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         int ret;
  83
  84         memset(&slave_config, 0, sizeof(slave_config));
  85
  86         if (!pcm->config)
  87                 prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config;
  88         else
  89                 prepare_slave_config = pcm->config->prepare_slave_config;
  90
  91         if (prepare_slave_config) {
  92                 ret = prepare_slave_config(substream, params, &slave_config);
  93                 if (ret)
  94                         return ret;
  95
  96                 ret = dmaengine_slave_config(chan, &slave_config);
  97                 if (ret)
  98                         return ret;
  99         }
 100
 101         return 0;
 102 }
 103
 104 static int
 105 dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component,
 106                                    struct snd_pcm_substream *substream)
 107 {
 108         struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 109         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 110         struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
 111         struct dma_chan *chan = pcm->chan[substream->stream];
 112         struct snd_dmaengine_dai_dma_data *dma_data;
 113         struct snd_pcm_hardware hw;
 114
 115         if (rtd->num_cpus > 1) {
 116                 dev_err(rtd->dev,
 117                         "%s doesn't support Multi CPU yet\n", __func__);
 118                 return -EINVAL;
 119         }
 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(asoc_rtd_to_cpu(rtd, 0), 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_trigger(struct snd_soc_component *component,
 174                                  struct snd_pcm_substream *substream, int cmd)
 175 {
 176         return snd_dmaengine_pcm_trigger(substream, cmd);
 177 }
 178
 179 static struct dma_chan *dmaengine_pcm_compat_request_channel(
 180         struct snd_soc_component *component,
 181         struct snd_soc_pcm_runtime *rtd,
 182         struct snd_pcm_substream *substream)
 183 {
 184         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 185         struct snd_dmaengine_dai_dma_data *dma_data;
 186         dma_filter_fn fn = NULL;
 187
 188         if (rtd->num_cpus > 1) {
 189                 dev_err(rtd->dev,
 190                         "%s doesn't support Multi CPU yet\n", __func__);
 191                 return NULL;
 192         }
 193
 194         dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), 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_each_pcm_streams(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_set_managed_buffer(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         .hw_params      = dmaengine_pcm_hw_params,
 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         .hw_params      = dmaengine_pcm_hw_params,
 346         .trigger        = dmaengine_pcm_trigger,
 347         .pointer        = dmaengine_pcm_pointer,
 348         .copy_user      = dmaengine_copy_user,
 349         .pcm_construct  = dmaengine_pcm_new,
 350 };
 351
 352 static const char * const dmaengine_pcm_dma_channel_names[] = {
 353         [SNDRV_PCM_STREAM_PLAYBACK] = "tx",
 354         [SNDRV_PCM_STREAM_CAPTURE] = "rx",
 355 };
 356
 357 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
 358         struct device *dev, const struct snd_dmaengine_pcm_config *config)
 359 {
 360         unsigned int i;
 361         const char *name;
 362         struct dma_chan *chan;
 363
 364         if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node &&
 365             !(config && config->dma_dev && config->dma_dev->of_node)))
 366                 return 0;
 367
 368         if (config && config->dma_dev) {
 369                 /*
 370                  * If this warning is seen, it probably means that your Linux
 371                  * device structure does not match your HW device structure.
 372                  * It would be best to refactor the Linux device structure to
 373                  * correctly match the HW structure.
 374                  */
 375                 dev_warn(dev, "DMA channels sourced from device %s",
 376                          dev_name(config->dma_dev));
 377                 dev = config->dma_dev;
 378         }
 379
 380         for_each_pcm_streams(i) {
 381                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 382                         name = "rx-tx";
 383                 else
 384                         name = dmaengine_pcm_dma_channel_names[i];
 385                 if (config && config->chan_names[i])
 386                         name = config->chan_names[i];
 387                 chan = dma_request_chan(dev, name);
 388                 if (IS_ERR(chan)) {
 389                         /*
 390                          * Only report probe deferral errors, channels
 391                          * might not be present for devices that
 392                          * support only TX or only RX.
 393                          */
 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_each_pcm_streams(i) {
 415                 if (!pcm->chan[i])
 416                         continue;
 417                 dma_release_channel(pcm->chan[i]);
 418                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 419                         break;
 420         }
 421 }
 422
 423 /**
 424  * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
 425  * @dev: The parent device for the PCM device
 426  * @config: Platform specific PCM configuration
 427  * @flags: Platform specific quirks
 428  */
 429 int snd_dmaengine_pcm_register(struct device *dev,
 430         const struct snd_dmaengine_pcm_config *config, unsigned int flags)
 431 {
 432         const struct snd_soc_component_driver *driver;
 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                 driver = &dmaengine_pcm_component_process;
 452         else
 453                 driver = &dmaengine_pcm_component;
 454
 455         ret = snd_soc_component_initialize(&pcm->component, driver, dev);
 456         if (ret)
 457                 goto err_free_dma;
 458
 459         ret = snd_soc_add_component(&pcm->component, NULL, 0);
 460         if (ret)
 461                 goto err_free_dma;
 462
 463         return 0;
 464
 465 err_free_dma:
 466         dmaengine_pcm_release_chan(pcm);
 467         kfree(pcm);
 468         return ret;
 469 }
 470 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
 471
 472 /**
 473  * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
 474  * @dev: Parent device the PCM was register with
 475  *
 476  * Removes a dmaengine based PCM device previously registered with
 477  * snd_dmaengine_pcm_register.
 478  */
 479 void snd_dmaengine_pcm_unregister(struct device *dev)
 480 {
 481         struct snd_soc_component *component;
 482         struct dmaengine_pcm *pcm;
 483
 484         component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME);
 485         if (!component)
 486                 return;
 487
 488         pcm = soc_component_to_pcm(component);
 489
 490         snd_soc_unregister_component_by_driver(dev, component->driver);
 491         dmaengine_pcm_release_chan(pcm);
 492         kfree(pcm);
 493 }
 494 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
 495
 496 MODULE_LICENSE("GPL");