1 /* 2 * Copyright (C) 2013, Analog Devices Inc. 3 * Author: Lars-Peter Clausen <lars@metafoo.de> 4 * 5 * This program is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License as published by the 7 * Free Software Foundation; either version 2 of the License, or (at your 8 * option) any later version. 9 * 10 * You should have received a copy of the GNU General Public License along 11 * with this program; if not, write to the Free Software Foundation, Inc., 12 * 675 Mass Ave, Cambridge, MA 02139, USA. 13 * 14 */ 15 #include <linux/module.h> 16 #include <linux/init.h> 17 #include <linux/dmaengine.h> 18 #include <linux/slab.h> 19 #include <sound/pcm.h> 20 #include <sound/pcm_params.h> 21 #include <sound/soc.h> 22 #include <linux/dma-mapping.h> 23 #include <linux/of.h> 24 25 #include <sound/dmaengine_pcm.h> 26 27 /* 28 * The platforms dmaengine driver does not support reporting the amount of 29 * bytes that are still left to transfer. 30 */ 31 #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31) 32 33 struct dmaengine_pcm { 34 struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1]; 35 const struct snd_dmaengine_pcm_config *config; 36 struct snd_soc_component component; 37 unsigned int flags; 38 }; 39 40 static struct dmaengine_pcm *soc_component_to_pcm(struct snd_soc_component *p) 41 { 42 return container_of(p, struct dmaengine_pcm, component); 43 } 44 45 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm, 46 struct snd_pcm_substream *substream) 47 { 48 if (!pcm->chan[substream->stream]) 49 return NULL; 50 51 return pcm->chan[substream->stream]->device->dev; 52 } 53 54 /** 55 * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback 56 * @substream: PCM substream 57 * @params: hw_params 58 * @slave_config: DMA slave config to prepare 59 * 60 * This function can be used as a generic prepare_slave_config callback for 61 * platforms which make use of the snd_dmaengine_dai_dma_data struct for their 62 * DAI DMA data. Internally the function will first call 63 * snd_hwparams_to_dma_slave_config to fill in the slave config based on the 64 * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the 65 * remaining fields based on the DAI DMA data. 66 */ 67 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream, 68 struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config) 69 { 70 struct snd_soc_pcm_runtime *rtd = substream->private_data; 71 struct snd_dmaengine_dai_dma_data *dma_data; 72 int ret; 73 74 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 75 76 ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config); 77 if (ret) 78 return ret; 79 80 snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data, 81 slave_config); 82 83 return 0; 84 } 85 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config); 86 87 static int dmaengine_pcm_hw_params(struct snd_pcm_substream *substream, 88 struct snd_pcm_hw_params *params) 89 { 90 struct snd_soc_pcm_runtime *rtd = substream->private_data; 91 struct snd_soc_component *component = 92 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 93 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 94 struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream); 95 int (*prepare_slave_config)(struct snd_pcm_substream *substream, 96 struct snd_pcm_hw_params *params, 97 struct dma_slave_config *slave_config); 98 struct dma_slave_config slave_config; 99 int ret; 100 101 memset(&slave_config, 0, sizeof(slave_config)); 102 103 if (!pcm->config) 104 prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config; 105 else 106 prepare_slave_config = pcm->config->prepare_slave_config; 107 108 if (prepare_slave_config) { 109 ret = prepare_slave_config(substream, params, &slave_config); 110 if (ret) 111 return ret; 112 113 ret = dmaengine_slave_config(chan, &slave_config); 114 if (ret) 115 return ret; 116 } 117 118 return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params)); 119 } 120 121 static int dmaengine_pcm_set_runtime_hwparams(struct snd_pcm_substream *substream) 122 { 123 struct snd_soc_pcm_runtime *rtd = substream->private_data; 124 struct snd_soc_component *component = 125 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 126 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 127 struct device *dma_dev = dmaengine_dma_dev(pcm, substream); 128 struct dma_chan *chan = pcm->chan[substream->stream]; 129 struct snd_dmaengine_dai_dma_data *dma_data; 130 struct dma_slave_caps dma_caps; 131 struct snd_pcm_hardware hw; 132 u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | 133 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | 134 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); 135 snd_pcm_format_t i; 136 int ret; 137 138 if (pcm->config && pcm->config->pcm_hardware) 139 return snd_soc_set_runtime_hwparams(substream, 140 pcm->config->pcm_hardware); 141 142 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 143 144 memset(&hw, 0, sizeof(hw)); 145 hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | 146 SNDRV_PCM_INFO_INTERLEAVED; 147 hw.periods_min = 2; 148 hw.periods_max = UINT_MAX; 149 hw.period_bytes_min = 256; 150 hw.period_bytes_max = dma_get_max_seg_size(dma_dev); 151 hw.buffer_bytes_max = SIZE_MAX; 152 hw.fifo_size = dma_data->fifo_size; 153 154 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 155 hw.info |= SNDRV_PCM_INFO_BATCH; 156 157 ret = dma_get_slave_caps(chan, &dma_caps); 158 if (ret == 0) { 159 if (dma_caps.cmd_pause) 160 hw.info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME; 161 if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT) 162 hw.info |= SNDRV_PCM_INFO_BATCH; 163 164 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) 165 addr_widths = dma_caps.dst_addr_widths; 166 else 167 addr_widths = dma_caps.src_addr_widths; 168 } 169 170 /* 171 * If SND_DMAENGINE_PCM_DAI_FLAG_PACK is set keep 172 * hw.formats set to 0, meaning no restrictions are in place. 173 * In this case it's the responsibility of the DAI driver to 174 * provide the supported format information. 175 */ 176 if (!(dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)) 177 /* 178 * Prepare formats mask for valid/allowed sample types. If the 179 * dma does not have support for the given physical word size, 180 * it needs to be masked out so user space can not use the 181 * format which produces corrupted audio. 182 * In case the dma driver does not implement the slave_caps the 183 * default assumption is that it supports 1, 2 and 4 bytes 184 * widths. 185 */ 186 for (i = SNDRV_PCM_FORMAT_FIRST; i <= SNDRV_PCM_FORMAT_LAST; i++) { 187 int bits = snd_pcm_format_physical_width(i); 188 189 /* 190 * Enable only samples with DMA supported physical 191 * widths 192 */ 193 switch (bits) { 194 case 8: 195 case 16: 196 case 24: 197 case 32: 198 case 64: 199 if (addr_widths & (1 << (bits / 8))) 200 hw.formats |= (1LL << i); 201 break; 202 default: 203 /* Unsupported types */ 204 break; 205 } 206 } 207 208 return snd_soc_set_runtime_hwparams(substream, &hw); 209 } 210 211 static int dmaengine_pcm_open(struct snd_pcm_substream *substream) 212 { 213 struct snd_soc_pcm_runtime *rtd = substream->private_data; 214 struct snd_soc_component *component = 215 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 216 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 217 struct dma_chan *chan = pcm->chan[substream->stream]; 218 int ret; 219 220 ret = dmaengine_pcm_set_runtime_hwparams(substream); 221 if (ret) 222 return ret; 223 224 return snd_dmaengine_pcm_open(substream, chan); 225 } 226 227 static struct dma_chan *dmaengine_pcm_compat_request_channel( 228 struct snd_soc_pcm_runtime *rtd, 229 struct snd_pcm_substream *substream) 230 { 231 struct snd_soc_component *component = 232 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 233 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 234 struct snd_dmaengine_dai_dma_data *dma_data; 235 dma_filter_fn fn = NULL; 236 237 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 238 239 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0]) 240 return pcm->chan[0]; 241 242 if (pcm->config && pcm->config->compat_request_channel) 243 return pcm->config->compat_request_channel(rtd, substream); 244 245 if (pcm->config) 246 fn = pcm->config->compat_filter_fn; 247 248 return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data); 249 } 250 251 static bool dmaengine_pcm_can_report_residue(struct device *dev, 252 struct dma_chan *chan) 253 { 254 struct dma_slave_caps dma_caps; 255 int ret; 256 257 ret = dma_get_slave_caps(chan, &dma_caps); 258 if (ret != 0) { 259 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n", 260 ret); 261 return false; 262 } 263 264 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) 265 return false; 266 267 return true; 268 } 269 270 static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd) 271 { 272 struct snd_soc_component *component = 273 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 274 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 275 const struct snd_dmaengine_pcm_config *config = pcm->config; 276 struct device *dev = component->dev; 277 struct snd_dmaengine_dai_dma_data *dma_data; 278 struct snd_pcm_substream *substream; 279 size_t prealloc_buffer_size; 280 size_t max_buffer_size; 281 unsigned int i; 282 int ret; 283 284 if (config && config->prealloc_buffer_size) { 285 prealloc_buffer_size = config->prealloc_buffer_size; 286 max_buffer_size = config->pcm_hardware->buffer_bytes_max; 287 } else { 288 prealloc_buffer_size = 512 * 1024; 289 max_buffer_size = SIZE_MAX; 290 } 291 292 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { 293 substream = rtd->pcm->streams[i].substream; 294 if (!substream) 295 continue; 296 297 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 298 299 if (!pcm->chan[i] && 300 (pcm->flags & SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) 301 pcm->chan[i] = dma_request_slave_channel(dev, 302 dma_data->chan_name); 303 304 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) { 305 pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd, 306 substream); 307 } 308 309 if (!pcm->chan[i]) { 310 dev_err(component->dev, 311 "Missing dma channel for stream: %d\n", i); 312 return -EINVAL; 313 } 314 315 ret = snd_pcm_lib_preallocate_pages(substream, 316 SNDRV_DMA_TYPE_DEV_IRAM, 317 dmaengine_dma_dev(pcm, substream), 318 prealloc_buffer_size, 319 max_buffer_size); 320 if (ret) 321 return ret; 322 323 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i])) 324 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE; 325 } 326 327 return 0; 328 } 329 330 static snd_pcm_uframes_t dmaengine_pcm_pointer( 331 struct snd_pcm_substream *substream) 332 { 333 struct snd_soc_pcm_runtime *rtd = substream->private_data; 334 struct snd_soc_component *component = 335 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 336 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 337 338 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 339 return snd_dmaengine_pcm_pointer_no_residue(substream); 340 else 341 return snd_dmaengine_pcm_pointer(substream); 342 } 343 344 static int dmaengine_copy_user(struct snd_pcm_substream *substream, 345 int channel, unsigned long hwoff, 346 void *buf, unsigned long bytes) 347 { 348 struct snd_soc_pcm_runtime *rtd = substream->private_data; 349 struct snd_soc_component *component = 350 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 351 struct snd_pcm_runtime *runtime = substream->runtime; 352 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 353 int (*process)(struct snd_pcm_substream *substream, 354 int channel, unsigned long hwoff, 355 void *buf, unsigned long bytes) = pcm->config->process; 356 bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; 357 void *dma_ptr = runtime->dma_area + hwoff + 358 channel * (runtime->dma_bytes / runtime->channels); 359 int ret; 360 361 if (is_playback) 362 if (copy_from_user(dma_ptr, (void __user *)buf, bytes)) 363 return -EFAULT; 364 365 if (process) { 366 ret = process(substream, channel, hwoff, 367 (void __user *)buf, bytes); 368 if (ret < 0) 369 return ret; 370 } 371 372 if (!is_playback) 373 if (copy_to_user((void __user *)buf, dma_ptr, bytes)) 374 return -EFAULT; 375 376 return 0; 377 } 378 379 static const struct snd_pcm_ops dmaengine_pcm_ops = { 380 .open = dmaengine_pcm_open, 381 .close = snd_dmaengine_pcm_close, 382 .ioctl = snd_pcm_lib_ioctl, 383 .hw_params = dmaengine_pcm_hw_params, 384 .hw_free = snd_pcm_lib_free_pages, 385 .trigger = snd_dmaengine_pcm_trigger, 386 .pointer = dmaengine_pcm_pointer, 387 }; 388 389 static const struct snd_pcm_ops dmaengine_pcm_process_ops = { 390 .open = dmaengine_pcm_open, 391 .close = snd_dmaengine_pcm_close, 392 .ioctl = snd_pcm_lib_ioctl, 393 .hw_params = dmaengine_pcm_hw_params, 394 .hw_free = snd_pcm_lib_free_pages, 395 .trigger = snd_dmaengine_pcm_trigger, 396 .pointer = dmaengine_pcm_pointer, 397 .copy_user = dmaengine_copy_user, 398 }; 399 400 static const struct snd_soc_component_driver dmaengine_pcm_component = { 401 .name = SND_DMAENGINE_PCM_DRV_NAME, 402 .probe_order = SND_SOC_COMP_ORDER_LATE, 403 .ops = &dmaengine_pcm_ops, 404 .pcm_new = dmaengine_pcm_new, 405 }; 406 407 static const struct snd_soc_component_driver dmaengine_pcm_component_process = { 408 .name = SND_DMAENGINE_PCM_DRV_NAME, 409 .probe_order = SND_SOC_COMP_ORDER_LATE, 410 .ops = &dmaengine_pcm_process_ops, 411 .pcm_new = dmaengine_pcm_new, 412 }; 413 414 static const char * const dmaengine_pcm_dma_channel_names[] = { 415 [SNDRV_PCM_STREAM_PLAYBACK] = "tx", 416 [SNDRV_PCM_STREAM_CAPTURE] = "rx", 417 }; 418 419 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, 420 struct device *dev, const struct snd_dmaengine_pcm_config *config) 421 { 422 unsigned int i; 423 const char *name; 424 struct dma_chan *chan; 425 426 if ((pcm->flags & (SND_DMAENGINE_PCM_FLAG_NO_DT | 427 SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) || 428 !dev->of_node) 429 return 0; 430 431 if (config && config->dma_dev) { 432 /* 433 * If this warning is seen, it probably means that your Linux 434 * device structure does not match your HW device structure. 435 * It would be best to refactor the Linux device structure to 436 * correctly match the HW structure. 437 */ 438 dev_warn(dev, "DMA channels sourced from device %s", 439 dev_name(config->dma_dev)); 440 dev = config->dma_dev; 441 } 442 443 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 444 i++) { 445 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 446 name = "rx-tx"; 447 else 448 name = dmaengine_pcm_dma_channel_names[i]; 449 if (config && config->chan_names[i]) 450 name = config->chan_names[i]; 451 chan = dma_request_slave_channel_reason(dev, name); 452 if (IS_ERR(chan)) { 453 if (PTR_ERR(chan) == -EPROBE_DEFER) 454 return -EPROBE_DEFER; 455 pcm->chan[i] = NULL; 456 } else { 457 pcm->chan[i] = chan; 458 } 459 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 460 break; 461 } 462 463 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 464 pcm->chan[1] = pcm->chan[0]; 465 466 return 0; 467 } 468 469 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) 470 { 471 unsigned int i; 472 473 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 474 i++) { 475 if (!pcm->chan[i]) 476 continue; 477 dma_release_channel(pcm->chan[i]); 478 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 479 break; 480 } 481 } 482 483 /** 484 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device 485 * @dev: The parent device for the PCM device 486 * @config: Platform specific PCM configuration 487 * @flags: Platform specific quirks 488 */ 489 int snd_dmaengine_pcm_register(struct device *dev, 490 const struct snd_dmaengine_pcm_config *config, unsigned int flags) 491 { 492 struct dmaengine_pcm *pcm; 493 int ret; 494 495 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); 496 if (!pcm) 497 return -ENOMEM; 498 499 #ifdef CONFIG_DEBUG_FS 500 pcm->component.debugfs_prefix = "dma"; 501 #endif 502 pcm->config = config; 503 pcm->flags = flags; 504 505 ret = dmaengine_pcm_request_chan_of(pcm, dev, config); 506 if (ret) 507 goto err_free_dma; 508 509 if (config && config->process) 510 ret = snd_soc_add_component(dev, &pcm->component, 511 &dmaengine_pcm_component_process, 512 NULL, 0); 513 else 514 ret = snd_soc_add_component(dev, &pcm->component, 515 &dmaengine_pcm_component, NULL, 0); 516 if (ret) 517 goto err_free_dma; 518 519 return 0; 520 521 err_free_dma: 522 dmaengine_pcm_release_chan(pcm); 523 kfree(pcm); 524 return ret; 525 } 526 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); 527 528 /** 529 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device 530 * @dev: Parent device the PCM was register with 531 * 532 * Removes a dmaengine based PCM device previously registered with 533 * snd_dmaengine_pcm_register. 534 */ 535 void snd_dmaengine_pcm_unregister(struct device *dev) 536 { 537 struct snd_soc_component *component; 538 struct dmaengine_pcm *pcm; 539 540 component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME); 541 if (!component) 542 return; 543 544 pcm = soc_component_to_pcm(component); 545 546 snd_soc_unregister_component(dev); 547 dmaengine_pcm_release_chan(pcm); 548 kfree(pcm); 549 } 550 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); 551 552 MODULE_LICENSE("GPL"); 553