linux/sound/sh/sh_dac_audio.c
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   1/*
   2 * sh_dac_audio.c - SuperH DAC audio driver for ALSA
   3 *
   4 * Copyright (c) 2009 by Rafael Ignacio Zurita <rizurita@yahoo.com>
   5 *
   6 *
   7 * Based on sh_dac_audio.c (Copyright (C) 2004, 2005 by Andriy Skulysh)
   8 *
   9 *   This program is free software; you can redistribute it and/or modify
  10 *   it under the terms of the GNU General Public License as published by
  11 *   the Free Software Foundation; either version 2 of the License, or
  12 *   (at your option) any later version.
  13 *
  14 *   This program is distributed in the hope that it will be useful,
  15 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 *   GNU General Public License for more details.
  18 *
  19 *   You should have received a copy of the GNU General Public License
  20 *   along with this program; if not, write to the Free Software
  21 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  22 *
  23 */
  24
  25#include <linux/hrtimer.h>
  26#include <linux/interrupt.h>
  27#include <linux/io.h>
  28#include <linux/platform_device.h>
  29#include <linux/slab.h>
  30#include <linux/module.h>
  31#include <sound/core.h>
  32#include <sound/initval.h>
  33#include <sound/pcm.h>
  34#include <sound/sh_dac_audio.h>
  35#include <asm/clock.h>
  36#include <asm/hd64461.h>
  37#include <mach/hp6xx.h>
  38#include <cpu/dac.h>
  39
  40MODULE_AUTHOR("Rafael Ignacio Zurita <rizurita@yahoo.com>");
  41MODULE_DESCRIPTION("SuperH DAC audio driver");
  42MODULE_LICENSE("GPL");
  43MODULE_SUPPORTED_DEVICE("{{SuperH DAC audio support}}");
  44
  45/* Module Parameters */
  46static int index = SNDRV_DEFAULT_IDX1;
  47static char *id = SNDRV_DEFAULT_STR1;
  48module_param(index, int, 0444);
  49MODULE_PARM_DESC(index, "Index value for SuperH DAC audio.");
  50module_param(id, charp, 0444);
  51MODULE_PARM_DESC(id, "ID string for SuperH DAC audio.");
  52
  53/* main struct */
  54struct snd_sh_dac {
  55        struct snd_card *card;
  56        struct snd_pcm_substream *substream;
  57        struct hrtimer hrtimer;
  58        ktime_t wakeups_per_second;
  59
  60        int rate;
  61        int empty;
  62        char *data_buffer, *buffer_begin, *buffer_end;
  63        int processed; /* bytes proccesed, to compare with period_size */
  64        int buffer_size;
  65        struct dac_audio_pdata *pdata;
  66};
  67
  68
  69static void dac_audio_start_timer(struct snd_sh_dac *chip)
  70{
  71        hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
  72                      HRTIMER_MODE_REL);
  73}
  74
  75static void dac_audio_stop_timer(struct snd_sh_dac *chip)
  76{
  77        hrtimer_cancel(&chip->hrtimer);
  78}
  79
  80static void dac_audio_reset(struct snd_sh_dac *chip)
  81{
  82        dac_audio_stop_timer(chip);
  83        chip->buffer_begin = chip->buffer_end = chip->data_buffer;
  84        chip->processed = 0;
  85        chip->empty = 1;
  86}
  87
  88static void dac_audio_set_rate(struct snd_sh_dac *chip)
  89{
  90        chip->wakeups_per_second = ktime_set(0, 1000000000 / chip->rate);
  91}
  92
  93
  94/* PCM INTERFACE */
  95
  96static struct snd_pcm_hardware snd_sh_dac_pcm_hw = {
  97        .info                   = (SNDRV_PCM_INFO_MMAP |
  98                                        SNDRV_PCM_INFO_MMAP_VALID |
  99                                        SNDRV_PCM_INFO_INTERLEAVED |
 100                                        SNDRV_PCM_INFO_HALF_DUPLEX),
 101        .formats                = SNDRV_PCM_FMTBIT_U8,
 102        .rates                  = SNDRV_PCM_RATE_8000,
 103        .rate_min               = 8000,
 104        .rate_max               = 8000,
 105        .channels_min           = 1,
 106        .channels_max           = 1,
 107        .buffer_bytes_max       = (48*1024),
 108        .period_bytes_min       = 1,
 109        .period_bytes_max       = (48*1024),
 110        .periods_min            = 1,
 111        .periods_max            = 1024,
 112};
 113
 114static int snd_sh_dac_pcm_open(struct snd_pcm_substream *substream)
 115{
 116        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 117        struct snd_pcm_runtime *runtime = substream->runtime;
 118
 119        runtime->hw = snd_sh_dac_pcm_hw;
 120
 121        chip->substream = substream;
 122        chip->buffer_begin = chip->buffer_end = chip->data_buffer;
 123        chip->processed = 0;
 124        chip->empty = 1;
 125
 126        chip->pdata->start(chip->pdata);
 127
 128        return 0;
 129}
 130
 131static int snd_sh_dac_pcm_close(struct snd_pcm_substream *substream)
 132{
 133        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 134
 135        chip->substream = NULL;
 136
 137        dac_audio_stop_timer(chip);
 138        chip->pdata->stop(chip->pdata);
 139
 140        return 0;
 141}
 142
 143static int snd_sh_dac_pcm_hw_params(struct snd_pcm_substream *substream,
 144                                struct snd_pcm_hw_params *hw_params)
 145{
 146        return snd_pcm_lib_malloc_pages(substream,
 147                        params_buffer_bytes(hw_params));
 148}
 149
 150static int snd_sh_dac_pcm_hw_free(struct snd_pcm_substream *substream)
 151{
 152        return snd_pcm_lib_free_pages(substream);
 153}
 154
 155static int snd_sh_dac_pcm_prepare(struct snd_pcm_substream *substream)
 156{
 157        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 158        struct snd_pcm_runtime *runtime = chip->substream->runtime;
 159
 160        chip->buffer_size = runtime->buffer_size;
 161        memset(chip->data_buffer, 0, chip->pdata->buffer_size);
 162
 163        return 0;
 164}
 165
 166static int snd_sh_dac_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 167{
 168        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 169
 170        switch (cmd) {
 171        case SNDRV_PCM_TRIGGER_START:
 172                dac_audio_start_timer(chip);
 173                break;
 174        case SNDRV_PCM_TRIGGER_STOP:
 175                chip->buffer_begin = chip->buffer_end = chip->data_buffer;
 176                chip->processed = 0;
 177                chip->empty = 1;
 178                dac_audio_stop_timer(chip);
 179                break;
 180        default:
 181                 return -EINVAL;
 182        }
 183
 184        return 0;
 185}
 186
 187static int snd_sh_dac_pcm_copy(struct snd_pcm_substream *substream, int channel,
 188        snd_pcm_uframes_t pos, void __user *src, snd_pcm_uframes_t count)
 189{
 190        /* channel is not used (interleaved data) */
 191        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 192        struct snd_pcm_runtime *runtime = substream->runtime;
 193        ssize_t b_count = frames_to_bytes(runtime , count);
 194        ssize_t b_pos = frames_to_bytes(runtime , pos);
 195
 196        if (count < 0)
 197                return -EINVAL;
 198
 199        if (!count)
 200                return 0;
 201
 202        memcpy_toio(chip->data_buffer + b_pos, src, b_count);
 203        chip->buffer_end = chip->data_buffer + b_pos + b_count;
 204
 205        if (chip->empty) {
 206                chip->empty = 0;
 207                dac_audio_start_timer(chip);
 208        }
 209
 210        return 0;
 211}
 212
 213static int snd_sh_dac_pcm_silence(struct snd_pcm_substream *substream,
 214                                  int channel, snd_pcm_uframes_t pos,
 215                                  snd_pcm_uframes_t count)
 216{
 217        /* channel is not used (interleaved data) */
 218        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 219        struct snd_pcm_runtime *runtime = substream->runtime;
 220        ssize_t b_count = frames_to_bytes(runtime , count);
 221        ssize_t b_pos = frames_to_bytes(runtime , pos);
 222
 223        if (count < 0)
 224                return -EINVAL;
 225
 226        if (!count)
 227                return 0;
 228
 229        memset_io(chip->data_buffer + b_pos, 0, b_count);
 230        chip->buffer_end = chip->data_buffer + b_pos + b_count;
 231
 232        if (chip->empty) {
 233                chip->empty = 0;
 234                dac_audio_start_timer(chip);
 235        }
 236
 237        return 0;
 238}
 239
 240static
 241snd_pcm_uframes_t snd_sh_dac_pcm_pointer(struct snd_pcm_substream *substream)
 242{
 243        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 244        int pointer = chip->buffer_begin - chip->data_buffer;
 245
 246        return pointer;
 247}
 248
 249/* pcm ops */
 250static struct snd_pcm_ops snd_sh_dac_pcm_ops = {
 251        .open           = snd_sh_dac_pcm_open,
 252        .close          = snd_sh_dac_pcm_close,
 253        .ioctl          = snd_pcm_lib_ioctl,
 254        .hw_params      = snd_sh_dac_pcm_hw_params,
 255        .hw_free        = snd_sh_dac_pcm_hw_free,
 256        .prepare        = snd_sh_dac_pcm_prepare,
 257        .trigger        = snd_sh_dac_pcm_trigger,
 258        .pointer        = snd_sh_dac_pcm_pointer,
 259        .copy           = snd_sh_dac_pcm_copy,
 260        .silence        = snd_sh_dac_pcm_silence,
 261        .mmap           = snd_pcm_lib_mmap_iomem,
 262};
 263
 264static int snd_sh_dac_pcm(struct snd_sh_dac *chip, int device)
 265{
 266        int err;
 267        struct snd_pcm *pcm;
 268
 269        /* device should be always 0 for us */
 270        err = snd_pcm_new(chip->card, "SH_DAC PCM", device, 1, 0, &pcm);
 271        if (err < 0)
 272                return err;
 273
 274        pcm->private_data = chip;
 275        strcpy(pcm->name, "SH_DAC PCM");
 276        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sh_dac_pcm_ops);
 277
 278        /* buffer size=48K */
 279        snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
 280                                          snd_dma_continuous_data(GFP_KERNEL),
 281                                                        48 * 1024,
 282                                                        48 * 1024);
 283
 284        return 0;
 285}
 286/* END OF PCM INTERFACE */
 287
 288
 289/* driver .remove  --  destructor */
 290static int snd_sh_dac_remove(struct platform_device *devptr)
 291{
 292        snd_card_free(platform_get_drvdata(devptr));
 293        return 0;
 294}
 295
 296/* free -- it has been defined by create */
 297static int snd_sh_dac_free(struct snd_sh_dac *chip)
 298{
 299        /* release the data */
 300        kfree(chip->data_buffer);
 301        kfree(chip);
 302
 303        return 0;
 304}
 305
 306static int snd_sh_dac_dev_free(struct snd_device *device)
 307{
 308        struct snd_sh_dac *chip = device->device_data;
 309
 310        return snd_sh_dac_free(chip);
 311}
 312
 313static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
 314{
 315        struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac,
 316                                               hrtimer);
 317        struct snd_pcm_runtime *runtime = chip->substream->runtime;
 318        ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size);
 319
 320        if (!chip->empty) {
 321                sh_dac_output(*chip->buffer_begin, chip->pdata->channel);
 322                chip->buffer_begin++;
 323
 324                chip->processed++;
 325                if (chip->processed >= b_ps) {
 326                        chip->processed -= b_ps;
 327                        snd_pcm_period_elapsed(chip->substream);
 328                }
 329
 330                if (chip->buffer_begin == (chip->data_buffer +
 331                                           chip->buffer_size - 1))
 332                        chip->buffer_begin = chip->data_buffer;
 333
 334                if (chip->buffer_begin == chip->buffer_end)
 335                        chip->empty = 1;
 336
 337        }
 338
 339        if (!chip->empty)
 340                hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
 341                              HRTIMER_MODE_REL);
 342
 343        return HRTIMER_NORESTART;
 344}
 345
 346/* create  --  chip-specific constructor for the cards components */
 347static int snd_sh_dac_create(struct snd_card *card,
 348                             struct platform_device *devptr,
 349                             struct snd_sh_dac **rchip)
 350{
 351        struct snd_sh_dac *chip;
 352        int err;
 353
 354        static struct snd_device_ops ops = {
 355                   .dev_free = snd_sh_dac_dev_free,
 356        };
 357
 358        *rchip = NULL;
 359
 360        chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 361        if (chip == NULL)
 362                return -ENOMEM;
 363
 364        chip->card = card;
 365
 366        hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 367        chip->hrtimer.function = sh_dac_audio_timer;
 368
 369        dac_audio_reset(chip);
 370        chip->rate = 8000;
 371        dac_audio_set_rate(chip);
 372
 373        chip->pdata = devptr->dev.platform_data;
 374
 375        chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL);
 376        if (chip->data_buffer == NULL) {
 377                kfree(chip);
 378                return -ENOMEM;
 379        }
 380
 381        err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
 382        if (err < 0) {
 383                snd_sh_dac_free(chip);
 384                return err;
 385        }
 386
 387        *rchip = chip;
 388
 389        return 0;
 390}
 391
 392/* driver .probe  --  constructor */
 393static int snd_sh_dac_probe(struct platform_device *devptr)
 394{
 395        struct snd_sh_dac *chip;
 396        struct snd_card *card;
 397        int err;
 398
 399        err = snd_card_create(index, id, THIS_MODULE, 0, &card);
 400        if (err < 0) {
 401                        snd_printk(KERN_ERR "cannot allocate the card\n");
 402                        return err;
 403        }
 404
 405        err = snd_sh_dac_create(card, devptr, &chip);
 406        if (err < 0)
 407                goto probe_error;
 408
 409        err = snd_sh_dac_pcm(chip, 0);
 410        if (err < 0)
 411                goto probe_error;
 412
 413        strcpy(card->driver, "snd_sh_dac");
 414        strcpy(card->shortname, "SuperH DAC audio driver");
 415        printk(KERN_INFO "%s %s", card->longname, card->shortname);
 416
 417        err = snd_card_register(card);
 418        if (err < 0)
 419                goto probe_error;
 420
 421        snd_printk("ALSA driver for SuperH DAC audio");
 422
 423        platform_set_drvdata(devptr, card);
 424        return 0;
 425
 426probe_error:
 427        snd_card_free(card);
 428        return err;
 429}
 430
 431/*
 432 * "driver" definition
 433 */
 434static struct platform_driver sh_dac_driver = {
 435        .probe  = snd_sh_dac_probe,
 436        .remove = snd_sh_dac_remove,
 437        .driver = {
 438                .name = "dac_audio",
 439                .owner  = THIS_MODULE,
 440        },
 441};
 442
 443module_platform_driver(sh_dac_driver);
 444
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