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