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