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                                void __user *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_user_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_copy_kernel(struct snd_pcm_substream *substream,
 179                                       int channel, unsigned long pos,
 180                                       void *src, unsigned long count)
 181 {
 182         /* channel is not used (interleaved data) */
 183         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 184
 185         memcpy_toio(chip->data_buffer + pos, src, 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 int snd_sh_dac_pcm_silence(struct snd_pcm_substream *substream,
 197                                   int channel, unsigned long pos,
 198                                   unsigned long count)
 199 {
 200         /* channel is not used (interleaved data) */
 201         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 202
 203         memset_io(chip->data_buffer + pos, 0, count);
 204         chip->buffer_end = chip->data_buffer + pos + count;
 205
 206         if (chip->empty) {
 207                 chip->empty = 0;
 208                 dac_audio_start_timer(chip);
 209         }
 210
 211         return 0;
 212 }
 213
 214 static
 215 snd_pcm_uframes_t snd_sh_dac_pcm_pointer(struct snd_pcm_substream *substream)
 216 {
 217         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 218         int pointer = chip->buffer_begin - chip->data_buffer;
 219
 220         return pointer;
 221 }
 222
 223 /* pcm ops */
 224 static const struct snd_pcm_ops snd_sh_dac_pcm_ops = {
 225         .open           = snd_sh_dac_pcm_open,
 226         .close          = snd_sh_dac_pcm_close,
 227         .prepare        = snd_sh_dac_pcm_prepare,
 228         .trigger        = snd_sh_dac_pcm_trigger,
 229         .pointer        = snd_sh_dac_pcm_pointer,
 230         .copy_user      = snd_sh_dac_pcm_copy,
 231         .copy_kernel    = snd_sh_dac_pcm_copy_kernel,
 232         .fill_silence   = snd_sh_dac_pcm_silence,
 233         .mmap           = snd_pcm_lib_mmap_iomem,
 234 };
 235
 236 static int snd_sh_dac_pcm(struct snd_sh_dac *chip, int device)
 237 {
 238         int err;
 239         struct snd_pcm *pcm;
 240
 241         /* device should be always 0 for us */
 242         err = snd_pcm_new(chip->card, "SH_DAC PCM", device, 1, 0, &pcm);
 243         if (err < 0)
 244                 return err;
 245
 246         pcm->private_data = chip;
 247         strcpy(pcm->name, "SH_DAC PCM");
 248         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sh_dac_pcm_ops);
 249
 250         /* buffer size=48K */
 251         snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
 252                                        NULL, 48 * 1024, 48 * 1024);
 253
 254         return 0;
 255 }
 256 /* END OF PCM INTERFACE */
 257
 258
 259 /* driver .remove  --  destructor */
 260 static int snd_sh_dac_remove(struct platform_device *devptr)
 261 {
 262         snd_card_free(platform_get_drvdata(devptr));
 263         return 0;
 264 }
 265
 266 /* free -- it has been defined by create */
 267 static int snd_sh_dac_free(struct snd_sh_dac *chip)
 268 {
 269         /* release the data */
 270         kfree(chip->data_buffer);
 271         kfree(chip);
 272
 273         return 0;
 274 }
 275
 276 static int snd_sh_dac_dev_free(struct snd_device *device)
 277 {
 278         struct snd_sh_dac *chip = device->device_data;
 279
 280         return snd_sh_dac_free(chip);
 281 }
 282
 283 static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
 284 {
 285         struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac,
 286                                                hrtimer);
 287         struct snd_pcm_runtime *runtime = chip->substream->runtime;
 288         ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size);
 289
 290         if (!chip->empty) {
 291                 sh_dac_output(*chip->buffer_begin, chip->pdata->channel);
 292                 chip->buffer_begin++;
 293
 294                 chip->processed++;
 295                 if (chip->processed >= b_ps) {
 296                         chip->processed -= b_ps;
 297                         snd_pcm_period_elapsed(chip->substream);
 298                 }
 299
 300                 if (chip->buffer_begin == (chip->data_buffer +
 301                                            chip->buffer_size - 1))
 302                         chip->buffer_begin = chip->data_buffer;
 303
 304                 if (chip->buffer_begin == chip->buffer_end)
 305                         chip->empty = 1;
 306
 307         }
 308
 309         if (!chip->empty)
 310                 hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
 311                               HRTIMER_MODE_REL);
 312
 313         return HRTIMER_NORESTART;
 314 }
 315
 316 /* create  --  chip-specific constructor for the cards components */
 317 static int snd_sh_dac_create(struct snd_card *card,
 318                              struct platform_device *devptr,
 319                              struct snd_sh_dac **rchip)
 320 {
 321         struct snd_sh_dac *chip;
 322         int err;
 323
 324         static const struct snd_device_ops ops = {
 325                    .dev_free = snd_sh_dac_dev_free,
 326         };
 327
 328         *rchip = NULL;
 329
 330         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 331         if (chip == NULL)
 332                 return -ENOMEM;
 333
 334         chip->card = card;
 335
 336         hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 337         chip->hrtimer.function = sh_dac_audio_timer;
 338
 339         dac_audio_reset(chip);
 340         chip->rate = 8000;
 341         dac_audio_set_rate(chip);
 342
 343         chip->pdata = devptr->dev.platform_data;
 344
 345         chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL);
 346         if (chip->data_buffer == NULL) {
 347                 kfree(chip);
 348                 return -ENOMEM;
 349         }
 350
 351         err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
 352         if (err < 0) {
 353                 snd_sh_dac_free(chip);
 354                 return err;
 355         }
 356
 357         *rchip = chip;
 358
 359         return 0;
 360 }
 361
 362 /* driver .probe  --  constructor */
 363 static int snd_sh_dac_probe(struct platform_device *devptr)
 364 {
 365         struct snd_sh_dac *chip;
 366         struct snd_card *card;
 367         int err;
 368
 369         err = snd_card_new(&devptr->dev, index, id, THIS_MODULE, 0, &card);
 370         if (err < 0) {
 371                         snd_printk(KERN_ERR "cannot allocate the card\n");
 372                         return err;
 373         }
 374
 375         err = snd_sh_dac_create(card, devptr, &chip);
 376         if (err < 0)
 377                 goto probe_error;
 378
 379         err = snd_sh_dac_pcm(chip, 0);
 380         if (err < 0)
 381                 goto probe_error;
 382
 383         strcpy(card->driver, "snd_sh_dac");
 384         strcpy(card->shortname, "SuperH DAC audio driver");
 385         printk(KERN_INFO "%s %s", card->longname, card->shortname);
 386
 387         err = snd_card_register(card);
 388         if (err < 0)
 389                 goto probe_error;
 390
 391         snd_printk(KERN_INFO "ALSA driver for SuperH DAC audio");
 392
 393         platform_set_drvdata(devptr, card);
 394         return 0;
 395
 396 probe_error:
 397         snd_card_free(card);
 398         return err;
 399 }
 400
 401 /*
 402  * "driver" definition
 403  */
 404 static struct platform_driver sh_dac_driver = {
 405         .probe  = snd_sh_dac_probe,
 406         .remove = snd_sh_dac_remove,
 407         .driver = {
 408                 .name = "dac_audio",
 409         },
 410 };
 411
 412 module_platform_driver(sh_dac_driver);