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); 418