linux/drivers/dma/dma-axi-dmac.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Driver for the Analog Devices AXI-DMAC core
   4 *
   5 * Copyright 2013-2019 Analog Devices Inc.
   6 *  Author: Lars-Peter Clausen <lars@metafoo.de>
   7 */
   8
   9#include <linux/bitfield.h>
  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/regmap.h>
  23#include <linux/slab.h>
  24#include <linux/fpga/adi-axi-common.h>
  25
  26#include <dt-bindings/dma/axi-dmac.h>
  27
  28#include "dmaengine.h"
  29#include "virt-dma.h"
  30
  31/*
  32 * The AXI-DMAC is a soft IP core that is used in FPGA designs. The core has
  33 * various instantiation parameters which decided the exact feature set support
  34 * by the core.
  35 *
  36 * Each channel of the core has a source interface and a destination interface.
  37 * The number of channels and the type of the channel interfaces is selected at
  38 * configuration time. A interface can either be a connected to a central memory
  39 * interconnect, which allows access to system memory, or it can be connected to
  40 * a dedicated bus which is directly connected to a data port on a peripheral.
  41 * Given that those are configuration options of the core that are selected when
  42 * it is instantiated this means that they can not be changed by software at
  43 * runtime. By extension this means that each channel is uni-directional. It can
  44 * either be device to memory or memory to device, but not both. Also since the
  45 * device side is a dedicated data bus only connected to a single peripheral
  46 * there is no address than can or needs to be configured for the device side.
  47 */
  48
  49#define AXI_DMAC_REG_INTERFACE_DESC     0x10
  50#define   AXI_DMAC_DMA_SRC_TYPE_MSK     GENMASK(13, 12)
  51#define   AXI_DMAC_DMA_SRC_TYPE_GET(x)  FIELD_GET(AXI_DMAC_DMA_SRC_TYPE_MSK, x)
  52#define   AXI_DMAC_DMA_SRC_WIDTH_MSK    GENMASK(11, 8)
  53#define   AXI_DMAC_DMA_SRC_WIDTH_GET(x) FIELD_GET(AXI_DMAC_DMA_SRC_WIDTH_MSK, x)
  54#define   AXI_DMAC_DMA_DST_TYPE_MSK     GENMASK(5, 4)
  55#define   AXI_DMAC_DMA_DST_TYPE_GET(x)  FIELD_GET(AXI_DMAC_DMA_DST_TYPE_MSK, x)
  56#define   AXI_DMAC_DMA_DST_WIDTH_MSK    GENMASK(3, 0)
  57#define   AXI_DMAC_DMA_DST_WIDTH_GET(x) FIELD_GET(AXI_DMAC_DMA_DST_WIDTH_MSK, x)
  58
  59#define AXI_DMAC_REG_IRQ_MASK           0x80
  60#define AXI_DMAC_REG_IRQ_PENDING        0x84
  61#define AXI_DMAC_REG_IRQ_SOURCE         0x88
  62
  63#define AXI_DMAC_REG_CTRL               0x400
  64#define AXI_DMAC_REG_TRANSFER_ID        0x404
  65#define AXI_DMAC_REG_START_TRANSFER     0x408
  66#define AXI_DMAC_REG_FLAGS              0x40c
  67#define AXI_DMAC_REG_DEST_ADDRESS       0x410
  68#define AXI_DMAC_REG_SRC_ADDRESS        0x414
  69#define AXI_DMAC_REG_X_LENGTH           0x418
  70#define AXI_DMAC_REG_Y_LENGTH           0x41c
  71#define AXI_DMAC_REG_DEST_STRIDE        0x420
  72#define AXI_DMAC_REG_SRC_STRIDE         0x424
  73#define AXI_DMAC_REG_TRANSFER_DONE      0x428
  74#define AXI_DMAC_REG_ACTIVE_TRANSFER_ID 0x42c
  75#define AXI_DMAC_REG_STATUS             0x430
  76#define AXI_DMAC_REG_CURRENT_SRC_ADDR   0x434
  77#define AXI_DMAC_REG_CURRENT_DEST_ADDR  0x438
  78#define AXI_DMAC_REG_PARTIAL_XFER_LEN   0x44c
  79#define AXI_DMAC_REG_PARTIAL_XFER_ID    0x450
  80
  81#define AXI_DMAC_CTRL_ENABLE            BIT(0)
  82#define AXI_DMAC_CTRL_PAUSE             BIT(1)
  83
  84#define AXI_DMAC_IRQ_SOT                BIT(0)
  85#define AXI_DMAC_IRQ_EOT                BIT(1)
  86
  87#define AXI_DMAC_FLAG_CYCLIC            BIT(0)
  88#define AXI_DMAC_FLAG_LAST              BIT(1)
  89#define AXI_DMAC_FLAG_PARTIAL_REPORT    BIT(2)
  90
  91#define AXI_DMAC_FLAG_PARTIAL_XFER_DONE BIT(31)
  92
  93/* The maximum ID allocated by the hardware is 31 */
  94#define AXI_DMAC_SG_UNUSED 32U
  95
  96struct axi_dmac_sg {
  97        dma_addr_t src_addr;
  98        dma_addr_t dest_addr;
  99        unsigned int x_len;
 100        unsigned int y_len;
 101        unsigned int dest_stride;
 102        unsigned int src_stride;
 103        unsigned int id;
 104        unsigned int partial_len;
 105        bool schedule_when_free;
 106};
 107
 108struct axi_dmac_desc {
 109        struct virt_dma_desc vdesc;
 110        bool cyclic;
 111        bool have_partial_xfer;
 112
 113        unsigned int num_submitted;
 114        unsigned int num_completed;
 115        unsigned int num_sgs;
 116        struct axi_dmac_sg sg[];
 117};
 118
 119struct axi_dmac_chan {
 120        struct virt_dma_chan vchan;
 121
 122        struct axi_dmac_desc *next_desc;
 123        struct list_head active_descs;
 124        enum dma_transfer_direction direction;
 125
 126        unsigned int src_width;
 127        unsigned int dest_width;
 128        unsigned int src_type;
 129        unsigned int dest_type;
 130
 131        unsigned int max_length;
 132        unsigned int address_align_mask;
 133        unsigned int length_align_mask;
 134
 135        bool hw_partial_xfer;
 136        bool hw_cyclic;
 137        bool hw_2d;
 138};
 139
 140struct axi_dmac {
 141        void __iomem *base;
 142        int irq;
 143
 144        struct clk *clk;
 145
 146        struct dma_device dma_dev;
 147        struct axi_dmac_chan chan;
 148};
 149
 150static struct axi_dmac *chan_to_axi_dmac(struct axi_dmac_chan *chan)
 151{
 152        return container_of(chan->vchan.chan.device, struct axi_dmac,
 153                dma_dev);
 154}
 155
 156static struct axi_dmac_chan *to_axi_dmac_chan(struct dma_chan *c)
 157{
 158        return container_of(c, struct axi_dmac_chan, vchan.chan);
 159}
 160
 161static struct axi_dmac_desc *to_axi_dmac_desc(struct virt_dma_desc *vdesc)
 162{
 163        return container_of(vdesc, struct axi_dmac_desc, vdesc);
 164}
 165
 166static void axi_dmac_write(struct axi_dmac *axi_dmac, unsigned int reg,
 167        unsigned int val)
 168{
 169        writel(val, axi_dmac->base + reg);
 170}
 171
 172static int axi_dmac_read(struct axi_dmac *axi_dmac, unsigned int reg)
 173{
 174        return readl(axi_dmac->base + reg);
 175}
 176
 177static int axi_dmac_src_is_mem(struct axi_dmac_chan *chan)
 178{
 179        return chan->src_type == AXI_DMAC_BUS_TYPE_AXI_MM;
 180}
 181
 182static int axi_dmac_dest_is_mem(struct axi_dmac_chan *chan)
 183{
 184        return chan->dest_type == AXI_DMAC_BUS_TYPE_AXI_MM;
 185}
 186
 187static bool axi_dmac_check_len(struct axi_dmac_chan *chan, unsigned int len)
 188{
 189        if (len == 0)
 190                return false;
 191        if ((len & chan->length_align_mask) != 0) /* Not aligned */
 192                return false;
 193        return true;
 194}
 195
 196static bool axi_dmac_check_addr(struct axi_dmac_chan *chan, dma_addr_t addr)
 197{
 198        if ((addr & chan->address_align_mask) != 0) /* Not aligned */
 199                return false;
 200        return true;
 201}
 202
 203static void axi_dmac_start_transfer(struct axi_dmac_chan *chan)
 204{
 205        struct axi_dmac *dmac = chan_to_axi_dmac(chan);
 206        struct virt_dma_desc *vdesc;
 207        struct axi_dmac_desc *desc;
 208        struct axi_dmac_sg *sg;
 209        unsigned int flags = 0;
 210        unsigned int val;
 211
 212        val = axi_dmac_read(dmac, AXI_DMAC_REG_START_TRANSFER);
 213        if (val) /* Queue is full, wait for the next SOT IRQ */
 214                return;
 215
 216        desc = chan->next_desc;
 217
 218        if (!desc) {
 219                vdesc = vchan_next_desc(&chan->vchan);
 220                if (!vdesc)
 221                        return;
 222                list_move_tail(&vdesc->node, &chan->active_descs);
 223                desc = to_axi_dmac_desc(vdesc);
 224        }
 225        sg = &desc->sg[desc->num_submitted];
 226
 227        /* Already queued in cyclic mode. Wait for it to finish */
 228        if (sg->id != AXI_DMAC_SG_UNUSED) {
 229                sg->schedule_when_free = true;
 230                return;
 231        }
 232
 233        desc->num_submitted++;
 234        if (desc->num_submitted == desc->num_sgs ||
 235            desc->have_partial_xfer) {
 236                if (desc->cyclic)
 237                        desc->num_submitted = 0; /* Start again */
 238                else
 239                        chan->next_desc = NULL;
 240                flags |= AXI_DMAC_FLAG_LAST;
 241        } else {
 242                chan->next_desc = desc;
 243        }
 244
 245        sg->id = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_ID);
 246
 247        if (axi_dmac_dest_is_mem(chan)) {
 248                axi_dmac_write(dmac, AXI_DMAC_REG_DEST_ADDRESS, sg->dest_addr);
 249                axi_dmac_write(dmac, AXI_DMAC_REG_DEST_STRIDE, sg->dest_stride);
 250        }
 251
 252        if (axi_dmac_src_is_mem(chan)) {
 253                axi_dmac_write(dmac, AXI_DMAC_REG_SRC_ADDRESS, sg->src_addr);
 254                axi_dmac_write(dmac, AXI_DMAC_REG_SRC_STRIDE, sg->src_stride);
 255        }
 256
 257        /*
 258         * If the hardware supports cyclic transfers and there is no callback to
 259         * call and only a single segment, enable hw cyclic mode to avoid
 260         * unnecessary interrupts.
 261         */
 262        if (chan->hw_cyclic && desc->cyclic && !desc->vdesc.tx.callback &&
 263                desc->num_sgs == 1)
 264                flags |= AXI_DMAC_FLAG_CYCLIC;
 265
 266        if (chan->hw_partial_xfer)
 267                flags |= AXI_DMAC_FLAG_PARTIAL_REPORT;
 268
 269        axi_dmac_write(dmac, AXI_DMAC_REG_X_LENGTH, sg->x_len - 1);
 270        axi_dmac_write(dmac, AXI_DMAC_REG_Y_LENGTH, sg->y_len - 1);
 271        axi_dmac_write(dmac, AXI_DMAC_REG_FLAGS, flags);
 272        axi_dmac_write(dmac, AXI_DMAC_REG_START_TRANSFER, 1);
 273}
 274
 275static struct axi_dmac_desc *axi_dmac_active_desc(struct axi_dmac_chan *chan)
 276{
 277        return list_first_entry_or_null(&chan->active_descs,
 278                struct axi_dmac_desc, vdesc.node);
 279}
 280
 281static inline unsigned int axi_dmac_total_sg_bytes(struct axi_dmac_chan *chan,
 282        struct axi_dmac_sg *sg)
 283{
 284        if (chan->hw_2d)
 285                return sg->x_len * sg->y_len;
 286        else
 287                return sg->x_len;
 288}
 289
 290static void axi_dmac_dequeue_partial_xfers(struct axi_dmac_chan *chan)
 291{
 292        struct axi_dmac *dmac = chan_to_axi_dmac(chan);
 293        struct axi_dmac_desc *desc;
 294        struct axi_dmac_sg *sg;
 295        u32 xfer_done, len, id, i;
 296        bool found_sg;
 297
 298        do {
 299                len = axi_dmac_read(dmac, AXI_DMAC_REG_PARTIAL_XFER_LEN);
 300                id  = axi_dmac_read(dmac, AXI_DMAC_REG_PARTIAL_XFER_ID);
 301
 302                found_sg = false;
 303                list_for_each_entry(desc, &chan->active_descs, vdesc.node) {
 304                        for (i = 0; i < desc->num_sgs; i++) {
 305                                sg = &desc->sg[i];
 306                                if (sg->id == AXI_DMAC_SG_UNUSED)
 307                                        continue;
 308                                if (sg->id == id) {
 309                                        desc->have_partial_xfer = true;
 310                                        sg->partial_len = len;
 311                                        found_sg = true;
 312                                        break;
 313                                }
 314                        }
 315                        if (found_sg)
 316                                break;
 317                }
 318
 319                if (found_sg) {
 320                        dev_dbg(dmac->dma_dev.dev,
 321                                "Found partial segment id=%u, len=%u\n",
 322                                id, len);
 323                } else {
 324                        dev_warn(dmac->dma_dev.dev,
 325                                 "Not found partial segment id=%u, len=%u\n",
 326                                 id, len);
 327                }
 328
 329                /* Check if we have any more partial transfers */
 330                xfer_done = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_DONE);
 331                xfer_done = !(xfer_done & AXI_DMAC_FLAG_PARTIAL_XFER_DONE);
 332
 333        } while (!xfer_done);
 334}
 335
 336static void axi_dmac_compute_residue(struct axi_dmac_chan *chan,
 337        struct axi_dmac_desc *active)
 338{
 339        struct dmaengine_result *rslt = &active->vdesc.tx_result;
 340        unsigned int start = active->num_completed - 1;
 341        struct axi_dmac_sg *sg;
 342        unsigned int i, total;
 343
 344        rslt->result = DMA_TRANS_NOERROR;
 345        rslt->residue = 0;
 346
 347        /*
 348         * We get here if the last completed segment is partial, which
 349         * means we can compute the residue from that segment onwards
 350         */
 351        for (i = start; i < active->num_sgs; i++) {
 352                sg = &active->sg[i];
 353                total = axi_dmac_total_sg_bytes(chan, sg);
 354                rslt->residue += (total - sg->partial_len);
 355        }
 356}
 357
 358static bool axi_dmac_transfer_done(struct axi_dmac_chan *chan,
 359        unsigned int completed_transfers)
 360{
 361        struct axi_dmac_desc *active;
 362        struct axi_dmac_sg *sg;
 363        bool start_next = false;
 364
 365        active = axi_dmac_active_desc(chan);
 366        if (!active)
 367                return false;
 368
 369        if (chan->hw_partial_xfer &&
 370            (completed_transfers & AXI_DMAC_FLAG_PARTIAL_XFER_DONE))
 371                axi_dmac_dequeue_partial_xfers(chan);
 372
 373        do {
 374                sg = &active->sg[active->num_completed];
 375                if (sg->id == AXI_DMAC_SG_UNUSED) /* Not yet submitted */
 376                        break;
 377                if (!(BIT(sg->id) & completed_transfers))
 378                        break;
 379                active->num_completed++;
 380                sg->id = AXI_DMAC_SG_UNUSED;
 381                if (sg->schedule_when_free) {
 382                        sg->schedule_when_free = false;
 383                        start_next = true;
 384                }
 385
 386                if (sg->partial_len)
 387                        axi_dmac_compute_residue(chan, active);
 388
 389                if (active->cyclic)
 390                        vchan_cyclic_callback(&active->vdesc);
 391
 392                if (active->num_completed == active->num_sgs ||
 393                    sg->partial_len) {
 394                        if (active->cyclic) {
 395                                active->num_completed = 0; /* wrap around */
 396                        } else {
 397                                list_del(&active->vdesc.node);
 398                                vchan_cookie_complete(&active->vdesc);
 399                                active = axi_dmac_active_desc(chan);
 400                        }
 401                }
 402        } while (active);
 403
 404        return start_next;
 405}
 406
 407static irqreturn_t axi_dmac_interrupt_handler(int irq, void *devid)
 408{
 409        struct axi_dmac *dmac = devid;
 410        unsigned int pending;
 411        bool start_next = false;
 412
 413        pending = axi_dmac_read(dmac, AXI_DMAC_REG_IRQ_PENDING);
 414        if (!pending)
 415                return IRQ_NONE;
 416
 417        axi_dmac_write(dmac, AXI_DMAC_REG_IRQ_PENDING, pending);
 418
 419        spin_lock(&dmac->chan.vchan.lock);
 420        /* One or more transfers have finished */
 421        if (pending & AXI_DMAC_IRQ_EOT) {
 422                unsigned int completed;
 423
 424                completed = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_DONE);
 425                start_next = axi_dmac_transfer_done(&dmac->chan, completed);
 426        }
 427        /* Space has become available in the descriptor queue */
 428        if ((pending & AXI_DMAC_IRQ_SOT) || start_next)
 429                axi_dmac_start_transfer(&dmac->chan);
 430        spin_unlock(&dmac->chan.vchan.lock);
 431
 432        return IRQ_HANDLED;
 433}
 434
 435static int axi_dmac_terminate_all(struct dma_chan *c)
 436{
 437        struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
 438        struct axi_dmac *dmac = chan_to_axi_dmac(chan);
 439        unsigned long flags;
 440        LIST_HEAD(head);
 441
 442        spin_lock_irqsave(&chan->vchan.lock, flags);
 443        axi_dmac_write(dmac, AXI_DMAC_REG_CTRL, 0);
 444        chan->next_desc = NULL;
 445        vchan_get_all_descriptors(&chan->vchan, &head);
 446        list_splice_tail_init(&chan->active_descs, &head);
 447        spin_unlock_irqrestore(&chan->vchan.lock, flags);
 448
 449        vchan_dma_desc_free_list(&chan->vchan, &head);
 450
 451        return 0;
 452}
 453
 454static void axi_dmac_synchronize(struct dma_chan *c)
 455{
 456        struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
 457
 458        vchan_synchronize(&chan->vchan);
 459}
 460
 461static void axi_dmac_issue_pending(struct dma_chan *c)
 462{
 463        struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
 464        struct axi_dmac *dmac = chan_to_axi_dmac(chan);
 465        unsigned long flags;
 466
 467        axi_dmac_write(dmac, AXI_DMAC_REG_CTRL, AXI_DMAC_CTRL_ENABLE);
 468
 469        spin_lock_irqsave(&chan->vchan.lock, flags);
 470        if (vchan_issue_pending(&chan->vchan))
 471                axi_dmac_start_transfer(chan);
 472        spin_unlock_irqrestore(&chan->vchan.lock, flags);
 473}
 474
 475static struct axi_dmac_desc *axi_dmac_alloc_desc(unsigned int num_sgs)
 476{
 477        struct axi_dmac_desc *desc;
 478        unsigned int i;
 479
 480        desc = kzalloc(struct_size(desc, sg, num_sgs), GFP_NOWAIT);
 481        if (!desc)
 482                return NULL;
 483
 484        for (i = 0; i < num_sgs; i++)
 485                desc->sg[i].id = AXI_DMAC_SG_UNUSED;
 486
 487        desc->num_sgs = num_sgs;
 488
 489        return desc;
 490}
 491
 492static struct axi_dmac_sg *axi_dmac_fill_linear_sg(struct axi_dmac_chan *chan,
 493        enum dma_transfer_direction direction, dma_addr_t addr,
 494        unsigned int num_periods, unsigned int period_len,
 495        struct axi_dmac_sg *sg)
 496{
 497        unsigned int num_segments, i;
 498        unsigned int segment_size;
 499        unsigned int len;
 500
 501        /* Split into multiple equally sized segments if necessary */
 502        num_segments = DIV_ROUND_UP(period_len, chan->max_length);
 503        segment_size = DIV_ROUND_UP(period_len, num_segments);
 504        /* Take care of alignment */
 505        segment_size = ((segment_size - 1) | chan->length_align_mask) + 1;
 506
 507        for (i = 0; i < num_periods; i++) {
 508                len = period_len;
 509
 510                while (len > segment_size) {
 511                        if (direction == DMA_DEV_TO_MEM)
 512                                sg->dest_addr = addr;
 513                        else
 514                                sg->src_addr = addr;
 515                        sg->x_len = segment_size;
 516                        sg->y_len = 1;
 517                        sg++;
 518                        addr += segment_size;
 519                        len -= segment_size;
 520                }
 521
 522                if (direction == DMA_DEV_TO_MEM)
 523                        sg->dest_addr = addr;
 524                else
 525                        sg->src_addr = addr;
 526                sg->x_len = len;
 527                sg->y_len = 1;
 528                sg++;
 529                addr += len;
 530        }
 531
 532        return sg;
 533}
 534
 535static struct dma_async_tx_descriptor *axi_dmac_prep_slave_sg(
 536        struct dma_chan *c, struct scatterlist *sgl,
 537        unsigned int sg_len, enum dma_transfer_direction direction,
 538        unsigned long flags, void *context)
 539{
 540        struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
 541        struct axi_dmac_desc *desc;
 542        struct axi_dmac_sg *dsg;
 543        struct scatterlist *sg;
 544        unsigned int num_sgs;
 545        unsigned int i;
 546
 547        if (direction != chan->direction)
 548                return NULL;
 549
 550        num_sgs = 0;
 551        for_each_sg(sgl, sg, sg_len, i)
 552                num_sgs += DIV_ROUND_UP(sg_dma_len(sg), chan->max_length);
 553
 554        desc = axi_dmac_alloc_desc(num_sgs);
 555        if (!desc)
 556                return NULL;
 557
 558        dsg = desc->sg;
 559
 560        for_each_sg(sgl, sg, sg_len, i) {
 561                if (!axi_dmac_check_addr(chan, sg_dma_address(sg)) ||
 562                    !axi_dmac_check_len(chan, sg_dma_len(sg))) {
 563                        kfree(desc);
 564                        return NULL;
 565                }
 566
 567                dsg = axi_dmac_fill_linear_sg(chan, direction, sg_dma_address(sg), 1,
 568                        sg_dma_len(sg), dsg);
 569        }
 570
 571        desc->cyclic = false;
 572
 573        return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
 574}
 575
 576static struct dma_async_tx_descriptor *axi_dmac_prep_dma_cyclic(
 577        struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
 578        size_t period_len, enum dma_transfer_direction direction,
 579        unsigned long flags)
 580{
 581        struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
 582        struct axi_dmac_desc *desc;
 583        unsigned int num_periods, num_segments;
 584
 585        if (direction != chan->direction)
 586                return NULL;
 587
 588        if (!axi_dmac_check_len(chan, buf_len) ||
 589            !axi_dmac_check_addr(chan, buf_addr))
 590                return NULL;
 591
 592        if (period_len == 0 || buf_len % period_len)
 593                return NULL;
 594
 595        num_periods = buf_len / period_len;
 596        num_segments = DIV_ROUND_UP(period_len, chan->max_length);
 597
 598        desc = axi_dmac_alloc_desc(num_periods * num_segments);
 599        if (!desc)
 600                return NULL;
 601
 602        axi_dmac_fill_linear_sg(chan, direction, buf_addr, num_periods,
 603                period_len, desc->sg);
 604
 605        desc->cyclic = true;
 606
 607        return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
 608}
 609
 610static struct dma_async_tx_descriptor *axi_dmac_prep_interleaved(
 611        struct dma_chan *c, struct dma_interleaved_template *xt,
 612        unsigned long flags)
 613{
 614        struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
 615        struct axi_dmac_desc *desc;
 616        size_t dst_icg, src_icg;
 617
 618        if (xt->frame_size != 1)
 619                return NULL;
 620
 621        if (xt->dir != chan->direction)
 622                return NULL;
 623
 624        if (axi_dmac_src_is_mem(chan)) {
 625                if (!xt->src_inc || !axi_dmac_check_addr(chan, xt->src_start))
 626                        return NULL;
 627        }
 628
 629        if (axi_dmac_dest_is_mem(chan)) {
 630                if (!xt->dst_inc || !axi_dmac_check_addr(chan, xt->dst_start))
 631                        return NULL;
 632        }
 633
 634        dst_icg = dmaengine_get_dst_icg(xt, &xt->sgl[0]);
 635        src_icg = dmaengine_get_src_icg(xt, &xt->sgl[0]);
 636
 637        if (chan->hw_2d) {
 638                if (!axi_dmac_check_len(chan, xt->sgl[0].size) ||
 639                    xt->numf == 0)
 640                        return NULL;
 641                if (xt->sgl[0].size + dst_icg > chan->max_length ||
 642                    xt->sgl[0].size + src_icg > chan->max_length)
 643                        return NULL;
 644        } else {
 645                if (dst_icg != 0 || src_icg != 0)
 646                        return NULL;
 647                if (chan->max_length / xt->sgl[0].size < xt->numf)
 648                        return NULL;
 649                if (!axi_dmac_check_len(chan, xt->sgl[0].size * xt->numf))
 650                        return NULL;
 651        }
 652
 653        desc = axi_dmac_alloc_desc(1);
 654        if (!desc)
 655                return NULL;
 656
 657        if (axi_dmac_src_is_mem(chan)) {
 658                desc->sg[0].src_addr = xt->src_start;
 659                desc->sg[0].src_stride = xt->sgl[0].size + src_icg;
 660        }
 661
 662        if (axi_dmac_dest_is_mem(chan)) {
 663                desc->sg[0].dest_addr = xt->dst_start;
 664                desc->sg[0].dest_stride = xt->sgl[0].size + dst_icg;
 665        }
 666
 667        if (chan->hw_2d) {
 668                desc->sg[0].x_len = xt->sgl[0].size;
 669                desc->sg[0].y_len = xt->numf;
 670        } else {
 671                desc->sg[0].x_len = xt->sgl[0].size * xt->numf;
 672                desc->sg[0].y_len = 1;
 673        }
 674
 675        if (flags & DMA_CYCLIC)
 676                desc->cyclic = true;
 677
 678        return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
 679}
 680
 681static void axi_dmac_free_chan_resources(struct dma_chan *c)
 682{
 683        vchan_free_chan_resources(to_virt_chan(c));
 684}
 685
 686static void axi_dmac_desc_free(struct virt_dma_desc *vdesc)
 687{
 688        kfree(container_of(vdesc, struct axi_dmac_desc, vdesc));
 689}
 690
 691static bool axi_dmac_regmap_rdwr(struct device *dev, unsigned int reg)
 692{
 693        switch (reg) {
 694        case AXI_DMAC_REG_IRQ_MASK:
 695        case AXI_DMAC_REG_IRQ_SOURCE:
 696        case AXI_DMAC_REG_IRQ_PENDING:
 697        case AXI_DMAC_REG_CTRL:
 698        case AXI_DMAC_REG_TRANSFER_ID:
 699        case AXI_DMAC_REG_START_TRANSFER:
 700        case AXI_DMAC_REG_FLAGS:
 701        case AXI_DMAC_REG_DEST_ADDRESS:
 702        case AXI_DMAC_REG_SRC_ADDRESS:
 703        case AXI_DMAC_REG_X_LENGTH:
 704        case AXI_DMAC_REG_Y_LENGTH:
 705        case AXI_DMAC_REG_DEST_STRIDE:
 706        case AXI_DMAC_REG_SRC_STRIDE:
 707        case AXI_DMAC_REG_TRANSFER_DONE:
 708        case AXI_DMAC_REG_ACTIVE_TRANSFER_ID:
 709        case AXI_DMAC_REG_STATUS:
 710        case AXI_DMAC_REG_CURRENT_SRC_ADDR:
 711        case AXI_DMAC_REG_CURRENT_DEST_ADDR:
 712        case AXI_DMAC_REG_PARTIAL_XFER_LEN:
 713        case AXI_DMAC_REG_PARTIAL_XFER_ID:
 714                return true;
 715        default:
 716                return false;
 717        }
 718}
 719
 720static const struct regmap_config axi_dmac_regmap_config = {
 721        .reg_bits = 32,
 722        .val_bits = 32,
 723        .reg_stride = 4,
 724        .max_register = AXI_DMAC_REG_PARTIAL_XFER_ID,
 725        .readable_reg = axi_dmac_regmap_rdwr,
 726        .writeable_reg = axi_dmac_regmap_rdwr,
 727};
 728
 729static void axi_dmac_adjust_chan_params(struct axi_dmac_chan *chan)
 730{
 731        chan->address_align_mask = max(chan->dest_width, chan->src_width) - 1;
 732
 733        if (axi_dmac_dest_is_mem(chan) && axi_dmac_src_is_mem(chan))
 734                chan->direction = DMA_MEM_TO_MEM;
 735        else if (!axi_dmac_dest_is_mem(chan) && axi_dmac_src_is_mem(chan))
 736                chan->direction = DMA_MEM_TO_DEV;
 737        else if (axi_dmac_dest_is_mem(chan) && !axi_dmac_src_is_mem(chan))
 738                chan->direction = DMA_DEV_TO_MEM;
 739        else
 740                chan->direction = DMA_DEV_TO_DEV;
 741}
 742
 743/*
 744 * The configuration stored in the devicetree matches the configuration
 745 * parameters of the peripheral instance and allows the driver to know which
 746 * features are implemented and how it should behave.
 747 */
 748static int axi_dmac_parse_chan_dt(struct device_node *of_chan,
 749        struct axi_dmac_chan *chan)
 750{
 751        u32 val;
 752        int ret;
 753
 754        ret = of_property_read_u32(of_chan, "reg", &val);
 755        if (ret)
 756                return ret;
 757
 758        /* We only support 1 channel for now */
 759        if (val != 0)
 760                return -EINVAL;
 761
 762        ret = of_property_read_u32(of_chan, "adi,source-bus-type", &val);
 763        if (ret)
 764                return ret;
 765        if (val > AXI_DMAC_BUS_TYPE_FIFO)
 766                return -EINVAL;
 767        chan->src_type = val;
 768
 769        ret = of_property_read_u32(of_chan, "adi,destination-bus-type", &val);
 770        if (ret)
 771                return ret;
 772        if (val > AXI_DMAC_BUS_TYPE_FIFO)
 773                return -EINVAL;
 774        chan->dest_type = val;
 775
 776        ret = of_property_read_u32(of_chan, "adi,source-bus-width", &val);
 777        if (ret)
 778                return ret;
 779        chan->src_width = val / 8;
 780
 781        ret = of_property_read_u32(of_chan, "adi,destination-bus-width", &val);
 782        if (ret)
 783                return ret;
 784        chan->dest_width = val / 8;
 785
 786        axi_dmac_adjust_chan_params(chan);
 787
 788        return 0;
 789}
 790
 791static int axi_dmac_parse_dt(struct device *dev, struct axi_dmac *dmac)
 792{
 793        struct device_node *of_channels, *of_chan;
 794        int ret;
 795
 796        of_channels = of_get_child_by_name(dev->of_node, "adi,channels");
 797        if (of_channels == NULL)
 798                return -ENODEV;
 799
 800        for_each_child_of_node(of_channels, of_chan) {
 801                ret = axi_dmac_parse_chan_dt(of_chan, &dmac->chan);
 802                if (ret) {
 803                        of_node_put(of_chan);
 804                        of_node_put(of_channels);
 805                        return -EINVAL;
 806                }
 807        }
 808        of_node_put(of_channels);
 809
 810        return 0;
 811}
 812
 813static int axi_dmac_read_chan_config(struct device *dev, struct axi_dmac *dmac)
 814{
 815        struct axi_dmac_chan *chan = &dmac->chan;
 816        unsigned int val, desc;
 817
 818        desc = axi_dmac_read(dmac, AXI_DMAC_REG_INTERFACE_DESC);
 819        if (desc == 0) {
 820                dev_err(dev, "DMA interface register reads zero\n");
 821                return -EFAULT;
 822        }
 823
 824        val = AXI_DMAC_DMA_SRC_TYPE_GET(desc);
 825        if (val > AXI_DMAC_BUS_TYPE_FIFO) {
 826                dev_err(dev, "Invalid source bus type read: %d\n", val);
 827                return -EINVAL;
 828        }
 829        chan->src_type = val;
 830
 831        val = AXI_DMAC_DMA_DST_TYPE_GET(desc);
 832        if (val > AXI_DMAC_BUS_TYPE_FIFO) {
 833                dev_err(dev, "Invalid destination bus type read: %d\n", val);
 834                return -EINVAL;
 835        }
 836        chan->dest_type = val;
 837
 838        val = AXI_DMAC_DMA_SRC_WIDTH_GET(desc);
 839        if (val == 0) {
 840                dev_err(dev, "Source bus width is zero\n");
 841                return -EINVAL;
 842        }
 843        /* widths are stored in log2 */
 844        chan->src_width = 1 << val;
 845
 846        val = AXI_DMAC_DMA_DST_WIDTH_GET(desc);
 847        if (val == 0) {
 848                dev_err(dev, "Destination bus width is zero\n");
 849                return -EINVAL;
 850        }
 851        chan->dest_width = 1 << val;
 852
 853        axi_dmac_adjust_chan_params(chan);
 854
 855        return 0;
 856}
 857
 858static int axi_dmac_detect_caps(struct axi_dmac *dmac, unsigned int version)
 859{
 860        struct axi_dmac_chan *chan = &dmac->chan;
 861
 862        axi_dmac_write(dmac, AXI_DMAC_REG_FLAGS, AXI_DMAC_FLAG_CYCLIC);
 863        if (axi_dmac_read(dmac, AXI_DMAC_REG_FLAGS) == AXI_DMAC_FLAG_CYCLIC)
 864                chan->hw_cyclic = true;
 865
 866        axi_dmac_write(dmac, AXI_DMAC_REG_Y_LENGTH, 1);
 867        if (axi_dmac_read(dmac, AXI_DMAC_REG_Y_LENGTH) == 1)
 868                chan->hw_2d = true;
 869
 870        axi_dmac_write(dmac, AXI_DMAC_REG_X_LENGTH, 0xffffffff);
 871        chan->max_length = axi_dmac_read(dmac, AXI_DMAC_REG_X_LENGTH);
 872        if (chan->max_length != UINT_MAX)
 873                chan->max_length++;
 874
 875        axi_dmac_write(dmac, AXI_DMAC_REG_DEST_ADDRESS, 0xffffffff);
 876        if (axi_dmac_read(dmac, AXI_DMAC_REG_DEST_ADDRESS) == 0 &&
 877            chan->dest_type == AXI_DMAC_BUS_TYPE_AXI_MM) {
 878                dev_err(dmac->dma_dev.dev,
 879                        "Destination memory-mapped interface not supported.");
 880                return -ENODEV;
 881        }
 882
 883        axi_dmac_write(dmac, AXI_DMAC_REG_SRC_ADDRESS, 0xffffffff);
 884        if (axi_dmac_read(dmac, AXI_DMAC_REG_SRC_ADDRESS) == 0 &&
 885            chan->src_type == AXI_DMAC_BUS_TYPE_AXI_MM) {
 886                dev_err(dmac->dma_dev.dev,
 887                        "Source memory-mapped interface not supported.");
 888                return -ENODEV;
 889        }
 890
 891        if (version >= ADI_AXI_PCORE_VER(4, 2, 'a'))
 892                chan->hw_partial_xfer = true;
 893
 894        if (version >= ADI_AXI_PCORE_VER(4, 1, 'a')) {
 895                axi_dmac_write(dmac, AXI_DMAC_REG_X_LENGTH, 0x00);
 896                chan->length_align_mask =
 897                        axi_dmac_read(dmac, AXI_DMAC_REG_X_LENGTH);
 898        } else {
 899                chan->length_align_mask = chan->address_align_mask;
 900        }
 901
 902        return 0;
 903}
 904
 905static int axi_dmac_probe(struct platform_device *pdev)
 906{
 907        struct dma_device *dma_dev;
 908        struct axi_dmac *dmac;
 909        struct resource *res;
 910        struct regmap *regmap;
 911        unsigned int version;
 912        int ret;
 913
 914        dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL);
 915        if (!dmac)
 916                return -ENOMEM;
 917
 918        dmac->irq = platform_get_irq(pdev, 0);
 919        if (dmac->irq < 0)
 920                return dmac->irq;
 921        if (dmac->irq == 0)
 922                return -EINVAL;
 923
 924        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 925        dmac->base = devm_ioremap_resource(&pdev->dev, res);
 926        if (IS_ERR(dmac->base))
 927                return PTR_ERR(dmac->base);
 928
 929        dmac->clk = devm_clk_get(&pdev->dev, NULL);
 930        if (IS_ERR(dmac->clk))
 931                return PTR_ERR(dmac->clk);
 932
 933        ret = clk_prepare_enable(dmac->clk);
 934        if (ret < 0)
 935                return ret;
 936
 937        version = axi_dmac_read(dmac, ADI_AXI_REG_VERSION);
 938
 939        if (version >= ADI_AXI_PCORE_VER(4, 3, 'a'))
 940                ret = axi_dmac_read_chan_config(&pdev->dev, dmac);
 941        else
 942                ret = axi_dmac_parse_dt(&pdev->dev, dmac);
 943
 944        if (ret < 0)
 945                goto err_clk_disable;
 946
 947        INIT_LIST_HEAD(&dmac->chan.active_descs);
 948
 949        dma_set_max_seg_size(&pdev->dev, UINT_MAX);
 950
 951        dma_dev = &dmac->dma_dev;
 952        dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
 953        dma_cap_set(DMA_CYCLIC, dma_dev->cap_mask);
 954        dma_cap_set(DMA_INTERLEAVE, dma_dev->cap_mask);
 955        dma_dev->device_free_chan_resources = axi_dmac_free_chan_resources;
 956        dma_dev->device_tx_status = dma_cookie_status;
 957        dma_dev->device_issue_pending = axi_dmac_issue_pending;
 958        dma_dev->device_prep_slave_sg = axi_dmac_prep_slave_sg;
 959        dma_dev->device_prep_dma_cyclic = axi_dmac_prep_dma_cyclic;
 960        dma_dev->device_prep_interleaved_dma = axi_dmac_prep_interleaved;
 961        dma_dev->device_terminate_all = axi_dmac_terminate_all;
 962        dma_dev->device_synchronize = axi_dmac_synchronize;
 963        dma_dev->dev = &pdev->dev;
 964        dma_dev->chancnt = 1;
 965        dma_dev->src_addr_widths = BIT(dmac->chan.src_width);
 966        dma_dev->dst_addr_widths = BIT(dmac->chan.dest_width);
 967        dma_dev->directions = BIT(dmac->chan.direction);
 968        dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
 969        INIT_LIST_HEAD(&dma_dev->channels);
 970
 971        dmac->chan.vchan.desc_free = axi_dmac_desc_free;
 972        vchan_init(&dmac->chan.vchan, dma_dev);
 973
 974        ret = axi_dmac_detect_caps(dmac, version);
 975        if (ret)
 976                goto err_clk_disable;
 977
 978        dma_dev->copy_align = (dmac->chan.address_align_mask + 1);
 979
 980        axi_dmac_write(dmac, AXI_DMAC_REG_IRQ_MASK, 0x00);
 981
 982        ret = dma_async_device_register(dma_dev);
 983        if (ret)
 984                goto err_clk_disable;
 985
 986        ret = of_dma_controller_register(pdev->dev.of_node,
 987                of_dma_xlate_by_chan_id, dma_dev);
 988        if (ret)
 989                goto err_unregister_device;
 990
 991        ret = request_irq(dmac->irq, axi_dmac_interrupt_handler, IRQF_SHARED,
 992                dev_name(&pdev->dev), dmac);
 993        if (ret)
 994                goto err_unregister_of;
 995
 996        platform_set_drvdata(pdev, dmac);
 997
 998        regmap = devm_regmap_init_mmio(&pdev->dev, dmac->base,
 999                 &axi_dmac_regmap_config);
1000        if (IS_ERR(regmap)) {
1001                ret = PTR_ERR(regmap);
1002                goto err_free_irq;
1003        }
1004
1005        return 0;
1006
1007err_free_irq:
1008        free_irq(dmac->irq, dmac);
1009err_unregister_of:
1010        of_dma_controller_free(pdev->dev.of_node);
1011err_unregister_device:
1012        dma_async_device_unregister(&dmac->dma_dev);
1013err_clk_disable:
1014        clk_disable_unprepare(dmac->clk);
1015
1016        return ret;
1017}
1018
1019static int axi_dmac_remove(struct platform_device *pdev)
1020{
1021        struct axi_dmac *dmac = platform_get_drvdata(pdev);
1022
1023        of_dma_controller_free(pdev->dev.of_node);
1024        free_irq(dmac->irq, dmac);
1025        tasklet_kill(&dmac->chan.vchan.task);
1026        dma_async_device_unregister(&dmac->dma_dev);
1027        clk_disable_unprepare(dmac->clk);
1028
1029        return 0;
1030}
1031
1032static const struct of_device_id axi_dmac_of_match_table[] = {
1033        { .compatible = "adi,axi-dmac-1.00.a" },
1034        { },
1035};
1036MODULE_DEVICE_TABLE(of, axi_dmac_of_match_table);
1037
1038static struct platform_driver axi_dmac_driver = {
1039        .driver = {
1040                .name = "dma-axi-dmac",
1041                .of_match_table = axi_dmac_of_match_table,
1042        },
1043        .probe = axi_dmac_probe,
1044        .remove = axi_dmac_remove,
1045};
1046module_platform_driver(axi_dmac_driver);
1047
1048MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
1049MODULE_DESCRIPTION("DMA controller driver for the AXI-DMAC controller");
1050MODULE_LICENSE("GPL v2");
1051