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