linux/drivers/dma/owl-dma.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2//
   3// Actions Semi Owl SoCs DMA driver
   4//
   5// Copyright (c) 2014 Actions Semi Inc.
   6// Author: David Liu <liuwei@actions-semi.com>
   7//
   8// Copyright (c) 2018 Linaro Ltd.
   9// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
  10
  11#include <linux/bitops.h>
  12#include <linux/clk.h>
  13#include <linux/delay.h>
  14#include <linux/dmaengine.h>
  15#include <linux/dma-mapping.h>
  16#include <linux/dmapool.h>
  17#include <linux/err.h>
  18#include <linux/init.h>
  19#include <linux/interrupt.h>
  20#include <linux/io.h>
  21#include <linux/mm.h>
  22#include <linux/module.h>
  23#include <linux/of_device.h>
  24#include <linux/of_dma.h>
  25#include <linux/slab.h>
  26#include "virt-dma.h"
  27
  28#define OWL_DMA_FRAME_MAX_LENGTH                0xfffff
  29
  30/* Global DMA Controller Registers */
  31#define OWL_DMA_IRQ_PD0                         0x00
  32#define OWL_DMA_IRQ_PD1                         0x04
  33#define OWL_DMA_IRQ_PD2                         0x08
  34#define OWL_DMA_IRQ_PD3                         0x0C
  35#define OWL_DMA_IRQ_EN0                         0x10
  36#define OWL_DMA_IRQ_EN1                         0x14
  37#define OWL_DMA_IRQ_EN2                         0x18
  38#define OWL_DMA_IRQ_EN3                         0x1C
  39#define OWL_DMA_SECURE_ACCESS_CTL               0x20
  40#define OWL_DMA_NIC_QOS                         0x24
  41#define OWL_DMA_DBGSEL                          0x28
  42#define OWL_DMA_IDLE_STAT                       0x2C
  43
  44/* Channel Registers */
  45#define OWL_DMA_CHAN_BASE(i)                    (0x100 + (i) * 0x100)
  46#define OWL_DMAX_MODE                           0x00
  47#define OWL_DMAX_SOURCE                         0x04
  48#define OWL_DMAX_DESTINATION                    0x08
  49#define OWL_DMAX_FRAME_LEN                      0x0C
  50#define OWL_DMAX_FRAME_CNT                      0x10
  51#define OWL_DMAX_REMAIN_FRAME_CNT               0x14
  52#define OWL_DMAX_REMAIN_CNT                     0x18
  53#define OWL_DMAX_SOURCE_STRIDE                  0x1C
  54#define OWL_DMAX_DESTINATION_STRIDE             0x20
  55#define OWL_DMAX_START                          0x24
  56#define OWL_DMAX_PAUSE                          0x28
  57#define OWL_DMAX_CHAINED_CTL                    0x2C
  58#define OWL_DMAX_CONSTANT                       0x30
  59#define OWL_DMAX_LINKLIST_CTL                   0x34
  60#define OWL_DMAX_NEXT_DESCRIPTOR                0x38
  61#define OWL_DMAX_CURRENT_DESCRIPTOR_NUM         0x3C
  62#define OWL_DMAX_INT_CTL                        0x40
  63#define OWL_DMAX_INT_STATUS                     0x44
  64#define OWL_DMAX_CURRENT_SOURCE_POINTER         0x48
  65#define OWL_DMAX_CURRENT_DESTINATION_POINTER    0x4C
  66
  67/* OWL_DMAX_MODE Bits */
  68#define OWL_DMA_MODE_TS(x)                      (((x) & GENMASK(5, 0)) << 0)
  69#define OWL_DMA_MODE_ST(x)                      (((x) & GENMASK(1, 0)) << 8)
  70#define OWL_DMA_MODE_ST_DEV                     OWL_DMA_MODE_ST(0)
  71#define OWL_DMA_MODE_ST_DCU                     OWL_DMA_MODE_ST(2)
  72#define OWL_DMA_MODE_ST_SRAM                    OWL_DMA_MODE_ST(3)
  73#define OWL_DMA_MODE_DT(x)                      (((x) & GENMASK(1, 0)) << 10)
  74#define OWL_DMA_MODE_DT_DEV                     OWL_DMA_MODE_DT(0)
  75#define OWL_DMA_MODE_DT_DCU                     OWL_DMA_MODE_DT(2)
  76#define OWL_DMA_MODE_DT_SRAM                    OWL_DMA_MODE_DT(3)
  77#define OWL_DMA_MODE_SAM(x)                     (((x) & GENMASK(1, 0)) << 16)
  78#define OWL_DMA_MODE_SAM_CONST                  OWL_DMA_MODE_SAM(0)
  79#define OWL_DMA_MODE_SAM_INC                    OWL_DMA_MODE_SAM(1)
  80#define OWL_DMA_MODE_SAM_STRIDE                 OWL_DMA_MODE_SAM(2)
  81#define OWL_DMA_MODE_DAM(x)                     (((x) & GENMASK(1, 0)) << 18)
  82#define OWL_DMA_MODE_DAM_CONST                  OWL_DMA_MODE_DAM(0)
  83#define OWL_DMA_MODE_DAM_INC                    OWL_DMA_MODE_DAM(1)
  84#define OWL_DMA_MODE_DAM_STRIDE                 OWL_DMA_MODE_DAM(2)
  85#define OWL_DMA_MODE_PW(x)                      (((x) & GENMASK(2, 0)) << 20)
  86#define OWL_DMA_MODE_CB                         BIT(23)
  87#define OWL_DMA_MODE_NDDBW(x)                   (((x) & 0x1) << 28)
  88#define OWL_DMA_MODE_NDDBW_32BIT                OWL_DMA_MODE_NDDBW(0)
  89#define OWL_DMA_MODE_NDDBW_8BIT                 OWL_DMA_MODE_NDDBW(1)
  90#define OWL_DMA_MODE_CFE                        BIT(29)
  91#define OWL_DMA_MODE_LME                        BIT(30)
  92#define OWL_DMA_MODE_CME                        BIT(31)
  93
  94/* OWL_DMAX_LINKLIST_CTL Bits */
  95#define OWL_DMA_LLC_SAV(x)                      (((x) & GENMASK(1, 0)) << 8)
  96#define OWL_DMA_LLC_SAV_INC                     OWL_DMA_LLC_SAV(0)
  97#define OWL_DMA_LLC_SAV_LOAD_NEXT               OWL_DMA_LLC_SAV(1)
  98#define OWL_DMA_LLC_SAV_LOAD_PREV               OWL_DMA_LLC_SAV(2)
  99#define OWL_DMA_LLC_DAV(x)                      (((x) & GENMASK(1, 0)) << 10)
 100#define OWL_DMA_LLC_DAV_INC                     OWL_DMA_LLC_DAV(0)
 101#define OWL_DMA_LLC_DAV_LOAD_NEXT               OWL_DMA_LLC_DAV(1)
 102#define OWL_DMA_LLC_DAV_LOAD_PREV               OWL_DMA_LLC_DAV(2)
 103#define OWL_DMA_LLC_SUSPEND                     BIT(16)
 104
 105/* OWL_DMAX_INT_CTL Bits */
 106#define OWL_DMA_INTCTL_BLOCK                    BIT(0)
 107#define OWL_DMA_INTCTL_SUPER_BLOCK              BIT(1)
 108#define OWL_DMA_INTCTL_FRAME                    BIT(2)
 109#define OWL_DMA_INTCTL_HALF_FRAME               BIT(3)
 110#define OWL_DMA_INTCTL_LAST_FRAME               BIT(4)
 111
 112/* OWL_DMAX_INT_STATUS Bits */
 113#define OWL_DMA_INTSTAT_BLOCK                   BIT(0)
 114#define OWL_DMA_INTSTAT_SUPER_BLOCK             BIT(1)
 115#define OWL_DMA_INTSTAT_FRAME                   BIT(2)
 116#define OWL_DMA_INTSTAT_HALF_FRAME              BIT(3)
 117#define OWL_DMA_INTSTAT_LAST_FRAME              BIT(4)
 118
 119/* Pack shift and newshift in a single word */
 120#define BIT_FIELD(val, width, shift, newshift)  \
 121                ((((val) >> (shift)) & ((BIT(width)) - 1)) << (newshift))
 122
 123/* Frame count value is fixed as 1 */
 124#define FCNT_VAL                                0x1
 125
 126/**
 127 * enum owl_dmadesc_offsets - Describe DMA descriptor, hardware link
 128 * list for dma transfer
 129 * @OWL_DMADESC_NEXT_LLI: physical address of the next link list
 130 * @OWL_DMADESC_SADDR: source physical address
 131 * @OWL_DMADESC_DADDR: destination physical address
 132 * @OWL_DMADESC_FLEN: frame length
 133 * @OWL_DMADESC_SRC_STRIDE: source stride
 134 * @OWL_DMADESC_DST_STRIDE: destination stride
 135 * @OWL_DMADESC_CTRLA: dma_mode and linklist ctrl config
 136 * @OWL_DMADESC_CTRLB: interrupt config
 137 * @OWL_DMADESC_CONST_NUM: data for constant fill
 138 * @OWL_DMADESC_SIZE: max size of this enum
 139 */
 140enum owl_dmadesc_offsets {
 141        OWL_DMADESC_NEXT_LLI = 0,
 142        OWL_DMADESC_SADDR,
 143        OWL_DMADESC_DADDR,
 144        OWL_DMADESC_FLEN,
 145        OWL_DMADESC_SRC_STRIDE,
 146        OWL_DMADESC_DST_STRIDE,
 147        OWL_DMADESC_CTRLA,
 148        OWL_DMADESC_CTRLB,
 149        OWL_DMADESC_CONST_NUM,
 150        OWL_DMADESC_SIZE
 151};
 152
 153enum owl_dma_id {
 154        S900_DMA,
 155        S700_DMA,
 156};
 157
 158/**
 159 * struct owl_dma_lli - Link list for dma transfer
 160 * @hw: hardware link list
 161 * @phys: physical address of hardware link list
 162 * @node: node for txd's lli_list
 163 */
 164struct owl_dma_lli {
 165        u32                     hw[OWL_DMADESC_SIZE];
 166        dma_addr_t              phys;
 167        struct list_head        node;
 168};
 169
 170/**
 171 * struct owl_dma_txd - Wrapper for struct dma_async_tx_descriptor
 172 * @vd: virtual DMA descriptor
 173 * @lli_list: link list of lli nodes
 174 * @cyclic: flag to indicate cyclic transfers
 175 */
 176struct owl_dma_txd {
 177        struct virt_dma_desc    vd;
 178        struct list_head        lli_list;
 179        bool                    cyclic;
 180};
 181
 182/**
 183 * struct owl_dma_pchan - Holder for the physical channels
 184 * @id: physical index to this channel
 185 * @base: virtual memory base for the dma channel
 186 * @vchan: the virtual channel currently being served by this physical channel
 187 */
 188struct owl_dma_pchan {
 189        u32                     id;
 190        void __iomem            *base;
 191        struct owl_dma_vchan    *vchan;
 192};
 193
 194/**
 195 * struct owl_dma_pchan - Wrapper for DMA ENGINE channel
 196 * @vc: wrappped virtual channel
 197 * @pchan: the physical channel utilized by this channel
 198 * @txd: active transaction on this channel
 199 * @cfg: slave configuration for this channel
 200 * @drq: physical DMA request ID for this channel
 201 */
 202struct owl_dma_vchan {
 203        struct virt_dma_chan    vc;
 204        struct owl_dma_pchan    *pchan;
 205        struct owl_dma_txd      *txd;
 206        struct dma_slave_config cfg;
 207        u8                      drq;
 208};
 209
 210/**
 211 * struct owl_dma - Holder for the Owl DMA controller
 212 * @dma: dma engine for this instance
 213 * @base: virtual memory base for the DMA controller
 214 * @clk: clock for the DMA controller
 215 * @lock: a lock to use when change DMA controller global register
 216 * @lli_pool: a pool for the LLI descriptors
 217 * @irq: interrupt ID for the DMA controller
 218 * @nr_pchans: the number of physical channels
 219 * @pchans: array of data for the physical channels
 220 * @nr_vchans: the number of physical channels
 221 * @vchans: array of data for the physical channels
 222 * @devid: device id based on OWL SoC
 223 */
 224struct owl_dma {
 225        struct dma_device       dma;
 226        void __iomem            *base;
 227        struct clk              *clk;
 228        spinlock_t              lock;
 229        struct dma_pool         *lli_pool;
 230        int                     irq;
 231
 232        unsigned int            nr_pchans;
 233        struct owl_dma_pchan    *pchans;
 234
 235        unsigned int            nr_vchans;
 236        struct owl_dma_vchan    *vchans;
 237        enum owl_dma_id         devid;
 238};
 239
 240static void pchan_update(struct owl_dma_pchan *pchan, u32 reg,
 241                         u32 val, bool state)
 242{
 243        u32 regval;
 244
 245        regval = readl(pchan->base + reg);
 246
 247        if (state)
 248                regval |= val;
 249        else
 250                regval &= ~val;
 251
 252        writel(val, pchan->base + reg);
 253}
 254
 255static void pchan_writel(struct owl_dma_pchan *pchan, u32 reg, u32 data)
 256{
 257        writel(data, pchan->base + reg);
 258}
 259
 260static u32 pchan_readl(struct owl_dma_pchan *pchan, u32 reg)
 261{
 262        return readl(pchan->base + reg);
 263}
 264
 265static void dma_update(struct owl_dma *od, u32 reg, u32 val, bool state)
 266{
 267        u32 regval;
 268
 269        regval = readl(od->base + reg);
 270
 271        if (state)
 272                regval |= val;
 273        else
 274                regval &= ~val;
 275
 276        writel(val, od->base + reg);
 277}
 278
 279static void dma_writel(struct owl_dma *od, u32 reg, u32 data)
 280{
 281        writel(data, od->base + reg);
 282}
 283
 284static u32 dma_readl(struct owl_dma *od, u32 reg)
 285{
 286        return readl(od->base + reg);
 287}
 288
 289static inline struct owl_dma *to_owl_dma(struct dma_device *dd)
 290{
 291        return container_of(dd, struct owl_dma, dma);
 292}
 293
 294static struct device *chan2dev(struct dma_chan *chan)
 295{
 296        return &chan->dev->device;
 297}
 298
 299static inline struct owl_dma_vchan *to_owl_vchan(struct dma_chan *chan)
 300{
 301        return container_of(chan, struct owl_dma_vchan, vc.chan);
 302}
 303
 304static inline struct owl_dma_txd *to_owl_txd(struct dma_async_tx_descriptor *tx)
 305{
 306        return container_of(tx, struct owl_dma_txd, vd.tx);
 307}
 308
 309static inline u32 llc_hw_ctrla(u32 mode, u32 llc_ctl)
 310{
 311        u32 ctl;
 312
 313        ctl = BIT_FIELD(mode, 4, 28, 28) |
 314              BIT_FIELD(mode, 8, 16, 20) |
 315              BIT_FIELD(mode, 4, 8, 16) |
 316              BIT_FIELD(mode, 6, 0, 10) |
 317              BIT_FIELD(llc_ctl, 2, 10, 8) |
 318              BIT_FIELD(llc_ctl, 2, 8, 6);
 319
 320        return ctl;
 321}
 322
 323static inline u32 llc_hw_ctrlb(u32 int_ctl)
 324{
 325        u32 ctl;
 326
 327        /*
 328         * Irrespective of the SoC, ctrlb value starts filling from
 329         * bit 18.
 330         */
 331        ctl = BIT_FIELD(int_ctl, 7, 0, 18);
 332
 333        return ctl;
 334}
 335
 336static u32 llc_hw_flen(struct owl_dma_lli *lli)
 337{
 338        return lli->hw[OWL_DMADESC_FLEN] & GENMASK(19, 0);
 339}
 340
 341static void owl_dma_free_lli(struct owl_dma *od,
 342                             struct owl_dma_lli *lli)
 343{
 344        list_del(&lli->node);
 345        dma_pool_free(od->lli_pool, lli, lli->phys);
 346}
 347
 348static struct owl_dma_lli *owl_dma_alloc_lli(struct owl_dma *od)
 349{
 350        struct owl_dma_lli *lli;
 351        dma_addr_t phys;
 352
 353        lli = dma_pool_alloc(od->lli_pool, GFP_NOWAIT, &phys);
 354        if (!lli)
 355                return NULL;
 356
 357        INIT_LIST_HEAD(&lli->node);
 358        lli->phys = phys;
 359
 360        return lli;
 361}
 362
 363static struct owl_dma_lli *owl_dma_add_lli(struct owl_dma_txd *txd,
 364                                           struct owl_dma_lli *prev,
 365                                           struct owl_dma_lli *next,
 366                                           bool is_cyclic)
 367{
 368        if (!is_cyclic)
 369                list_add_tail(&next->node, &txd->lli_list);
 370
 371        if (prev) {
 372                prev->hw[OWL_DMADESC_NEXT_LLI] = next->phys;
 373                prev->hw[OWL_DMADESC_CTRLA] |=
 374                                        llc_hw_ctrla(OWL_DMA_MODE_LME, 0);
 375        }
 376
 377        return next;
 378}
 379
 380static inline int owl_dma_cfg_lli(struct owl_dma_vchan *vchan,
 381                                  struct owl_dma_lli *lli,
 382                                  dma_addr_t src, dma_addr_t dst,
 383                                  u32 len, enum dma_transfer_direction dir,
 384                                  struct dma_slave_config *sconfig,
 385                                  bool is_cyclic)
 386{
 387        struct owl_dma *od = to_owl_dma(vchan->vc.chan.device);
 388        u32 mode, ctrlb;
 389
 390        mode = OWL_DMA_MODE_PW(0);
 391
 392        switch (dir) {
 393        case DMA_MEM_TO_MEM:
 394                mode |= OWL_DMA_MODE_TS(0) | OWL_DMA_MODE_ST_DCU |
 395                        OWL_DMA_MODE_DT_DCU | OWL_DMA_MODE_SAM_INC |
 396                        OWL_DMA_MODE_DAM_INC;
 397
 398                break;
 399        case DMA_MEM_TO_DEV:
 400                mode |= OWL_DMA_MODE_TS(vchan->drq)
 401                        | OWL_DMA_MODE_ST_DCU | OWL_DMA_MODE_DT_DEV
 402                        | OWL_DMA_MODE_SAM_INC | OWL_DMA_MODE_DAM_CONST;
 403
 404                /*
 405                 * Hardware only supports 32bit and 8bit buswidth. Since the
 406                 * default is 32bit, select 8bit only when requested.
 407                 */
 408                if (sconfig->dst_addr_width == DMA_SLAVE_BUSWIDTH_1_BYTE)
 409                        mode |= OWL_DMA_MODE_NDDBW_8BIT;
 410
 411                break;
 412        case DMA_DEV_TO_MEM:
 413                 mode |= OWL_DMA_MODE_TS(vchan->drq)
 414                        | OWL_DMA_MODE_ST_DEV | OWL_DMA_MODE_DT_DCU
 415                        | OWL_DMA_MODE_SAM_CONST | OWL_DMA_MODE_DAM_INC;
 416
 417                /*
 418                 * Hardware only supports 32bit and 8bit buswidth. Since the
 419                 * default is 32bit, select 8bit only when requested.
 420                 */
 421                if (sconfig->src_addr_width == DMA_SLAVE_BUSWIDTH_1_BYTE)
 422                        mode |= OWL_DMA_MODE_NDDBW_8BIT;
 423
 424                break;
 425        default:
 426                return -EINVAL;
 427        }
 428
 429        lli->hw[OWL_DMADESC_CTRLA] = llc_hw_ctrla(mode,
 430                                                  OWL_DMA_LLC_SAV_LOAD_NEXT |
 431                                                  OWL_DMA_LLC_DAV_LOAD_NEXT);
 432
 433        if (is_cyclic)
 434                ctrlb = llc_hw_ctrlb(OWL_DMA_INTCTL_BLOCK);
 435        else
 436                ctrlb = llc_hw_ctrlb(OWL_DMA_INTCTL_SUPER_BLOCK);
 437
 438        lli->hw[OWL_DMADESC_NEXT_LLI] = 0; /* One link list by default */
 439        lli->hw[OWL_DMADESC_SADDR] = src;
 440        lli->hw[OWL_DMADESC_DADDR] = dst;
 441        lli->hw[OWL_DMADESC_SRC_STRIDE] = 0;
 442        lli->hw[OWL_DMADESC_DST_STRIDE] = 0;
 443
 444        if (od->devid == S700_DMA) {
 445                /* Max frame length is 1MB */
 446                lli->hw[OWL_DMADESC_FLEN] = len;
 447                /*
 448                 * On S700, word starts from offset 0x1C is shared between
 449                 * frame count and ctrlb, where first 12 bits are for frame
 450                 * count and rest of 20 bits are for ctrlb.
 451                 */
 452                lli->hw[OWL_DMADESC_CTRLB] = FCNT_VAL | ctrlb;
 453        } else {
 454                /*
 455                 * On S900, word starts from offset 0xC is shared between
 456                 * frame length (max frame length is 1MB) and frame count,
 457                 * where first 20 bits are for frame length and rest of
 458                 * 12 bits are for frame count.
 459                 */
 460                lli->hw[OWL_DMADESC_FLEN] = len | FCNT_VAL << 20;
 461                lli->hw[OWL_DMADESC_CTRLB] = ctrlb;
 462        }
 463
 464        return 0;
 465}
 466
 467static struct owl_dma_pchan *owl_dma_get_pchan(struct owl_dma *od,
 468                                               struct owl_dma_vchan *vchan)
 469{
 470        struct owl_dma_pchan *pchan = NULL;
 471        unsigned long flags;
 472        int i;
 473
 474        for (i = 0; i < od->nr_pchans; i++) {
 475                pchan = &od->pchans[i];
 476
 477                spin_lock_irqsave(&od->lock, flags);
 478                if (!pchan->vchan) {
 479                        pchan->vchan = vchan;
 480                        spin_unlock_irqrestore(&od->lock, flags);
 481                        break;
 482                }
 483
 484                spin_unlock_irqrestore(&od->lock, flags);
 485        }
 486
 487        return pchan;
 488}
 489
 490static int owl_dma_pchan_busy(struct owl_dma *od, struct owl_dma_pchan *pchan)
 491{
 492        unsigned int val;
 493
 494        val = dma_readl(od, OWL_DMA_IDLE_STAT);
 495
 496        return !(val & (1 << pchan->id));
 497}
 498
 499static void owl_dma_terminate_pchan(struct owl_dma *od,
 500                                    struct owl_dma_pchan *pchan)
 501{
 502        unsigned long flags;
 503        u32 irq_pd;
 504
 505        pchan_writel(pchan, OWL_DMAX_START, 0);
 506        pchan_update(pchan, OWL_DMAX_INT_STATUS, 0xff, false);
 507
 508        spin_lock_irqsave(&od->lock, flags);
 509        dma_update(od, OWL_DMA_IRQ_EN0, (1 << pchan->id), false);
 510
 511        irq_pd = dma_readl(od, OWL_DMA_IRQ_PD0);
 512        if (irq_pd & (1 << pchan->id)) {
 513                dev_warn(od->dma.dev,
 514                         "terminating pchan %d that still has pending irq\n",
 515                         pchan->id);
 516                dma_writel(od, OWL_DMA_IRQ_PD0, (1 << pchan->id));
 517        }
 518
 519        pchan->vchan = NULL;
 520
 521        spin_unlock_irqrestore(&od->lock, flags);
 522}
 523
 524static void owl_dma_pause_pchan(struct owl_dma_pchan *pchan)
 525{
 526        pchan_writel(pchan, 1, OWL_DMAX_PAUSE);
 527}
 528
 529static void owl_dma_resume_pchan(struct owl_dma_pchan *pchan)
 530{
 531        pchan_writel(pchan, 0, OWL_DMAX_PAUSE);
 532}
 533
 534static int owl_dma_start_next_txd(struct owl_dma_vchan *vchan)
 535{
 536        struct owl_dma *od = to_owl_dma(vchan->vc.chan.device);
 537        struct virt_dma_desc *vd = vchan_next_desc(&vchan->vc);
 538        struct owl_dma_pchan *pchan = vchan->pchan;
 539        struct owl_dma_txd *txd = to_owl_txd(&vd->tx);
 540        struct owl_dma_lli *lli;
 541        unsigned long flags;
 542        u32 int_ctl;
 543
 544        list_del(&vd->node);
 545
 546        vchan->txd = txd;
 547
 548        /* Wait for channel inactive */
 549        while (owl_dma_pchan_busy(od, pchan))
 550                cpu_relax();
 551
 552        lli = list_first_entry(&txd->lli_list,
 553                               struct owl_dma_lli, node);
 554
 555        if (txd->cyclic)
 556                int_ctl = OWL_DMA_INTCTL_BLOCK;
 557        else
 558                int_ctl = OWL_DMA_INTCTL_SUPER_BLOCK;
 559
 560        pchan_writel(pchan, OWL_DMAX_MODE, OWL_DMA_MODE_LME);
 561        pchan_writel(pchan, OWL_DMAX_LINKLIST_CTL,
 562                     OWL_DMA_LLC_SAV_LOAD_NEXT | OWL_DMA_LLC_DAV_LOAD_NEXT);
 563        pchan_writel(pchan, OWL_DMAX_NEXT_DESCRIPTOR, lli->phys);
 564        pchan_writel(pchan, OWL_DMAX_INT_CTL, int_ctl);
 565
 566        /* Clear IRQ status for this pchan */
 567        pchan_update(pchan, OWL_DMAX_INT_STATUS, 0xff, false);
 568
 569        spin_lock_irqsave(&od->lock, flags);
 570
 571        dma_update(od, OWL_DMA_IRQ_EN0, (1 << pchan->id), true);
 572
 573        spin_unlock_irqrestore(&od->lock, flags);
 574
 575        dev_dbg(chan2dev(&vchan->vc.chan), "starting pchan %d\n", pchan->id);
 576
 577        /* Start DMA transfer for this pchan */
 578        pchan_writel(pchan, OWL_DMAX_START, 0x1);
 579
 580        return 0;
 581}
 582
 583static void owl_dma_phy_free(struct owl_dma *od, struct owl_dma_vchan *vchan)
 584{
 585        /* Ensure that the physical channel is stopped */
 586        owl_dma_terminate_pchan(od, vchan->pchan);
 587
 588        vchan->pchan = NULL;
 589}
 590
 591static irqreturn_t owl_dma_interrupt(int irq, void *dev_id)
 592{
 593        struct owl_dma *od = dev_id;
 594        struct owl_dma_vchan *vchan;
 595        struct owl_dma_pchan *pchan;
 596        unsigned long pending;
 597        int i;
 598        unsigned int global_irq_pending, chan_irq_pending;
 599
 600        spin_lock(&od->lock);
 601
 602        pending = dma_readl(od, OWL_DMA_IRQ_PD0);
 603
 604        /* Clear IRQ status for each pchan */
 605        for_each_set_bit(i, &pending, od->nr_pchans) {
 606                pchan = &od->pchans[i];
 607                pchan_update(pchan, OWL_DMAX_INT_STATUS, 0xff, false);
 608        }
 609
 610        /* Clear pending IRQ */
 611        dma_writel(od, OWL_DMA_IRQ_PD0, pending);
 612
 613        /* Check missed pending IRQ */
 614        for (i = 0; i < od->nr_pchans; i++) {
 615                pchan = &od->pchans[i];
 616                chan_irq_pending = pchan_readl(pchan, OWL_DMAX_INT_CTL) &
 617                                   pchan_readl(pchan, OWL_DMAX_INT_STATUS);
 618
 619                /* Dummy read to ensure OWL_DMA_IRQ_PD0 value is updated */
 620                dma_readl(od, OWL_DMA_IRQ_PD0);
 621
 622                global_irq_pending = dma_readl(od, OWL_DMA_IRQ_PD0);
 623
 624                if (chan_irq_pending && !(global_irq_pending & BIT(i))) {
 625                        dev_dbg(od->dma.dev,
 626                                "global and channel IRQ pending match err\n");
 627
 628                        /* Clear IRQ status for this pchan */
 629                        pchan_update(pchan, OWL_DMAX_INT_STATUS,
 630                                     0xff, false);
 631
 632                        /* Update global IRQ pending */
 633                        pending |= BIT(i);
 634                }
 635        }
 636
 637        spin_unlock(&od->lock);
 638
 639        for_each_set_bit(i, &pending, od->nr_pchans) {
 640                struct owl_dma_txd *txd;
 641
 642                pchan = &od->pchans[i];
 643
 644                vchan = pchan->vchan;
 645                if (!vchan) {
 646                        dev_warn(od->dma.dev, "no vchan attached on pchan %d\n",
 647                                 pchan->id);
 648                        continue;
 649                }
 650
 651                spin_lock(&vchan->vc.lock);
 652
 653                txd = vchan->txd;
 654                if (txd) {
 655                        vchan->txd = NULL;
 656
 657                        vchan_cookie_complete(&txd->vd);
 658
 659                        /*
 660                         * Start the next descriptor (if any),
 661                         * otherwise free this channel.
 662                         */
 663                        if (vchan_next_desc(&vchan->vc))
 664                                owl_dma_start_next_txd(vchan);
 665                        else
 666                                owl_dma_phy_free(od, vchan);
 667                }
 668
 669                spin_unlock(&vchan->vc.lock);
 670        }
 671
 672        return IRQ_HANDLED;
 673}
 674
 675static void owl_dma_free_txd(struct owl_dma *od, struct owl_dma_txd *txd)
 676{
 677        struct owl_dma_lli *lli, *_lli;
 678
 679        if (unlikely(!txd))
 680                return;
 681
 682        list_for_each_entry_safe(lli, _lli, &txd->lli_list, node)
 683                owl_dma_free_lli(od, lli);
 684
 685        kfree(txd);
 686}
 687
 688static void owl_dma_desc_free(struct virt_dma_desc *vd)
 689{
 690        struct owl_dma *od = to_owl_dma(vd->tx.chan->device);
 691        struct owl_dma_txd *txd = to_owl_txd(&vd->tx);
 692
 693        owl_dma_free_txd(od, txd);
 694}
 695
 696static int owl_dma_terminate_all(struct dma_chan *chan)
 697{
 698        struct owl_dma *od = to_owl_dma(chan->device);
 699        struct owl_dma_vchan *vchan = to_owl_vchan(chan);
 700        unsigned long flags;
 701        LIST_HEAD(head);
 702
 703        spin_lock_irqsave(&vchan->vc.lock, flags);
 704
 705        if (vchan->pchan)
 706                owl_dma_phy_free(od, vchan);
 707
 708        if (vchan->txd) {
 709                owl_dma_desc_free(&vchan->txd->vd);
 710                vchan->txd = NULL;
 711        }
 712
 713        vchan_get_all_descriptors(&vchan->vc, &head);
 714
 715        spin_unlock_irqrestore(&vchan->vc.lock, flags);
 716
 717        vchan_dma_desc_free_list(&vchan->vc, &head);
 718
 719        return 0;
 720}
 721
 722static int owl_dma_config(struct dma_chan *chan,
 723                          struct dma_slave_config *config)
 724{
 725        struct owl_dma_vchan *vchan = to_owl_vchan(chan);
 726
 727        /* Reject definitely invalid configurations */
 728        if (config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
 729            config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
 730                return -EINVAL;
 731
 732        memcpy(&vchan->cfg, config, sizeof(struct dma_slave_config));
 733
 734        return 0;
 735}
 736
 737static int owl_dma_pause(struct dma_chan *chan)
 738{
 739        struct owl_dma_vchan *vchan = to_owl_vchan(chan);
 740        unsigned long flags;
 741
 742        spin_lock_irqsave(&vchan->vc.lock, flags);
 743
 744        owl_dma_pause_pchan(vchan->pchan);
 745
 746        spin_unlock_irqrestore(&vchan->vc.lock, flags);
 747
 748        return 0;
 749}
 750
 751static int owl_dma_resume(struct dma_chan *chan)
 752{
 753        struct owl_dma_vchan *vchan = to_owl_vchan(chan);
 754        unsigned long flags;
 755
 756        if (!vchan->pchan && !vchan->txd)
 757                return 0;
 758
 759        dev_dbg(chan2dev(chan), "vchan %p: resume\n", &vchan->vc);
 760
 761        spin_lock_irqsave(&vchan->vc.lock, flags);
 762
 763        owl_dma_resume_pchan(vchan->pchan);
 764
 765        spin_unlock_irqrestore(&vchan->vc.lock, flags);
 766
 767        return 0;
 768}
 769
 770static u32 owl_dma_getbytes_chan(struct owl_dma_vchan *vchan)
 771{
 772        struct owl_dma_pchan *pchan;
 773        struct owl_dma_txd *txd;
 774        struct owl_dma_lli *lli;
 775        unsigned int next_lli_phy;
 776        size_t bytes;
 777
 778        pchan = vchan->pchan;
 779        txd = vchan->txd;
 780
 781        if (!pchan || !txd)
 782                return 0;
 783
 784        /* Get remain count of current node in link list */
 785        bytes = pchan_readl(pchan, OWL_DMAX_REMAIN_CNT);
 786
 787        /* Loop through the preceding nodes to get total remaining bytes */
 788        if (pchan_readl(pchan, OWL_DMAX_MODE) & OWL_DMA_MODE_LME) {
 789                next_lli_phy = pchan_readl(pchan, OWL_DMAX_NEXT_DESCRIPTOR);
 790                list_for_each_entry(lli, &txd->lli_list, node) {
 791                        /* Start from the next active node */
 792                        if (lli->phys == next_lli_phy) {
 793                                list_for_each_entry(lli, &txd->lli_list, node)
 794                                        bytes += llc_hw_flen(lli);
 795                                break;
 796                        }
 797                }
 798        }
 799
 800        return bytes;
 801}
 802
 803static enum dma_status owl_dma_tx_status(struct dma_chan *chan,
 804                                         dma_cookie_t cookie,
 805                                         struct dma_tx_state *state)
 806{
 807        struct owl_dma_vchan *vchan = to_owl_vchan(chan);
 808        struct owl_dma_lli *lli;
 809        struct virt_dma_desc *vd;
 810        struct owl_dma_txd *txd;
 811        enum dma_status ret;
 812        unsigned long flags;
 813        size_t bytes = 0;
 814
 815        ret = dma_cookie_status(chan, cookie, state);
 816        if (ret == DMA_COMPLETE || !state)
 817                return ret;
 818
 819        spin_lock_irqsave(&vchan->vc.lock, flags);
 820
 821        vd = vchan_find_desc(&vchan->vc, cookie);
 822        if (vd) {
 823                txd = to_owl_txd(&vd->tx);
 824                list_for_each_entry(lli, &txd->lli_list, node)
 825                        bytes += llc_hw_flen(lli);
 826        } else {
 827                bytes = owl_dma_getbytes_chan(vchan);
 828        }
 829
 830        spin_unlock_irqrestore(&vchan->vc.lock, flags);
 831
 832        dma_set_residue(state, bytes);
 833
 834        return ret;
 835}
 836
 837static void owl_dma_phy_alloc_and_start(struct owl_dma_vchan *vchan)
 838{
 839        struct owl_dma *od = to_owl_dma(vchan->vc.chan.device);
 840        struct owl_dma_pchan *pchan;
 841
 842        pchan = owl_dma_get_pchan(od, vchan);
 843        if (!pchan)
 844                return;
 845
 846        dev_dbg(od->dma.dev, "allocated pchan %d\n", pchan->id);
 847
 848        vchan->pchan = pchan;
 849        owl_dma_start_next_txd(vchan);
 850}
 851
 852static void owl_dma_issue_pending(struct dma_chan *chan)
 853{
 854        struct owl_dma_vchan *vchan = to_owl_vchan(chan);
 855        unsigned long flags;
 856
 857        spin_lock_irqsave(&vchan->vc.lock, flags);
 858        if (vchan_issue_pending(&vchan->vc)) {
 859                if (!vchan->pchan)
 860                        owl_dma_phy_alloc_and_start(vchan);
 861        }
 862        spin_unlock_irqrestore(&vchan->vc.lock, flags);
 863}
 864
 865static struct dma_async_tx_descriptor
 866                *owl_dma_prep_memcpy(struct dma_chan *chan,
 867                                     dma_addr_t dst, dma_addr_t src,
 868                                     size_t len, unsigned long flags)
 869{
 870        struct owl_dma *od = to_owl_dma(chan->device);
 871        struct owl_dma_vchan *vchan = to_owl_vchan(chan);
 872        struct owl_dma_txd *txd;
 873        struct owl_dma_lli *lli, *prev = NULL;
 874        size_t offset, bytes;
 875        int ret;
 876
 877        if (!len)
 878                return NULL;
 879
 880        txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
 881        if (!txd)
 882                return NULL;
 883
 884        INIT_LIST_HEAD(&txd->lli_list);
 885
 886        /* Process the transfer as frame by frame */
 887        for (offset = 0; offset < len; offset += bytes) {
 888                lli = owl_dma_alloc_lli(od);
 889                if (!lli) {
 890                        dev_warn(chan2dev(chan), "failed to allocate lli\n");
 891                        goto err_txd_free;
 892                }
 893
 894                bytes = min_t(size_t, (len - offset), OWL_DMA_FRAME_MAX_LENGTH);
 895
 896                ret = owl_dma_cfg_lli(vchan, lli, src + offset, dst + offset,
 897                                      bytes, DMA_MEM_TO_MEM,
 898                                      &vchan->cfg, txd->cyclic);
 899                if (ret) {
 900                        dev_warn(chan2dev(chan), "failed to config lli\n");
 901                        goto err_txd_free;
 902                }
 903
 904                prev = owl_dma_add_lli(txd, prev, lli, false);
 905        }
 906
 907        return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
 908
 909err_txd_free:
 910        owl_dma_free_txd(od, txd);
 911        return NULL;
 912}
 913
 914static struct dma_async_tx_descriptor
 915                *owl_dma_prep_slave_sg(struct dma_chan *chan,
 916                                       struct scatterlist *sgl,
 917                                       unsigned int sg_len,
 918                                       enum dma_transfer_direction dir,
 919                                       unsigned long flags, void *context)
 920{
 921        struct owl_dma *od = to_owl_dma(chan->device);
 922        struct owl_dma_vchan *vchan = to_owl_vchan(chan);
 923        struct dma_slave_config *sconfig = &vchan->cfg;
 924        struct owl_dma_txd *txd;
 925        struct owl_dma_lli *lli, *prev = NULL;
 926        struct scatterlist *sg;
 927        dma_addr_t addr, src = 0, dst = 0;
 928        size_t len;
 929        int ret, i;
 930
 931        txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
 932        if (!txd)
 933                return NULL;
 934
 935        INIT_LIST_HEAD(&txd->lli_list);
 936
 937        for_each_sg(sgl, sg, sg_len, i) {
 938                addr = sg_dma_address(sg);
 939                len = sg_dma_len(sg);
 940
 941                if (len > OWL_DMA_FRAME_MAX_LENGTH) {
 942                        dev_err(od->dma.dev,
 943                                "frame length exceeds max supported length");
 944                        goto err_txd_free;
 945                }
 946
 947                lli = owl_dma_alloc_lli(od);
 948                if (!lli) {
 949                        dev_err(chan2dev(chan), "failed to allocate lli");
 950                        goto err_txd_free;
 951                }
 952
 953                if (dir == DMA_MEM_TO_DEV) {
 954                        src = addr;
 955                        dst = sconfig->dst_addr;
 956                } else {
 957                        src = sconfig->src_addr;
 958                        dst = addr;
 959                }
 960
 961                ret = owl_dma_cfg_lli(vchan, lli, src, dst, len, dir, sconfig,
 962                                      txd->cyclic);
 963                if (ret) {
 964                        dev_warn(chan2dev(chan), "failed to config lli");
 965                        goto err_txd_free;
 966                }
 967
 968                prev = owl_dma_add_lli(txd, prev, lli, false);
 969        }
 970
 971        return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
 972
 973err_txd_free:
 974        owl_dma_free_txd(od, txd);
 975
 976        return NULL;
 977}
 978
 979static struct dma_async_tx_descriptor
 980                *owl_prep_dma_cyclic(struct dma_chan *chan,
 981                                     dma_addr_t buf_addr, size_t buf_len,
 982                                     size_t period_len,
 983                                     enum dma_transfer_direction dir,
 984                                     unsigned long flags)
 985{
 986        struct owl_dma *od = to_owl_dma(chan->device);
 987        struct owl_dma_vchan *vchan = to_owl_vchan(chan);
 988        struct dma_slave_config *sconfig = &vchan->cfg;
 989        struct owl_dma_txd *txd;
 990        struct owl_dma_lli *lli, *prev = NULL, *first = NULL;
 991        dma_addr_t src = 0, dst = 0;
 992        unsigned int periods = buf_len / period_len;
 993        int ret, i;
 994
 995        txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
 996        if (!txd)
 997                return NULL;
 998
 999        INIT_LIST_HEAD(&txd->lli_list);
1000        txd->cyclic = true;
1001
1002        for (i = 0; i < periods; i++) {
1003                lli = owl_dma_alloc_lli(od);
1004                if (!lli) {
1005                        dev_warn(chan2dev(chan), "failed to allocate lli");
1006                        goto err_txd_free;
1007                }
1008
1009                if (dir == DMA_MEM_TO_DEV) {
1010                        src = buf_addr + (period_len * i);
1011                        dst = sconfig->dst_addr;
1012                } else if (dir == DMA_DEV_TO_MEM) {
1013                        src = sconfig->src_addr;
1014                        dst = buf_addr + (period_len * i);
1015                }
1016
1017                ret = owl_dma_cfg_lli(vchan, lli, src, dst, period_len,
1018                                      dir, sconfig, txd->cyclic);
1019                if (ret) {
1020                        dev_warn(chan2dev(chan), "failed to config lli");
1021                        goto err_txd_free;
1022                }
1023
1024                if (!first)
1025                        first = lli;
1026
1027                prev = owl_dma_add_lli(txd, prev, lli, false);
1028        }
1029
1030        /* close the cyclic list */
1031        owl_dma_add_lli(txd, prev, first, true);
1032
1033        return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
1034
1035err_txd_free:
1036        owl_dma_free_txd(od, txd);
1037
1038        return NULL;
1039}
1040
1041static void owl_dma_free_chan_resources(struct dma_chan *chan)
1042{
1043        struct owl_dma_vchan *vchan = to_owl_vchan(chan);
1044
1045        /* Ensure all queued descriptors are freed */
1046        vchan_free_chan_resources(&vchan->vc);
1047}
1048
1049static inline void owl_dma_free(struct owl_dma *od)
1050{
1051        struct owl_dma_vchan *vchan = NULL;
1052        struct owl_dma_vchan *next;
1053
1054        list_for_each_entry_safe(vchan,
1055                                 next, &od->dma.channels, vc.chan.device_node) {
1056                list_del(&vchan->vc.chan.device_node);
1057                tasklet_kill(&vchan->vc.task);
1058        }
1059}
1060
1061static struct dma_chan *owl_dma_of_xlate(struct of_phandle_args *dma_spec,
1062                                         struct of_dma *ofdma)
1063{
1064        struct owl_dma *od = ofdma->of_dma_data;
1065        struct owl_dma_vchan *vchan;
1066        struct dma_chan *chan;
1067        u8 drq = dma_spec->args[0];
1068
1069        if (drq > od->nr_vchans)
1070                return NULL;
1071
1072        chan = dma_get_any_slave_channel(&od->dma);
1073        if (!chan)
1074                return NULL;
1075
1076        vchan = to_owl_vchan(chan);
1077        vchan->drq = drq;
1078
1079        return chan;
1080}
1081
1082static const struct of_device_id owl_dma_match[] = {
1083        { .compatible = "actions,s500-dma", .data = (void *)S900_DMA,},
1084        { .compatible = "actions,s700-dma", .data = (void *)S700_DMA,},
1085        { .compatible = "actions,s900-dma", .data = (void *)S900_DMA,},
1086        { /* sentinel */ },
1087};
1088MODULE_DEVICE_TABLE(of, owl_dma_match);
1089
1090static int owl_dma_probe(struct platform_device *pdev)
1091{
1092        struct device_node *np = pdev->dev.of_node;
1093        struct owl_dma *od;
1094        int ret, i, nr_channels, nr_requests;
1095
1096        od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL);
1097        if (!od)
1098                return -ENOMEM;
1099
1100        od->base = devm_platform_ioremap_resource(pdev, 0);
1101        if (IS_ERR(od->base))
1102                return PTR_ERR(od->base);
1103
1104        ret = of_property_read_u32(np, "dma-channels", &nr_channels);
1105        if (ret) {
1106                dev_err(&pdev->dev, "can't get dma-channels\n");
1107                return ret;
1108        }
1109
1110        ret = of_property_read_u32(np, "dma-requests", &nr_requests);
1111        if (ret) {
1112                dev_err(&pdev->dev, "can't get dma-requests\n");
1113                return ret;
1114        }
1115
1116        dev_info(&pdev->dev, "dma-channels %d, dma-requests %d\n",
1117                 nr_channels, nr_requests);
1118
1119        od->devid = (enum owl_dma_id)of_device_get_match_data(&pdev->dev);
1120
1121        od->nr_pchans = nr_channels;
1122        od->nr_vchans = nr_requests;
1123
1124        pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
1125
1126        platform_set_drvdata(pdev, od);
1127        spin_lock_init(&od->lock);
1128
1129        dma_cap_set(DMA_MEMCPY, od->dma.cap_mask);
1130        dma_cap_set(DMA_SLAVE, od->dma.cap_mask);
1131        dma_cap_set(DMA_CYCLIC, od->dma.cap_mask);
1132
1133        od->dma.dev = &pdev->dev;
1134        od->dma.device_free_chan_resources = owl_dma_free_chan_resources;
1135        od->dma.device_tx_status = owl_dma_tx_status;
1136        od->dma.device_issue_pending = owl_dma_issue_pending;
1137        od->dma.device_prep_dma_memcpy = owl_dma_prep_memcpy;
1138        od->dma.device_prep_slave_sg = owl_dma_prep_slave_sg;
1139        od->dma.device_prep_dma_cyclic = owl_prep_dma_cyclic;
1140        od->dma.device_config = owl_dma_config;
1141        od->dma.device_pause = owl_dma_pause;
1142        od->dma.device_resume = owl_dma_resume;
1143        od->dma.device_terminate_all = owl_dma_terminate_all;
1144        od->dma.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1145        od->dma.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1146        od->dma.directions = BIT(DMA_MEM_TO_MEM);
1147        od->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1148
1149        INIT_LIST_HEAD(&od->dma.channels);
1150
1151        od->clk = devm_clk_get(&pdev->dev, NULL);
1152        if (IS_ERR(od->clk)) {
1153                dev_err(&pdev->dev, "unable to get clock\n");
1154                return PTR_ERR(od->clk);
1155        }
1156
1157        /*
1158         * Eventhough the DMA controller is capable of generating 4
1159         * IRQ's for DMA priority feature, we only use 1 IRQ for
1160         * simplification.
1161         */
1162        od->irq = platform_get_irq(pdev, 0);
1163        ret = devm_request_irq(&pdev->dev, od->irq, owl_dma_interrupt, 0,
1164                               dev_name(&pdev->dev), od);
1165        if (ret) {
1166                dev_err(&pdev->dev, "unable to request IRQ\n");
1167                return ret;
1168        }
1169
1170        /* Init physical channel */
1171        od->pchans = devm_kcalloc(&pdev->dev, od->nr_pchans,
1172                                  sizeof(struct owl_dma_pchan), GFP_KERNEL);
1173        if (!od->pchans)
1174                return -ENOMEM;
1175
1176        for (i = 0; i < od->nr_pchans; i++) {
1177                struct owl_dma_pchan *pchan = &od->pchans[i];
1178
1179                pchan->id = i;
1180                pchan->base = od->base + OWL_DMA_CHAN_BASE(i);
1181        }
1182
1183        /* Init virtual channel */
1184        od->vchans = devm_kcalloc(&pdev->dev, od->nr_vchans,
1185                                  sizeof(struct owl_dma_vchan), GFP_KERNEL);
1186        if (!od->vchans)
1187                return -ENOMEM;
1188
1189        for (i = 0; i < od->nr_vchans; i++) {
1190                struct owl_dma_vchan *vchan = &od->vchans[i];
1191
1192                vchan->vc.desc_free = owl_dma_desc_free;
1193                vchan_init(&vchan->vc, &od->dma);
1194        }
1195
1196        /* Create a pool of consistent memory blocks for hardware descriptors */
1197        od->lli_pool = dma_pool_create(dev_name(od->dma.dev), od->dma.dev,
1198                                       sizeof(struct owl_dma_lli),
1199                                       __alignof__(struct owl_dma_lli),
1200                                       0);
1201        if (!od->lli_pool) {
1202                dev_err(&pdev->dev, "unable to allocate DMA descriptor pool\n");
1203                return -ENOMEM;
1204        }
1205
1206        clk_prepare_enable(od->clk);
1207
1208        ret = dma_async_device_register(&od->dma);
1209        if (ret) {
1210                dev_err(&pdev->dev, "failed to register DMA engine device\n");
1211                goto err_pool_free;
1212        }
1213
1214        /* Device-tree DMA controller registration */
1215        ret = of_dma_controller_register(pdev->dev.of_node,
1216                                         owl_dma_of_xlate, od);
1217        if (ret) {
1218                dev_err(&pdev->dev, "of_dma_controller_register failed\n");
1219                goto err_dma_unregister;
1220        }
1221
1222        return 0;
1223
1224err_dma_unregister:
1225        dma_async_device_unregister(&od->dma);
1226err_pool_free:
1227        clk_disable_unprepare(od->clk);
1228        dma_pool_destroy(od->lli_pool);
1229
1230        return ret;
1231}
1232
1233static int owl_dma_remove(struct platform_device *pdev)
1234{
1235        struct owl_dma *od = platform_get_drvdata(pdev);
1236
1237        of_dma_controller_free(pdev->dev.of_node);
1238        dma_async_device_unregister(&od->dma);
1239
1240        /* Mask all interrupts for this execution environment */
1241        dma_writel(od, OWL_DMA_IRQ_EN0, 0x0);
1242
1243        /* Make sure we won't have any further interrupts */
1244        devm_free_irq(od->dma.dev, od->irq, od);
1245
1246        owl_dma_free(od);
1247
1248        clk_disable_unprepare(od->clk);
1249        dma_pool_destroy(od->lli_pool);
1250
1251        return 0;
1252}
1253
1254static struct platform_driver owl_dma_driver = {
1255        .probe  = owl_dma_probe,
1256        .remove = owl_dma_remove,
1257        .driver = {
1258                .name = "dma-owl",
1259                .of_match_table = of_match_ptr(owl_dma_match),
1260        },
1261};
1262
1263static int owl_dma_init(void)
1264{
1265        return platform_driver_register(&owl_dma_driver);
1266}
1267subsys_initcall(owl_dma_init);
1268
1269static void __exit owl_dma_exit(void)
1270{
1271        platform_driver_unregister(&owl_dma_driver);
1272}
1273module_exit(owl_dma_exit);
1274
1275MODULE_AUTHOR("David Liu <liuwei@actions-semi.com>");
1276MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
1277MODULE_DESCRIPTION("Actions Semi Owl SoCs DMA driver");
1278MODULE_LICENSE("GPL");
1279