309 spin_unlock_irqrestore(&chan->vc.lock, flags); 310 return desc; 311 } 312 } 313 spin_unlock_irqrestore(&chan->vc.lock, flags); 314 315 /* Allocate a new descriptor */ 316 if (!usb_dmac_desc_alloc(chan, sg_len, gfp)) { 317 /* If allocated the desc, it was added to tail of the list */ 318 spin_lock_irqsave(&chan->vc.lock, flags); 319 desc = list_last_entry(&chan->desc_freed, struct usb_dmac_desc, 320 node); 321 list_move_tail(&desc->node, &chan->desc_got); 322 spin_unlock_irqrestore(&chan->vc.lock, flags); 323 return desc; 324 } 325 326 return NULL; 327 } 328 329 static void usb_dmac_desc_put(struct usb_dmac_chan *chan, 330 struct usb_dmac_desc *desc) 331 { 332 unsigned long flags; 333 334 spin_lock_irqsave(&chan->vc.lock, flags); 335 list_move_tail(&desc->node, &chan->desc_freed); 336 spin_unlock_irqrestore(&chan->vc.lock, flags); 337 } 338 339 /* ----------------------------------------------------------------------------- 340 * Stop and reset 341 */ 342 343 static void usb_dmac_soft_reset(struct usb_dmac_chan *uchan) 344 { 345 struct dma_chan *chan = &uchan->vc.chan; 346 struct usb_dmac *dmac = to_usb_dmac(chan->device); 347 int i; 348 349 /* Don't issue soft reset if any one of channels is busy */ 350 for (i = 0; i < dmac->n_channels; ++i) { 351 if (usb_dmac_chan_is_busy(uchan)) 352 return; 353 } 354 355 usb_dmac_write(dmac, USB_DMAOR, 0); 356 usb_dmac_write(dmac, USB_DMASWR, USB_DMASWR_SWR); 357 udelay(100); 358 usb_dmac_write(dmac, USB_DMASWR, 0); 359 usb_dmac_write(dmac, USB_DMAOR, 1); 360 } 361 362 static void usb_dmac_chan_halt(struct usb_dmac_chan *chan) 363 { 364 u32 chcr = usb_dmac_chan_read(chan, USB_DMACHCR); 365 366 chcr &= ~(USB_DMACHCR_IE | USB_DMACHCR_TE | USB_DMACHCR_DE); 367 usb_dmac_chan_write(chan, USB_DMACHCR, chcr); 368 369 usb_dmac_soft_reset(chan); 370 } 371 372 static void usb_dmac_stop(struct usb_dmac *dmac) 373 { 374 usb_dmac_write(dmac, USB_DMAOR, 0); 375 } 376 377 /* ----------------------------------------------------------------------------- 378 * DMA engine operations 379 */ 380 381 static int usb_dmac_alloc_chan_resources(struct dma_chan *chan) 382 { 383 struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan); 384 int ret; 385 386 while (uchan->descs_allocated < USB_DMAC_INITIAL_NR_DESC) { 387 ret = usb_dmac_desc_alloc(uchan, USB_DMAC_INITIAL_NR_SG, 388 GFP_KERNEL); 389 if (ret < 0) { 390 usb_dmac_desc_free(uchan); 391 return ret; 392 } 393 uchan->descs_allocated++; 394 } 395 396 return pm_runtime_get_sync(chan->device->dev); 397 } 398 399 static void usb_dmac_free_chan_resources(struct dma_chan *chan) 400 { 401 struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan); 402 unsigned long flags; 403 404 /* Protect against ISR */ 405 spin_lock_irqsave(&uchan->vc.lock, flags); 406 usb_dmac_chan_halt(uchan); 407 spin_unlock_irqrestore(&uchan->vc.lock, flags); 408 409 usb_dmac_desc_free(uchan); 410 vchan_free_chan_resources(&uchan->vc); 411 412 pm_runtime_put(chan->device->dev); 413 } 414 415 static struct dma_async_tx_descriptor * 416 usb_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, 417 unsigned int sg_len, enum dma_transfer_direction dir, 418 unsigned long dma_flags, void *context) 419 { 420 struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan); 421 struct usb_dmac_desc *desc; 422 struct scatterlist *sg; 423 int i; 424 425 if (!sg_len) { 426 dev_warn(chan->device->dev, 427 "%s: bad parameter: len=%d\n", __func__, sg_len); 428 return NULL; 429 } 430 431 desc = usb_dmac_desc_get(uchan, sg_len, GFP_NOWAIT); 432 if (!desc) 433 return NULL; 434 435 desc->direction = dir; 436 desc->sg_len = sg_len; 437 for_each_sg(sgl, sg, sg_len, i) { 438 desc->sg[i].mem_addr = sg_dma_address(sg); 439 desc->sg[i].size = sg_dma_len(sg); 440 } 441 442 return vchan_tx_prep(&uchan->vc, &desc->vd, dma_flags); 443 } 444 445 static int usb_dmac_chan_terminate_all(struct dma_chan *chan) 446 { 447 struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan); 448 struct usb_dmac_desc *desc, *_desc; 449 unsigned long flags; 450 LIST_HEAD(head); 451 LIST_HEAD(list); 452 453 spin_lock_irqsave(&uchan->vc.lock, flags); 454 usb_dmac_chan_halt(uchan); 455 vchan_get_all_descriptors(&uchan->vc, &head); 456 if (uchan->desc) 457 uchan->desc = NULL; 458 list_splice_init(&uchan->desc_got, &list); 459 list_for_each_entry_safe(desc, _desc, &list, node) 460 list_move_tail(&desc->node, &uchan->desc_freed); 461 spin_unlock_irqrestore(&uchan->vc.lock, flags); 462 vchan_dma_desc_free_list(&uchan->vc, &head); 463 464 return 0; 465 } 466 467 static unsigned int usb_dmac_get_current_residue(struct usb_dmac_chan *chan, 468 struct usb_dmac_desc *desc, 469 int sg_index) 470 { 471 struct usb_dmac_sg *sg = desc->sg + sg_index; 472 u32 mem_addr = sg->mem_addr & 0xffffffff; 473 unsigned int residue = sg->size; 474 475 /* 476 * We cannot use USB_DMATCR to calculate residue because USB_DMATCR 477 * has unsuited value to calculate. 478 */ 479 if (desc->direction == DMA_DEV_TO_MEM) 480 residue -= usb_dmac_chan_read(chan, USB_DMADAR) - mem_addr; 481 else 482 residue -= usb_dmac_chan_read(chan, USB_DMASAR) - mem_addr; 483 484 return residue; 485 } 486 487 static u32 usb_dmac_chan_get_residue_if_complete(struct usb_dmac_chan *chan, 488 dma_cookie_t cookie) 489 { 490 struct usb_dmac_desc *desc; 491 u32 residue = 0; 492 493 list_for_each_entry_reverse(desc, &chan->desc_freed, node) { 494 if (desc->done_cookie == cookie) { 495 residue = desc->residue; 496 break; 497 } 498 } 499 500 return residue; 501 } 502 503 static u32 usb_dmac_chan_get_residue(struct usb_dmac_chan *chan, 504 dma_cookie_t cookie) 505 { 506 u32 residue = 0; 507 struct virt_dma_desc *vd; 508 struct usb_dmac_desc *desc = chan->desc; 509 int i; 510 511 if (!desc) { 512 vd = vchan_find_desc(&chan->vc, cookie); 513 if (!vd) 514 return 0; 515 desc = to_usb_dmac_desc(vd); 516 } 517 518 /* Compute the size of all usb_dmac_sg still to be transferred */ 519 for (i = desc->sg_index + 1; i < desc->sg_len; i++) 520 residue += desc->sg[i].size; 521 522 /* Add the residue for the current sg */ 523 residue += usb_dmac_get_current_residue(chan, desc, desc->sg_index); 524 525 return residue; 526 } 527 528 static enum dma_status usb_dmac_tx_status(struct dma_chan *chan, 529 dma_cookie_t cookie, 530 struct dma_tx_state *txstate) 531 { 532 struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan); 533 enum dma_status status; 534 unsigned int residue = 0; 535 unsigned long flags; 536 537 status = dma_cookie_status(chan, cookie, txstate); 538 /* a client driver will get residue after DMA_COMPLETE */ 539 if (!txstate) 540 return status; 541 542 spin_lock_irqsave(&uchan->vc.lock, flags); 543 if (status == DMA_COMPLETE) 544 residue = usb_dmac_chan_get_residue_if_complete(uchan, cookie); 545 else 546 residue = usb_dmac_chan_get_residue(uchan, cookie); 547 spin_unlock_irqrestore(&uchan->vc.lock, flags); 548 549 dma_set_residue(txstate, residue); 550 551 return status; 552 } 553 554 static void usb_dmac_issue_pending(struct dma_chan *chan) 555 { 556 struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan); 557 unsigned long flags; 558 559 spin_lock_irqsave(&uchan->vc.lock, flags); 560 if (vchan_issue_pending(&uchan->vc) && !uchan->desc) 561 usb_dmac_chan_start_desc(uchan); 562 spin_unlock_irqrestore(&uchan->vc.lock, flags); 563 } 564 565 static void usb_dmac_virt_desc_free(struct virt_dma_desc *vd) 566 { 567 struct usb_dmac_desc *desc = to_usb_dmac_desc(vd); 568 struct usb_dmac_chan *chan = to_usb_dmac_chan(vd->tx.chan); 569 570 usb_dmac_desc_put(chan, desc); 571 } 572 573 /* ----------------------------------------------------------------------------- 574 * IRQ handling 575 */ 576 577 static void usb_dmac_isr_transfer_end(struct usb_dmac_chan *chan) 578 { 579 struct usb_dmac_desc *desc = chan->desc; 580 581 BUG_ON(!desc); 582 583 if (++desc->sg_index < desc->sg_len) { 584 usb_dmac_chan_start_sg(chan, desc->sg_index); 585 } else { 586 desc->residue = usb_dmac_get_current_residue(chan, desc, 587 desc->sg_index - 1); 588 desc->done_cookie = desc->vd.tx.cookie; 589 vchan_cookie_complete(&desc->vd); 590 591 /* Restart the next transfer if this driver has a next desc */ 592 usb_dmac_chan_start_desc(chan); 593 } 594 } 595 596 static irqreturn_t usb_dmac_isr_channel(int irq, void *dev) 597 { 598 struct usb_dmac_chan *chan = dev; 599 irqreturn_t ret = IRQ_NONE; 600 u32 mask = 0; 601 u32 chcr; 602 bool xfer_end = false; 603 604 spin_lock(&chan->vc.lock); 605 606 chcr = usb_dmac_chan_read(chan, USB_DMACHCR); 607 if (chcr & (USB_DMACHCR_TE | USB_DMACHCR_SP)) { 608 mask |= USB_DMACHCR_DE | USB_DMACHCR_TE | USB_DMACHCR_SP; 609 if (chcr & USB_DMACHCR_DE) 610 xfer_end = true; 611 ret |= IRQ_HANDLED; 612 } 613 if (chcr & USB_DMACHCR_NULL) { 614 /* An interruption of TE will happen after we set FTE */ 615 mask |= USB_DMACHCR_NULL; 616 chcr |= USB_DMACHCR_FTE; 617 ret |= IRQ_HANDLED; 618 } 619 if (mask) 620 usb_dmac_chan_write(chan, USB_DMACHCR, chcr & ~mask); 621 622 if (xfer_end) 623 usb_dmac_isr_transfer_end(chan); 624 625 spin_unlock(&chan->vc.lock); 626 627 return ret; 628 } 629 630 /* ----------------------------------------------------------------------------- 631 * OF xlate and channel filter 632 */ 633 634 static bool usb_dmac_chan_filter(struct dma_chan *chan, void *arg) 635 { 636 struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan); 637 struct of_phandle_args *dma_spec = arg; 638 639 /* USB-DMAC should be used with fixed usb controller's FIFO */ 640 if (uchan->index != dma_spec->args[0]) 641 return false; 642 643 return true; 644 } 645 646 static struct dma_chan *usb_dmac_of_xlate(struct of_phandle_args *dma_spec, 647 struct of_dma *ofdma) 648 { 649 struct dma_chan *chan; 650 dma_cap_mask_t mask; 651 652 if (dma_spec->args_count != 1) 653 return NULL; 654 655 /* Only slave DMA channels can be allocated via DT */ 656 dma_cap_zero(mask); 657 dma_cap_set(DMA_SLAVE, mask); 658 659 chan = __dma_request_channel(&mask, usb_dmac_chan_filter, dma_spec, 660 ofdma->of_node); 661 if (!chan) 662 return NULL; 663 664 return chan; 665 } 666 667 /* ----------------------------------------------------------------------------- 668 * Power management 669 */ 670 671 #ifdef CONFIG_PM 672 static int usb_dmac_runtime_suspend(struct device *dev) 673 { 674 struct usb_dmac *dmac = dev_get_drvdata(dev); 675 int i; 676 677 for (i = 0; i < dmac->n_channels; ++i) { 678 if (!dmac->channels[i].iomem) 679 break; 680 usb_dmac_chan_halt(&dmac->channels[i]); 681 } 682 683 return 0; 684 } 685 686 static int usb_dmac_runtime_resume(struct device *dev) 687 { 688 struct usb_dmac *dmac = dev_get_drvdata(dev); 689 690 return usb_dmac_init(dmac); 691 } 692 #endif /* CONFIG_PM */ 693 694 static const struct dev_pm_ops usb_dmac_pm = { 695 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 696 pm_runtime_force_resume) 697 SET_RUNTIME_PM_OPS(usb_dmac_runtime_suspend, usb_dmac_runtime_resume, 698 NULL) 699 }; 700 701 /* ----------------------------------------------------------------------------- 702 * Probe and remove 703 */ 704 705 static int usb_dmac_chan_probe(struct usb_dmac *dmac, 706 struct usb_dmac_chan *uchan, 707 unsigned int index) 708 { 709 struct platform_device *pdev = to_platform_device(dmac->dev); 710 char pdev_irqname[5]; 711 char *irqname; 712 int ret; 713 714 uchan->index = index; 715 uchan->iomem = dmac->iomem + USB_DMAC_CHAN_OFFSET(index); 716 717 /* Request the channel interrupt. */ 718 sprintf(pdev_irqname, "ch%u", index); 719 uchan->irq = platform_get_irq_byname(pdev, pdev_irqname); 720 if (uchan->irq < 0) 721 return -ENODEV; 722 723 irqname = devm_kasprintf(dmac->dev, GFP_KERNEL, "%s:%u", 724 dev_name(dmac->dev), index); 725 if (!irqname) 726 return -ENOMEM; 727 728 ret = devm_request_irq(dmac->dev, uchan->irq, usb_dmac_isr_channel, 729 IRQF_SHARED, irqname, uchan); 730 if (ret) { 731 dev_err(dmac->dev, "failed to request IRQ %u (%d)\n", 732 uchan->irq, ret); 733 return ret; 734 } 735 736 uchan->vc.desc_free = usb_dmac_virt_desc_free; 737 vchan_init(&uchan->vc, &dmac->engine); 738 INIT_LIST_HEAD(&uchan->desc_freed); 739 INIT_LIST_HEAD(&uchan->desc_got); 740 741 return 0; 742 } 743 744 static int usb_dmac_parse_of(struct device *dev, struct usb_dmac *dmac) 745 { 746 struct device_node *np = dev->of_node; 747 int ret; 748 749 ret = of_property_read_u32(np, "dma-channels", &dmac->n_channels); 750 if (ret < 0) { 751 dev_err(dev, "unable to read dma-channels property\n"); 752 return ret; 753 } 754 755 if (dmac->n_channels <= 0 || dmac->n_channels >= 100) { 756 dev_err(dev, "invalid number of channels %u\n", 757 dmac->n_channels); 758 return -EINVAL; 759 } 760 761 return 0; 762 } 763 764 static int usb_dmac_probe(struct platform_device *pdev) 765 { 766 const enum dma_slave_buswidth widths = USB_DMAC_SLAVE_BUSWIDTH; 767 struct dma_device *engine; 768 struct usb_dmac *dmac; 769 struct resource *mem; 770 unsigned int i; 771 int ret; 772 773 dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL); 774 if (!dmac) 775 return -ENOMEM; 776 777 dmac->dev = &pdev->dev; 778 platform_set_drvdata(pdev, dmac); 779 780 ret = usb_dmac_parse_of(&pdev->dev, dmac); 781 if (ret < 0) 782 return ret; 783 784 dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels, 785 sizeof(*dmac->channels), GFP_KERNEL); 786 if (!dmac->channels) 787 return -ENOMEM; 788 789 /* Request resources. */ 790 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 791 dmac->iomem = devm_ioremap_resource(&pdev->dev, mem); 792 if (IS_ERR(dmac->iomem)) 793 return PTR_ERR(dmac->iomem); 794 795 /* Enable runtime PM and initialize the device. */ 796 pm_runtime_enable(&pdev->dev); 797 ret = pm_runtime_get_sync(&pdev->dev); 798 if (ret < 0) { 799 dev_err(&pdev->dev, "runtime PM get sync failed (%d)\n", ret); 800 goto error_pm; 801 } 802 803 ret = usb_dmac_init(dmac); 804 805 if (ret) { 806 dev_err(&pdev->dev, "failed to reset device\n"); 807 goto error; 808 } 809 810 /* Initialize the channels. */ 811 INIT_LIST_HEAD(&dmac->engine.channels); 812 813 for (i = 0; i < dmac->n_channels; ++i) { 814 ret = usb_dmac_chan_probe(dmac, &dmac->channels[i], i); 815 if (ret < 0) 816 goto error; 817 } 818 819 /* Register the DMAC as a DMA provider for DT. */ 820 ret = of_dma_controller_register(pdev->dev.of_node, usb_dmac_of_xlate, 821 NULL); 822 if (ret < 0) 823 goto error; 824 825 /* 826 * Register the DMA engine device. 827 * 828 * Default transfer size of 32 bytes requires 32-byte alignment. 829 */ 830 engine = &dmac->engine; 831 dma_cap_set(DMA_SLAVE, engine->cap_mask); 832 833 engine->dev = &pdev->dev; 834 835 engine->src_addr_widths = widths; 836 engine->dst_addr_widths = widths; 837 engine->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM); 838 engine->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; 839 840 engine->device_alloc_chan_resources = usb_dmac_alloc_chan_resources; 841 engine->device_free_chan_resources = usb_dmac_free_chan_resources; 842 engine->device_prep_slave_sg = usb_dmac_prep_slave_sg; 843 engine->device_terminate_all = usb_dmac_chan_terminate_all; 844 engine->device_tx_status = usb_dmac_tx_status; 845 engine->device_issue_pending = usb_dmac_issue_pending; 846 847 ret = dma_async_device_register(engine); 848 if (ret < 0) 849 goto error; 850 851 pm_runtime_put(&pdev->dev); 852 return 0; 853 854 error: 855 of_dma_controller_free(pdev->dev.of_node); 856 pm_runtime_put(&pdev->dev); 857 error_pm: 858 pm_runtime_disable(&pdev->dev); 859 return ret; 860 } 861 862 static void usb_dmac_chan_remove(struct usb_dmac *dmac, 863 struct usb_dmac_chan *uchan) 864 { 865 usb_dmac_chan_halt(uchan); 866 devm_free_irq(dmac->dev, uchan->irq, uchan); 867 } 868 869 static int usb_dmac_remove(struct platform_device *pdev) 870 { 871 struct usb_dmac *dmac = platform_get_drvdata(pdev); 872 int i; 873 874 for (i = 0; i < dmac->n_channels; ++i) 875 usb_dmac_chan_remove(dmac, &dmac->channels[i]); 876 of_dma_controller_free(pdev->dev.of_node); 877 dma_async_device_unregister(&dmac->engine); 878 879 pm_runtime_disable(&pdev->dev); 880 881 return 0; 882 } 883 884 static void usb_dmac_shutdown(struct platform_device *pdev) 885 { 886 struct usb_dmac *dmac = platform_get_drvdata(pdev); 887 888 usb_dmac_stop(dmac); 889 } 890 891 static const struct of_device_id usb_dmac_of_ids[] = { 892 { .compatible = "renesas,usb-dmac", }, 893 { /* Sentinel */ } 894 }; 895 MODULE_DEVICE_TABLE(of, usb_dmac_of_ids); 896 897 static struct platform_driver usb_dmac_driver = { 898 .driver = { 899 .pm = &usb_dmac_pm, 900 .name = "usb-dmac", 901 .of_match_table = usb_dmac_of_ids, 902 }, 903 .probe = usb_dmac_probe, 904 .remove = usb_dmac_remove, 905 .shutdown = usb_dmac_shutdown, 906 }; 907 908 module_platform_driver(usb_dmac_driver); 909 910 MODULE_DESCRIPTION("Renesas USB DMA Controller Driver"); 911 MODULE_AUTHOR("Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>"); 912 MODULE_LICENSE("GPL v2"); 913