1 // SPDX-License-Identifier: GPL-2.0+ 2 // 3 // Copyright (C) 2013, Analog Devices Inc. 4 // Author: Lars-Peter Clausen <lars@metafoo.de> 5 6 #include <linux/module.h> 7 #include <linux/init.h> 8 #include <linux/dmaengine.h> 9 #include <linux/slab.h> 10 #include <sound/pcm.h> 11 #include <sound/pcm_params.h> 12 #include <sound/soc.h> 13 #include <linux/dma-mapping.h> 14 #include <linux/of.h> 15 16 #include <sound/dmaengine_pcm.h> 17 18 /* 19 * The platforms dmaengine driver does not support reporting the amount of 20 * bytes that are still left to transfer. 21 */ 22 #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31) 23 24 struct dmaengine_pcm { 25 struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1]; 26 const struct snd_dmaengine_pcm_config *config; 27 struct snd_soc_component component; 28 unsigned int flags; 29 }; 30 31 static struct dmaengine_pcm *soc_component_to_pcm(struct snd_soc_component *p) 32 { 33 return container_of(p, struct dmaengine_pcm, component); 34 } 35 36 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm, 37 struct snd_pcm_substream *substream) 38 { 39 if (!pcm->chan[substream->stream]) 40 return NULL; 41 42 return pcm->chan[substream->stream]->device->dev; 43 } 44 45 /** 46 * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback 47 * @substream: PCM substream 48 * @params: hw_params 49 * @slave_config: DMA slave config to prepare 50 * 51 * This function can be used as a generic prepare_slave_config callback for 52 * platforms which make use of the snd_dmaengine_dai_dma_data struct for their 53 * DAI DMA data. Internally the function will first call 54 * snd_hwparams_to_dma_slave_config to fill in the slave config based on the 55 * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the 56 * remaining fields based on the DAI DMA data. 57 */ 58 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream, 59 struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config) 60 { 61 struct snd_soc_pcm_runtime *rtd = substream->private_data; 62 struct snd_dmaengine_dai_dma_data *dma_data; 63 int ret; 64 65 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 66 67 ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config); 68 if (ret) 69 return ret; 70 71 snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data, 72 slave_config); 73 74 return 0; 75 } 76 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config); 77 78 static int dmaengine_pcm_hw_params(struct snd_pcm_substream *substream, 79 struct snd_pcm_hw_params *params) 80 { 81 struct snd_soc_pcm_runtime *rtd = substream->private_data; 82 struct snd_soc_component *component = 83 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 84 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 85 struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream); 86 int (*prepare_slave_config)(struct snd_pcm_substream *substream, 87 struct snd_pcm_hw_params *params, 88 struct dma_slave_config *slave_config); 89 struct dma_slave_config slave_config; 90 int ret; 91 92 memset(&slave_config, 0, sizeof(slave_config)); 93 94 if (!pcm->config) 95 prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config; 96 else 97 prepare_slave_config = pcm->config->prepare_slave_config; 98 99 if (prepare_slave_config) { 100 ret = prepare_slave_config(substream, params, &slave_config); 101 if (ret) 102 return ret; 103 104 ret = dmaengine_slave_config(chan, &slave_config); 105 if (ret) 106 return ret; 107 } 108 109 return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params)); 110 } 111 112 static int dmaengine_pcm_set_runtime_hwparams(struct snd_pcm_substream *substream) 113 { 114 struct snd_soc_pcm_runtime *rtd = substream->private_data; 115 struct snd_soc_component *component = 116 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 117 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 118 struct device *dma_dev = dmaengine_dma_dev(pcm, substream); 119 struct dma_chan *chan = pcm->chan[substream->stream]; 120 struct snd_dmaengine_dai_dma_data *dma_data; 121 struct dma_slave_caps dma_caps; 122 struct snd_pcm_hardware hw; 123 u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | 124 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | 125 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); 126 snd_pcm_format_t i; 127 int ret; 128 129 if (pcm->config && pcm->config->pcm_hardware) 130 return snd_soc_set_runtime_hwparams(substream, 131 pcm->config->pcm_hardware); 132 133 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 134 135 memset(&hw, 0, sizeof(hw)); 136 hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | 137 SNDRV_PCM_INFO_INTERLEAVED; 138 hw.periods_min = 2; 139 hw.periods_max = UINT_MAX; 140 hw.period_bytes_min = 256; 141 hw.period_bytes_max = dma_get_max_seg_size(dma_dev); 142 hw.buffer_bytes_max = SIZE_MAX; 143 hw.fifo_size = dma_data->fifo_size; 144 145 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 146 hw.info |= SNDRV_PCM_INFO_BATCH; 147 148 ret = dma_get_slave_caps(chan, &dma_caps); 149 if (ret == 0) { 150 if (dma_caps.cmd_pause && dma_caps.cmd_resume) 151 hw.info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME; 152 if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT) 153 hw.info |= SNDRV_PCM_INFO_BATCH; 154 155 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) 156 addr_widths = dma_caps.dst_addr_widths; 157 else 158 addr_widths = dma_caps.src_addr_widths; 159 } 160 161 /* 162 * If SND_DMAENGINE_PCM_DAI_FLAG_PACK is set keep 163 * hw.formats set to 0, meaning no restrictions are in place. 164 * In this case it's the responsibility of the DAI driver to 165 * provide the supported format information. 166 */ 167 if (!(dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)) 168 /* 169 * Prepare formats mask for valid/allowed sample types. If the 170 * dma does not have support for the given physical word size, 171 * it needs to be masked out so user space can not use the 172 * format which produces corrupted audio. 173 * In case the dma driver does not implement the slave_caps the 174 * default assumption is that it supports 1, 2 and 4 bytes 175 * widths. 176 */ 177 for (i = SNDRV_PCM_FORMAT_FIRST; i <= SNDRV_PCM_FORMAT_LAST; i++) { 178 int bits = snd_pcm_format_physical_width(i); 179 180 /* 181 * Enable only samples with DMA supported physical 182 * widths 183 */ 184 switch (bits) { 185 case 8: 186 case 16: 187 case 24: 188 case 32: 189 case 64: 190 if (addr_widths & (1 << (bits / 8))) 191 hw.formats |= pcm_format_to_bits(i); 192 break; 193 default: 194 /* Unsupported types */ 195 break; 196 } 197 } 198 199 return snd_soc_set_runtime_hwparams(substream, &hw); 200 } 201 202 static int dmaengine_pcm_open(struct snd_pcm_substream *substream) 203 { 204 struct snd_soc_pcm_runtime *rtd = substream->private_data; 205 struct snd_soc_component *component = 206 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 207 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 208 struct dma_chan *chan = pcm->chan[substream->stream]; 209 int ret; 210 211 ret = dmaengine_pcm_set_runtime_hwparams(substream); 212 if (ret) 213 return ret; 214 215 return snd_dmaengine_pcm_open(substream, chan); 216 } 217 218 static struct dma_chan *dmaengine_pcm_compat_request_channel( 219 struct snd_soc_pcm_runtime *rtd, 220 struct snd_pcm_substream *substream) 221 { 222 struct snd_soc_component *component = 223 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 224 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 225 struct snd_dmaengine_dai_dma_data *dma_data; 226 dma_filter_fn fn = NULL; 227 228 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 229 230 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0]) 231 return pcm->chan[0]; 232 233 if (pcm->config && pcm->config->compat_request_channel) 234 return pcm->config->compat_request_channel(rtd, substream); 235 236 if (pcm->config) 237 fn = pcm->config->compat_filter_fn; 238 239 return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data); 240 } 241 242 static bool dmaengine_pcm_can_report_residue(struct device *dev, 243 struct dma_chan *chan) 244 { 245 struct dma_slave_caps dma_caps; 246 int ret; 247 248 ret = dma_get_slave_caps(chan, &dma_caps); 249 if (ret != 0) { 250 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n", 251 ret); 252 return false; 253 } 254 255 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) 256 return false; 257 258 return true; 259 } 260 261 static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd) 262 { 263 struct snd_soc_component *component = 264 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 265 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 266 const struct snd_dmaengine_pcm_config *config = pcm->config; 267 struct device *dev = component->dev; 268 struct snd_dmaengine_dai_dma_data *dma_data; 269 struct snd_pcm_substream *substream; 270 size_t prealloc_buffer_size; 271 size_t max_buffer_size; 272 unsigned int i; 273 int ret; 274 275 if (config && config->prealloc_buffer_size) { 276 prealloc_buffer_size = config->prealloc_buffer_size; 277 max_buffer_size = config->pcm_hardware->buffer_bytes_max; 278 } else { 279 prealloc_buffer_size = 512 * 1024; 280 max_buffer_size = SIZE_MAX; 281 } 282 283 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { 284 substream = rtd->pcm->streams[i].substream; 285 if (!substream) 286 continue; 287 288 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 289 290 if (!pcm->chan[i] && 291 (pcm->flags & SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) 292 pcm->chan[i] = dma_request_slave_channel(dev, 293 dma_data->chan_name); 294 295 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) { 296 pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd, 297 substream); 298 } 299 300 if (!pcm->chan[i]) { 301 dev_err(component->dev, 302 "Missing dma channel for stream: %d\n", i); 303 return -EINVAL; 304 } 305 306 ret = snd_pcm_lib_preallocate_pages(substream, 307 SNDRV_DMA_TYPE_DEV_IRAM, 308 dmaengine_dma_dev(pcm, substream), 309 prealloc_buffer_size, 310 max_buffer_size); 311 if (ret) 312 return ret; 313 314 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i])) 315 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE; 316 } 317 318 return 0; 319 } 320 321 static snd_pcm_uframes_t dmaengine_pcm_pointer( 322 struct snd_pcm_substream *substream) 323 { 324 struct snd_soc_pcm_runtime *rtd = substream->private_data; 325 struct snd_soc_component *component = 326 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 327 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 328 329 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 330 return snd_dmaengine_pcm_pointer_no_residue(substream); 331 else 332 return snd_dmaengine_pcm_pointer(substream); 333 } 334 335 static int dmaengine_copy_user(struct snd_pcm_substream *substream, 336 int channel, unsigned long hwoff, 337 void __user *buf, unsigned long bytes) 338 { 339 struct snd_soc_pcm_runtime *rtd = substream->private_data; 340 struct snd_soc_component *component = 341 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 342 struct snd_pcm_runtime *runtime = substream->runtime; 343 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 344 int (*process)(struct snd_pcm_substream *substream, 345 int channel, unsigned long hwoff, 346 void *buf, unsigned long bytes) = pcm->config->process; 347 bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; 348 void *dma_ptr = runtime->dma_area + hwoff + 349 channel * (runtime->dma_bytes / runtime->channels); 350 int ret; 351 352 if (is_playback) 353 if (copy_from_user(dma_ptr, buf, bytes)) 354 return -EFAULT; 355 356 if (process) { 357 ret = process(substream, channel, hwoff, (__force void *)buf, bytes); 358 if (ret < 0) 359 return ret; 360 } 361 362 if (!is_playback) 363 if (copy_to_user(buf, dma_ptr, bytes)) 364 return -EFAULT; 365 366 return 0; 367 } 368 369 static const struct snd_pcm_ops dmaengine_pcm_ops = { 370 .open = dmaengine_pcm_open, 371 .close = snd_dmaengine_pcm_close, 372 .ioctl = snd_pcm_lib_ioctl, 373 .hw_params = dmaengine_pcm_hw_params, 374 .hw_free = snd_pcm_lib_free_pages, 375 .trigger = snd_dmaengine_pcm_trigger, 376 .pointer = dmaengine_pcm_pointer, 377 }; 378 379 static const struct snd_pcm_ops dmaengine_pcm_process_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 .copy_user = dmaengine_copy_user, 388 }; 389 390 static const struct snd_soc_component_driver dmaengine_pcm_component = { 391 .name = SND_DMAENGINE_PCM_DRV_NAME, 392 .probe_order = SND_SOC_COMP_ORDER_LATE, 393 .ops = &dmaengine_pcm_ops, 394 .pcm_new = dmaengine_pcm_new, 395 }; 396 397 static const struct snd_soc_component_driver dmaengine_pcm_component_process = { 398 .name = SND_DMAENGINE_PCM_DRV_NAME, 399 .probe_order = SND_SOC_COMP_ORDER_LATE, 400 .ops = &dmaengine_pcm_process_ops, 401 .pcm_new = dmaengine_pcm_new, 402 }; 403 404 static const char * const dmaengine_pcm_dma_channel_names[] = { 405 [SNDRV_PCM_STREAM_PLAYBACK] = "tx", 406 [SNDRV_PCM_STREAM_CAPTURE] = "rx", 407 }; 408 409 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, 410 struct device *dev, const struct snd_dmaengine_pcm_config *config) 411 { 412 unsigned int i; 413 const char *name; 414 struct dma_chan *chan; 415 416 if ((pcm->flags & (SND_DMAENGINE_PCM_FLAG_NO_DT | 417 SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) || 418 !dev->of_node) 419 return 0; 420 421 if (config && config->dma_dev) { 422 /* 423 * If this warning is seen, it probably means that your Linux 424 * device structure does not match your HW device structure. 425 * It would be best to refactor the Linux device structure to 426 * correctly match the HW structure. 427 */ 428 dev_warn(dev, "DMA channels sourced from device %s", 429 dev_name(config->dma_dev)); 430 dev = config->dma_dev; 431 } 432 433 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 434 i++) { 435 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 436 name = "rx-tx"; 437 else 438 name = dmaengine_pcm_dma_channel_names[i]; 439 if (config && config->chan_names[i]) 440 name = config->chan_names[i]; 441 chan = dma_request_slave_channel_reason(dev, name); 442 if (IS_ERR(chan)) { 443 if (PTR_ERR(chan) == -EPROBE_DEFER) 444 return -EPROBE_DEFER; 445 pcm->chan[i] = NULL; 446 } else { 447 pcm->chan[i] = chan; 448 } 449 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 450 break; 451 } 452 453 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 454 pcm->chan[1] = pcm->chan[0]; 455 456 return 0; 457 } 458 459 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) 460 { 461 unsigned int i; 462 463 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 464 i++) { 465 if (!pcm->chan[i]) 466 continue; 467 dma_release_channel(pcm->chan[i]); 468 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 469 break; 470 } 471 } 472 473 /** 474 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device 475 * @dev: The parent device for the PCM device 476 * @config: Platform specific PCM configuration 477 * @flags: Platform specific quirks 478 */ 479 int snd_dmaengine_pcm_register(struct device *dev, 480 const struct snd_dmaengine_pcm_config *config, unsigned int flags) 481 { 482 struct dmaengine_pcm *pcm; 483 int ret; 484 485 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); 486 if (!pcm) 487 return -ENOMEM; 488 489 #ifdef CONFIG_DEBUG_FS 490 pcm->component.debugfs_prefix = "dma"; 491 #endif 492 pcm->config = config; 493 pcm->flags = flags; 494 495 ret = dmaengine_pcm_request_chan_of(pcm, dev, config); 496 if (ret) 497 goto err_free_dma; 498 499 if (config && config->process) 500 ret = snd_soc_add_component(dev, &pcm->component, 501 &dmaengine_pcm_component_process, 502 NULL, 0); 503 else 504 ret = snd_soc_add_component(dev, &pcm->component, 505 &dmaengine_pcm_component, NULL, 0); 506 if (ret) 507 goto err_free_dma; 508 509 return 0; 510 511 err_free_dma: 512 dmaengine_pcm_release_chan(pcm); 513 kfree(pcm); 514 return ret; 515 } 516 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); 517 518 /** 519 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device 520 * @dev: Parent device the PCM was register with 521 * 522 * Removes a dmaengine based PCM device previously registered with 523 * snd_dmaengine_pcm_register. 524 */ 525 void snd_dmaengine_pcm_unregister(struct device *dev) 526 { 527 struct snd_soc_component *component; 528 struct dmaengine_pcm *pcm; 529 530 component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME); 531 if (!component) 532 return; 533 534 pcm = soc_component_to_pcm(component); 535 536 snd_soc_unregister_component(dev); 537 dmaengine_pcm_release_chan(pcm); 538 kfree(pcm); 539 } 540 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); 541 542 MODULE_LICENSE("GPL"); 543