sound/core/pcm_dmaengine.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Copyright (C) 2012, Analog Devices Inc.
   4  *      Author: Lars-Peter Clausen <lars@metafoo.de>
   5  *
   6  *  Based on:
   7  *      imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
   8  *      mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc.
   9  *      ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
  10  *                    Copyright (C) 2006 Applied Data Systems
  11  */
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/dmaengine.h>
  15 #include <linux/slab.h>
  16 #include <sound/pcm.h>
  17 #include <sound/pcm_params.h>
  18 #include <sound/soc.h>
  19
  20 #include <sound/dmaengine_pcm.h>
  21
  22 struct dmaengine_pcm_runtime_data {
  23         struct dma_chan *dma_chan;
  24         dma_cookie_t cookie;
  25
  26         unsigned int pos;
  27 };
  28
  29 static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
  30         const struct snd_pcm_substream *substream)
  31 {
  32         return substream->runtime->private_data;
  33 }
  34
  35 struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
  36 {
  37         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  38
  39         return prtd->dma_chan;
  40 }
  41 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);
  42
  43 /**
  44  * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
  45  * @substream: PCM substream
  46  * @params: hw_params
  47  * @slave_config: DMA slave config
  48  *
  49  * This function can be used to initialize a dma_slave_config from a substream
  50  * and hw_params in a dmaengine based PCM driver implementation.
  51  */
  52 int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
  53         const struct snd_pcm_hw_params *params,
  54         struct dma_slave_config *slave_config)
  55 {
  56         enum dma_slave_buswidth buswidth;
  57         int bits;
  58
  59         bits = params_physical_width(params);
  60         if (bits < 8 || bits > 64)
  61                 return -EINVAL;
  62         else if (bits == 8)
  63                 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
  64         else if (bits == 16)
  65                 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
  66         else if (bits == 24)
  67                 buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES;
  68         else if (bits <= 32)
  69                 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
  70         else
  71                 buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;
  72
  73         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  74                 slave_config->direction = DMA_MEM_TO_DEV;
  75                 slave_config->dst_addr_width = buswidth;
  76         } else {
  77                 slave_config->direction = DMA_DEV_TO_MEM;
  78                 slave_config->src_addr_width = buswidth;
  79         }
  80
  81         slave_config->device_fc = false;
  82
  83         return 0;
  84 }
  85 EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
  86
  87 /**
  88  * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
  89  *  using DAI DMA data.
  90  * @substream: PCM substream
  91  * @dma_data: DAI DMA data
  92  * @slave_config: DMA slave configuration
  93  *
  94  * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and
  95  * slave_id fields of the DMA slave config from the same fields of the DAI DMA
  96  * data struct. The src and dst fields will be initialized depending on the
  97  * direction of the substream. If the substream is a playback stream the dst
  98  * fields will be initialized, if it is a capture stream the src fields will be
  99  * initialized. The {dst,src}_addr_width field will only be initialized if the
 100  * SND_DMAENGINE_PCM_DAI_FLAG_PACK flag is set or if the addr_width field of
 101  * the DAI DMA data struct is not equal to DMA_SLAVE_BUSWIDTH_UNDEFINED. If
 102  * both conditions are met the latter takes priority.
 103  */
 104 void snd_dmaengine_pcm_set_config_from_dai_data(
 105         const struct snd_pcm_substream *substream,
 106         const struct snd_dmaengine_dai_dma_data *dma_data,
 107         struct dma_slave_config *slave_config)
 108 {
 109         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 110                 slave_config->dst_addr = dma_data->addr;
 111                 slave_config->dst_maxburst = dma_data->maxburst;
 112                 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
 113                         slave_config->dst_addr_width =
 114                                 DMA_SLAVE_BUSWIDTH_UNDEFINED;
 115                 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
 116                         slave_config->dst_addr_width = dma_data->addr_width;
 117         } else {
 118                 slave_config->src_addr = dma_data->addr;
 119                 slave_config->src_maxburst = dma_data->maxburst;
 120                 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
 121                         slave_config->src_addr_width =
 122                                 DMA_SLAVE_BUSWIDTH_UNDEFINED;
 123                 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
 124                         slave_config->src_addr_width = dma_data->addr_width;
 125         }
 126
 127         slave_config->slave_id = dma_data->slave_id;
 128         slave_config->peripheral_config = dma_data->peripheral_config;
 129         slave_config->peripheral_size = dma_data->peripheral_size;
 130 }
 131 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
 132
 133 static void dmaengine_pcm_dma_complete(void *arg)
 134 {
 135         unsigned int new_pos;
 136         struct snd_pcm_substream *substream = arg;
 137         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 138
 139         new_pos = prtd->pos + snd_pcm_lib_period_bytes(substream);
 140         if (new_pos >= snd_pcm_lib_buffer_bytes(substream))
 141                 new_pos = 0;
 142         prtd->pos = new_pos;
 143
 144         snd_pcm_period_elapsed(substream);
 145 }
 146
 147 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
 148 {
 149         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 150         struct dma_chan *chan = prtd->dma_chan;
 151         struct dma_async_tx_descriptor *desc;
 152         enum dma_transfer_direction direction;
 153         unsigned long flags = DMA_CTRL_ACK;
 154
 155         direction = snd_pcm_substream_to_dma_direction(substream);
 156
 157         if (!substream->runtime->no_period_wakeup)
 158                 flags |= DMA_PREP_INTERRUPT;
 159
 160         prtd->pos = 0;
 161         desc = dmaengine_prep_dma_cyclic(chan,
 162                 substream->runtime->dma_addr,
 163                 snd_pcm_lib_buffer_bytes(substream),
 164                 snd_pcm_lib_period_bytes(substream), direction, flags);
 165
 166         if (!desc)
 167                 return -ENOMEM;
 168
 169         desc->callback = dmaengine_pcm_dma_complete;
 170         desc->callback_param = substream;
 171         prtd->cookie = dmaengine_submit(desc);
 172
 173         return 0;
 174 }
 175
 176 /**
 177  * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
 178  * @substream: PCM substream
 179  * @cmd: Trigger command
 180  *
 181  * Returns 0 on success, a negative error code otherwise.
 182  *
 183  * This function can be used as the PCM trigger callback for dmaengine based PCM
 184  * driver implementations.
 185  */
 186 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 187 {
 188         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 189         struct snd_pcm_runtime *runtime = substream->runtime;
 190         int ret;
 191
 192         switch (cmd) {
 193         case SNDRV_PCM_TRIGGER_START:
 194                 ret = dmaengine_pcm_prepare_and_submit(substream);
 195                 if (ret)
 196                         return ret;
 197                 dma_async_issue_pending(prtd->dma_chan);
 198                 break;
 199         case SNDRV_PCM_TRIGGER_RESUME:
 200         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 201                 dmaengine_resume(prtd->dma_chan);
 202                 break;
 203         case SNDRV_PCM_TRIGGER_SUSPEND:
 204                 if (runtime->info & SNDRV_PCM_INFO_PAUSE)
 205                         dmaengine_pause(prtd->dma_chan);
 206                 else
 207                         dmaengine_terminate_async(prtd->dma_chan);
 208                 break;
 209         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 210                 dmaengine_pause(prtd->dma_chan);
 211                 break;
 212         case SNDRV_PCM_TRIGGER_STOP:
 213                 dmaengine_terminate_async(prtd->dma_chan);
 214                 break;
 215         default:
 216                 return -EINVAL;
 217         }
 218
 219         return 0;
 220 }
 221 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
 222
 223 /**
 224  * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
 225  * @substream: PCM substream
 226  *
 227  * This function is deprecated and should not be used by new drivers, as its
 228  * results may be unreliable.
 229  */
 230 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
 231 {
 232         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 233         return bytes_to_frames(substream->runtime, prtd->pos);
 234 }
 235 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
 236
 237 /**
 238  * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
 239  * @substream: PCM substream
 240  *
 241  * This function can be used as the PCM pointer callback for dmaengine based PCM
 242  * driver implementations.
 243  */
 244 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
 245 {
 246         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 247         struct snd_pcm_runtime *runtime = substream->runtime;
 248         struct dma_tx_state state;
 249         enum dma_status status;
 250         unsigned int buf_size;
 251         unsigned int pos = 0;
 252
 253         status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
 254         if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
 255                 buf_size = snd_pcm_lib_buffer_bytes(substream);
 256                 if (state.residue > 0 && state.residue <= buf_size)
 257                         pos = buf_size - state.residue;
 258
 259                 runtime->delay = bytes_to_frames(runtime,
 260                                                  state.in_flight_bytes);
 261         }
 262
 263         return bytes_to_frames(runtime, pos);
 264 }
 265 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
 266
 267 /**
 268  * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
 269  * @filter_fn: Filter function used to request the DMA channel
 270  * @filter_data: Data passed to the DMA filter function
 271  *
 272  * Returns NULL or the requested DMA channel.
 273  *
 274  * This function request a DMA channel for usage with dmaengine PCM.
 275  */
 276 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
 277         void *filter_data)
 278 {
 279         dma_cap_mask_t mask;
 280
 281         dma_cap_zero(mask);
 282         dma_cap_set(DMA_SLAVE, mask);
 283         dma_cap_set(DMA_CYCLIC, mask);
 284
 285         return dma_request_channel(mask, filter_fn, filter_data);
 286 }
 287 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
 288
 289 /**
 290  * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
 291  * @substream: PCM substream
 292  * @chan: DMA channel to use for data transfers
 293  *
 294  * Returns 0 on success, a negative error code otherwise.
 295  *
 296  * The function should usually be called from the pcm open callback. Note that
 297  * this function will use private_data field of the substream's runtime. So it
 298  * is not available to your pcm driver implementation.
 299  */
 300 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
 301         struct dma_chan *chan)
 302 {
 303         struct dmaengine_pcm_runtime_data *prtd;
 304         int ret;
 305
 306         if (!chan)
 307                 return -ENXIO;
 308
 309         ret = snd_pcm_hw_constraint_integer(substream->runtime,
 310                                             SNDRV_PCM_HW_PARAM_PERIODS);
 311         if (ret < 0)
 312                 return ret;
 313
 314         prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 315         if (!prtd)
 316                 return -ENOMEM;
 317
 318         prtd->dma_chan = chan;
 319
 320         substream->runtime->private_data = prtd;
 321
 322         return 0;
 323 }
 324 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
 325
 326 /**
 327  * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
 328  * @substream: PCM substream
 329  * @filter_fn: Filter function used to request the DMA channel
 330  * @filter_data: Data passed to the DMA filter function
 331  *
 332  * Returns 0 on success, a negative error code otherwise.
 333  *
 334  * This function will request a DMA channel using the passed filter function and
 335  * data. The function should usually be called from the pcm open callback. Note
 336  * that this function will use private_data field of the substream's runtime. So
 337  * it is not available to your pcm driver implementation.
 338  */
 339 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
 340         dma_filter_fn filter_fn, void *filter_data)
 341 {
 342         return snd_dmaengine_pcm_open(substream,
 343                     snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
 344 }
 345 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
 346
 347 /**
 348  * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
 349  * @substream: PCM substream
 350  */
 351 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
 352 {
 353         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 354
 355         dmaengine_synchronize(prtd->dma_chan);
 356         kfree(prtd);
 357
 358         return 0;
 359 }
 360 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
 361
 362 /**
 363  * snd_dmaengine_pcm_close_release_chan - Close a dmaengine based PCM
 364  *                                        substream and release channel
 365  * @substream: PCM substream
 366  *
 367  * Releases the DMA channel associated with the PCM substream.
 368  */
 369 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
 370 {
 371         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 372
 373         dmaengine_synchronize(prtd->dma_chan);
 374         dma_release_channel(prtd->dma_chan);
 375         kfree(prtd);
 376
 377         return 0;
 378 }
 379 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
 380
 381 /**
 382  * snd_dmaengine_pcm_refine_runtime_hwparams - Refine runtime hw params
 383  * @substream: PCM substream
 384  * @dma_data: DAI DMA data
 385  * @hw: PCM hw params
 386  * @chan: DMA channel to use for data transfers
 387  *
 388  * Returns 0 on success, a negative error code otherwise.
 389  *
 390  * This function will query DMA capability, then refine the pcm hardware
 391  * parameters.
 392  */
 393 int snd_dmaengine_pcm_refine_runtime_hwparams(
 394         struct snd_pcm_substream *substream,
 395         struct snd_dmaengine_dai_dma_data *dma_data,
 396         struct snd_pcm_hardware *hw,
 397         struct dma_chan *chan)
 398 {
 399         struct dma_slave_caps dma_caps;
 400         u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
 401                           BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
 402                           BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
 403         snd_pcm_format_t i;
 404         int ret = 0;
 405
 406         if (!hw || !chan || !dma_data)
 407                 return -EINVAL;
 408
 409         ret = dma_get_slave_caps(chan, &dma_caps);
 410         if (ret == 0) {
 411                 if (dma_caps.cmd_pause && dma_caps.cmd_resume)
 412                         hw->info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME;
 413                 if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT)
 414                         hw->info |= SNDRV_PCM_INFO_BATCH;
 415
 416                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 417                         addr_widths = dma_caps.dst_addr_widths;
 418                 else
 419                         addr_widths = dma_caps.src_addr_widths;
 420         }
 421
 422         /*
 423          * If SND_DMAENGINE_PCM_DAI_FLAG_PACK is set keep
 424          * hw.formats set to 0, meaning no restrictions are in place.
 425          * In this case it's the responsibility of the DAI driver to
 426          * provide the supported format information.
 427          */
 428         if (!(dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK))
 429                 /*
 430                  * Prepare formats mask for valid/allowed sample types. If the
 431                  * dma does not have support for the given physical word size,
 432                  * it needs to be masked out so user space can not use the
 433                  * format which produces corrupted audio.
 434                  * In case the dma driver does not implement the slave_caps the
 435                  * default assumption is that it supports 1, 2 and 4 bytes
 436                  * widths.
 437                  */
 438                 pcm_for_each_format(i) {
 439                         int bits = snd_pcm_format_physical_width(i);
 440
 441                         /*
 442                          * Enable only samples with DMA supported physical
 443                          * widths
 444                          */
 445                         switch (bits) {
 446                         case 8:
 447                         case 16:
 448                         case 24:
 449                         case 32:
 450                         case 64:
 451                                 if (addr_widths & (1 << (bits / 8)))
 452                                         hw->formats |= pcm_format_to_bits(i);
 453                                 break;
 454                         default:
 455                                 /* Unsupported types */
 456                                 break;
 457                         }
 458                 }
 459
 460         return ret;
 461 }
 462 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_refine_runtime_hwparams);
 463
 464 MODULE_LICENSE("GPL");