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 && pcm->config->prepare_slave_config) 90 prepare_slave_config = pcm->config->prepare_slave_config; 91 else 92 prepare_slave_config = snd_dmaengine_pcm_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 = dma_data->maxburst * DMA_SLAVE_BUSWIDTH_8_BYTES; 136 if (!hw.period_bytes_min) 137 hw.period_bytes_min = 256; 138 hw.period_bytes_max = dma_get_max_seg_size(dma_dev); 139 hw.buffer_bytes_max = SIZE_MAX; 140 hw.fifo_size = dma_data->fifo_size; 141 142 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 143 hw.info |= SNDRV_PCM_INFO_BATCH; 144 145 /** 146 * FIXME: Remove the return value check to align with the code 147 * before adding snd_dmaengine_pcm_refine_runtime_hwparams 148 * function. 149 */ 150 snd_dmaengine_pcm_refine_runtime_hwparams(substream, 151 dma_data, 152 &hw, 153 chan); 154 155 return snd_soc_set_runtime_hwparams(substream, &hw); 156 } 157 158 static int dmaengine_pcm_open(struct snd_soc_component *component, 159 struct snd_pcm_substream *substream) 160 { 161 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 162 struct dma_chan *chan = pcm->chan[substream->stream]; 163 int ret; 164 165 ret = dmaengine_pcm_set_runtime_hwparams(component, substream); 166 if (ret) 167 return ret; 168 169 return snd_dmaengine_pcm_open(substream, chan); 170 } 171 172 static int dmaengine_pcm_close(struct snd_soc_component *component, 173 struct snd_pcm_substream *substream) 174 { 175 return snd_dmaengine_pcm_close(substream); 176 } 177 178 static int dmaengine_pcm_trigger(struct snd_soc_component *component, 179 struct snd_pcm_substream *substream, int cmd) 180 { 181 return snd_dmaengine_pcm_trigger(substream, cmd); 182 } 183 184 static struct dma_chan *dmaengine_pcm_compat_request_channel( 185 struct snd_soc_component *component, 186 struct snd_soc_pcm_runtime *rtd, 187 struct snd_pcm_substream *substream) 188 { 189 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 190 struct snd_dmaengine_dai_dma_data *dma_data; 191 dma_filter_fn fn = NULL; 192 193 if (rtd->num_cpus > 1) { 194 dev_err(rtd->dev, 195 "%s doesn't support Multi CPU yet\n", __func__); 196 return NULL; 197 } 198 199 dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream); 200 201 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0]) 202 return pcm->chan[0]; 203 204 if (pcm->config && pcm->config->compat_request_channel) 205 return pcm->config->compat_request_channel(rtd, substream); 206 207 if (pcm->config) 208 fn = pcm->config->compat_filter_fn; 209 210 return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data); 211 } 212 213 static bool dmaengine_pcm_can_report_residue(struct device *dev, 214 struct dma_chan *chan) 215 { 216 struct dma_slave_caps dma_caps; 217 int ret; 218 219 ret = dma_get_slave_caps(chan, &dma_caps); 220 if (ret != 0) { 221 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n", 222 ret); 223 return false; 224 } 225 226 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) 227 return false; 228 229 return true; 230 } 231 232 static int dmaengine_pcm_new(struct snd_soc_component *component, 233 struct snd_soc_pcm_runtime *rtd) 234 { 235 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 236 const struct snd_dmaengine_pcm_config *config = pcm->config; 237 struct device *dev = component->dev; 238 size_t prealloc_buffer_size; 239 size_t max_buffer_size; 240 unsigned int i; 241 242 if (config && config->prealloc_buffer_size) 243 prealloc_buffer_size = config->prealloc_buffer_size; 244 else 245 prealloc_buffer_size = prealloc_buffer_size_kbytes * 1024; 246 247 if (config && config->pcm_hardware && config->pcm_hardware->buffer_bytes_max) 248 max_buffer_size = config->pcm_hardware->buffer_bytes_max; 249 else 250 max_buffer_size = SIZE_MAX; 251 252 for_each_pcm_streams(i) { 253 struct snd_pcm_substream *substream = rtd->pcm->streams[i].substream; 254 if (!substream) 255 continue; 256 257 if (!pcm->chan[i] && config && config->chan_names[i]) 258 pcm->chan[i] = dma_request_slave_channel(dev, 259 config->chan_names[i]); 260 261 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) { 262 pcm->chan[i] = dmaengine_pcm_compat_request_channel( 263 component, rtd, substream); 264 } 265 266 if (!pcm->chan[i]) { 267 dev_err(component->dev, 268 "Missing dma channel for stream: %d\n", i); 269 return -EINVAL; 270 } 271 272 snd_pcm_set_managed_buffer(substream, 273 SNDRV_DMA_TYPE_DEV_IRAM, 274 dmaengine_dma_dev(pcm, substream), 275 prealloc_buffer_size, 276 max_buffer_size); 277 278 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i])) 279 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE; 280 281 if (rtd->pcm->streams[i].pcm->name[0] == '\0') { 282 strscpy_pad(rtd->pcm->streams[i].pcm->name, 283 rtd->pcm->streams[i].pcm->id, 284 sizeof(rtd->pcm->streams[i].pcm->name)); 285 } 286 } 287 288 return 0; 289 } 290 291 static snd_pcm_uframes_t dmaengine_pcm_pointer( 292 struct snd_soc_component *component, 293 struct snd_pcm_substream *substream) 294 { 295 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 296 297 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 298 return snd_dmaengine_pcm_pointer_no_residue(substream); 299 else 300 return snd_dmaengine_pcm_pointer(substream); 301 } 302 303 static int dmaengine_copy_user(struct snd_soc_component *component, 304 struct snd_pcm_substream *substream, 305 int channel, unsigned long hwoff, 306 void __user *buf, unsigned long bytes) 307 { 308 struct snd_pcm_runtime *runtime = substream->runtime; 309 struct dmaengine_pcm *pcm = soc_component_to_pcm(component); 310 int (*process)(struct snd_pcm_substream *substream, 311 int channel, unsigned long hwoff, 312 void *buf, unsigned long bytes) = pcm->config->process; 313 bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; 314 void *dma_ptr = runtime->dma_area + hwoff + 315 channel * (runtime->dma_bytes / runtime->channels); 316 317 if (is_playback) 318 if (copy_from_user(dma_ptr, buf, bytes)) 319 return -EFAULT; 320 321 if (process) { 322 int ret = process(substream, channel, hwoff, (__force void *)buf, bytes); 323 if (ret < 0) 324 return ret; 325 } 326 327 if (!is_playback) 328 if (copy_to_user(buf, dma_ptr, bytes)) 329 return -EFAULT; 330 331 return 0; 332 } 333 334 static const struct snd_soc_component_driver dmaengine_pcm_component = { 335 .name = SND_DMAENGINE_PCM_DRV_NAME, 336 .probe_order = SND_SOC_COMP_ORDER_LATE, 337 .open = dmaengine_pcm_open, 338 .close = dmaengine_pcm_close, 339 .hw_params = dmaengine_pcm_hw_params, 340 .trigger = dmaengine_pcm_trigger, 341 .pointer = dmaengine_pcm_pointer, 342 .pcm_construct = dmaengine_pcm_new, 343 }; 344 345 static const struct snd_soc_component_driver dmaengine_pcm_component_process = { 346 .name = SND_DMAENGINE_PCM_DRV_NAME, 347 .probe_order = SND_SOC_COMP_ORDER_LATE, 348 .open = dmaengine_pcm_open, 349 .close = dmaengine_pcm_close, 350 .hw_params = dmaengine_pcm_hw_params, 351 .trigger = dmaengine_pcm_trigger, 352 .pointer = dmaengine_pcm_pointer, 353 .copy_user = dmaengine_copy_user, 354 .pcm_construct = dmaengine_pcm_new, 355 }; 356 357 static const char * const dmaengine_pcm_dma_channel_names[] = { 358 [SNDRV_PCM_STREAM_PLAYBACK] = "tx", 359 [SNDRV_PCM_STREAM_CAPTURE] = "rx", 360 }; 361 362 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, 363 struct device *dev, const struct snd_dmaengine_pcm_config *config) 364 { 365 unsigned int i; 366 const char *name; 367 struct dma_chan *chan; 368 369 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node && 370 !(config && config->dma_dev && config->dma_dev->of_node))) 371 return 0; 372 373 if (config && config->dma_dev) { 374 /* 375 * If this warning is seen, it probably means that your Linux 376 * device structure does not match your HW device structure. 377 * It would be best to refactor the Linux device structure to 378 * correctly match the HW structure. 379 */ 380 dev_warn(dev, "DMA channels sourced from device %s", 381 dev_name(config->dma_dev)); 382 dev = config->dma_dev; 383 } 384 385 for_each_pcm_streams(i) { 386 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 387 name = "rx-tx"; 388 else 389 name = dmaengine_pcm_dma_channel_names[i]; 390 if (config && config->chan_names[i]) 391 name = config->chan_names[i]; 392 chan = dma_request_chan(dev, name); 393 if (IS_ERR(chan)) { 394 /* 395 * Only report probe deferral errors, channels 396 * might not be present for devices that 397 * support only TX or only RX. 398 */ 399 if (PTR_ERR(chan) == -EPROBE_DEFER) 400 return -EPROBE_DEFER; 401 pcm->chan[i] = NULL; 402 } else { 403 pcm->chan[i] = chan; 404 } 405 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 406 break; 407 } 408 409 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 410 pcm->chan[1] = pcm->chan[0]; 411 412 return 0; 413 } 414 415 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) 416 { 417 unsigned int i; 418 419 for_each_pcm_streams(i) { 420 if (!pcm->chan[i]) 421 continue; 422 dma_release_channel(pcm->chan[i]); 423 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 424 break; 425 } 426 } 427 428 /** 429 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device 430 * @dev: The parent device for the PCM device 431 * @config: Platform specific PCM configuration 432 * @flags: Platform specific quirks 433 */ 434 int snd_dmaengine_pcm_register(struct device *dev, 435 const struct snd_dmaengine_pcm_config *config, unsigned int flags) 436 { 437 const struct snd_soc_component_driver *driver; 438 struct dmaengine_pcm *pcm; 439 int ret; 440 441 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); 442 if (!pcm) 443 return -ENOMEM; 444 445 #ifdef CONFIG_DEBUG_FS 446 pcm->component.debugfs_prefix = "dma"; 447 #endif 448 pcm->config = config; 449 pcm->flags = flags; 450 451 ret = dmaengine_pcm_request_chan_of(pcm, dev, config); 452 if (ret) 453 goto err_free_dma; 454 455 if (config && config->process) 456 driver = &dmaengine_pcm_component_process; 457 else 458 driver = &dmaengine_pcm_component; 459 460 ret = snd_soc_component_initialize(&pcm->component, driver, dev); 461 if (ret) 462 goto err_free_dma; 463 464 ret = snd_soc_add_component(&pcm->component, NULL, 0); 465 if (ret) 466 goto err_free_dma; 467 468 return 0; 469 470 err_free_dma: 471 dmaengine_pcm_release_chan(pcm); 472 kfree(pcm); 473 return ret; 474 } 475 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); 476 477 /** 478 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device 479 * @dev: Parent device the PCM was register with 480 * 481 * Removes a dmaengine based PCM device previously registered with 482 * snd_dmaengine_pcm_register. 483 */ 484 void snd_dmaengine_pcm_unregister(struct device *dev) 485 { 486 struct snd_soc_component *component; 487 struct dmaengine_pcm *pcm; 488 489 component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME); 490 if (!component) 491 return; 492 493 pcm = soc_component_to_pcm(component); 494 495 snd_soc_unregister_component_by_driver(dev, component->driver); 496 dmaengine_pcm_release_chan(pcm); 497 kfree(pcm); 498 } 499 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); 500 501 MODULE_LICENSE("GPL"); 502