sound/core/pcm_dmaengine.c

   1 /*
   2  *  Copyright (C) 2012, Analog Devices Inc.
   3  *      Author: Lars-Peter Clausen <lars@metafoo.de>
   4  *
   5  *  Based on:
   6  *      imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
   7  *      mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc.
   8  *      ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
   9  *                    Copyright (C) 2006 Applied Data Systems
  10  *
  11  *  This program is free software; you can redistribute it and/or modify it
  12  *  under  the terms of the GNU General  Public License as published by the
  13  *  Free Software Foundation;  either version 2 of the License, or (at your
  14  *  option) any later version.
  15  *
  16  *  You should have received a copy of the GNU General Public License along
  17  *  with this program; if not, write to the Free Software Foundation, Inc.,
  18  *  675 Mass Ave, Cambridge, MA 02139, USA.
  19  *
  20  */
  21 #include <linux/module.h>
  22 #include <linux/init.h>
  23 #include <linux/dmaengine.h>
  24 #include <linux/slab.h>
  25 #include <sound/pcm.h>
  26 #include <sound/pcm_params.h>
  27 #include <sound/soc.h>
  28
  29 #include <sound/dmaengine_pcm.h>
  30
  31 struct dmaengine_pcm_runtime_data {
  32         struct dma_chan *dma_chan;
  33         dma_cookie_t cookie;
  34
  35         unsigned int pos;
  36 };
  37
  38 static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
  39         const struct snd_pcm_substream *substream)
  40 {
  41         return substream->runtime->private_data;
  42 }
  43
  44 struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
  45 {
  46         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  47
  48         return prtd->dma_chan;
  49 }
  50 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);
  51
  52 /**
  53  * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
  54  * @substream: PCM substream
  55  * @params: hw_params
  56  * @slave_config: DMA slave config
  57  *
  58  * This function can be used to initialize a dma_slave_config from a substream
  59  * and hw_params in a dmaengine based PCM driver implementation.
  60  */
  61 int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
  62         const struct snd_pcm_hw_params *params,
  63         struct dma_slave_config *slave_config)
  64 {
  65         enum dma_slave_buswidth buswidth;
  66         int bits;
  67
  68         bits = params_physical_width(params);
  69         if (bits < 8 || bits > 64)
  70                 return -EINVAL;
  71         else if (bits == 8)
  72                 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
  73         else if (bits == 16)
  74                 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
  75         else if (bits == 24)
  76                 buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES;
  77         else if (bits <= 32)
  78                 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
  79         else
  80                 buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;
  81
  82         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  83                 slave_config->direction = DMA_MEM_TO_DEV;
  84                 slave_config->dst_addr_width = buswidth;
  85         } else {
  86                 slave_config->direction = DMA_DEV_TO_MEM;
  87                 slave_config->src_addr_width = buswidth;
  88         }
  89
  90         slave_config->device_fc = false;
  91
  92         return 0;
  93 }
  94 EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
  95
  96 /**
  97  * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
  98  *  using DAI DMA data.
  99  * @substream: PCM substream
 100  * @dma_data: DAI DMA data
 101  * @slave_config: DMA slave configuration
 102  *
 103  * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and
 104  * slave_id fields of the DMA slave config from the same fields of the DAI DMA
 105  * data struct. The src and dst fields will be initialized depending on the
 106  * direction of the substream. If the substream is a playback stream the dst
 107  * fields will be initialized, if it is a capture stream the src fields will be
 108  * initialized. The {dst,src}_addr_width field will only be initialized if the
 109  * SND_DMAENGINE_PCM_DAI_FLAG_PACK flag is set or if the addr_width field of
 110  * the DAI DMA data struct is not equal to DMA_SLAVE_BUSWIDTH_UNDEFINED. If
 111  * both conditions are met the latter takes priority.
 112  */
 113 void snd_dmaengine_pcm_set_config_from_dai_data(
 114         const struct snd_pcm_substream *substream,
 115         const struct snd_dmaengine_dai_dma_data *dma_data,
 116         struct dma_slave_config *slave_config)
 117 {
 118         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 119                 slave_config->dst_addr = dma_data->addr;
 120                 slave_config->dst_maxburst = dma_data->maxburst;
 121                 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
 122                         slave_config->dst_addr_width =
 123                                 DMA_SLAVE_BUSWIDTH_UNDEFINED;
 124                 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
 125                         slave_config->dst_addr_width = dma_data->addr_width;
 126         } else {
 127                 slave_config->src_addr = dma_data->addr;
 128                 slave_config->src_maxburst = dma_data->maxburst;
 129                 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
 130                         slave_config->src_addr_width =
 131                                 DMA_SLAVE_BUSWIDTH_UNDEFINED;
 132                 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
 133                         slave_config->src_addr_width = dma_data->addr_width;
 134         }
 135
 136         slave_config->slave_id = dma_data->slave_id;
 137 }
 138 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
 139
 140 static void dmaengine_pcm_dma_complete(void *arg)
 141 {
 142         struct snd_pcm_substream *substream = arg;
 143         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 144
 145         prtd->pos += snd_pcm_lib_period_bytes(substream);
 146         if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
 147                 prtd->pos = 0;
 148
 149         snd_pcm_period_elapsed(substream);
 150 }
 151
 152 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
 153 {
 154         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 155         struct dma_chan *chan = prtd->dma_chan;
 156         struct dma_async_tx_descriptor *desc;
 157         enum dma_transfer_direction direction;
 158         unsigned long flags = DMA_CTRL_ACK;
 159
 160         direction = snd_pcm_substream_to_dma_direction(substream);
 161
 162         if (!substream->runtime->no_period_wakeup)
 163                 flags |= DMA_PREP_INTERRUPT;
 164
 165         prtd->pos = 0;
 166         desc = dmaengine_prep_dma_cyclic(chan,
 167                 substream->runtime->dma_addr,
 168                 snd_pcm_lib_buffer_bytes(substream),
 169                 snd_pcm_lib_period_bytes(substream), direction, flags);
 170
 171         if (!desc)
 172                 return -ENOMEM;
 173
 174         desc->callback = dmaengine_pcm_dma_complete;
 175         desc->callback_param = substream;
 176         prtd->cookie = dmaengine_submit(desc);
 177
 178         return 0;
 179 }
 180
 181 /**
 182  * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
 183  * @substream: PCM substream
 184  * @cmd: Trigger command
 185  *
 186  * Returns 0 on success, a negative error code otherwise.
 187  *
 188  * This function can be used as the PCM trigger callback for dmaengine based PCM
 189  * driver implementations.
 190  */
 191 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 192 {
 193         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 194         struct snd_pcm_runtime *runtime = substream->runtime;
 195         int ret;
 196
 197         switch (cmd) {
 198         case SNDRV_PCM_TRIGGER_START:
 199                 ret = dmaengine_pcm_prepare_and_submit(substream);
 200                 if (ret)
 201                         return ret;
 202                 dma_async_issue_pending(prtd->dma_chan);
 203                 break;
 204         case SNDRV_PCM_TRIGGER_RESUME:
 205         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 206                 dmaengine_resume(prtd->dma_chan);
 207                 break;
 208         case SNDRV_PCM_TRIGGER_SUSPEND:
 209                 if (runtime->info & SNDRV_PCM_INFO_PAUSE)
 210                         dmaengine_pause(prtd->dma_chan);
 211                 else
 212                         dmaengine_terminate_async(prtd->dma_chan);
 213                 break;
 214         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 215                 dmaengine_pause(prtd->dma_chan);
 216                 break;
 217         case SNDRV_PCM_TRIGGER_STOP:
 218                 dmaengine_terminate_async(prtd->dma_chan);
 219                 break;
 220         default:
 221                 return -EINVAL;
 222         }
 223
 224         return 0;
 225 }
 226 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
 227
 228 /**
 229  * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
 230  * @substream: PCM substream
 231  *
 232  * This function is deprecated and should not be used by new drivers, as its
 233  * results may be unreliable.
 234  */
 235 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
 236 {
 237         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 238         return bytes_to_frames(substream->runtime, prtd->pos);
 239 }
 240 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
 241
 242 /**
 243  * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
 244  * @substream: PCM substream
 245  *
 246  * This function can be used as the PCM pointer callback for dmaengine based PCM
 247  * driver implementations.
 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 dma_tx_state state;
 253         enum dma_status status;
 254         unsigned int buf_size;
 255         unsigned int pos = 0;
 256
 257         status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
 258         if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
 259                 buf_size = snd_pcm_lib_buffer_bytes(substream);
 260                 if (state.residue > 0 && state.residue <= buf_size)
 261                         pos = buf_size - state.residue;
 262         }
 263
 264         return bytes_to_frames(substream->runtime, pos);
 265 }
 266 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
 267
 268 /**
 269  * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
 270  * @filter_fn: Filter function used to request the DMA channel
 271  * @filter_data: Data passed to the DMA filter function
 272  *
 273  * Returns NULL or the requested DMA channel.
 274  *
 275  * This function request a DMA channel for usage with dmaengine PCM.
 276  */
 277 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
 278         void *filter_data)
 279 {
 280         dma_cap_mask_t mask;
 281
 282         dma_cap_zero(mask);
 283         dma_cap_set(DMA_SLAVE, mask);
 284         dma_cap_set(DMA_CYCLIC, mask);
 285
 286         return dma_request_channel(mask, filter_fn, filter_data);
 287 }
 288 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
 289
 290 /**
 291  * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
 292  * @substream: PCM substream
 293  * @chan: DMA channel to use for data transfers
 294  *
 295  * Returns 0 on success, a negative error code otherwise.
 296  *
 297  * The function should usually be called from the pcm open callback. Note that
 298  * this function will use private_data field of the substream's runtime. So it
 299  * is not available to your pcm driver implementation.
 300  */
 301 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
 302         struct dma_chan *chan)
 303 {
 304         struct dmaengine_pcm_runtime_data *prtd;
 305         int ret;
 306
 307         if (!chan)
 308                 return -ENXIO;
 309
 310         ret = snd_pcm_hw_constraint_integer(substream->runtime,
 311                                             SNDRV_PCM_HW_PARAM_PERIODS);
 312         if (ret < 0)
 313                 return ret;
 314
 315         prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 316         if (!prtd)
 317                 return -ENOMEM;
 318
 319         prtd->dma_chan = chan;
 320
 321         substream->runtime->private_data = prtd;
 322
 323         return 0;
 324 }
 325 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
 326
 327 /**
 328  * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
 329  * @substream: PCM substream
 330  * @filter_fn: Filter function used to request the DMA channel
 331  * @filter_data: Data passed to the DMA filter function
 332  *
 333  * Returns 0 on success, a negative error code otherwise.
 334  *
 335  * This function will request a DMA channel using the passed filter function and
 336  * data. The function should usually be called from the pcm open callback. Note
 337  * that this function will use private_data field of the substream's runtime. So
 338  * it is not available to your pcm driver implementation.
 339  */
 340 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
 341         dma_filter_fn filter_fn, void *filter_data)
 342 {
 343         return snd_dmaengine_pcm_open(substream,
 344                     snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
 345 }
 346 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
 347
 348 /**
 349  * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
 350  * @substream: PCM substream
 351  */
 352 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
 353 {
 354         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 355
 356         dmaengine_synchronize(prtd->dma_chan);
 357         kfree(prtd);
 358
 359         return 0;
 360 }
 361 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
 362
 363 /**
 364  * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM 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 MODULE_LICENSE("GPL");