sound/soc/soc-generic-dmaengine-pcm.c

   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");