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/acpi.h> 7 #include <linux/module.h> 8 #include <linux/init.h> 9 #include <linux/dmaengine.h> 10 #include <linux/slab.h> 11 #include <sound/pcm.h> 12 #include <sound/pcm_params.h> 13 #include <sound/soc.h> 14 #include <linux/dma-mapping.h> 15 #include <linux/of.h> 16 17 #include <sound/dmaengine_pcm.h> 18 19 static unsigned int prealloc_buffer_size_kbytes = 512; 20 module_param(prealloc_buffer_size_kbytes, uint, 0444); 21 MODULE_PARM_DESC(prealloc_buffer_size_kbytes, "Preallocate DMA buffer size (KB)."); 22 23 /* 24 * The platforms dmaengine driver does not support reporting the amount of 25 * bytes that are still left to transfer. 26 */ 27 #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31) 28 29 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm, 30 struct snd_pcm_substream *substream) 31 { 32 if (!pcm->chan[substream->stream]) 33 return NULL; 34 35 return pcm->chan[substream->stream]->device->dev; 36 } 37 38 /** 39 * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback 40 * @substream: PCM substream 41 * @params: hw_params 42 * @slave_config: DMA slave config to prepare 43 * 44 * This function can be used as a generic prepare_slave_config callback for 45 * platforms which make use of the snd_dmaengine_dai_dma_data struct for their 46 * DAI DMA data. Internally the function will first call 47 * snd_hwparams_to_dma_slave_config to fill in the slave config based on the 48 * hw_params, followed by snd_dmaengine_pcm_set_config_from_dai_data to fill in 49 * the remaining fields based on the DAI DMA data. 50 */ 51 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream, 52 struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config) 53 { 54 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream); 55 struct snd_dmaengine_dai_dma_data *dma_data; 56 int ret; 57 58 if (rtd->dai_link->num_cpus > 1) { 59 dev_err(rtd->dev, 60 "%s doesn't support Multi CPU yet\n", __func__); 61 return -EINVAL; 62 } 63 64 dma_data = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream); 65 66 ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config); 67 if (ret) 68 return ret; 69 70 snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data, 71 slave_config); 72 73 return 0; 74 } 75 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config); 76 77 static int dmaengine_pcm_hw_params(struct snd_soc_component *component, 78 struct snd_pcm_substream *substream, 79 struct snd_pcm_hw_params *params) 80 { 81 struct dmaengine_pcm *pcm = snd_soc_component_to_priv(component); 82 struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream); 83 struct dma_slave_config slave_config; 84 int ret; 85 86 if (!pcm->config->prepare_slave_config) 87 return 0; 88 89 memset(&slave_config, 0, sizeof(slave_config)); 90 91 ret = pcm->config->prepare_slave_config(substream, params, &slave_config); 92 if (ret) 93 return ret; 94 95 return dmaengine_slave_config(chan, &slave_config); 96 } 97 98 static int 99 dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component, 100 struct snd_pcm_substream *substream) 101 { 102 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream); 103 struct dmaengine_pcm *pcm = snd_soc_component_to_priv(component); 104 struct device *dma_dev = dmaengine_dma_dev(pcm, substream); 105 struct dma_chan *chan = pcm->chan[substream->stream]; 106 struct snd_dmaengine_dai_dma_data *dma_data; 107 struct snd_pcm_hardware hw; 108 109 if (rtd->dai_link->num_cpus > 1) { 110 dev_err(rtd->dev, 111 "%s doesn't support Multi CPU yet\n", __func__); 112 return -EINVAL; 113 } 114 115 if (pcm->config->pcm_hardware) 116 return snd_soc_set_runtime_hwparams(substream, 117 pcm->config->pcm_hardware); 118 119 dma_data = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream); 120 121 memset(&hw, 0, sizeof(hw)); 122 hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | 123 SNDRV_PCM_INFO_INTERLEAVED; 124 hw.periods_min = 2; 125 hw.periods_max = UINT_MAX; 126 hw.period_bytes_min = dma_data->maxburst * DMA_SLAVE_BUSWIDTH_8_BYTES; 127 if (!hw.period_bytes_min) 128 hw.period_bytes_min = 256; 129 hw.period_bytes_max = dma_get_max_seg_size(dma_dev); 130 hw.buffer_bytes_max = SIZE_MAX; 131 hw.fifo_size = dma_data->fifo_size; 132 133 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 134 hw.info |= SNDRV_PCM_INFO_BATCH; 135 136 /** 137 * FIXME: Remove the return value check to align with the code 138 * before adding snd_dmaengine_pcm_refine_runtime_hwparams 139 * function. 140 */ 141 snd_dmaengine_pcm_refine_runtime_hwparams(substream, 142 dma_data, 143 &hw, 144 chan); 145 146 return snd_soc_set_runtime_hwparams(substream, &hw); 147 } 148 149 static int dmaengine_pcm_open(struct snd_soc_component *component, 150 struct snd_pcm_substream *substream) 151 { 152 struct dmaengine_pcm *pcm = snd_soc_component_to_priv(component); 153 struct dma_chan *chan = pcm->chan[substream->stream]; 154 int ret; 155 156 ret = dmaengine_pcm_set_runtime_hwparams(component, substream); 157 if (ret) 158 return ret; 159 160 return snd_dmaengine_pcm_open(substream, chan); 161 } 162 163 static int dmaengine_pcm_close(struct snd_soc_component *component, 164 struct snd_pcm_substream *substream) 165 { 166 return snd_dmaengine_pcm_close(substream); 167 } 168 169 static int dmaengine_pcm_trigger(struct snd_soc_component *component, 170 struct snd_pcm_substream *substream, int cmd) 171 { 172 return snd_dmaengine_pcm_trigger(substream, cmd); 173 } 174 175 static struct dma_chan *dmaengine_pcm_compat_request_channel( 176 struct snd_soc_component *component, 177 struct snd_soc_pcm_runtime *rtd, 178 struct snd_pcm_substream *substream) 179 { 180 struct dmaengine_pcm *pcm = snd_soc_component_to_priv(component); 181 struct snd_dmaengine_dai_dma_data *dma_data; 182 183 if (rtd->dai_link->num_cpus > 1) { 184 dev_err(rtd->dev, 185 "%s doesn't support Multi CPU yet\n", __func__); 186 return NULL; 187 } 188 189 dma_data = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream); 190 191 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0]) 192 return pcm->chan[0]; 193 194 if (pcm->config->compat_request_channel) 195 return pcm->config->compat_request_channel(rtd, substream); 196 197 return snd_dmaengine_pcm_request_channel(pcm->config->compat_filter_fn, 198 dma_data->filter_data); 199 } 200 201 static bool dmaengine_pcm_can_report_residue(struct device *dev, 202 struct dma_chan *chan) 203 { 204 struct dma_slave_caps dma_caps; 205 int ret; 206 207 ret = dma_get_slave_caps(chan, &dma_caps); 208 if (ret != 0) { 209 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n", 210 ret); 211 return false; 212 } 213 214 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) 215 return false; 216 217 return true; 218 } 219 220 static int dmaengine_pcm_new(struct snd_soc_component *component, 221 struct snd_soc_pcm_runtime *rtd) 222 { 223 struct dmaengine_pcm *pcm = snd_soc_component_to_priv(component); 224 const struct snd_dmaengine_pcm_config *config = pcm->config; 225 struct device *dev = component->dev; 226 size_t prealloc_buffer_size; 227 size_t max_buffer_size; 228 unsigned int i; 229 230 if (config->prealloc_buffer_size) 231 prealloc_buffer_size = config->prealloc_buffer_size; 232 else 233 prealloc_buffer_size = prealloc_buffer_size_kbytes * 1024; 234 235 if (config->pcm_hardware && config->pcm_hardware->buffer_bytes_max) 236 max_buffer_size = config->pcm_hardware->buffer_bytes_max; 237 else 238 max_buffer_size = SIZE_MAX; 239 240 for_each_pcm_streams(i) { 241 struct snd_pcm_substream *substream = rtd->pcm->streams[i].substream; 242 if (!substream) 243 continue; 244 245 if (!pcm->chan[i] && 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 = snd_soc_component_to_priv(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(struct snd_soc_component *component, 292 struct snd_pcm_substream *substream, 293 int channel, unsigned long hwoff, 294 struct iov_iter *iter, unsigned long bytes) 295 { 296 struct snd_pcm_runtime *runtime = substream->runtime; 297 struct dmaengine_pcm *pcm = snd_soc_component_to_priv(component); 298 int (*process)(struct snd_pcm_substream *substream, 299 int channel, unsigned long hwoff, 300 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); 304 305 if (is_playback) 306 if (copy_from_iter(dma_ptr, bytes, iter) != bytes) 307 return -EFAULT; 308 309 if (process) { 310 int ret = process(substream, channel, hwoff, bytes); 311 if (ret < 0) 312 return ret; 313 } 314 315 if (!is_playback) 316 if (copy_to_iter(dma_ptr, bytes, iter) != bytes) 317 return -EFAULT; 318 319 return 0; 320 } 321 322 static int dmaengine_pcm_sync_stop(struct snd_soc_component *component, 323 struct snd_pcm_substream *substream) 324 { 325 return snd_dmaengine_pcm_sync_stop(substream); 326 } 327 328 static const struct snd_soc_component_driver dmaengine_pcm_component = { 329 .name = SND_DMAENGINE_PCM_DRV_NAME, 330 .probe_order = SND_SOC_COMP_ORDER_LATE, 331 .open = dmaengine_pcm_open, 332 .close = dmaengine_pcm_close, 333 .hw_params = dmaengine_pcm_hw_params, 334 .trigger = dmaengine_pcm_trigger, 335 .pointer = dmaengine_pcm_pointer, 336 .pcm_new = dmaengine_pcm_new, 337 .sync_stop = dmaengine_pcm_sync_stop, 338 .debugfs_prefix = "dma", 339 }; 340 341 static const struct snd_soc_component_driver dmaengine_pcm_component_process = { 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 .copy = dmaengine_copy, 350 .pcm_new = dmaengine_pcm_new, 351 .sync_stop = dmaengine_pcm_sync_stop, 352 .debugfs_prefix = "dma", 353 }; 354 355 static const char * const dmaengine_pcm_dma_channel_names[] = { 356 [SNDRV_PCM_STREAM_PLAYBACK] = "tx", 357 [SNDRV_PCM_STREAM_CAPTURE] = "rx", 358 }; 359 360 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, 361 struct device *dev, const struct snd_dmaengine_pcm_config *config) 362 { 363 unsigned int i; 364 const char *name; 365 struct dma_chan *chan; 366 367 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node && 368 !(config->dma_dev && config->dma_dev->of_node))) 369 return 0; 370 371 if (config->dma_dev) { 372 /* 373 * If this warning is seen, it probably means that your Linux 374 * device structure does not match your HW device structure. 375 * It would be best to refactor the Linux device structure to 376 * correctly match the HW structure. 377 */ 378 dev_warn(dev, "DMA channels sourced from device %s", 379 dev_name(config->dma_dev)); 380 dev = config->dma_dev; 381 } 382 383 for_each_pcm_streams(i) { 384 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 385 name = "rx-tx"; 386 else 387 name = dmaengine_pcm_dma_channel_names[i]; 388 if (config->chan_names[i]) 389 name = config->chan_names[i]; 390 chan = dma_request_chan(dev, name); 391 if (IS_ERR(chan)) { 392 /* 393 * Only report probe deferral errors, channels 394 * might not be present for devices that 395 * support only TX or only RX. 396 */ 397 if (PTR_ERR(chan) == -EPROBE_DEFER) 398 return -EPROBE_DEFER; 399 400 if (device_property_match_string(dev, "dma-names", name) >= 0) 401 dev_warn(dev, "dma-names has '%s' but request failed (%ld)\n", 402 name, PTR_ERR(chan)); 403 404 pcm->chan[i] = NULL; 405 } else { 406 pcm->chan[i] = chan; 407 } 408 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 409 break; 410 } 411 412 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 413 pcm->chan[1] = pcm->chan[0]; 414 415 if (!pcm->chan[0] && 416 !pcm->chan[1]) { 417 dev_err(dev, "no DMA channel found for either playback or capture\n"); 418 return -ENODEV; 419 } 420 421 return 0; 422 } 423 424 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) 425 { 426 unsigned int i; 427 428 for_each_pcm_streams(i) { 429 if (!pcm->chan[i]) 430 continue; 431 dma_release_channel(pcm->chan[i]); 432 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 433 break; 434 } 435 } 436 437 static const struct snd_dmaengine_pcm_config snd_dmaengine_pcm_default_config = { 438 .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config, 439 }; 440 441 /** 442 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device 443 * @dev: The parent device for the PCM device 444 * @config: Platform specific PCM configuration 445 * @flags: Platform specific quirks 446 */ 447 int snd_dmaengine_pcm_register(struct device *dev, 448 const struct snd_dmaengine_pcm_config *config, unsigned int flags) 449 { 450 struct snd_soc_component *component; 451 const struct snd_soc_component_driver *driver; 452 struct dmaengine_pcm *pcm; 453 int ret; 454 455 component = snd_soc_component_alloc(dev); 456 if (!component) 457 return -ENOMEM; 458 459 pcm = kzalloc_obj(*pcm); 460 if (!pcm) 461 return -ENOMEM; 462 463 if (!config) 464 config = &snd_dmaengine_pcm_default_config; 465 pcm->config = config; 466 pcm->flags = flags; 467 468 if (config->name) 469 snd_soc_component_set_name(component, config->name); 470 snd_soc_component_set_priv(component, pcm); 471 472 ret = dmaengine_pcm_request_chan_of(pcm, dev, config); 473 if (ret) 474 goto err_free_dma; 475 476 if (config->process) 477 driver = &dmaengine_pcm_component_process; 478 else 479 driver = &dmaengine_pcm_component; 480 481 ret = snd_soc_register_component(component, driver, NULL, 0); 482 if (ret) 483 goto err_free_dma; 484 485 return 0; 486 487 err_free_dma: 488 dmaengine_pcm_release_chan(pcm); 489 kfree(pcm); 490 return ret; 491 } 492 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); 493 494 /** 495 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device 496 * @dev: Parent device the PCM was register with 497 * 498 * Removes a dmaengine based PCM device previously registered with 499 * snd_dmaengine_pcm_register. 500 */ 501 void snd_dmaengine_pcm_unregister(struct device *dev) 502 { 503 struct snd_soc_component *component; 504 struct dmaengine_pcm *pcm; 505 506 component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME); 507 if (!component) 508 return; 509 510 pcm = snd_soc_component_to_priv(component); 511 512 snd_soc_unregister_component_by_driver(dev, component->driver); 513 dmaengine_pcm_release_chan(pcm); 514 kfree(pcm); 515 } 516 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); 517 518 MODULE_DESCRIPTION("ASoC helpers for generic PCM dmaengine API"); 519 MODULE_LICENSE("GPL"); 520