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