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  * Return: zero if successful, or a negative error code
  53  */
  54 int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
  55         const struct snd_pcm_hw_params *params,
  56         struct dma_slave_config *slave_config)
  57 {
  58         enum dma_slave_buswidth buswidth;
  59         int bits;
  60
  61         bits = params_physical_width(params);
  62         if (bits < 8 || bits > 64)
  63                 return -EINVAL;
  64         else if (bits == 8)
  65                 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
  66         else if (bits == 16)
  67                 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
  68         else if (bits == 24)
  69                 buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES;
  70         else if (bits <= 32)
  71                 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
  72         else
  73                 buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;
  74
  75         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  76                 slave_config->direction = DMA_MEM_TO_DEV;
  77                 slave_config->dst_addr_width = buswidth;
  78         } else {
  79                 slave_config->direction = DMA_DEV_TO_MEM;
  80                 slave_config->src_addr_width = buswidth;
  81         }
  82
  83         slave_config->device_fc = false;
  84
  85         return 0;
  86 }
  87 EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
  88
  89 /**
  90  * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
  91  *  using DAI DMA data.
  92  * @substream: PCM substream
  93  * @dma_data: DAI DMA data
  94  * @slave_config: DMA slave configuration
  95  *
  96  * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width
  97  * fields of the DMA slave config from the same fields of the DAI DMA
  98  * data struct. The src and dst fields will be initialized depending on the
  99  * direction of the substream. If the substream is a playback stream the dst
 100  * fields will be initialized, if it is a capture stream the src fields will be
 101  * initialized. The {dst,src}_addr_width field will only be initialized if the
 102  * SND_DMAENGINE_PCM_DAI_FLAG_PACK flag is set or if the addr_width field of
 103  * the DAI DMA data struct is not equal to DMA_SLAVE_BUSWIDTH_UNDEFINED. If
 104  * both conditions are met the latter takes priority.
 105  */
 106 void snd_dmaengine_pcm_set_config_from_dai_data(
 107         const struct snd_pcm_substream *substream,
 108         const struct snd_dmaengine_dai_dma_data *dma_data,
 109         struct dma_slave_config *slave_config)
 110 {
 111         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 112                 slave_config->dst_addr = dma_data->addr;
 113                 slave_config->dst_maxburst = dma_data->maxburst;
 114                 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
 115                         slave_config->dst_addr_width =
 116                                 DMA_SLAVE_BUSWIDTH_UNDEFINED;
 117                 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
 118                         slave_config->dst_addr_width = dma_data->addr_width;
 119         } else {
 120                 slave_config->src_addr = dma_data->addr;
 121                 slave_config->src_maxburst = dma_data->maxburst;
 122                 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
 123                         slave_config->src_addr_width =
 124                                 DMA_SLAVE_BUSWIDTH_UNDEFINED;
 125                 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
 126                         slave_config->src_addr_width = dma_data->addr_width;
 127         }
 128
 129         slave_config->peripheral_config = dma_data->peripheral_config;
 130         slave_config->peripheral_size = dma_data->peripheral_size;
 131 }
 132 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
 133
 134 static void dmaengine_pcm_dma_complete(void *arg)
 135 {
 136         unsigned int new_pos;
 137         struct snd_pcm_substream *substream = arg;
 138         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 139
 140         new_pos = prtd->pos + snd_pcm_lib_period_bytes(substream);
 141         if (new_pos >= snd_pcm_lib_buffer_bytes(substream))
 142                 new_pos = 0;
 143         prtd->pos = new_pos;
 144
 145         snd_pcm_period_elapsed(substream);
 146 }
 147
 148 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
 149 {
 150         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 151         struct dma_chan *chan = prtd->dma_chan;
 152         struct dma_async_tx_descriptor *desc;
 153         enum dma_transfer_direction direction;
 154         unsigned long flags = DMA_CTRL_ACK;
 155
 156         direction = snd_pcm_substream_to_dma_direction(substream);
 157
 158         if (!substream->runtime->no_period_wakeup)
 159                 flags |= DMA_PREP_INTERRUPT;
 160
 161         prtd->pos = 0;
 162         desc = dmaengine_prep_dma_cyclic(chan,
 163                 substream->runtime->dma_addr,
 164                 snd_pcm_lib_buffer_bytes(substream),
 165                 snd_pcm_lib_period_bytes(substream), direction, flags);
 166
 167         if (!desc)
 168                 return -ENOMEM;
 169
 170         desc->callback = dmaengine_pcm_dma_complete;
 171         desc->callback_param = substream;
 172         prtd->cookie = dmaengine_submit(desc);
 173
 174         return 0;
 175 }
 176
 177 /**
 178  * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
 179  * @substream: PCM substream
 180  * @cmd: Trigger command
 181  *
 182  * This function can be used as the PCM trigger callback for dmaengine based PCM
 183  * driver implementations.
 184  *
 185  * Return: 0 on success, a negative error code otherwise
 186  */
 187 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 188 {
 189         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 190         struct snd_pcm_runtime *runtime = substream->runtime;
 191         int ret;
 192
 193         switch (cmd) {
 194         case SNDRV_PCM_TRIGGER_START:
 195                 ret = dmaengine_pcm_prepare_and_submit(substream);
 196                 if (ret)
 197                         return ret;
 198                 dma_async_issue_pending(prtd->dma_chan);
 199                 break;
 200         case SNDRV_PCM_TRIGGER_RESUME:
 201         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 202                 dmaengine_resume(prtd->dma_chan);
 203                 break;
 204         case SNDRV_PCM_TRIGGER_SUSPEND:
 205                 if (runtime->info & SNDRV_PCM_INFO_PAUSE)
 206                         dmaengine_pause(prtd->dma_chan);
 207                 else
 208                         dmaengine_terminate_async(prtd->dma_chan);
 209                 break;
 210         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 211                 dmaengine_pause(prtd->dma_chan);
 212                 break;
 213         case SNDRV_PCM_TRIGGER_STOP:
 214                 dmaengine_terminate_async(prtd->dma_chan);
 215                 break;
 216         default:
 217                 return -EINVAL;
 218         }
 219
 220         return 0;
 221 }
 222 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
 223
 224 /**
 225  * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
 226  * @substream: PCM substream
 227  *
 228  * This function is deprecated and should not be used by new drivers, as its
 229  * results may be unreliable.
 230  *
 231  * Return: PCM position in frames
 232  */
 233 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
 234 {
 235         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 236         return bytes_to_frames(substream->runtime, prtd->pos);
 237 }
 238 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
 239
 240 /**
 241  * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
 242  * @substream: PCM substream
 243  *
 244  * This function can be used as the PCM pointer callback for dmaengine based PCM
 245  * driver implementations.
 246  *
 247  * Return: PCM position in frames
 248  */
 249 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
 250 {
 251         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 252         struct snd_pcm_runtime *runtime = substream->runtime;
 253         struct dma_tx_state state;
 254         enum dma_status status;
 255         unsigned int buf_size;
 256         unsigned int pos = 0;
 257
 258         status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
 259         if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
 260                 buf_size = snd_pcm_lib_buffer_bytes(substream);
 261                 if (state.residue > 0 && state.residue <= buf_size)
 262                         pos = buf_size - state.residue;
 263
 264                 runtime->delay = bytes_to_frames(runtime,
 265                                                  state.in_flight_bytes);
 266         }
 267
 268         return bytes_to_frames(runtime, pos);
 269 }
 270 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
 271
 272 /**
 273  * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
 274  * @filter_fn: Filter function used to request the DMA channel
 275  * @filter_data: Data passed to the DMA filter function
 276  *
 277  * This function request a DMA channel for usage with dmaengine PCM.
 278  *
 279  * Return: NULL or the requested DMA channel
 280  */
 281 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
 282         void *filter_data)
 283 {
 284         dma_cap_mask_t mask;
 285
 286         dma_cap_zero(mask);
 287         dma_cap_set(DMA_SLAVE, mask);
 288         dma_cap_set(DMA_CYCLIC, mask);
 289
 290         return dma_request_channel(mask, filter_fn, filter_data);
 291 }
 292 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
 293
 294 /**
 295  * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
 296  * @substream: PCM substream
 297  * @chan: DMA channel to use for data transfers
 298  *
 299  * The function should usually be called from the pcm open callback. Note that
 300  * this function will use private_data field of the substream's runtime. So it
 301  * is not available to your pcm driver implementation.
 302  *
 303  * Return: 0 on success, a negative error code otherwise
 304  */
 305 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
 306         struct dma_chan *chan)
 307 {
 308         struct dmaengine_pcm_runtime_data *prtd;
 309         int ret;
 310
 311         if (!chan)
 312                 return -ENXIO;
 313
 314         ret = snd_pcm_hw_constraint_integer(substream->runtime,
 315                                             SNDRV_PCM_HW_PARAM_PERIODS);
 316         if (ret < 0)
 317                 return ret;
 318
 319         prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 320         if (!prtd)
 321                 return -ENOMEM;
 322
 323         prtd->dma_chan = chan;
 324
 325         substream->runtime->private_data = prtd;
 326
 327         return 0;
 328 }
 329 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
 330
 331 /**
 332  * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
 333  * @substream: PCM substream
 334  * @filter_fn: Filter function used to request the DMA channel
 335  * @filter_data: Data passed to the DMA filter function
 336  *
 337  * This function will request a DMA channel using the passed filter function and
 338  * data. The function should usually be called from the pcm open callback. Note
 339  * that this function will use private_data field of the substream's runtime. So
 340  * it is not available to your pcm driver implementation.
 341  *
 342  * Return: 0 on success, a negative error code otherwise
 343  */
 344 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
 345         dma_filter_fn filter_fn, void *filter_data)
 346 {
 347         return snd_dmaengine_pcm_open(substream,
 348                     snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
 349 }
 350 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
 351
 352 /**
 353  * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
 354  * @substream: PCM substream
 355  *
 356  * Return: 0 on success, a negative error code otherwise
 357  */
 358 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
 359 {
 360         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 361
 362         dmaengine_synchronize(prtd->dma_chan);
 363         kfree(prtd);
 364
 365         return 0;
 366 }
 367 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
 368
 369 /**
 370  * snd_dmaengine_pcm_close_release_chan - Close a dmaengine based PCM
 371  *                                        substream and release channel
 372  * @substream: PCM substream
 373  *
 374  * Releases the DMA channel associated with the PCM substream.
 375  *
 376  * Return: zero if successful, or a negative error code
 377  */
 378 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
 379 {
 380         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 381
 382         dmaengine_synchronize(prtd->dma_chan);
 383         dma_release_channel(prtd->dma_chan);
 384         kfree(prtd);
 385
 386         return 0;
 387 }
 388 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
 389
 390 /**
 391  * snd_dmaengine_pcm_refine_runtime_hwparams - Refine runtime hw params
 392  * @substream: PCM substream
 393  * @dma_data: DAI DMA data
 394  * @hw: PCM hw params
 395  * @chan: DMA channel to use for data transfers
 396  *
 397  * This function will query DMA capability, then refine the pcm hardware
 398  * parameters.
 399  *
 400  * Return: 0 on success, a negative error code otherwise
 401  */
 402 int snd_dmaengine_pcm_refine_runtime_hwparams(
 403         struct snd_pcm_substream *substream,
 404         struct snd_dmaengine_dai_dma_data *dma_data,
 405         struct snd_pcm_hardware *hw,
 406         struct dma_chan *chan)
 407 {
 408         struct dma_slave_caps dma_caps;
 409         u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
 410                           BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
 411                           BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
 412         snd_pcm_format_t i;
 413         int ret = 0;
 414
 415         if (!hw || !chan || !dma_data)
 416                 return -EINVAL;
 417
 418         ret = dma_get_slave_caps(chan, &dma_caps);
 419         if (ret == 0) {
 420                 if (dma_caps.cmd_pause && dma_caps.cmd_resume)
 421                         hw->info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME;
 422                 if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT)
 423                         hw->info |= SNDRV_PCM_INFO_BATCH;
 424
 425                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 426                         addr_widths = dma_caps.dst_addr_widths;
 427                 else
 428                         addr_widths = dma_caps.src_addr_widths;
 429         }
 430
 431         /*
 432          * If SND_DMAENGINE_PCM_DAI_FLAG_PACK is set keep
 433          * hw.formats set to 0, meaning no restrictions are in place.
 434          * In this case it's the responsibility of the DAI driver to
 435          * provide the supported format information.
 436          */
 437         if (!(dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK))
 438                 /*
 439                  * Prepare formats mask for valid/allowed sample types. If the
 440                  * dma does not have support for the given physical word size,
 441                  * it needs to be masked out so user space can not use the
 442                  * format which produces corrupted audio.
 443                  * In case the dma driver does not implement the slave_caps the
 444                  * default assumption is that it supports 1, 2 and 4 bytes
 445                  * widths.
 446                  */
 447                 pcm_for_each_format(i) {
 448                         int bits = snd_pcm_format_physical_width(i);
 449
 450                         /*
 451                          * Enable only samples with DMA supported physical
 452                          * widths
 453                          */
 454                         switch (bits) {
 455                         case 8:
 456                         case 16:
 457                         case 24:
 458                         case 32:
 459                         case 64:
 460                                 if (addr_widths & (1 << (bits / 8)))
 461                                         hw->formats |= pcm_format_to_bits(i);
 462                                 break;
 463                         default:
 464                                 /* Unsupported types */
 465                                 break;
 466                         }
 467                 }
 468
 469         return ret;
 470 }
 471 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_refine_runtime_hwparams);
 472
 473 MODULE_LICENSE("GPL");