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

   1 // SPDX-License-Identifier: GPL-2.0+
   2 //
   3 //  Copyright (C) 2013, Analog Devices Inc.
   4 //      Author: Lars-Peter Clausen <lars@metafoo.de>
   5
   6 #include <linux/module.h>
   7 #include <linux/init.h>
   8 #include <linux/dmaengine.h>
   9 #include <linux/slab.h>
  10 #include <sound/pcm.h>
  11 #include <sound/pcm_params.h>
  12 #include <sound/soc.h>
  13 #include <linux/dma-mapping.h>
  14 #include <linux/of.h>
  15
  16 #include <sound/dmaengine_pcm.h>
  17
  18 /*
  19  * The platforms dmaengine driver does not support reporting the amount of
  20  * bytes that are still left to transfer.
  21  */
  22 #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31)
  23
  24 struct dmaengine_pcm {
  25         struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1];
  26         const struct snd_dmaengine_pcm_config *config;
  27         struct snd_soc_component component;
  28         unsigned int flags;
  29 };
  30
  31 static struct dmaengine_pcm *soc_component_to_pcm(struct snd_soc_component *p)
  32 {
  33         return container_of(p, struct dmaengine_pcm, component);
  34 }
  35
  36 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm,
  37         struct snd_pcm_substream *substream)
  38 {
  39         if (!pcm->chan[substream->stream])
  40                 return NULL;
  41
  42         return pcm->chan[substream->stream]->device->dev;
  43 }
  44
  45 /**
  46  * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback
  47  * @substream: PCM substream
  48  * @params: hw_params
  49  * @slave_config: DMA slave config to prepare
  50  *
  51  * This function can be used as a generic prepare_slave_config callback for
  52  * platforms which make use of the snd_dmaengine_dai_dma_data struct for their
  53  * DAI DMA data. Internally the function will first call
  54  * snd_hwparams_to_dma_slave_config to fill in the slave config based on the
  55  * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the
  56  * remaining fields based on the DAI DMA data.
  57  */
  58 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
  59         struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
  60 {
  61         struct snd_soc_pcm_runtime *rtd = substream->private_data;
  62         struct snd_dmaengine_dai_dma_data *dma_data;
  63         int ret;
  64
  65         dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
  66
  67         ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
  68         if (ret)
  69                 return ret;
  70
  71         snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data,
  72                 slave_config);
  73
  74         return 0;
  75 }
  76 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);
  77
  78 static int dmaengine_pcm_hw_params(struct snd_soc_component *component,
  79                                    struct snd_pcm_substream *substream,
  80                                    struct snd_pcm_hw_params *params)
  81 {
  82         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
  83         struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
  84         int (*prepare_slave_config)(struct snd_pcm_substream *substream,
  85                         struct snd_pcm_hw_params *params,
  86                         struct dma_slave_config *slave_config);
  87         struct dma_slave_config slave_config;
  88         int ret;
  89
  90         memset(&slave_config, 0, sizeof(slave_config));
  91
  92         if (!pcm->config)
  93                 prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config;
  94         else
  95                 prepare_slave_config = pcm->config->prepare_slave_config;
  96
  97         if (prepare_slave_config) {
  98                 ret = prepare_slave_config(substream, params, &slave_config);
  99                 if (ret)
 100                         return ret;
 101
 102                 ret = dmaengine_slave_config(chan, &slave_config);
 103                 if (ret)
 104                         return ret;
 105         }
 106
 107         return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
 108 }
 109
 110 static int
 111 dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component,
 112                                    struct snd_pcm_substream *substream)
 113 {
 114         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 115         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 116         struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
 117         struct dma_chan *chan = pcm->chan[substream->stream];
 118         struct snd_dmaengine_dai_dma_data *dma_data;
 119         struct snd_pcm_hardware hw;
 120
 121         if (pcm->config && pcm->config->pcm_hardware)
 122                 return snd_soc_set_runtime_hwparams(substream,
 123                                 pcm->config->pcm_hardware);
 124
 125         dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 126
 127         memset(&hw, 0, sizeof(hw));
 128         hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
 129                         SNDRV_PCM_INFO_INTERLEAVED;
 130         hw.periods_min = 2;
 131         hw.periods_max = UINT_MAX;
 132         hw.period_bytes_min = 256;
 133         hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
 134         hw.buffer_bytes_max = SIZE_MAX;
 135         hw.fifo_size = dma_data->fifo_size;
 136
 137         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
 138                 hw.info |= SNDRV_PCM_INFO_BATCH;
 139
 140         /**
 141          * FIXME: Remove the return value check to align with the code
 142          * before adding snd_dmaengine_pcm_refine_runtime_hwparams
 143          * function.
 144          */
 145         snd_dmaengine_pcm_refine_runtime_hwparams(substream,
 146                                                   dma_data,
 147                                                   &hw,
 148                                                   chan);
 149
 150         return snd_soc_set_runtime_hwparams(substream, &hw);
 151 }
 152
 153 static int dmaengine_pcm_open(struct snd_soc_component *component,
 154                               struct snd_pcm_substream *substream)
 155 {
 156         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 157         struct dma_chan *chan = pcm->chan[substream->stream];
 158         int ret;
 159
 160         ret = dmaengine_pcm_set_runtime_hwparams(component, substream);
 161         if (ret)
 162                 return ret;
 163
 164         return snd_dmaengine_pcm_open(substream, chan);
 165 }
 166
 167 static int dmaengine_pcm_close(struct snd_soc_component *component,
 168                                struct snd_pcm_substream *substream)
 169 {
 170         return snd_dmaengine_pcm_close(substream);
 171 }
 172
 173 static int dmaengine_pcm_hw_free(struct snd_soc_component *component,
 174                                  struct snd_pcm_substream *substream)
 175 {
 176         return snd_pcm_lib_free_pages(substream);
 177 }
 178
 179 static int dmaengine_pcm_trigger(struct snd_soc_component *component,
 180                                  struct snd_pcm_substream *substream, int cmd)
 181 {
 182         return snd_dmaengine_pcm_trigger(substream, cmd);
 183 }
 184
 185 static struct dma_chan *dmaengine_pcm_compat_request_channel(
 186         struct snd_soc_component *component,
 187         struct snd_soc_pcm_runtime *rtd,
 188         struct snd_pcm_substream *substream)
 189 {
 190         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 191         struct snd_dmaengine_dai_dma_data *dma_data;
 192         dma_filter_fn fn = NULL;
 193
 194         dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 195
 196         if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
 197                 return pcm->chan[0];
 198
 199         if (pcm->config && pcm->config->compat_request_channel)
 200                 return pcm->config->compat_request_channel(rtd, substream);
 201
 202         if (pcm->config)
 203                 fn = pcm->config->compat_filter_fn;
 204
 205         return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data);
 206 }
 207
 208 static bool dmaengine_pcm_can_report_residue(struct device *dev,
 209         struct dma_chan *chan)
 210 {
 211         struct dma_slave_caps dma_caps;
 212         int ret;
 213
 214         ret = dma_get_slave_caps(chan, &dma_caps);
 215         if (ret != 0) {
 216                 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n",
 217                          ret);
 218                 return false;
 219         }
 220
 221         if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR)
 222                 return false;
 223
 224         return true;
 225 }
 226
 227 static int dmaengine_pcm_new(struct snd_soc_component *component,
 228                              struct snd_soc_pcm_runtime *rtd)
 229 {
 230         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 231         const struct snd_dmaengine_pcm_config *config = pcm->config;
 232         struct device *dev = component->dev;
 233         struct snd_pcm_substream *substream;
 234         size_t prealloc_buffer_size;
 235         size_t max_buffer_size;
 236         unsigned int i;
 237
 238         if (config && config->prealloc_buffer_size) {
 239                 prealloc_buffer_size = config->prealloc_buffer_size;
 240                 max_buffer_size = config->pcm_hardware->buffer_bytes_max;
 241         } else {
 242                 prealloc_buffer_size = 512 * 1024;
 243                 max_buffer_size = SIZE_MAX;
 244         }
 245
 246         for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
 247                 substream = rtd->pcm->streams[i].substream;
 248                 if (!substream)
 249                         continue;
 250
 251                 if (!pcm->chan[i] && config && config->chan_names[i])
 252                         pcm->chan[i] = dma_request_slave_channel(dev,
 253                                 config->chan_names[i]);
 254
 255                 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
 256                         pcm->chan[i] = dmaengine_pcm_compat_request_channel(
 257                                 component, rtd, substream);
 258                 }
 259
 260                 if (!pcm->chan[i]) {
 261                         dev_err(component->dev,
 262                                 "Missing dma channel for stream: %d\n", i);
 263                         return -EINVAL;
 264                 }
 265
 266                 snd_pcm_lib_preallocate_pages(substream,
 267                                 SNDRV_DMA_TYPE_DEV_IRAM,
 268                                 dmaengine_dma_dev(pcm, substream),
 269                                 prealloc_buffer_size,
 270                                 max_buffer_size);
 271
 272                 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
 273                         pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
 274
 275                 if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
 276                         strscpy_pad(rtd->pcm->streams[i].pcm->name,
 277                                     rtd->pcm->streams[i].pcm->id,
 278                                     sizeof(rtd->pcm->streams[i].pcm->name));
 279                 }
 280         }
 281
 282         return 0;
 283 }
 284
 285 static snd_pcm_uframes_t dmaengine_pcm_pointer(
 286         struct snd_soc_component *component,
 287         struct snd_pcm_substream *substream)
 288 {
 289         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 290
 291         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
 292                 return snd_dmaengine_pcm_pointer_no_residue(substream);
 293         else
 294                 return snd_dmaengine_pcm_pointer(substream);
 295 }
 296
 297 static int dmaengine_copy_user(struct snd_soc_component *component,
 298                                struct snd_pcm_substream *substream,
 299                                int channel, unsigned long hwoff,
 300                                void __user *buf, unsigned long bytes)
 301 {
 302         struct snd_pcm_runtime *runtime = substream->runtime;
 303         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 304         int (*process)(struct snd_pcm_substream *substream,
 305                        int channel, unsigned long hwoff,
 306                        void *buf, unsigned long bytes) = pcm->config->process;
 307         bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 308         void *dma_ptr = runtime->dma_area + hwoff +
 309                         channel * (runtime->dma_bytes / runtime->channels);
 310         int ret;
 311
 312         if (is_playback)
 313                 if (copy_from_user(dma_ptr, buf, bytes))
 314                         return -EFAULT;
 315
 316         if (process) {
 317                 ret = process(substream, channel, hwoff, (__force void *)buf, bytes);
 318                 if (ret < 0)
 319                         return ret;
 320         }
 321
 322         if (!is_playback)
 323                 if (copy_to_user(buf, dma_ptr, bytes))
 324                         return -EFAULT;
 325
 326         return 0;
 327 }
 328
 329 static const struct snd_soc_component_driver dmaengine_pcm_component = {
 330         .name           = SND_DMAENGINE_PCM_DRV_NAME,
 331         .probe_order    = SND_SOC_COMP_ORDER_LATE,
 332         .open           = dmaengine_pcm_open,
 333         .close          = dmaengine_pcm_close,
 334         .ioctl          = snd_soc_pcm_lib_ioctl,
 335         .hw_params      = dmaengine_pcm_hw_params,
 336         .hw_free        = dmaengine_pcm_hw_free,
 337         .trigger        = dmaengine_pcm_trigger,
 338         .pointer        = dmaengine_pcm_pointer,
 339         .pcm_construct  = dmaengine_pcm_new,
 340 };
 341
 342 static const struct snd_soc_component_driver dmaengine_pcm_component_process = {
 343         .name           = SND_DMAENGINE_PCM_DRV_NAME,
 344         .probe_order    = SND_SOC_COMP_ORDER_LATE,
 345         .open           = dmaengine_pcm_open,
 346         .close          = dmaengine_pcm_close,
 347         .ioctl          = snd_soc_pcm_lib_ioctl,
 348         .hw_params      = dmaengine_pcm_hw_params,
 349         .hw_free        = dmaengine_pcm_hw_free,
 350         .trigger        = dmaengine_pcm_trigger,
 351         .pointer        = dmaengine_pcm_pointer,
 352         .copy_user      = dmaengine_copy_user,
 353         .pcm_construct  = dmaengine_pcm_new,
 354 };
 355
 356 static const char * const dmaengine_pcm_dma_channel_names[] = {
 357         [SNDRV_PCM_STREAM_PLAYBACK] = "tx",
 358         [SNDRV_PCM_STREAM_CAPTURE] = "rx",
 359 };
 360
 361 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
 362         struct device *dev, const struct snd_dmaengine_pcm_config *config)
 363 {
 364         unsigned int i;
 365         const char *name;
 366         struct dma_chan *chan;
 367
 368         if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node &&
 369             !(config && config->dma_dev && config->dma_dev->of_node)))
 370                 return 0;
 371
 372         if (config && config->dma_dev) {
 373                 /*
 374                  * If this warning is seen, it probably means that your Linux
 375                  * device structure does not match your HW device structure.
 376                  * It would be best to refactor the Linux device structure to
 377                  * correctly match the HW structure.
 378                  */
 379                 dev_warn(dev, "DMA channels sourced from device %s",
 380                          dev_name(config->dma_dev));
 381                 dev = config->dma_dev;
 382         }
 383
 384         for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
 385              i++) {
 386                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 387                         name = "rx-tx";
 388                 else
 389                         name = dmaengine_pcm_dma_channel_names[i];
 390                 if (config && config->chan_names[i])
 391                         name = config->chan_names[i];
 392                 chan = dma_request_chan(dev, name);
 393                 if (IS_ERR(chan)) {
 394                         if (PTR_ERR(chan) == -EPROBE_DEFER)
 395                                 return -EPROBE_DEFER;
 396                         pcm->chan[i] = NULL;
 397                 } else {
 398                         pcm->chan[i] = chan;
 399                 }
 400                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 401                         break;
 402         }
 403
 404         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 405                 pcm->chan[1] = pcm->chan[0];
 406
 407         return 0;
 408 }
 409
 410 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm)
 411 {
 412         unsigned int i;
 413
 414         for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
 415              i++) {
 416                 if (!pcm->chan[i])
 417                         continue;
 418                 dma_release_channel(pcm->chan[i]);
 419                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 420                         break;
 421         }
 422 }
 423
 424 /**
 425  * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
 426  * @dev: The parent device for the PCM device
 427  * @config: Platform specific PCM configuration
 428  * @flags: Platform specific quirks
 429  */
 430 int snd_dmaengine_pcm_register(struct device *dev,
 431         const struct snd_dmaengine_pcm_config *config, unsigned int flags)
 432 {
 433         struct dmaengine_pcm *pcm;
 434         int ret;
 435
 436         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 437         if (!pcm)
 438                 return -ENOMEM;
 439
 440 #ifdef CONFIG_DEBUG_FS
 441         pcm->component.debugfs_prefix = "dma";
 442 #endif
 443         pcm->config = config;
 444         pcm->flags = flags;
 445
 446         ret = dmaengine_pcm_request_chan_of(pcm, dev, config);
 447         if (ret)
 448                 goto err_free_dma;
 449
 450         if (config && config->process)
 451                 ret = snd_soc_add_component(dev, &pcm->component,
 452                                             &dmaengine_pcm_component_process,
 453                                             NULL, 0);
 454         else
 455                 ret = snd_soc_add_component(dev, &pcm->component,
 456                                             &dmaengine_pcm_component, NULL, 0);
 457         if (ret)
 458                 goto err_free_dma;
 459
 460         return 0;
 461
 462 err_free_dma:
 463         dmaengine_pcm_release_chan(pcm);
 464         kfree(pcm);
 465         return ret;
 466 }
 467 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
 468
 469 /**
 470  * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
 471  * @dev: Parent device the PCM was register with
 472  *
 473  * Removes a dmaengine based PCM device previously registered with
 474  * snd_dmaengine_pcm_register.
 475  */
 476 void snd_dmaengine_pcm_unregister(struct device *dev)
 477 {
 478         struct snd_soc_component *component;
 479         struct dmaengine_pcm *pcm;
 480
 481         component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME);
 482         if (!component)
 483                 return;
 484
 485         pcm = soc_component_to_pcm(component);
 486
 487         snd_soc_unregister_component(dev);
 488         dmaengine_pcm_release_chan(pcm);
 489         kfree(pcm);
 490 }
 491 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
 492
 493 MODULE_LICENSE("GPL");