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 <sound/core.h>
  31#include <sound/initval.h>
  32#include <sound/pcm.h>
  33#include <sound/sh_dac_audio.h>
  34#include <asm/clock.h>
  35#include <asm/hd64461.h>
  36#include <mach/hp6xx.h>
  37#include <cpu/dac.h>
  38
  39MODULE_AUTHOR("Rafael Ignacio Zurita <rizurita@yahoo.com>");
  40MODULE_DESCRIPTION("SuperH DAC audio driver");
  41MODULE_LICENSE("GPL");
  42MODULE_SUPPORTED_DEVICE("{{SuperH DAC audio support}}");
  43
  44/* Module Parameters */
  45static int index = SNDRV_DEFAULT_IDX1;
  46static char *id = SNDRV_DEFAULT_STR1;
  47module_param(index, int, 0444);
  48MODULE_PARM_DESC(index, "Index value for SuperH DAC audio.");
  49module_param(id, charp, 0444);
  50MODULE_PARM_DESC(id, "ID string for SuperH DAC audio.");
  51
  52/* main struct */
  53struct snd_sh_dac {
  54        struct snd_card *card;
  55        struct snd_pcm_substream *substream;
  56        struct hrtimer hrtimer;
  57        ktime_t wakeups_per_second;
  58
  59        int rate;
  60        int empty;
  61        char *data_buffer, *buffer_begin, *buffer_end;
  62        int processed; /* bytes proccesed, to compare with period_size */
  63        int buffer_size;
  64        struct dac_audio_pdata *pdata;
  65};
  66
  67
  68static void dac_audio_start_timer(struct snd_sh_dac *chip)
  69{
  70        hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
  71                      HRTIMER_MODE_REL);
  72}
  73
  74static void dac_audio_stop_timer(struct snd_sh_dac *chip)
  75{
  76        hrtimer_cancel(&chip->hrtimer);
  77}
  78
  79static void dac_audio_reset(struct snd_sh_dac *chip)
  80{
  81        dac_audio_stop_timer(chip);
  82        chip->buffer_begin = chip->buffer_end = chip->data_buffer;
  83        chip->processed = 0;
  84        chip->empty = 1;
  85}
  86
  87static void dac_audio_set_rate(struct snd_sh_dac *chip)
  88{
  89        chip->wakeups_per_second = ktime_set(0, 1000000000 / chip->rate);
  90}
  91
  92
  93/* PCM INTERFACE */
  94
  95static struct snd_pcm_hardware snd_sh_dac_pcm_hw = {
  96        .info                   = (SNDRV_PCM_INFO_MMAP |
  97                                        SNDRV_PCM_INFO_MMAP_VALID |
  98                                        SNDRV_PCM_INFO_INTERLEAVED |
  99                                        SNDRV_PCM_INFO_HALF_DUPLEX),
 100        .formats                = SNDRV_PCM_FMTBIT_U8,
 101        .rates                  = SNDRV_PCM_RATE_8000,
 102        .rate_min               = 8000,
 103        .rate_max               = 8000,
 104        .channels_min           = 1,
 105        .channels_max           = 1,
 106        .buffer_bytes_max       = (48*1024),
 107        .period_bytes_min       = 1,
 108        .period_bytes_max       = (48*1024),
 109        .periods_min            = 1,
 110        .periods_max            = 1024,
 111};
 112
 113static int snd_sh_dac_pcm_open(struct snd_pcm_substream *substream)
 114{
 115        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 116        struct snd_pcm_runtime *runtime = substream->runtime;
 117
 118        runtime->hw = snd_sh_dac_pcm_hw;
 119
 120        chip->substream = substream;
 121        chip->buffer_begin = chip->buffer_end = chip->data_buffer;
 122        chip->processed = 0;
 123        chip->empty = 1;
 124
 125        chip->pdata->start(chip->pdata);
 126
 127        return 0;
 128}
 129
 130static int snd_sh_dac_pcm_close(struct snd_pcm_substream *substream)
 131{
 132        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 133
 134        chip->substream = NULL;
 135
 136        dac_audio_stop_timer(chip);
 137        chip->pdata->stop(chip->pdata);
 138
 139        return 0;
 140}
 141
 142static int snd_sh_dac_pcm_hw_params(struct snd_pcm_substream *substream,
 143                                struct snd_pcm_hw_params *hw_params)
 144{
 145        return snd_pcm_lib_malloc_pages(substream,
 146                        params_buffer_bytes(hw_params));
 147}
 148
 149static int snd_sh_dac_pcm_hw_free(struct snd_pcm_substream *substream)
 150{
 151        return snd_pcm_lib_free_pages(substream);
 152}
 153
 154static int snd_sh_dac_pcm_prepare(struct snd_pcm_substream *substream)
 155{
 156        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 157        struct snd_pcm_runtime *runtime = chip->substream->runtime;
 158
 159        chip->buffer_size = runtime->buffer_size;
 160        memset(chip->data_buffer, 0, chip->pdata->buffer_size);
 161
 162        return 0;
 163}
 164
 165static int snd_sh_dac_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 166{
 167        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 168
 169        switch (cmd) {
 170        case SNDRV_PCM_TRIGGER_START:
 171                dac_audio_start_timer(chip);
 172                break;
 173        case SNDRV_PCM_TRIGGER_STOP:
 174                chip->buffer_begin = chip->buffer_end = chip->data_buffer;
 175                chip->processed = 0;
 176                chip->empty = 1;
 177                dac_audio_stop_timer(chip);
 178                break;
 179        default:
 180                 return -EINVAL;
 181        }
 182
 183        return 0;
 184}
 185
 186static int snd_sh_dac_pcm_copy(struct snd_pcm_substream *substream, int channel,
 187        snd_pcm_uframes_t pos, void __user *src, snd_pcm_uframes_t count)
 188{
 189        /* channel is not used (interleaved data) */
 190        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 191        struct snd_pcm_runtime *runtime = substream->runtime;
 192        ssize_t b_count = frames_to_bytes(runtime , count);
 193        ssize_t b_pos = frames_to_bytes(runtime , pos);
 194
 195        if (count < 0)
 196                return -EINVAL;
 197
 198        if (!count)
 199                return 0;
 200
 201        memcpy_toio(chip->data_buffer + b_pos, src, b_count);
 202        chip->buffer_end = chip->data_buffer + b_pos + b_count;
 203
 204        if (chip->empty) {
 205                chip->empty = 0;
 206                dac_audio_start_timer(chip);
 207        }
 208
 209        return 0;
 210}
 211
 212static int snd_sh_dac_pcm_silence(struct snd_pcm_substream *substream,
 213                                  int channel, snd_pcm_uframes_t pos,
 214                                  snd_pcm_uframes_t count)
 215{
 216        /* channel is not used (interleaved data) */
 217        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 218        struct snd_pcm_runtime *runtime = substream->runtime;
 219        ssize_t b_count = frames_to_bytes(runtime , count);
 220        ssize_t b_pos = frames_to_bytes(runtime , pos);
 221
 222        if (count < 0)
 223                return -EINVAL;
 224
 225        if (!count)
 226                return 0;
 227
 228        memset_io(chip->data_buffer + b_pos, 0, b_count);
 229        chip->buffer_end = chip->data_buffer + b_pos + b_count;
 230
 231        if (chip->empty) {
 232                chip->empty = 0;
 233                dac_audio_start_timer(chip);
 234        }
 235
 236        return 0;
 237}
 238
 239static
 240snd_pcm_uframes_t snd_sh_dac_pcm_pointer(struct snd_pcm_substream *substream)
 241{
 242        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 243        int pointer = chip->buffer_begin - chip->data_buffer;
 244
 245        return pointer;
 246}
 247
 248/* pcm ops */
 249static struct snd_pcm_ops snd_sh_dac_pcm_ops = {
 250        .open           = snd_sh_dac_pcm_open,
 251        .close          = snd_sh_dac_pcm_close,
 252        .ioctl          = snd_pcm_lib_ioctl,
 253        .hw_params      = snd_sh_dac_pcm_hw_params,
 254        .hw_free        = snd_sh_dac_pcm_hw_free,
 255        .prepare        = snd_sh_dac_pcm_prepare,
 256        .trigger        = snd_sh_dac_pcm_trigger,
 257        .pointer        = snd_sh_dac_pcm_pointer,
 258        .copy           = snd_sh_dac_pcm_copy,
 259        .silence        = snd_sh_dac_pcm_silence,
 260        .mmap           = snd_pcm_lib_mmap_iomem,
 261};
 262
 263static int __devinit snd_sh_dac_pcm(struct snd_sh_dac *chip, int device)
 264{
 265        int err;
 266        struct snd_pcm *pcm;
 267
 268        /* device should be always 0 for us */
 269        err = snd_pcm_new(chip->card, "SH_DAC PCM", device, 1, 0, &pcm);
 270        if (err < 0)
 271                return err;
 272
 273        pcm->private_data = chip;
 274        strcpy(pcm->name, "SH_DAC PCM");
 275        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sh_dac_pcm_ops);
 276
 277        /* buffer size=48K */
 278        snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
 279                                          snd_dma_continuous_data(GFP_KERNEL),
 280                                                        48 * 1024,
 281                                                        48 * 1024);
 282
 283        return 0;
 284}
 285/* END OF PCM INTERFACE */
 286
 287
 288/* driver .remove  --  destructor */
 289static int snd_sh_dac_remove(struct platform_device *devptr)
 290{
 291        snd_card_free(platform_get_drvdata(devptr));
 292        platform_set_drvdata(devptr, NULL);
 293
 294        return 0;
 295}
 296
 297/* free -- it has been defined by create */
 298static int snd_sh_dac_free(struct snd_sh_dac *chip)
 299{
 300        /* release the data */
 301        kfree(chip->data_buffer);
 302        kfree(chip);
 303
 304        return 0;
 305}
 306
 307static int snd_sh_dac_dev_free(struct snd_device *device)
 308{
 309        struct snd_sh_dac *chip = device->device_data;
 310
 311        return snd_sh_dac_free(chip);
 312}
 313
 314static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
 315{
 316        struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac,
 317                                               hrtimer);
 318        struct snd_pcm_runtime *runtime = chip->substream->runtime;
 319        ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size);
 320
 321        if (!chip->empty) {
 322                sh_dac_output(*chip->buffer_begin, chip->pdata->channel);
 323                chip->buffer_begin++;
 324
 325                chip->processed++;
 326                if (chip->processed >= b_ps) {
 327                        chip->processed -= b_ps;
 328                        snd_pcm_period_elapsed(chip->substream);
 329                }
 330
 331                if (chip->buffer_begin == (chip->data_buffer +
 332                                           chip->buffer_size - 1))
 333                        chip->buffer_begin = chip->data_buffer;
 334
 335                if (chip->buffer_begin == chip->buffer_end)
 336                        chip->empty = 1;
 337
 338        }
 339
 340        if (!chip->empty)
 341                hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
 342                              HRTIMER_MODE_REL);
 343
 344        return HRTIMER_NORESTART;
 345}
 346
 347/* create  --  chip-specific constructor for the cards components */
 348static int __devinit snd_sh_dac_create(struct snd_card *card,
 349                                       struct platform_device *devptr,
 350                                       struct snd_sh_dac **rchip)
 351{
 352        struct snd_sh_dac *chip;
 353        int err;
 354
 355        static struct snd_device_ops ops = {
 356                   .dev_free = snd_sh_dac_dev_free,
 357        };
 358
 359        *rchip = NULL;
 360
 361        chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 362        if (chip == NULL)
 363                return -ENOMEM;
 364
 365        chip->card = card;
 366
 367        hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 368        chip->hrtimer.function = sh_dac_audio_timer;
 369
 370        dac_audio_reset(chip);
 371        chip->rate = 8000;
 372        dac_audio_set_rate(chip);
 373
 374        chip->pdata = devptr->dev.platform_data;
 375
 376        chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL);
 377        if (chip->data_buffer == NULL) {
 378                kfree(chip);
 379                return -ENOMEM;
 380        }
 381
 382        err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
 383        if (err < 0) {
 384                snd_sh_dac_free(chip);
 385                return err;
 386        }
 387
 388        *rchip = chip;
 389
 390        return 0;
 391}
 392
 393/* driver .probe  --  constructor */
 394static int __devinit snd_sh_dac_probe(struct platform_device *devptr)
 395{
 396        struct snd_sh_dac *chip;
 397        struct snd_card *card;
 398        int err;
 399
 400        err = snd_card_create(index, id, THIS_MODULE, 0, &card);
 401        if (err < 0) {
 402                        snd_printk(KERN_ERR "cannot allocate the card\n");
 403                        return err;
 404        }
 405
 406        err = snd_sh_dac_create(card, devptr, &chip);
 407        if (err < 0)
 408                goto probe_error;
 409
 410        err = snd_sh_dac_pcm(chip, 0);
 411        if (err < 0)
 412                goto probe_error;
 413
 414        strcpy(card->driver, "snd_sh_dac");
 415        strcpy(card->shortname, "SuperH DAC audio driver");
 416        printk(KERN_INFO "%s %s", card->longname, card->shortname);
 417
 418        err = snd_card_register(card);
 419        if (err < 0)
 420                goto probe_error;
 421
 422        snd_printk("ALSA driver for SuperH DAC audio");
 423
 424        platform_set_drvdata(devptr, card);
 425        return 0;
 426
 427probe_error:
 428        snd_card_free(card);
 429        return err;
 430}
 431
 432/*
 433 * "driver" definition
 434 */
 435static struct platform_driver driver = {
 436        .probe  = snd_sh_dac_probe,
 437        .remove = snd_sh_dac_remove,
 438        .driver = {
 439                .name = "dac_audio",
 440        },
 441};
 442
 443static int __init sh_dac_init(void)
 444{
 445        return platform_driver_register(&driver);
 446}
 447
 448static void __exit sh_dac_exit(void)
 449{
 450        platform_driver_unregister(&driver);
 451}
 452
 453module_init(sh_dac_init);
 454module_exit(sh_dac_exit);
 455