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_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_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_io(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 .mmap = snd_pcm_lib_mmap_iomem, 215 }; 216 217 static int snd_sh_dac_pcm(struct snd_sh_dac *chip, int device) 218 { 219 int err; 220 struct snd_pcm *pcm; 221 222 /* device should be always 0 for us */ 223 err = snd_pcm_new(chip->card, "SH_DAC PCM", device, 1, 0, &pcm); 224 if (err < 0) 225 return err; 226 227 pcm->private_data = chip; 228 strcpy(pcm->name, "SH_DAC PCM"); 229 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sh_dac_pcm_ops); 230 231 /* buffer size=48K */ 232 snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS, 233 NULL, 48 * 1024, 48 * 1024); 234 235 return 0; 236 } 237 /* END OF PCM INTERFACE */ 238 239 240 /* driver .remove -- destructor */ 241 static void snd_sh_dac_remove(struct platform_device *devptr) 242 { 243 snd_card_free(platform_get_drvdata(devptr)); 244 } 245 246 /* free -- it has been defined by create */ 247 static int snd_sh_dac_free(struct snd_sh_dac *chip) 248 { 249 /* release the data */ 250 kfree(chip->data_buffer); 251 kfree(chip); 252 253 return 0; 254 } 255 256 static int snd_sh_dac_dev_free(struct snd_device *device) 257 { 258 struct snd_sh_dac *chip = device->device_data; 259 260 return snd_sh_dac_free(chip); 261 } 262 263 static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle) 264 { 265 struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac, 266 hrtimer); 267 struct snd_pcm_runtime *runtime = chip->substream->runtime; 268 ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size); 269 270 if (!chip->empty) { 271 sh_dac_output(*chip->buffer_begin, chip->pdata->channel); 272 chip->buffer_begin++; 273 274 chip->processed++; 275 if (chip->processed >= b_ps) { 276 chip->processed -= b_ps; 277 snd_pcm_period_elapsed(chip->substream); 278 } 279 280 if (chip->buffer_begin == (chip->data_buffer + 281 chip->buffer_size - 1)) 282 chip->buffer_begin = chip->data_buffer; 283 284 if (chip->buffer_begin == chip->buffer_end) 285 chip->empty = 1; 286 287 } 288 289 if (!chip->empty) 290 hrtimer_start(&chip->hrtimer, chip->wakeups_per_second, 291 HRTIMER_MODE_REL); 292 293 return HRTIMER_NORESTART; 294 } 295 296 /* create -- chip-specific constructor for the cards components */ 297 static int snd_sh_dac_create(struct snd_card *card, 298 struct platform_device *devptr, 299 struct snd_sh_dac **rchip) 300 { 301 struct snd_sh_dac *chip; 302 int err; 303 304 static const struct snd_device_ops ops = { 305 .dev_free = snd_sh_dac_dev_free, 306 }; 307 308 *rchip = NULL; 309 310 chip = kzalloc(sizeof(*chip), GFP_KERNEL); 311 if (chip == NULL) 312 return -ENOMEM; 313 314 chip->card = card; 315 316 hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 317 chip->hrtimer.function = sh_dac_audio_timer; 318 319 dac_audio_reset(chip); 320 chip->rate = 8000; 321 dac_audio_set_rate(chip); 322 323 chip->pdata = devptr->dev.platform_data; 324 325 chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL); 326 if (chip->data_buffer == NULL) { 327 kfree(chip); 328 return -ENOMEM; 329 } 330 331 err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops); 332 if (err < 0) { 333 snd_sh_dac_free(chip); 334 return err; 335 } 336 337 *rchip = chip; 338 339 return 0; 340 } 341 342 /* driver .probe -- constructor */ 343 static int snd_sh_dac_probe(struct platform_device *devptr) 344 { 345 struct snd_sh_dac *chip; 346 struct snd_card *card; 347 int err; 348 349 err = snd_card_new(&devptr->dev, index, id, THIS_MODULE, 0, &card); 350 if (err < 0) { 351 snd_printk(KERN_ERR "cannot allocate the card\n"); 352 return err; 353 } 354 355 err = snd_sh_dac_create(card, devptr, &chip); 356 if (err < 0) 357 goto probe_error; 358 359 err = snd_sh_dac_pcm(chip, 0); 360 if (err < 0) 361 goto probe_error; 362 363 strcpy(card->driver, "snd_sh_dac"); 364 strcpy(card->shortname, "SuperH DAC audio driver"); 365 printk(KERN_INFO "%s %s", card->longname, card->shortname); 366 367 err = snd_card_register(card); 368 if (err < 0) 369 goto probe_error; 370 371 snd_printk(KERN_INFO "ALSA driver for SuperH DAC audio"); 372 373 platform_set_drvdata(devptr, card); 374 return 0; 375 376 probe_error: 377 snd_card_free(card); 378 return err; 379 } 380 381 /* 382 * "driver" definition 383 */ 384 static struct platform_driver sh_dac_driver = { 385 .probe = snd_sh_dac_probe, 386 .remove_new = snd_sh_dac_remove, 387 .driver = { 388 .name = "dac_audio", 389 }, 390 }; 391 392 module_platform_driver(sh_dac_driver); 393