sound/soc/soc-generic-dmaengine-pcm.c

   1 /*
   2  *  Copyright (C) 2013, Analog Devices Inc.
   3  *      Author: Lars-Peter Clausen <lars@metafoo.de>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify it
   6  *  under  the terms of the GNU General  Public License as published by the
   7  *  Free Software Foundation;  either version 2 of the License, or (at your
   8  *  option) any later version.
   9  *
  10  *  You should have received a copy of the GNU General Public License along
  11  *  with this program; if not, write to the Free Software Foundation, Inc.,
  12  *  675 Mass Ave, Cambridge, MA 02139, USA.
  13  *
  14  */
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/dmaengine.h>
  18 #include <linux/slab.h>
  19 #include <sound/pcm.h>
  20 #include <sound/pcm_params.h>
  21 #include <sound/soc.h>
  22 #include <linux/dma-mapping.h>
  23 #include <linux/of.h>
  24
  25 #include <sound/dmaengine_pcm.h>
  26
  27 /*
  28  * The platforms dmaengine driver does not support reporting the amount of
  29  * bytes that are still left to transfer.
  30  */
  31 #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31)
  32
  33 struct dmaengine_pcm {
  34         struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1];
  35         const struct snd_dmaengine_pcm_config *config;
  36         struct snd_soc_platform platform;
  37         unsigned int flags;
  38 };
  39
  40 static struct dmaengine_pcm *soc_platform_to_pcm(struct snd_soc_platform *p)
  41 {
  42         return container_of(p, struct dmaengine_pcm, platform);
  43 }
  44
  45 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm,
  46         struct snd_pcm_substream *substream)
  47 {
  48         if (!pcm->chan[substream->stream])
  49                 return NULL;
  50
  51         return pcm->chan[substream->stream]->device->dev;
  52 }
  53
  54 /**
  55  * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback
  56  * @substream: PCM substream
  57  * @params: hw_params
  58  * @slave_config: DMA slave config to prepare
  59  *
  60  * This function can be used as a generic prepare_slave_config callback for
  61  * platforms which make use of the snd_dmaengine_dai_dma_data struct for their
  62  * DAI DMA data. Internally the function will first call
  63  * snd_hwparams_to_dma_slave_config to fill in the slave config based on the
  64  * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the
  65  * remaining fields based on the DAI DMA data.
  66  */
  67 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
  68         struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
  69 {
  70         struct snd_soc_pcm_runtime *rtd = substream->private_data;
  71         struct snd_dmaengine_dai_dma_data *dma_data;
  72         int ret;
  73
  74         dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
  75
  76         ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
  77         if (ret)
  78                 return ret;
  79
  80         snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data,
  81                 slave_config);
  82
  83         return 0;
  84 }
  85 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);
  86
  87 static int dmaengine_pcm_hw_params(struct snd_pcm_substream *substream,
  88         struct snd_pcm_hw_params *params)
  89 {
  90         struct snd_soc_pcm_runtime *rtd = substream->private_data;
  91         struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
  92         struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
  93         int (*prepare_slave_config)(struct snd_pcm_substream *substream,
  94                         struct snd_pcm_hw_params *params,
  95                         struct dma_slave_config *slave_config);
  96         struct dma_slave_config slave_config;
  97         int ret;
  98
  99         memset(&slave_config, 0, sizeof(slave_config));
 100
 101         if (!pcm->config)
 102                 prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config;
 103         else
 104                 prepare_slave_config = pcm->config->prepare_slave_config;
 105
 106         if (prepare_slave_config) {
 107                 ret = prepare_slave_config(substream, params, &slave_config);
 108                 if (ret)
 109                         return ret;
 110
 111                 ret = dmaengine_slave_config(chan, &slave_config);
 112                 if (ret)
 113                         return ret;
 114         }
 115
 116         return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
 117 }
 118
 119 static int dmaengine_pcm_set_runtime_hwparams(struct snd_pcm_substream *substream)
 120 {
 121         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 122         struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
 123         struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
 124         struct dma_chan *chan = pcm->chan[substream->stream];
 125         struct snd_dmaengine_dai_dma_data *dma_data;
 126         struct dma_slave_caps dma_caps;
 127         struct snd_pcm_hardware hw;
 128         u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
 129                           BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
 130                           BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
 131         int i, ret;
 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(rtd->cpu_dai, 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         ret = dma_get_slave_caps(chan, &dma_caps);
 153         if (ret == 0) {
 154                 if (dma_caps.cmd_pause)
 155                         hw.info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME;
 156                 if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT)
 157                         hw.info |= SNDRV_PCM_INFO_BATCH;
 158
 159                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 160                         addr_widths = dma_caps.dst_addr_widths;
 161                 else
 162                         addr_widths = dma_caps.src_addr_widths;
 163         }
 164
 165         /*
 166          * If SND_DMAENGINE_PCM_DAI_FLAG_PACK is set keep
 167          * hw.formats set to 0, meaning no restrictions are in place.
 168          * In this case it's the responsibility of the DAI driver to
 169          * provide the supported format information.
 170          */
 171         if (!(dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK))
 172                 /*
 173                  * Prepare formats mask for valid/allowed sample types. If the
 174                  * dma does not have support for the given physical word size,
 175                  * it needs to be masked out so user space can not use the
 176                  * format which produces corrupted audio.
 177                  * In case the dma driver does not implement the slave_caps the
 178                  * default assumption is that it supports 1, 2 and 4 bytes
 179                  * widths.
 180                  */
 181                 for (i = 0; i <= SNDRV_PCM_FORMAT_LAST; i++) {
 182                         int bits = snd_pcm_format_physical_width(i);
 183
 184                         /*
 185                          * Enable only samples with DMA supported physical
 186                          * widths
 187                          */
 188                         switch (bits) {
 189                         case 8:
 190                         case 16:
 191                         case 24:
 192                         case 32:
 193                         case 64:
 194                                 if (addr_widths & (1 << (bits / 8)))
 195                                         hw.formats |= (1LL << i);
 196                                 break;
 197                         default:
 198                                 /* Unsupported types */
 199                                 break;
 200                         }
 201                 }
 202
 203         return snd_soc_set_runtime_hwparams(substream, &hw);
 204 }
 205
 206 static int dmaengine_pcm_open(struct snd_pcm_substream *substream)
 207 {
 208         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 209         struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
 210         struct dma_chan *chan = pcm->chan[substream->stream];
 211         int ret;
 212
 213         ret = dmaengine_pcm_set_runtime_hwparams(substream);
 214         if (ret)
 215                 return ret;
 216
 217         return snd_dmaengine_pcm_open(substream, chan);
 218 }
 219
 220 static struct dma_chan *dmaengine_pcm_compat_request_channel(
 221         struct snd_soc_pcm_runtime *rtd,
 222         struct snd_pcm_substream *substream)
 223 {
 224         struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
 225         struct snd_dmaengine_dai_dma_data *dma_data;
 226         dma_filter_fn fn = NULL;
 227
 228         dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 229
 230         if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
 231                 return pcm->chan[0];
 232
 233         if (pcm->config && pcm->config->compat_request_channel)
 234                 return pcm->config->compat_request_channel(rtd, substream);
 235
 236         if (pcm->config)
 237                 fn = pcm->config->compat_filter_fn;
 238
 239         return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data);
 240 }
 241
 242 static bool dmaengine_pcm_can_report_residue(struct device *dev,
 243         struct dma_chan *chan)
 244 {
 245         struct dma_slave_caps dma_caps;
 246         int ret;
 247
 248         ret = dma_get_slave_caps(chan, &dma_caps);
 249         if (ret != 0) {
 250                 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n",
 251                          ret);
 252                 return false;
 253         }
 254
 255         if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR)
 256                 return false;
 257
 258         return true;
 259 }
 260
 261 static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
 262 {
 263         struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
 264         const struct snd_dmaengine_pcm_config *config = pcm->config;
 265         struct device *dev = rtd->platform->dev;
 266         struct snd_pcm_substream *substream;
 267         size_t prealloc_buffer_size;
 268         size_t max_buffer_size;
 269         unsigned int i;
 270         int ret;
 271
 272         if (config && config->prealloc_buffer_size) {
 273                 prealloc_buffer_size = config->prealloc_buffer_size;
 274                 max_buffer_size = config->pcm_hardware->buffer_bytes_max;
 275         } else {
 276                 prealloc_buffer_size = 512 * 1024;
 277                 max_buffer_size = SIZE_MAX;
 278         }
 279
 280         for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
 281                 substream = rtd->pcm->streams[i].substream;
 282                 if (!substream)
 283                         continue;
 284
 285                 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
 286                         pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd,
 287                                 substream);
 288                 }
 289
 290                 if (!pcm->chan[i]) {
 291                         dev_err(rtd->platform->dev,
 292                                 "Missing dma channel for stream: %d\n", i);
 293                         return -EINVAL;
 294                 }
 295
 296                 ret = snd_pcm_lib_preallocate_pages(substream,
 297                                 SNDRV_DMA_TYPE_DEV_IRAM,
 298                                 dmaengine_dma_dev(pcm, substream),
 299                                 prealloc_buffer_size,
 300                                 max_buffer_size);
 301                 if (ret)
 302                         return ret;
 303
 304                 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
 305                         pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
 306         }
 307
 308         return 0;
 309 }
 310
 311 static snd_pcm_uframes_t dmaengine_pcm_pointer(
 312         struct snd_pcm_substream *substream)
 313 {
 314         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 315         struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
 316
 317         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
 318                 return snd_dmaengine_pcm_pointer_no_residue(substream);
 319         else
 320                 return snd_dmaengine_pcm_pointer(substream);
 321 }
 322
 323 static const struct snd_pcm_ops dmaengine_pcm_ops = {
 324         .open           = dmaengine_pcm_open,
 325         .close          = snd_dmaengine_pcm_close,
 326         .ioctl          = snd_pcm_lib_ioctl,
 327         .hw_params      = dmaengine_pcm_hw_params,
 328         .hw_free        = snd_pcm_lib_free_pages,
 329         .trigger        = snd_dmaengine_pcm_trigger,
 330         .pointer        = dmaengine_pcm_pointer,
 331 };
 332
 333 static const struct snd_soc_platform_driver dmaengine_pcm_platform = {
 334         .component_driver = {
 335                 .probe_order = SND_SOC_COMP_ORDER_LATE,
 336         },
 337         .ops            = &dmaengine_pcm_ops,
 338         .pcm_new        = dmaengine_pcm_new,
 339 };
 340
 341 static const char * const dmaengine_pcm_dma_channel_names[] = {
 342         [SNDRV_PCM_STREAM_PLAYBACK] = "tx",
 343         [SNDRV_PCM_STREAM_CAPTURE] = "rx",
 344 };
 345
 346 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
 347         struct device *dev, const struct snd_dmaengine_pcm_config *config)
 348 {
 349         unsigned int i;
 350         const char *name;
 351         struct dma_chan *chan;
 352
 353         if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || !dev->of_node)
 354                 return 0;
 355
 356         if (config && config->dma_dev) {
 357                 /*
 358                  * If this warning is seen, it probably means that your Linux
 359                  * device structure does not match your HW device structure.
 360                  * It would be best to refactor the Linux device structure to
 361                  * correctly match the HW structure.
 362                  */
 363                 dev_warn(dev, "DMA channels sourced from device %s",
 364                          dev_name(config->dma_dev));
 365                 dev = config->dma_dev;
 366         }
 367
 368         for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
 369              i++) {
 370                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 371                         name = "rx-tx";
 372                 else
 373                         name = dmaengine_pcm_dma_channel_names[i];
 374                 if (config && config->chan_names[i])
 375                         name = config->chan_names[i];
 376                 chan = dma_request_slave_channel_reason(dev, name);
 377                 if (IS_ERR(chan)) {
 378                         if (PTR_ERR(chan) == -EPROBE_DEFER)
 379                                 return -EPROBE_DEFER;
 380                         pcm->chan[i] = NULL;
 381                 } else {
 382                         pcm->chan[i] = chan;
 383                 }
 384                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 385                         break;
 386         }
 387
 388         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 389                 pcm->chan[1] = pcm->chan[0];
 390
 391         return 0;
 392 }
 393
 394 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm)
 395 {
 396         unsigned int i;
 397
 398         for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
 399              i++) {
 400                 if (!pcm->chan[i])
 401                         continue;
 402                 dma_release_channel(pcm->chan[i]);
 403                 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 404                         break;
 405         }
 406 }
 407
 408 /**
 409  * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
 410  * @dev: The parent device for the PCM device
 411  * @config: Platform specific PCM configuration
 412  * @flags: Platform specific quirks
 413  */
 414 int snd_dmaengine_pcm_register(struct device *dev,
 415         const struct snd_dmaengine_pcm_config *config, unsigned int flags)
 416 {
 417         struct dmaengine_pcm *pcm;
 418         int ret;
 419
 420         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 421         if (!pcm)
 422                 return -ENOMEM;
 423
 424         pcm->config = config;
 425         pcm->flags = flags;
 426
 427         ret = dmaengine_pcm_request_chan_of(pcm, dev, config);
 428         if (ret)
 429                 goto err_free_dma;
 430
 431         ret = snd_soc_add_platform(dev, &pcm->platform,
 432                 &dmaengine_pcm_platform);
 433         if (ret)
 434                 goto err_free_dma;
 435
 436         return 0;
 437
 438 err_free_dma:
 439         dmaengine_pcm_release_chan(pcm);
 440         kfree(pcm);
 441         return ret;
 442 }
 443 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
 444
 445 /**
 446  * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
 447  * @dev: Parent device the PCM was register with
 448  *
 449  * Removes a dmaengine based PCM device previously registered with
 450  * snd_dmaengine_pcm_register.
 451  */
 452 void snd_dmaengine_pcm_unregister(struct device *dev)
 453 {
 454         struct snd_soc_platform *platform;
 455         struct dmaengine_pcm *pcm;
 456
 457         platform = snd_soc_lookup_platform(dev);
 458         if (!platform)
 459                 return;
 460
 461         pcm = soc_platform_to_pcm(platform);
 462
 463         snd_soc_remove_platform(platform);
 464         dmaengine_pcm_release_chan(pcm);
 465         kfree(pcm);
 466 }
 467 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
 468
 469 MODULE_LICENSE("GPL");