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