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_pcm_substream *substream; 269 size_t prealloc_buffer_size; 270 size_t max_buffer_size; 271 unsigned int i; 272 273 if (config && config->prealloc_buffer_size) { 274 prealloc_buffer_size = config->prealloc_buffer_size; 275 max_buffer_size = config->pcm_hardware->buffer_bytes_max; 276 } else { 277 prealloc_buffer_size = 512 * 1024; 278 max_buffer_size = SIZE_MAX; 279 } 280 281 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { 282 substream = rtd->pcm->streams[i].substream; 283 if (!substream) 284 continue; 285 286 if (!pcm->chan[i] && config && config->chan_names[i]) 287 pcm->chan[i] = dma_request_slave_channel(dev, 288 config->chan_names[i]); 289 290 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) { 291 pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd, 292 substream); 293 } 294 295 if (!pcm->chan[i]) { 296 dev_err(component->dev, 297 "Missing dma channel for stream: %d\n", i); 298 return -EINVAL; 299 } 300 301 snd_pcm_lib_preallocate_pages(substream, 302 SNDRV_DMA_TYPE_DEV_IRAM, 303 dmaengine_dma_dev(pcm, substream), 304 prealloc_buffer_size, 305 max_buffer_size); 306 307 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i])) 308 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE; 309 310 if (rtd->pcm->streams[i].pcm->name[0] == '\0') { 311 strscpy_pad(rtd->pcm->streams[i].pcm->name, 312 rtd->pcm->streams[i].pcm->id, 313 sizeof(rtd->pcm->streams[i].pcm->name)); 314 } 315 } 316 317 return 0; 318 } 319 320 static snd_pcm_uframes_t dmaengine_pcm_pointer( 321 struct snd_pcm_substream *substream) 322 { 323 struct snd_soc_pcm_runtime *rtd = substream->private_data; 324 struct snd_soc_component *component = 325 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 326 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 327 328 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 329 return snd_dmaengine_pcm_pointer_no_residue(substream); 330 else 331 return snd_dmaengine_pcm_pointer(substream); 332 } 333 334 static int dmaengine_copy_user(struct snd_pcm_substream *substream, 335 int channel, unsigned long hwoff, 336 void __user *buf, unsigned long bytes) 337 { 338 struct snd_soc_pcm_runtime *rtd = substream->private_data; 339 struct snd_soc_component *component = 340 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); 341 struct snd_pcm_runtime *runtime = substream->runtime; 342 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 343 int (*process)(struct snd_pcm_substream *substream, 344 int channel, unsigned long hwoff, 345 void *buf, unsigned long bytes) = pcm->config->process; 346 bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; 347 void *dma_ptr = runtime->dma_area + hwoff + 348 channel * (runtime->dma_bytes / runtime->channels); 349 int ret; 350 351 if (is_playback) 352 if (copy_from_user(dma_ptr, buf, bytes)) 353 return -EFAULT; 354 355 if (process) { 356 ret = process(substream, channel, hwoff, (__force void *)buf, bytes); 357 if (ret < 0) 358 return ret; 359 } 360 361 if (!is_playback) 362 if (copy_to_user(buf, dma_ptr, bytes)) 363 return -EFAULT; 364 365 return 0; 366 } 367 368 static const struct snd_pcm_ops dmaengine_pcm_ops = { 369 .open = dmaengine_pcm_open, 370 .close = snd_dmaengine_pcm_close, 371 .ioctl = snd_pcm_lib_ioctl, 372 .hw_params = dmaengine_pcm_hw_params, 373 .hw_free = snd_pcm_lib_free_pages, 374 .trigger = snd_dmaengine_pcm_trigger, 375 .pointer = dmaengine_pcm_pointer, 376 }; 377 378 static const struct snd_pcm_ops dmaengine_pcm_process_ops = { 379 .open = dmaengine_pcm_open, 380 .close = snd_dmaengine_pcm_close, 381 .ioctl = snd_pcm_lib_ioctl, 382 .hw_params = dmaengine_pcm_hw_params, 383 .hw_free = snd_pcm_lib_free_pages, 384 .trigger = snd_dmaengine_pcm_trigger, 385 .pointer = dmaengine_pcm_pointer, 386 .copy_user = dmaengine_copy_user, 387 }; 388 389 static const struct snd_soc_component_driver dmaengine_pcm_component = { 390 .name = SND_DMAENGINE_PCM_DRV_NAME, 391 .probe_order = SND_SOC_COMP_ORDER_LATE, 392 .ops = &dmaengine_pcm_ops, 393 .pcm_new = dmaengine_pcm_new, 394 }; 395 396 static const struct snd_soc_component_driver dmaengine_pcm_component_process = { 397 .name = SND_DMAENGINE_PCM_DRV_NAME, 398 .probe_order = SND_SOC_COMP_ORDER_LATE, 399 .ops = &dmaengine_pcm_process_ops, 400 .pcm_new = dmaengine_pcm_new, 401 }; 402 403 static const char * const dmaengine_pcm_dma_channel_names[] = { 404 [SNDRV_PCM_STREAM_PLAYBACK] = "tx", 405 [SNDRV_PCM_STREAM_CAPTURE] = "rx", 406 }; 407 408 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, 409 struct device *dev, const struct snd_dmaengine_pcm_config *config) 410 { 411 unsigned int i; 412 const char *name; 413 struct dma_chan *chan; 414 415 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node && 416 !(config && config->dma_dev && config->dma_dev->of_node))) 417 return 0; 418 419 if (config && config->dma_dev) { 420 /* 421 * If this warning is seen, it probably means that your Linux 422 * device structure does not match your HW device structure. 423 * It would be best to refactor the Linux device structure to 424 * correctly match the HW structure. 425 */ 426 dev_warn(dev, "DMA channels sourced from device %s", 427 dev_name(config->dma_dev)); 428 dev = config->dma_dev; 429 } 430 431 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 432 i++) { 433 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 434 name = "rx-tx"; 435 else 436 name = dmaengine_pcm_dma_channel_names[i]; 437 if (config && config->chan_names[i]) 438 name = config->chan_names[i]; 439 chan = dma_request_slave_channel_reason(dev, name); 440 if (IS_ERR(chan)) { 441 if (PTR_ERR(chan) == -EPROBE_DEFER) 442 return -EPROBE_DEFER; 443 pcm->chan[i] = NULL; 444 } else { 445 pcm->chan[i] = chan; 446 } 447 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 448 break; 449 } 450 451 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 452 pcm->chan[1] = pcm->chan[0]; 453 454 return 0; 455 } 456 457 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) 458 { 459 unsigned int i; 460 461 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 462 i++) { 463 if (!pcm->chan[i]) 464 continue; 465 dma_release_channel(pcm->chan[i]); 466 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 467 break; 468 } 469 } 470 471 /** 472 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device 473 * @dev: The parent device for the PCM device 474 * @config: Platform specific PCM configuration 475 * @flags: Platform specific quirks 476 */ 477 int snd_dmaengine_pcm_register(struct device *dev, 478 const struct snd_dmaengine_pcm_config *config, unsigned int flags) 479 { 480 struct dmaengine_pcm *pcm; 481 int ret; 482 483 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); 484 if (!pcm) 485 return -ENOMEM; 486 487 #ifdef CONFIG_DEBUG_FS 488 pcm->component.debugfs_prefix = "dma"; 489 #endif 490 pcm->config = config; 491 pcm->flags = flags; 492 493 ret = dmaengine_pcm_request_chan_of(pcm, dev, config); 494 if (ret) 495 goto err_free_dma; 496 497 if (config && config->process) 498 ret = snd_soc_add_component(dev, &pcm->component, 499 &dmaengine_pcm_component_process, 500 NULL, 0); 501 else 502 ret = snd_soc_add_component(dev, &pcm->component, 503 &dmaengine_pcm_component, NULL, 0); 504 if (ret) 505 goto err_free_dma; 506 507 return 0; 508 509 err_free_dma: 510 dmaengine_pcm_release_chan(pcm); 511 kfree(pcm); 512 return ret; 513 } 514 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); 515 516 /** 517 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device 518 * @dev: Parent device the PCM was register with 519 * 520 * Removes a dmaengine based PCM device previously registered with 521 * snd_dmaengine_pcm_register. 522 */ 523 void snd_dmaengine_pcm_unregister(struct device *dev) 524 { 525 struct snd_soc_component *component; 526 struct dmaengine_pcm *pcm; 527 528 component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME); 529 if (!component) 530 return; 531 532 pcm = soc_component_to_pcm(component); 533 534 snd_soc_unregister_component(dev); 535 dmaengine_pcm_release_chan(pcm); 536 kfree(pcm); 537 } 538 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); 539 540 MODULE_LICENSE("GPL"); 541