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