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