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; 120 121 if (pcm->config && pcm->config->pcm_hardware) 122 return snd_soc_set_runtime_hwparams(substream, 123 pcm->config->pcm_hardware); 124 125 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 126 127 memset(&hw, 0, sizeof(hw)); 128 hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | 129 SNDRV_PCM_INFO_INTERLEAVED; 130 hw.periods_min = 2; 131 hw.periods_max = UINT_MAX; 132 hw.period_bytes_min = 256; 133 hw.period_bytes_max = dma_get_max_seg_size(dma_dev); 134 hw.buffer_bytes_max = SIZE_MAX; 135 hw.fifo_size = dma_data->fifo_size; 136 137 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 138 hw.info |= SNDRV_PCM_INFO_BATCH; 139 140 /** 141 * FIXME: Remove the return value check to align with the code 142 * before adding snd_dmaengine_pcm_refine_runtime_hwparams 143 * function. 144 */ 145 snd_dmaengine_pcm_refine_runtime_hwparams(substream, 146 dma_data, 147 &hw, 148 chan); 149 150 return snd_soc_set_runtime_hwparams(substream, &hw); 151 } 152 153 static int dmaengine_pcm_open(struct snd_soc_component *component, 154 struct snd_pcm_substream *substream) 155 { 156 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 157 struct dma_chan *chan = pcm->chan[substream->stream]; 158 int ret; 159 160 ret = dmaengine_pcm_set_runtime_hwparams(component, substream); 161 if (ret) 162 return ret; 163 164 return snd_dmaengine_pcm_open(substream, chan); 165 } 166 167 static int dmaengine_pcm_close(struct snd_soc_component *component, 168 struct snd_pcm_substream *substream) 169 { 170 return snd_dmaengine_pcm_close(substream); 171 } 172 173 static int dmaengine_pcm_hw_free(struct snd_soc_component *component, 174 struct snd_pcm_substream *substream) 175 { 176 return snd_pcm_lib_free_pages(substream); 177 } 178 179 static int dmaengine_pcm_trigger(struct snd_soc_component *component, 180 struct snd_pcm_substream *substream, int cmd) 181 { 182 return snd_dmaengine_pcm_trigger(substream, cmd); 183 } 184 185 static struct dma_chan *dmaengine_pcm_compat_request_channel( 186 struct snd_soc_component *component, 187 struct snd_soc_pcm_runtime *rtd, 188 struct snd_pcm_substream *substream) 189 { 190 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 191 struct snd_dmaengine_dai_dma_data *dma_data; 192 dma_filter_fn fn = NULL; 193 194 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 195 196 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0]) 197 return pcm->chan[0]; 198 199 if (pcm->config && pcm->config->compat_request_channel) 200 return pcm->config->compat_request_channel(rtd, substream); 201 202 if (pcm->config) 203 fn = pcm->config->compat_filter_fn; 204 205 return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data); 206 } 207 208 static bool dmaengine_pcm_can_report_residue(struct device *dev, 209 struct dma_chan *chan) 210 { 211 struct dma_slave_caps dma_caps; 212 int ret; 213 214 ret = dma_get_slave_caps(chan, &dma_caps); 215 if (ret != 0) { 216 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n", 217 ret); 218 return false; 219 } 220 221 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) 222 return false; 223 224 return true; 225 } 226 227 static int dmaengine_pcm_new(struct snd_soc_component *component, 228 struct snd_soc_pcm_runtime *rtd) 229 { 230 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 231 const struct snd_dmaengine_pcm_config *config = pcm->config; 232 struct device *dev = component->dev; 233 struct snd_pcm_substream *substream; 234 size_t prealloc_buffer_size; 235 size_t max_buffer_size; 236 unsigned int i; 237 238 if (config && config->prealloc_buffer_size) { 239 prealloc_buffer_size = config->prealloc_buffer_size; 240 max_buffer_size = config->pcm_hardware->buffer_bytes_max; 241 } else { 242 prealloc_buffer_size = 512 * 1024; 243 max_buffer_size = SIZE_MAX; 244 } 245 246 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { 247 substream = rtd->pcm->streams[i].substream; 248 if (!substream) 249 continue; 250 251 if (!pcm->chan[i] && config && config->chan_names[i]) 252 pcm->chan[i] = dma_request_slave_channel(dev, 253 config->chan_names[i]); 254 255 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) { 256 pcm->chan[i] = dmaengine_pcm_compat_request_channel( 257 component, rtd, substream); 258 } 259 260 if (!pcm->chan[i]) { 261 dev_err(component->dev, 262 "Missing dma channel for stream: %d\n", i); 263 return -EINVAL; 264 } 265 266 snd_pcm_lib_preallocate_pages(substream, 267 SNDRV_DMA_TYPE_DEV_IRAM, 268 dmaengine_dma_dev(pcm, substream), 269 prealloc_buffer_size, 270 max_buffer_size); 271 272 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i])) 273 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE; 274 275 if (rtd->pcm->streams[i].pcm->name[0] == '\0') { 276 strscpy_pad(rtd->pcm->streams[i].pcm->name, 277 rtd->pcm->streams[i].pcm->id, 278 sizeof(rtd->pcm->streams[i].pcm->name)); 279 } 280 } 281 282 return 0; 283 } 284 285 static snd_pcm_uframes_t dmaengine_pcm_pointer( 286 struct snd_soc_component *component, 287 struct snd_pcm_substream *substream) 288 { 289 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 290 291 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 292 return snd_dmaengine_pcm_pointer_no_residue(substream); 293 else 294 return snd_dmaengine_pcm_pointer(substream); 295 } 296 297 static int dmaengine_copy_user(struct snd_soc_component *component, 298 struct snd_pcm_substream *substream, 299 int channel, unsigned long hwoff, 300 void __user *buf, unsigned long bytes) 301 { 302 struct snd_pcm_runtime *runtime = substream->runtime; 303 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 304 int (*process)(struct snd_pcm_substream *substream, 305 int channel, unsigned long hwoff, 306 void *buf, unsigned long bytes) = pcm->config->process; 307 bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; 308 void *dma_ptr = runtime->dma_area + hwoff + 309 channel * (runtime->dma_bytes / runtime->channels); 310 int ret; 311 312 if (is_playback) 313 if (copy_from_user(dma_ptr, buf, bytes)) 314 return -EFAULT; 315 316 if (process) { 317 ret = process(substream, channel, hwoff, (__force void *)buf, bytes); 318 if (ret < 0) 319 return ret; 320 } 321 322 if (!is_playback) 323 if (copy_to_user(buf, dma_ptr, bytes)) 324 return -EFAULT; 325 326 return 0; 327 } 328 329 static const struct snd_soc_component_driver dmaengine_pcm_component = { 330 .name = SND_DMAENGINE_PCM_DRV_NAME, 331 .probe_order = SND_SOC_COMP_ORDER_LATE, 332 .open = dmaengine_pcm_open, 333 .close = dmaengine_pcm_close, 334 .ioctl = snd_soc_pcm_lib_ioctl, 335 .hw_params = dmaengine_pcm_hw_params, 336 .hw_free = dmaengine_pcm_hw_free, 337 .trigger = dmaengine_pcm_trigger, 338 .pointer = dmaengine_pcm_pointer, 339 .pcm_construct = dmaengine_pcm_new, 340 }; 341 342 static const struct snd_soc_component_driver dmaengine_pcm_component_process = { 343 .name = SND_DMAENGINE_PCM_DRV_NAME, 344 .probe_order = SND_SOC_COMP_ORDER_LATE, 345 .open = dmaengine_pcm_open, 346 .close = dmaengine_pcm_close, 347 .ioctl = snd_soc_pcm_lib_ioctl, 348 .hw_params = dmaengine_pcm_hw_params, 349 .hw_free = dmaengine_pcm_hw_free, 350 .trigger = dmaengine_pcm_trigger, 351 .pointer = dmaengine_pcm_pointer, 352 .copy_user = dmaengine_copy_user, 353 .pcm_construct = dmaengine_pcm_new, 354 }; 355 356 static const char * const dmaengine_pcm_dma_channel_names[] = { 357 [SNDRV_PCM_STREAM_PLAYBACK] = "tx", 358 [SNDRV_PCM_STREAM_CAPTURE] = "rx", 359 }; 360 361 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, 362 struct device *dev, const struct snd_dmaengine_pcm_config *config) 363 { 364 unsigned int i; 365 const char *name; 366 struct dma_chan *chan; 367 368 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node && 369 !(config && config->dma_dev && config->dma_dev->of_node))) 370 return 0; 371 372 if (config && config->dma_dev) { 373 /* 374 * If this warning is seen, it probably means that your Linux 375 * device structure does not match your HW device structure. 376 * It would be best to refactor the Linux device structure to 377 * correctly match the HW structure. 378 */ 379 dev_warn(dev, "DMA channels sourced from device %s", 380 dev_name(config->dma_dev)); 381 dev = config->dma_dev; 382 } 383 384 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 385 i++) { 386 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 387 name = "rx-tx"; 388 else 389 name = dmaengine_pcm_dma_channel_names[i]; 390 if (config && config->chan_names[i]) 391 name = config->chan_names[i]; 392 chan = dma_request_chan(dev, name); 393 if (IS_ERR(chan)) { 394 if (PTR_ERR(chan) == -EPROBE_DEFER) 395 return -EPROBE_DEFER; 396 pcm->chan[i] = NULL; 397 } else { 398 pcm->chan[i] = chan; 399 } 400 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 401 break; 402 } 403 404 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 405 pcm->chan[1] = pcm->chan[0]; 406 407 return 0; 408 } 409 410 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) 411 { 412 unsigned int i; 413 414 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 415 i++) { 416 if (!pcm->chan[i]) 417 continue; 418 dma_release_channel(pcm->chan[i]); 419 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 420 break; 421 } 422 } 423 424 /** 425 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device 426 * @dev: The parent device for the PCM device 427 * @config: Platform specific PCM configuration 428 * @flags: Platform specific quirks 429 */ 430 int snd_dmaengine_pcm_register(struct device *dev, 431 const struct snd_dmaengine_pcm_config *config, unsigned int flags) 432 { 433 struct dmaengine_pcm *pcm; 434 int ret; 435 436 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); 437 if (!pcm) 438 return -ENOMEM; 439 440 #ifdef CONFIG_DEBUG_FS 441 pcm->component.debugfs_prefix = "dma"; 442 #endif 443 pcm->config = config; 444 pcm->flags = flags; 445 446 ret = dmaengine_pcm_request_chan_of(pcm, dev, config); 447 if (ret) 448 goto err_free_dma; 449 450 if (config && config->process) 451 ret = snd_soc_add_component(dev, &pcm->component, 452 &dmaengine_pcm_component_process, 453 NULL, 0); 454 else 455 ret = snd_soc_add_component(dev, &pcm->component, 456 &dmaengine_pcm_component, NULL, 0); 457 if (ret) 458 goto err_free_dma; 459 460 return 0; 461 462 err_free_dma: 463 dmaengine_pcm_release_chan(pcm); 464 kfree(pcm); 465 return ret; 466 } 467 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); 468 469 /** 470 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device 471 * @dev: Parent device the PCM was register with 472 * 473 * Removes a dmaengine based PCM device previously registered with 474 * snd_dmaengine_pcm_register. 475 */ 476 void snd_dmaengine_pcm_unregister(struct device *dev) 477 { 478 struct snd_soc_component *component; 479 struct dmaengine_pcm *pcm; 480 481 component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME); 482 if (!component) 483 return; 484 485 pcm = soc_component_to_pcm(component); 486 487 snd_soc_unregister_component(dev); 488 dmaengine_pcm_release_chan(pcm); 489 kfree(pcm); 490 } 491 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); 492 493 MODULE_LICENSE("GPL"); 494