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