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 MODULE_SUPPORTED_DEVICE("{{SuperH DAC audio support}}");
  29
  30 /* Module Parameters */
  31 static int index = SNDRV_DEFAULT_IDX1;
  32 static char *id = SNDRV_DEFAULT_STR1;
  33 module_param(index, int, 0444);
  34 MODULE_PARM_DESC(index, "Index value for SuperH DAC audio.");
  35 module_param(id, charp, 0444);
  36 MODULE_PARM_DESC(id, "ID string for SuperH DAC audio.");
  37
  38 /* main struct */
  39 struct snd_sh_dac {
  40         struct snd_card *card;
  41         struct snd_pcm_substream *substream;
  42         struct hrtimer hrtimer;
  43         ktime_t wakeups_per_second;
  44
  45         int rate;
  46         int empty;
  47         char *data_buffer, *buffer_begin, *buffer_end;
  48         int processed; /* bytes proccesed, to compare with period_size */
  49         int buffer_size;
  50         struct dac_audio_pdata *pdata;
  51 };
  52
  53
  54 static void dac_audio_start_timer(struct snd_sh_dac *chip)
  55 {
  56         hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
  57                       HRTIMER_MODE_REL);
  58 }
  59
  60 static void dac_audio_stop_timer(struct snd_sh_dac *chip)
  61 {
  62         hrtimer_cancel(&chip->hrtimer);
  63 }
  64
  65 static void dac_audio_reset(struct snd_sh_dac *chip)
  66 {
  67         dac_audio_stop_timer(chip);
  68         chip->buffer_begin = chip->buffer_end = chip->data_buffer;
  69         chip->processed = 0;
  70         chip->empty = 1;
  71 }
  72
  73 static void dac_audio_set_rate(struct snd_sh_dac *chip)
  74 {
  75         chip->wakeups_per_second = 1000000000 / chip->rate;
  76 }
  77
  78
  79 /* PCM INTERFACE */
  80
  81 static const struct snd_pcm_hardware snd_sh_dac_pcm_hw = {
  82         .info                   = (SNDRV_PCM_INFO_MMAP |
  83                                         SNDRV_PCM_INFO_MMAP_VALID |
  84                                         SNDRV_PCM_INFO_INTERLEAVED |
  85                                         SNDRV_PCM_INFO_HALF_DUPLEX),
  86         .formats                = SNDRV_PCM_FMTBIT_U8,
  87         .rates                  = SNDRV_PCM_RATE_8000,
  88         .rate_min               = 8000,
  89         .rate_max               = 8000,
  90         .channels_min           = 1,
  91         .channels_max           = 1,
  92         .buffer_bytes_max       = (48*1024),
  93         .period_bytes_min       = 1,
  94         .period_bytes_max       = (48*1024),
  95         .periods_min            = 1,
  96         .periods_max            = 1024,
  97 };
  98
  99 static int snd_sh_dac_pcm_open(struct snd_pcm_substream *substream)
 100 {
 101         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 102         struct snd_pcm_runtime *runtime = substream->runtime;
 103
 104         runtime->hw = snd_sh_dac_pcm_hw;
 105
 106         chip->substream = substream;
 107         chip->buffer_begin = chip->buffer_end = chip->data_buffer;
 108         chip->processed = 0;
 109         chip->empty = 1;
 110
 111         chip->pdata->start(chip->pdata);
 112
 113         return 0;
 114 }
 115
 116 static int snd_sh_dac_pcm_close(struct snd_pcm_substream *substream)
 117 {
 118         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 119
 120         chip->substream = NULL;
 121
 122         dac_audio_stop_timer(chip);
 123         chip->pdata->stop(chip->pdata);
 124
 125         return 0;
 126 }
 127
 128 static int snd_sh_dac_pcm_prepare(struct snd_pcm_substream *substream)
 129 {
 130         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 131         struct snd_pcm_runtime *runtime = chip->substream->runtime;
 132
 133         chip->buffer_size = runtime->buffer_size;
 134         memset(chip->data_buffer, 0, chip->pdata->buffer_size);
 135
 136         return 0;
 137 }
 138
 139 static int snd_sh_dac_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 140 {
 141         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 142
 143         switch (cmd) {
 144         case SNDRV_PCM_TRIGGER_START:
 145                 dac_audio_start_timer(chip);
 146                 break;
 147         case SNDRV_PCM_TRIGGER_STOP:
 148                 chip->buffer_begin = chip->buffer_end = chip->data_buffer;
 149                 chip->processed = 0;
 150                 chip->empty = 1;
 151                 dac_audio_stop_timer(chip);
 152                 break;
 153         default:
 154                  return -EINVAL;
 155         }
 156
 157         return 0;
 158 }
 159
 160 static int snd_sh_dac_pcm_copy(struct snd_pcm_substream *substream,
 161                                int channel, unsigned long pos,
 162                                void __user *src, unsigned long count)
 163 {
 164         /* channel is not used (interleaved data) */
 165         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 166
 167         if (copy_from_user_toio(chip->data_buffer + pos, src, count))
 168                 return -EFAULT;
 169         chip->buffer_end = chip->data_buffer + pos + count;
 170
 171         if (chip->empty) {
 172                 chip->empty = 0;
 173                 dac_audio_start_timer(chip);
 174         }
 175
 176         return 0;
 177 }
 178
 179 static int snd_sh_dac_pcm_copy_kernel(struct snd_pcm_substream *substream,
 180                                       int channel, unsigned long pos,
 181                                       void *src, unsigned long count)
 182 {
 183         /* channel is not used (interleaved data) */
 184         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 185
 186         memcpy_toio(chip->data_buffer + pos, src, count);
 187         chip->buffer_end = chip->data_buffer + pos + count;
 188
 189         if (chip->empty) {
 190                 chip->empty = 0;
 191                 dac_audio_start_timer(chip);
 192         }
 193
 194         return 0;
 195 }
 196
 197 static int snd_sh_dac_pcm_silence(struct snd_pcm_substream *substream,
 198                                   int channel, unsigned long pos,
 199                                   unsigned long count)
 200 {
 201         /* channel is not used (interleaved data) */
 202         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 203
 204         memset_io(chip->data_buffer + pos, 0, count);
 205         chip->buffer_end = chip->data_buffer + pos + count;
 206
 207         if (chip->empty) {
 208                 chip->empty = 0;
 209                 dac_audio_start_timer(chip);
 210         }
 211
 212         return 0;
 213 }
 214
 215 static
 216 snd_pcm_uframes_t snd_sh_dac_pcm_pointer(struct snd_pcm_substream *substream)
 217 {
 218         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 219         int pointer = chip->buffer_begin - chip->data_buffer;
 220
 221         return pointer;
 222 }
 223
 224 /* pcm ops */
 225 static const struct snd_pcm_ops snd_sh_dac_pcm_ops = {
 226         .open           = snd_sh_dac_pcm_open,
 227         .close          = snd_sh_dac_pcm_close,
 228         .prepare        = snd_sh_dac_pcm_prepare,
 229         .trigger        = snd_sh_dac_pcm_trigger,
 230         .pointer        = snd_sh_dac_pcm_pointer,
 231         .copy_user      = snd_sh_dac_pcm_copy,
 232         .copy_kernel    = snd_sh_dac_pcm_copy_kernel,
 233         .fill_silence   = snd_sh_dac_pcm_silence,
 234         .mmap           = snd_pcm_lib_mmap_iomem,
 235 };
 236
 237 static int snd_sh_dac_pcm(struct snd_sh_dac *chip, int device)
 238 {
 239         int err;
 240         struct snd_pcm *pcm;
 241
 242         /* device should be always 0 for us */
 243         err = snd_pcm_new(chip->card, "SH_DAC PCM", device, 1, 0, &pcm);
 244         if (err < 0)
 245                 return err;
 246
 247         pcm->private_data = chip;
 248         strcpy(pcm->name, "SH_DAC PCM");
 249         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sh_dac_pcm_ops);
 250
 251         /* buffer size=48K */
 252         snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
 253                                        NULL, 48 * 1024, 48 * 1024);
 254
 255         return 0;
 256 }
 257 /* END OF PCM INTERFACE */
 258
 259
 260 /* driver .remove  --  destructor */
 261 static int snd_sh_dac_remove(struct platform_device *devptr)
 262 {
 263         snd_card_free(platform_get_drvdata(devptr));
 264         return 0;
 265 }
 266
 267 /* free -- it has been defined by create */
 268 static int snd_sh_dac_free(struct snd_sh_dac *chip)
 269 {
 270         /* release the data */
 271         kfree(chip->data_buffer);
 272         kfree(chip);
 273
 274         return 0;
 275 }
 276
 277 static int snd_sh_dac_dev_free(struct snd_device *device)
 278 {
 279         struct snd_sh_dac *chip = device->device_data;
 280
 281         return snd_sh_dac_free(chip);
 282 }
 283
 284 static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
 285 {
 286         struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac,
 287                                                hrtimer);
 288         struct snd_pcm_runtime *runtime = chip->substream->runtime;
 289         ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size);
 290
 291         if (!chip->empty) {
 292                 sh_dac_output(*chip->buffer_begin, chip->pdata->channel);
 293                 chip->buffer_begin++;
 294
 295                 chip->processed++;
 296                 if (chip->processed >= b_ps) {
 297                         chip->processed -= b_ps;
 298                         snd_pcm_period_elapsed(chip->substream);
 299                 }
 300
 301                 if (chip->buffer_begin == (chip->data_buffer +
 302                                            chip->buffer_size - 1))
 303                         chip->buffer_begin = chip->data_buffer;
 304
 305                 if (chip->buffer_begin == chip->buffer_end)
 306                         chip->empty = 1;
 307
 308         }
 309
 310         if (!chip->empty)
 311                 hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
 312                               HRTIMER_MODE_REL);
 313
 314         return HRTIMER_NORESTART;
 315 }
 316
 317 /* create  --  chip-specific constructor for the cards components */
 318 static int snd_sh_dac_create(struct snd_card *card,
 319                              struct platform_device *devptr,
 320                              struct snd_sh_dac **rchip)
 321 {
 322         struct snd_sh_dac *chip;
 323         int err;
 324
 325         static const struct snd_device_ops ops = {
 326                    .dev_free = snd_sh_dac_dev_free,
 327         };
 328
 329         *rchip = NULL;
 330
 331         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 332         if (chip == NULL)
 333                 return -ENOMEM;
 334
 335         chip->card = card;
 336
 337         hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 338         chip->hrtimer.function = sh_dac_audio_timer;
 339
 340         dac_audio_reset(chip);
 341         chip->rate = 8000;
 342         dac_audio_set_rate(chip);
 343
 344         chip->pdata = devptr->dev.platform_data;
 345
 346         chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL);
 347         if (chip->data_buffer == NULL) {
 348                 kfree(chip);
 349                 return -ENOMEM;
 350         }
 351
 352         err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
 353         if (err < 0) {
 354                 snd_sh_dac_free(chip);
 355                 return err;
 356         }
 357
 358         *rchip = chip;
 359
 360         return 0;
 361 }
 362
 363 /* driver .probe  --  constructor */
 364 static int snd_sh_dac_probe(struct platform_device *devptr)
 365 {
 366         struct snd_sh_dac *chip;
 367         struct snd_card *card;
 368         int err;
 369
 370         err = snd_card_new(&devptr->dev, index, id, THIS_MODULE, 0, &card);
 371         if (err < 0) {
 372                         snd_printk(KERN_ERR "cannot allocate the card\n");
 373                         return err;
 374         }
 375
 376         err = snd_sh_dac_create(card, devptr, &chip);
 377         if (err < 0)
 378                 goto probe_error;
 379
 380         err = snd_sh_dac_pcm(chip, 0);
 381         if (err < 0)
 382                 goto probe_error;
 383
 384         strcpy(card->driver, "snd_sh_dac");
 385         strcpy(card->shortname, "SuperH DAC audio driver");
 386         printk(KERN_INFO "%s %s", card->longname, card->shortname);
 387
 388         err = snd_card_register(card);
 389         if (err < 0)
 390                 goto probe_error;
 391
 392         snd_printk(KERN_INFO "ALSA driver for SuperH DAC audio");
 393
 394         platform_set_drvdata(devptr, card);
 395         return 0;
 396
 397 probe_error:
 398         snd_card_free(card);
 399         return err;
 400 }
 401
 402 /*
 403  * "driver" definition
 404  */
 405 static struct platform_driver sh_dac_driver = {
 406         .probe  = snd_sh_dac_probe,
 407         .remove = snd_sh_dac_remove,
 408         .driver = {
 409                 .name = "dac_audio",
 410         },
 411 };
 412
 413 module_platform_driver(sh_dac_driver);