linux/sound/soc/samsung/dma.c
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   1/*
   2 * dma.c  --  ALSA Soc Audio Layer
   3 *
   4 * (c) 2006 Wolfson Microelectronics PLC.
   5 * Graeme Gregory graeme.gregory@wolfsonmicro.com or linux@wolfsonmicro.com
   6 *
   7 * Copyright 2004-2005 Simtec Electronics
   8 *      http://armlinux.simtec.co.uk/
   9 *      Ben Dooks <ben@simtec.co.uk>
  10 *
  11 *  This program is free software; you can redistribute  it and/or modify it
  12 *  under  the terms of  the GNU General  Public License as published by the
  13 *  Free Software Foundation;  either version 2 of the  License, or (at your
  14 *  option) any later version.
  15 */
  16
  17#include <linux/slab.h>
  18#include <linux/dma-mapping.h>
  19#include <linux/module.h>
  20
  21#include <sound/soc.h>
  22#include <sound/pcm_params.h>
  23
  24#include <asm/dma.h>
  25#include <mach/hardware.h>
  26#include <mach/dma.h>
  27
  28#include "dma.h"
  29
  30#define ST_RUNNING              (1<<0)
  31#define ST_OPENED               (1<<1)
  32
  33static const struct snd_pcm_hardware dma_hardware = {
  34        .info                   = SNDRV_PCM_INFO_INTERLEAVED |
  35                                    SNDRV_PCM_INFO_BLOCK_TRANSFER |
  36                                    SNDRV_PCM_INFO_MMAP |
  37                                    SNDRV_PCM_INFO_MMAP_VALID,
  38        .formats                = SNDRV_PCM_FMTBIT_S16_LE |
  39                                    SNDRV_PCM_FMTBIT_U16_LE |
  40                                    SNDRV_PCM_FMTBIT_U8 |
  41                                    SNDRV_PCM_FMTBIT_S8,
  42        .channels_min           = 2,
  43        .channels_max           = 2,
  44        .buffer_bytes_max       = 128*1024,
  45        .period_bytes_min       = PAGE_SIZE,
  46        .period_bytes_max       = PAGE_SIZE*2,
  47        .periods_min            = 2,
  48        .periods_max            = 128,
  49        .fifo_size              = 32,
  50};
  51
  52struct runtime_data {
  53        spinlock_t lock;
  54        int state;
  55        unsigned int dma_loaded;
  56        unsigned int dma_period;
  57        dma_addr_t dma_start;
  58        dma_addr_t dma_pos;
  59        dma_addr_t dma_end;
  60        struct s3c_dma_params *params;
  61};
  62
  63static void audio_buffdone(void *data);
  64
  65/* dma_enqueue
  66 *
  67 * place a dma buffer onto the queue for the dma system
  68 * to handle.
  69 */
  70static void dma_enqueue(struct snd_pcm_substream *substream)
  71{
  72        struct runtime_data *prtd = substream->runtime->private_data;
  73        dma_addr_t pos = prtd->dma_pos;
  74        unsigned int limit;
  75        struct samsung_dma_prep dma_info;
  76
  77        pr_debug("Entered %s\n", __func__);
  78
  79        limit = (prtd->dma_end - prtd->dma_start) / prtd->dma_period;
  80
  81        pr_debug("%s: loaded %d, limit %d\n",
  82                                __func__, prtd->dma_loaded, limit);
  83
  84        dma_info.cap = (samsung_dma_has_circular() ? DMA_CYCLIC : DMA_SLAVE);
  85        dma_info.direction =
  86                (substream->stream == SNDRV_PCM_STREAM_PLAYBACK
  87                ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM);
  88        dma_info.fp = audio_buffdone;
  89        dma_info.fp_param = substream;
  90        dma_info.period = prtd->dma_period;
  91        dma_info.len = prtd->dma_period*limit;
  92
  93        while (prtd->dma_loaded < limit) {
  94                pr_debug("dma_loaded: %d\n", prtd->dma_loaded);
  95
  96                if ((pos + dma_info.period) > prtd->dma_end) {
  97                        dma_info.period  = prtd->dma_end - pos;
  98                        pr_debug("%s: corrected dma len %ld\n",
  99                                        __func__, dma_info.period);
 100                }
 101
 102                dma_info.buf = pos;
 103                prtd->params->ops->prepare(prtd->params->ch, &dma_info);
 104
 105                prtd->dma_loaded++;
 106                pos += prtd->dma_period;
 107                if (pos >= prtd->dma_end)
 108                        pos = prtd->dma_start;
 109        }
 110
 111        prtd->dma_pos = pos;
 112}
 113
 114static void audio_buffdone(void *data)
 115{
 116        struct snd_pcm_substream *substream = data;
 117        struct runtime_data *prtd = substream->runtime->private_data;
 118
 119        pr_debug("Entered %s\n", __func__);
 120
 121        if (prtd->state & ST_RUNNING) {
 122                prtd->dma_pos += prtd->dma_period;
 123                if (prtd->dma_pos >= prtd->dma_end)
 124                        prtd->dma_pos = prtd->dma_start;
 125
 126                if (substream)
 127                        snd_pcm_period_elapsed(substream);
 128
 129                spin_lock(&prtd->lock);
 130                if (!samsung_dma_has_circular()) {
 131                        prtd->dma_loaded--;
 132                        dma_enqueue(substream);
 133                }
 134                spin_unlock(&prtd->lock);
 135        }
 136}
 137
 138static int dma_hw_params(struct snd_pcm_substream *substream,
 139        struct snd_pcm_hw_params *params)
 140{
 141        struct snd_pcm_runtime *runtime = substream->runtime;
 142        struct runtime_data *prtd = runtime->private_data;
 143        struct snd_soc_pcm_runtime *rtd = substream->private_data;
 144        unsigned long totbytes = params_buffer_bytes(params);
 145        struct s3c_dma_params *dma =
 146                snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 147        struct samsung_dma_req req;
 148        struct samsung_dma_config config;
 149
 150        pr_debug("Entered %s\n", __func__);
 151
 152        /* return if this is a bufferless transfer e.g.
 153         * codec <--> BT codec or GSM modem -- lg FIXME */
 154        if (!dma)
 155                return 0;
 156
 157        /* this may get called several times by oss emulation
 158         * with different params -HW */
 159        if (prtd->params == NULL) {
 160                /* prepare DMA */
 161                prtd->params = dma;
 162
 163                pr_debug("params %p, client %p, channel %d\n", prtd->params,
 164                        prtd->params->client, prtd->params->channel);
 165
 166                prtd->params->ops = samsung_dma_get_ops();
 167
 168                req.cap = (samsung_dma_has_circular() ?
 169                        DMA_CYCLIC : DMA_SLAVE);
 170                req.client = prtd->params->client;
 171                config.direction =
 172                        (substream->stream == SNDRV_PCM_STREAM_PLAYBACK
 173                        ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM);
 174                config.width = prtd->params->dma_size;
 175                config.fifo = prtd->params->dma_addr;
 176                prtd->params->ch = prtd->params->ops->request(
 177                                prtd->params->channel, &req, rtd->cpu_dai->dev,
 178                                prtd->params->ch_name);
 179                prtd->params->ops->config(prtd->params->ch, &config);
 180        }
 181
 182        snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
 183
 184        runtime->dma_bytes = totbytes;
 185
 186        spin_lock_irq(&prtd->lock);
 187        prtd->dma_loaded = 0;
 188        prtd->dma_period = params_period_bytes(params);
 189        prtd->dma_start = runtime->dma_addr;
 190        prtd->dma_pos = prtd->dma_start;
 191        prtd->dma_end = prtd->dma_start + totbytes;
 192        spin_unlock_irq(&prtd->lock);
 193
 194        return 0;
 195}
 196
 197static int dma_hw_free(struct snd_pcm_substream *substream)
 198{
 199        struct runtime_data *prtd = substream->runtime->private_data;
 200
 201        pr_debug("Entered %s\n", __func__);
 202
 203        snd_pcm_set_runtime_buffer(substream, NULL);
 204
 205        if (prtd->params) {
 206                prtd->params->ops->flush(prtd->params->ch);
 207                prtd->params->ops->release(prtd->params->ch,
 208                                        prtd->params->client);
 209                prtd->params = NULL;
 210        }
 211
 212        return 0;
 213}
 214
 215static int dma_prepare(struct snd_pcm_substream *substream)
 216{
 217        struct runtime_data *prtd = substream->runtime->private_data;
 218        int ret = 0;
 219
 220        pr_debug("Entered %s\n", __func__);
 221
 222        /* return if this is a bufferless transfer e.g.
 223         * codec <--> BT codec or GSM modem -- lg FIXME */
 224        if (!prtd->params)
 225                return 0;
 226
 227        /* flush the DMA channel */
 228        prtd->params->ops->flush(prtd->params->ch);
 229
 230        prtd->dma_loaded = 0;
 231        prtd->dma_pos = prtd->dma_start;
 232
 233        /* enqueue dma buffers */
 234        dma_enqueue(substream);
 235
 236        return ret;
 237}
 238
 239static int dma_trigger(struct snd_pcm_substream *substream, int cmd)
 240{
 241        struct runtime_data *prtd = substream->runtime->private_data;
 242        int ret = 0;
 243
 244        pr_debug("Entered %s\n", __func__);
 245
 246        spin_lock(&prtd->lock);
 247
 248        switch (cmd) {
 249        case SNDRV_PCM_TRIGGER_START:
 250                prtd->state |= ST_RUNNING;
 251                prtd->params->ops->trigger(prtd->params->ch);
 252                break;
 253
 254        case SNDRV_PCM_TRIGGER_STOP:
 255                prtd->state &= ~ST_RUNNING;
 256                prtd->params->ops->stop(prtd->params->ch);
 257                break;
 258
 259        default:
 260                ret = -EINVAL;
 261                break;
 262        }
 263
 264        spin_unlock(&prtd->lock);
 265
 266        return ret;
 267}
 268
 269static snd_pcm_uframes_t
 270dma_pointer(struct snd_pcm_substream *substream)
 271{
 272        struct snd_pcm_runtime *runtime = substream->runtime;
 273        struct runtime_data *prtd = runtime->private_data;
 274        unsigned long res;
 275
 276        pr_debug("Entered %s\n", __func__);
 277
 278        res = prtd->dma_pos - prtd->dma_start;
 279
 280        pr_debug("Pointer offset: %lu\n", res);
 281
 282        /* we seem to be getting the odd error from the pcm library due
 283         * to out-of-bounds pointers. this is maybe due to the dma engine
 284         * not having loaded the new values for the channel before being
 285         * called... (todo - fix )
 286         */
 287
 288        if (res >= snd_pcm_lib_buffer_bytes(substream)) {
 289                if (res == snd_pcm_lib_buffer_bytes(substream))
 290                        res = 0;
 291        }
 292
 293        return bytes_to_frames(substream->runtime, res);
 294}
 295
 296static int dma_open(struct snd_pcm_substream *substream)
 297{
 298        struct snd_pcm_runtime *runtime = substream->runtime;
 299        struct runtime_data *prtd;
 300
 301        pr_debug("Entered %s\n", __func__);
 302
 303        snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 304        snd_soc_set_runtime_hwparams(substream, &dma_hardware);
 305
 306        prtd = kzalloc(sizeof(struct runtime_data), GFP_KERNEL);
 307        if (prtd == NULL)
 308                return -ENOMEM;
 309
 310        spin_lock_init(&prtd->lock);
 311
 312        runtime->private_data = prtd;
 313        return 0;
 314}
 315
 316static int dma_close(struct snd_pcm_substream *substream)
 317{
 318        struct snd_pcm_runtime *runtime = substream->runtime;
 319        struct runtime_data *prtd = runtime->private_data;
 320
 321        pr_debug("Entered %s\n", __func__);
 322
 323        if (!prtd)
 324                pr_debug("dma_close called with prtd == NULL\n");
 325
 326        kfree(prtd);
 327
 328        return 0;
 329}
 330
 331static int dma_mmap(struct snd_pcm_substream *substream,
 332        struct vm_area_struct *vma)
 333{
 334        struct snd_pcm_runtime *runtime = substream->runtime;
 335
 336        pr_debug("Entered %s\n", __func__);
 337
 338        return dma_mmap_writecombine(substream->pcm->card->dev, vma,
 339                                     runtime->dma_area,
 340                                     runtime->dma_addr,
 341                                     runtime->dma_bytes);
 342}
 343
 344static struct snd_pcm_ops dma_ops = {
 345        .open           = dma_open,
 346        .close          = dma_close,
 347        .ioctl          = snd_pcm_lib_ioctl,
 348        .hw_params      = dma_hw_params,
 349        .hw_free        = dma_hw_free,
 350        .prepare        = dma_prepare,
 351        .trigger        = dma_trigger,
 352        .pointer        = dma_pointer,
 353        .mmap           = dma_mmap,
 354};
 355
 356static int preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
 357{
 358        struct snd_pcm_substream *substream = pcm->streams[stream].substream;
 359        struct snd_dma_buffer *buf = &substream->dma_buffer;
 360        size_t size = dma_hardware.buffer_bytes_max;
 361
 362        pr_debug("Entered %s\n", __func__);
 363
 364        buf->dev.type = SNDRV_DMA_TYPE_DEV;
 365        buf->dev.dev = pcm->card->dev;
 366        buf->private_data = NULL;
 367        buf->area = dma_alloc_writecombine(pcm->card->dev, size,
 368                                           &buf->addr, GFP_KERNEL);
 369        if (!buf->area)
 370                return -ENOMEM;
 371        buf->bytes = size;
 372        return 0;
 373}
 374
 375static void dma_free_dma_buffers(struct snd_pcm *pcm)
 376{
 377        struct snd_pcm_substream *substream;
 378        struct snd_dma_buffer *buf;
 379        int stream;
 380
 381        pr_debug("Entered %s\n", __func__);
 382
 383        for (stream = 0; stream < 2; stream++) {
 384                substream = pcm->streams[stream].substream;
 385                if (!substream)
 386                        continue;
 387
 388                buf = &substream->dma_buffer;
 389                if (!buf->area)
 390                        continue;
 391
 392                dma_free_writecombine(pcm->card->dev, buf->bytes,
 393                                      buf->area, buf->addr);
 394                buf->area = NULL;
 395        }
 396}
 397
 398static u64 dma_mask = DMA_BIT_MASK(32);
 399
 400static int dma_new(struct snd_soc_pcm_runtime *rtd)
 401{
 402        struct snd_card *card = rtd->card->snd_card;
 403        struct snd_pcm *pcm = rtd->pcm;
 404        int ret = 0;
 405
 406        pr_debug("Entered %s\n", __func__);
 407
 408        if (!card->dev->dma_mask)
 409                card->dev->dma_mask = &dma_mask;
 410        if (!card->dev->coherent_dma_mask)
 411                card->dev->coherent_dma_mask = DMA_BIT_MASK(32);
 412
 413        if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
 414                ret = preallocate_dma_buffer(pcm,
 415                        SNDRV_PCM_STREAM_PLAYBACK);
 416                if (ret)
 417                        goto out;
 418        }
 419
 420        if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
 421                ret = preallocate_dma_buffer(pcm,
 422                        SNDRV_PCM_STREAM_CAPTURE);
 423                if (ret)
 424                        goto out;
 425        }
 426out:
 427        return ret;
 428}
 429
 430static struct snd_soc_platform_driver samsung_asoc_platform = {
 431        .ops            = &dma_ops,
 432        .pcm_new        = dma_new,
 433        .pcm_free       = dma_free_dma_buffers,
 434};
 435
 436int asoc_dma_platform_register(struct device *dev)
 437{
 438        return snd_soc_register_platform(dev, &samsung_asoc_platform);
 439}
 440EXPORT_SYMBOL_GPL(asoc_dma_platform_register);
 441
 442void asoc_dma_platform_unregister(struct device *dev)
 443{
 444        snd_soc_unregister_platform(dev);
 445}
 446EXPORT_SYMBOL_GPL(asoc_dma_platform_unregister);
 447
 448MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
 449MODULE_DESCRIPTION("Samsung ASoC DMA Driver");
 450MODULE_LICENSE("GPL");
 451