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 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm,
  25         struct snd_pcm_substream *substream)
  26 {
  27         if (!pcm->chan[substream->stream])
  28                 return NULL;
  29
  30         return pcm->chan[substream->stream]->device->dev;
  31 }
  32
  33 /**
  34  * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback
  35  * @substream: PCM substream
  36  * @params: hw_params
  37  * @slave_config: DMA slave config to prepare
  38  *
  39  * This function can be used as a generic prepare_slave_config callback for
  40  * platforms which make use of the snd_dmaengine_dai_dma_data struct for their
  41  * DAI DMA data. Internally the function will first call
  42  * snd_hwparams_to_dma_slave_config to fill in the slave config based on the
  43  * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the
  44  * remaining fields based on the DAI DMA data.
  45  */
  46 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
  47         struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
  48 {
  49         struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  50         struct snd_dmaengine_dai_dma_data *dma_data;
  51         int ret;
  52
  53         if (rtd->num_cpus > 1) {
  54                 dev_err(rtd->dev,
  55                         "%s doesn't support Multi CPU yet\n", __func__);
  56                 return -EINVAL;
  57         }
  58
  59         dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
  60
  61         ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
  62         if (ret)
  63                 return ret;
  64
  65         snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data,
  66                 slave_config);
  67
  68         return 0;
  69 }
  70 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);
  71
  72 static int dmaengine_pcm_hw_params(struct snd_soc_component *component,
  73                                    struct snd_pcm_substream *substream,
  74                                    struct snd_pcm_hw_params *params)
  75 {
  76         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
  77         struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
  78         int (*prepare_slave_config)(struct snd_pcm_substream *substream,
  79                         struct snd_pcm_hw_params *params,
  80                         struct dma_slave_config *slave_config);
  81         struct dma_slave_config slave_config;
  82
  83         memset(&slave_config, 0, sizeof(slave_config));
  84
  85         if (!pcm->config)
  86                 prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config;
  87         else
  88                 prepare_slave_config = pcm->config->prepare_slave_config;
  89
  90         if (prepare_slave_config) {
  91                 int ret = prepare_slave_config(substream, params, &slave_config);
  92                 if (ret)
  93                         return ret;
  94
  95                 ret = dmaengine_slave_config(chan, &slave_config);
  96                 if (ret)
  97                         return ret;
  98         }
  99
 100         return 0;
 101 }
 102
 103 static int
 104 dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component,
 105                                    struct snd_pcm_substream *substream)
 106 {
 107         struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 108         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 109         struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
 110         struct dma_chan *chan = pcm->chan[substream->stream];
 111         struct snd_dmaengine_dai_dma_data *dma_data;
 112         struct snd_pcm_hardware hw;
 113
 114         if (rtd->num_cpus > 1) {
 115                 dev_err(rtd->dev,
 116                         "%s doesn't support Multi CPU yet\n", __func__);
 117                 return -EINVAL;
 118         }
 119
 120         if (pcm->config && pcm->config->pcm_hardware)
 121                 return snd_soc_set_runtime_hwparams(substream,
 122                                 pcm->config->pcm_hardware);
 123
 124         dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
 125
 126         memset(&hw, 0, sizeof(hw));
 127         hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
 128                         SNDRV_PCM_INFO_INTERLEAVED;
 129         hw.periods_min = 2;
 130         hw.periods_max = UINT_MAX;
 131         hw.period_bytes_min = 256;
 132         hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
 133         hw.buffer_bytes_max = SIZE_MAX;
 134         hw.fifo_size = dma_data->fifo_size;
 135
 136         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
 137                 hw.info |= SNDRV_PCM_INFO_BATCH;
 138
 139         /**
 140          * FIXME: Remove the return value check to align with the code
 141          * before adding snd_dmaengine_pcm_refine_runtime_hwparams
 142          * function.
 143          */
 144         snd_dmaengine_pcm_refine_runtime_hwparams(substream,
 145                                                   dma_data,
 146                                                   &hw,
 147                                                   chan);
 148
 149         return snd_soc_set_runtime_hwparams(substream, &hw);
 150 }
 151
 152 static int dmaengine_pcm_open(struct snd_soc_component *component,
 153                               struct snd_pcm_substream *substream)
 154 {
 155         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 156         struct dma_chan *chan = pcm->chan[substream->stream];
 157         int ret;
 158
 159         ret = dmaengine_pcm_set_runtime_hwparams(component, substream);
 160         if (ret)
 161                 return ret;
 162
 163         return snd_dmaengine_pcm_open(substream, chan);
 164 }
 165
 166 static int dmaengine_pcm_close(struct snd_soc_component *component,
 167                                struct snd_pcm_substream *substream)
 168 {
 169         return snd_dmaengine_pcm_close(substream);
 170 }
 171
 172 static int dmaengine_pcm_trigger(struct snd_soc_component *component,
 173                                  struct snd_pcm_substream *substream, int cmd)
 174 {
 175         return snd_dmaengine_pcm_trigger(substream, cmd);
 176 }
 177
 178 static struct dma_chan *dmaengine_pcm_compat_request_channel(
 179         struct snd_soc_component *component,
 180         struct snd_soc_pcm_runtime *rtd,
 181         struct snd_pcm_substream *substream)
 182 {
 183         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 184         struct snd_dmaengine_dai_dma_data *dma_data;
 185         dma_filter_fn fn = NULL;
 186
 187         if (rtd->num_cpus > 1) {
 188                 dev_err(rtd->dev,
 189                         "%s doesn't support Multi CPU yet\n", __func__);
 190                 return NULL;
 191         }
 192
 193         dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
 194
 195         if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
 196                 return pcm->chan[0];
 197
 198         if (pcm->config && pcm->config->compat_request_channel)
 199                 return pcm->config->compat_request_channel(rtd, substream);
 200
 201         if (pcm->config)
 202                 fn = pcm->config->compat_filter_fn;
 203
 204         return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data);
 205 }
 206
 207 static bool dmaengine_pcm_can_report_residue(struct device *dev,
 208         struct dma_chan *chan)
 209 {
 210         struct dma_slave_caps dma_caps;
 211         int ret;
 212
 213         ret = dma_get_slave_caps(chan, &dma_caps);
 214         if (ret != 0) {
 215                 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n",
 216                          ret);
 217                 return false;
 218         }
 219
 220         if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR)
 221                 return false;
 222
 223         return true;
 224 }
 225
 226 static int dmaengine_pcm_new(struct snd_soc_component *component,
 227                              struct snd_soc_pcm_runtime *rtd)
 228 {
 229         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 230         const struct snd_dmaengine_pcm_config *config = pcm->config;
 231         struct device *dev = component->dev;
 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_each_pcm_streams(i) {
 245                 struct snd_pcm_substream *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_set_managed_buffer(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         .hw_params      = dmaengine_pcm_hw_params,
 333         .trigger        = dmaengine_pcm_trigger,
 334         .pointer        = dmaengine_pcm_pointer,
 335         .pcm_construct  = dmaengine_pcm_new,
 336 };
 337
 338 static const struct snd_soc_component_driver dmaengine_pcm_component_process = {
 339         .name           = SND_DMAENGINE_PCM_DRV_NAME,
 340         .probe_order    = SND_SOC_COMP_ORDER_LATE,
 341         .open           = dmaengine_pcm_open,
 342         .close          = dmaengine_pcm_close,
 343         .hw_params      = dmaengine_pcm_hw_params,
 344         .trigger        = dmaengine_pcm_trigger,
 345         .pointer        = dmaengine_pcm_pointer,
 346         .copy_user      = dmaengine_copy_user,
 347         .pcm_construct  = dmaengine_pcm_new,
 348 };
 349
 350 static const char * const dmaengine_pcm_dma_channel_names[] = {
 351         [SNDRV_PCM_STREAM_PLAYBACK] = "tx",
 352         [SNDRV_PCM_STREAM_CAPTURE] = "rx",
 353 };
 354
 355 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
 356         struct device *dev, const struct snd_dmaengine_pcm_config *config)
 357 {
 358         unsigned int i;
 359         const char *name;
 360         struct dma_chan *chan;
 361
 362         if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node &&
 363             !(config && config->dma_dev && config->dma_dev->of_node)))
 364                 return 0;
 365
 366         if (config && config->dma_dev) {
 367                 /*
 368                  * If this warning is seen, it probably means that your Linux
 369                  * device structure does not match your HW device structure.
 370                  * It would be best to refactor the Linux device structure to
 371                  * correctly match the HW structure.
 372                  */
 373                 dev_warn(dev, "DMA channels sourced from device %s",
 374                          dev_name(config->dma_dev));
 375                 dev = config->dma_dev;
 376         }
 377
 378         for_each_pcm_streams(i) {
 379                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 380                         name = "rx-tx";
 381                 else
 382                         name = dmaengine_pcm_dma_channel_names[i];
 383                 if (config && config->chan_names[i])
 384                         name = config->chan_names[i];
 385                 chan = dma_request_chan(dev, name);
 386                 if (IS_ERR(chan)) {
 387                         /*
 388                          * Only report probe deferral errors, channels
 389                          * might not be present for devices that
 390                          * support only TX or only RX.
 391                          */
 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_each_pcm_streams(i) {
 413                 if (!pcm->chan[i])
 414                         continue;
 415                 dma_release_channel(pcm->chan[i]);
 416                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 417                         break;
 418         }
 419 }
 420
 421 /**
 422  * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
 423  * @dev: The parent device for the PCM device
 424  * @config: Platform specific PCM configuration
 425  * @flags: Platform specific quirks
 426  */
 427 int snd_dmaengine_pcm_register(struct device *dev,
 428         const struct snd_dmaengine_pcm_config *config, unsigned int flags)
 429 {
 430         const struct snd_soc_component_driver *driver;
 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                 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");