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 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm, 25 struct snd_pcm_substream *substream) 26 { 27 if (!pcm->chan[substream->stream]) 28 return NULL; 29 30 return pcm->chan[substream->stream]->device->dev; 31 } 32 33 /** 34 * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback 35 * @substream: PCM substream 36 * @params: hw_params 37 * @slave_config: DMA slave config to prepare 38 * 39 * This function can be used as a generic prepare_slave_config callback for 40 * platforms which make use of the snd_dmaengine_dai_dma_data struct for their 41 * DAI DMA data. Internally the function will first call 42 * snd_hwparams_to_dma_slave_config to fill in the slave config based on the 43 * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the 44 * remaining fields based on the DAI DMA data. 45 */ 46 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream, 47 struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config) 48 { 49 struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream); 50 struct snd_dmaengine_dai_dma_data *dma_data; 51 int ret; 52 53 if (rtd->num_cpus > 1) { 54 dev_err(rtd->dev, 55 "%s doesn't support Multi CPU yet\n", __func__); 56 return -EINVAL; 57 } 58 59 dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream); 60 61 ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config); 62 if (ret) 63 return ret; 64 65 snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data, 66 slave_config); 67 68 return 0; 69 } 70 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config); 71 72 static int dmaengine_pcm_hw_params(struct snd_soc_component *component, 73 struct snd_pcm_substream *substream, 74 struct snd_pcm_hw_params *params) 75 { 76 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 77 struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream); 78 int (*prepare_slave_config)(struct snd_pcm_substream *substream, 79 struct snd_pcm_hw_params *params, 80 struct dma_slave_config *slave_config); 81 struct dma_slave_config slave_config; 82 int ret; 83 84 memset(&slave_config, 0, sizeof(slave_config)); 85 86 if (!pcm->config) 87 prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config; 88 else 89 prepare_slave_config = pcm->config->prepare_slave_config; 90 91 if (prepare_slave_config) { 92 ret = prepare_slave_config(substream, params, &slave_config); 93 if (ret) 94 return ret; 95 96 ret = dmaengine_slave_config(chan, &slave_config); 97 if (ret) 98 return ret; 99 } 100 101 return 0; 102 } 103 104 static int 105 dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component, 106 struct snd_pcm_substream *substream) 107 { 108 struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream); 109 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 110 struct device *dma_dev = dmaengine_dma_dev(pcm, substream); 111 struct dma_chan *chan = pcm->chan[substream->stream]; 112 struct snd_dmaengine_dai_dma_data *dma_data; 113 struct snd_pcm_hardware hw; 114 115 if (rtd->num_cpus > 1) { 116 dev_err(rtd->dev, 117 "%s doesn't support Multi CPU yet\n", __func__); 118 return -EINVAL; 119 } 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(asoc_rtd_to_cpu(rtd, 0), 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 if (rtd->num_cpus > 1) { 189 dev_err(rtd->dev, 190 "%s doesn't support Multi CPU yet\n", __func__); 191 return NULL; 192 } 193 194 dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), 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_each_pcm_streams(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_set_managed_buffer(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 .hw_params = dmaengine_pcm_hw_params, 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 .hw_params = dmaengine_pcm_hw_params, 346 .trigger = dmaengine_pcm_trigger, 347 .pointer = dmaengine_pcm_pointer, 348 .copy_user = dmaengine_copy_user, 349 .pcm_construct = dmaengine_pcm_new, 350 }; 351 352 static const char * const dmaengine_pcm_dma_channel_names[] = { 353 [SNDRV_PCM_STREAM_PLAYBACK] = "tx", 354 [SNDRV_PCM_STREAM_CAPTURE] = "rx", 355 }; 356 357 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, 358 struct device *dev, const struct snd_dmaengine_pcm_config *config) 359 { 360 unsigned int i; 361 const char *name; 362 struct dma_chan *chan; 363 364 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node && 365 !(config && config->dma_dev && config->dma_dev->of_node))) 366 return 0; 367 368 if (config && config->dma_dev) { 369 /* 370 * If this warning is seen, it probably means that your Linux 371 * device structure does not match your HW device structure. 372 * It would be best to refactor the Linux device structure to 373 * correctly match the HW structure. 374 */ 375 dev_warn(dev, "DMA channels sourced from device %s", 376 dev_name(config->dma_dev)); 377 dev = config->dma_dev; 378 } 379 380 for_each_pcm_streams(i) { 381 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 382 name = "rx-tx"; 383 else 384 name = dmaengine_pcm_dma_channel_names[i]; 385 if (config && config->chan_names[i]) 386 name = config->chan_names[i]; 387 chan = dma_request_chan(dev, name); 388 if (IS_ERR(chan)) { 389 /* 390 * Only report probe deferral errors, channels 391 * might not be present for devices that 392 * support only TX or only RX. 393 */ 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_each_pcm_streams(i) { 415 if (!pcm->chan[i]) 416 continue; 417 dma_release_channel(pcm->chan[i]); 418 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 419 break; 420 } 421 } 422 423 /** 424 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device 425 * @dev: The parent device for the PCM device 426 * @config: Platform specific PCM configuration 427 * @flags: Platform specific quirks 428 */ 429 int snd_dmaengine_pcm_register(struct device *dev, 430 const struct snd_dmaengine_pcm_config *config, unsigned int flags) 431 { 432 const struct snd_soc_component_driver *driver; 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 driver = &dmaengine_pcm_component_process; 452 else 453 driver = &dmaengine_pcm_component; 454 455 ret = snd_soc_component_initialize(&pcm->component, driver, dev); 456 if (ret) 457 goto err_free_dma; 458 459 ret = snd_soc_add_component(&pcm->component, NULL, 0); 460 if (ret) 461 goto err_free_dma; 462 463 return 0; 464 465 err_free_dma: 466 dmaengine_pcm_release_chan(pcm); 467 kfree(pcm); 468 return ret; 469 } 470 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); 471 472 /** 473 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device 474 * @dev: Parent device the PCM was register with 475 * 476 * Removes a dmaengine based PCM device previously registered with 477 * snd_dmaengine_pcm_register. 478 */ 479 void snd_dmaengine_pcm_unregister(struct device *dev) 480 { 481 struct snd_soc_component *component; 482 struct dmaengine_pcm *pcm; 483 484 component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME); 485 if (!component) 486 return; 487 488 pcm = soc_component_to_pcm(component); 489 490 snd_soc_unregister_component_by_driver(dev, component->driver); 491 dmaengine_pcm_release_chan(pcm); 492 kfree(pcm); 493 } 494 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); 495 496 MODULE_LICENSE("GPL"); 497