linux/sound/soc/soc-dmaengine-pcm.c
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   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
  31struct dmaengine_pcm_runtime_data {
  32        struct dma_chan *dma_chan;
  33        dma_cookie_t cookie;
  34
  35        unsigned int pos;
  36};
  37
  38static 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
  44struct 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}
  50EXPORT_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 */
  61int 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
  67        switch (params_format(params)) {
  68        case SNDRV_PCM_FORMAT_S8:
  69                buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
  70                break;
  71        case SNDRV_PCM_FORMAT_S16_LE:
  72                buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
  73                break;
  74        case SNDRV_PCM_FORMAT_S18_3LE:
  75        case SNDRV_PCM_FORMAT_S20_3LE:
  76        case SNDRV_PCM_FORMAT_S24_LE:
  77        case SNDRV_PCM_FORMAT_S32_LE:
  78                buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
  79                break;
  80        default:
  81                return -EINVAL;
  82        }
  83
  84        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  85                slave_config->direction = DMA_MEM_TO_DEV;
  86                slave_config->dst_addr_width = buswidth;
  87        } else {
  88                slave_config->direction = DMA_DEV_TO_MEM;
  89                slave_config->src_addr_width = buswidth;
  90        }
  91
  92        slave_config->device_fc = false;
  93
  94        return 0;
  95}
  96EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
  97
  98/**
  99 * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
 100 *  using DAI DMA data.
 101 * @substream: PCM substream
 102 * @dma_data: DAI DMA data
 103 * @slave_config: DMA slave configuration
 104 *
 105 * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and
 106 * slave_id fields of the DMA slave config from the same fields of the DAI DMA
 107 * data struct. The src and dst fields will be initialized depending on the
 108 * direction of the substream. If the substream is a playback stream the dst
 109 * fields will be initialized, if it is a capture stream the src fields will be
 110 * initialized. The {dst,src}_addr_width field will only be initialized if the
 111 * addr_width field of the DAI DMA data struct is not equal to
 112 * DMA_SLAVE_BUSWIDTH_UNDEFINED.
 113 */
 114void snd_dmaengine_pcm_set_config_from_dai_data(
 115        const struct snd_pcm_substream *substream,
 116        const struct snd_dmaengine_dai_dma_data *dma_data,
 117        struct dma_slave_config *slave_config)
 118{
 119        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 120                slave_config->dst_addr = dma_data->addr;
 121                slave_config->dst_maxburst = dma_data->maxburst;
 122                if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
 123                        slave_config->dst_addr_width = dma_data->addr_width;
 124        } else {
 125                slave_config->src_addr = dma_data->addr;
 126                slave_config->src_maxburst = dma_data->maxburst;
 127                if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
 128                        slave_config->src_addr_width = dma_data->addr_width;
 129        }
 130
 131        slave_config->slave_id = dma_data->slave_id;
 132}
 133EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
 134
 135static void dmaengine_pcm_dma_complete(void *arg)
 136{
 137        struct snd_pcm_substream *substream = arg;
 138        struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 139
 140        prtd->pos += snd_pcm_lib_period_bytes(substream);
 141        if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
 142                prtd->pos = 0;
 143
 144        snd_pcm_period_elapsed(substream);
 145}
 146
 147static 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 */
 186int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 187{
 188        struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 189        int ret;
 190
 191        switch (cmd) {
 192        case SNDRV_PCM_TRIGGER_START:
 193                ret = dmaengine_pcm_prepare_and_submit(substream);
 194                if (ret)
 195                        return ret;
 196                dma_async_issue_pending(prtd->dma_chan);
 197                break;
 198        case SNDRV_PCM_TRIGGER_RESUME:
 199        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 200                dmaengine_resume(prtd->dma_chan);
 201                break;
 202        case SNDRV_PCM_TRIGGER_SUSPEND:
 203        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 204                dmaengine_pause(prtd->dma_chan);
 205                break;
 206        case SNDRV_PCM_TRIGGER_STOP:
 207                dmaengine_terminate_all(prtd->dma_chan);
 208                break;
 209        default:
 210                return -EINVAL;
 211        }
 212
 213        return 0;
 214}
 215EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
 216
 217/**
 218 * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
 219 * @substream: PCM substream
 220 *
 221 * This function is deprecated and should not be used by new drivers, as its
 222 * results may be unreliable.
 223 */
 224snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
 225{
 226        struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 227        return bytes_to_frames(substream->runtime, prtd->pos);
 228}
 229EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
 230
 231/**
 232 * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
 233 * @substream: PCM substream
 234 *
 235 * This function can be used as the PCM pointer callback for dmaengine based PCM
 236 * driver implementations.
 237 */
 238snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
 239{
 240        struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 241        struct dma_tx_state state;
 242        enum dma_status status;
 243        unsigned int buf_size;
 244        unsigned int pos = 0;
 245
 246        status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
 247        if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
 248                buf_size = snd_pcm_lib_buffer_bytes(substream);
 249                if (state.residue > 0 && state.residue <= buf_size)
 250                        pos = buf_size - state.residue;
 251        }
 252
 253        return bytes_to_frames(substream->runtime, pos);
 254}
 255EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
 256
 257/**
 258 * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
 259 * @filter_fn: Filter function used to request the DMA channel
 260 * @filter_data: Data passed to the DMA filter function
 261 *
 262 * Returns NULL or the requested DMA channel.
 263 *
 264 * This function request a DMA channel for usage with dmaengine PCM.
 265 */
 266struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
 267        void *filter_data)
 268{
 269        dma_cap_mask_t mask;
 270
 271        dma_cap_zero(mask);
 272        dma_cap_set(DMA_SLAVE, mask);
 273        dma_cap_set(DMA_CYCLIC, mask);
 274
 275        return dma_request_channel(mask, filter_fn, filter_data);
 276}
 277EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
 278
 279/**
 280 * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
 281 * @substream: PCM substream
 282 * @chan: DMA channel to use for data transfers
 283 *
 284 * Returns 0 on success, a negative error code otherwise.
 285 *
 286 * The function should usually be called from the pcm open callback. Note that
 287 * this function will use private_data field of the substream's runtime. So it
 288 * is not availabe to your pcm driver implementation.
 289 */
 290int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
 291        struct dma_chan *chan)
 292{
 293        struct dmaengine_pcm_runtime_data *prtd;
 294        int ret;
 295
 296        if (!chan)
 297                return -ENXIO;
 298
 299        ret = snd_pcm_hw_constraint_integer(substream->runtime,
 300                                            SNDRV_PCM_HW_PARAM_PERIODS);
 301        if (ret < 0)
 302                return ret;
 303
 304        prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 305        if (!prtd)
 306                return -ENOMEM;
 307
 308        prtd->dma_chan = chan;
 309
 310        substream->runtime->private_data = prtd;
 311
 312        return 0;
 313}
 314EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
 315
 316/**
 317 * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
 318 * @substream: PCM substream
 319 * @filter_fn: Filter function used to request the DMA channel
 320 * @filter_data: Data passed to the DMA filter function
 321 *
 322 * Returns 0 on success, a negative error code otherwise.
 323 *
 324 * This function will request a DMA channel using the passed filter function and
 325 * data. The function should usually be called from the pcm open callback. Note
 326 * that this function will use private_data field of the substream's runtime. So
 327 * it is not availabe to your pcm driver implementation.
 328 */
 329int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
 330        dma_filter_fn filter_fn, void *filter_data)
 331{
 332        return snd_dmaengine_pcm_open(substream,
 333                    snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
 334}
 335EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
 336
 337/**
 338 * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
 339 * @substream: PCM substream
 340 */
 341int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
 342{
 343        struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 344
 345        kfree(prtd);
 346
 347        return 0;
 348}
 349EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
 350
 351/**
 352 * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel
 353 * @substream: PCM substream
 354 *
 355 * Releases the DMA channel associated with the PCM substream.
 356 */
 357int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
 358{
 359        struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 360
 361        dma_release_channel(prtd->dma_chan);
 362
 363        return snd_dmaengine_pcm_close(substream);
 364}
 365EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
 366
 367MODULE_LICENSE("GPL");
 368
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