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_soc_component *component, 79 struct snd_pcm_substream *substream, 80 struct snd_pcm_hw_params *params) 81 { 82 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 83 struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream); 84 int (*prepare_slave_config)(struct snd_pcm_substream *substream, 85 struct snd_pcm_hw_params *params, 86 struct dma_slave_config *slave_config); 87 struct dma_slave_config slave_config; 88 int ret; 89 90 memset(&slave_config, 0, sizeof(slave_config)); 91 92 if (!pcm->config) 93 prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config; 94 else 95 prepare_slave_config = pcm->config->prepare_slave_config; 96 97 if (prepare_slave_config) { 98 ret = prepare_slave_config(substream, params, &slave_config); 99 if (ret) 100 return ret; 101 102 ret = dmaengine_slave_config(chan, &slave_config); 103 if (ret) 104 return ret; 105 } 106 107 return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params)); 108 } 109 110 static int 111 dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component, 112 struct snd_pcm_substream *substream) 113 { 114 struct snd_soc_pcm_runtime *rtd = substream->private_data; 115 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 116 struct device *dma_dev = dmaengine_dma_dev(pcm, substream); 117 struct dma_chan *chan = pcm->chan[substream->stream]; 118 struct snd_dmaengine_dai_dma_data *dma_data; 119 struct snd_pcm_hardware hw; 120 int ret; 121 122 if (pcm->config && pcm->config->pcm_hardware) 123 return snd_soc_set_runtime_hwparams(substream, 124 pcm->config->pcm_hardware); 125 126 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 127 128 memset(&hw, 0, sizeof(hw)); 129 hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | 130 SNDRV_PCM_INFO_INTERLEAVED; 131 hw.periods_min = 2; 132 hw.periods_max = UINT_MAX; 133 hw.period_bytes_min = 256; 134 hw.period_bytes_max = dma_get_max_seg_size(dma_dev); 135 hw.buffer_bytes_max = SIZE_MAX; 136 hw.fifo_size = dma_data->fifo_size; 137 138 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 139 hw.info |= SNDRV_PCM_INFO_BATCH; 140 141 ret = snd_dmaengine_pcm_refine_runtime_hwparams(substream, 142 dma_data, 143 &hw, 144 chan); 145 if (ret) 146 return ret; 147 148 return snd_soc_set_runtime_hwparams(substream, &hw); 149 } 150 151 static int dmaengine_pcm_open(struct snd_soc_component *component, 152 struct snd_pcm_substream *substream) 153 { 154 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 155 struct dma_chan *chan = pcm->chan[substream->stream]; 156 int ret; 157 158 ret = dmaengine_pcm_set_runtime_hwparams(component, substream); 159 if (ret) 160 return ret; 161 162 return snd_dmaengine_pcm_open(substream, chan); 163 } 164 165 static int dmaengine_pcm_close(struct snd_soc_component *component, 166 struct snd_pcm_substream *substream) 167 { 168 return snd_dmaengine_pcm_close(substream); 169 } 170 171 static int dmaengine_pcm_hw_free(struct snd_soc_component *component, 172 struct snd_pcm_substream *substream) 173 { 174 return snd_pcm_lib_free_pages(substream); 175 } 176 177 static int dmaengine_pcm_trigger(struct snd_soc_component *component, 178 struct snd_pcm_substream *substream, int cmd) 179 { 180 return snd_dmaengine_pcm_trigger(substream, cmd); 181 } 182 183 static struct dma_chan *dmaengine_pcm_compat_request_channel( 184 struct snd_soc_component *component, 185 struct snd_soc_pcm_runtime *rtd, 186 struct snd_pcm_substream *substream) 187 { 188 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 189 struct snd_dmaengine_dai_dma_data *dma_data; 190 dma_filter_fn fn = NULL; 191 192 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 193 194 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0]) 195 return pcm->chan[0]; 196 197 if (pcm->config && pcm->config->compat_request_channel) 198 return pcm->config->compat_request_channel(rtd, substream); 199 200 if (pcm->config) 201 fn = pcm->config->compat_filter_fn; 202 203 return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data); 204 } 205 206 static bool dmaengine_pcm_can_report_residue(struct device *dev, 207 struct dma_chan *chan) 208 { 209 struct dma_slave_caps dma_caps; 210 int ret; 211 212 ret = dma_get_slave_caps(chan, &dma_caps); 213 if (ret != 0) { 214 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n", 215 ret); 216 return false; 217 } 218 219 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) 220 return false; 221 222 return true; 223 } 224 225 static int dmaengine_pcm_new(struct snd_soc_component *component, 226 struct snd_soc_pcm_runtime *rtd) 227 { 228 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 229 const struct snd_dmaengine_pcm_config *config = pcm->config; 230 struct device *dev = component->dev; 231 struct snd_pcm_substream *substream; 232 size_t prealloc_buffer_size; 233 size_t max_buffer_size; 234 unsigned int i; 235 236 if (config && config->prealloc_buffer_size) { 237 prealloc_buffer_size = config->prealloc_buffer_size; 238 max_buffer_size = config->pcm_hardware->buffer_bytes_max; 239 } else { 240 prealloc_buffer_size = 512 * 1024; 241 max_buffer_size = SIZE_MAX; 242 } 243 244 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { 245 substream = rtd->pcm->streams[i].substream; 246 if (!substream) 247 continue; 248 249 if (!pcm->chan[i] && config && config->chan_names[i]) 250 pcm->chan[i] = dma_request_slave_channel(dev, 251 config->chan_names[i]); 252 253 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) { 254 pcm->chan[i] = dmaengine_pcm_compat_request_channel( 255 component, rtd, substream); 256 } 257 258 if (!pcm->chan[i]) { 259 dev_err(component->dev, 260 "Missing dma channel for stream: %d\n", i); 261 return -EINVAL; 262 } 263 264 snd_pcm_lib_preallocate_pages(substream, 265 SNDRV_DMA_TYPE_DEV_IRAM, 266 dmaengine_dma_dev(pcm, substream), 267 prealloc_buffer_size, 268 max_buffer_size); 269 270 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i])) 271 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE; 272 273 if (rtd->pcm->streams[i].pcm->name[0] == '\0') { 274 strscpy_pad(rtd->pcm->streams[i].pcm->name, 275 rtd->pcm->streams[i].pcm->id, 276 sizeof(rtd->pcm->streams[i].pcm->name)); 277 } 278 } 279 280 return 0; 281 } 282 283 static snd_pcm_uframes_t dmaengine_pcm_pointer( 284 struct snd_soc_component *component, 285 struct snd_pcm_substream *substream) 286 { 287 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 288 289 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 290 return snd_dmaengine_pcm_pointer_no_residue(substream); 291 else 292 return snd_dmaengine_pcm_pointer(substream); 293 } 294 295 static int dmaengine_copy_user(struct snd_soc_component *component, 296 struct snd_pcm_substream *substream, 297 int channel, unsigned long hwoff, 298 void __user *buf, unsigned long bytes) 299 { 300 struct snd_pcm_runtime *runtime = substream->runtime; 301 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 302 int (*process)(struct snd_pcm_substream *substream, 303 int channel, unsigned long hwoff, 304 void *buf, unsigned long bytes) = pcm->config->process; 305 bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; 306 void *dma_ptr = runtime->dma_area + hwoff + 307 channel * (runtime->dma_bytes / runtime->channels); 308 int ret; 309 310 if (is_playback) 311 if (copy_from_user(dma_ptr, buf, bytes)) 312 return -EFAULT; 313 314 if (process) { 315 ret = process(substream, channel, hwoff, (__force void *)buf, bytes); 316 if (ret < 0) 317 return ret; 318 } 319 320 if (!is_playback) 321 if (copy_to_user(buf, dma_ptr, bytes)) 322 return -EFAULT; 323 324 return 0; 325 } 326 327 static const struct snd_soc_component_driver dmaengine_pcm_component = { 328 .name = SND_DMAENGINE_PCM_DRV_NAME, 329 .probe_order = SND_SOC_COMP_ORDER_LATE, 330 .open = dmaengine_pcm_open, 331 .close = dmaengine_pcm_close, 332 .ioctl = snd_soc_pcm_lib_ioctl, 333 .hw_params = dmaengine_pcm_hw_params, 334 .hw_free = dmaengine_pcm_hw_free, 335 .trigger = dmaengine_pcm_trigger, 336 .pointer = dmaengine_pcm_pointer, 337 .pcm_construct = dmaengine_pcm_new, 338 }; 339 340 static const struct snd_soc_component_driver dmaengine_pcm_component_process = { 341 .name = SND_DMAENGINE_PCM_DRV_NAME, 342 .probe_order = SND_SOC_COMP_ORDER_LATE, 343 .open = dmaengine_pcm_open, 344 .close = dmaengine_pcm_close, 345 .ioctl = snd_soc_pcm_lib_ioctl, 346 .hw_params = dmaengine_pcm_hw_params, 347 .hw_free = dmaengine_pcm_hw_free, 348 .trigger = dmaengine_pcm_trigger, 349 .pointer = dmaengine_pcm_pointer, 350 .copy_user = dmaengine_copy_user, 351 .pcm_construct = dmaengine_pcm_new, 352 }; 353 354 static const char * const dmaengine_pcm_dma_channel_names[] = { 355 [SNDRV_PCM_STREAM_PLAYBACK] = "tx", 356 [SNDRV_PCM_STREAM_CAPTURE] = "rx", 357 }; 358 359 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, 360 struct device *dev, const struct snd_dmaengine_pcm_config *config) 361 { 362 unsigned int i; 363 const char *name; 364 struct dma_chan *chan; 365 366 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node && 367 !(config && config->dma_dev && config->dma_dev->of_node))) 368 return 0; 369 370 if (config && config->dma_dev) { 371 /* 372 * If this warning is seen, it probably means that your Linux 373 * device structure does not match your HW device structure. 374 * It would be best to refactor the Linux device structure to 375 * correctly match the HW structure. 376 */ 377 dev_warn(dev, "DMA channels sourced from device %s", 378 dev_name(config->dma_dev)); 379 dev = config->dma_dev; 380 } 381 382 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 383 i++) { 384 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 385 name = "rx-tx"; 386 else 387 name = dmaengine_pcm_dma_channel_names[i]; 388 if (config && config->chan_names[i]) 389 name = config->chan_names[i]; 390 chan = dma_request_chan(dev, name); 391 if (IS_ERR(chan)) { 392 if (PTR_ERR(chan) == -EPROBE_DEFER) 393 return -EPROBE_DEFER; 394 pcm->chan[i] = NULL; 395 } else { 396 pcm->chan[i] = chan; 397 } 398 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 399 break; 400 } 401 402 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 403 pcm->chan[1] = pcm->chan[0]; 404 405 return 0; 406 } 407 408 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) 409 { 410 unsigned int i; 411 412 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 413 i++) { 414 if (!pcm->chan[i]) 415 continue; 416 dma_release_channel(pcm->chan[i]); 417 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 418 break; 419 } 420 } 421 422 /** 423 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device 424 * @dev: The parent device for the PCM device 425 * @config: Platform specific PCM configuration 426 * @flags: Platform specific quirks 427 */ 428 int snd_dmaengine_pcm_register(struct device *dev, 429 const struct snd_dmaengine_pcm_config *config, unsigned int flags) 430 { 431 struct dmaengine_pcm *pcm; 432 int ret; 433 434 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); 435 if (!pcm) 436 return -ENOMEM; 437 438 #ifdef CONFIG_DEBUG_FS 439 pcm->component.debugfs_prefix = "dma"; 440 #endif 441 pcm->config = config; 442 pcm->flags = flags; 443 444 ret = dmaengine_pcm_request_chan_of(pcm, dev, config); 445 if (ret) 446 goto err_free_dma; 447 448 if (config && config->process) 449 ret = snd_soc_add_component(dev, &pcm->component, 450 &dmaengine_pcm_component_process, 451 NULL, 0); 452 else 453 ret = snd_soc_add_component(dev, &pcm->component, 454 &dmaengine_pcm_component, NULL, 0); 455 if (ret) 456 goto err_free_dma; 457 458 return 0; 459 460 err_free_dma: 461 dmaengine_pcm_release_chan(pcm); 462 kfree(pcm); 463 return ret; 464 } 465 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); 466 467 /** 468 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device 469 * @dev: Parent device the PCM was register with 470 * 471 * Removes a dmaengine based PCM device previously registered with 472 * snd_dmaengine_pcm_register. 473 */ 474 void snd_dmaengine_pcm_unregister(struct device *dev) 475 { 476 struct snd_soc_component *component; 477 struct dmaengine_pcm *pcm; 478 479 component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME); 480 if (!component) 481 return; 482 483 pcm = soc_component_to_pcm(component); 484 485 snd_soc_unregister_component(dev); 486 dmaengine_pcm_release_chan(pcm); 487 kfree(pcm); 488 } 489 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); 490 491 MODULE_LICENSE("GPL"); 492