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         dma_cookie_t cookie;
  34
  35         unsigned int pos;
  36
  37         void *data;
  38 };
  39
  40 static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
  41         const struct snd_pcm_substream *substream)
  42 {
  43         return substream->runtime->private_data;
  44 }
  45
  46 /**
  47  * snd_dmaengine_pcm_set_data - Set dmaengine substream private data
  48  * @substream: PCM substream
  49  * @data: Data to set
  50  */
  51 void snd_dmaengine_pcm_set_data(struct snd_pcm_substream *substream, void *data)
  52 {
  53         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  54
  55         prtd->data = data;
  56 }
  57 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_data);
  58
  59 /**
  60  * snd_dmaengine_pcm_get_data - Get dmaeinge substream private data
  61  * @substream: PCM substream
  62  *
  63  * Returns the data previously set with snd_dmaengine_pcm_set_data
  64  */
  65 void *snd_dmaengine_pcm_get_data(struct snd_pcm_substream *substream)
  66 {
  67         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  68
  69         return prtd->data;
  70 }
  71 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_data);
  72
  73 struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
  74 {
  75         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  76
  77         return prtd->dma_chan;
  78 }
  79 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);
  80
  81 /**
  82  * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
  83  * @substream: PCM substream
  84  * @params: hw_params
  85  * @slave_config: DMA slave config
  86  *
  87  * This function can be used to initialize a dma_slave_config from a substream
  88  * and hw_params in a dmaengine based PCM driver implementation.
  89  */
  90 int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
  91         const struct snd_pcm_hw_params *params,
  92         struct dma_slave_config *slave_config)
  93 {
  94         enum dma_slave_buswidth buswidth;
  95
  96         switch (params_format(params)) {
  97         case SNDRV_PCM_FORMAT_S8:
  98                 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
  99                 break;
 100         case SNDRV_PCM_FORMAT_S16_LE:
 101                 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
 102                 break;
 103         case SNDRV_PCM_FORMAT_S18_3LE:
 104         case SNDRV_PCM_FORMAT_S20_3LE:
 105         case SNDRV_PCM_FORMAT_S24_LE:
 106         case SNDRV_PCM_FORMAT_S32_LE:
 107                 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
 108                 break;
 109         default:
 110                 return -EINVAL;
 111         }
 112
 113         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 114                 slave_config->direction = DMA_MEM_TO_DEV;
 115                 slave_config->dst_addr_width = buswidth;
 116         } else {
 117                 slave_config->direction = DMA_DEV_TO_MEM;
 118                 slave_config->src_addr_width = buswidth;
 119         }
 120
 121         return 0;
 122 }
 123 EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
 124
 125 static void dmaengine_pcm_dma_complete(void *arg)
 126 {
 127         struct snd_pcm_substream *substream = arg;
 128         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 129
 130         prtd->pos += snd_pcm_lib_period_bytes(substream);
 131         if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
 132                 prtd->pos = 0;
 133
 134         snd_pcm_period_elapsed(substream);
 135 }
 136
 137 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
 138 {
 139         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 140         struct dma_chan *chan = prtd->dma_chan;
 141         struct dma_async_tx_descriptor *desc;
 142         enum dma_transfer_direction direction;
 143
 144         direction = snd_pcm_substream_to_dma_direction(substream);
 145
 146         prtd->pos = 0;
 147         desc = dmaengine_prep_dma_cyclic(chan,
 148                 substream->runtime->dma_addr,
 149                 snd_pcm_lib_buffer_bytes(substream),
 150                 snd_pcm_lib_period_bytes(substream), direction);
 151
 152         if (!desc)
 153                 return -ENOMEM;
 154
 155         desc->callback = dmaengine_pcm_dma_complete;
 156         desc->callback_param = substream;
 157         prtd->cookie = dmaengine_submit(desc);
 158
 159         return 0;
 160 }
 161
 162 /**
 163  * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
 164  * @substream: PCM substream
 165  * @cmd: Trigger command
 166  *
 167  * Returns 0 on success, a negative error code otherwise.
 168  *
 169  * This function can be used as the PCM trigger callback for dmaengine based PCM
 170  * driver implementations.
 171  */
 172 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 173 {
 174         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 175         int ret;
 176
 177         switch (cmd) {
 178         case SNDRV_PCM_TRIGGER_START:
 179                 ret = dmaengine_pcm_prepare_and_submit(substream);
 180                 if (ret)
 181                         return ret;
 182                 dma_async_issue_pending(prtd->dma_chan);
 183                 break;
 184         case SNDRV_PCM_TRIGGER_RESUME:
 185         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 186                 dmaengine_resume(prtd->dma_chan);
 187                 break;
 188         case SNDRV_PCM_TRIGGER_SUSPEND:
 189         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 190                 dmaengine_pause(prtd->dma_chan);
 191                 break;
 192         case SNDRV_PCM_TRIGGER_STOP:
 193                 dmaengine_terminate_all(prtd->dma_chan);
 194                 break;
 195         default:
 196                 return -EINVAL;
 197         }
 198
 199         return 0;
 200 }
 201 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
 202
 203 /**
 204  * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
 205  * @substream: PCM substream
 206  *
 207  * This function is deprecated and should not be used by new drivers, as its
 208  * results may be unreliable.
 209  */
 210 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
 211 {
 212         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 213         return bytes_to_frames(substream->runtime, prtd->pos);
 214 }
 215 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
 216
 217 /**
 218  * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
 219  * @substream: PCM substream
 220  *
 221  * This function can be used as the PCM pointer callback for dmaengine based PCM
 222  * driver implementations.
 223  */
 224 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
 225 {
 226         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 227         struct dma_tx_state state;
 228         enum dma_status status;
 229         unsigned int buf_size;
 230         unsigned int pos = 0;
 231
 232         status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
 233         if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
 234                 buf_size = snd_pcm_lib_buffer_bytes(substream);
 235                 if (state.residue > 0 && state.residue <= buf_size)
 236                         pos = buf_size - state.residue;
 237         }
 238
 239         return bytes_to_frames(substream->runtime, pos);
 240 }
 241 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
 242
 243 static int dmaengine_pcm_request_channel(struct dmaengine_pcm_runtime_data *prtd,
 244         dma_filter_fn filter_fn, void *filter_data)
 245 {
 246         dma_cap_mask_t mask;
 247
 248         dma_cap_zero(mask);
 249         dma_cap_set(DMA_SLAVE, mask);
 250         dma_cap_set(DMA_CYCLIC, mask);
 251         prtd->dma_chan = dma_request_channel(mask, filter_fn, filter_data);
 252
 253         if (!prtd->dma_chan)
 254                 return -ENXIO;
 255
 256         return 0;
 257 }
 258
 259 /**
 260  * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
 261  * @substream: PCM substream
 262  * @filter_fn: Filter function used to request the DMA channel
 263  * @filter_data: Data passed to the DMA filter function
 264  *
 265  * Returns 0 on success, a negative error code otherwise.
 266  *
 267  * This function will request a DMA channel using the passed filter function and
 268  * data. The function should usually be called from the pcm open callback.
 269  *
 270  * Note that this function will use private_data field of the substream's
 271  * runtime. So it is not availabe to your pcm driver implementation. If you need
 272  * to keep additional data attached to a substream use
 273  * snd_dmaengine_pcm_{set,get}_data.
 274  */
 275 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
 276         dma_filter_fn filter_fn, void *filter_data)
 277 {
 278         struct dmaengine_pcm_runtime_data *prtd;
 279         int ret;
 280
 281         ret = snd_pcm_hw_constraint_integer(substream->runtime,
 282                                             SNDRV_PCM_HW_PARAM_PERIODS);
 283         if (ret < 0)
 284                 return ret;
 285
 286         prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 287         if (!prtd)
 288                 return -ENOMEM;
 289
 290         ret = dmaengine_pcm_request_channel(prtd, filter_fn, filter_data);
 291         if (ret < 0) {
 292                 kfree(prtd);
 293                 return ret;
 294         }
 295
 296         substream->runtime->private_data = prtd;
 297
 298         return 0;
 299 }
 300 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
 301
 302 /**
 303  * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
 304  * @substream: PCM substream
 305  */
 306 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
 307 {
 308         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 309
 310         dma_release_channel(prtd->dma_chan);
 311         kfree(prtd);
 312
 313         return 0;
 314 }
 315 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);