sound/sh/sh_dac_audio.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * sh_dac_audio.c - SuperH DAC audio driver for ALSA
   4  *
   5  * Copyright (c) 2009 by Rafael Ignacio Zurita <rizurita@yahoo.com>
   6  *
   7  * Based on sh_dac_audio.c (Copyright (C) 2004, 2005 by Andriy Skulysh)
   8  */
   9
  10 #include <linux/hrtimer.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/io.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/slab.h>
  15 #include <linux/module.h>
  16 #include <sound/core.h>
  17 #include <sound/initval.h>
  18 #include <sound/pcm.h>
  19 #include <sound/sh_dac_audio.h>
  20 #include <asm/clock.h>
  21 #include <asm/hd64461.h>
  22 #include <mach/hp6xx.h>
  23 #include <cpu/dac.h>
  24
  25 MODULE_AUTHOR("Rafael Ignacio Zurita <rizurita@yahoo.com>");
  26 MODULE_DESCRIPTION("SuperH DAC audio driver");
  27 MODULE_LICENSE("GPL");
  28
  29 /* Module Parameters */
  30 static int index = SNDRV_DEFAULT_IDX1;
  31 static char *id = SNDRV_DEFAULT_STR1;
  32 module_param(index, int, 0444);
  33 MODULE_PARM_DESC(index, "Index value for SuperH DAC audio.");
  34 module_param(id, charp, 0444);
  35 MODULE_PARM_DESC(id, "ID string for SuperH DAC audio.");
  36
  37 /* main struct */
  38 struct snd_sh_dac {
  39         struct snd_card *card;
  40         struct snd_pcm_substream *substream;
  41         struct hrtimer hrtimer;
  42         ktime_t wakeups_per_second;
  43
  44         int rate;
  45         int empty;
  46         char *data_buffer, *buffer_begin, *buffer_end;
  47         int processed; /* bytes proccesed, to compare with period_size */
  48         int buffer_size;
  49         struct dac_audio_pdata *pdata;
  50 };
  51
  52
  53 static void dac_audio_start_timer(struct snd_sh_dac *chip)
  54 {
  55         hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
  56                       HRTIMER_MODE_REL);
  57 }
  58
  59 static void dac_audio_stop_timer(struct snd_sh_dac *chip)
  60 {
  61         hrtimer_cancel(&chip->hrtimer);
  62 }
  63
  64 static void dac_audio_reset(struct snd_sh_dac *chip)
  65 {
  66         dac_audio_stop_timer(chip);
  67         chip->buffer_begin = chip->buffer_end = chip->data_buffer;
  68         chip->processed = 0;
  69         chip->empty = 1;
  70 }
  71
  72 static void dac_audio_set_rate(struct snd_sh_dac *chip)
  73 {
  74         chip->wakeups_per_second = 1000000000 / chip->rate;
  75 }
  76
  77
  78 /* PCM INTERFACE */
  79
  80 static const struct snd_pcm_hardware snd_sh_dac_pcm_hw = {
  81         .info                   = (SNDRV_PCM_INFO_MMAP |
  82                                         SNDRV_PCM_INFO_MMAP_VALID |
  83                                         SNDRV_PCM_INFO_INTERLEAVED |
  84                                         SNDRV_PCM_INFO_HALF_DUPLEX),
  85         .formats                = SNDRV_PCM_FMTBIT_U8,
  86         .rates                  = SNDRV_PCM_RATE_8000,
  87         .rate_min               = 8000,
  88         .rate_max               = 8000,
  89         .channels_min           = 1,
  90         .channels_max           = 1,
  91         .buffer_bytes_max       = (48*1024),
  92         .period_bytes_min       = 1,
  93         .period_bytes_max       = (48*1024),
  94         .periods_min            = 1,
  95         .periods_max            = 1024,
  96 };
  97
  98 static int snd_sh_dac_pcm_open(struct snd_pcm_substream *substream)
  99 {
 100         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 101         struct snd_pcm_runtime *runtime = substream->runtime;
 102
 103         runtime->hw = snd_sh_dac_pcm_hw;
 104
 105         chip->substream = substream;
 106         chip->buffer_begin = chip->buffer_end = chip->data_buffer;
 107         chip->processed = 0;
 108         chip->empty = 1;
 109
 110         chip->pdata->start(chip->pdata);
 111
 112         return 0;
 113 }
 114
 115 static int snd_sh_dac_pcm_close(struct snd_pcm_substream *substream)
 116 {
 117         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 118
 119         chip->substream = NULL;
 120
 121         dac_audio_stop_timer(chip);
 122         chip->pdata->stop(chip->pdata);
 123
 124         return 0;
 125 }
 126
 127 static int snd_sh_dac_pcm_prepare(struct snd_pcm_substream *substream)
 128 {
 129         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 130         struct snd_pcm_runtime *runtime = chip->substream->runtime;
 131
 132         chip->buffer_size = runtime->buffer_size;
 133         memset(chip->data_buffer, 0, chip->pdata->buffer_size);
 134
 135         return 0;
 136 }
 137
 138 static int snd_sh_dac_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 139 {
 140         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 141
 142         switch (cmd) {
 143         case SNDRV_PCM_TRIGGER_START:
 144                 dac_audio_start_timer(chip);
 145                 break;
 146         case SNDRV_PCM_TRIGGER_STOP:
 147                 chip->buffer_begin = chip->buffer_end = chip->data_buffer;
 148                 chip->processed = 0;
 149                 chip->empty = 1;
 150                 dac_audio_stop_timer(chip);
 151                 break;
 152         default:
 153                  return -EINVAL;
 154         }
 155
 156         return 0;
 157 }
 158
 159 static int snd_sh_dac_pcm_copy(struct snd_pcm_substream *substream,
 160                                int channel, unsigned long pos,
 161                                struct iov_iter *src, unsigned long count)
 162 {
 163         /* channel is not used (interleaved data) */
 164         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 165
 166         if (copy_from_iter_toio(chip->data_buffer + pos, src, count))
 167                 return -EFAULT;
 168         chip->buffer_end = chip->data_buffer + pos + count;
 169
 170         if (chip->empty) {
 171                 chip->empty = 0;
 172                 dac_audio_start_timer(chip);
 173         }
 174
 175         return 0;
 176 }
 177
 178 static int snd_sh_dac_pcm_silence(struct snd_pcm_substream *substream,
 179                                   int channel, unsigned long pos,
 180                                   unsigned long count)
 181 {
 182         /* channel is not used (interleaved data) */
 183         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 184
 185         memset_io(chip->data_buffer + pos, 0, count);
 186         chip->buffer_end = chip->data_buffer + pos + count;
 187
 188         if (chip->empty) {
 189                 chip->empty = 0;
 190                 dac_audio_start_timer(chip);
 191         }
 192
 193         return 0;
 194 }
 195
 196 static
 197 snd_pcm_uframes_t snd_sh_dac_pcm_pointer(struct snd_pcm_substream *substream)
 198 {
 199         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 200         int pointer = chip->buffer_begin - chip->data_buffer;
 201
 202         return pointer;
 203 }
 204
 205 /* pcm ops */
 206 static const struct snd_pcm_ops snd_sh_dac_pcm_ops = {
 207         .open           = snd_sh_dac_pcm_open,
 208         .close          = snd_sh_dac_pcm_close,
 209         .prepare        = snd_sh_dac_pcm_prepare,
 210         .trigger        = snd_sh_dac_pcm_trigger,
 211         .pointer        = snd_sh_dac_pcm_pointer,
 212         .copy           = snd_sh_dac_pcm_copy,
 213         .fill_silence   = snd_sh_dac_pcm_silence,
 214         .mmap           = snd_pcm_lib_mmap_iomem,
 215 };
 216
 217 static int snd_sh_dac_pcm(struct snd_sh_dac *chip, int device)
 218 {
 219         int err;
 220         struct snd_pcm *pcm;
 221
 222         /* device should be always 0 for us */
 223         err = snd_pcm_new(chip->card, "SH_DAC PCM", device, 1, 0, &pcm);
 224         if (err < 0)
 225                 return err;
 226
 227         pcm->private_data = chip;
 228         strcpy(pcm->name, "SH_DAC PCM");
 229         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sh_dac_pcm_ops);
 230
 231         /* buffer size=48K */
 232         snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
 233                                        NULL, 48 * 1024, 48 * 1024);
 234
 235         return 0;
 236 }
 237 /* END OF PCM INTERFACE */
 238
 239
 240 /* driver .remove  --  destructor */
 241 static void snd_sh_dac_remove(struct platform_device *devptr)
 242 {
 243         snd_card_free(platform_get_drvdata(devptr));
 244 }
 245
 246 /* free -- it has been defined by create */
 247 static int snd_sh_dac_free(struct snd_sh_dac *chip)
 248 {
 249         /* release the data */
 250         kfree(chip->data_buffer);
 251         kfree(chip);
 252
 253         return 0;
 254 }
 255
 256 static int snd_sh_dac_dev_free(struct snd_device *device)
 257 {
 258         struct snd_sh_dac *chip = device->device_data;
 259
 260         return snd_sh_dac_free(chip);
 261 }
 262
 263 static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
 264 {
 265         struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac,
 266                                                hrtimer);
 267         struct snd_pcm_runtime *runtime = chip->substream->runtime;
 268         ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size);
 269
 270         if (!chip->empty) {
 271                 sh_dac_output(*chip->buffer_begin, chip->pdata->channel);
 272                 chip->buffer_begin++;
 273
 274                 chip->processed++;
 275                 if (chip->processed >= b_ps) {
 276                         chip->processed -= b_ps;
 277                         snd_pcm_period_elapsed(chip->substream);
 278                 }
 279
 280                 if (chip->buffer_begin == (chip->data_buffer +
 281                                            chip->buffer_size - 1))
 282                         chip->buffer_begin = chip->data_buffer;
 283
 284                 if (chip->buffer_begin == chip->buffer_end)
 285                         chip->empty = 1;
 286
 287         }
 288
 289         if (!chip->empty)
 290                 hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
 291                               HRTIMER_MODE_REL);
 292
 293         return HRTIMER_NORESTART;
 294 }
 295
 296 /* create  --  chip-specific constructor for the cards components */
 297 static int snd_sh_dac_create(struct snd_card *card,
 298                              struct platform_device *devptr,
 299                              struct snd_sh_dac **rchip)
 300 {
 301         struct snd_sh_dac *chip;
 302         int err;
 303
 304         static const struct snd_device_ops ops = {
 305                    .dev_free = snd_sh_dac_dev_free,
 306         };
 307
 308         *rchip = NULL;
 309
 310         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 311         if (chip == NULL)
 312                 return -ENOMEM;
 313
 314         chip->card = card;
 315
 316         hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 317         chip->hrtimer.function = sh_dac_audio_timer;
 318
 319         dac_audio_reset(chip);
 320         chip->rate = 8000;
 321         dac_audio_set_rate(chip);
 322
 323         chip->pdata = devptr->dev.platform_data;
 324
 325         chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL);
 326         if (chip->data_buffer == NULL) {
 327                 kfree(chip);
 328                 return -ENOMEM;
 329         }
 330
 331         err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
 332         if (err < 0) {
 333                 snd_sh_dac_free(chip);
 334                 return err;
 335         }
 336
 337         *rchip = chip;
 338
 339         return 0;
 340 }
 341
 342 /* driver .probe  --  constructor */
 343 static int snd_sh_dac_probe(struct platform_device *devptr)
 344 {
 345         struct snd_sh_dac *chip;
 346         struct snd_card *card;
 347         int err;
 348
 349         err = snd_card_new(&devptr->dev, index, id, THIS_MODULE, 0, &card);
 350         if (err < 0) {
 351                 dev_err(&devptr->dev, "cannot allocate the card\n");
 352                 return err;
 353         }
 354
 355         err = snd_sh_dac_create(card, devptr, &chip);
 356         if (err < 0)
 357                 goto probe_error;
 358
 359         err = snd_sh_dac_pcm(chip, 0);
 360         if (err < 0)
 361                 goto probe_error;
 362
 363         strcpy(card->driver, "snd_sh_dac");
 364         strcpy(card->shortname, "SuperH DAC audio driver");
 365         dev_info(&devptr->dev, "%s %s\n", card->longname, card->shortname);
 366
 367         err = snd_card_register(card);
 368         if (err < 0)
 369                 goto probe_error;
 370
 371         dev_info(&devptr->dev, "ALSA driver for SuperH DAC audio\n");
 372
 373         platform_set_drvdata(devptr, card);
 374         return 0;
 375
 376 probe_error:
 377         snd_card_free(card);
 378         return err;
 379 }
 380
 381 /*
 382  * "driver" definition
 383  */
 384 static struct platform_driver sh_dac_driver = {
 385         .probe  = snd_sh_dac_probe,
 386         .remove = snd_sh_dac_remove,
 387         .driver = {
 388                 .name = "dac_audio",
 389         },
 390 };
 391
 392 module_platform_driver(sh_dac_driver);