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         struct snd_pcm_runtime *runtime = substream->runtime;
 167
 168         if (copy_from_user_toio(chip->data_buffer + pos, src, count))
 169                 return -EFAULT;
 170         chip->buffer_end = chip->data_buffer + pos + count;
 171
 172         if (chip->empty) {
 173                 chip->empty = 0;
 174                 dac_audio_start_timer(chip);
 175         }
 176
 177         return 0;
 178 }
 179
 180 static int snd_sh_dac_pcm_copy_kernel(struct snd_pcm_substream *substream,
 181                                       int channel, unsigned long pos,
 182                                       void *src, unsigned long count)
 183 {
 184         /* channel is not used (interleaved data) */
 185         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 186         struct snd_pcm_runtime *runtime = substream->runtime;
 187
 188         memcpy_toio(chip->data_buffer + pos, src, count);
 189         chip->buffer_end = chip->data_buffer + pos + count;
 190
 191         if (chip->empty) {
 192                 chip->empty = 0;
 193                 dac_audio_start_timer(chip);
 194         }
 195
 196         return 0;
 197 }
 198
 199 static int snd_sh_dac_pcm_silence(struct snd_pcm_substream *substream,
 200                                   int channel, unsigned long pos,
 201                                   unsigned long count)
 202 {
 203         /* channel is not used (interleaved data) */
 204         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 205         struct snd_pcm_runtime *runtime = substream->runtime;
 206
 207         memset_io(chip->data_buffer + pos, 0, count);
 208         chip->buffer_end = chip->data_buffer + pos + count;
 209
 210         if (chip->empty) {
 211                 chip->empty = 0;
 212                 dac_audio_start_timer(chip);
 213         }
 214
 215         return 0;
 216 }
 217
 218 static
 219 snd_pcm_uframes_t snd_sh_dac_pcm_pointer(struct snd_pcm_substream *substream)
 220 {
 221         struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
 222         int pointer = chip->buffer_begin - chip->data_buffer;
 223
 224         return pointer;
 225 }
 226
 227 /* pcm ops */
 228 static const struct snd_pcm_ops snd_sh_dac_pcm_ops = {
 229         .open           = snd_sh_dac_pcm_open,
 230         .close          = snd_sh_dac_pcm_close,
 231         .ioctl          = snd_pcm_lib_ioctl,
 232         .prepare        = snd_sh_dac_pcm_prepare,
 233         .trigger        = snd_sh_dac_pcm_trigger,
 234         .pointer        = snd_sh_dac_pcm_pointer,
 235         .copy_user      = snd_sh_dac_pcm_copy,
 236         .copy_kernel    = snd_sh_dac_pcm_copy_kernel,
 237         .fill_silence   = snd_sh_dac_pcm_silence,
 238         .mmap           = snd_pcm_lib_mmap_iomem,
 239 };
 240
 241 static int snd_sh_dac_pcm(struct snd_sh_dac *chip, int device)
 242 {
 243         int err;
 244         struct snd_pcm *pcm;
 245
 246         /* device should be always 0 for us */
 247         err = snd_pcm_new(chip->card, "SH_DAC PCM", device, 1, 0, &pcm);
 248         if (err < 0)
 249                 return err;
 250
 251         pcm->private_data = chip;
 252         strcpy(pcm->name, "SH_DAC PCM");
 253         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sh_dac_pcm_ops);
 254
 255         /* buffer size=48K */
 256         snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
 257                                        NULL, 48 * 1024, 48 * 1024);
 258
 259         return 0;
 260 }
 261 /* END OF PCM INTERFACE */
 262
 263
 264 /* driver .remove  --  destructor */
 265 static int snd_sh_dac_remove(struct platform_device *devptr)
 266 {
 267         snd_card_free(platform_get_drvdata(devptr));
 268         return 0;
 269 }
 270
 271 /* free -- it has been defined by create */
 272 static int snd_sh_dac_free(struct snd_sh_dac *chip)
 273 {
 274         /* release the data */
 275         kfree(chip->data_buffer);
 276         kfree(chip);
 277
 278         return 0;
 279 }
 280
 281 static int snd_sh_dac_dev_free(struct snd_device *device)
 282 {
 283         struct snd_sh_dac *chip = device->device_data;
 284
 285         return snd_sh_dac_free(chip);
 286 }
 287
 288 static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
 289 {
 290         struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac,
 291                                                hrtimer);
 292         struct snd_pcm_runtime *runtime = chip->substream->runtime;
 293         ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size);
 294
 295         if (!chip->empty) {
 296                 sh_dac_output(*chip->buffer_begin, chip->pdata->channel);
 297                 chip->buffer_begin++;
 298
 299                 chip->processed++;
 300                 if (chip->processed >= b_ps) {
 301                         chip->processed -= b_ps;
 302                         snd_pcm_period_elapsed(chip->substream);
 303                 }
 304
 305                 if (chip->buffer_begin == (chip->data_buffer +
 306                                            chip->buffer_size - 1))
 307                         chip->buffer_begin = chip->data_buffer;
 308
 309                 if (chip->buffer_begin == chip->buffer_end)
 310                         chip->empty = 1;
 311
 312         }
 313
 314         if (!chip->empty)
 315                 hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
 316                               HRTIMER_MODE_REL);
 317
 318         return HRTIMER_NORESTART;
 319 }
 320
 321 /* create  --  chip-specific constructor for the cards components */
 322 static int snd_sh_dac_create(struct snd_card *card,
 323                              struct platform_device *devptr,
 324                              struct snd_sh_dac **rchip)
 325 {
 326         struct snd_sh_dac *chip;
 327         int err;
 328
 329         static struct snd_device_ops ops = {
 330                    .dev_free = snd_sh_dac_dev_free,
 331         };
 332
 333         *rchip = NULL;
 334
 335         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 336         if (chip == NULL)
 337                 return -ENOMEM;
 338
 339         chip->card = card;
 340
 341         hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 342         chip->hrtimer.function = sh_dac_audio_timer;
 343
 344         dac_audio_reset(chip);
 345         chip->rate = 8000;
 346         dac_audio_set_rate(chip);
 347
 348         chip->pdata = devptr->dev.platform_data;
 349
 350         chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL);
 351         if (chip->data_buffer == NULL) {
 352                 kfree(chip);
 353                 return -ENOMEM;
 354         }
 355
 356         err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
 357         if (err < 0) {
 358                 snd_sh_dac_free(chip);
 359                 return err;
 360         }
 361
 362         *rchip = chip;
 363
 364         return 0;
 365 }
 366
 367 /* driver .probe  --  constructor */
 368 static int snd_sh_dac_probe(struct platform_device *devptr)
 369 {
 370         struct snd_sh_dac *chip;
 371         struct snd_card *card;
 372         int err;
 373
 374         err = snd_card_new(&devptr->dev, index, id, THIS_MODULE, 0, &card);
 375         if (err < 0) {
 376                         snd_printk(KERN_ERR "cannot allocate the card\n");
 377                         return err;
 378         }
 379
 380         err = snd_sh_dac_create(card, devptr, &chip);
 381         if (err < 0)
 382                 goto probe_error;
 383
 384         err = snd_sh_dac_pcm(chip, 0);
 385         if (err < 0)
 386                 goto probe_error;
 387
 388         strcpy(card->driver, "snd_sh_dac");
 389         strcpy(card->shortname, "SuperH DAC audio driver");
 390         printk(KERN_INFO "%s %s", card->longname, card->shortname);
 391
 392         err = snd_card_register(card);
 393         if (err < 0)
 394                 goto probe_error;
 395
 396         snd_printk(KERN_INFO "ALSA driver for SuperH DAC audio");
 397
 398         platform_set_drvdata(devptr, card);
 399         return 0;
 400
 401 probe_error:
 402         snd_card_free(card);
 403         return err;
 404 }
 405
 406 /*
 407  * "driver" definition
 408  */
 409 static struct platform_driver sh_dac_driver = {
 410         .probe  = snd_sh_dac_probe,
 411         .remove = snd_sh_dac_remove,
 412         .driver = {
 413                 .name = "dac_audio",
 414         },
 415 };
 416
 417 module_platform_driver(sh_dac_driver);