kernel/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         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");