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         if (rtd->num_cpus > 1) {
  66                 dev_err(rtd->dev,
  67                         "%s doesn't support Multi CPU yet\n", __func__);
  68                 return -EINVAL;
  69         }
  70
  71         dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
  72
  73         ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
  74         if (ret)
  75                 return ret;
  76
  77         snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data,
  78                 slave_config);
  79
  80         return 0;
  81 }
  82 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);
  83
  84 static int dmaengine_pcm_hw_params(struct snd_soc_component *component,
  85                                    struct snd_pcm_substream *substream,
  86                                    struct snd_pcm_hw_params *params)
  87 {
  88         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
  89         struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
  90         int (*prepare_slave_config)(struct snd_pcm_substream *substream,
  91                         struct snd_pcm_hw_params *params,
  92                         struct dma_slave_config *slave_config);
  93         struct dma_slave_config slave_config;
  94         int ret;
  95
  96         memset(&slave_config, 0, sizeof(slave_config));
  97
  98         if (!pcm->config)
  99                 prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config;
 100         else
 101                 prepare_slave_config = pcm->config->prepare_slave_config;
 102
 103         if (prepare_slave_config) {
 104                 ret = prepare_slave_config(substream, params, &slave_config);
 105                 if (ret)
 106                         return ret;
 107
 108                 ret = dmaengine_slave_config(chan, &slave_config);
 109                 if (ret)
 110                         return ret;
 111         }
 112
 113         return 0;
 114 }
 115
 116 static int
 117 dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component,
 118                                    struct snd_pcm_substream *substream)
 119 {
 120         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 121         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 122         struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
 123         struct dma_chan *chan = pcm->chan[substream->stream];
 124         struct snd_dmaengine_dai_dma_data *dma_data;
 125         struct snd_pcm_hardware hw;
 126
 127         if (rtd->num_cpus > 1) {
 128                 dev_err(rtd->dev,
 129                         "%s doesn't support Multi CPU yet\n", __func__);
 130                 return -EINVAL;
 131         }
 132
 133         if (pcm->config && pcm->config->pcm_hardware)
 134                 return snd_soc_set_runtime_hwparams(substream,
 135                                 pcm->config->pcm_hardware);
 136
 137         dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
 138
 139         memset(&hw, 0, sizeof(hw));
 140         hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
 141                         SNDRV_PCM_INFO_INTERLEAVED;
 142         hw.periods_min = 2;
 143         hw.periods_max = UINT_MAX;
 144         hw.period_bytes_min = 256;
 145         hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
 146         hw.buffer_bytes_max = SIZE_MAX;
 147         hw.fifo_size = dma_data->fifo_size;
 148
 149         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
 150                 hw.info |= SNDRV_PCM_INFO_BATCH;
 151
 152         /**
 153          * FIXME: Remove the return value check to align with the code
 154          * before adding snd_dmaengine_pcm_refine_runtime_hwparams
 155          * function.
 156          */
 157         snd_dmaengine_pcm_refine_runtime_hwparams(substream,
 158                                                   dma_data,
 159                                                   &hw,
 160                                                   chan);
 161
 162         return snd_soc_set_runtime_hwparams(substream, &hw);
 163 }
 164
 165 static int dmaengine_pcm_open(struct snd_soc_component *component,
 166                               struct snd_pcm_substream *substream)
 167 {
 168         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 169         struct dma_chan *chan = pcm->chan[substream->stream];
 170         int ret;
 171
 172         ret = dmaengine_pcm_set_runtime_hwparams(component, substream);
 173         if (ret)
 174                 return ret;
 175
 176         return snd_dmaengine_pcm_open(substream, chan);
 177 }
 178
 179 static int dmaengine_pcm_close(struct snd_soc_component *component,
 180                                struct snd_pcm_substream *substream)
 181 {
 182         return snd_dmaengine_pcm_close(substream);
 183 }
 184
 185 static int dmaengine_pcm_trigger(struct snd_soc_component *component,
 186                                  struct snd_pcm_substream *substream, int cmd)
 187 {
 188         return snd_dmaengine_pcm_trigger(substream, cmd);
 189 }
 190
 191 static struct dma_chan *dmaengine_pcm_compat_request_channel(
 192         struct snd_soc_component *component,
 193         struct snd_soc_pcm_runtime *rtd,
 194         struct snd_pcm_substream *substream)
 195 {
 196         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 197         struct snd_dmaengine_dai_dma_data *dma_data;
 198         dma_filter_fn fn = NULL;
 199
 200         if (rtd->num_cpus > 1) {
 201                 dev_err(rtd->dev,
 202                         "%s doesn't support Multi CPU yet\n", __func__);
 203                 return NULL;
 204         }
 205
 206         dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
 207
 208         if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
 209                 return pcm->chan[0];
 210
 211         if (pcm->config && pcm->config->compat_request_channel)
 212                 return pcm->config->compat_request_channel(rtd, substream);
 213
 214         if (pcm->config)
 215                 fn = pcm->config->compat_filter_fn;
 216
 217         return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data);
 218 }
 219
 220 static bool dmaengine_pcm_can_report_residue(struct device *dev,
 221         struct dma_chan *chan)
 222 {
 223         struct dma_slave_caps dma_caps;
 224         int ret;
 225
 226         ret = dma_get_slave_caps(chan, &dma_caps);
 227         if (ret != 0) {
 228                 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n",
 229                          ret);
 230                 return false;
 231         }
 232
 233         if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR)
 234                 return false;
 235
 236         return true;
 237 }
 238
 239 static int dmaengine_pcm_new(struct snd_soc_component *component,
 240                              struct snd_soc_pcm_runtime *rtd)
 241 {
 242         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 243         const struct snd_dmaengine_pcm_config *config = pcm->config;
 244         struct device *dev = component->dev;
 245         struct snd_pcm_substream *substream;
 246         size_t prealloc_buffer_size;
 247         size_t max_buffer_size;
 248         unsigned int i;
 249
 250         if (config && config->prealloc_buffer_size) {
 251                 prealloc_buffer_size = config->prealloc_buffer_size;
 252                 max_buffer_size = config->pcm_hardware->buffer_bytes_max;
 253         } else {
 254                 prealloc_buffer_size = 512 * 1024;
 255                 max_buffer_size = SIZE_MAX;
 256         }
 257
 258         for_each_pcm_streams(i) {
 259                 substream = rtd->pcm->streams[i].substream;
 260                 if (!substream)
 261                         continue;
 262
 263                 if (!pcm->chan[i] && config && config->chan_names[i])
 264                         pcm->chan[i] = dma_request_slave_channel(dev,
 265                                 config->chan_names[i]);
 266
 267                 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
 268                         pcm->chan[i] = dmaengine_pcm_compat_request_channel(
 269                                 component, rtd, substream);
 270                 }
 271
 272                 if (!pcm->chan[i]) {
 273                         dev_err(component->dev,
 274                                 "Missing dma channel for stream: %d\n", i);
 275                         return -EINVAL;
 276                 }
 277
 278                 snd_pcm_set_managed_buffer(substream,
 279                                 SNDRV_DMA_TYPE_DEV_IRAM,
 280                                 dmaengine_dma_dev(pcm, substream),
 281                                 prealloc_buffer_size,
 282                                 max_buffer_size);
 283
 284                 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
 285                         pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
 286
 287                 if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
 288                         strscpy_pad(rtd->pcm->streams[i].pcm->name,
 289                                     rtd->pcm->streams[i].pcm->id,
 290                                     sizeof(rtd->pcm->streams[i].pcm->name));
 291                 }
 292         }
 293
 294         return 0;
 295 }
 296
 297 static snd_pcm_uframes_t dmaengine_pcm_pointer(
 298         struct snd_soc_component *component,
 299         struct snd_pcm_substream *substream)
 300 {
 301         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 302
 303         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
 304                 return snd_dmaengine_pcm_pointer_no_residue(substream);
 305         else
 306                 return snd_dmaengine_pcm_pointer(substream);
 307 }
 308
 309 static int dmaengine_copy_user(struct snd_soc_component *component,
 310                                struct snd_pcm_substream *substream,
 311                                int channel, unsigned long hwoff,
 312                                void __user *buf, unsigned long bytes)
 313 {
 314         struct snd_pcm_runtime *runtime = substream->runtime;
 315         struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
 316         int (*process)(struct snd_pcm_substream *substream,
 317                        int channel, unsigned long hwoff,
 318                        void *buf, unsigned long bytes) = pcm->config->process;
 319         bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 320         void *dma_ptr = runtime->dma_area + hwoff +
 321                         channel * (runtime->dma_bytes / runtime->channels);
 322         int ret;
 323
 324         if (is_playback)
 325                 if (copy_from_user(dma_ptr, buf, bytes))
 326                         return -EFAULT;
 327
 328         if (process) {
 329                 ret = process(substream, channel, hwoff, (__force void *)buf, bytes);
 330                 if (ret < 0)
 331                         return ret;
 332         }
 333
 334         if (!is_playback)
 335                 if (copy_to_user(buf, dma_ptr, bytes))
 336                         return -EFAULT;
 337
 338         return 0;
 339 }
 340
 341 static const struct snd_soc_component_driver dmaengine_pcm_component = {
 342         .name           = SND_DMAENGINE_PCM_DRV_NAME,
 343         .probe_order    = SND_SOC_COMP_ORDER_LATE,
 344         .open           = dmaengine_pcm_open,
 345         .close          = dmaengine_pcm_close,
 346         .hw_params      = dmaengine_pcm_hw_params,
 347         .trigger        = dmaengine_pcm_trigger,
 348         .pointer        = dmaengine_pcm_pointer,
 349         .pcm_construct  = dmaengine_pcm_new,
 350 };
 351
 352 static const struct snd_soc_component_driver dmaengine_pcm_component_process = {
 353         .name           = SND_DMAENGINE_PCM_DRV_NAME,
 354         .probe_order    = SND_SOC_COMP_ORDER_LATE,
 355         .open           = dmaengine_pcm_open,
 356         .close          = dmaengine_pcm_close,
 357         .hw_params      = dmaengine_pcm_hw_params,
 358         .trigger        = dmaengine_pcm_trigger,
 359         .pointer        = dmaengine_pcm_pointer,
 360         .copy_user      = dmaengine_copy_user,
 361         .pcm_construct  = dmaengine_pcm_new,
 362 };
 363
 364 static const char * const dmaengine_pcm_dma_channel_names[] = {
 365         [SNDRV_PCM_STREAM_PLAYBACK] = "tx",
 366         [SNDRV_PCM_STREAM_CAPTURE] = "rx",
 367 };
 368
 369 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
 370         struct device *dev, const struct snd_dmaengine_pcm_config *config)
 371 {
 372         unsigned int i;
 373         const char *name;
 374         struct dma_chan *chan;
 375
 376         if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node &&
 377             !(config && config->dma_dev && config->dma_dev->of_node)))
 378                 return 0;
 379
 380         if (config && config->dma_dev) {
 381                 /*
 382                  * If this warning is seen, it probably means that your Linux
 383                  * device structure does not match your HW device structure.
 384                  * It would be best to refactor the Linux device structure to
 385                  * correctly match the HW structure.
 386                  */
 387                 dev_warn(dev, "DMA channels sourced from device %s",
 388                          dev_name(config->dma_dev));
 389                 dev = config->dma_dev;
 390         }
 391
 392         for_each_pcm_streams(i) {
 393                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 394                         name = "rx-tx";
 395                 else
 396                         name = dmaengine_pcm_dma_channel_names[i];
 397                 if (config && config->chan_names[i])
 398                         name = config->chan_names[i];
 399                 chan = dma_request_chan(dev, name);
 400                 if (IS_ERR(chan)) {
 401                         if (PTR_ERR(chan) == -EPROBE_DEFER)
 402                                 return -EPROBE_DEFER;
 403                         pcm->chan[i] = NULL;
 404                 } else {
 405                         pcm->chan[i] = chan;
 406                 }
 407                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 408                         break;
 409         }
 410
 411         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 412                 pcm->chan[1] = pcm->chan[0];
 413
 414         return 0;
 415 }
 416
 417 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm)
 418 {
 419         unsigned int i;
 420
 421         for_each_pcm_streams(i) {
 422                 if (!pcm->chan[i])
 423                         continue;
 424                 dma_release_channel(pcm->chan[i]);
 425                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 426                         break;
 427         }
 428 }
 429
 430 /**
 431  * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
 432  * @dev: The parent device for the PCM device
 433  * @config: Platform specific PCM configuration
 434  * @flags: Platform specific quirks
 435  */
 436 int snd_dmaengine_pcm_register(struct device *dev,
 437         const struct snd_dmaengine_pcm_config *config, unsigned int flags)
 438 {
 439         struct dmaengine_pcm *pcm;
 440         int ret;
 441
 442         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 443         if (!pcm)
 444                 return -ENOMEM;
 445
 446 #ifdef CONFIG_DEBUG_FS
 447         pcm->component.debugfs_prefix = "dma";
 448 #endif
 449         pcm->config = config;
 450         pcm->flags = flags;
 451
 452         ret = dmaengine_pcm_request_chan_of(pcm, dev, config);
 453         if (ret)
 454                 goto err_free_dma;
 455
 456         if (config && config->process)
 457                 ret = snd_soc_add_component(dev, &pcm->component,
 458                                             &dmaengine_pcm_component_process,
 459                                             NULL, 0);
 460         else
 461                 ret = snd_soc_add_component(dev, &pcm->component,
 462                                             &dmaengine_pcm_component, NULL, 0);
 463         if (ret)
 464                 goto err_free_dma;
 465
 466         return 0;
 467
 468 err_free_dma:
 469         dmaengine_pcm_release_chan(pcm);
 470         kfree(pcm);
 471         return ret;
 472 }
 473 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
 474
 475 /**
 476  * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
 477  * @dev: Parent device the PCM was register with
 478  *
 479  * Removes a dmaengine based PCM device previously registered with
 480  * snd_dmaengine_pcm_register.
 481  */
 482 void snd_dmaengine_pcm_unregister(struct device *dev)
 483 {
 484         struct snd_soc_component *component;
 485         struct dmaengine_pcm *pcm;
 486
 487         component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME);
 488         if (!component)
 489                 return;
 490
 491         pcm = soc_component_to_pcm(component);
 492
 493         snd_soc_unregister_component(dev);
 494         dmaengine_pcm_release_chan(pcm);
 495         kfree(pcm);
 496 }
 497 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
 498
 499 MODULE_LICENSE("GPL");