drivers/dma/sh/usb-dmac.c

   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");