linux/drivers/dma/sun6i-dma.c
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   1/*
   2 * Copyright (C) 2013-2014 Allwinner Tech Co., Ltd
   3 * Author: Sugar <shuge@allwinnertech.com>
   4 *
   5 * Copyright (C) 2014 Maxime Ripard
   6 * Maxime Ripard <maxime.ripard@free-electrons.com>
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License as published by
  10 * the Free Software Foundation; either version 2 of the License, or
  11 * (at your option) any later version.
  12 */
  13
  14#include <linux/clk.h>
  15#include <linux/delay.h>
  16#include <linux/dmaengine.h>
  17#include <linux/dmapool.h>
  18#include <linux/interrupt.h>
  19#include <linux/module.h>
  20#include <linux/of_dma.h>
  21#include <linux/of_device.h>
  22#include <linux/platform_device.h>
  23#include <linux/reset.h>
  24#include <linux/slab.h>
  25#include <linux/types.h>
  26
  27#include "virt-dma.h"
  28
  29/*
  30 * Common registers
  31 */
  32#define DMA_IRQ_EN(x)           ((x) * 0x04)
  33#define DMA_IRQ_HALF                    BIT(0)
  34#define DMA_IRQ_PKG                     BIT(1)
  35#define DMA_IRQ_QUEUE                   BIT(2)
  36
  37#define DMA_IRQ_CHAN_NR                 8
  38#define DMA_IRQ_CHAN_WIDTH              4
  39
  40
  41#define DMA_IRQ_STAT(x)         ((x) * 0x04 + 0x10)
  42
  43#define DMA_STAT                0x30
  44
  45/*
  46 * sun8i specific registers
  47 */
  48#define SUN8I_DMA_GATE          0x20
  49#define SUN8I_DMA_GATE_ENABLE   0x4
  50
  51/*
  52 * Channels specific registers
  53 */
  54#define DMA_CHAN_ENABLE         0x00
  55#define DMA_CHAN_ENABLE_START           BIT(0)
  56#define DMA_CHAN_ENABLE_STOP            0
  57
  58#define DMA_CHAN_PAUSE          0x04
  59#define DMA_CHAN_PAUSE_PAUSE            BIT(1)
  60#define DMA_CHAN_PAUSE_RESUME           0
  61
  62#define DMA_CHAN_LLI_ADDR       0x08
  63
  64#define DMA_CHAN_CUR_CFG        0x0c
  65#define DMA_CHAN_CFG_SRC_DRQ(x)         ((x) & 0x1f)
  66#define DMA_CHAN_CFG_SRC_IO_MODE        BIT(5)
  67#define DMA_CHAN_CFG_SRC_LINEAR_MODE    (0 << 5)
  68#define DMA_CHAN_CFG_SRC_BURST(x)       (((x) & 0x3) << 7)
  69#define DMA_CHAN_CFG_SRC_WIDTH(x)       (((x) & 0x3) << 9)
  70
  71#define DMA_CHAN_CFG_DST_DRQ(x)         (DMA_CHAN_CFG_SRC_DRQ(x) << 16)
  72#define DMA_CHAN_CFG_DST_IO_MODE        (DMA_CHAN_CFG_SRC_IO_MODE << 16)
  73#define DMA_CHAN_CFG_DST_LINEAR_MODE    (DMA_CHAN_CFG_SRC_LINEAR_MODE << 16)
  74#define DMA_CHAN_CFG_DST_BURST(x)       (DMA_CHAN_CFG_SRC_BURST(x) << 16)
  75#define DMA_CHAN_CFG_DST_WIDTH(x)       (DMA_CHAN_CFG_SRC_WIDTH(x) << 16)
  76
  77#define DMA_CHAN_CUR_SRC        0x10
  78
  79#define DMA_CHAN_CUR_DST        0x14
  80
  81#define DMA_CHAN_CUR_CNT        0x18
  82
  83#define DMA_CHAN_CUR_PARA       0x1c
  84
  85
  86/*
  87 * Various hardware related defines
  88 */
  89#define LLI_LAST_ITEM   0xfffff800
  90#define NORMAL_WAIT     8
  91#define DRQ_SDRAM       1
  92
  93/*
  94 * Hardware channels / ports representation
  95 *
  96 * The hardware is used in several SoCs, with differing numbers
  97 * of channels and endpoints. This structure ties those numbers
  98 * to a certain compatible string.
  99 */
 100struct sun6i_dma_config {
 101        u32 nr_max_channels;
 102        u32 nr_max_requests;
 103        u32 nr_max_vchans;
 104};
 105
 106/*
 107 * Hardware representation of the LLI
 108 *
 109 * The hardware will be fed the physical address of this structure,
 110 * and read its content in order to start the transfer.
 111 */
 112struct sun6i_dma_lli {
 113        u32                     cfg;
 114        u32                     src;
 115        u32                     dst;
 116        u32                     len;
 117        u32                     para;
 118        u32                     p_lli_next;
 119
 120        /*
 121         * This field is not used by the DMA controller, but will be
 122         * used by the CPU to go through the list (mostly for dumping
 123         * or freeing it).
 124         */
 125        struct sun6i_dma_lli    *v_lli_next;
 126};
 127
 128
 129struct sun6i_desc {
 130        struct virt_dma_desc    vd;
 131        dma_addr_t              p_lli;
 132        struct sun6i_dma_lli    *v_lli;
 133};
 134
 135struct sun6i_pchan {
 136        u32                     idx;
 137        void __iomem            *base;
 138        struct sun6i_vchan      *vchan;
 139        struct sun6i_desc       *desc;
 140        struct sun6i_desc       *done;
 141};
 142
 143struct sun6i_vchan {
 144        struct virt_dma_chan    vc;
 145        struct list_head        node;
 146        struct dma_slave_config cfg;
 147        struct sun6i_pchan      *phy;
 148        u8                      port;
 149};
 150
 151struct sun6i_dma_dev {
 152        struct dma_device       slave;
 153        void __iomem            *base;
 154        struct clk              *clk;
 155        int                     irq;
 156        spinlock_t              lock;
 157        struct reset_control    *rstc;
 158        struct tasklet_struct   task;
 159        atomic_t                tasklet_shutdown;
 160        struct list_head        pending;
 161        struct dma_pool         *pool;
 162        struct sun6i_pchan      *pchans;
 163        struct sun6i_vchan      *vchans;
 164        const struct sun6i_dma_config *cfg;
 165};
 166
 167static struct device *chan2dev(struct dma_chan *chan)
 168{
 169        return &chan->dev->device;
 170}
 171
 172static inline struct sun6i_dma_dev *to_sun6i_dma_dev(struct dma_device *d)
 173{
 174        return container_of(d, struct sun6i_dma_dev, slave);
 175}
 176
 177static inline struct sun6i_vchan *to_sun6i_vchan(struct dma_chan *chan)
 178{
 179        return container_of(chan, struct sun6i_vchan, vc.chan);
 180}
 181
 182static inline struct sun6i_desc *
 183to_sun6i_desc(struct dma_async_tx_descriptor *tx)
 184{
 185        return container_of(tx, struct sun6i_desc, vd.tx);
 186}
 187
 188static inline void sun6i_dma_dump_com_regs(struct sun6i_dma_dev *sdev)
 189{
 190        dev_dbg(sdev->slave.dev, "Common register:\n"
 191                "\tmask0(%04x): 0x%08x\n"
 192                "\tmask1(%04x): 0x%08x\n"
 193                "\tpend0(%04x): 0x%08x\n"
 194                "\tpend1(%04x): 0x%08x\n"
 195                "\tstats(%04x): 0x%08x\n",
 196                DMA_IRQ_EN(0), readl(sdev->base + DMA_IRQ_EN(0)),
 197                DMA_IRQ_EN(1), readl(sdev->base + DMA_IRQ_EN(1)),
 198                DMA_IRQ_STAT(0), readl(sdev->base + DMA_IRQ_STAT(0)),
 199                DMA_IRQ_STAT(1), readl(sdev->base + DMA_IRQ_STAT(1)),
 200                DMA_STAT, readl(sdev->base + DMA_STAT));
 201}
 202
 203static inline void sun6i_dma_dump_chan_regs(struct sun6i_dma_dev *sdev,
 204                                            struct sun6i_pchan *pchan)
 205{
 206        phys_addr_t reg = virt_to_phys(pchan->base);
 207
 208        dev_dbg(sdev->slave.dev, "Chan %d reg: %pa\n"
 209                "\t___en(%04x): \t0x%08x\n"
 210                "\tpause(%04x): \t0x%08x\n"
 211                "\tstart(%04x): \t0x%08x\n"
 212                "\t__cfg(%04x): \t0x%08x\n"
 213                "\t__src(%04x): \t0x%08x\n"
 214                "\t__dst(%04x): \t0x%08x\n"
 215                "\tcount(%04x): \t0x%08x\n"
 216                "\t_para(%04x): \t0x%08x\n\n",
 217                pchan->idx, &reg,
 218                DMA_CHAN_ENABLE,
 219                readl(pchan->base + DMA_CHAN_ENABLE),
 220                DMA_CHAN_PAUSE,
 221                readl(pchan->base + DMA_CHAN_PAUSE),
 222                DMA_CHAN_LLI_ADDR,
 223                readl(pchan->base + DMA_CHAN_LLI_ADDR),
 224                DMA_CHAN_CUR_CFG,
 225                readl(pchan->base + DMA_CHAN_CUR_CFG),
 226                DMA_CHAN_CUR_SRC,
 227                readl(pchan->base + DMA_CHAN_CUR_SRC),
 228                DMA_CHAN_CUR_DST,
 229                readl(pchan->base + DMA_CHAN_CUR_DST),
 230                DMA_CHAN_CUR_CNT,
 231                readl(pchan->base + DMA_CHAN_CUR_CNT),
 232                DMA_CHAN_CUR_PARA,
 233                readl(pchan->base + DMA_CHAN_CUR_PARA));
 234}
 235
 236static inline s8 convert_burst(u32 maxburst)
 237{
 238        switch (maxburst) {
 239        case 1:
 240                return 0;
 241        case 8:
 242                return 2;
 243        default:
 244                return -EINVAL;
 245        }
 246}
 247
 248static inline s8 convert_buswidth(enum dma_slave_buswidth addr_width)
 249{
 250        if ((addr_width < DMA_SLAVE_BUSWIDTH_1_BYTE) ||
 251            (addr_width > DMA_SLAVE_BUSWIDTH_4_BYTES))
 252                return -EINVAL;
 253
 254        return addr_width >> 1;
 255}
 256
 257static void *sun6i_dma_lli_add(struct sun6i_dma_lli *prev,
 258                               struct sun6i_dma_lli *next,
 259                               dma_addr_t next_phy,
 260                               struct sun6i_desc *txd)
 261{
 262        if ((!prev && !txd) || !next)
 263                return NULL;
 264
 265        if (!prev) {
 266                txd->p_lli = next_phy;
 267                txd->v_lli = next;
 268        } else {
 269                prev->p_lli_next = next_phy;
 270                prev->v_lli_next = next;
 271        }
 272
 273        next->p_lli_next = LLI_LAST_ITEM;
 274        next->v_lli_next = NULL;
 275
 276        return next;
 277}
 278
 279static inline int sun6i_dma_cfg_lli(struct sun6i_dma_lli *lli,
 280                                    dma_addr_t src,
 281                                    dma_addr_t dst, u32 len,
 282                                    struct dma_slave_config *config)
 283{
 284        u8 src_width, dst_width, src_burst, dst_burst;
 285
 286        if (!config)
 287                return -EINVAL;
 288
 289        src_burst = convert_burst(config->src_maxburst);
 290        if (src_burst)
 291                return src_burst;
 292
 293        dst_burst = convert_burst(config->dst_maxburst);
 294        if (dst_burst)
 295                return dst_burst;
 296
 297        src_width = convert_buswidth(config->src_addr_width);
 298        if (src_width)
 299                return src_width;
 300
 301        dst_width = convert_buswidth(config->dst_addr_width);
 302        if (dst_width)
 303                return dst_width;
 304
 305        lli->cfg = DMA_CHAN_CFG_SRC_BURST(src_burst) |
 306                DMA_CHAN_CFG_SRC_WIDTH(src_width) |
 307                DMA_CHAN_CFG_DST_BURST(dst_burst) |
 308                DMA_CHAN_CFG_DST_WIDTH(dst_width);
 309
 310        lli->src = src;
 311        lli->dst = dst;
 312        lli->len = len;
 313        lli->para = NORMAL_WAIT;
 314
 315        return 0;
 316}
 317
 318static inline void sun6i_dma_dump_lli(struct sun6i_vchan *vchan,
 319                                      struct sun6i_dma_lli *lli)
 320{
 321        phys_addr_t p_lli = virt_to_phys(lli);
 322
 323        dev_dbg(chan2dev(&vchan->vc.chan),
 324                "\n\tdesc:   p - %pa v - 0x%p\n"
 325                "\t\tc - 0x%08x s - 0x%08x d - 0x%08x\n"
 326                "\t\tl - 0x%08x p - 0x%08x n - 0x%08x\n",
 327                &p_lli, lli,
 328                lli->cfg, lli->src, lli->dst,
 329                lli->len, lli->para, lli->p_lli_next);
 330}
 331
 332static void sun6i_dma_free_desc(struct virt_dma_desc *vd)
 333{
 334        struct sun6i_desc *txd = to_sun6i_desc(&vd->tx);
 335        struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vd->tx.chan->device);
 336        struct sun6i_dma_lli *v_lli, *v_next;
 337        dma_addr_t p_lli, p_next;
 338
 339        if (unlikely(!txd))
 340                return;
 341
 342        p_lli = txd->p_lli;
 343        v_lli = txd->v_lli;
 344
 345        while (v_lli) {
 346                v_next = v_lli->v_lli_next;
 347                p_next = v_lli->p_lli_next;
 348
 349                dma_pool_free(sdev->pool, v_lli, p_lli);
 350
 351                v_lli = v_next;
 352                p_lli = p_next;
 353        }
 354
 355        kfree(txd);
 356}
 357
 358static int sun6i_dma_start_desc(struct sun6i_vchan *vchan)
 359{
 360        struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vchan->vc.chan.device);
 361        struct virt_dma_desc *desc = vchan_next_desc(&vchan->vc);
 362        struct sun6i_pchan *pchan = vchan->phy;
 363        u32 irq_val, irq_reg, irq_offset;
 364
 365        if (!pchan)
 366                return -EAGAIN;
 367
 368        if (!desc) {
 369                pchan->desc = NULL;
 370                pchan->done = NULL;
 371                return -EAGAIN;
 372        }
 373
 374        list_del(&desc->node);
 375
 376        pchan->desc = to_sun6i_desc(&desc->tx);
 377        pchan->done = NULL;
 378
 379        sun6i_dma_dump_lli(vchan, pchan->desc->v_lli);
 380
 381        irq_reg = pchan->idx / DMA_IRQ_CHAN_NR;
 382        irq_offset = pchan->idx % DMA_IRQ_CHAN_NR;
 383
 384        irq_val = readl(sdev->base + DMA_IRQ_EN(irq_offset));
 385        irq_val |= DMA_IRQ_QUEUE << (irq_offset * DMA_IRQ_CHAN_WIDTH);
 386        writel(irq_val, sdev->base + DMA_IRQ_EN(irq_offset));
 387
 388        writel(pchan->desc->p_lli, pchan->base + DMA_CHAN_LLI_ADDR);
 389        writel(DMA_CHAN_ENABLE_START, pchan->base + DMA_CHAN_ENABLE);
 390
 391        sun6i_dma_dump_com_regs(sdev);
 392        sun6i_dma_dump_chan_regs(sdev, pchan);
 393
 394        return 0;
 395}
 396
 397static void sun6i_dma_tasklet(unsigned long data)
 398{
 399        struct sun6i_dma_dev *sdev = (struct sun6i_dma_dev *)data;
 400        const struct sun6i_dma_config *cfg = sdev->cfg;
 401        struct sun6i_vchan *vchan;
 402        struct sun6i_pchan *pchan;
 403        unsigned int pchan_alloc = 0;
 404        unsigned int pchan_idx;
 405
 406        list_for_each_entry(vchan, &sdev->slave.channels, vc.chan.device_node) {
 407                spin_lock_irq(&vchan->vc.lock);
 408
 409                pchan = vchan->phy;
 410
 411                if (pchan && pchan->done) {
 412                        if (sun6i_dma_start_desc(vchan)) {
 413                                /*
 414                                 * No current txd associated with this channel
 415                                 */
 416                                dev_dbg(sdev->slave.dev, "pchan %u: free\n",
 417                                        pchan->idx);
 418
 419                                /* Mark this channel free */
 420                                vchan->phy = NULL;
 421                                pchan->vchan = NULL;
 422                        }
 423                }
 424                spin_unlock_irq(&vchan->vc.lock);
 425        }
 426
 427        spin_lock_irq(&sdev->lock);
 428        for (pchan_idx = 0; pchan_idx < cfg->nr_max_channels; pchan_idx++) {
 429                pchan = &sdev->pchans[pchan_idx];
 430
 431                if (pchan->vchan || list_empty(&sdev->pending))
 432                        continue;
 433
 434                vchan = list_first_entry(&sdev->pending,
 435                                         struct sun6i_vchan, node);
 436
 437                /* Remove from pending channels */
 438                list_del_init(&vchan->node);
 439                pchan_alloc |= BIT(pchan_idx);
 440
 441                /* Mark this channel allocated */
 442                pchan->vchan = vchan;
 443                vchan->phy = pchan;
 444                dev_dbg(sdev->slave.dev, "pchan %u: alloc vchan %p\n",
 445                        pchan->idx, &vchan->vc);
 446        }
 447        spin_unlock_irq(&sdev->lock);
 448
 449        for (pchan_idx = 0; pchan_idx < cfg->nr_max_channels; pchan_idx++) {
 450                if (!(pchan_alloc & BIT(pchan_idx)))
 451                        continue;
 452
 453                pchan = sdev->pchans + pchan_idx;
 454                vchan = pchan->vchan;
 455                if (vchan) {
 456                        spin_lock_irq(&vchan->vc.lock);
 457                        sun6i_dma_start_desc(vchan);
 458                        spin_unlock_irq(&vchan->vc.lock);
 459                }
 460        }
 461}
 462
 463static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id)
 464{
 465        struct sun6i_dma_dev *sdev = dev_id;
 466        struct sun6i_vchan *vchan;
 467        struct sun6i_pchan *pchan;
 468        int i, j, ret = IRQ_NONE;
 469        u32 status;
 470
 471        for (i = 0; i < sdev->cfg->nr_max_channels / DMA_IRQ_CHAN_NR; i++) {
 472                status = readl(sdev->base + DMA_IRQ_STAT(i));
 473                if (!status)
 474                        continue;
 475
 476                dev_dbg(sdev->slave.dev, "DMA irq status %s: 0x%x\n",
 477                        i ? "high" : "low", status);
 478
 479                writel(status, sdev->base + DMA_IRQ_STAT(i));
 480
 481                for (j = 0; (j < DMA_IRQ_CHAN_NR) && status; j++) {
 482                        if (status & DMA_IRQ_QUEUE) {
 483                                pchan = sdev->pchans + j;
 484                                vchan = pchan->vchan;
 485
 486                                if (vchan) {
 487                                        spin_lock(&vchan->vc.lock);
 488                                        vchan_cookie_complete(&pchan->desc->vd);
 489                                        pchan->done = pchan->desc;
 490                                        spin_unlock(&vchan->vc.lock);
 491                                }
 492                        }
 493
 494                        status = status >> DMA_IRQ_CHAN_WIDTH;
 495                }
 496
 497                if (!atomic_read(&sdev->tasklet_shutdown))
 498                        tasklet_schedule(&sdev->task);
 499                ret = IRQ_HANDLED;
 500        }
 501
 502        return ret;
 503}
 504
 505static struct dma_async_tx_descriptor *sun6i_dma_prep_dma_memcpy(
 506                struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 507                size_t len, unsigned long flags)
 508{
 509        struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
 510        struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 511        struct sun6i_dma_lli *v_lli;
 512        struct sun6i_desc *txd;
 513        dma_addr_t p_lli;
 514        s8 burst, width;
 515
 516        dev_dbg(chan2dev(chan),
 517                "%s; chan: %d, dest: %pad, src: %pad, len: %zu. flags: 0x%08lx\n",
 518                __func__, vchan->vc.chan.chan_id, &dest, &src, len, flags);
 519
 520        if (!len)
 521                return NULL;
 522
 523        txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
 524        if (!txd)
 525                return NULL;
 526
 527        v_lli = dma_pool_alloc(sdev->pool, GFP_NOWAIT, &p_lli);
 528        if (!v_lli) {
 529                dev_err(sdev->slave.dev, "Failed to alloc lli memory\n");
 530                goto err_txd_free;
 531        }
 532
 533        v_lli->src = src;
 534        v_lli->dst = dest;
 535        v_lli->len = len;
 536        v_lli->para = NORMAL_WAIT;
 537
 538        burst = convert_burst(8);
 539        width = convert_buswidth(DMA_SLAVE_BUSWIDTH_4_BYTES);
 540        v_lli->cfg |= DMA_CHAN_CFG_SRC_DRQ(DRQ_SDRAM) |
 541                DMA_CHAN_CFG_DST_DRQ(DRQ_SDRAM) |
 542                DMA_CHAN_CFG_DST_LINEAR_MODE |
 543                DMA_CHAN_CFG_SRC_LINEAR_MODE |
 544                DMA_CHAN_CFG_SRC_BURST(burst) |
 545                DMA_CHAN_CFG_SRC_WIDTH(width) |
 546                DMA_CHAN_CFG_DST_BURST(burst) |
 547                DMA_CHAN_CFG_DST_WIDTH(width);
 548
 549        sun6i_dma_lli_add(NULL, v_lli, p_lli, txd);
 550
 551        sun6i_dma_dump_lli(vchan, v_lli);
 552
 553        return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
 554
 555err_txd_free:
 556        kfree(txd);
 557        return NULL;
 558}
 559
 560static struct dma_async_tx_descriptor *sun6i_dma_prep_slave_sg(
 561                struct dma_chan *chan, struct scatterlist *sgl,
 562                unsigned int sg_len, enum dma_transfer_direction dir,
 563                unsigned long flags, void *context)
 564{
 565        struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
 566        struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 567        struct dma_slave_config *sconfig = &vchan->cfg;
 568        struct sun6i_dma_lli *v_lli, *prev = NULL;
 569        struct sun6i_desc *txd;
 570        struct scatterlist *sg;
 571        dma_addr_t p_lli;
 572        int i, ret;
 573
 574        if (!sgl)
 575                return NULL;
 576
 577        if (!is_slave_direction(dir)) {
 578                dev_err(chan2dev(chan), "Invalid DMA direction\n");
 579                return NULL;
 580        }
 581
 582        txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
 583        if (!txd)
 584                return NULL;
 585
 586        for_each_sg(sgl, sg, sg_len, i) {
 587                v_lli = dma_pool_alloc(sdev->pool, GFP_NOWAIT, &p_lli);
 588                if (!v_lli)
 589                        goto err_lli_free;
 590
 591                if (dir == DMA_MEM_TO_DEV) {
 592                        ret = sun6i_dma_cfg_lli(v_lli, sg_dma_address(sg),
 593                                                sconfig->dst_addr, sg_dma_len(sg),
 594                                                sconfig);
 595                        if (ret)
 596                                goto err_cur_lli_free;
 597
 598                        v_lli->cfg |= DMA_CHAN_CFG_DST_IO_MODE |
 599                                DMA_CHAN_CFG_SRC_LINEAR_MODE |
 600                                DMA_CHAN_CFG_SRC_DRQ(DRQ_SDRAM) |
 601                                DMA_CHAN_CFG_DST_DRQ(vchan->port);
 602
 603                        dev_dbg(chan2dev(chan),
 604                                "%s; chan: %d, dest: %pad, src: %pad, len: %u. flags: 0x%08lx\n",
 605                                __func__, vchan->vc.chan.chan_id,
 606                                &sconfig->dst_addr, &sg_dma_address(sg),
 607                                sg_dma_len(sg), flags);
 608
 609                } else {
 610                        ret = sun6i_dma_cfg_lli(v_lli, sconfig->src_addr,
 611                                                sg_dma_address(sg), sg_dma_len(sg),
 612                                                sconfig);
 613                        if (ret)
 614                                goto err_cur_lli_free;
 615
 616                        v_lli->cfg |= DMA_CHAN_CFG_DST_LINEAR_MODE |
 617                                DMA_CHAN_CFG_SRC_IO_MODE |
 618                                DMA_CHAN_CFG_DST_DRQ(DRQ_SDRAM) |
 619                                DMA_CHAN_CFG_SRC_DRQ(vchan->port);
 620
 621                        dev_dbg(chan2dev(chan),
 622                                "%s; chan: %d, dest: %pad, src: %pad, len: %u. flags: 0x%08lx\n",
 623                                __func__, vchan->vc.chan.chan_id,
 624                                &sg_dma_address(sg), &sconfig->src_addr,
 625                                sg_dma_len(sg), flags);
 626                }
 627
 628                prev = sun6i_dma_lli_add(prev, v_lli, p_lli, txd);
 629        }
 630
 631        dev_dbg(chan2dev(chan), "First: %pad\n", &txd->p_lli);
 632        for (prev = txd->v_lli; prev; prev = prev->v_lli_next)
 633                sun6i_dma_dump_lli(vchan, prev);
 634
 635        return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
 636
 637err_cur_lli_free:
 638        dma_pool_free(sdev->pool, v_lli, p_lli);
 639err_lli_free:
 640        for (prev = txd->v_lli; prev; prev = prev->v_lli_next)
 641                dma_pool_free(sdev->pool, prev, virt_to_phys(prev));
 642        kfree(txd);
 643        return NULL;
 644}
 645
 646static int sun6i_dma_config(struct dma_chan *chan,
 647                            struct dma_slave_config *config)
 648{
 649        struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 650
 651        memcpy(&vchan->cfg, config, sizeof(*config));
 652
 653        return 0;
 654}
 655
 656static int sun6i_dma_pause(struct dma_chan *chan)
 657{
 658        struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
 659        struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 660        struct sun6i_pchan *pchan = vchan->phy;
 661
 662        dev_dbg(chan2dev(chan), "vchan %p: pause\n", &vchan->vc);
 663
 664        if (pchan) {
 665                writel(DMA_CHAN_PAUSE_PAUSE,
 666                       pchan->base + DMA_CHAN_PAUSE);
 667        } else {
 668                spin_lock(&sdev->lock);
 669                list_del_init(&vchan->node);
 670                spin_unlock(&sdev->lock);
 671        }
 672
 673        return 0;
 674}
 675
 676static int sun6i_dma_resume(struct dma_chan *chan)
 677{
 678        struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
 679        struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 680        struct sun6i_pchan *pchan = vchan->phy;
 681        unsigned long flags;
 682
 683        dev_dbg(chan2dev(chan), "vchan %p: resume\n", &vchan->vc);
 684
 685        spin_lock_irqsave(&vchan->vc.lock, flags);
 686
 687        if (pchan) {
 688                writel(DMA_CHAN_PAUSE_RESUME,
 689                       pchan->base + DMA_CHAN_PAUSE);
 690        } else if (!list_empty(&vchan->vc.desc_issued)) {
 691                spin_lock(&sdev->lock);
 692                list_add_tail(&vchan->node, &sdev->pending);
 693                spin_unlock(&sdev->lock);
 694        }
 695
 696        spin_unlock_irqrestore(&vchan->vc.lock, flags);
 697
 698        return 0;
 699}
 700
 701static int sun6i_dma_terminate_all(struct dma_chan *chan)
 702{
 703        struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
 704        struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 705        struct sun6i_pchan *pchan = vchan->phy;
 706        unsigned long flags;
 707        LIST_HEAD(head);
 708
 709        spin_lock(&sdev->lock);
 710        list_del_init(&vchan->node);
 711        spin_unlock(&sdev->lock);
 712
 713        spin_lock_irqsave(&vchan->vc.lock, flags);
 714
 715        vchan_get_all_descriptors(&vchan->vc, &head);
 716
 717        if (pchan) {
 718                writel(DMA_CHAN_ENABLE_STOP, pchan->base + DMA_CHAN_ENABLE);
 719                writel(DMA_CHAN_PAUSE_RESUME, pchan->base + DMA_CHAN_PAUSE);
 720
 721                vchan->phy = NULL;
 722                pchan->vchan = NULL;
 723                pchan->desc = NULL;
 724                pchan->done = NULL;
 725        }
 726
 727        spin_unlock_irqrestore(&vchan->vc.lock, flags);
 728
 729        vchan_dma_desc_free_list(&vchan->vc, &head);
 730
 731        return 0;
 732}
 733
 734static enum dma_status sun6i_dma_tx_status(struct dma_chan *chan,
 735                                           dma_cookie_t cookie,
 736                                           struct dma_tx_state *state)
 737{
 738        struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 739        struct sun6i_pchan *pchan = vchan->phy;
 740        struct sun6i_dma_lli *lli;
 741        struct virt_dma_desc *vd;
 742        struct sun6i_desc *txd;
 743        enum dma_status ret;
 744        unsigned long flags;
 745        size_t bytes = 0;
 746
 747        ret = dma_cookie_status(chan, cookie, state);
 748        if (ret == DMA_COMPLETE)
 749                return ret;
 750
 751        spin_lock_irqsave(&vchan->vc.lock, flags);
 752
 753        vd = vchan_find_desc(&vchan->vc, cookie);
 754        txd = to_sun6i_desc(&vd->tx);
 755
 756        if (vd) {
 757                for (lli = txd->v_lli; lli != NULL; lli = lli->v_lli_next)
 758                        bytes += lli->len;
 759        } else if (!pchan || !pchan->desc) {
 760                bytes = 0;
 761        } else {
 762                bytes = readl(pchan->base + DMA_CHAN_CUR_CNT);
 763        }
 764
 765        spin_unlock_irqrestore(&vchan->vc.lock, flags);
 766
 767        dma_set_residue(state, bytes);
 768
 769        return ret;
 770}
 771
 772static void sun6i_dma_issue_pending(struct dma_chan *chan)
 773{
 774        struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
 775        struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 776        unsigned long flags;
 777
 778        spin_lock_irqsave(&vchan->vc.lock, flags);
 779
 780        if (vchan_issue_pending(&vchan->vc)) {
 781                spin_lock(&sdev->lock);
 782
 783                if (!vchan->phy && list_empty(&vchan->node)) {
 784                        list_add_tail(&vchan->node, &sdev->pending);
 785                        tasklet_schedule(&sdev->task);
 786                        dev_dbg(chan2dev(chan), "vchan %p: issued\n",
 787                                &vchan->vc);
 788                }
 789
 790                spin_unlock(&sdev->lock);
 791        } else {
 792                dev_dbg(chan2dev(chan), "vchan %p: nothing to issue\n",
 793                        &vchan->vc);
 794        }
 795
 796        spin_unlock_irqrestore(&vchan->vc.lock, flags);
 797}
 798
 799static void sun6i_dma_free_chan_resources(struct dma_chan *chan)
 800{
 801        struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
 802        struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 803        unsigned long flags;
 804
 805        spin_lock_irqsave(&sdev->lock, flags);
 806        list_del_init(&vchan->node);
 807        spin_unlock_irqrestore(&sdev->lock, flags);
 808
 809        vchan_free_chan_resources(&vchan->vc);
 810}
 811
 812static struct dma_chan *sun6i_dma_of_xlate(struct of_phandle_args *dma_spec,
 813                                           struct of_dma *ofdma)
 814{
 815        struct sun6i_dma_dev *sdev = ofdma->of_dma_data;
 816        struct sun6i_vchan *vchan;
 817        struct dma_chan *chan;
 818        u8 port = dma_spec->args[0];
 819
 820        if (port > sdev->cfg->nr_max_requests)
 821                return NULL;
 822
 823        chan = dma_get_any_slave_channel(&sdev->slave);
 824        if (!chan)
 825                return NULL;
 826
 827        vchan = to_sun6i_vchan(chan);
 828        vchan->port = port;
 829
 830        return chan;
 831}
 832
 833static inline void sun6i_kill_tasklet(struct sun6i_dma_dev *sdev)
 834{
 835        /* Disable all interrupts from DMA */
 836        writel(0, sdev->base + DMA_IRQ_EN(0));
 837        writel(0, sdev->base + DMA_IRQ_EN(1));
 838
 839        /* Prevent spurious interrupts from scheduling the tasklet */
 840        atomic_inc(&sdev->tasklet_shutdown);
 841
 842        /* Make sure we won't have any further interrupts */
 843        devm_free_irq(sdev->slave.dev, sdev->irq, sdev);
 844
 845        /* Actually prevent the tasklet from being scheduled */
 846        tasklet_kill(&sdev->task);
 847}
 848
 849static inline void sun6i_dma_free(struct sun6i_dma_dev *sdev)
 850{
 851        int i;
 852
 853        for (i = 0; i < sdev->cfg->nr_max_vchans; i++) {
 854                struct sun6i_vchan *vchan = &sdev->vchans[i];
 855
 856                list_del(&vchan->vc.chan.device_node);
 857                tasklet_kill(&vchan->vc.task);
 858        }
 859}
 860
 861/*
 862 * For A31:
 863 *
 864 * There's 16 physical channels that can work in parallel.
 865 *
 866 * However we have 30 different endpoints for our requests.
 867 *
 868 * Since the channels are able to handle only an unidirectional
 869 * transfer, we need to allocate more virtual channels so that
 870 * everyone can grab one channel.
 871 *
 872 * Some devices can't work in both direction (mostly because it
 873 * wouldn't make sense), so we have a bit fewer virtual channels than
 874 * 2 channels per endpoints.
 875 */
 876
 877static struct sun6i_dma_config sun6i_a31_dma_cfg = {
 878        .nr_max_channels = 16,
 879        .nr_max_requests = 30,
 880        .nr_max_vchans   = 53,
 881};
 882
 883/*
 884 * The A23 only has 8 physical channels, a maximum DRQ port id of 24,
 885 * and a total of 37 usable source and destination endpoints.
 886 */
 887
 888static struct sun6i_dma_config sun8i_a23_dma_cfg = {
 889        .nr_max_channels = 8,
 890        .nr_max_requests = 24,
 891        .nr_max_vchans   = 37,
 892};
 893
 894static const struct of_device_id sun6i_dma_match[] = {
 895        { .compatible = "allwinner,sun6i-a31-dma", .data = &sun6i_a31_dma_cfg },
 896        { .compatible = "allwinner,sun8i-a23-dma", .data = &sun8i_a23_dma_cfg },
 897        { /* sentinel */ }
 898};
 899
 900static int sun6i_dma_probe(struct platform_device *pdev)
 901{
 902        const struct of_device_id *device;
 903        struct sun6i_dma_dev *sdc;
 904        struct resource *res;
 905        int ret, i;
 906
 907        sdc = devm_kzalloc(&pdev->dev, sizeof(*sdc), GFP_KERNEL);
 908        if (!sdc)
 909                return -ENOMEM;
 910
 911        device = of_match_device(sun6i_dma_match, &pdev->dev);
 912        if (!device)
 913                return -ENODEV;
 914        sdc->cfg = device->data;
 915
 916        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 917        sdc->base = devm_ioremap_resource(&pdev->dev, res);
 918        if (IS_ERR(sdc->base))
 919                return PTR_ERR(sdc->base);
 920
 921        sdc->irq = platform_get_irq(pdev, 0);
 922        if (sdc->irq < 0) {
 923                dev_err(&pdev->dev, "Cannot claim IRQ\n");
 924                return sdc->irq;
 925        }
 926
 927        sdc->clk = devm_clk_get(&pdev->dev, NULL);
 928        if (IS_ERR(sdc->clk)) {
 929                dev_err(&pdev->dev, "No clock specified\n");
 930                return PTR_ERR(sdc->clk);
 931        }
 932
 933        sdc->rstc = devm_reset_control_get(&pdev->dev, NULL);
 934        if (IS_ERR(sdc->rstc)) {
 935                dev_err(&pdev->dev, "No reset controller specified\n");
 936                return PTR_ERR(sdc->rstc);
 937        }
 938
 939        sdc->pool = dmam_pool_create(dev_name(&pdev->dev), &pdev->dev,
 940                                     sizeof(struct sun6i_dma_lli), 4, 0);
 941        if (!sdc->pool) {
 942                dev_err(&pdev->dev, "No memory for descriptors dma pool\n");
 943                return -ENOMEM;
 944        }
 945
 946        platform_set_drvdata(pdev, sdc);
 947        INIT_LIST_HEAD(&sdc->pending);
 948        spin_lock_init(&sdc->lock);
 949
 950        dma_cap_set(DMA_PRIVATE, sdc->slave.cap_mask);
 951        dma_cap_set(DMA_MEMCPY, sdc->slave.cap_mask);
 952        dma_cap_set(DMA_SLAVE, sdc->slave.cap_mask);
 953
 954        INIT_LIST_HEAD(&sdc->slave.channels);
 955        sdc->slave.device_free_chan_resources   = sun6i_dma_free_chan_resources;
 956        sdc->slave.device_tx_status             = sun6i_dma_tx_status;
 957        sdc->slave.device_issue_pending         = sun6i_dma_issue_pending;
 958        sdc->slave.device_prep_slave_sg         = sun6i_dma_prep_slave_sg;
 959        sdc->slave.device_prep_dma_memcpy       = sun6i_dma_prep_dma_memcpy;
 960        sdc->slave.copy_align                   = 4;
 961        sdc->slave.device_config                = sun6i_dma_config;
 962        sdc->slave.device_pause                 = sun6i_dma_pause;
 963        sdc->slave.device_resume                = sun6i_dma_resume;
 964        sdc->slave.device_terminate_all         = sun6i_dma_terminate_all;
 965        sdc->slave.src_addr_widths              = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
 966                                                  BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
 967                                                  BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
 968        sdc->slave.dst_addr_widths              = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
 969                                                  BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
 970                                                  BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
 971        sdc->slave.directions                   = BIT(DMA_DEV_TO_MEM) |
 972                                                  BIT(DMA_MEM_TO_DEV);
 973        sdc->slave.residue_granularity          = DMA_RESIDUE_GRANULARITY_BURST;
 974        sdc->slave.dev = &pdev->dev;
 975
 976        sdc->pchans = devm_kcalloc(&pdev->dev, sdc->cfg->nr_max_channels,
 977                                   sizeof(struct sun6i_pchan), GFP_KERNEL);
 978        if (!sdc->pchans)
 979                return -ENOMEM;
 980
 981        sdc->vchans = devm_kcalloc(&pdev->dev, sdc->cfg->nr_max_vchans,
 982                                   sizeof(struct sun6i_vchan), GFP_KERNEL);
 983        if (!sdc->vchans)
 984                return -ENOMEM;
 985
 986        tasklet_init(&sdc->task, sun6i_dma_tasklet, (unsigned long)sdc);
 987
 988        for (i = 0; i < sdc->cfg->nr_max_channels; i++) {
 989                struct sun6i_pchan *pchan = &sdc->pchans[i];
 990
 991                pchan->idx = i;
 992                pchan->base = sdc->base + 0x100 + i * 0x40;
 993        }
 994
 995        for (i = 0; i < sdc->cfg->nr_max_vchans; i++) {
 996                struct sun6i_vchan *vchan = &sdc->vchans[i];
 997
 998                INIT_LIST_HEAD(&vchan->node);
 999                vchan->vc.desc_free = sun6i_dma_free_desc;
1000                vchan_init(&vchan->vc, &sdc->slave);
1001        }
1002
1003        ret = reset_control_deassert(sdc->rstc);
1004        if (ret) {
1005                dev_err(&pdev->dev, "Couldn't deassert the device from reset\n");
1006                goto err_chan_free;
1007        }
1008
1009        ret = clk_prepare_enable(sdc->clk);
1010        if (ret) {
1011                dev_err(&pdev->dev, "Couldn't enable the clock\n");
1012                goto err_reset_assert;
1013        }
1014
1015        ret = devm_request_irq(&pdev->dev, sdc->irq, sun6i_dma_interrupt, 0,
1016                               dev_name(&pdev->dev), sdc);
1017        if (ret) {
1018                dev_err(&pdev->dev, "Cannot request IRQ\n");
1019                goto err_clk_disable;
1020        }
1021
1022        ret = dma_async_device_register(&sdc->slave);
1023        if (ret) {
1024                dev_warn(&pdev->dev, "Failed to register DMA engine device\n");
1025                goto err_irq_disable;
1026        }
1027
1028        ret = of_dma_controller_register(pdev->dev.of_node, sun6i_dma_of_xlate,
1029                                         sdc);
1030        if (ret) {
1031                dev_err(&pdev->dev, "of_dma_controller_register failed\n");
1032                goto err_dma_unregister;
1033        }
1034
1035        /*
1036         * sun8i variant requires us to toggle a dma gating register,
1037         * as seen in Allwinner's SDK. This register is not documented
1038         * in the A23 user manual.
1039         */
1040        if (of_device_is_compatible(pdev->dev.of_node,
1041                                    "allwinner,sun8i-a23-dma"))
1042                writel(SUN8I_DMA_GATE_ENABLE, sdc->base + SUN8I_DMA_GATE);
1043
1044        return 0;
1045
1046err_dma_unregister:
1047        dma_async_device_unregister(&sdc->slave);
1048err_irq_disable:
1049        sun6i_kill_tasklet(sdc);
1050err_clk_disable:
1051        clk_disable_unprepare(sdc->clk);
1052err_reset_assert:
1053        reset_control_assert(sdc->rstc);
1054err_chan_free:
1055        sun6i_dma_free(sdc);
1056        return ret;
1057}
1058
1059static int sun6i_dma_remove(struct platform_device *pdev)
1060{
1061        struct sun6i_dma_dev *sdc = platform_get_drvdata(pdev);
1062
1063        of_dma_controller_free(pdev->dev.of_node);
1064        dma_async_device_unregister(&sdc->slave);
1065
1066        sun6i_kill_tasklet(sdc);
1067
1068        clk_disable_unprepare(sdc->clk);
1069        reset_control_assert(sdc->rstc);
1070
1071        sun6i_dma_free(sdc);
1072
1073        return 0;
1074}
1075
1076static struct platform_driver sun6i_dma_driver = {
1077        .probe          = sun6i_dma_probe,
1078        .remove         = sun6i_dma_remove,
1079        .driver = {
1080                .name           = "sun6i-dma",
1081                .of_match_table = sun6i_dma_match,
1082        },
1083};
1084module_platform_driver(sun6i_dma_driver);
1085
1086MODULE_DESCRIPTION("Allwinner A31 DMA Controller Driver");
1087MODULE_AUTHOR("Sugar <shuge@allwinnertech.com>");
1088MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
1089MODULE_LICENSE("GPL");
1090