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