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 static unsigned int prealloc_buffer_size_kbytes = 512; 19 module_param(prealloc_buffer_size_kbytes, uint, 0444); 20 MODULE_PARM_DESC(prealloc_buffer_size_kbytes, "Preallocate DMA buffer size (KB)."); 21 22 /* 23 * The platforms dmaengine driver does not support reporting the amount of 24 * bytes that are still left to transfer. 25 */ 26 #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31) 27 28 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm, 29 struct snd_pcm_substream *substream) 30 { 31 if (!pcm->chan[substream->stream]) 32 return NULL; 33 34 return pcm->chan[substream->stream]->device->dev; 35 } 36 37 /** 38 * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback 39 * @substream: PCM substream 40 * @params: hw_params 41 * @slave_config: DMA slave config to prepare 42 * 43 * This function can be used as a generic prepare_slave_config callback for 44 * platforms which make use of the snd_dmaengine_dai_dma_data struct for their 45 * DAI DMA data. Internally the function will first call 46 * snd_hwparams_to_dma_slave_config to fill in the slave config based on the 47 * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the 48 * remaining fields based on the DAI DMA data. 49 */ 50 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream, 51 struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config) 52 { 53 struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream); 54 struct snd_dmaengine_dai_dma_data *dma_data; 55 int ret; 56 57 if (rtd->dai_link->num_cpus > 1) { 58 dev_err(rtd->dev, 59 "%s doesn't support Multi CPU yet\n", __func__); 60 return -EINVAL; 61 } 62 63 dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream); 64 65 ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config); 66 if (ret) 67 return ret; 68 69 snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data, 70 slave_config); 71 72 return 0; 73 } 74 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config); 75 76 static int dmaengine_pcm_hw_params(struct snd_soc_component *component, 77 struct snd_pcm_substream *substream, 78 struct snd_pcm_hw_params *params) 79 { 80 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 81 struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream); 82 struct dma_slave_config slave_config; 83 int ret; 84 85 if (!pcm->config->prepare_slave_config) 86 return 0; 87 88 memset(&slave_config, 0, sizeof(slave_config)); 89 90 ret = pcm->config->prepare_slave_config(substream, params, &slave_config); 91 if (ret) 92 return ret; 93 94 return dmaengine_slave_config(chan, &slave_config); 95 } 96 97 static int 98 dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component, 99 struct snd_pcm_substream *substream) 100 { 101 struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream); 102 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 103 struct device *dma_dev = dmaengine_dma_dev(pcm, substream); 104 struct dma_chan *chan = pcm->chan[substream->stream]; 105 struct snd_dmaengine_dai_dma_data *dma_data; 106 struct snd_pcm_hardware hw; 107 108 if (rtd->dai_link->num_cpus > 1) { 109 dev_err(rtd->dev, 110 "%s doesn't support Multi CPU yet\n", __func__); 111 return -EINVAL; 112 } 113 114 if (pcm->config->pcm_hardware) 115 return snd_soc_set_runtime_hwparams(substream, 116 pcm->config->pcm_hardware); 117 118 dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream); 119 120 memset(&hw, 0, sizeof(hw)); 121 hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | 122 SNDRV_PCM_INFO_INTERLEAVED; 123 hw.periods_min = 2; 124 hw.periods_max = UINT_MAX; 125 hw.period_bytes_min = dma_data->maxburst * DMA_SLAVE_BUSWIDTH_8_BYTES; 126 if (!hw.period_bytes_min) 127 hw.period_bytes_min = 256; 128 hw.period_bytes_max = dma_get_max_seg_size(dma_dev); 129 hw.buffer_bytes_max = SIZE_MAX; 130 hw.fifo_size = dma_data->fifo_size; 131 132 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 133 hw.info |= SNDRV_PCM_INFO_BATCH; 134 135 /** 136 * FIXME: Remove the return value check to align with the code 137 * before adding snd_dmaengine_pcm_refine_runtime_hwparams 138 * function. 139 */ 140 snd_dmaengine_pcm_refine_runtime_hwparams(substream, 141 dma_data, 142 &hw, 143 chan); 144 145 return snd_soc_set_runtime_hwparams(substream, &hw); 146 } 147 148 static int dmaengine_pcm_open(struct snd_soc_component *component, 149 struct snd_pcm_substream *substream) 150 { 151 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 152 struct dma_chan *chan = pcm->chan[substream->stream]; 153 int ret; 154 155 ret = dmaengine_pcm_set_runtime_hwparams(component, substream); 156 if (ret) 157 return ret; 158 159 return snd_dmaengine_pcm_open(substream, chan); 160 } 161 162 static int dmaengine_pcm_close(struct snd_soc_component *component, 163 struct snd_pcm_substream *substream) 164 { 165 return snd_dmaengine_pcm_close(substream); 166 } 167 168 static int dmaengine_pcm_trigger(struct snd_soc_component *component, 169 struct snd_pcm_substream *substream, int cmd) 170 { 171 return snd_dmaengine_pcm_trigger(substream, cmd); 172 } 173 174 static struct dma_chan *dmaengine_pcm_compat_request_channel( 175 struct snd_soc_component *component, 176 struct snd_soc_pcm_runtime *rtd, 177 struct snd_pcm_substream *substream) 178 { 179 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 180 struct snd_dmaengine_dai_dma_data *dma_data; 181 182 if (rtd->dai_link->num_cpus > 1) { 183 dev_err(rtd->dev, 184 "%s doesn't support Multi CPU yet\n", __func__); 185 return NULL; 186 } 187 188 dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), 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->compat_request_channel) 194 return pcm->config->compat_request_channel(rtd, substream); 195 196 return snd_dmaengine_pcm_request_channel(pcm->config->compat_filter_fn, 197 dma_data->filter_data); 198 } 199 200 static bool dmaengine_pcm_can_report_residue(struct device *dev, 201 struct dma_chan *chan) 202 { 203 struct dma_slave_caps dma_caps; 204 int ret; 205 206 ret = dma_get_slave_caps(chan, &dma_caps); 207 if (ret != 0) { 208 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n", 209 ret); 210 return false; 211 } 212 213 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) 214 return false; 215 216 return true; 217 } 218 219 static int dmaengine_pcm_new(struct snd_soc_component *component, 220 struct snd_soc_pcm_runtime *rtd) 221 { 222 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 223 const struct snd_dmaengine_pcm_config *config = pcm->config; 224 struct device *dev = component->dev; 225 size_t prealloc_buffer_size; 226 size_t max_buffer_size; 227 unsigned int i; 228 229 if (config->prealloc_buffer_size) 230 prealloc_buffer_size = config->prealloc_buffer_size; 231 else 232 prealloc_buffer_size = prealloc_buffer_size_kbytes * 1024; 233 234 if (config->pcm_hardware && config->pcm_hardware->buffer_bytes_max) 235 max_buffer_size = config->pcm_hardware->buffer_bytes_max; 236 else 237 max_buffer_size = SIZE_MAX; 238 239 for_each_pcm_streams(i) { 240 struct snd_pcm_substream *substream = rtd->pcm->streams[i].substream; 241 if (!substream) 242 continue; 243 244 if (!pcm->chan[i] && config->chan_names[i]) 245 pcm->chan[i] = dma_request_slave_channel(dev, 246 config->chan_names[i]); 247 248 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) { 249 pcm->chan[i] = dmaengine_pcm_compat_request_channel( 250 component, rtd, substream); 251 } 252 253 if (!pcm->chan[i]) { 254 dev_err(component->dev, 255 "Missing dma channel for stream: %d\n", i); 256 return -EINVAL; 257 } 258 259 snd_pcm_set_managed_buffer(substream, 260 SNDRV_DMA_TYPE_DEV_IRAM, 261 dmaengine_dma_dev(pcm, substream), 262 prealloc_buffer_size, 263 max_buffer_size); 264 265 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i])) 266 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE; 267 268 if (rtd->pcm->streams[i].pcm->name[0] == '\0') { 269 strscpy_pad(rtd->pcm->streams[i].pcm->name, 270 rtd->pcm->streams[i].pcm->id, 271 sizeof(rtd->pcm->streams[i].pcm->name)); 272 } 273 } 274 275 return 0; 276 } 277 278 static snd_pcm_uframes_t dmaengine_pcm_pointer( 279 struct snd_soc_component *component, 280 struct snd_pcm_substream *substream) 281 { 282 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 283 284 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 285 return snd_dmaengine_pcm_pointer_no_residue(substream); 286 else 287 return snd_dmaengine_pcm_pointer(substream); 288 } 289 290 static int dmaengine_copy_user(struct snd_soc_component *component, 291 struct snd_pcm_substream *substream, 292 int channel, unsigned long hwoff, 293 void __user *buf, unsigned long bytes) 294 { 295 struct snd_pcm_runtime *runtime = substream->runtime; 296 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 297 int (*process)(struct snd_pcm_substream *substream, 298 int channel, unsigned long hwoff, 299 void *buf, unsigned long bytes) = pcm->config->process; 300 bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; 301 void *dma_ptr = runtime->dma_area + hwoff + 302 channel * (runtime->dma_bytes / runtime->channels); 303 304 if (is_playback) 305 if (copy_from_user(dma_ptr, buf, bytes)) 306 return -EFAULT; 307 308 if (process) { 309 int ret = process(substream, channel, hwoff, (__force void *)buf, bytes); 310 if (ret < 0) 311 return ret; 312 } 313 314 if (!is_playback) 315 if (copy_to_user(buf, dma_ptr, bytes)) 316 return -EFAULT; 317 318 return 0; 319 } 320 321 static const struct snd_soc_component_driver dmaengine_pcm_component = { 322 .name = SND_DMAENGINE_PCM_DRV_NAME, 323 .probe_order = SND_SOC_COMP_ORDER_LATE, 324 .open = dmaengine_pcm_open, 325 .close = dmaengine_pcm_close, 326 .hw_params = dmaengine_pcm_hw_params, 327 .trigger = dmaengine_pcm_trigger, 328 .pointer = dmaengine_pcm_pointer, 329 .pcm_construct = dmaengine_pcm_new, 330 }; 331 332 static const struct snd_soc_component_driver dmaengine_pcm_component_process = { 333 .name = SND_DMAENGINE_PCM_DRV_NAME, 334 .probe_order = SND_SOC_COMP_ORDER_LATE, 335 .open = dmaengine_pcm_open, 336 .close = dmaengine_pcm_close, 337 .hw_params = dmaengine_pcm_hw_params, 338 .trigger = dmaengine_pcm_trigger, 339 .pointer = dmaengine_pcm_pointer, 340 .copy_user = dmaengine_copy_user, 341 .pcm_construct = dmaengine_pcm_new, 342 }; 343 344 static const char * const dmaengine_pcm_dma_channel_names[] = { 345 [SNDRV_PCM_STREAM_PLAYBACK] = "tx", 346 [SNDRV_PCM_STREAM_CAPTURE] = "rx", 347 }; 348 349 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, 350 struct device *dev, const struct snd_dmaengine_pcm_config *config) 351 { 352 unsigned int i; 353 const char *name; 354 struct dma_chan *chan; 355 356 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node && 357 !(config->dma_dev && config->dma_dev->of_node))) 358 return 0; 359 360 if (config->dma_dev) { 361 /* 362 * If this warning is seen, it probably means that your Linux 363 * device structure does not match your HW device structure. 364 * It would be best to refactor the Linux device structure to 365 * correctly match the HW structure. 366 */ 367 dev_warn(dev, "DMA channels sourced from device %s", 368 dev_name(config->dma_dev)); 369 dev = config->dma_dev; 370 } 371 372 for_each_pcm_streams(i) { 373 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 374 name = "rx-tx"; 375 else 376 name = dmaengine_pcm_dma_channel_names[i]; 377 if (config->chan_names[i]) 378 name = config->chan_names[i]; 379 chan = dma_request_chan(dev, name); 380 if (IS_ERR(chan)) { 381 /* 382 * Only report probe deferral errors, channels 383 * might not be present for devices that 384 * support only TX or only RX. 385 */ 386 if (PTR_ERR(chan) == -EPROBE_DEFER) 387 return -EPROBE_DEFER; 388 pcm->chan[i] = NULL; 389 } else { 390 pcm->chan[i] = chan; 391 } 392 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 393 break; 394 } 395 396 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 397 pcm->chan[1] = pcm->chan[0]; 398 399 return 0; 400 } 401 402 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) 403 { 404 unsigned int i; 405 406 for_each_pcm_streams(i) { 407 if (!pcm->chan[i]) 408 continue; 409 dma_release_channel(pcm->chan[i]); 410 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 411 break; 412 } 413 } 414 415 static const struct snd_dmaengine_pcm_config snd_dmaengine_pcm_default_config = { 416 .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config, 417 }; 418 419 /** 420 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device 421 * @dev: The parent device for the PCM device 422 * @config: Platform specific PCM configuration 423 * @flags: Platform specific quirks 424 */ 425 int snd_dmaengine_pcm_register(struct device *dev, 426 const struct snd_dmaengine_pcm_config *config, unsigned int flags) 427 { 428 const struct snd_soc_component_driver *driver; 429 struct dmaengine_pcm *pcm; 430 int ret; 431 432 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); 433 if (!pcm) 434 return -ENOMEM; 435 436 #ifdef CONFIG_DEBUG_FS 437 pcm->component.debugfs_prefix = "dma"; 438 #endif 439 if (!config) 440 config = &snd_dmaengine_pcm_default_config; 441 pcm->config = config; 442 pcm->flags = flags; 443 444 ret = dmaengine_pcm_request_chan_of(pcm, dev, config); 445 if (ret) 446 goto err_free_dma; 447 448 if (config->process) 449 driver = &dmaengine_pcm_component_process; 450 else 451 driver = &dmaengine_pcm_component; 452 453 ret = snd_soc_component_initialize(&pcm->component, driver, dev); 454 if (ret) 455 goto err_free_dma; 456 457 ret = snd_soc_add_component(&pcm->component, NULL, 0); 458 if (ret) 459 goto err_free_dma; 460 461 return 0; 462 463 err_free_dma: 464 dmaengine_pcm_release_chan(pcm); 465 kfree(pcm); 466 return ret; 467 } 468 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); 469 470 /** 471 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device 472 * @dev: Parent device the PCM was register with 473 * 474 * Removes a dmaengine based PCM device previously registered with 475 * snd_dmaengine_pcm_register. 476 */ 477 void snd_dmaengine_pcm_unregister(struct device *dev) 478 { 479 struct snd_soc_component *component; 480 struct dmaengine_pcm *pcm; 481 482 component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME); 483 if (!component) 484 return; 485 486 pcm = soc_component_to_pcm(component); 487 488 snd_soc_unregister_component_by_driver(dev, component->driver); 489 dmaengine_pcm_release_chan(pcm); 490 kfree(pcm); 491 } 492 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); 493 494 MODULE_LICENSE("GPL"); 495