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 /*
  28  * The platforms dmaengine driver does not support reporting the amount of
  29  * bytes that are still left to transfer.
  30  */
  31 #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31)
  32
  33 struct dmaengine_pcm {
  34         struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1];
  35         const struct snd_dmaengine_pcm_config *config;
  36         struct snd_soc_component component;
  37         unsigned int flags;
  38 };
  39
  40 static struct dmaengine_pcm *soc_component_to_pcm(struct snd_soc_component *p)
  41 {
  42         return container_of(p, struct dmaengine_pcm, component);
  43 }
  44
  45 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm,
  46         struct snd_pcm_substream *substream)
  47 {
  48         if (!pcm->chan[substream->stream])
  49                 return NULL;
  50
  51         return pcm->chan[substream->stream]->device->dev;
  52 }
  53
  54 /**
  55  * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback
  56  * @substream: PCM substream
  57  * @params: hw_params
  58  * @slave_config: DMA slave config to prepare
  59  *
  60  * This function can be used as a generic prepare_slave_config callback for
  61  * platforms which make use of the snd_dmaengine_dai_dma_data struct for their
  62  * DAI DMA data. Internally the function will first call
  63  * snd_hwparams_to_dma_slave_config to fill in the slave config based on the
  64  * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the
  65  * remaining fields based on the DAI DMA data.
  66  */
  67 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
  68         struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
  69 {
  70         struct snd_soc_pcm_runtime *rtd = substream->private_data;
  71         struct snd_dmaengine_dai_dma_data *dma_data;
  72         int ret;
  73
  74         dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
  75
  76         ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
  77         if (ret)
  78                 return ret;
  79
  80         snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data,
  81                 slave_config);
  82
  83         return 0;
  84 }
  85 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);
  86
  87 static int dmaengine_pcm_hw_params(struct snd_pcm_substream *substream,
  88         struct snd_pcm_hw_params *params)
  89 {
  90         struct snd_soc_pcm_runtime *rtd = substream->private_data;
  91         struct snd_soc_component *component =
  92                 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME);
  93         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
  94         struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
  95         int (*prepare_slave_config)(struct snd_pcm_substream *substream,
  96                         struct snd_pcm_hw_params *params,
  97                         struct dma_slave_config *slave_config);
  98         struct dma_slave_config slave_config;
  99         int ret;
 100
 101         memset(&slave_config, 0, sizeof(slave_config));
 102
 103         if (!pcm->config)
 104                 prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config;
 105         else
 106                 prepare_slave_config = pcm->config->prepare_slave_config;
 107
 108         if (prepare_slave_config) {
 109                 ret = prepare_slave_config(substream, params, &slave_config);
 110                 if (ret)
 111                         return ret;
 112
 113                 ret = dmaengine_slave_config(chan, &slave_config);
 114                 if (ret)
 115                         return ret;
 116         }
 117
 118         return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
 119 }
 120
 121 static int dmaengine_pcm_set_runtime_hwparams(struct snd_pcm_substream *substream)
 122 {
 123         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 124         struct snd_soc_component *component =
 125                 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME);
 126         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 127         struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
 128         struct dma_chan *chan = pcm->chan[substream->stream];
 129         struct snd_dmaengine_dai_dma_data *dma_data;
 130         struct dma_slave_caps dma_caps;
 131         struct snd_pcm_hardware hw;
 132         u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
 133                           BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
 134                           BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
 135         snd_pcm_format_t i;
 136         int ret;
 137
 138         if (pcm->config && pcm->config->pcm_hardware)
 139                 return snd_soc_set_runtime_hwparams(substream,
 140                                 pcm->config->pcm_hardware);
 141
 142         dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 143
 144         memset(&hw, 0, sizeof(hw));
 145         hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
 146                         SNDRV_PCM_INFO_INTERLEAVED;
 147         hw.periods_min = 2;
 148         hw.periods_max = UINT_MAX;
 149         hw.period_bytes_min = 256;
 150         hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
 151         hw.buffer_bytes_max = SIZE_MAX;
 152         hw.fifo_size = dma_data->fifo_size;
 153
 154         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
 155                 hw.info |= SNDRV_PCM_INFO_BATCH;
 156
 157         ret = dma_get_slave_caps(chan, &dma_caps);
 158         if (ret == 0) {
 159                 if (dma_caps.cmd_pause)
 160                         hw.info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME;
 161                 if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT)
 162                         hw.info |= SNDRV_PCM_INFO_BATCH;
 163
 164                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 165                         addr_widths = dma_caps.dst_addr_widths;
 166                 else
 167                         addr_widths = dma_caps.src_addr_widths;
 168         }
 169
 170         /*
 171          * If SND_DMAENGINE_PCM_DAI_FLAG_PACK is set keep
 172          * hw.formats set to 0, meaning no restrictions are in place.
 173          * In this case it's the responsibility of the DAI driver to
 174          * provide the supported format information.
 175          */
 176         if (!(dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK))
 177                 /*
 178                  * Prepare formats mask for valid/allowed sample types. If the
 179                  * dma does not have support for the given physical word size,
 180                  * it needs to be masked out so user space can not use the
 181                  * format which produces corrupted audio.
 182                  * In case the dma driver does not implement the slave_caps the
 183                  * default assumption is that it supports 1, 2 and 4 bytes
 184                  * widths.
 185                  */
 186                 for (i = SNDRV_PCM_FORMAT_FIRST; i <= SNDRV_PCM_FORMAT_LAST; i++) {
 187                         int bits = snd_pcm_format_physical_width(i);
 188
 189                         /*
 190                          * Enable only samples with DMA supported physical
 191                          * widths
 192                          */
 193                         switch (bits) {
 194                         case 8:
 195                         case 16:
 196                         case 24:
 197                         case 32:
 198                         case 64:
 199                                 if (addr_widths & (1 << (bits / 8)))
 200                                         hw.formats |= (1LL << i);
 201                                 break;
 202                         default:
 203                                 /* Unsupported types */
 204                                 break;
 205                         }
 206                 }
 207
 208         return snd_soc_set_runtime_hwparams(substream, &hw);
 209 }
 210
 211 static int dmaengine_pcm_open(struct snd_pcm_substream *substream)
 212 {
 213         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 214         struct snd_soc_component *component =
 215                 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME);
 216         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 217         struct dma_chan *chan = pcm->chan[substream->stream];
 218         int ret;
 219
 220         ret = dmaengine_pcm_set_runtime_hwparams(substream);
 221         if (ret)
 222                 return ret;
 223
 224         return snd_dmaengine_pcm_open(substream, chan);
 225 }
 226
 227 static struct dma_chan *dmaengine_pcm_compat_request_channel(
 228         struct snd_soc_pcm_runtime *rtd,
 229         struct snd_pcm_substream *substream)
 230 {
 231         struct snd_soc_component *component =
 232                 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME);
 233         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 234         struct snd_dmaengine_dai_dma_data *dma_data;
 235         dma_filter_fn fn = NULL;
 236
 237         dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 238
 239         if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
 240                 return pcm->chan[0];
 241
 242         if (pcm->config && pcm->config->compat_request_channel)
 243                 return pcm->config->compat_request_channel(rtd, substream);
 244
 245         if (pcm->config)
 246                 fn = pcm->config->compat_filter_fn;
 247
 248         return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data);
 249 }
 250
 251 static bool dmaengine_pcm_can_report_residue(struct device *dev,
 252         struct dma_chan *chan)
 253 {
 254         struct dma_slave_caps dma_caps;
 255         int ret;
 256
 257         ret = dma_get_slave_caps(chan, &dma_caps);
 258         if (ret != 0) {
 259                 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n",
 260                          ret);
 261                 return false;
 262         }
 263
 264         if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR)
 265                 return false;
 266
 267         return true;
 268 }
 269
 270 static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
 271 {
 272         struct snd_soc_component *component =
 273                 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME);
 274         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 275         const struct snd_dmaengine_pcm_config *config = pcm->config;
 276         struct device *dev = component->dev;
 277         struct snd_dmaengine_dai_dma_data *dma_data;
 278         struct snd_pcm_substream *substream;
 279         size_t prealloc_buffer_size;
 280         size_t max_buffer_size;
 281         unsigned int i;
 282         int ret;
 283
 284         if (config && config->prealloc_buffer_size) {
 285                 prealloc_buffer_size = config->prealloc_buffer_size;
 286                 max_buffer_size = config->pcm_hardware->buffer_bytes_max;
 287         } else {
 288                 prealloc_buffer_size = 512 * 1024;
 289                 max_buffer_size = SIZE_MAX;
 290         }
 291
 292         for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
 293                 substream = rtd->pcm->streams[i].substream;
 294                 if (!substream)
 295                         continue;
 296
 297                 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 298
 299                 if (!pcm->chan[i] &&
 300                     (pcm->flags & SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME))
 301                         pcm->chan[i] = dma_request_slave_channel(dev,
 302                                 dma_data->chan_name);
 303
 304                 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
 305                         pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd,
 306                                 substream);
 307                 }
 308
 309                 if (!pcm->chan[i]) {
 310                         dev_err(component->dev,
 311                                 "Missing dma channel for stream: %d\n", i);
 312                         return -EINVAL;
 313                 }
 314
 315                 ret = snd_pcm_lib_preallocate_pages(substream,
 316                                 SNDRV_DMA_TYPE_DEV_IRAM,
 317                                 dmaengine_dma_dev(pcm, substream),
 318                                 prealloc_buffer_size,
 319                                 max_buffer_size);
 320                 if (ret)
 321                         return ret;
 322
 323                 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
 324                         pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
 325         }
 326
 327         return 0;
 328 }
 329
 330 static snd_pcm_uframes_t dmaengine_pcm_pointer(
 331         struct snd_pcm_substream *substream)
 332 {
 333         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 334         struct snd_soc_component *component =
 335                 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME);
 336         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 337
 338         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
 339                 return snd_dmaengine_pcm_pointer_no_residue(substream);
 340         else
 341                 return snd_dmaengine_pcm_pointer(substream);
 342 }
 343
 344 static int dmaengine_copy_user(struct snd_pcm_substream *substream,
 345                                int channel, unsigned long hwoff,
 346                                void *buf, unsigned long bytes)
 347 {
 348         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 349         struct snd_soc_component *component =
 350                 snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME);
 351         struct snd_pcm_runtime *runtime = substream->runtime;
 352         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 353         int (*process)(struct snd_pcm_substream *substream,
 354                        int channel, unsigned long hwoff,
 355                        void *buf, unsigned long bytes) = pcm->config->process;
 356         bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 357         void *dma_ptr = runtime->dma_area + hwoff +
 358                         channel * (runtime->dma_bytes / runtime->channels);
 359         int ret;
 360
 361         if (is_playback)
 362                 if (copy_from_user(dma_ptr, (void __user *)buf, bytes))
 363                         return -EFAULT;
 364
 365         if (process) {
 366                 ret = process(substream, channel, hwoff,
 367                               (void __user *)buf, bytes);
 368                 if (ret < 0)
 369                         return ret;
 370         }
 371
 372         if (!is_playback)
 373                 if (copy_to_user((void __user *)buf, dma_ptr, bytes))
 374                         return -EFAULT;
 375
 376         return 0;
 377 }
 378
 379 static const struct snd_pcm_ops dmaengine_pcm_ops = {
 380         .open           = dmaengine_pcm_open,
 381         .close          = snd_dmaengine_pcm_close,
 382         .ioctl          = snd_pcm_lib_ioctl,
 383         .hw_params      = dmaengine_pcm_hw_params,
 384         .hw_free        = snd_pcm_lib_free_pages,
 385         .trigger        = snd_dmaengine_pcm_trigger,
 386         .pointer        = dmaengine_pcm_pointer,
 387 };
 388
 389 static const struct snd_pcm_ops dmaengine_pcm_process_ops = {
 390         .open           = dmaengine_pcm_open,
 391         .close          = snd_dmaengine_pcm_close,
 392         .ioctl          = snd_pcm_lib_ioctl,
 393         .hw_params      = dmaengine_pcm_hw_params,
 394         .hw_free        = snd_pcm_lib_free_pages,
 395         .trigger        = snd_dmaengine_pcm_trigger,
 396         .pointer        = dmaengine_pcm_pointer,
 397         .copy_user      = dmaengine_copy_user,
 398 };
 399
 400 static const struct snd_soc_component_driver dmaengine_pcm_component = {
 401         .name           = SND_DMAENGINE_PCM_DRV_NAME,
 402         .probe_order    = SND_SOC_COMP_ORDER_LATE,
 403         .ops            = &dmaengine_pcm_ops,
 404         .pcm_new        = dmaengine_pcm_new,
 405 };
 406
 407 static const struct snd_soc_component_driver dmaengine_pcm_component_process = {
 408         .name           = SND_DMAENGINE_PCM_DRV_NAME,
 409         .probe_order    = SND_SOC_COMP_ORDER_LATE,
 410         .ops            = &dmaengine_pcm_process_ops,
 411         .pcm_new        = dmaengine_pcm_new,
 412 };
 413
 414 static const char * const dmaengine_pcm_dma_channel_names[] = {
 415         [SNDRV_PCM_STREAM_PLAYBACK] = "tx",
 416         [SNDRV_PCM_STREAM_CAPTURE] = "rx",
 417 };
 418
 419 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
 420         struct device *dev, const struct snd_dmaengine_pcm_config *config)
 421 {
 422         unsigned int i;
 423         const char *name;
 424         struct dma_chan *chan;
 425
 426         if ((pcm->flags & (SND_DMAENGINE_PCM_FLAG_NO_DT |
 427                            SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) ||
 428             !dev->of_node)
 429                 return 0;
 430
 431         if (config && config->dma_dev) {
 432                 /*
 433                  * If this warning is seen, it probably means that your Linux
 434                  * device structure does not match your HW device structure.
 435                  * It would be best to refactor the Linux device structure to
 436                  * correctly match the HW structure.
 437                  */
 438                 dev_warn(dev, "DMA channels sourced from device %s",
 439                          dev_name(config->dma_dev));
 440                 dev = config->dma_dev;
 441         }
 442
 443         for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
 444              i++) {
 445                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 446                         name = "rx-tx";
 447                 else
 448                         name = dmaengine_pcm_dma_channel_names[i];
 449                 if (config && config->chan_names[i])
 450                         name = config->chan_names[i];
 451                 chan = dma_request_slave_channel_reason(dev, name);
 452                 if (IS_ERR(chan)) {
 453                         if (PTR_ERR(chan) == -EPROBE_DEFER)
 454                                 return -EPROBE_DEFER;
 455                         pcm->chan[i] = NULL;
 456                 } else {
 457                         pcm->chan[i] = chan;
 458                 }
 459                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 460                         break;
 461         }
 462
 463         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 464                 pcm->chan[1] = pcm->chan[0];
 465
 466         return 0;
 467 }
 468
 469 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm)
 470 {
 471         unsigned int i;
 472
 473         for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
 474              i++) {
 475                 if (!pcm->chan[i])
 476                         continue;
 477                 dma_release_channel(pcm->chan[i]);
 478                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 479                         break;
 480         }
 481 }
 482
 483 /**
 484  * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
 485  * @dev: The parent device for the PCM device
 486  * @config: Platform specific PCM configuration
 487  * @flags: Platform specific quirks
 488  */
 489 int snd_dmaengine_pcm_register(struct device *dev,
 490         const struct snd_dmaengine_pcm_config *config, unsigned int flags)
 491 {
 492         struct dmaengine_pcm *pcm;
 493         int ret;
 494
 495         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 496         if (!pcm)
 497                 return -ENOMEM;
 498
 499 #ifdef CONFIG_DEBUG_FS
 500         pcm->component.debugfs_prefix = "dma";
 501 #endif
 502         pcm->config = config;
 503         pcm->flags = flags;
 504
 505         ret = dmaengine_pcm_request_chan_of(pcm, dev, config);
 506         if (ret)
 507                 goto err_free_dma;
 508
 509         if (config && config->process)
 510                 ret = snd_soc_add_component(dev, &pcm->component,
 511                                             &dmaengine_pcm_component_process,
 512                                             NULL, 0);
 513         else
 514                 ret = snd_soc_add_component(dev, &pcm->component,
 515                                             &dmaengine_pcm_component, NULL, 0);
 516         if (ret)
 517                 goto err_free_dma;
 518
 519         return 0;
 520
 521 err_free_dma:
 522         dmaengine_pcm_release_chan(pcm);
 523         kfree(pcm);
 524         return ret;
 525 }
 526 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
 527
 528 /**
 529  * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
 530  * @dev: Parent device the PCM was register with
 531  *
 532  * Removes a dmaengine based PCM device previously registered with
 533  * snd_dmaengine_pcm_register.
 534  */
 535 void snd_dmaengine_pcm_unregister(struct device *dev)
 536 {
 537         struct snd_soc_component *component;
 538         struct dmaengine_pcm *pcm;
 539
 540         component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME);
 541         if (!component)
 542                 return;
 543
 544         pcm = soc_component_to_pcm(component);
 545
 546         snd_soc_unregister_component(dev);
 547         dmaengine_pcm_release_chan(pcm);
 548         kfree(pcm);
 549 }
 550 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
 551
 552 MODULE_LICENSE("GPL");