drivers/dma/tegra20-apb-dma.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * DMA driver for Nvidia's Tegra20 APB DMA controller.
   4  *
   5  * Copyright (c) 2012-2013, NVIDIA CORPORATION.  All rights reserved.
   6  */
   7
   8 #include <linux/bitops.h>
   9 #include <linux/clk.h>
  10 #include <linux/delay.h>
  11 #include <linux/dmaengine.h>
  12 #include <linux/dma-mapping.h>
  13 #include <linux/err.h>
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/io.h>
  17 #include <linux/mm.h>
  18 #include <linux/module.h>
  19 #include <linux/of.h>
  20 #include <linux/of_device.h>
  21 #include <linux/of_dma.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/pm.h>
  24 #include <linux/pm_runtime.h>
  25 #include <linux/reset.h>
  26 #include <linux/slab.h>
  27
  28 #include "dmaengine.h"
  29
  30 #define CREATE_TRACE_POINTS
  31 #include <trace/events/tegra_apb_dma.h>
  32
  33 #define TEGRA_APBDMA_GENERAL                    0x0
  34 #define TEGRA_APBDMA_GENERAL_ENABLE             BIT(31)
  35
  36 #define TEGRA_APBDMA_CONTROL                    0x010
  37 #define TEGRA_APBDMA_IRQ_MASK                   0x01c
  38 #define TEGRA_APBDMA_IRQ_MASK_SET               0x020
  39
  40 /* CSR register */
  41 #define TEGRA_APBDMA_CHAN_CSR                   0x00
  42 #define TEGRA_APBDMA_CSR_ENB                    BIT(31)
  43 #define TEGRA_APBDMA_CSR_IE_EOC                 BIT(30)
  44 #define TEGRA_APBDMA_CSR_HOLD                   BIT(29)
  45 #define TEGRA_APBDMA_CSR_DIR                    BIT(28)
  46 #define TEGRA_APBDMA_CSR_ONCE                   BIT(27)
  47 #define TEGRA_APBDMA_CSR_FLOW                   BIT(21)
  48 #define TEGRA_APBDMA_CSR_REQ_SEL_SHIFT          16
  49 #define TEGRA_APBDMA_CSR_REQ_SEL_MASK           0x1F
  50 #define TEGRA_APBDMA_CSR_WCOUNT_MASK            0xFFFC
  51
  52 /* STATUS register */
  53 #define TEGRA_APBDMA_CHAN_STATUS                0x004
  54 #define TEGRA_APBDMA_STATUS_BUSY                BIT(31)
  55 #define TEGRA_APBDMA_STATUS_ISE_EOC             BIT(30)
  56 #define TEGRA_APBDMA_STATUS_HALT                BIT(29)
  57 #define TEGRA_APBDMA_STATUS_PING_PONG           BIT(28)
  58 #define TEGRA_APBDMA_STATUS_COUNT_SHIFT         2
  59 #define TEGRA_APBDMA_STATUS_COUNT_MASK          0xFFFC
  60
  61 #define TEGRA_APBDMA_CHAN_CSRE                  0x00C
  62 #define TEGRA_APBDMA_CHAN_CSRE_PAUSE            (1 << 31)
  63
  64 /* AHB memory address */
  65 #define TEGRA_APBDMA_CHAN_AHBPTR                0x010
  66
  67 /* AHB sequence register */
  68 #define TEGRA_APBDMA_CHAN_AHBSEQ                0x14
  69 #define TEGRA_APBDMA_AHBSEQ_INTR_ENB            BIT(31)
  70 #define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_8         (0 << 28)
  71 #define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_16        (1 << 28)
  72 #define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32        (2 << 28)
  73 #define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_64        (3 << 28)
  74 #define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_128       (4 << 28)
  75 #define TEGRA_APBDMA_AHBSEQ_DATA_SWAP           BIT(27)
  76 #define TEGRA_APBDMA_AHBSEQ_BURST_1             (4 << 24)
  77 #define TEGRA_APBDMA_AHBSEQ_BURST_4             (5 << 24)
  78 #define TEGRA_APBDMA_AHBSEQ_BURST_8             (6 << 24)
  79 #define TEGRA_APBDMA_AHBSEQ_DBL_BUF             BIT(19)
  80 #define TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT          16
  81 #define TEGRA_APBDMA_AHBSEQ_WRAP_NONE           0
  82
  83 /* APB address */
  84 #define TEGRA_APBDMA_CHAN_APBPTR                0x018
  85
  86 /* APB sequence register */
  87 #define TEGRA_APBDMA_CHAN_APBSEQ                0x01c
  88 #define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_8         (0 << 28)
  89 #define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_16        (1 << 28)
  90 #define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32        (2 << 28)
  91 #define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_64        (3 << 28)
  92 #define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_128       (4 << 28)
  93 #define TEGRA_APBDMA_APBSEQ_DATA_SWAP           BIT(27)
  94 #define TEGRA_APBDMA_APBSEQ_WRAP_WORD_1         (1 << 16)
  95
  96 /* Tegra148 specific registers */
  97 #define TEGRA_APBDMA_CHAN_WCOUNT                0x20
  98
  99 #define TEGRA_APBDMA_CHAN_WORD_TRANSFER         0x24
 100
 101 /*
 102  * If any burst is in flight and DMA paused then this is the time to complete
 103  * on-flight burst and update DMA status register.
 104  */
 105 #define TEGRA_APBDMA_BURST_COMPLETE_TIME        20
 106
 107 /* Channel base address offset from APBDMA base address */
 108 #define TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET    0x1000
 109
 110 #define TEGRA_APBDMA_SLAVE_ID_INVALID   (TEGRA_APBDMA_CSR_REQ_SEL_MASK + 1)
 111
 112 struct tegra_dma;
 113
 114 /*
 115  * tegra_dma_chip_data Tegra chip specific DMA data
 116  * @nr_channels: Number of channels available in the controller.
 117  * @channel_reg_size: Channel register size/stride.
 118  * @max_dma_count: Maximum DMA transfer count supported by DMA controller.
 119  * @support_channel_pause: Support channel wise pause of dma.
 120  * @support_separate_wcount_reg: Support separate word count register.
 121  */
 122 struct tegra_dma_chip_data {
 123         int nr_channels;
 124         int channel_reg_size;
 125         int max_dma_count;
 126         bool support_channel_pause;
 127         bool support_separate_wcount_reg;
 128 };
 129
 130 /* DMA channel registers */
 131 struct tegra_dma_channel_regs {
 132         unsigned long   csr;
 133         unsigned long   ahb_ptr;
 134         unsigned long   apb_ptr;
 135         unsigned long   ahb_seq;
 136         unsigned long   apb_seq;
 137         unsigned long   wcount;
 138 };
 139
 140 /*
 141  * tegra_dma_sg_req: DMA request details to configure hardware. This
 142  * contains the details for one transfer to configure DMA hw.
 143  * The client's request for data transfer can be broken into multiple
 144  * sub-transfer as per requester details and hw support.
 145  * This sub transfer get added in the list of transfer and point to Tegra
 146  * DMA descriptor which manages the transfer details.
 147  */
 148 struct tegra_dma_sg_req {
 149         struct tegra_dma_channel_regs   ch_regs;
 150         unsigned int                    req_len;
 151         bool                            configured;
 152         bool                            last_sg;
 153         struct list_head                node;
 154         struct tegra_dma_desc           *dma_desc;
 155         unsigned int                    words_xferred;
 156 };
 157
 158 /*
 159  * tegra_dma_desc: Tegra DMA descriptors which manages the client requests.
 160  * This descriptor keep track of transfer status, callbacks and request
 161  * counts etc.
 162  */
 163 struct tegra_dma_desc {
 164         struct dma_async_tx_descriptor  txd;
 165         unsigned int                    bytes_requested;
 166         unsigned int                    bytes_transferred;
 167         enum dma_status                 dma_status;
 168         struct list_head                node;
 169         struct list_head                tx_list;
 170         struct list_head                cb_node;
 171         int                             cb_count;
 172 };
 173
 174 struct tegra_dma_channel;
 175
 176 typedef void (*dma_isr_handler)(struct tegra_dma_channel *tdc,
 177                                 bool to_terminate);
 178
 179 /* tegra_dma_channel: Channel specific information */
 180 struct tegra_dma_channel {
 181         struct dma_chan         dma_chan;
 182         char                    name[12];
 183         bool                    config_init;
 184         int                     id;
 185         int                     irq;
 186         void __iomem            *chan_addr;
 187         spinlock_t              lock;
 188         bool                    busy;
 189         struct tegra_dma        *tdma;
 190         bool                    cyclic;
 191
 192         /* Different lists for managing the requests */
 193         struct list_head        free_sg_req;
 194         struct list_head        pending_sg_req;
 195         struct list_head        free_dma_desc;
 196         struct list_head        cb_desc;
 197
 198         /* ISR handler and tasklet for bottom half of isr handling */
 199         dma_isr_handler         isr_handler;
 200         struct tasklet_struct   tasklet;
 201
 202         /* Channel-slave specific configuration */
 203         unsigned int slave_id;
 204         struct dma_slave_config dma_sconfig;
 205         struct tegra_dma_channel_regs   channel_reg;
 206 };
 207
 208 /* tegra_dma: Tegra DMA specific information */
 209 struct tegra_dma {
 210         struct dma_device               dma_dev;
 211         struct device                   *dev;
 212         struct clk                      *dma_clk;
 213         struct reset_control            *rst;
 214         spinlock_t                      global_lock;
 215         void __iomem                    *base_addr;
 216         const struct tegra_dma_chip_data *chip_data;
 217
 218         /*
 219          * Counter for managing global pausing of the DMA controller.
 220          * Only applicable for devices that don't support individual
 221          * channel pausing.
 222          */
 223         u32                             global_pause_count;
 224
 225         /* Some register need to be cache before suspend */
 226         u32                             reg_gen;
 227
 228         /* Last member of the structure */
 229         struct tegra_dma_channel channels[0];
 230 };
 231
 232 static inline void tdma_write(struct tegra_dma *tdma, u32 reg, u32 val)
 233 {
 234         writel(val, tdma->base_addr + reg);
 235 }
 236
 237 static inline u32 tdma_read(struct tegra_dma *tdma, u32 reg)
 238 {
 239         return readl(tdma->base_addr + reg);
 240 }
 241
 242 static inline void tdc_write(struct tegra_dma_channel *tdc,
 243                 u32 reg, u32 val)
 244 {
 245         writel(val, tdc->chan_addr + reg);
 246 }
 247
 248 static inline u32 tdc_read(struct tegra_dma_channel *tdc, u32 reg)
 249 {
 250         return readl(tdc->chan_addr + reg);
 251 }
 252
 253 static inline struct tegra_dma_channel *to_tegra_dma_chan(struct dma_chan *dc)
 254 {
 255         return container_of(dc, struct tegra_dma_channel, dma_chan);
 256 }
 257
 258 static inline struct tegra_dma_desc *txd_to_tegra_dma_desc(
 259                 struct dma_async_tx_descriptor *td)
 260 {
 261         return container_of(td, struct tegra_dma_desc, txd);
 262 }
 263
 264 static inline struct device *tdc2dev(struct tegra_dma_channel *tdc)
 265 {
 266         return &tdc->dma_chan.dev->device;
 267 }
 268
 269 static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *tx);
 270 static int tegra_dma_runtime_suspend(struct device *dev);
 271 static int tegra_dma_runtime_resume(struct device *dev);
 272
 273 /* Get DMA desc from free list, if not there then allocate it.  */
 274 static struct tegra_dma_desc *tegra_dma_desc_get(
 275                 struct tegra_dma_channel *tdc)
 276 {
 277         struct tegra_dma_desc *dma_desc;
 278         unsigned long flags;
 279
 280         spin_lock_irqsave(&tdc->lock, flags);
 281
 282         /* Do not allocate if desc are waiting for ack */
 283         list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
 284                 if (async_tx_test_ack(&dma_desc->txd) && !dma_desc->cb_count) {
 285                         list_del(&dma_desc->node);
 286                         spin_unlock_irqrestore(&tdc->lock, flags);
 287                         dma_desc->txd.flags = 0;
 288                         return dma_desc;
 289                 }
 290         }
 291
 292         spin_unlock_irqrestore(&tdc->lock, flags);
 293
 294         /* Allocate DMA desc */
 295         dma_desc = kzalloc(sizeof(*dma_desc), GFP_NOWAIT);
 296         if (!dma_desc)
 297                 return NULL;
 298
 299         dma_async_tx_descriptor_init(&dma_desc->txd, &tdc->dma_chan);
 300         dma_desc->txd.tx_submit = tegra_dma_tx_submit;
 301         dma_desc->txd.flags = 0;
 302         return dma_desc;
 303 }
 304
 305 static void tegra_dma_desc_put(struct tegra_dma_channel *tdc,
 306                 struct tegra_dma_desc *dma_desc)
 307 {
 308         unsigned long flags;
 309
 310         spin_lock_irqsave(&tdc->lock, flags);
 311         if (!list_empty(&dma_desc->tx_list))
 312                 list_splice_init(&dma_desc->tx_list, &tdc->free_sg_req);
 313         list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
 314         spin_unlock_irqrestore(&tdc->lock, flags);
 315 }
 316
 317 static struct tegra_dma_sg_req *tegra_dma_sg_req_get(
 318                 struct tegra_dma_channel *tdc)
 319 {
 320         struct tegra_dma_sg_req *sg_req = NULL;
 321         unsigned long flags;
 322
 323         spin_lock_irqsave(&tdc->lock, flags);
 324         if (!list_empty(&tdc->free_sg_req)) {
 325                 sg_req = list_first_entry(&tdc->free_sg_req,
 326                                         typeof(*sg_req), node);
 327                 list_del(&sg_req->node);
 328                 spin_unlock_irqrestore(&tdc->lock, flags);
 329                 return sg_req;
 330         }
 331         spin_unlock_irqrestore(&tdc->lock, flags);
 332
 333         sg_req = kzalloc(sizeof(struct tegra_dma_sg_req), GFP_NOWAIT);
 334
 335         return sg_req;
 336 }
 337
 338 static int tegra_dma_slave_config(struct dma_chan *dc,
 339                 struct dma_slave_config *sconfig)
 340 {
 341         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 342
 343         if (!list_empty(&tdc->pending_sg_req)) {
 344                 dev_err(tdc2dev(tdc), "Configuration not allowed\n");
 345                 return -EBUSY;
 346         }
 347
 348         memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig));
 349         if (tdc->slave_id == TEGRA_APBDMA_SLAVE_ID_INVALID &&
 350             sconfig->device_fc) {
 351                 if (sconfig->slave_id > TEGRA_APBDMA_CSR_REQ_SEL_MASK)
 352                         return -EINVAL;
 353                 tdc->slave_id = sconfig->slave_id;
 354         }
 355         tdc->config_init = true;
 356         return 0;
 357 }
 358
 359 static void tegra_dma_global_pause(struct tegra_dma_channel *tdc,
 360         bool wait_for_burst_complete)
 361 {
 362         struct tegra_dma *tdma = tdc->tdma;
 363
 364         spin_lock(&tdma->global_lock);
 365
 366         if (tdc->tdma->global_pause_count == 0) {
 367                 tdma_write(tdma, TEGRA_APBDMA_GENERAL, 0);
 368                 if (wait_for_burst_complete)
 369                         udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
 370         }
 371
 372         tdc->tdma->global_pause_count++;
 373
 374         spin_unlock(&tdma->global_lock);
 375 }
 376
 377 static void tegra_dma_global_resume(struct tegra_dma_channel *tdc)
 378 {
 379         struct tegra_dma *tdma = tdc->tdma;
 380
 381         spin_lock(&tdma->global_lock);
 382
 383         if (WARN_ON(tdc->tdma->global_pause_count == 0))
 384                 goto out;
 385
 386         if (--tdc->tdma->global_pause_count == 0)
 387                 tdma_write(tdma, TEGRA_APBDMA_GENERAL,
 388                            TEGRA_APBDMA_GENERAL_ENABLE);
 389
 390 out:
 391         spin_unlock(&tdma->global_lock);
 392 }
 393
 394 static void tegra_dma_pause(struct tegra_dma_channel *tdc,
 395         bool wait_for_burst_complete)
 396 {
 397         struct tegra_dma *tdma = tdc->tdma;
 398
 399         if (tdma->chip_data->support_channel_pause) {
 400                 tdc_write(tdc, TEGRA_APBDMA_CHAN_CSRE,
 401                                 TEGRA_APBDMA_CHAN_CSRE_PAUSE);
 402                 if (wait_for_burst_complete)
 403                         udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
 404         } else {
 405                 tegra_dma_global_pause(tdc, wait_for_burst_complete);
 406         }
 407 }
 408
 409 static void tegra_dma_resume(struct tegra_dma_channel *tdc)
 410 {
 411         struct tegra_dma *tdma = tdc->tdma;
 412
 413         if (tdma->chip_data->support_channel_pause) {
 414                 tdc_write(tdc, TEGRA_APBDMA_CHAN_CSRE, 0);
 415         } else {
 416                 tegra_dma_global_resume(tdc);
 417         }
 418 }
 419
 420 static void tegra_dma_stop(struct tegra_dma_channel *tdc)
 421 {
 422         u32 csr;
 423         u32 status;
 424
 425         /* Disable interrupts */
 426         csr = tdc_read(tdc, TEGRA_APBDMA_CHAN_CSR);
 427         csr &= ~TEGRA_APBDMA_CSR_IE_EOC;
 428         tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, csr);
 429
 430         /* Disable DMA */
 431         csr &= ~TEGRA_APBDMA_CSR_ENB;
 432         tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, csr);
 433
 434         /* Clear interrupt status if it is there */
 435         status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 436         if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 437                 dev_dbg(tdc2dev(tdc), "%s():clearing interrupt\n", __func__);
 438                 tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
 439         }
 440         tdc->busy = false;
 441 }
 442
 443 static void tegra_dma_start(struct tegra_dma_channel *tdc,
 444                 struct tegra_dma_sg_req *sg_req)
 445 {
 446         struct tegra_dma_channel_regs *ch_regs = &sg_req->ch_regs;
 447
 448         tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, ch_regs->csr);
 449         tdc_write(tdc, TEGRA_APBDMA_CHAN_APBSEQ, ch_regs->apb_seq);
 450         tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, ch_regs->apb_ptr);
 451         tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBSEQ, ch_regs->ahb_seq);
 452         tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, ch_regs->ahb_ptr);
 453         if (tdc->tdma->chip_data->support_separate_wcount_reg)
 454                 tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT, ch_regs->wcount);
 455
 456         /* Start DMA */
 457         tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
 458                                 ch_regs->csr | TEGRA_APBDMA_CSR_ENB);
 459 }
 460
 461 static void tegra_dma_configure_for_next(struct tegra_dma_channel *tdc,
 462                 struct tegra_dma_sg_req *nsg_req)
 463 {
 464         unsigned long status;
 465
 466         /*
 467          * The DMA controller reloads the new configuration for next transfer
 468          * after last burst of current transfer completes.
 469          * If there is no IEC status then this makes sure that last burst
 470          * has not be completed. There may be case that last burst is on
 471          * flight and so it can complete but because DMA is paused, it
 472          * will not generates interrupt as well as not reload the new
 473          * configuration.
 474          * If there is already IEC status then interrupt handler need to
 475          * load new configuration.
 476          */
 477         tegra_dma_pause(tdc, false);
 478         status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 479
 480         /*
 481          * If interrupt is pending then do nothing as the ISR will handle
 482          * the programing for new request.
 483          */
 484         if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 485                 dev_err(tdc2dev(tdc),
 486                         "Skipping new configuration as interrupt is pending\n");
 487                 tegra_dma_resume(tdc);
 488                 return;
 489         }
 490
 491         /* Safe to program new configuration */
 492         tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, nsg_req->ch_regs.apb_ptr);
 493         tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, nsg_req->ch_regs.ahb_ptr);
 494         if (tdc->tdma->chip_data->support_separate_wcount_reg)
 495                 tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT,
 496                                                 nsg_req->ch_regs.wcount);
 497         tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
 498                                 nsg_req->ch_regs.csr | TEGRA_APBDMA_CSR_ENB);
 499         nsg_req->configured = true;
 500         nsg_req->words_xferred = 0;
 501
 502         tegra_dma_resume(tdc);
 503 }
 504
 505 static void tdc_start_head_req(struct tegra_dma_channel *tdc)
 506 {
 507         struct tegra_dma_sg_req *sg_req;
 508
 509         if (list_empty(&tdc->pending_sg_req))
 510                 return;
 511
 512         sg_req = list_first_entry(&tdc->pending_sg_req,
 513                                         typeof(*sg_req), node);
 514         tegra_dma_start(tdc, sg_req);
 515         sg_req->configured = true;
 516         sg_req->words_xferred = 0;
 517         tdc->busy = true;
 518 }
 519
 520 static void tdc_configure_next_head_desc(struct tegra_dma_channel *tdc)
 521 {
 522         struct tegra_dma_sg_req *hsgreq;
 523         struct tegra_dma_sg_req *hnsgreq;
 524
 525         if (list_empty(&tdc->pending_sg_req))
 526                 return;
 527
 528         hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
 529         if (!list_is_last(&hsgreq->node, &tdc->pending_sg_req)) {
 530                 hnsgreq = list_first_entry(&hsgreq->node,
 531                                         typeof(*hnsgreq), node);
 532                 tegra_dma_configure_for_next(tdc, hnsgreq);
 533         }
 534 }
 535
 536 static inline int get_current_xferred_count(struct tegra_dma_channel *tdc,
 537         struct tegra_dma_sg_req *sg_req, unsigned long status)
 538 {
 539         return sg_req->req_len - (status & TEGRA_APBDMA_STATUS_COUNT_MASK) - 4;
 540 }
 541
 542 static void tegra_dma_abort_all(struct tegra_dma_channel *tdc)
 543 {
 544         struct tegra_dma_sg_req *sgreq;
 545         struct tegra_dma_desc *dma_desc;
 546
 547         while (!list_empty(&tdc->pending_sg_req)) {
 548                 sgreq = list_first_entry(&tdc->pending_sg_req,
 549                                                 typeof(*sgreq), node);
 550                 list_move_tail(&sgreq->node, &tdc->free_sg_req);
 551                 if (sgreq->last_sg) {
 552                         dma_desc = sgreq->dma_desc;
 553                         dma_desc->dma_status = DMA_ERROR;
 554                         list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
 555
 556                         /* Add in cb list if it is not there. */
 557                         if (!dma_desc->cb_count)
 558                                 list_add_tail(&dma_desc->cb_node,
 559                                                         &tdc->cb_desc);
 560                         dma_desc->cb_count++;
 561                 }
 562         }
 563         tdc->isr_handler = NULL;
 564 }
 565
 566 static bool handle_continuous_head_request(struct tegra_dma_channel *tdc,
 567                 struct tegra_dma_sg_req *last_sg_req, bool to_terminate)
 568 {
 569         struct tegra_dma_sg_req *hsgreq = NULL;
 570
 571         if (list_empty(&tdc->pending_sg_req)) {
 572                 dev_err(tdc2dev(tdc), "DMA is running without req\n");
 573                 tegra_dma_stop(tdc);
 574                 return false;
 575         }
 576
 577         /*
 578          * Check that head req on list should be in flight.
 579          * If it is not in flight then abort transfer as
 580          * looping of transfer can not continue.
 581          */
 582         hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
 583         if (!hsgreq->configured) {
 584                 tegra_dma_stop(tdc);
 585                 dev_err(tdc2dev(tdc), "Error in DMA transfer, aborting DMA\n");
 586                 tegra_dma_abort_all(tdc);
 587                 return false;
 588         }
 589
 590         /* Configure next request */
 591         if (!to_terminate)
 592                 tdc_configure_next_head_desc(tdc);
 593         return true;
 594 }
 595
 596 static void handle_once_dma_done(struct tegra_dma_channel *tdc,
 597         bool to_terminate)
 598 {
 599         struct tegra_dma_sg_req *sgreq;
 600         struct tegra_dma_desc *dma_desc;
 601
 602         tdc->busy = false;
 603         sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
 604         dma_desc = sgreq->dma_desc;
 605         dma_desc->bytes_transferred += sgreq->req_len;
 606
 607         list_del(&sgreq->node);
 608         if (sgreq->last_sg) {
 609                 dma_desc->dma_status = DMA_COMPLETE;
 610                 dma_cookie_complete(&dma_desc->txd);
 611                 if (!dma_desc->cb_count)
 612                         list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
 613                 dma_desc->cb_count++;
 614                 list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
 615         }
 616         list_add_tail(&sgreq->node, &tdc->free_sg_req);
 617
 618         /* Do not start DMA if it is going to be terminate */
 619         if (to_terminate || list_empty(&tdc->pending_sg_req))
 620                 return;
 621
 622         tdc_start_head_req(tdc);
 623 }
 624
 625 static void handle_cont_sngl_cycle_dma_done(struct tegra_dma_channel *tdc,
 626                 bool to_terminate)
 627 {
 628         struct tegra_dma_sg_req *sgreq;
 629         struct tegra_dma_desc *dma_desc;
 630         bool st;
 631
 632         sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
 633         dma_desc = sgreq->dma_desc;
 634         /* if we dma for long enough the transfer count will wrap */
 635         dma_desc->bytes_transferred =
 636                 (dma_desc->bytes_transferred + sgreq->req_len) %
 637                 dma_desc->bytes_requested;
 638
 639         /* Callback need to be call */
 640         if (!dma_desc->cb_count)
 641                 list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
 642         dma_desc->cb_count++;
 643
 644         sgreq->words_xferred = 0;
 645
 646         /* If not last req then put at end of pending list */
 647         if (!list_is_last(&sgreq->node, &tdc->pending_sg_req)) {
 648                 list_move_tail(&sgreq->node, &tdc->pending_sg_req);
 649                 sgreq->configured = false;
 650                 st = handle_continuous_head_request(tdc, sgreq, to_terminate);
 651                 if (!st)
 652                         dma_desc->dma_status = DMA_ERROR;
 653         }
 654 }
 655
 656 static void tegra_dma_tasklet(unsigned long data)
 657 {
 658         struct tegra_dma_channel *tdc = (struct tegra_dma_channel *)data;
 659         struct dmaengine_desc_callback cb;
 660         struct tegra_dma_desc *dma_desc;
 661         unsigned long flags;
 662         int cb_count;
 663
 664         spin_lock_irqsave(&tdc->lock, flags);
 665         while (!list_empty(&tdc->cb_desc)) {
 666                 dma_desc  = list_first_entry(&tdc->cb_desc,
 667                                         typeof(*dma_desc), cb_node);
 668                 list_del(&dma_desc->cb_node);
 669                 dmaengine_desc_get_callback(&dma_desc->txd, &cb);
 670                 cb_count = dma_desc->cb_count;
 671                 dma_desc->cb_count = 0;
 672                 trace_tegra_dma_complete_cb(&tdc->dma_chan, cb_count,
 673                                             cb.callback);
 674                 spin_unlock_irqrestore(&tdc->lock, flags);
 675                 while (cb_count--)
 676                         dmaengine_desc_callback_invoke(&cb, NULL);
 677                 spin_lock_irqsave(&tdc->lock, flags);
 678         }
 679         spin_unlock_irqrestore(&tdc->lock, flags);
 680 }
 681
 682 static irqreturn_t tegra_dma_isr(int irq, void *dev_id)
 683 {
 684         struct tegra_dma_channel *tdc = dev_id;
 685         unsigned long status;
 686         unsigned long flags;
 687
 688         spin_lock_irqsave(&tdc->lock, flags);
 689
 690         trace_tegra_dma_isr(&tdc->dma_chan, irq);
 691         status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 692         if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 693                 tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
 694                 tdc->isr_handler(tdc, false);
 695                 tasklet_schedule(&tdc->tasklet);
 696                 spin_unlock_irqrestore(&tdc->lock, flags);
 697                 return IRQ_HANDLED;
 698         }
 699
 700         spin_unlock_irqrestore(&tdc->lock, flags);
 701         dev_info(tdc2dev(tdc),
 702                 "Interrupt already served status 0x%08lx\n", status);
 703         return IRQ_NONE;
 704 }
 705
 706 static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *txd)
 707 {
 708         struct tegra_dma_desc *dma_desc = txd_to_tegra_dma_desc(txd);
 709         struct tegra_dma_channel *tdc = to_tegra_dma_chan(txd->chan);
 710         unsigned long flags;
 711         dma_cookie_t cookie;
 712
 713         spin_lock_irqsave(&tdc->lock, flags);
 714         dma_desc->dma_status = DMA_IN_PROGRESS;
 715         cookie = dma_cookie_assign(&dma_desc->txd);
 716         list_splice_tail_init(&dma_desc->tx_list, &tdc->pending_sg_req);
 717         spin_unlock_irqrestore(&tdc->lock, flags);
 718         return cookie;
 719 }
 720
 721 static void tegra_dma_issue_pending(struct dma_chan *dc)
 722 {
 723         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 724         unsigned long flags;
 725
 726         spin_lock_irqsave(&tdc->lock, flags);
 727         if (list_empty(&tdc->pending_sg_req)) {
 728                 dev_err(tdc2dev(tdc), "No DMA request\n");
 729                 goto end;
 730         }
 731         if (!tdc->busy) {
 732                 tdc_start_head_req(tdc);
 733
 734                 /* Continuous single mode: Configure next req */
 735                 if (tdc->cyclic) {
 736                         /*
 737                          * Wait for 1 burst time for configure DMA for
 738                          * next transfer.
 739                          */
 740                         udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
 741                         tdc_configure_next_head_desc(tdc);
 742                 }
 743         }
 744 end:
 745         spin_unlock_irqrestore(&tdc->lock, flags);
 746 }
 747
 748 static int tegra_dma_terminate_all(struct dma_chan *dc)
 749 {
 750         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 751         struct tegra_dma_sg_req *sgreq;
 752         struct tegra_dma_desc *dma_desc;
 753         unsigned long flags;
 754         unsigned long status;
 755         unsigned long wcount;
 756         bool was_busy;
 757
 758         spin_lock_irqsave(&tdc->lock, flags);
 759
 760         if (!tdc->busy)
 761                 goto skip_dma_stop;
 762
 763         /* Pause DMA before checking the queue status */
 764         tegra_dma_pause(tdc, true);
 765
 766         status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 767         if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 768                 dev_dbg(tdc2dev(tdc), "%s():handling isr\n", __func__);
 769                 tdc->isr_handler(tdc, true);
 770                 status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 771         }
 772         if (tdc->tdma->chip_data->support_separate_wcount_reg)
 773                 wcount = tdc_read(tdc, TEGRA_APBDMA_CHAN_WORD_TRANSFER);
 774         else
 775                 wcount = status;
 776
 777         was_busy = tdc->busy;
 778         tegra_dma_stop(tdc);
 779
 780         if (!list_empty(&tdc->pending_sg_req) && was_busy) {
 781                 sgreq = list_first_entry(&tdc->pending_sg_req,
 782                                         typeof(*sgreq), node);
 783                 sgreq->dma_desc->bytes_transferred +=
 784                                 get_current_xferred_count(tdc, sgreq, wcount);
 785         }
 786         tegra_dma_resume(tdc);
 787
 788 skip_dma_stop:
 789         tegra_dma_abort_all(tdc);
 790
 791         while (!list_empty(&tdc->cb_desc)) {
 792                 dma_desc  = list_first_entry(&tdc->cb_desc,
 793                                         typeof(*dma_desc), cb_node);
 794                 list_del(&dma_desc->cb_node);
 795                 dma_desc->cb_count = 0;
 796         }
 797         spin_unlock_irqrestore(&tdc->lock, flags);
 798         return 0;
 799 }
 800
 801 static unsigned int tegra_dma_sg_bytes_xferred(struct tegra_dma_channel *tdc,
 802                                                struct tegra_dma_sg_req *sg_req)
 803 {
 804         unsigned long status, wcount = 0;
 805
 806         if (!list_is_first(&sg_req->node, &tdc->pending_sg_req))
 807                 return 0;
 808
 809         if (tdc->tdma->chip_data->support_separate_wcount_reg)
 810                 wcount = tdc_read(tdc, TEGRA_APBDMA_CHAN_WORD_TRANSFER);
 811
 812         status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 813
 814         if (!tdc->tdma->chip_data->support_separate_wcount_reg)
 815                 wcount = status;
 816
 817         if (status & TEGRA_APBDMA_STATUS_ISE_EOC)
 818                 return sg_req->req_len;
 819
 820         wcount = get_current_xferred_count(tdc, sg_req, wcount);
 821
 822         if (!wcount) {
 823                 /*
 824                  * If wcount wasn't ever polled for this SG before, then
 825                  * simply assume that transfer hasn't started yet.
 826                  *
 827                  * Otherwise it's the end of the transfer.
 828                  *
 829                  * The alternative would be to poll the status register
 830                  * until EOC bit is set or wcount goes UP. That's so
 831                  * because EOC bit is getting set only after the last
 832                  * burst's completion and counter is less than the actual
 833                  * transfer size by 4 bytes. The counter value wraps around
 834                  * in a cyclic mode before EOC is set(!), so we can't easily
 835                  * distinguish start of transfer from its end.
 836                  */
 837                 if (sg_req->words_xferred)
 838                         wcount = sg_req->req_len - 4;
 839
 840         } else if (wcount < sg_req->words_xferred) {
 841                 /*
 842                  * This case will never happen for a non-cyclic transfer.
 843                  *
 844                  * For a cyclic transfer, although it is possible for the
 845                  * next transfer to have already started (resetting the word
 846                  * count), this case should still not happen because we should
 847                  * have detected that the EOC bit is set and hence the transfer
 848                  * was completed.
 849                  */
 850                 WARN_ON_ONCE(1);
 851
 852                 wcount = sg_req->req_len - 4;
 853         } else {
 854                 sg_req->words_xferred = wcount;
 855         }
 856
 857         return wcount;
 858 }
 859
 860 static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
 861         dma_cookie_t cookie, struct dma_tx_state *txstate)
 862 {
 863         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 864         struct tegra_dma_desc *dma_desc;
 865         struct tegra_dma_sg_req *sg_req;
 866         enum dma_status ret;
 867         unsigned long flags;
 868         unsigned int residual;
 869         unsigned int bytes = 0;
 870
 871         ret = dma_cookie_status(dc, cookie, txstate);
 872         if (ret == DMA_COMPLETE)
 873                 return ret;
 874
 875         spin_lock_irqsave(&tdc->lock, flags);
 876
 877         /* Check on wait_ack desc status */
 878         list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
 879                 if (dma_desc->txd.cookie == cookie) {
 880                         ret = dma_desc->dma_status;
 881                         goto found;
 882                 }
 883         }
 884
 885         /* Check in pending list */
 886         list_for_each_entry(sg_req, &tdc->pending_sg_req, node) {
 887                 dma_desc = sg_req->dma_desc;
 888                 if (dma_desc->txd.cookie == cookie) {
 889                         bytes = tegra_dma_sg_bytes_xferred(tdc, sg_req);
 890                         ret = dma_desc->dma_status;
 891                         goto found;
 892                 }
 893         }
 894
 895         dev_dbg(tdc2dev(tdc), "cookie %d not found\n", cookie);
 896         dma_desc = NULL;
 897
 898 found:
 899         if (dma_desc && txstate) {
 900                 residual = dma_desc->bytes_requested -
 901                            ((dma_desc->bytes_transferred + bytes) %
 902                             dma_desc->bytes_requested);
 903                 dma_set_residue(txstate, residual);
 904         }
 905
 906         trace_tegra_dma_tx_status(&tdc->dma_chan, cookie, txstate);
 907         spin_unlock_irqrestore(&tdc->lock, flags);
 908         return ret;
 909 }
 910
 911 static inline int get_bus_width(struct tegra_dma_channel *tdc,
 912                 enum dma_slave_buswidth slave_bw)
 913 {
 914         switch (slave_bw) {
 915         case DMA_SLAVE_BUSWIDTH_1_BYTE:
 916                 return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_8;
 917         case DMA_SLAVE_BUSWIDTH_2_BYTES:
 918                 return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_16;
 919         case DMA_SLAVE_BUSWIDTH_4_BYTES:
 920                 return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32;
 921         case DMA_SLAVE_BUSWIDTH_8_BYTES:
 922                 return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_64;
 923         default:
 924                 dev_warn(tdc2dev(tdc),
 925                         "slave bw is not supported, using 32bits\n");
 926                 return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32;
 927         }
 928 }
 929
 930 static inline int get_burst_size(struct tegra_dma_channel *tdc,
 931         u32 burst_size, enum dma_slave_buswidth slave_bw, int len)
 932 {
 933         int burst_byte;
 934         int burst_ahb_width;
 935
 936         /*
 937          * burst_size from client is in terms of the bus_width.
 938          * convert them into AHB memory width which is 4 byte.
 939          */
 940         burst_byte = burst_size * slave_bw;
 941         burst_ahb_width = burst_byte / 4;
 942
 943         /* If burst size is 0 then calculate the burst size based on length */
 944         if (!burst_ahb_width) {
 945                 if (len & 0xF)
 946                         return TEGRA_APBDMA_AHBSEQ_BURST_1;
 947                 else if ((len >> 4) & 0x1)
 948                         return TEGRA_APBDMA_AHBSEQ_BURST_4;
 949                 else
 950                         return TEGRA_APBDMA_AHBSEQ_BURST_8;
 951         }
 952         if (burst_ahb_width < 4)
 953                 return TEGRA_APBDMA_AHBSEQ_BURST_1;
 954         else if (burst_ahb_width < 8)
 955                 return TEGRA_APBDMA_AHBSEQ_BURST_4;
 956         else
 957                 return TEGRA_APBDMA_AHBSEQ_BURST_8;
 958 }
 959
 960 static int get_transfer_param(struct tegra_dma_channel *tdc,
 961         enum dma_transfer_direction direction, unsigned long *apb_addr,
 962         unsigned long *apb_seq, unsigned long *csr, unsigned int *burst_size,
 963         enum dma_slave_buswidth *slave_bw)
 964 {
 965         switch (direction) {
 966         case DMA_MEM_TO_DEV:
 967                 *apb_addr = tdc->dma_sconfig.dst_addr;
 968                 *apb_seq = get_bus_width(tdc, tdc->dma_sconfig.dst_addr_width);
 969                 *burst_size = tdc->dma_sconfig.dst_maxburst;
 970                 *slave_bw = tdc->dma_sconfig.dst_addr_width;
 971                 *csr = TEGRA_APBDMA_CSR_DIR;
 972                 return 0;
 973
 974         case DMA_DEV_TO_MEM:
 975                 *apb_addr = tdc->dma_sconfig.src_addr;
 976                 *apb_seq = get_bus_width(tdc, tdc->dma_sconfig.src_addr_width);
 977                 *burst_size = tdc->dma_sconfig.src_maxburst;
 978                 *slave_bw = tdc->dma_sconfig.src_addr_width;
 979                 *csr = 0;
 980                 return 0;
 981
 982         default:
 983                 dev_err(tdc2dev(tdc), "DMA direction is not supported\n");
 984                 return -EINVAL;
 985         }
 986         return -EINVAL;
 987 }
 988
 989 static void tegra_dma_prep_wcount(struct tegra_dma_channel *tdc,
 990         struct tegra_dma_channel_regs *ch_regs, u32 len)
 991 {
 992         u32 len_field = (len - 4) & 0xFFFC;
 993
 994         if (tdc->tdma->chip_data->support_separate_wcount_reg)
 995                 ch_regs->wcount = len_field;
 996         else
 997                 ch_regs->csr |= len_field;
 998 }
 999
1000 static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg(
1001         struct dma_chan *dc, struct scatterlist *sgl, unsigned int sg_len,
1002         enum dma_transfer_direction direction, unsigned long flags,
1003         void *context)
1004 {
1005         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1006         struct tegra_dma_desc *dma_desc;
1007         unsigned int i;
1008         struct scatterlist *sg;
1009         unsigned long csr, ahb_seq, apb_ptr, apb_seq;
1010         struct list_head req_list;
1011         struct tegra_dma_sg_req  *sg_req = NULL;
1012         u32 burst_size;
1013         enum dma_slave_buswidth slave_bw;
1014
1015         if (!tdc->config_init) {
1016                 dev_err(tdc2dev(tdc), "DMA channel is not configured\n");
1017                 return NULL;
1018         }
1019         if (sg_len < 1) {
1020                 dev_err(tdc2dev(tdc), "Invalid segment length %d\n", sg_len);
1021                 return NULL;
1022         }
1023
1024         if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
1025                                 &burst_size, &slave_bw) < 0)
1026                 return NULL;
1027
1028         INIT_LIST_HEAD(&req_list);
1029
1030         ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
1031         ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
1032                                         TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
1033         ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
1034
1035         csr |= TEGRA_APBDMA_CSR_ONCE;
1036
1037         if (tdc->slave_id != TEGRA_APBDMA_SLAVE_ID_INVALID) {
1038                 csr |= TEGRA_APBDMA_CSR_FLOW;
1039                 csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
1040         }
1041
1042         if (flags & DMA_PREP_INTERRUPT) {
1043                 csr |= TEGRA_APBDMA_CSR_IE_EOC;
1044         } else {
1045                 WARN_ON_ONCE(1);
1046                 return NULL;
1047         }
1048
1049         apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
1050
1051         dma_desc = tegra_dma_desc_get(tdc);
1052         if (!dma_desc) {
1053                 dev_err(tdc2dev(tdc), "DMA descriptors not available\n");
1054                 return NULL;
1055         }
1056         INIT_LIST_HEAD(&dma_desc->tx_list);
1057         INIT_LIST_HEAD(&dma_desc->cb_node);
1058         dma_desc->cb_count = 0;
1059         dma_desc->bytes_requested = 0;
1060         dma_desc->bytes_transferred = 0;
1061         dma_desc->dma_status = DMA_IN_PROGRESS;
1062
1063         /* Make transfer requests */
1064         for_each_sg(sgl, sg, sg_len, i) {
1065                 u32 len, mem;
1066
1067                 mem = sg_dma_address(sg);
1068                 len = sg_dma_len(sg);
1069
1070                 if ((len & 3) || (mem & 3) ||
1071                                 (len > tdc->tdma->chip_data->max_dma_count)) {
1072                         dev_err(tdc2dev(tdc),
1073                                 "DMA length/memory address is not supported\n");
1074                         tegra_dma_desc_put(tdc, dma_desc);
1075                         return NULL;
1076                 }
1077
1078                 sg_req = tegra_dma_sg_req_get(tdc);
1079                 if (!sg_req) {
1080                         dev_err(tdc2dev(tdc), "DMA sg-req not available\n");
1081                         tegra_dma_desc_put(tdc, dma_desc);
1082                         return NULL;
1083                 }
1084
1085                 ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
1086                 dma_desc->bytes_requested += len;
1087
1088                 sg_req->ch_regs.apb_ptr = apb_ptr;
1089                 sg_req->ch_regs.ahb_ptr = mem;
1090                 sg_req->ch_regs.csr = csr;
1091                 tegra_dma_prep_wcount(tdc, &sg_req->ch_regs, len);
1092                 sg_req->ch_regs.apb_seq = apb_seq;
1093                 sg_req->ch_regs.ahb_seq = ahb_seq;
1094                 sg_req->configured = false;
1095                 sg_req->last_sg = false;
1096                 sg_req->dma_desc = dma_desc;
1097                 sg_req->req_len = len;
1098
1099                 list_add_tail(&sg_req->node, &dma_desc->tx_list);
1100         }
1101         sg_req->last_sg = true;
1102         if (flags & DMA_CTRL_ACK)
1103                 dma_desc->txd.flags = DMA_CTRL_ACK;
1104
1105         /*
1106          * Make sure that mode should not be conflicting with currently
1107          * configured mode.
1108          */
1109         if (!tdc->isr_handler) {
1110                 tdc->isr_handler = handle_once_dma_done;
1111                 tdc->cyclic = false;
1112         } else {
1113                 if (tdc->cyclic) {
1114                         dev_err(tdc2dev(tdc), "DMA configured in cyclic mode\n");
1115                         tegra_dma_desc_put(tdc, dma_desc);
1116                         return NULL;
1117                 }
1118         }
1119
1120         return &dma_desc->txd;
1121 }
1122
1123 static struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic(
1124         struct dma_chan *dc, dma_addr_t buf_addr, size_t buf_len,
1125         size_t period_len, enum dma_transfer_direction direction,
1126         unsigned long flags)
1127 {
1128         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1129         struct tegra_dma_desc *dma_desc = NULL;
1130         struct tegra_dma_sg_req *sg_req = NULL;
1131         unsigned long csr, ahb_seq, apb_ptr, apb_seq;
1132         int len;
1133         size_t remain_len;
1134         dma_addr_t mem = buf_addr;
1135         u32 burst_size;
1136         enum dma_slave_buswidth slave_bw;
1137
1138         if (!buf_len || !period_len) {
1139                 dev_err(tdc2dev(tdc), "Invalid buffer/period len\n");
1140                 return NULL;
1141         }
1142
1143         if (!tdc->config_init) {
1144                 dev_err(tdc2dev(tdc), "DMA slave is not configured\n");
1145                 return NULL;
1146         }
1147
1148         /*
1149          * We allow to take more number of requests till DMA is
1150          * not started. The driver will loop over all requests.
1151          * Once DMA is started then new requests can be queued only after
1152          * terminating the DMA.
1153          */
1154         if (tdc->busy) {
1155                 dev_err(tdc2dev(tdc), "Request not allowed when DMA running\n");
1156                 return NULL;
1157         }
1158
1159         /*
1160          * We only support cycle transfer when buf_len is multiple of
1161          * period_len.
1162          */
1163         if (buf_len % period_len) {
1164                 dev_err(tdc2dev(tdc), "buf_len is not multiple of period_len\n");
1165                 return NULL;
1166         }
1167
1168         len = period_len;
1169         if ((len & 3) || (buf_addr & 3) ||
1170                         (len > tdc->tdma->chip_data->max_dma_count)) {
1171                 dev_err(tdc2dev(tdc), "Req len/mem address is not correct\n");
1172                 return NULL;
1173         }
1174
1175         if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
1176                                 &burst_size, &slave_bw) < 0)
1177                 return NULL;
1178
1179         ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
1180         ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
1181                                         TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
1182         ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
1183
1184         if (tdc->slave_id != TEGRA_APBDMA_SLAVE_ID_INVALID) {
1185                 csr |= TEGRA_APBDMA_CSR_FLOW;
1186                 csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
1187         }
1188
1189         if (flags & DMA_PREP_INTERRUPT) {
1190                 csr |= TEGRA_APBDMA_CSR_IE_EOC;
1191         } else {
1192                 WARN_ON_ONCE(1);
1193                 return NULL;
1194         }
1195
1196         apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
1197
1198         dma_desc = tegra_dma_desc_get(tdc);
1199         if (!dma_desc) {
1200                 dev_err(tdc2dev(tdc), "not enough descriptors available\n");
1201                 return NULL;
1202         }
1203
1204         INIT_LIST_HEAD(&dma_desc->tx_list);
1205         INIT_LIST_HEAD(&dma_desc->cb_node);
1206         dma_desc->cb_count = 0;
1207
1208         dma_desc->bytes_transferred = 0;
1209         dma_desc->bytes_requested = buf_len;
1210         remain_len = buf_len;
1211
1212         /* Split transfer equal to period size */
1213         while (remain_len) {
1214                 sg_req = tegra_dma_sg_req_get(tdc);
1215                 if (!sg_req) {
1216                         dev_err(tdc2dev(tdc), "DMA sg-req not available\n");
1217                         tegra_dma_desc_put(tdc, dma_desc);
1218                         return NULL;
1219                 }
1220
1221                 ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
1222                 sg_req->ch_regs.apb_ptr = apb_ptr;
1223                 sg_req->ch_regs.ahb_ptr = mem;
1224                 sg_req->ch_regs.csr = csr;
1225                 tegra_dma_prep_wcount(tdc, &sg_req->ch_regs, len);
1226                 sg_req->ch_regs.apb_seq = apb_seq;
1227                 sg_req->ch_regs.ahb_seq = ahb_seq;
1228                 sg_req->configured = false;
1229                 sg_req->last_sg = false;
1230                 sg_req->dma_desc = dma_desc;
1231                 sg_req->req_len = len;
1232
1233                 list_add_tail(&sg_req->node, &dma_desc->tx_list);
1234                 remain_len -= len;
1235                 mem += len;
1236         }
1237         sg_req->last_sg = true;
1238         if (flags & DMA_CTRL_ACK)
1239                 dma_desc->txd.flags = DMA_CTRL_ACK;
1240
1241         /*
1242          * Make sure that mode should not be conflicting with currently
1243          * configured mode.
1244          */
1245         if (!tdc->isr_handler) {
1246                 tdc->isr_handler = handle_cont_sngl_cycle_dma_done;
1247                 tdc->cyclic = true;
1248         } else {
1249                 if (!tdc->cyclic) {
1250                         dev_err(tdc2dev(tdc), "DMA configuration conflict\n");
1251                         tegra_dma_desc_put(tdc, dma_desc);
1252                         return NULL;
1253                 }
1254         }
1255
1256         return &dma_desc->txd;
1257 }
1258
1259 static int tegra_dma_alloc_chan_resources(struct dma_chan *dc)
1260 {
1261         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1262         struct tegra_dma *tdma = tdc->tdma;
1263         int ret;
1264
1265         dma_cookie_init(&tdc->dma_chan);
1266         tdc->config_init = false;
1267
1268         ret = pm_runtime_get_sync(tdma->dev);
1269         if (ret < 0)
1270                 return ret;
1271
1272         return 0;
1273 }
1274
1275 static void tegra_dma_free_chan_resources(struct dma_chan *dc)
1276 {
1277         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1278         struct tegra_dma *tdma = tdc->tdma;
1279         struct tegra_dma_desc *dma_desc;
1280         struct tegra_dma_sg_req *sg_req;
1281         struct list_head dma_desc_list;
1282         struct list_head sg_req_list;
1283         unsigned long flags;
1284
1285         INIT_LIST_HEAD(&dma_desc_list);
1286         INIT_LIST_HEAD(&sg_req_list);
1287
1288         dev_dbg(tdc2dev(tdc), "Freeing channel %d\n", tdc->id);
1289
1290         tegra_dma_terminate_all(dc);
1291
1292         spin_lock_irqsave(&tdc->lock, flags);
1293         list_splice_init(&tdc->pending_sg_req, &sg_req_list);
1294         list_splice_init(&tdc->free_sg_req, &sg_req_list);
1295         list_splice_init(&tdc->free_dma_desc, &dma_desc_list);
1296         INIT_LIST_HEAD(&tdc->cb_desc);
1297         tdc->config_init = false;
1298         tdc->isr_handler = NULL;
1299         spin_unlock_irqrestore(&tdc->lock, flags);
1300
1301         while (!list_empty(&dma_desc_list)) {
1302                 dma_desc = list_first_entry(&dma_desc_list,
1303                                         typeof(*dma_desc), node);
1304                 list_del(&dma_desc->node);
1305                 kfree(dma_desc);
1306         }
1307
1308         while (!list_empty(&sg_req_list)) {
1309                 sg_req = list_first_entry(&sg_req_list, typeof(*sg_req), node);
1310                 list_del(&sg_req->node);
1311                 kfree(sg_req);
1312         }
1313         pm_runtime_put(tdma->dev);
1314
1315         tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
1316 }
1317
1318 static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
1319                                            struct of_dma *ofdma)
1320 {
1321         struct tegra_dma *tdma = ofdma->of_dma_data;
1322         struct dma_chan *chan;
1323         struct tegra_dma_channel *tdc;
1324
1325         if (dma_spec->args[0] > TEGRA_APBDMA_CSR_REQ_SEL_MASK) {
1326                 dev_err(tdma->dev, "Invalid slave id: %d\n", dma_spec->args[0]);
1327                 return NULL;
1328         }
1329
1330         chan = dma_get_any_slave_channel(&tdma->dma_dev);
1331         if (!chan)
1332                 return NULL;
1333
1334         tdc = to_tegra_dma_chan(chan);
1335         tdc->slave_id = dma_spec->args[0];
1336
1337         return chan;
1338 }
1339
1340 /* Tegra20 specific DMA controller information */
1341 static const struct tegra_dma_chip_data tegra20_dma_chip_data = {
1342         .nr_channels            = 16,
1343         .channel_reg_size       = 0x20,
1344         .max_dma_count          = 1024UL * 64,
1345         .support_channel_pause  = false,
1346         .support_separate_wcount_reg = false,
1347 };
1348
1349 /* Tegra30 specific DMA controller information */
1350 static const struct tegra_dma_chip_data tegra30_dma_chip_data = {
1351         .nr_channels            = 32,
1352         .channel_reg_size       = 0x20,
1353         .max_dma_count          = 1024UL * 64,
1354         .support_channel_pause  = false,
1355         .support_separate_wcount_reg = false,
1356 };
1357
1358 /* Tegra114 specific DMA controller information */
1359 static const struct tegra_dma_chip_data tegra114_dma_chip_data = {
1360         .nr_channels            = 32,
1361         .channel_reg_size       = 0x20,
1362         .max_dma_count          = 1024UL * 64,
1363         .support_channel_pause  = true,
1364         .support_separate_wcount_reg = false,
1365 };
1366
1367 /* Tegra148 specific DMA controller information */
1368 static const struct tegra_dma_chip_data tegra148_dma_chip_data = {
1369         .nr_channels            = 32,
1370         .channel_reg_size       = 0x40,
1371         .max_dma_count          = 1024UL * 64,
1372         .support_channel_pause  = true,
1373         .support_separate_wcount_reg = true,
1374 };
1375
1376 static int tegra_dma_probe(struct platform_device *pdev)
1377 {
1378         struct resource *res;
1379         struct tegra_dma *tdma;
1380         int ret;
1381         int i;
1382         const struct tegra_dma_chip_data *cdata;
1383
1384         cdata = of_device_get_match_data(&pdev->dev);
1385         if (!cdata) {
1386                 dev_err(&pdev->dev, "Error: No device match data found\n");
1387                 return -ENODEV;
1388         }
1389
1390         tdma = devm_kzalloc(&pdev->dev,
1391                             struct_size(tdma, channels, cdata->nr_channels),
1392                             GFP_KERNEL);
1393         if (!tdma)
1394                 return -ENOMEM;
1395
1396         tdma->dev = &pdev->dev;
1397         tdma->chip_data = cdata;
1398         platform_set_drvdata(pdev, tdma);
1399
1400         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1401         tdma->base_addr = devm_ioremap_resource(&pdev->dev, res);
1402         if (IS_ERR(tdma->base_addr))
1403                 return PTR_ERR(tdma->base_addr);
1404
1405         tdma->dma_clk = devm_clk_get(&pdev->dev, NULL);
1406         if (IS_ERR(tdma->dma_clk)) {
1407                 dev_err(&pdev->dev, "Error: Missing controller clock\n");
1408                 return PTR_ERR(tdma->dma_clk);
1409         }
1410
1411         tdma->rst = devm_reset_control_get(&pdev->dev, "dma");
1412         if (IS_ERR(tdma->rst)) {
1413                 dev_err(&pdev->dev, "Error: Missing reset\n");
1414                 return PTR_ERR(tdma->rst);
1415         }
1416
1417         spin_lock_init(&tdma->global_lock);
1418
1419         pm_runtime_enable(&pdev->dev);
1420         if (!pm_runtime_enabled(&pdev->dev))
1421                 ret = tegra_dma_runtime_resume(&pdev->dev);
1422         else
1423                 ret = pm_runtime_get_sync(&pdev->dev);
1424
1425         if (ret < 0) {
1426                 pm_runtime_disable(&pdev->dev);
1427                 return ret;
1428         }
1429
1430         /* Reset DMA controller */
1431         reset_control_assert(tdma->rst);
1432         udelay(2);
1433         reset_control_deassert(tdma->rst);
1434
1435         /* Enable global DMA registers */
1436         tdma_write(tdma, TEGRA_APBDMA_GENERAL, TEGRA_APBDMA_GENERAL_ENABLE);
1437         tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
1438         tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFFul);
1439
1440         pm_runtime_put(&pdev->dev);
1441
1442         INIT_LIST_HEAD(&tdma->dma_dev.channels);
1443         for (i = 0; i < cdata->nr_channels; i++) {
1444                 struct tegra_dma_channel *tdc = &tdma->channels[i];
1445
1446                 tdc->chan_addr = tdma->base_addr +
1447                                  TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET +
1448                                  (i * cdata->channel_reg_size);
1449
1450                 res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
1451                 if (!res) {
1452                         ret = -EINVAL;
1453                         dev_err(&pdev->dev, "No irq resource for chan %d\n", i);
1454                         goto err_irq;
1455                 }
1456                 tdc->irq = res->start;
1457                 snprintf(tdc->name, sizeof(tdc->name), "apbdma.%d", i);
1458                 ret = request_irq(tdc->irq, tegra_dma_isr, 0, tdc->name, tdc);
1459                 if (ret) {
1460                         dev_err(&pdev->dev,
1461                                 "request_irq failed with err %d channel %d\n",
1462                                 ret, i);
1463                         goto err_irq;
1464                 }
1465
1466                 tdc->dma_chan.device = &tdma->dma_dev;
1467                 dma_cookie_init(&tdc->dma_chan);
1468                 list_add_tail(&tdc->dma_chan.device_node,
1469                                 &tdma->dma_dev.channels);
1470                 tdc->tdma = tdma;
1471                 tdc->id = i;
1472                 tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
1473
1474                 tasklet_init(&tdc->tasklet, tegra_dma_tasklet,
1475                                 (unsigned long)tdc);
1476                 spin_lock_init(&tdc->lock);
1477
1478                 INIT_LIST_HEAD(&tdc->pending_sg_req);
1479                 INIT_LIST_HEAD(&tdc->free_sg_req);
1480                 INIT_LIST_HEAD(&tdc->free_dma_desc);
1481                 INIT_LIST_HEAD(&tdc->cb_desc);
1482         }
1483
1484         dma_cap_set(DMA_SLAVE, tdma->dma_dev.cap_mask);
1485         dma_cap_set(DMA_PRIVATE, tdma->dma_dev.cap_mask);
1486         dma_cap_set(DMA_CYCLIC, tdma->dma_dev.cap_mask);
1487
1488         tdma->global_pause_count = 0;
1489         tdma->dma_dev.dev = &pdev->dev;
1490         tdma->dma_dev.device_alloc_chan_resources =
1491                                         tegra_dma_alloc_chan_resources;
1492         tdma->dma_dev.device_free_chan_resources =
1493                                         tegra_dma_free_chan_resources;
1494         tdma->dma_dev.device_prep_slave_sg = tegra_dma_prep_slave_sg;
1495         tdma->dma_dev.device_prep_dma_cyclic = tegra_dma_prep_dma_cyclic;
1496         tdma->dma_dev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1497                 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1498                 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1499                 BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1500         tdma->dma_dev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1501                 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1502                 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1503                 BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1504         tdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1505         tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1506         tdma->dma_dev.device_config = tegra_dma_slave_config;
1507         tdma->dma_dev.device_terminate_all = tegra_dma_terminate_all;
1508         tdma->dma_dev.device_tx_status = tegra_dma_tx_status;
1509         tdma->dma_dev.device_issue_pending = tegra_dma_issue_pending;
1510
1511         ret = dma_async_device_register(&tdma->dma_dev);
1512         if (ret < 0) {
1513                 dev_err(&pdev->dev,
1514                         "Tegra20 APB DMA driver registration failed %d\n", ret);
1515                 goto err_irq;
1516         }
1517
1518         ret = of_dma_controller_register(pdev->dev.of_node,
1519                                          tegra_dma_of_xlate, tdma);
1520         if (ret < 0) {
1521                 dev_err(&pdev->dev,
1522                         "Tegra20 APB DMA OF registration failed %d\n", ret);
1523                 goto err_unregister_dma_dev;
1524         }
1525
1526         dev_info(&pdev->dev, "Tegra20 APB DMA driver register %d channels\n",
1527                         cdata->nr_channels);
1528         return 0;
1529
1530 err_unregister_dma_dev:
1531         dma_async_device_unregister(&tdma->dma_dev);
1532 err_irq:
1533         while (--i >= 0) {
1534                 struct tegra_dma_channel *tdc = &tdma->channels[i];
1535
1536                 free_irq(tdc->irq, tdc);
1537                 tasklet_kill(&tdc->tasklet);
1538         }
1539
1540         pm_runtime_disable(&pdev->dev);
1541         if (!pm_runtime_status_suspended(&pdev->dev))
1542                 tegra_dma_runtime_suspend(&pdev->dev);
1543         return ret;
1544 }
1545
1546 static int tegra_dma_remove(struct platform_device *pdev)
1547 {
1548         struct tegra_dma *tdma = platform_get_drvdata(pdev);
1549         int i;
1550         struct tegra_dma_channel *tdc;
1551
1552         dma_async_device_unregister(&tdma->dma_dev);
1553
1554         for (i = 0; i < tdma->chip_data->nr_channels; ++i) {
1555                 tdc = &tdma->channels[i];
1556                 free_irq(tdc->irq, tdc);
1557                 tasklet_kill(&tdc->tasklet);
1558         }
1559
1560         pm_runtime_disable(&pdev->dev);
1561         if (!pm_runtime_status_suspended(&pdev->dev))
1562                 tegra_dma_runtime_suspend(&pdev->dev);
1563
1564         return 0;
1565 }
1566
1567 static int tegra_dma_runtime_suspend(struct device *dev)
1568 {
1569         struct tegra_dma *tdma = dev_get_drvdata(dev);
1570         int i;
1571
1572         tdma->reg_gen = tdma_read(tdma, TEGRA_APBDMA_GENERAL);
1573         for (i = 0; i < tdma->chip_data->nr_channels; i++) {
1574                 struct tegra_dma_channel *tdc = &tdma->channels[i];
1575                 struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
1576
1577                 /* Only save the state of DMA channels that are in use */
1578                 if (!tdc->config_init)
1579                         continue;
1580
1581                 ch_reg->csr = tdc_read(tdc, TEGRA_APBDMA_CHAN_CSR);
1582                 ch_reg->ahb_ptr = tdc_read(tdc, TEGRA_APBDMA_CHAN_AHBPTR);
1583                 ch_reg->apb_ptr = tdc_read(tdc, TEGRA_APBDMA_CHAN_APBPTR);
1584                 ch_reg->ahb_seq = tdc_read(tdc, TEGRA_APBDMA_CHAN_AHBSEQ);
1585                 ch_reg->apb_seq = tdc_read(tdc, TEGRA_APBDMA_CHAN_APBSEQ);
1586                 if (tdma->chip_data->support_separate_wcount_reg)
1587                         ch_reg->wcount = tdc_read(tdc,
1588                                                   TEGRA_APBDMA_CHAN_WCOUNT);
1589         }
1590
1591         clk_disable_unprepare(tdma->dma_clk);
1592
1593         return 0;
1594 }
1595
1596 static int tegra_dma_runtime_resume(struct device *dev)
1597 {
1598         struct tegra_dma *tdma = dev_get_drvdata(dev);
1599         int i, ret;
1600
1601         ret = clk_prepare_enable(tdma->dma_clk);
1602         if (ret < 0) {
1603                 dev_err(dev, "clk_enable failed: %d\n", ret);
1604                 return ret;
1605         }
1606
1607         tdma_write(tdma, TEGRA_APBDMA_GENERAL, tdma->reg_gen);
1608         tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
1609         tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFFul);
1610
1611         for (i = 0; i < tdma->chip_data->nr_channels; i++) {
1612                 struct tegra_dma_channel *tdc = &tdma->channels[i];
1613                 struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
1614
1615                 /* Only restore the state of DMA channels that are in use */
1616                 if (!tdc->config_init)
1617                         continue;
1618
1619                 if (tdma->chip_data->support_separate_wcount_reg)
1620                         tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT,
1621                                   ch_reg->wcount);
1622                 tdc_write(tdc, TEGRA_APBDMA_CHAN_APBSEQ, ch_reg->apb_seq);
1623                 tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, ch_reg->apb_ptr);
1624                 tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBSEQ, ch_reg->ahb_seq);
1625                 tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, ch_reg->ahb_ptr);
1626                 tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
1627                         (ch_reg->csr & ~TEGRA_APBDMA_CSR_ENB));
1628         }
1629
1630         return 0;
1631 }
1632
1633 static const struct dev_pm_ops tegra_dma_dev_pm_ops = {
1634         SET_RUNTIME_PM_OPS(tegra_dma_runtime_suspend, tegra_dma_runtime_resume,
1635                            NULL)
1636         SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
1637                                 pm_runtime_force_resume)
1638 };
1639
1640 static const struct of_device_id tegra_dma_of_match[] = {
1641         {
1642                 .compatible = "nvidia,tegra148-apbdma",
1643                 .data = &tegra148_dma_chip_data,
1644         }, {
1645                 .compatible = "nvidia,tegra114-apbdma",
1646                 .data = &tegra114_dma_chip_data,
1647         }, {
1648                 .compatible = "nvidia,tegra30-apbdma",
1649                 .data = &tegra30_dma_chip_data,
1650         }, {
1651                 .compatible = "nvidia,tegra20-apbdma",
1652                 .data = &tegra20_dma_chip_data,
1653         }, {
1654         },
1655 };
1656 MODULE_DEVICE_TABLE(of, tegra_dma_of_match);
1657
1658 static struct platform_driver tegra_dmac_driver = {
1659         .driver = {
1660                 .name   = "tegra-apbdma",
1661                 .pm     = &tegra_dma_dev_pm_ops,
1662                 .of_match_table = tegra_dma_of_match,
1663         },
1664         .probe          = tegra_dma_probe,
1665         .remove         = tegra_dma_remove,
1666 };
1667
1668 module_platform_driver(tegra_dmac_driver);
1669
1670 MODULE_ALIAS("platform:tegra20-apbdma");
1671 MODULE_DESCRIPTION("NVIDIA Tegra APB DMA Controller driver");
1672 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1673 MODULE_LICENSE("GPL v2");