1 /* 2 * Copyright (C) 2013, Analog Devices Inc. 3 * Author: Lars-Peter Clausen <lars@metafoo.de> 4 * 5 * This program is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License as published by the 7 * Free Software Foundation; either version 2 of the License, or (at your 8 * option) any later version. 9 * 10 * You should have received a copy of the GNU General Public License along 11 * with this program; if not, write to the Free Software Foundation, Inc., 12 * 675 Mass Ave, Cambridge, MA 02139, USA. 13 * 14 */ 15 #include <linux/module.h> 16 #include <linux/init.h> 17 #include <linux/dmaengine.h> 18 #include <linux/slab.h> 19 #include <sound/pcm.h> 20 #include <sound/pcm_params.h> 21 #include <sound/soc.h> 22 #include <linux/dma-mapping.h> 23 #include <linux/of.h> 24 25 #include <sound/dmaengine_pcm.h> 26 27 /* 28 * The platforms dmaengine driver does not support reporting the amount of 29 * bytes that are still left to transfer. 30 */ 31 #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31) 32 33 struct dmaengine_pcm { 34 struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1]; 35 const struct snd_dmaengine_pcm_config *config; 36 struct snd_soc_platform platform; 37 unsigned int flags; 38 }; 39 40 static struct dmaengine_pcm *soc_platform_to_pcm(struct snd_soc_platform *p) 41 { 42 return container_of(p, struct dmaengine_pcm, platform); 43 } 44 45 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm, 46 struct snd_pcm_substream *substream) 47 { 48 if (!pcm->chan[substream->stream]) 49 return NULL; 50 51 return pcm->chan[substream->stream]->device->dev; 52 } 53 54 /** 55 * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback 56 * @substream: PCM substream 57 * @params: hw_params 58 * @slave_config: DMA slave config to prepare 59 * 60 * This function can be used as a generic prepare_slave_config callback for 61 * platforms which make use of the snd_dmaengine_dai_dma_data struct for their 62 * DAI DMA data. Internally the function will first call 63 * snd_hwparams_to_dma_slave_config to fill in the slave config based on the 64 * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the 65 * remaining fields based on the DAI DMA data. 66 */ 67 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream, 68 struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config) 69 { 70 struct snd_soc_pcm_runtime *rtd = substream->private_data; 71 struct snd_dmaengine_dai_dma_data *dma_data; 72 int ret; 73 74 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 75 76 ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config); 77 if (ret) 78 return ret; 79 80 snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data, 81 slave_config); 82 83 return 0; 84 } 85 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config); 86 87 static int dmaengine_pcm_hw_params(struct snd_pcm_substream *substream, 88 struct snd_pcm_hw_params *params) 89 { 90 struct snd_soc_pcm_runtime *rtd = substream->private_data; 91 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 92 struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream); 93 int (*prepare_slave_config)(struct snd_pcm_substream *substream, 94 struct snd_pcm_hw_params *params, 95 struct dma_slave_config *slave_config); 96 struct dma_slave_config slave_config; 97 int ret; 98 99 memset(&slave_config, 0, sizeof(slave_config)); 100 101 if (!pcm->config) 102 prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config; 103 else 104 prepare_slave_config = pcm->config->prepare_slave_config; 105 106 if (prepare_slave_config) { 107 ret = prepare_slave_config(substream, params, &slave_config); 108 if (ret) 109 return ret; 110 111 ret = dmaengine_slave_config(chan, &slave_config); 112 if (ret) 113 return ret; 114 } 115 116 return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params)); 117 } 118 119 static int dmaengine_pcm_set_runtime_hwparams(struct snd_pcm_substream *substream) 120 { 121 struct snd_soc_pcm_runtime *rtd = substream->private_data; 122 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 123 struct device *dma_dev = dmaengine_dma_dev(pcm, substream); 124 struct dma_chan *chan = pcm->chan[substream->stream]; 125 struct snd_dmaengine_dai_dma_data *dma_data; 126 struct dma_slave_caps dma_caps; 127 struct snd_pcm_hardware hw; 128 u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | 129 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | 130 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); 131 int i, ret; 132 133 if (pcm->config && pcm->config->pcm_hardware) 134 return snd_soc_set_runtime_hwparams(substream, 135 pcm->config->pcm_hardware); 136 137 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 138 139 memset(&hw, 0, sizeof(hw)); 140 hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | 141 SNDRV_PCM_INFO_INTERLEAVED; 142 hw.periods_min = 2; 143 hw.periods_max = UINT_MAX; 144 hw.period_bytes_min = 256; 145 hw.period_bytes_max = dma_get_max_seg_size(dma_dev); 146 hw.buffer_bytes_max = SIZE_MAX; 147 hw.fifo_size = dma_data->fifo_size; 148 149 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 150 hw.info |= SNDRV_PCM_INFO_BATCH; 151 152 ret = dma_get_slave_caps(chan, &dma_caps); 153 if (ret == 0) { 154 if (dma_caps.cmd_pause) 155 hw.info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME; 156 if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT) 157 hw.info |= SNDRV_PCM_INFO_BATCH; 158 159 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) 160 addr_widths = dma_caps.dst_addr_widths; 161 else 162 addr_widths = dma_caps.src_addr_widths; 163 } 164 165 /* 166 * If SND_DMAENGINE_PCM_DAI_FLAG_PACK is set keep 167 * hw.formats set to 0, meaning no restrictions are in place. 168 * In this case it's the responsibility of the DAI driver to 169 * provide the supported format information. 170 */ 171 if (!(dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)) 172 /* 173 * Prepare formats mask for valid/allowed sample types. If the 174 * dma does not have support for the given physical word size, 175 * it needs to be masked out so user space can not use the 176 * format which produces corrupted audio. 177 * In case the dma driver does not implement the slave_caps the 178 * default assumption is that it supports 1, 2 and 4 bytes 179 * widths. 180 */ 181 for (i = 0; i <= SNDRV_PCM_FORMAT_LAST; i++) { 182 int bits = snd_pcm_format_physical_width(i); 183 184 /* 185 * Enable only samples with DMA supported physical 186 * widths 187 */ 188 switch (bits) { 189 case 8: 190 case 16: 191 case 24: 192 case 32: 193 case 64: 194 if (addr_widths & (1 << (bits / 8))) 195 hw.formats |= (1LL << i); 196 break; 197 default: 198 /* Unsupported types */ 199 break; 200 } 201 } 202 203 return snd_soc_set_runtime_hwparams(substream, &hw); 204 } 205 206 static int dmaengine_pcm_open(struct snd_pcm_substream *substream) 207 { 208 struct snd_soc_pcm_runtime *rtd = substream->private_data; 209 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 210 struct dma_chan *chan = pcm->chan[substream->stream]; 211 int ret; 212 213 ret = dmaengine_pcm_set_runtime_hwparams(substream); 214 if (ret) 215 return ret; 216 217 return snd_dmaengine_pcm_open(substream, chan); 218 } 219 220 static struct dma_chan *dmaengine_pcm_compat_request_channel( 221 struct snd_soc_pcm_runtime *rtd, 222 struct snd_pcm_substream *substream) 223 { 224 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 225 struct snd_dmaengine_dai_dma_data *dma_data; 226 dma_filter_fn fn = NULL; 227 228 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 229 230 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0]) 231 return pcm->chan[0]; 232 233 if (pcm->config && pcm->config->compat_request_channel) 234 return pcm->config->compat_request_channel(rtd, substream); 235 236 if (pcm->config) 237 fn = pcm->config->compat_filter_fn; 238 239 return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data); 240 } 241 242 static bool dmaengine_pcm_can_report_residue(struct device *dev, 243 struct dma_chan *chan) 244 { 245 struct dma_slave_caps dma_caps; 246 int ret; 247 248 ret = dma_get_slave_caps(chan, &dma_caps); 249 if (ret != 0) { 250 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n", 251 ret); 252 return false; 253 } 254 255 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) 256 return false; 257 258 return true; 259 } 260 261 static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd) 262 { 263 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 264 const struct snd_dmaengine_pcm_config *config = pcm->config; 265 struct device *dev = rtd->platform->dev; 266 struct snd_dmaengine_dai_dma_data *dma_data; 267 struct snd_pcm_substream *substream; 268 size_t prealloc_buffer_size; 269 size_t max_buffer_size; 270 unsigned int i; 271 int ret; 272 273 if (config && config->prealloc_buffer_size) { 274 prealloc_buffer_size = config->prealloc_buffer_size; 275 max_buffer_size = config->pcm_hardware->buffer_bytes_max; 276 } else { 277 prealloc_buffer_size = 512 * 1024; 278 max_buffer_size = SIZE_MAX; 279 } 280 281 282 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { 283 substream = rtd->pcm->streams[i].substream; 284 if (!substream) 285 continue; 286 287 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 288 289 if (!pcm->chan[i] && 290 (pcm->flags & SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) 291 pcm->chan[i] = dma_request_slave_channel(dev, 292 dma_data->chan_name); 293 294 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) { 295 pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd, 296 substream); 297 } 298 299 if (!pcm->chan[i]) { 300 dev_err(rtd->platform->dev, 301 "Missing dma channel for stream: %d\n", i); 302 return -EINVAL; 303 } 304 305 ret = snd_pcm_lib_preallocate_pages(substream, 306 SNDRV_DMA_TYPE_DEV_IRAM, 307 dmaengine_dma_dev(pcm, substream), 308 prealloc_buffer_size, 309 max_buffer_size); 310 if (ret) 311 return ret; 312 313 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i])) 314 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE; 315 } 316 317 return 0; 318 } 319 320 static snd_pcm_uframes_t dmaengine_pcm_pointer( 321 struct snd_pcm_substream *substream) 322 { 323 struct snd_soc_pcm_runtime *rtd = substream->private_data; 324 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 325 326 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 327 return snd_dmaengine_pcm_pointer_no_residue(substream); 328 else 329 return snd_dmaengine_pcm_pointer(substream); 330 } 331 332 static const struct snd_pcm_ops dmaengine_pcm_ops = { 333 .open = dmaengine_pcm_open, 334 .close = snd_dmaengine_pcm_close, 335 .ioctl = snd_pcm_lib_ioctl, 336 .hw_params = dmaengine_pcm_hw_params, 337 .hw_free = snd_pcm_lib_free_pages, 338 .trigger = snd_dmaengine_pcm_trigger, 339 .pointer = dmaengine_pcm_pointer, 340 }; 341 342 static const struct snd_soc_platform_driver dmaengine_pcm_platform = { 343 .component_driver = { 344 .probe_order = SND_SOC_COMP_ORDER_LATE, 345 }, 346 .ops = &dmaengine_pcm_ops, 347 .pcm_new = dmaengine_pcm_new, 348 }; 349 350 static const char * const dmaengine_pcm_dma_channel_names[] = { 351 [SNDRV_PCM_STREAM_PLAYBACK] = "tx", 352 [SNDRV_PCM_STREAM_CAPTURE] = "rx", 353 }; 354 355 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, 356 struct device *dev, const struct snd_dmaengine_pcm_config *config) 357 { 358 unsigned int i; 359 const char *name; 360 struct dma_chan *chan; 361 362 if ((pcm->flags & (SND_DMAENGINE_PCM_FLAG_NO_DT | 363 SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) || 364 !dev->of_node) 365 return 0; 366 367 if (config && config->dma_dev) { 368 /* 369 * If this warning is seen, it probably means that your Linux 370 * device structure does not match your HW device structure. 371 * It would be best to refactor the Linux device structure to 372 * correctly match the HW structure. 373 */ 374 dev_warn(dev, "DMA channels sourced from device %s", 375 dev_name(config->dma_dev)); 376 dev = config->dma_dev; 377 } 378 379 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 380 i++) { 381 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 382 name = "rx-tx"; 383 else 384 name = dmaengine_pcm_dma_channel_names[i]; 385 if (config && config->chan_names[i]) 386 name = config->chan_names[i]; 387 chan = dma_request_slave_channel_reason(dev, name); 388 if (IS_ERR(chan)) { 389 if (PTR_ERR(chan) == -EPROBE_DEFER) 390 return -EPROBE_DEFER; 391 pcm->chan[i] = NULL; 392 } else { 393 pcm->chan[i] = chan; 394 } 395 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 396 break; 397 } 398 399 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 400 pcm->chan[1] = pcm->chan[0]; 401 402 return 0; 403 } 404 405 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) 406 { 407 unsigned int i; 408 409 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 410 i++) { 411 if (!pcm->chan[i]) 412 continue; 413 dma_release_channel(pcm->chan[i]); 414 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 415 break; 416 } 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 struct dmaengine_pcm *pcm; 429 int ret; 430 431 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); 432 if (!pcm) 433 return -ENOMEM; 434 435 pcm->config = config; 436 pcm->flags = flags; 437 438 ret = dmaengine_pcm_request_chan_of(pcm, dev, config); 439 if (ret) 440 goto err_free_dma; 441 442 ret = snd_soc_add_platform(dev, &pcm->platform, 443 &dmaengine_pcm_platform); 444 if (ret) 445 goto err_free_dma; 446 447 return 0; 448 449 err_free_dma: 450 dmaengine_pcm_release_chan(pcm); 451 kfree(pcm); 452 return ret; 453 } 454 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); 455 456 /** 457 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device 458 * @dev: Parent device the PCM was register with 459 * 460 * Removes a dmaengine based PCM device previously registered with 461 * snd_dmaengine_pcm_register. 462 */ 463 void snd_dmaengine_pcm_unregister(struct device *dev) 464 { 465 struct snd_soc_platform *platform; 466 struct dmaengine_pcm *pcm; 467 468 platform = snd_soc_lookup_platform(dev); 469 if (!platform) 470 return; 471 472 pcm = soc_platform_to_pcm(platform); 473 474 snd_soc_remove_platform(platform); 475 dmaengine_pcm_release_chan(pcm); 476 kfree(pcm); 477 } 478 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); 479 480 MODULE_LICENSE("GPL"); 481