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 int ret; 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(rtd->cpu_dai, 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 ret = dma_get_slave_caps(chan, &dma_caps); 144 if (ret == 0) { 145 if (dma_caps.cmd_pause) 146 hw.info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME; 147 if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT) 148 hw.info |= SNDRV_PCM_INFO_BATCH; 149 } 150 151 return snd_soc_set_runtime_hwparams(substream, &hw); 152 } 153 154 static int dmaengine_pcm_open(struct snd_pcm_substream *substream) 155 { 156 struct snd_soc_pcm_runtime *rtd = substream->private_data; 157 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 158 struct dma_chan *chan = pcm->chan[substream->stream]; 159 int ret; 160 161 ret = dmaengine_pcm_set_runtime_hwparams(substream); 162 if (ret) 163 return ret; 164 165 return snd_dmaengine_pcm_open(substream, chan); 166 } 167 168 static void dmaengine_pcm_free(struct snd_pcm *pcm) 169 { 170 snd_pcm_lib_preallocate_free_for_all(pcm); 171 } 172 173 static struct dma_chan *dmaengine_pcm_compat_request_channel( 174 struct snd_soc_pcm_runtime *rtd, 175 struct snd_pcm_substream *substream) 176 { 177 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 178 struct snd_dmaengine_dai_dma_data *dma_data; 179 dma_filter_fn fn = NULL; 180 181 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 182 183 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0]) 184 return pcm->chan[0]; 185 186 if (pcm->config && pcm->config->compat_request_channel) 187 return pcm->config->compat_request_channel(rtd, substream); 188 189 if (pcm->config) 190 fn = pcm->config->compat_filter_fn; 191 192 return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data); 193 } 194 195 static bool dmaengine_pcm_can_report_residue(struct dma_chan *chan) 196 { 197 struct dma_slave_caps dma_caps; 198 int ret; 199 200 ret = dma_get_slave_caps(chan, &dma_caps); 201 if (ret != 0) 202 return true; 203 204 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) 205 return false; 206 207 return true; 208 } 209 210 static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd) 211 { 212 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 213 const struct snd_dmaengine_pcm_config *config = pcm->config; 214 struct device *dev = rtd->platform->dev; 215 struct snd_dmaengine_dai_dma_data *dma_data; 216 struct snd_pcm_substream *substream; 217 size_t prealloc_buffer_size; 218 size_t max_buffer_size; 219 unsigned int i; 220 int ret; 221 222 if (config && config->prealloc_buffer_size) { 223 prealloc_buffer_size = config->prealloc_buffer_size; 224 max_buffer_size = config->pcm_hardware->buffer_bytes_max; 225 } else { 226 prealloc_buffer_size = 512 * 1024; 227 max_buffer_size = SIZE_MAX; 228 } 229 230 231 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { 232 substream = rtd->pcm->streams[i].substream; 233 if (!substream) 234 continue; 235 236 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 237 238 if (!pcm->chan[i] && 239 (pcm->flags & SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) 240 pcm->chan[i] = dma_request_slave_channel(dev, 241 dma_data->chan_name); 242 243 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) { 244 pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd, 245 substream); 246 } 247 248 if (!pcm->chan[i]) { 249 dev_err(rtd->platform->dev, 250 "Missing dma channel for stream: %d\n", i); 251 ret = -EINVAL; 252 goto err_free; 253 } 254 255 ret = snd_pcm_lib_preallocate_pages(substream, 256 SNDRV_DMA_TYPE_DEV_IRAM, 257 dmaengine_dma_dev(pcm, substream), 258 prealloc_buffer_size, 259 max_buffer_size); 260 if (ret) 261 goto err_free; 262 263 /* 264 * This will only return false if we know for sure that at least 265 * one channel does not support residue reporting. If the DMA 266 * driver does not implement the slave_caps API we rely having 267 * the NO_RESIDUE flag set manually in case residue reporting is 268 * not supported. 269 */ 270 if (!dmaengine_pcm_can_report_residue(pcm->chan[i])) 271 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE; 272 } 273 274 return 0; 275 276 err_free: 277 dmaengine_pcm_free(rtd->pcm); 278 return ret; 279 } 280 281 static snd_pcm_uframes_t dmaengine_pcm_pointer( 282 struct snd_pcm_substream *substream) 283 { 284 struct snd_soc_pcm_runtime *rtd = substream->private_data; 285 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 286 287 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 288 return snd_dmaengine_pcm_pointer_no_residue(substream); 289 else 290 return snd_dmaengine_pcm_pointer(substream); 291 } 292 293 static const struct snd_pcm_ops dmaengine_pcm_ops = { 294 .open = dmaengine_pcm_open, 295 .close = snd_dmaengine_pcm_close, 296 .ioctl = snd_pcm_lib_ioctl, 297 .hw_params = dmaengine_pcm_hw_params, 298 .hw_free = snd_pcm_lib_free_pages, 299 .trigger = snd_dmaengine_pcm_trigger, 300 .pointer = dmaengine_pcm_pointer, 301 }; 302 303 static const struct snd_soc_platform_driver dmaengine_pcm_platform = { 304 .ops = &dmaengine_pcm_ops, 305 .pcm_new = dmaengine_pcm_new, 306 .pcm_free = dmaengine_pcm_free, 307 .probe_order = SND_SOC_COMP_ORDER_LATE, 308 }; 309 310 static const char * const dmaengine_pcm_dma_channel_names[] = { 311 [SNDRV_PCM_STREAM_PLAYBACK] = "tx", 312 [SNDRV_PCM_STREAM_CAPTURE] = "rx", 313 }; 314 315 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, 316 struct device *dev, const struct snd_dmaengine_pcm_config *config) 317 { 318 unsigned int i; 319 const char *name; 320 struct dma_chan *chan; 321 322 if ((pcm->flags & (SND_DMAENGINE_PCM_FLAG_NO_DT | 323 SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) || 324 !dev->of_node) 325 return 0; 326 327 if (config && config->dma_dev) { 328 /* 329 * If this warning is seen, it probably means that your Linux 330 * device structure does not match your HW device structure. 331 * It would be best to refactor the Linux device structure to 332 * correctly match the HW structure. 333 */ 334 dev_warn(dev, "DMA channels sourced from device %s", 335 dev_name(config->dma_dev)); 336 dev = config->dma_dev; 337 } 338 339 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 340 i++) { 341 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 342 name = "rx-tx"; 343 else 344 name = dmaengine_pcm_dma_channel_names[i]; 345 if (config && config->chan_names[i]) 346 name = config->chan_names[i]; 347 chan = dma_request_slave_channel_reason(dev, name); 348 if (IS_ERR(chan)) { 349 if (PTR_ERR(chan) == -EPROBE_DEFER) 350 return -EPROBE_DEFER; 351 pcm->chan[i] = NULL; 352 } else { 353 pcm->chan[i] = chan; 354 } 355 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 356 break; 357 } 358 359 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 360 pcm->chan[1] = pcm->chan[0]; 361 362 return 0; 363 } 364 365 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) 366 { 367 unsigned int i; 368 369 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; 370 i++) { 371 if (!pcm->chan[i]) 372 continue; 373 dma_release_channel(pcm->chan[i]); 374 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 375 break; 376 } 377 } 378 379 /** 380 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device 381 * @dev: The parent device for the PCM device 382 * @config: Platform specific PCM configuration 383 * @flags: Platform specific quirks 384 */ 385 int snd_dmaengine_pcm_register(struct device *dev, 386 const struct snd_dmaengine_pcm_config *config, unsigned int flags) 387 { 388 struct dmaengine_pcm *pcm; 389 int ret; 390 391 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); 392 if (!pcm) 393 return -ENOMEM; 394 395 pcm->config = config; 396 pcm->flags = flags; 397 398 ret = dmaengine_pcm_request_chan_of(pcm, dev, config); 399 if (ret) 400 goto err_free_dma; 401 402 ret = snd_soc_add_platform(dev, &pcm->platform, 403 &dmaengine_pcm_platform); 404 if (ret) 405 goto err_free_dma; 406 407 return 0; 408 409 err_free_dma: 410 dmaengine_pcm_release_chan(pcm); 411 kfree(pcm); 412 return ret; 413 } 414 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); 415 416 /** 417 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device 418 * @dev: Parent device the PCM was register with 419 * 420 * Removes a dmaengine based PCM device previously registered with 421 * snd_dmaengine_pcm_register. 422 */ 423 void snd_dmaengine_pcm_unregister(struct device *dev) 424 { 425 struct snd_soc_platform *platform; 426 struct dmaengine_pcm *pcm; 427 428 platform = snd_soc_lookup_platform(dev); 429 if (!platform) 430 return; 431 432 pcm = soc_platform_to_pcm(platform); 433 434 snd_soc_remove_platform(platform); 435 dmaengine_pcm_release_chan(pcm); 436 kfree(pcm); 437 } 438 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); 439 440 MODULE_LICENSE("GPL"); 441