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.dst_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 struct dma_chan *dmaengine_pcm_compat_request_channel( 204 struct snd_soc_pcm_runtime *rtd, 205 struct snd_pcm_substream *substream) 206 { 207 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 208 struct snd_dmaengine_dai_dma_data *dma_data; 209 dma_filter_fn fn = NULL; 210 211 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 212 213 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0]) 214 return pcm->chan[0]; 215 216 if (pcm->config && pcm->config->compat_request_channel) 217 return pcm->config->compat_request_channel(rtd, substream); 218 219 if (pcm->config) 220 fn = pcm->config->compat_filter_fn; 221 222 return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data); 223 } 224 225 static bool dmaengine_pcm_can_report_residue(struct dma_chan *chan) 226 { 227 struct dma_slave_caps dma_caps; 228 int ret; 229 230 ret = dma_get_slave_caps(chan, &dma_caps); 231 if (ret != 0) 232 return true; 233 234 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) 235 return false; 236 237 return true; 238 } 239 240 static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd) 241 { 242 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 243 const struct snd_dmaengine_pcm_config *config = pcm->config; 244 struct device *dev = rtd->platform->dev; 245 struct snd_dmaengine_dai_dma_data *dma_data; 246 struct snd_pcm_substream *substream; 247 size_t prealloc_buffer_size; 248 size_t max_buffer_size; 249 unsigned int i; 250 int ret; 251 252 if (config && config->prealloc_buffer_size) { 253 prealloc_buffer_size = config->prealloc_buffer_size; 254 max_buffer_size = config->pcm_hardware->buffer_bytes_max; 255 } else { 256 prealloc_buffer_size = 512 * 1024; 257 max_buffer_size = SIZE_MAX; 258 } 259 260 261 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { 262 substream = rtd->pcm->streams[i].substream; 263 if (!substream) 264 continue; 265 266 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 267 268 if (!pcm->chan[i] && 269 (pcm->flags & SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) 270 pcm->chan[i] = dma_request_slave_channel(dev, 271 dma_data->chan_name); 272 273 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) { 274 pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd, 275 substream); 276 } 277 278 if (!pcm->chan[i]) { 279 dev_err(rtd->platform->dev, 280 "Missing dma channel for stream: %d\n", i); 281 return -EINVAL; 282 } 283 284 ret = snd_pcm_lib_preallocate_pages(substream, 285 SNDRV_DMA_TYPE_DEV_IRAM, 286 dmaengine_dma_dev(pcm, substream), 287 prealloc_buffer_size, 288 max_buffer_size); 289 if (ret) 290 return ret; 291 292 /* 293 * This will only return false if we know for sure that at least 294 * one channel does not support residue reporting. If the DMA 295 * driver does not implement the slave_caps API we rely having 296 * the NO_RESIDUE flag set manually in case residue reporting is 297 * not supported. 298 */ 299 if (!dmaengine_pcm_can_report_residue(pcm->chan[i])) 300 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE; 301 } 302 303 return 0; 304 } 305 306 static snd_pcm_uframes_t dmaengine_pcm_pointer( 307 struct snd_pcm_substream *substream) 308 { 309 struct snd_soc_pcm_runtime *rtd = substream->private_data; 310 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 311 312 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 313 return snd_dmaengine_pcm_pointer_no_residue(substream); 314 else 315 return snd_dmaengine_pcm_pointer(substream); 316 } 317 318 static const struct snd_pcm_ops dmaengine_pcm_ops = { 319 .open = dmaengine_pcm_open, 320 .close = snd_dmaengine_pcm_close, 321 .ioctl = snd_pcm_lib_ioctl, 322 .hw_params = dmaengine_pcm_hw_params, 323 .hw_free = snd_pcm_lib_free_pages, 324 .trigger = snd_dmaengine_pcm_trigger, 325 .pointer = dmaengine_pcm_pointer, 326 }; 327 328 static const struct snd_soc_platform_driver dmaengine_pcm_platform = { 329 .component_driver = { 330 .probe_order = SND_SOC_COMP_ORDER_LATE, 331 }, 332 .ops = &dmaengine_pcm_ops, 333 .pcm_new = dmaengine_pcm_new, 334 }; 335 336 static const char * const dmaengine_pcm_dma_channel_names[] = { 337 [SNDRV_PCM_STREAM_PLAYBACK] = "tx", 338 [SNDRV_PCM_STREAM_CAPTURE] = "rx", 339 }; 340 341 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, 342 struct device *dev, const struct snd_dmaengine_pcm_config *config) 343 { 344 unsigned int i; 345 const char *name; 346 struct dma_chan *chan; 347 348 if ((pcm->flags & (SND_DMAENGINE_PCM_FLAG_NO_DT | 349 SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) || 350 !dev->of_node) 351 return 0; 352 353 if (config && config->dma_dev) { 354 /* 355 * If this warning is seen, it probably means that your Linux 356 * device structure does not match your HW device structure. 357 * It would be best to refactor the Linux device structure to 358 * correctly match the HW structure. 359 */ 360 dev_warn(dev, "DMA channels sourced from device %s", 361 dev_name(config->dma_dev)); 362 dev = config->dma_dev; 363 } 364 365 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 366 i++) { 367 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 368 name = "rx-tx"; 369 else 370 name = dmaengine_pcm_dma_channel_names[i]; 371 if (config && config->chan_names[i]) 372 name = config->chan_names[i]; 373 chan = dma_request_slave_channel_reason(dev, name); 374 if (IS_ERR(chan)) { 375 if (PTR_ERR(chan) == -EPROBE_DEFER) 376 return -EPROBE_DEFER; 377 pcm->chan[i] = NULL; 378 } else { 379 pcm->chan[i] = chan; 380 } 381 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 382 break; 383 } 384 385 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 386 pcm->chan[1] = pcm->chan[0]; 387 388 return 0; 389 } 390 391 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) 392 { 393 unsigned int i; 394 395 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 396 i++) { 397 if (!pcm->chan[i]) 398 continue; 399 dma_release_channel(pcm->chan[i]); 400 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 401 break; 402 } 403 } 404 405 /** 406 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device 407 * @dev: The parent device for the PCM device 408 * @config: Platform specific PCM configuration 409 * @flags: Platform specific quirks 410 */ 411 int snd_dmaengine_pcm_register(struct device *dev, 412 const struct snd_dmaengine_pcm_config *config, unsigned int flags) 413 { 414 struct dmaengine_pcm *pcm; 415 int ret; 416 417 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); 418 if (!pcm) 419 return -ENOMEM; 420 421 pcm->config = config; 422 pcm->flags = flags; 423 424 ret = dmaengine_pcm_request_chan_of(pcm, dev, config); 425 if (ret) 426 goto err_free_dma; 427 428 ret = snd_soc_add_platform(dev, &pcm->platform, 429 &dmaengine_pcm_platform); 430 if (ret) 431 goto err_free_dma; 432 433 return 0; 434 435 err_free_dma: 436 dmaengine_pcm_release_chan(pcm); 437 kfree(pcm); 438 return ret; 439 } 440 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); 441 442 /** 443 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device 444 * @dev: Parent device the PCM was register with 445 * 446 * Removes a dmaengine based PCM device previously registered with 447 * snd_dmaengine_pcm_register. 448 */ 449 void snd_dmaengine_pcm_unregister(struct device *dev) 450 { 451 struct snd_soc_platform *platform; 452 struct dmaengine_pcm *pcm; 453 454 platform = snd_soc_lookup_platform(dev); 455 if (!platform) 456 return; 457 458 pcm = soc_platform_to_pcm(platform); 459 460 snd_soc_remove_platform(platform); 461 dmaengine_pcm_release_chan(pcm); 462 kfree(pcm); 463 } 464 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); 465 466 MODULE_LICENSE("GPL"); 467