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 static unsigned int prealloc_buffer_size_kbytes = 512;
  19 module_param(prealloc_buffer_size_kbytes, uint, 0444);
  20 MODULE_PARM_DESC(prealloc_buffer_size_kbytes, "Preallocate DMA buffer size (KB).");
  21
  22 /*
  23  * The platforms dmaengine driver does not support reporting the amount of
  24  * bytes that are still left to transfer.
  25  */
  26 #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31)
  27
  28 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm,
  29         struct snd_pcm_substream *substream)
  30 {
  31         if (!pcm->chan[substream->stream])
  32                 return NULL;
  33
  34         return pcm->chan[substream->stream]->device->dev;
  35 }
  36
  37 /**
  38  * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback
  39  * @substream: PCM substream
  40  * @params: hw_params
  41  * @slave_config: DMA slave config to prepare
  42  *
  43  * This function can be used as a generic prepare_slave_config callback for
  44  * platforms which make use of the snd_dmaengine_dai_dma_data struct for their
  45  * DAI DMA data. Internally the function will first call
  46  * snd_hwparams_to_dma_slave_config to fill in the slave config based on the
  47  * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the
  48  * remaining fields based on the DAI DMA data.
  49  */
  50 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
  51         struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
  52 {
  53         struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  54         struct snd_dmaengine_dai_dma_data *dma_data;
  55         int ret;
  56
  57         if (rtd->num_cpus > 1) {
  58                 dev_err(rtd->dev,
  59                         "%s doesn't support Multi CPU yet\n", __func__);
  60                 return -EINVAL;
  61         }
  62
  63         dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
  64
  65         ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
  66         if (ret)
  67                 return ret;
  68
  69         snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data,
  70                 slave_config);
  71
  72         return 0;
  73 }
  74 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);
  75
  76 static int dmaengine_pcm_hw_params(struct snd_soc_component *component,
  77                                    struct snd_pcm_substream *substream,
  78                                    struct snd_pcm_hw_params *params)
  79 {
  80         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
  81         struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
  82         struct dma_slave_config slave_config;
  83         int ret;
  84
  85         if (!pcm->config->prepare_slave_config)
  86                 return 0;
  87
  88         memset(&slave_config, 0, sizeof(slave_config));
  89
  90         ret = pcm->config->prepare_slave_config(substream, params, &slave_config);
  91         if (ret)
  92                 return ret;
  93
  94         return dmaengine_slave_config(chan, &slave_config);
  95 }
  96
  97 static int
  98 dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component,
  99                                    struct snd_pcm_substream *substream)
 100 {
 101         struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 102         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 103         struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
 104         struct dma_chan *chan = pcm->chan[substream->stream];
 105         struct snd_dmaengine_dai_dma_data *dma_data;
 106         struct snd_pcm_hardware hw;
 107
 108         if (rtd->num_cpus > 1) {
 109                 dev_err(rtd->dev,
 110                         "%s doesn't support Multi CPU yet\n", __func__);
 111                 return -EINVAL;
 112         }
 113
 114         if (pcm->config->pcm_hardware)
 115                 return snd_soc_set_runtime_hwparams(substream,
 116                                 pcm->config->pcm_hardware);
 117
 118         dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
 119
 120         memset(&hw, 0, sizeof(hw));
 121         hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
 122                         SNDRV_PCM_INFO_INTERLEAVED;
 123         hw.periods_min = 2;
 124         hw.periods_max = UINT_MAX;
 125         hw.period_bytes_min = dma_data->maxburst * DMA_SLAVE_BUSWIDTH_8_BYTES;
 126         if (!hw.period_bytes_min)
 127                 hw.period_bytes_min = 256;
 128         hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
 129         hw.buffer_bytes_max = SIZE_MAX;
 130         hw.fifo_size = dma_data->fifo_size;
 131
 132         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
 133                 hw.info |= SNDRV_PCM_INFO_BATCH;
 134
 135         /**
 136          * FIXME: Remove the return value check to align with the code
 137          * before adding snd_dmaengine_pcm_refine_runtime_hwparams
 138          * function.
 139          */
 140         snd_dmaengine_pcm_refine_runtime_hwparams(substream,
 141                                                   dma_data,
 142                                                   &hw,
 143                                                   chan);
 144
 145         return snd_soc_set_runtime_hwparams(substream, &hw);
 146 }
 147
 148 static int dmaengine_pcm_open(struct snd_soc_component *component,
 149                               struct snd_pcm_substream *substream)
 150 {
 151         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 152         struct dma_chan *chan = pcm->chan[substream->stream];
 153         int ret;
 154
 155         ret = dmaengine_pcm_set_runtime_hwparams(component, substream);
 156         if (ret)
 157                 return ret;
 158
 159         return snd_dmaengine_pcm_open(substream, chan);
 160 }
 161
 162 static int dmaengine_pcm_close(struct snd_soc_component *component,
 163                                struct snd_pcm_substream *substream)
 164 {
 165         return snd_dmaengine_pcm_close(substream);
 166 }
 167
 168 static int dmaengine_pcm_trigger(struct snd_soc_component *component,
 169                                  struct snd_pcm_substream *substream, int cmd)
 170 {
 171         return snd_dmaengine_pcm_trigger(substream, cmd);
 172 }
 173
 174 static struct dma_chan *dmaengine_pcm_compat_request_channel(
 175         struct snd_soc_component *component,
 176         struct snd_soc_pcm_runtime *rtd,
 177         struct snd_pcm_substream *substream)
 178 {
 179         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 180         struct snd_dmaengine_dai_dma_data *dma_data;
 181
 182         if (rtd->num_cpus > 1) {
 183                 dev_err(rtd->dev,
 184                         "%s doesn't support Multi CPU yet\n", __func__);
 185                 return NULL;
 186         }
 187
 188         dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
 189
 190         if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
 191                 return pcm->chan[0];
 192
 193         if (pcm->config->compat_request_channel)
 194                 return pcm->config->compat_request_channel(rtd, substream);
 195
 196         return snd_dmaengine_pcm_request_channel(pcm->config->compat_filter_fn,
 197                                                  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         size_t prealloc_buffer_size;
 226         size_t max_buffer_size;
 227         unsigned int i;
 228
 229         if (config->prealloc_buffer_size)
 230                 prealloc_buffer_size = config->prealloc_buffer_size;
 231         else
 232                 prealloc_buffer_size = prealloc_buffer_size_kbytes * 1024;
 233
 234         if (config->pcm_hardware && config->pcm_hardware->buffer_bytes_max)
 235                 max_buffer_size = config->pcm_hardware->buffer_bytes_max;
 236         else
 237                 max_buffer_size = SIZE_MAX;
 238
 239         for_each_pcm_streams(i) {
 240                 struct snd_pcm_substream *substream = rtd->pcm->streams[i].substream;
 241                 if (!substream)
 242                         continue;
 243
 244                 if (!pcm->chan[i] && config->chan_names[i])
 245                         pcm->chan[i] = dma_request_slave_channel(dev,
 246                                 config->chan_names[i]);
 247
 248                 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
 249                         pcm->chan[i] = dmaengine_pcm_compat_request_channel(
 250                                 component, rtd, substream);
 251                 }
 252
 253                 if (!pcm->chan[i]) {
 254                         dev_err(component->dev,
 255                                 "Missing dma channel for stream: %d\n", i);
 256                         return -EINVAL;
 257                 }
 258
 259                 snd_pcm_set_managed_buffer(substream,
 260                                 SNDRV_DMA_TYPE_DEV_IRAM,
 261                                 dmaengine_dma_dev(pcm, substream),
 262                                 prealloc_buffer_size,
 263                                 max_buffer_size);
 264
 265                 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
 266                         pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
 267
 268                 if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
 269                         strscpy_pad(rtd->pcm->streams[i].pcm->name,
 270                                     rtd->pcm->streams[i].pcm->id,
 271                                     sizeof(rtd->pcm->streams[i].pcm->name));
 272                 }
 273         }
 274
 275         return 0;
 276 }
 277
 278 static snd_pcm_uframes_t dmaengine_pcm_pointer(
 279         struct snd_soc_component *component,
 280         struct snd_pcm_substream *substream)
 281 {
 282         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 283
 284         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
 285                 return snd_dmaengine_pcm_pointer_no_residue(substream);
 286         else
 287                 return snd_dmaengine_pcm_pointer(substream);
 288 }
 289
 290 static int dmaengine_copy_user(struct snd_soc_component *component,
 291                                struct snd_pcm_substream *substream,
 292                                int channel, unsigned long hwoff,
 293                                void __user *buf, unsigned long bytes)
 294 {
 295         struct snd_pcm_runtime *runtime = substream->runtime;
 296         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 297         int (*process)(struct snd_pcm_substream *substream,
 298                        int channel, unsigned long hwoff,
 299                        void *buf, unsigned long bytes) = pcm->config->process;
 300         bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 301         void *dma_ptr = runtime->dma_area + hwoff +
 302                         channel * (runtime->dma_bytes / runtime->channels);
 303
 304         if (is_playback)
 305                 if (copy_from_user(dma_ptr, buf, bytes))
 306                         return -EFAULT;
 307
 308         if (process) {
 309                 int 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->dma_dev && config->dma_dev->of_node)))
 358                 return 0;
 359
 360         if (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_each_pcm_streams(i) {
 373                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 374                         name = "rx-tx";
 375                 else
 376                         name = dmaengine_pcm_dma_channel_names[i];
 377                 if (config->chan_names[i])
 378                         name = config->chan_names[i];
 379                 chan = dma_request_chan(dev, name);
 380                 if (IS_ERR(chan)) {
 381                         /*
 382                          * Only report probe deferral errors, channels
 383                          * might not be present for devices that
 384                          * support only TX or only RX.
 385                          */
 386                         if (PTR_ERR(chan) == -EPROBE_DEFER)
 387                                 return -EPROBE_DEFER;
 388                         pcm->chan[i] = NULL;
 389                 } else {
 390                         pcm->chan[i] = chan;
 391                 }
 392                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 393                         break;
 394         }
 395
 396         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 397                 pcm->chan[1] = pcm->chan[0];
 398
 399         return 0;
 400 }
 401
 402 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm)
 403 {
 404         unsigned int i;
 405
 406         for_each_pcm_streams(i) {
 407                 if (!pcm->chan[i])
 408                         continue;
 409                 dma_release_channel(pcm->chan[i]);
 410                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 411                         break;
 412         }
 413 }
 414
 415 static const struct snd_dmaengine_pcm_config snd_dmaengine_pcm_default_config = {
 416         .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
 417 };
 418
 419 /**
 420  * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
 421  * @dev: The parent device for the PCM device
 422  * @config: Platform specific PCM configuration
 423  * @flags: Platform specific quirks
 424  */
 425 int snd_dmaengine_pcm_register(struct device *dev,
 426         const struct snd_dmaengine_pcm_config *config, unsigned int flags)
 427 {
 428         const struct snd_soc_component_driver *driver;
 429         struct dmaengine_pcm *pcm;
 430         int ret;
 431
 432         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 433         if (!pcm)
 434                 return -ENOMEM;
 435
 436 #ifdef CONFIG_DEBUG_FS
 437         pcm->component.debugfs_prefix = "dma";
 438 #endif
 439         if (!config)
 440                 config = &snd_dmaengine_pcm_default_config;
 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->process)
 449                 driver = &dmaengine_pcm_component_process;
 450         else
 451                 driver = &dmaengine_pcm_component;
 452
 453         ret = snd_soc_component_initialize(&pcm->component, driver, dev);
 454         if (ret)
 455                 goto err_free_dma;
 456
 457         ret = snd_soc_add_component(&pcm->component, NULL, 0);
 458         if (ret)
 459                 goto err_free_dma;
 460
 461         return 0;
 462
 463 err_free_dma:
 464         dmaengine_pcm_release_chan(pcm);
 465         kfree(pcm);
 466         return ret;
 467 }
 468 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
 469
 470 /**
 471  * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
 472  * @dev: Parent device the PCM was register with
 473  *
 474  * Removes a dmaengine based PCM device previously registered with
 475  * snd_dmaengine_pcm_register.
 476  */
 477 void snd_dmaengine_pcm_unregister(struct device *dev)
 478 {
 479         struct snd_soc_component *component;
 480         struct dmaengine_pcm *pcm;
 481
 482         component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME);
 483         if (!component)
 484                 return;
 485
 486         pcm = soc_component_to_pcm(component);
 487
 488         snd_soc_unregister_component_by_driver(dev, component->driver);
 489         dmaengine_pcm_release_chan(pcm);
 490         kfree(pcm);
 491 }
 492 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
 493
 494 MODULE_LICENSE("GPL");