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 void snd_sh_dac_remove(struct platform_device *devptr) 261 { 262 snd_card_free(platform_get_drvdata(devptr)); 263 } 264 265 /* free -- it has been defined by create */ 266 static int snd_sh_dac_free(struct snd_sh_dac *chip) 267 { 268 /* release the data */ 269 kfree(chip->data_buffer); 270 kfree(chip); 271 272 return 0; 273 } 274 275 static int snd_sh_dac_dev_free(struct snd_device *device) 276 { 277 struct snd_sh_dac *chip = device->device_data; 278 279 return snd_sh_dac_free(chip); 280 } 281 282 static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle) 283 { 284 struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac, 285 hrtimer); 286 struct snd_pcm_runtime *runtime = chip->substream->runtime; 287 ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size); 288 289 if (!chip->empty) { 290 sh_dac_output(*chip->buffer_begin, chip->pdata->channel); 291 chip->buffer_begin++; 292 293 chip->processed++; 294 if (chip->processed >= b_ps) { 295 chip->processed -= b_ps; 296 snd_pcm_period_elapsed(chip->substream); 297 } 298 299 if (chip->buffer_begin == (chip->data_buffer + 300 chip->buffer_size - 1)) 301 chip->buffer_begin = chip->data_buffer; 302 303 if (chip->buffer_begin == chip->buffer_end) 304 chip->empty = 1; 305 306 } 307 308 if (!chip->empty) 309 hrtimer_start(&chip->hrtimer, chip->wakeups_per_second, 310 HRTIMER_MODE_REL); 311 312 return HRTIMER_NORESTART; 313 } 314 315 /* create -- chip-specific constructor for the cards components */ 316 static int snd_sh_dac_create(struct snd_card *card, 317 struct platform_device *devptr, 318 struct snd_sh_dac **rchip) 319 { 320 struct snd_sh_dac *chip; 321 int err; 322 323 static const struct snd_device_ops ops = { 324 .dev_free = snd_sh_dac_dev_free, 325 }; 326 327 *rchip = NULL; 328 329 chip = kzalloc(sizeof(*chip), GFP_KERNEL); 330 if (chip == NULL) 331 return -ENOMEM; 332 333 chip->card = card; 334 335 hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 336 chip->hrtimer.function = sh_dac_audio_timer; 337 338 dac_audio_reset(chip); 339 chip->rate = 8000; 340 dac_audio_set_rate(chip); 341 342 chip->pdata = devptr->dev.platform_data; 343 344 chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL); 345 if (chip->data_buffer == NULL) { 346 kfree(chip); 347 return -ENOMEM; 348 } 349 350 err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops); 351 if (err < 0) { 352 snd_sh_dac_free(chip); 353 return err; 354 } 355 356 *rchip = chip; 357 358 return 0; 359 } 360 361 /* driver .probe -- constructor */ 362 static int snd_sh_dac_probe(struct platform_device *devptr) 363 { 364 struct snd_sh_dac *chip; 365 struct snd_card *card; 366 int err; 367 368 err = snd_card_new(&devptr->dev, index, id, THIS_MODULE, 0, &card); 369 if (err < 0) { 370 snd_printk(KERN_ERR "cannot allocate the card\n"); 371 return err; 372 } 373 374 err = snd_sh_dac_create(card, devptr, &chip); 375 if (err < 0) 376 goto probe_error; 377 378 err = snd_sh_dac_pcm(chip, 0); 379 if (err < 0) 380 goto probe_error; 381 382 strcpy(card->driver, "snd_sh_dac"); 383 strcpy(card->shortname, "SuperH DAC audio driver"); 384 printk(KERN_INFO "%s %s", card->longname, card->shortname); 385 386 err = snd_card_register(card); 387 if (err < 0) 388 goto probe_error; 389 390 snd_printk(KERN_INFO "ALSA driver for SuperH DAC audio"); 391 392 platform_set_drvdata(devptr, card); 393 return 0; 394 395 probe_error: 396 snd_card_free(card); 397 return err; 398 } 399 400 /* 401 * "driver" definition 402 */ 403 static struct platform_driver sh_dac_driver = { 404 .probe = snd_sh_dac_probe, 405 .remove_new = snd_sh_dac_remove, 406 .driver = { 407 .name = "dac_audio", 408 }, 409 }; 410 411 module_platform_driver(sh_dac_driver); 412