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 if (rtd->num_cpus > 1) { 66 dev_err(rtd->dev, 67 "%s doesn't support Multi CPU yet\n", __func__); 68 return -EINVAL; 69 } 70 71 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 72 73 ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config); 74 if (ret) 75 return ret; 76 77 snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data, 78 slave_config); 79 80 return 0; 81 } 82 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config); 83 84 static int dmaengine_pcm_hw_params(struct snd_soc_component *component, 85 struct snd_pcm_substream *substream, 86 struct snd_pcm_hw_params *params) 87 { 88 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 89 struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream); 90 int (*prepare_slave_config)(struct snd_pcm_substream *substream, 91 struct snd_pcm_hw_params *params, 92 struct dma_slave_config *slave_config); 93 struct dma_slave_config slave_config; 94 int ret; 95 96 memset(&slave_config, 0, sizeof(slave_config)); 97 98 if (!pcm->config) 99 prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config; 100 else 101 prepare_slave_config = pcm->config->prepare_slave_config; 102 103 if (prepare_slave_config) { 104 ret = prepare_slave_config(substream, params, &slave_config); 105 if (ret) 106 return ret; 107 108 ret = dmaengine_slave_config(chan, &slave_config); 109 if (ret) 110 return ret; 111 } 112 113 return 0; 114 } 115 116 static int 117 dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component, 118 struct snd_pcm_substream *substream) 119 { 120 struct snd_soc_pcm_runtime *rtd = substream->private_data; 121 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 122 struct device *dma_dev = dmaengine_dma_dev(pcm, substream); 123 struct dma_chan *chan = pcm->chan[substream->stream]; 124 struct snd_dmaengine_dai_dma_data *dma_data; 125 struct snd_pcm_hardware hw; 126 127 if (rtd->num_cpus > 1) { 128 dev_err(rtd->dev, 129 "%s doesn't support Multi CPU yet\n", __func__); 130 return -EINVAL; 131 } 132 133 if (pcm->config && pcm->config->pcm_hardware) 134 return snd_soc_set_runtime_hwparams(substream, 135 pcm->config->pcm_hardware); 136 137 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 138 139 memset(&hw, 0, sizeof(hw)); 140 hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | 141 SNDRV_PCM_INFO_INTERLEAVED; 142 hw.periods_min = 2; 143 hw.periods_max = UINT_MAX; 144 hw.period_bytes_min = 256; 145 hw.period_bytes_max = dma_get_max_seg_size(dma_dev); 146 hw.buffer_bytes_max = SIZE_MAX; 147 hw.fifo_size = dma_data->fifo_size; 148 149 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 150 hw.info |= SNDRV_PCM_INFO_BATCH; 151 152 /** 153 * FIXME: Remove the return value check to align with the code 154 * before adding snd_dmaengine_pcm_refine_runtime_hwparams 155 * function. 156 */ 157 snd_dmaengine_pcm_refine_runtime_hwparams(substream, 158 dma_data, 159 &hw, 160 chan); 161 162 return snd_soc_set_runtime_hwparams(substream, &hw); 163 } 164 165 static int dmaengine_pcm_open(struct snd_soc_component *component, 166 struct snd_pcm_substream *substream) 167 { 168 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 169 struct dma_chan *chan = pcm->chan[substream->stream]; 170 int ret; 171 172 ret = dmaengine_pcm_set_runtime_hwparams(component, substream); 173 if (ret) 174 return ret; 175 176 return snd_dmaengine_pcm_open(substream, chan); 177 } 178 179 static int dmaengine_pcm_close(struct snd_soc_component *component, 180 struct snd_pcm_substream *substream) 181 { 182 return snd_dmaengine_pcm_close(substream); 183 } 184 185 static int dmaengine_pcm_trigger(struct snd_soc_component *component, 186 struct snd_pcm_substream *substream, int cmd) 187 { 188 return snd_dmaengine_pcm_trigger(substream, cmd); 189 } 190 191 static struct dma_chan *dmaengine_pcm_compat_request_channel( 192 struct snd_soc_component *component, 193 struct snd_soc_pcm_runtime *rtd, 194 struct snd_pcm_substream *substream) 195 { 196 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 197 struct snd_dmaengine_dai_dma_data *dma_data; 198 dma_filter_fn fn = NULL; 199 200 if (rtd->num_cpus > 1) { 201 dev_err(rtd->dev, 202 "%s doesn't support Multi CPU yet\n", __func__); 203 return NULL; 204 } 205 206 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 207 208 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0]) 209 return pcm->chan[0]; 210 211 if (pcm->config && pcm->config->compat_request_channel) 212 return pcm->config->compat_request_channel(rtd, substream); 213 214 if (pcm->config) 215 fn = pcm->config->compat_filter_fn; 216 217 return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data); 218 } 219 220 static bool dmaengine_pcm_can_report_residue(struct device *dev, 221 struct dma_chan *chan) 222 { 223 struct dma_slave_caps dma_caps; 224 int ret; 225 226 ret = dma_get_slave_caps(chan, &dma_caps); 227 if (ret != 0) { 228 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n", 229 ret); 230 return false; 231 } 232 233 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) 234 return false; 235 236 return true; 237 } 238 239 static int dmaengine_pcm_new(struct snd_soc_component *component, 240 struct snd_soc_pcm_runtime *rtd) 241 { 242 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 243 const struct snd_dmaengine_pcm_config *config = pcm->config; 244 struct device *dev = component->dev; 245 struct snd_pcm_substream *substream; 246 size_t prealloc_buffer_size; 247 size_t max_buffer_size; 248 unsigned int i; 249 250 if (config && config->prealloc_buffer_size) { 251 prealloc_buffer_size = config->prealloc_buffer_size; 252 max_buffer_size = config->pcm_hardware->buffer_bytes_max; 253 } else { 254 prealloc_buffer_size = 512 * 1024; 255 max_buffer_size = SIZE_MAX; 256 } 257 258 for_each_pcm_streams(i) { 259 substream = rtd->pcm->streams[i].substream; 260 if (!substream) 261 continue; 262 263 if (!pcm->chan[i] && config && config->chan_names[i]) 264 pcm->chan[i] = dma_request_slave_channel(dev, 265 config->chan_names[i]); 266 267 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) { 268 pcm->chan[i] = dmaengine_pcm_compat_request_channel( 269 component, rtd, substream); 270 } 271 272 if (!pcm->chan[i]) { 273 dev_err(component->dev, 274 "Missing dma channel for stream: %d\n", i); 275 return -EINVAL; 276 } 277 278 snd_pcm_set_managed_buffer(substream, 279 SNDRV_DMA_TYPE_DEV_IRAM, 280 dmaengine_dma_dev(pcm, substream), 281 prealloc_buffer_size, 282 max_buffer_size); 283 284 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i])) 285 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE; 286 287 if (rtd->pcm->streams[i].pcm->name[0] == '\0') { 288 strscpy_pad(rtd->pcm->streams[i].pcm->name, 289 rtd->pcm->streams[i].pcm->id, 290 sizeof(rtd->pcm->streams[i].pcm->name)); 291 } 292 } 293 294 return 0; 295 } 296 297 static snd_pcm_uframes_t dmaengine_pcm_pointer( 298 struct snd_soc_component *component, 299 struct snd_pcm_substream *substream) 300 { 301 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 302 303 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 304 return snd_dmaengine_pcm_pointer_no_residue(substream); 305 else 306 return snd_dmaengine_pcm_pointer(substream); 307 } 308 309 static int dmaengine_copy_user(struct snd_soc_component *component, 310 struct snd_pcm_substream *substream, 311 int channel, unsigned long hwoff, 312 void __user *buf, unsigned long bytes) 313 { 314 struct snd_pcm_runtime *runtime = substream->runtime; 315 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 316 int (*process)(struct snd_pcm_substream *substream, 317 int channel, unsigned long hwoff, 318 void *buf, unsigned long bytes) = pcm->config->process; 319 bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; 320 void *dma_ptr = runtime->dma_area + hwoff + 321 channel * (runtime->dma_bytes / runtime->channels); 322 int ret; 323 324 if (is_playback) 325 if (copy_from_user(dma_ptr, buf, bytes)) 326 return -EFAULT; 327 328 if (process) { 329 ret = process(substream, channel, hwoff, (__force void *)buf, bytes); 330 if (ret < 0) 331 return ret; 332 } 333 334 if (!is_playback) 335 if (copy_to_user(buf, dma_ptr, bytes)) 336 return -EFAULT; 337 338 return 0; 339 } 340 341 static const struct snd_soc_component_driver dmaengine_pcm_component = { 342 .name = SND_DMAENGINE_PCM_DRV_NAME, 343 .probe_order = SND_SOC_COMP_ORDER_LATE, 344 .open = dmaengine_pcm_open, 345 .close = dmaengine_pcm_close, 346 .hw_params = dmaengine_pcm_hw_params, 347 .trigger = dmaengine_pcm_trigger, 348 .pointer = dmaengine_pcm_pointer, 349 .pcm_construct = dmaengine_pcm_new, 350 }; 351 352 static const struct snd_soc_component_driver dmaengine_pcm_component_process = { 353 .name = SND_DMAENGINE_PCM_DRV_NAME, 354 .probe_order = SND_SOC_COMP_ORDER_LATE, 355 .open = dmaengine_pcm_open, 356 .close = dmaengine_pcm_close, 357 .hw_params = dmaengine_pcm_hw_params, 358 .trigger = dmaengine_pcm_trigger, 359 .pointer = dmaengine_pcm_pointer, 360 .copy_user = dmaengine_copy_user, 361 .pcm_construct = dmaengine_pcm_new, 362 }; 363 364 static const char * const dmaengine_pcm_dma_channel_names[] = { 365 [SNDRV_PCM_STREAM_PLAYBACK] = "tx", 366 [SNDRV_PCM_STREAM_CAPTURE] = "rx", 367 }; 368 369 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, 370 struct device *dev, const struct snd_dmaengine_pcm_config *config) 371 { 372 unsigned int i; 373 const char *name; 374 struct dma_chan *chan; 375 376 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node && 377 !(config && config->dma_dev && config->dma_dev->of_node))) 378 return 0; 379 380 if (config && config->dma_dev) { 381 /* 382 * If this warning is seen, it probably means that your Linux 383 * device structure does not match your HW device structure. 384 * It would be best to refactor the Linux device structure to 385 * correctly match the HW structure. 386 */ 387 dev_warn(dev, "DMA channels sourced from device %s", 388 dev_name(config->dma_dev)); 389 dev = config->dma_dev; 390 } 391 392 for_each_pcm_streams(i) { 393 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 394 name = "rx-tx"; 395 else 396 name = dmaengine_pcm_dma_channel_names[i]; 397 if (config && config->chan_names[i]) 398 name = config->chan_names[i]; 399 chan = dma_request_chan(dev, name); 400 if (IS_ERR(chan)) { 401 if (PTR_ERR(chan) == -EPROBE_DEFER) 402 return -EPROBE_DEFER; 403 pcm->chan[i] = NULL; 404 } else { 405 pcm->chan[i] = chan; 406 } 407 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 408 break; 409 } 410 411 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 412 pcm->chan[1] = pcm->chan[0]; 413 414 return 0; 415 } 416 417 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) 418 { 419 unsigned int i; 420 421 for_each_pcm_streams(i) { 422 if (!pcm->chan[i]) 423 continue; 424 dma_release_channel(pcm->chan[i]); 425 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 426 break; 427 } 428 } 429 430 /** 431 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device 432 * @dev: The parent device for the PCM device 433 * @config: Platform specific PCM configuration 434 * @flags: Platform specific quirks 435 */ 436 int snd_dmaengine_pcm_register(struct device *dev, 437 const struct snd_dmaengine_pcm_config *config, unsigned int flags) 438 { 439 struct dmaengine_pcm *pcm; 440 int ret; 441 442 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); 443 if (!pcm) 444 return -ENOMEM; 445 446 #ifdef CONFIG_DEBUG_FS 447 pcm->component.debugfs_prefix = "dma"; 448 #endif 449 pcm->config = config; 450 pcm->flags = flags; 451 452 ret = dmaengine_pcm_request_chan_of(pcm, dev, config); 453 if (ret) 454 goto err_free_dma; 455 456 if (config && config->process) 457 ret = snd_soc_add_component(dev, &pcm->component, 458 &dmaengine_pcm_component_process, 459 NULL, 0); 460 else 461 ret = snd_soc_add_component(dev, &pcm->component, 462 &dmaengine_pcm_component, NULL, 0); 463 if (ret) 464 goto err_free_dma; 465 466 return 0; 467 468 err_free_dma: 469 dmaengine_pcm_release_chan(pcm); 470 kfree(pcm); 471 return ret; 472 } 473 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); 474 475 /** 476 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device 477 * @dev: Parent device the PCM was register with 478 * 479 * Removes a dmaengine based PCM device previously registered with 480 * snd_dmaengine_pcm_register. 481 */ 482 void snd_dmaengine_pcm_unregister(struct device *dev) 483 { 484 struct snd_soc_component *component; 485 struct dmaengine_pcm *pcm; 486 487 component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME); 488 if (!component) 489 return; 490 491 pcm = soc_component_to_pcm(component); 492 493 snd_soc_unregister_component(dev); 494 dmaengine_pcm_release_chan(pcm); 495 kfree(pcm); 496 } 497 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); 498 499 MODULE_LICENSE("GPL"); 500