sound/sh/sh_dac_audio.c

   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
  40 MODULE_AUTHOR("Rafael Ignacio Zurita <rizurita@yahoo.com>");
  41 MODULE_DESCRIPTION("SuperH DAC audio driver");
  42 MODULE_LICENSE("GPL");
  43 MODULE_SUPPORTED_DEVICE("{{SuperH DAC audio support}}");
  44
  45 /* Module Parameters */
  46 static int index = SNDRV_DEFAULT_IDX1;
  47 static char *id = SNDRV_DEFAULT_STR1;
  48 module_param(index, int, 0444);
  49 MODULE_PARM_DESC(index, "Index value for SuperH DAC audio.");
  50 module_param(id, charp, 0444);
  51 MODULE_PARM_DESC(id, "ID string for SuperH DAC audio.");
  52
  53 /* main struct */
  54 struct 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
  69 static 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
  75 static void dac_audio_stop_timer(struct snd_sh_dac *chip)
  76 {
  77         hrtimer_cancel(&chip->hrtimer);
  78 }
  79
  80 static 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
  88 static 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
  96 static 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
 114 static 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
 131 static 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
 143 static 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
 150 static int snd_sh_dac_pcm_hw_free(struct snd_pcm_substream *substream)
 151 {
 152         return snd_pcm_lib_free_pages(substream);
 153 }
 154
 155 static 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
 166 static 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
 187 static 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
 213 static 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
 240 static
 241 snd_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 */
 250 static 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
 264 static 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 */
 290 static int snd_sh_dac_remove(struct platform_device *devptr)
 291 {
 292         snd_card_free(platform_get_drvdata(devptr));
 293         platform_set_drvdata(devptr, NULL);
 294
 295         return 0;
 296 }
 297
 298 /* free -- it has been defined by create */
 299 static int snd_sh_dac_free(struct snd_sh_dac *chip)
 300 {
 301         /* release the data */
 302         kfree(chip->data_buffer);
 303         kfree(chip);
 304
 305         return 0;
 306 }
 307
 308 static int snd_sh_dac_dev_free(struct snd_device *device)
 309 {
 310         struct snd_sh_dac *chip = device->device_data;
 311
 312         return snd_sh_dac_free(chip);
 313 }
 314
 315 static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
 316 {
 317         struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac,
 318                                                hrtimer);
 319         struct snd_pcm_runtime *runtime = chip->substream->runtime;
 320         ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size);
 321
 322         if (!chip->empty) {
 323                 sh_dac_output(*chip->buffer_begin, chip->pdata->channel);
 324                 chip->buffer_begin++;
 325
 326                 chip->processed++;
 327                 if (chip->processed >= b_ps) {
 328                         chip->processed -= b_ps;
 329                         snd_pcm_period_elapsed(chip->substream);
 330                 }
 331
 332                 if (chip->buffer_begin == (chip->data_buffer +
 333                                            chip->buffer_size - 1))
 334                         chip->buffer_begin = chip->data_buffer;
 335
 336                 if (chip->buffer_begin == chip->buffer_end)
 337                         chip->empty = 1;
 338
 339         }
 340
 341         if (!chip->empty)
 342                 hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
 343                               HRTIMER_MODE_REL);
 344
 345         return HRTIMER_NORESTART;
 346 }
 347
 348 /* create  --  chip-specific constructor for the cards components */
 349 static int snd_sh_dac_create(struct snd_card *card,
 350                              struct platform_device *devptr,
 351                              struct snd_sh_dac **rchip)
 352 {
 353         struct snd_sh_dac *chip;
 354         int err;
 355
 356         static struct snd_device_ops ops = {
 357                    .dev_free = snd_sh_dac_dev_free,
 358         };
 359
 360         *rchip = NULL;
 361
 362         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 363         if (chip == NULL)
 364                 return -ENOMEM;
 365
 366         chip->card = card;
 367
 368         hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 369         chip->hrtimer.function = sh_dac_audio_timer;
 370
 371         dac_audio_reset(chip);
 372         chip->rate = 8000;
 373         dac_audio_set_rate(chip);
 374
 375         chip->pdata = devptr->dev.platform_data;
 376
 377         chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL);
 378         if (chip->data_buffer == NULL) {
 379                 kfree(chip);
 380                 return -ENOMEM;
 381         }
 382
 383         err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
 384         if (err < 0) {
 385                 snd_sh_dac_free(chip);
 386                 return err;
 387         }
 388
 389         *rchip = chip;
 390
 391         return 0;
 392 }
 393
 394 /* driver .probe  --  constructor */
 395 static int snd_sh_dac_probe(struct platform_device *devptr)
 396 {
 397         struct snd_sh_dac *chip;
 398         struct snd_card *card;
 399         int err;
 400
 401         err = snd_card_create(index, id, THIS_MODULE, 0, &card);
 402         if (err < 0) {
 403                         snd_printk(KERN_ERR "cannot allocate the card\n");
 404                         return err;
 405         }
 406
 407         err = snd_sh_dac_create(card, devptr, &chip);
 408         if (err < 0)
 409                 goto probe_error;
 410
 411         err = snd_sh_dac_pcm(chip, 0);
 412         if (err < 0)
 413                 goto probe_error;
 414
 415         strcpy(card->driver, "snd_sh_dac");
 416         strcpy(card->shortname, "SuperH DAC audio driver");
 417         printk(KERN_INFO "%s %s", card->longname, card->shortname);
 418
 419         err = snd_card_register(card);
 420         if (err < 0)
 421                 goto probe_error;
 422
 423         snd_printk("ALSA driver for SuperH DAC audio");
 424
 425         platform_set_drvdata(devptr, card);
 426         return 0;
 427
 428 probe_error:
 429         snd_card_free(card);
 430         return err;
 431 }
 432
 433 /*
 434  * "driver" definition
 435  */
 436 static struct platform_driver sh_dac_driver = {
 437         .probe  = snd_sh_dac_probe,
 438         .remove = snd_sh_dac_remove,
 439         .driver = {
 440                 .name = "dac_audio",
 441                 .owner  = THIS_MODULE,
 442         },
 443 };
 444
 445 module_platform_driver(sh_dac_driver);