drivers/dma/dma-axi-dmac.c

   1 /*
   2  * Driver for the Analog Devices AXI-DMAC core
   3  *
   4  * Copyright 2013-2015 Analog Devices Inc.
   5  *  Author: Lars-Peter Clausen <lars@metafoo.de>
   6  *
   7  * Licensed under the GPL-2.
   8  */
   9
  10 #include <linux/clk.h>
  11 #include <linux/device.h>
  12 #include <linux/dma-mapping.h>
  13 #include <linux/dmaengine.h>
  14 #include <linux/err.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/io.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/of.h>
  20 #include <linux/of_dma.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/slab.h>
  23
  24 #include <dt-bindings/dma/axi-dmac.h>
  25
  26 #include "dmaengine.h"
  27 #include "virt-dma.h"
  28
  29 /*
  30  * The AXI-DMAC is a soft IP core that is used in FPGA designs. The core has
  31  * various instantiation parameters which decided the exact feature set support
  32  * by the core.
  33  *
  34  * Each channel of the core has a source interface and a destination interface.
  35  * The number of channels and the type of the channel interfaces is selected at
  36  * configuration time. A interface can either be a connected to a central memory
  37  * interconnect, which allows access to system memory, or it can be connected to
  38  * a dedicated bus which is directly connected to a data port on a peripheral.
  39  * Given that those are configuration options of the core that are selected when
  40  * it is instantiated this means that they can not be changed by software at
  41  * runtime. By extension this means that each channel is uni-directional. It can
  42  * either be device to memory or memory to device, but not both. Also since the
  43  * device side is a dedicated data bus only connected to a single peripheral
  44  * there is no address than can or needs to be configured for the device side.
  45  */
  46
  47 #define AXI_DMAC_REG_IRQ_MASK           0x80
  48 #define AXI_DMAC_REG_IRQ_PENDING        0x84
  49 #define AXI_DMAC_REG_IRQ_SOURCE         0x88
  50
  51 #define AXI_DMAC_REG_CTRL               0x400
  52 #define AXI_DMAC_REG_TRANSFER_ID        0x404
  53 #define AXI_DMAC_REG_START_TRANSFER     0x408
  54 #define AXI_DMAC_REG_FLAGS              0x40c
  55 #define AXI_DMAC_REG_DEST_ADDRESS       0x410
  56 #define AXI_DMAC_REG_SRC_ADDRESS        0x414
  57 #define AXI_DMAC_REG_X_LENGTH           0x418
  58 #define AXI_DMAC_REG_Y_LENGTH           0x41c
  59 #define AXI_DMAC_REG_DEST_STRIDE        0x420
  60 #define AXI_DMAC_REG_SRC_STRIDE         0x424
  61 #define AXI_DMAC_REG_TRANSFER_DONE      0x428
  62 #define AXI_DMAC_REG_ACTIVE_TRANSFER_ID 0x42c
  63 #define AXI_DMAC_REG_STATUS             0x430
  64 #define AXI_DMAC_REG_CURRENT_SRC_ADDR   0x434
  65 #define AXI_DMAC_REG_CURRENT_DEST_ADDR  0x438
  66
  67 #define AXI_DMAC_CTRL_ENABLE            BIT(0)
  68 #define AXI_DMAC_CTRL_PAUSE             BIT(1)
  69
  70 #define AXI_DMAC_IRQ_SOT                BIT(0)
  71 #define AXI_DMAC_IRQ_EOT                BIT(1)
  72
  73 #define AXI_DMAC_FLAG_CYCLIC            BIT(0)
  74
  75 struct axi_dmac_sg {
  76         dma_addr_t src_addr;
  77         dma_addr_t dest_addr;
  78         unsigned int x_len;
  79         unsigned int y_len;
  80         unsigned int dest_stride;
  81         unsigned int src_stride;
  82         unsigned int id;
  83 };
  84
  85 struct axi_dmac_desc {
  86         struct virt_dma_desc vdesc;
  87         bool cyclic;
  88
  89         unsigned int num_submitted;
  90         unsigned int num_completed;
  91         unsigned int num_sgs;
  92         struct axi_dmac_sg sg[];
  93 };
  94
  95 struct axi_dmac_chan {
  96         struct virt_dma_chan vchan;
  97
  98         struct axi_dmac_desc *next_desc;
  99         struct list_head active_descs;
 100         enum dma_transfer_direction direction;
 101
 102         unsigned int src_width;
 103         unsigned int dest_width;
 104         unsigned int src_type;
 105         unsigned int dest_type;
 106
 107         unsigned int max_length;
 108         unsigned int align_mask;
 109
 110         bool hw_cyclic;
 111         bool hw_2d;
 112 };
 113
 114 struct axi_dmac {
 115         void __iomem *base;
 116         int irq;
 117
 118         struct clk *clk;
 119
 120         struct dma_device dma_dev;
 121         struct axi_dmac_chan chan;
 122
 123         struct device_dma_parameters dma_parms;
 124 };
 125
 126 static struct axi_dmac *chan_to_axi_dmac(struct axi_dmac_chan *chan)
 127 {
 128         return container_of(chan->vchan.chan.device, struct axi_dmac,
 129                 dma_dev);
 130 }
 131
 132 static struct axi_dmac_chan *to_axi_dmac_chan(struct dma_chan *c)
 133 {
 134         return container_of(c, struct axi_dmac_chan, vchan.chan);
 135 }
 136
 137 static struct axi_dmac_desc *to_axi_dmac_desc(struct virt_dma_desc *vdesc)
 138 {
 139         return container_of(vdesc, struct axi_dmac_desc, vdesc);
 140 }
 141
 142 static void axi_dmac_write(struct axi_dmac *axi_dmac, unsigned int reg,
 143         unsigned int val)
 144 {
 145         writel(val, axi_dmac->base + reg);
 146 }
 147
 148 static int axi_dmac_read(struct axi_dmac *axi_dmac, unsigned int reg)
 149 {
 150         return readl(axi_dmac->base + reg);
 151 }
 152
 153 static int axi_dmac_src_is_mem(struct axi_dmac_chan *chan)
 154 {
 155         return chan->src_type == AXI_DMAC_BUS_TYPE_AXI_MM;
 156 }
 157
 158 static int axi_dmac_dest_is_mem(struct axi_dmac_chan *chan)
 159 {
 160         return chan->dest_type == AXI_DMAC_BUS_TYPE_AXI_MM;
 161 }
 162
 163 static bool axi_dmac_check_len(struct axi_dmac_chan *chan, unsigned int len)
 164 {
 165         if (len == 0 || len > chan->max_length)
 166                 return false;
 167         if ((len & chan->align_mask) != 0) /* Not aligned */
 168                 return false;
 169         return true;
 170 }
 171
 172 static bool axi_dmac_check_addr(struct axi_dmac_chan *chan, dma_addr_t addr)
 173 {
 174         if ((addr & chan->align_mask) != 0) /* Not aligned */
 175                 return false;
 176         return true;
 177 }
 178
 179 static void axi_dmac_start_transfer(struct axi_dmac_chan *chan)
 180 {
 181         struct axi_dmac *dmac = chan_to_axi_dmac(chan);
 182         struct virt_dma_desc *vdesc;
 183         struct axi_dmac_desc *desc;
 184         struct axi_dmac_sg *sg;
 185         unsigned int flags = 0;
 186         unsigned int val;
 187
 188         val = axi_dmac_read(dmac, AXI_DMAC_REG_START_TRANSFER);
 189         if (val) /* Queue is full, wait for the next SOT IRQ */
 190                 return;
 191
 192         desc = chan->next_desc;
 193
 194         if (!desc) {
 195                 vdesc = vchan_next_desc(&chan->vchan);
 196                 if (!vdesc)
 197                         return;
 198                 list_move_tail(&vdesc->node, &chan->active_descs);
 199                 desc = to_axi_dmac_desc(vdesc);
 200         }
 201         sg = &desc->sg[desc->num_submitted];
 202
 203         desc->num_submitted++;
 204         if (desc->num_submitted == desc->num_sgs)
 205                 chan->next_desc = NULL;
 206         else
 207                 chan->next_desc = desc;
 208
 209         sg->id = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_ID);
 210
 211         if (axi_dmac_dest_is_mem(chan)) {
 212                 axi_dmac_write(dmac, AXI_DMAC_REG_DEST_ADDRESS, sg->dest_addr);
 213                 axi_dmac_write(dmac, AXI_DMAC_REG_DEST_STRIDE, sg->dest_stride);
 214         }
 215
 216         if (axi_dmac_src_is_mem(chan)) {
 217                 axi_dmac_write(dmac, AXI_DMAC_REG_SRC_ADDRESS, sg->src_addr);
 218                 axi_dmac_write(dmac, AXI_DMAC_REG_SRC_STRIDE, sg->src_stride);
 219         }
 220
 221         /*
 222          * If the hardware supports cyclic transfers and there is no callback to
 223          * call, enable hw cyclic mode to avoid unnecessary interrupts.
 224          */
 225         if (chan->hw_cyclic && desc->cyclic && !desc->vdesc.tx.callback)
 226                 flags |= AXI_DMAC_FLAG_CYCLIC;
 227
 228         axi_dmac_write(dmac, AXI_DMAC_REG_X_LENGTH, sg->x_len - 1);
 229         axi_dmac_write(dmac, AXI_DMAC_REG_Y_LENGTH, sg->y_len - 1);
 230         axi_dmac_write(dmac, AXI_DMAC_REG_FLAGS, flags);
 231         axi_dmac_write(dmac, AXI_DMAC_REG_START_TRANSFER, 1);
 232 }
 233
 234 static struct axi_dmac_desc *axi_dmac_active_desc(struct axi_dmac_chan *chan)
 235 {
 236         return list_first_entry_or_null(&chan->active_descs,
 237                 struct axi_dmac_desc, vdesc.node);
 238 }
 239
 240 static void axi_dmac_transfer_done(struct axi_dmac_chan *chan,
 241         unsigned int completed_transfers)
 242 {
 243         struct axi_dmac_desc *active;
 244         struct axi_dmac_sg *sg;
 245
 246         active = axi_dmac_active_desc(chan);
 247         if (!active)
 248                 return;
 249
 250         if (active->cyclic) {
 251                 vchan_cyclic_callback(&active->vdesc);
 252         } else {
 253                 do {
 254                         sg = &active->sg[active->num_completed];
 255                         if (!(BIT(sg->id) & completed_transfers))
 256                                 break;
 257                         active->num_completed++;
 258                         if (active->num_completed == active->num_sgs) {
 259                                 list_del(&active->vdesc.node);
 260                                 vchan_cookie_complete(&active->vdesc);
 261                                 active = axi_dmac_active_desc(chan);
 262                         }
 263                 } while (active);
 264         }
 265 }
 266
 267 static irqreturn_t axi_dmac_interrupt_handler(int irq, void *devid)
 268 {
 269         struct axi_dmac *dmac = devid;
 270         unsigned int pending;
 271
 272         pending = axi_dmac_read(dmac, AXI_DMAC_REG_IRQ_PENDING);
 273         if (!pending)
 274                 return IRQ_NONE;
 275
 276         axi_dmac_write(dmac, AXI_DMAC_REG_IRQ_PENDING, pending);
 277
 278         spin_lock(&dmac->chan.vchan.lock);
 279         /* One or more transfers have finished */
 280         if (pending & AXI_DMAC_IRQ_EOT) {
 281                 unsigned int completed;
 282
 283                 completed = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_DONE);
 284                 axi_dmac_transfer_done(&dmac->chan, completed);
 285         }
 286         /* Space has become available in the descriptor queue */
 287         if (pending & AXI_DMAC_IRQ_SOT)
 288                 axi_dmac_start_transfer(&dmac->chan);
 289         spin_unlock(&dmac->chan.vchan.lock);
 290
 291         return IRQ_HANDLED;
 292 }
 293
 294 static int axi_dmac_terminate_all(struct dma_chan *c)
 295 {
 296         struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
 297         struct axi_dmac *dmac = chan_to_axi_dmac(chan);
 298         unsigned long flags;
 299         LIST_HEAD(head);
 300
 301         spin_lock_irqsave(&chan->vchan.lock, flags);
 302         axi_dmac_write(dmac, AXI_DMAC_REG_CTRL, 0);
 303         chan->next_desc = NULL;
 304         vchan_get_all_descriptors(&chan->vchan, &head);
 305         list_splice_tail_init(&chan->active_descs, &head);
 306         spin_unlock_irqrestore(&chan->vchan.lock, flags);
 307
 308         vchan_dma_desc_free_list(&chan->vchan, &head);
 309
 310         return 0;
 311 }
 312
 313 static void axi_dmac_synchronize(struct dma_chan *c)
 314 {
 315         struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
 316
 317         vchan_synchronize(&chan->vchan);
 318 }
 319
 320 static void axi_dmac_issue_pending(struct dma_chan *c)
 321 {
 322         struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
 323         struct axi_dmac *dmac = chan_to_axi_dmac(chan);
 324         unsigned long flags;
 325
 326         axi_dmac_write(dmac, AXI_DMAC_REG_CTRL, AXI_DMAC_CTRL_ENABLE);
 327
 328         spin_lock_irqsave(&chan->vchan.lock, flags);
 329         if (vchan_issue_pending(&chan->vchan))
 330                 axi_dmac_start_transfer(chan);
 331         spin_unlock_irqrestore(&chan->vchan.lock, flags);
 332 }
 333
 334 static struct axi_dmac_desc *axi_dmac_alloc_desc(unsigned int num_sgs)
 335 {
 336         struct axi_dmac_desc *desc;
 337
 338         desc = kzalloc(sizeof(struct axi_dmac_desc) +
 339                 sizeof(struct axi_dmac_sg) * num_sgs, GFP_NOWAIT);
 340         if (!desc)
 341                 return NULL;
 342
 343         desc->num_sgs = num_sgs;
 344
 345         return desc;
 346 }
 347
 348 static struct dma_async_tx_descriptor *axi_dmac_prep_slave_sg(
 349         struct dma_chan *c, struct scatterlist *sgl,
 350         unsigned int sg_len, enum dma_transfer_direction direction,
 351         unsigned long flags, void *context)
 352 {
 353         struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
 354         struct axi_dmac_desc *desc;
 355         struct scatterlist *sg;
 356         unsigned int i;
 357
 358         if (direction != chan->direction)
 359                 return NULL;
 360
 361         desc = axi_dmac_alloc_desc(sg_len);
 362         if (!desc)
 363                 return NULL;
 364
 365         for_each_sg(sgl, sg, sg_len, i) {
 366                 if (!axi_dmac_check_addr(chan, sg_dma_address(sg)) ||
 367                     !axi_dmac_check_len(chan, sg_dma_len(sg))) {
 368                         kfree(desc);
 369                         return NULL;
 370                 }
 371
 372                 if (direction == DMA_DEV_TO_MEM)
 373                         desc->sg[i].dest_addr = sg_dma_address(sg);
 374                 else
 375                         desc->sg[i].src_addr = sg_dma_address(sg);
 376                 desc->sg[i].x_len = sg_dma_len(sg);
 377                 desc->sg[i].y_len = 1;
 378         }
 379
 380         desc->cyclic = false;
 381
 382         return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
 383 }
 384
 385 static struct dma_async_tx_descriptor *axi_dmac_prep_dma_cyclic(
 386         struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
 387         size_t period_len, enum dma_transfer_direction direction,
 388         unsigned long flags)
 389 {
 390         struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
 391         struct axi_dmac_desc *desc;
 392         unsigned int num_periods, i;
 393
 394         if (direction != chan->direction)
 395                 return NULL;
 396
 397         if (!axi_dmac_check_len(chan, buf_len) ||
 398             !axi_dmac_check_addr(chan, buf_addr))
 399                 return NULL;
 400
 401         if (period_len == 0 || buf_len % period_len)
 402                 return NULL;
 403
 404         num_periods = buf_len / period_len;
 405
 406         desc = axi_dmac_alloc_desc(num_periods);
 407         if (!desc)
 408                 return NULL;
 409
 410         for (i = 0; i < num_periods; i++) {
 411                 if (direction == DMA_DEV_TO_MEM)
 412                         desc->sg[i].dest_addr = buf_addr;
 413                 else
 414                         desc->sg[i].src_addr = buf_addr;
 415                 desc->sg[i].x_len = period_len;
 416                 desc->sg[i].y_len = 1;
 417                 buf_addr += period_len;
 418         }
 419
 420         desc->cyclic = true;
 421
 422         return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
 423 }
 424
 425 static struct dma_async_tx_descriptor *axi_dmac_prep_interleaved(
 426         struct dma_chan *c, struct dma_interleaved_template *xt,
 427         unsigned long flags)
 428 {
 429         struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
 430         struct axi_dmac_desc *desc;
 431         size_t dst_icg, src_icg;
 432
 433         if (xt->frame_size != 1)
 434                 return NULL;
 435
 436         if (xt->dir != chan->direction)
 437                 return NULL;
 438
 439         if (axi_dmac_src_is_mem(chan)) {
 440                 if (!xt->src_inc || !axi_dmac_check_addr(chan, xt->src_start))
 441                         return NULL;
 442         }
 443
 444         if (axi_dmac_dest_is_mem(chan)) {
 445                 if (!xt->dst_inc || !axi_dmac_check_addr(chan, xt->dst_start))
 446                         return NULL;
 447         }
 448
 449         dst_icg = dmaengine_get_dst_icg(xt, &xt->sgl[0]);
 450         src_icg = dmaengine_get_src_icg(xt, &xt->sgl[0]);
 451
 452         if (chan->hw_2d) {
 453                 if (!axi_dmac_check_len(chan, xt->sgl[0].size) ||
 454                     !axi_dmac_check_len(chan, xt->numf))
 455                         return NULL;
 456                 if (xt->sgl[0].size + dst_icg > chan->max_length ||
 457                     xt->sgl[0].size + src_icg > chan->max_length)
 458                         return NULL;
 459         } else {
 460                 if (dst_icg != 0 || src_icg != 0)
 461                         return NULL;
 462                 if (chan->max_length / xt->sgl[0].size < xt->numf)
 463                         return NULL;
 464                 if (!axi_dmac_check_len(chan, xt->sgl[0].size * xt->numf))
 465                         return NULL;
 466         }
 467
 468         desc = axi_dmac_alloc_desc(1);
 469         if (!desc)
 470                 return NULL;
 471
 472         if (axi_dmac_src_is_mem(chan)) {
 473                 desc->sg[0].src_addr = xt->src_start;
 474                 desc->sg[0].src_stride = xt->sgl[0].size + src_icg;
 475         }
 476
 477         if (axi_dmac_dest_is_mem(chan)) {
 478                 desc->sg[0].dest_addr = xt->dst_start;
 479                 desc->sg[0].dest_stride = xt->sgl[0].size + dst_icg;
 480         }
 481
 482         if (chan->hw_2d) {
 483                 desc->sg[0].x_len = xt->sgl[0].size;
 484                 desc->sg[0].y_len = xt->numf;
 485         } else {
 486                 desc->sg[0].x_len = xt->sgl[0].size * xt->numf;
 487                 desc->sg[0].y_len = 1;
 488         }
 489
 490         return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
 491 }
 492
 493 static void axi_dmac_free_chan_resources(struct dma_chan *c)
 494 {
 495         vchan_free_chan_resources(to_virt_chan(c));
 496 }
 497
 498 static void axi_dmac_desc_free(struct virt_dma_desc *vdesc)
 499 {
 500         kfree(container_of(vdesc, struct axi_dmac_desc, vdesc));
 501 }
 502
 503 /*
 504  * The configuration stored in the devicetree matches the configuration
 505  * parameters of the peripheral instance and allows the driver to know which
 506  * features are implemented and how it should behave.
 507  */
 508 static int axi_dmac_parse_chan_dt(struct device_node *of_chan,
 509         struct axi_dmac_chan *chan)
 510 {
 511         u32 val;
 512         int ret;
 513
 514         ret = of_property_read_u32(of_chan, "reg", &val);
 515         if (ret)
 516                 return ret;
 517
 518         /* We only support 1 channel for now */
 519         if (val != 0)
 520                 return -EINVAL;
 521
 522         ret = of_property_read_u32(of_chan, "adi,source-bus-type", &val);
 523         if (ret)
 524                 return ret;
 525         if (val > AXI_DMAC_BUS_TYPE_FIFO)
 526                 return -EINVAL;
 527         chan->src_type = val;
 528
 529         ret = of_property_read_u32(of_chan, "adi,destination-bus-type", &val);
 530         if (ret)
 531                 return ret;
 532         if (val > AXI_DMAC_BUS_TYPE_FIFO)
 533                 return -EINVAL;
 534         chan->dest_type = val;
 535
 536         ret = of_property_read_u32(of_chan, "adi,source-bus-width", &val);
 537         if (ret)
 538                 return ret;
 539         chan->src_width = val / 8;
 540
 541         ret = of_property_read_u32(of_chan, "adi,destination-bus-width", &val);
 542         if (ret)
 543                 return ret;
 544         chan->dest_width = val / 8;
 545
 546         ret = of_property_read_u32(of_chan, "adi,length-width", &val);
 547         if (ret)
 548                 return ret;
 549
 550         if (val >= 32)
 551                 chan->max_length = UINT_MAX;
 552         else
 553                 chan->max_length = (1ULL << val) - 1;
 554
 555         chan->align_mask = max(chan->dest_width, chan->src_width) - 1;
 556
 557         if (axi_dmac_dest_is_mem(chan) && axi_dmac_src_is_mem(chan))
 558                 chan->direction = DMA_MEM_TO_MEM;
 559         else if (!axi_dmac_dest_is_mem(chan) && axi_dmac_src_is_mem(chan))
 560                 chan->direction = DMA_MEM_TO_DEV;
 561         else if (axi_dmac_dest_is_mem(chan) && !axi_dmac_src_is_mem(chan))
 562                 chan->direction = DMA_DEV_TO_MEM;
 563         else
 564                 chan->direction = DMA_DEV_TO_DEV;
 565
 566         chan->hw_cyclic = of_property_read_bool(of_chan, "adi,cyclic");
 567         chan->hw_2d = of_property_read_bool(of_chan, "adi,2d");
 568
 569         return 0;
 570 }
 571
 572 static int axi_dmac_probe(struct platform_device *pdev)
 573 {
 574         struct device_node *of_channels, *of_chan;
 575         struct dma_device *dma_dev;
 576         struct axi_dmac *dmac;
 577         struct resource *res;
 578         int ret;
 579
 580         dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL);
 581         if (!dmac)
 582                 return -ENOMEM;
 583
 584         dmac->irq = platform_get_irq(pdev, 0);
 585         if (dmac->irq < 0)
 586                 return dmac->irq;
 587         if (dmac->irq == 0)
 588                 return -EINVAL;
 589
 590         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 591         dmac->base = devm_ioremap_resource(&pdev->dev, res);
 592         if (IS_ERR(dmac->base))
 593                 return PTR_ERR(dmac->base);
 594
 595         dmac->clk = devm_clk_get(&pdev->dev, NULL);
 596         if (IS_ERR(dmac->clk))
 597                 return PTR_ERR(dmac->clk);
 598
 599         INIT_LIST_HEAD(&dmac->chan.active_descs);
 600
 601         of_channels = of_get_child_by_name(pdev->dev.of_node, "adi,channels");
 602         if (of_channels == NULL)
 603                 return -ENODEV;
 604
 605         for_each_child_of_node(of_channels, of_chan) {
 606                 ret = axi_dmac_parse_chan_dt(of_chan, &dmac->chan);
 607                 if (ret) {
 608                         of_node_put(of_chan);
 609                         of_node_put(of_channels);
 610                         return -EINVAL;
 611                 }
 612         }
 613         of_node_put(of_channels);
 614
 615         pdev->dev.dma_parms = &dmac->dma_parms;
 616         dma_set_max_seg_size(&pdev->dev, dmac->chan.max_length);
 617
 618         dma_dev = &dmac->dma_dev;
 619         dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
 620         dma_cap_set(DMA_CYCLIC, dma_dev->cap_mask);
 621         dma_dev->device_free_chan_resources = axi_dmac_free_chan_resources;
 622         dma_dev->device_tx_status = dma_cookie_status;
 623         dma_dev->device_issue_pending = axi_dmac_issue_pending;
 624         dma_dev->device_prep_slave_sg = axi_dmac_prep_slave_sg;
 625         dma_dev->device_prep_dma_cyclic = axi_dmac_prep_dma_cyclic;
 626         dma_dev->device_prep_interleaved_dma = axi_dmac_prep_interleaved;
 627         dma_dev->device_terminate_all = axi_dmac_terminate_all;
 628         dma_dev->device_synchronize = axi_dmac_synchronize;
 629         dma_dev->dev = &pdev->dev;
 630         dma_dev->chancnt = 1;
 631         dma_dev->src_addr_widths = BIT(dmac->chan.src_width);
 632         dma_dev->dst_addr_widths = BIT(dmac->chan.dest_width);
 633         dma_dev->directions = BIT(dmac->chan.direction);
 634         dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
 635         INIT_LIST_HEAD(&dma_dev->channels);
 636
 637         dmac->chan.vchan.desc_free = axi_dmac_desc_free;
 638         vchan_init(&dmac->chan.vchan, dma_dev);
 639
 640         ret = clk_prepare_enable(dmac->clk);
 641         if (ret < 0)
 642                 return ret;
 643
 644         axi_dmac_write(dmac, AXI_DMAC_REG_IRQ_MASK, 0x00);
 645
 646         ret = dma_async_device_register(dma_dev);
 647         if (ret)
 648                 goto err_clk_disable;
 649
 650         ret = of_dma_controller_register(pdev->dev.of_node,
 651                 of_dma_xlate_by_chan_id, dma_dev);
 652         if (ret)
 653                 goto err_unregister_device;
 654
 655         ret = request_irq(dmac->irq, axi_dmac_interrupt_handler, 0,
 656                 dev_name(&pdev->dev), dmac);
 657         if (ret)
 658                 goto err_unregister_of;
 659
 660         platform_set_drvdata(pdev, dmac);
 661
 662         return 0;
 663
 664 err_unregister_of:
 665         of_dma_controller_free(pdev->dev.of_node);
 666 err_unregister_device:
 667         dma_async_device_unregister(&dmac->dma_dev);
 668 err_clk_disable:
 669         clk_disable_unprepare(dmac->clk);
 670
 671         return ret;
 672 }
 673
 674 static int axi_dmac_remove(struct platform_device *pdev)
 675 {
 676         struct axi_dmac *dmac = platform_get_drvdata(pdev);
 677
 678         of_dma_controller_free(pdev->dev.of_node);
 679         free_irq(dmac->irq, dmac);
 680         tasklet_kill(&dmac->chan.vchan.task);
 681         dma_async_device_unregister(&dmac->dma_dev);
 682         clk_disable_unprepare(dmac->clk);
 683
 684         return 0;
 685 }
 686
 687 static const struct of_device_id axi_dmac_of_match_table[] = {
 688         { .compatible = "adi,axi-dmac-1.00.a" },
 689         { },
 690 };
 691 MODULE_DEVICE_TABLE(of, axi_dmac_of_match_table);
 692
 693 static struct platform_driver axi_dmac_driver = {
 694         .driver = {
 695                 .name = "dma-axi-dmac",
 696                 .of_match_table = axi_dmac_of_match_table,
 697         },
 698         .probe = axi_dmac_probe,
 699         .remove = axi_dmac_remove,
 700 };
 701 module_platform_driver(axi_dmac_driver);
 702
 703 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 704 MODULE_DESCRIPTION("DMA controller driver for the AXI-DMAC controller");
 705 MODULE_LICENSE("GPL v2");