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