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