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         int ret;
 121
 122         if (pcm->config && pcm->config->pcm_hardware)
 123                 return snd_soc_set_runtime_hwparams(substream,
 124                                 pcm->config->pcm_hardware);
 125
 126         dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 127
 128         memset(&hw, 0, sizeof(hw));
 129         hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
 130                         SNDRV_PCM_INFO_INTERLEAVED;
 131         hw.periods_min = 2;
 132         hw.periods_max = UINT_MAX;
 133         hw.period_bytes_min = 256;
 134         hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
 135         hw.buffer_bytes_max = SIZE_MAX;
 136         hw.fifo_size = dma_data->fifo_size;
 137
 138         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
 139                 hw.info |= SNDRV_PCM_INFO_BATCH;
 140
 141         ret = snd_dmaengine_pcm_refine_runtime_hwparams(substream,
 142                                                         dma_data,
 143                                                         &hw,
 144                                                         chan);
 145         if (ret)
 146                 return ret;
 147
 148         return snd_soc_set_runtime_hwparams(substream, &hw);
 149 }
 150
 151 static int dmaengine_pcm_open(struct snd_soc_component *component,
 152                               struct snd_pcm_substream *substream)
 153 {
 154         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 155         struct dma_chan *chan = pcm->chan[substream->stream];
 156         int ret;
 157
 158         ret = dmaengine_pcm_set_runtime_hwparams(component, substream);
 159         if (ret)
 160                 return ret;
 161
 162         return snd_dmaengine_pcm_open(substream, chan);
 163 }
 164
 165 static int dmaengine_pcm_close(struct snd_soc_component *component,
 166                                struct snd_pcm_substream *substream)
 167 {
 168         return snd_dmaengine_pcm_close(substream);
 169 }
 170
 171 static int dmaengine_pcm_hw_free(struct snd_soc_component *component,
 172                                  struct snd_pcm_substream *substream)
 173 {
 174         return snd_pcm_lib_free_pages(substream);
 175 }
 176
 177 static int dmaengine_pcm_trigger(struct snd_soc_component *component,
 178                                  struct snd_pcm_substream *substream, int cmd)
 179 {
 180         return snd_dmaengine_pcm_trigger(substream, cmd);
 181 }
 182
 183 static struct dma_chan *dmaengine_pcm_compat_request_channel(
 184         struct snd_soc_component *component,
 185         struct snd_soc_pcm_runtime *rtd,
 186         struct snd_pcm_substream *substream)
 187 {
 188         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 189         struct snd_dmaengine_dai_dma_data *dma_data;
 190         dma_filter_fn fn = NULL;
 191
 192         dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 193
 194         if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
 195                 return pcm->chan[0];
 196
 197         if (pcm->config && pcm->config->compat_request_channel)
 198                 return pcm->config->compat_request_channel(rtd, substream);
 199
 200         if (pcm->config)
 201                 fn = pcm->config->compat_filter_fn;
 202
 203         return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data);
 204 }
 205
 206 static bool dmaengine_pcm_can_report_residue(struct device *dev,
 207         struct dma_chan *chan)
 208 {
 209         struct dma_slave_caps dma_caps;
 210         int ret;
 211
 212         ret = dma_get_slave_caps(chan, &dma_caps);
 213         if (ret != 0) {
 214                 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n",
 215                          ret);
 216                 return false;
 217         }
 218
 219         if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR)
 220                 return false;
 221
 222         return true;
 223 }
 224
 225 static int dmaengine_pcm_new(struct snd_soc_component *component,
 226                              struct snd_soc_pcm_runtime *rtd)
 227 {
 228         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 229         const struct snd_dmaengine_pcm_config *config = pcm->config;
 230         struct device *dev = component->dev;
 231         struct snd_pcm_substream *substream;
 232         size_t prealloc_buffer_size;
 233         size_t max_buffer_size;
 234         unsigned int i;
 235
 236         if (config && config->prealloc_buffer_size) {
 237                 prealloc_buffer_size = config->prealloc_buffer_size;
 238                 max_buffer_size = config->pcm_hardware->buffer_bytes_max;
 239         } else {
 240                 prealloc_buffer_size = 512 * 1024;
 241                 max_buffer_size = SIZE_MAX;
 242         }
 243
 244         for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
 245                 substream = rtd->pcm->streams[i].substream;
 246                 if (!substream)
 247                         continue;
 248
 249                 if (!pcm->chan[i] && config && config->chan_names[i])
 250                         pcm->chan[i] = dma_request_slave_channel(dev,
 251                                 config->chan_names[i]);
 252
 253                 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
 254                         pcm->chan[i] = dmaengine_pcm_compat_request_channel(
 255                                 component, rtd, substream);
 256                 }
 257
 258                 if (!pcm->chan[i]) {
 259                         dev_err(component->dev,
 260                                 "Missing dma channel for stream: %d\n", i);
 261                         return -EINVAL;
 262                 }
 263
 264                 snd_pcm_lib_preallocate_pages(substream,
 265                                 SNDRV_DMA_TYPE_DEV_IRAM,
 266                                 dmaengine_dma_dev(pcm, substream),
 267                                 prealloc_buffer_size,
 268                                 max_buffer_size);
 269
 270                 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
 271                         pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
 272
 273                 if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
 274                         strscpy_pad(rtd->pcm->streams[i].pcm->name,
 275                                     rtd->pcm->streams[i].pcm->id,
 276                                     sizeof(rtd->pcm->streams[i].pcm->name));
 277                 }
 278         }
 279
 280         return 0;
 281 }
 282
 283 static snd_pcm_uframes_t dmaengine_pcm_pointer(
 284         struct snd_soc_component *component,
 285         struct snd_pcm_substream *substream)
 286 {
 287         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 288
 289         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
 290                 return snd_dmaengine_pcm_pointer_no_residue(substream);
 291         else
 292                 return snd_dmaengine_pcm_pointer(substream);
 293 }
 294
 295 static int dmaengine_copy_user(struct snd_soc_component *component,
 296                                struct snd_pcm_substream *substream,
 297                                int channel, unsigned long hwoff,
 298                                void __user *buf, unsigned long bytes)
 299 {
 300         struct snd_pcm_runtime *runtime = substream->runtime;
 301         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 302         int (*process)(struct snd_pcm_substream *substream,
 303                        int channel, unsigned long hwoff,
 304                        void *buf, unsigned long bytes) = pcm->config->process;
 305         bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 306         void *dma_ptr = runtime->dma_area + hwoff +
 307                         channel * (runtime->dma_bytes / runtime->channels);
 308         int ret;
 309
 310         if (is_playback)
 311                 if (copy_from_user(dma_ptr, buf, bytes))
 312                         return -EFAULT;
 313
 314         if (process) {
 315                 ret = process(substream, channel, hwoff, (__force void *)buf, bytes);
 316                 if (ret < 0)
 317                         return ret;
 318         }
 319
 320         if (!is_playback)
 321                 if (copy_to_user(buf, dma_ptr, bytes))
 322                         return -EFAULT;
 323
 324         return 0;
 325 }
 326
 327 static const struct snd_soc_component_driver dmaengine_pcm_component = {
 328         .name           = SND_DMAENGINE_PCM_DRV_NAME,
 329         .probe_order    = SND_SOC_COMP_ORDER_LATE,
 330         .open           = dmaengine_pcm_open,
 331         .close          = dmaengine_pcm_close,
 332         .ioctl          = snd_soc_pcm_lib_ioctl,
 333         .hw_params      = dmaengine_pcm_hw_params,
 334         .hw_free        = dmaengine_pcm_hw_free,
 335         .trigger        = dmaengine_pcm_trigger,
 336         .pointer        = dmaengine_pcm_pointer,
 337         .pcm_construct  = dmaengine_pcm_new,
 338 };
 339
 340 static const struct snd_soc_component_driver dmaengine_pcm_component_process = {
 341         .name           = SND_DMAENGINE_PCM_DRV_NAME,
 342         .probe_order    = SND_SOC_COMP_ORDER_LATE,
 343         .open           = dmaengine_pcm_open,
 344         .close          = dmaengine_pcm_close,
 345         .ioctl          = snd_soc_pcm_lib_ioctl,
 346         .hw_params      = dmaengine_pcm_hw_params,
 347         .hw_free        = dmaengine_pcm_hw_free,
 348         .trigger        = dmaengine_pcm_trigger,
 349         .pointer        = dmaengine_pcm_pointer,
 350         .copy_user      = dmaengine_copy_user,
 351         .pcm_construct  = dmaengine_pcm_new,
 352 };
 353
 354 static const char * const dmaengine_pcm_dma_channel_names[] = {
 355         [SNDRV_PCM_STREAM_PLAYBACK] = "tx",
 356         [SNDRV_PCM_STREAM_CAPTURE] = "rx",
 357 };
 358
 359 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
 360         struct device *dev, const struct snd_dmaengine_pcm_config *config)
 361 {
 362         unsigned int i;
 363         const char *name;
 364         struct dma_chan *chan;
 365
 366         if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node &&
 367             !(config && config->dma_dev && config->dma_dev->of_node)))
 368                 return 0;
 369
 370         if (config && config->dma_dev) {
 371                 /*
 372                  * If this warning is seen, it probably means that your Linux
 373                  * device structure does not match your HW device structure.
 374                  * It would be best to refactor the Linux device structure to
 375                  * correctly match the HW structure.
 376                  */
 377                 dev_warn(dev, "DMA channels sourced from device %s",
 378                          dev_name(config->dma_dev));
 379                 dev = config->dma_dev;
 380         }
 381
 382         for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
 383              i++) {
 384                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 385                         name = "rx-tx";
 386                 else
 387                         name = dmaengine_pcm_dma_channel_names[i];
 388                 if (config && config->chan_names[i])
 389                         name = config->chan_names[i];
 390                 chan = dma_request_slave_channel_reason(dev, name);
 391                 if (IS_ERR(chan)) {
 392                         if (PTR_ERR(chan) == -EPROBE_DEFER)
 393                                 return -EPROBE_DEFER;
 394                         pcm->chan[i] = NULL;
 395                 } else {
 396                         pcm->chan[i] = chan;
 397                 }
 398                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 399                         break;
 400         }
 401
 402         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 403                 pcm->chan[1] = pcm->chan[0];
 404
 405         return 0;
 406 }
 407
 408 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm)
 409 {
 410         unsigned int i;
 411
 412         for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
 413              i++) {
 414                 if (!pcm->chan[i])
 415                         continue;
 416                 dma_release_channel(pcm->chan[i]);
 417                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 418                         break;
 419         }
 420 }
 421
 422 /**
 423  * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
 424  * @dev: The parent device for the PCM device
 425  * @config: Platform specific PCM configuration
 426  * @flags: Platform specific quirks
 427  */
 428 int snd_dmaengine_pcm_register(struct device *dev,
 429         const struct snd_dmaengine_pcm_config *config, unsigned int flags)
 430 {
 431         struct dmaengine_pcm *pcm;
 432         int ret;
 433
 434         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 435         if (!pcm)
 436                 return -ENOMEM;
 437
 438 #ifdef CONFIG_DEBUG_FS
 439         pcm->component.debugfs_prefix = "dma";
 440 #endif
 441         pcm->config = config;
 442         pcm->flags = flags;
 443
 444         ret = dmaengine_pcm_request_chan_of(pcm, dev, config);
 445         if (ret)
 446                 goto err_free_dma;
 447
 448         if (config && config->process)
 449                 ret = snd_soc_add_component(dev, &pcm->component,
 450                                             &dmaengine_pcm_component_process,
 451                                             NULL, 0);
 452         else
 453                 ret = snd_soc_add_component(dev, &pcm->component,
 454                                             &dmaengine_pcm_component, NULL, 0);
 455         if (ret)
 456                 goto err_free_dma;
 457
 458         return 0;
 459
 460 err_free_dma:
 461         dmaengine_pcm_release_chan(pcm);
 462         kfree(pcm);
 463         return ret;
 464 }
 465 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
 466
 467 /**
 468  * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
 469  * @dev: Parent device the PCM was register with
 470  *
 471  * Removes a dmaengine based PCM device previously registered with
 472  * snd_dmaengine_pcm_register.
 473  */
 474 void snd_dmaengine_pcm_unregister(struct device *dev)
 475 {
 476         struct snd_soc_component *component;
 477         struct dmaengine_pcm *pcm;
 478
 479         component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME);
 480         if (!component)
 481                 return;
 482
 483         pcm = soc_component_to_pcm(component);
 484
 485         snd_soc_unregister_component(dev);
 486         dmaengine_pcm_release_chan(pcm);
 487         kfree(pcm);
 488 }
 489 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
 490
 491 MODULE_LICENSE("GPL");