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 struct dmaengine_pcm { 28 struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1]; 29 const struct snd_dmaengine_pcm_config *config; 30 struct snd_soc_platform platform; 31 unsigned int flags; 32 }; 33 34 static struct dmaengine_pcm *soc_platform_to_pcm(struct snd_soc_platform *p) 35 { 36 return container_of(p, struct dmaengine_pcm, platform); 37 } 38 39 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm, 40 struct snd_pcm_substream *substream) 41 { 42 if (!pcm->chan[substream->stream]) 43 return NULL; 44 45 return pcm->chan[substream->stream]->device->dev; 46 } 47 48 /** 49 * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback 50 * @substream: PCM substream 51 * @params: hw_params 52 * @slave_config: DMA slave config to prepare 53 * 54 * This function can be used as a generic prepare_slave_config callback for 55 * platforms which make use of the snd_dmaengine_dai_dma_data struct for their 56 * DAI DMA data. Internally the function will first call 57 * snd_hwparams_to_dma_slave_config to fill in the slave config based on the 58 * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the 59 * remaining fields based on the DAI DMA data. 60 */ 61 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream, 62 struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config) 63 { 64 struct snd_soc_pcm_runtime *rtd = substream->private_data; 65 struct snd_dmaengine_dai_dma_data *dma_data; 66 int ret; 67 68 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 69 70 ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config); 71 if (ret) 72 return ret; 73 74 snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data, 75 slave_config); 76 77 return 0; 78 } 79 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config); 80 81 static int dmaengine_pcm_hw_params(struct snd_pcm_substream *substream, 82 struct snd_pcm_hw_params *params) 83 { 84 struct snd_soc_pcm_runtime *rtd = substream->private_data; 85 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 86 struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream); 87 int (*prepare_slave_config)(struct snd_pcm_substream *substream, 88 struct snd_pcm_hw_params *params, 89 struct dma_slave_config *slave_config); 90 struct dma_slave_config slave_config; 91 int ret; 92 93 memset(&slave_config, 0, sizeof(slave_config)); 94 95 if (!pcm->config) 96 prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config; 97 else 98 prepare_slave_config = pcm->config->prepare_slave_config; 99 100 if (prepare_slave_config) { 101 ret = prepare_slave_config(substream, params, &slave_config); 102 if (ret) 103 return ret; 104 105 ret = dmaengine_slave_config(chan, &slave_config); 106 if (ret) 107 return ret; 108 } 109 110 return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params)); 111 } 112 113 static int dmaengine_pcm_set_runtime_hwparams(struct snd_pcm_substream *substream) 114 { 115 struct snd_soc_pcm_runtime *rtd = substream->private_data; 116 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 117 struct device *dma_dev = dmaengine_dma_dev(pcm, substream); 118 struct dma_chan *chan = pcm->chan[substream->stream]; 119 struct snd_dmaengine_dai_dma_data *dma_data; 120 struct dma_slave_caps dma_caps; 121 struct snd_pcm_hardware hw; 122 u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | 123 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | 124 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); 125 int i, ret; 126 127 if (pcm->config && pcm->config->pcm_hardware) 128 return snd_soc_set_runtime_hwparams(substream, 129 pcm->config->pcm_hardware); 130 131 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 132 133 memset(&hw, 0, sizeof(hw)); 134 hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | 135 SNDRV_PCM_INFO_INTERLEAVED; 136 hw.periods_min = 2; 137 hw.periods_max = UINT_MAX; 138 hw.period_bytes_min = 256; 139 hw.period_bytes_max = dma_get_max_seg_size(dma_dev); 140 hw.buffer_bytes_max = SIZE_MAX; 141 hw.fifo_size = dma_data->fifo_size; 142 143 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 144 hw.info |= SNDRV_PCM_INFO_BATCH; 145 146 ret = dma_get_slave_caps(chan, &dma_caps); 147 if (ret == 0) { 148 if (dma_caps.cmd_pause) 149 hw.info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME; 150 if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT) 151 hw.info |= SNDRV_PCM_INFO_BATCH; 152 153 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) 154 addr_widths = dma_caps.dstn_addr_widths; 155 else 156 addr_widths = dma_caps.src_addr_widths; 157 } 158 159 /* 160 * Prepare formats mask for valid/allowed sample types. If the dma does 161 * not have support for the given physical word size, it needs to be 162 * masked out so user space can not use the format which produces 163 * corrupted audio. 164 * In case the dma driver does not implement the slave_caps the default 165 * assumption is that it supports 1, 2 and 4 bytes widths. 166 */ 167 for (i = 0; i <= SNDRV_PCM_FORMAT_LAST; i++) { 168 int bits = snd_pcm_format_physical_width(i); 169 170 /* Enable only samples with DMA supported physical widths */ 171 switch (bits) { 172 case 8: 173 case 16: 174 case 24: 175 case 32: 176 case 64: 177 if (addr_widths & (1 << (bits / 8))) 178 hw.formats |= (1LL << i); 179 break; 180 default: 181 /* Unsupported types */ 182 break; 183 } 184 } 185 186 return snd_soc_set_runtime_hwparams(substream, &hw); 187 } 188 189 static int dmaengine_pcm_open(struct snd_pcm_substream *substream) 190 { 191 struct snd_soc_pcm_runtime *rtd = substream->private_data; 192 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 193 struct dma_chan *chan = pcm->chan[substream->stream]; 194 int ret; 195 196 ret = dmaengine_pcm_set_runtime_hwparams(substream); 197 if (ret) 198 return ret; 199 200 return snd_dmaengine_pcm_open(substream, chan); 201 } 202 203 static void dmaengine_pcm_free(struct snd_pcm *pcm) 204 { 205 snd_pcm_lib_preallocate_free_for_all(pcm); 206 } 207 208 static struct dma_chan *dmaengine_pcm_compat_request_channel( 209 struct snd_soc_pcm_runtime *rtd, 210 struct snd_pcm_substream *substream) 211 { 212 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 213 struct snd_dmaengine_dai_dma_data *dma_data; 214 dma_filter_fn fn = NULL; 215 216 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 217 218 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0]) 219 return pcm->chan[0]; 220 221 if (pcm->config && pcm->config->compat_request_channel) 222 return pcm->config->compat_request_channel(rtd, substream); 223 224 if (pcm->config) 225 fn = pcm->config->compat_filter_fn; 226 227 return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data); 228 } 229 230 static bool dmaengine_pcm_can_report_residue(struct dma_chan *chan) 231 { 232 struct dma_slave_caps dma_caps; 233 int ret; 234 235 ret = dma_get_slave_caps(chan, &dma_caps); 236 if (ret != 0) 237 return true; 238 239 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) 240 return false; 241 242 return true; 243 } 244 245 static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd) 246 { 247 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 248 const struct snd_dmaengine_pcm_config *config = pcm->config; 249 struct device *dev = rtd->platform->dev; 250 struct snd_dmaengine_dai_dma_data *dma_data; 251 struct snd_pcm_substream *substream; 252 size_t prealloc_buffer_size; 253 size_t max_buffer_size; 254 unsigned int i; 255 int ret; 256 257 if (config && config->prealloc_buffer_size) { 258 prealloc_buffer_size = config->prealloc_buffer_size; 259 max_buffer_size = config->pcm_hardware->buffer_bytes_max; 260 } else { 261 prealloc_buffer_size = 512 * 1024; 262 max_buffer_size = SIZE_MAX; 263 } 264 265 266 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { 267 substream = rtd->pcm->streams[i].substream; 268 if (!substream) 269 continue; 270 271 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 272 273 if (!pcm->chan[i] && 274 (pcm->flags & SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) 275 pcm->chan[i] = dma_request_slave_channel(dev, 276 dma_data->chan_name); 277 278 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) { 279 pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd, 280 substream); 281 } 282 283 if (!pcm->chan[i]) { 284 dev_err(rtd->platform->dev, 285 "Missing dma channel for stream: %d\n", i); 286 ret = -EINVAL; 287 goto err_free; 288 } 289 290 ret = snd_pcm_lib_preallocate_pages(substream, 291 SNDRV_DMA_TYPE_DEV_IRAM, 292 dmaengine_dma_dev(pcm, substream), 293 prealloc_buffer_size, 294 max_buffer_size); 295 if (ret) 296 goto err_free; 297 298 /* 299 * This will only return false if we know for sure that at least 300 * one channel does not support residue reporting. If the DMA 301 * driver does not implement the slave_caps API we rely having 302 * the NO_RESIDUE flag set manually in case residue reporting is 303 * not supported. 304 */ 305 if (!dmaengine_pcm_can_report_residue(pcm->chan[i])) 306 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE; 307 } 308 309 return 0; 310 311 err_free: 312 dmaengine_pcm_free(rtd->pcm); 313 return ret; 314 } 315 316 static snd_pcm_uframes_t dmaengine_pcm_pointer( 317 struct snd_pcm_substream *substream) 318 { 319 struct snd_soc_pcm_runtime *rtd = substream->private_data; 320 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 321 322 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 323 return snd_dmaengine_pcm_pointer_no_residue(substream); 324 else 325 return snd_dmaengine_pcm_pointer(substream); 326 } 327 328 static const struct snd_pcm_ops dmaengine_pcm_ops = { 329 .open = dmaengine_pcm_open, 330 .close = snd_dmaengine_pcm_close, 331 .ioctl = snd_pcm_lib_ioctl, 332 .hw_params = dmaengine_pcm_hw_params, 333 .hw_free = snd_pcm_lib_free_pages, 334 .trigger = snd_dmaengine_pcm_trigger, 335 .pointer = dmaengine_pcm_pointer, 336 }; 337 338 static const struct snd_soc_platform_driver dmaengine_pcm_platform = { 339 .ops = &dmaengine_pcm_ops, 340 .pcm_new = dmaengine_pcm_new, 341 .pcm_free = dmaengine_pcm_free, 342 .probe_order = SND_SOC_COMP_ORDER_LATE, 343 }; 344 345 static const char * const dmaengine_pcm_dma_channel_names[] = { 346 [SNDRV_PCM_STREAM_PLAYBACK] = "tx", 347 [SNDRV_PCM_STREAM_CAPTURE] = "rx", 348 }; 349 350 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, 351 struct device *dev, const struct snd_dmaengine_pcm_config *config) 352 { 353 unsigned int i; 354 const char *name; 355 struct dma_chan *chan; 356 357 if ((pcm->flags & (SND_DMAENGINE_PCM_FLAG_NO_DT | 358 SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) || 359 !dev->of_node) 360 return 0; 361 362 if (config && config->dma_dev) { 363 /* 364 * If this warning is seen, it probably means that your Linux 365 * device structure does not match your HW device structure. 366 * It would be best to refactor the Linux device structure to 367 * correctly match the HW structure. 368 */ 369 dev_warn(dev, "DMA channels sourced from device %s", 370 dev_name(config->dma_dev)); 371 dev = config->dma_dev; 372 } 373 374 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 375 i++) { 376 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 377 name = "rx-tx"; 378 else 379 name = dmaengine_pcm_dma_channel_names[i]; 380 if (config && config->chan_names[i]) 381 name = config->chan_names[i]; 382 chan = dma_request_slave_channel_reason(dev, name); 383 if (IS_ERR(chan)) { 384 if (PTR_ERR(chan) == -EPROBE_DEFER) 385 return -EPROBE_DEFER; 386 pcm->chan[i] = NULL; 387 } else { 388 pcm->chan[i] = chan; 389 } 390 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 391 break; 392 } 393 394 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 395 pcm->chan[1] = pcm->chan[0]; 396 397 return 0; 398 } 399 400 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) 401 { 402 unsigned int i; 403 404 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 405 i++) { 406 if (!pcm->chan[i]) 407 continue; 408 dma_release_channel(pcm->chan[i]); 409 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 410 break; 411 } 412 } 413 414 /** 415 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device 416 * @dev: The parent device for the PCM device 417 * @config: Platform specific PCM configuration 418 * @flags: Platform specific quirks 419 */ 420 int snd_dmaengine_pcm_register(struct device *dev, 421 const struct snd_dmaengine_pcm_config *config, unsigned int flags) 422 { 423 struct dmaengine_pcm *pcm; 424 int ret; 425 426 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); 427 if (!pcm) 428 return -ENOMEM; 429 430 pcm->config = config; 431 pcm->flags = flags; 432 433 ret = dmaengine_pcm_request_chan_of(pcm, dev, config); 434 if (ret) 435 goto err_free_dma; 436 437 ret = snd_soc_add_platform(dev, &pcm->platform, 438 &dmaengine_pcm_platform); 439 if (ret) 440 goto err_free_dma; 441 442 return 0; 443 444 err_free_dma: 445 dmaengine_pcm_release_chan(pcm); 446 kfree(pcm); 447 return ret; 448 } 449 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); 450 451 /** 452 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device 453 * @dev: Parent device the PCM was register with 454 * 455 * Removes a dmaengine based PCM device previously registered with 456 * snd_dmaengine_pcm_register. 457 */ 458 void snd_dmaengine_pcm_unregister(struct device *dev) 459 { 460 struct snd_soc_platform *platform; 461 struct dmaengine_pcm *pcm; 462 463 platform = snd_soc_lookup_platform(dev); 464 if (!platform) 465 return; 466 467 pcm = soc_platform_to_pcm(platform); 468 469 snd_soc_remove_platform(platform); 470 dmaengine_pcm_release_chan(pcm); 471 kfree(pcm); 472 } 473 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); 474 475 MODULE_LICENSE("GPL"); 476