sound/soc/soc-dmaengine-pcm.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
  34         unsigned int pos;
  35
  36         void *data;
  37 };
  38
  39 static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
  40         const struct snd_pcm_substream *substream)
  41 {
  42         return substream->runtime->private_data;
  43 }
  44
  45 /**
  46  * snd_dmaengine_pcm_set_data - Set dmaengine substream private data
  47  * @substream: PCM substream
  48  * @data: Data to set
  49  */
  50 void snd_dmaengine_pcm_set_data(struct snd_pcm_substream *substream, void *data)
  51 {
  52         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  53
  54         prtd->data = data;
  55 }
  56 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_data);
  57
  58 /**
  59  * snd_dmaengine_pcm_get_data - Get dmaeinge substream private data
  60  * @substream: PCM substream
  61  *
  62  * Returns the data previously set with snd_dmaengine_pcm_set_data
  63  */
  64 void *snd_dmaengine_pcm_get_data(struct snd_pcm_substream *substream)
  65 {
  66         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  67
  68         return prtd->data;
  69 }
  70 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_data);
  71
  72 struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
  73 {
  74         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  75
  76         return prtd->dma_chan;
  77 }
  78 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);
  79
  80 /**
  81  * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
  82  * @substream: PCM substream
  83  * @params: hw_params
  84  * @slave_config: DMA slave config
  85  *
  86  * This function can be used to initialize a dma_slave_config from a substream
  87  * and hw_params in a dmaengine based PCM driver implementation.
  88  */
  89 int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
  90         const struct snd_pcm_hw_params *params,
  91         struct dma_slave_config *slave_config)
  92 {
  93         enum dma_slave_buswidth buswidth;
  94
  95         switch (params_format(params)) {
  96         case SNDRV_PCM_FORMAT_S8:
  97                 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
  98                 break;
  99         case SNDRV_PCM_FORMAT_S16_LE:
 100                 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
 101                 break;
 102         case SNDRV_PCM_FORMAT_S18_3LE:
 103         case SNDRV_PCM_FORMAT_S20_3LE:
 104         case SNDRV_PCM_FORMAT_S24_LE:
 105         case SNDRV_PCM_FORMAT_S32_LE:
 106                 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
 107                 break;
 108         default:
 109                 return -EINVAL;
 110         }
 111
 112         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 113                 slave_config->direction = DMA_MEM_TO_DEV;
 114                 slave_config->dst_addr_width = buswidth;
 115         } else {
 116                 slave_config->direction = DMA_DEV_TO_MEM;
 117                 slave_config->src_addr_width = buswidth;
 118         }
 119
 120         return 0;
 121 }
 122 EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
 123
 124 static void dmaengine_pcm_dma_complete(void *arg)
 125 {
 126         struct snd_pcm_substream *substream = arg;
 127         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 128
 129         prtd->pos += snd_pcm_lib_period_bytes(substream);
 130         if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
 131                 prtd->pos = 0;
 132
 133         snd_pcm_period_elapsed(substream);
 134 }
 135
 136 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
 137 {
 138         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 139         struct dma_chan *chan = prtd->dma_chan;
 140         struct dma_async_tx_descriptor *desc;
 141         enum dma_transfer_direction direction;
 142
 143         direction = snd_pcm_substream_to_dma_direction(substream);
 144
 145         prtd->pos = 0;
 146         desc = dmaengine_prep_dma_cyclic(chan,
 147                 substream->runtime->dma_addr,
 148                 snd_pcm_lib_buffer_bytes(substream),
 149                 snd_pcm_lib_period_bytes(substream), direction);
 150
 151         if (!desc)
 152                 return -ENOMEM;
 153
 154         desc->callback = dmaengine_pcm_dma_complete;
 155         desc->callback_param = substream;
 156         dmaengine_submit(desc);
 157
 158         return 0;
 159 }
 160
 161 /**
 162  * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
 163  * @substream: PCM substream
 164  * @cmd: Trigger command
 165  *
 166  * Returns 0 on success, a negative error code otherwise.
 167  *
 168  * This function can be used as the PCM trigger callback for dmaengine based PCM
 169  * driver implementations.
 170  */
 171 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 172 {
 173         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 174         int ret;
 175
 176         switch (cmd) {
 177         case SNDRV_PCM_TRIGGER_START:
 178                 ret = dmaengine_pcm_prepare_and_submit(substream);
 179                 if (ret)
 180                         return ret;
 181                 dma_async_issue_pending(prtd->dma_chan);
 182                 break;
 183         case SNDRV_PCM_TRIGGER_RESUME:
 184         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 185                 dmaengine_resume(prtd->dma_chan);
 186                 break;
 187         case SNDRV_PCM_TRIGGER_SUSPEND:
 188         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 189                 dmaengine_pause(prtd->dma_chan);
 190                 break;
 191         case SNDRV_PCM_TRIGGER_STOP:
 192                 dmaengine_terminate_all(prtd->dma_chan);
 193                 break;
 194         default:
 195                 return -EINVAL;
 196         }
 197
 198         return 0;
 199 }
 200 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
 201
 202 /**
 203  * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
 204  * @substream: PCM substream
 205  *
 206  * This function can be used as the PCM pointer callback for dmaengine based PCM
 207  * driver implementations.
 208  */
 209 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
 210 {
 211         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 212         return bytes_to_frames(substream->runtime, prtd->pos);
 213 }
 214 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
 215
 216 static int dmaengine_pcm_request_channel(struct dmaengine_pcm_runtime_data *prtd,
 217         dma_filter_fn filter_fn, void *filter_data)
 218 {
 219         dma_cap_mask_t mask;
 220
 221         dma_cap_zero(mask);
 222         dma_cap_set(DMA_SLAVE, mask);
 223         dma_cap_set(DMA_CYCLIC, mask);
 224         prtd->dma_chan = dma_request_channel(mask, filter_fn, filter_data);
 225
 226         if (!prtd->dma_chan)
 227                 return -ENXIO;
 228
 229         return 0;
 230 }
 231
 232 /**
 233  * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
 234  * @substream: PCM substream
 235  * @filter_fn: Filter function used to request the DMA channel
 236  * @filter_data: Data passed to the DMA filter function
 237  *
 238  * Returns 0 on success, a negative error code otherwise.
 239  *
 240  * This function will request a DMA channel using the passed filter function and
 241  * data. The function should usually be called from the pcm open callback.
 242  *
 243  * Note that this function will use private_data field of the substream's
 244  * runtime. So it is not availabe to your pcm driver implementation. If you need
 245  * to keep additional data attached to a substream use
 246  * snd_dmaeinge_pcm_{set,get}_data.
 247  */
 248 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
 249         dma_filter_fn filter_fn, void *filter_data)
 250 {
 251         struct dmaengine_pcm_runtime_data *prtd;
 252         int ret;
 253
 254         ret = snd_pcm_hw_constraint_integer(substream->runtime,
 255                                             SNDRV_PCM_HW_PARAM_PERIODS);
 256         if (ret < 0)
 257                 return ret;
 258
 259         prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 260         if (!prtd)
 261                 return -ENOMEM;
 262
 263         ret = dmaengine_pcm_request_channel(prtd, filter_fn, filter_data);
 264         if (ret < 0) {
 265                 kfree(prtd);
 266                 return ret;
 267         }
 268
 269         substream->runtime->private_data = prtd;
 270
 271         return 0;
 272 }
 273 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
 274
 275 /**
 276  * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
 277  * @substream: PCM substream
 278  */
 279 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
 280 {
 281         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 282
 283         dma_release_channel(prtd->dma_chan);
 284         kfree(prtd);
 285
 286         return 0;
 287 }
 288 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);