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         unsigned long flags = DMA_CTRL_ACK;
 144
 145         direction = snd_pcm_substream_to_dma_direction(substream);
 146
 147         if (!substream->runtime->no_period_wakeup)
 148                 flags |= DMA_PREP_INTERRUPT;
 149
 150         prtd->pos = 0;
 151         desc = dmaengine_prep_dma_cyclic(chan,
 152                 substream->runtime->dma_addr,
 153                 snd_pcm_lib_buffer_bytes(substream),
 154                 snd_pcm_lib_period_bytes(substream), direction, flags);
 155
 156         if (!desc)
 157                 return -ENOMEM;
 158
 159         desc->callback = dmaengine_pcm_dma_complete;
 160         desc->callback_param = substream;
 161         prtd->cookie = dmaengine_submit(desc);
 162
 163         return 0;
 164 }
 165
 166 /**
 167  * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
 168  * @substream: PCM substream
 169  * @cmd: Trigger command
 170  *
 171  * Returns 0 on success, a negative error code otherwise.
 172  *
 173  * This function can be used as the PCM trigger callback for dmaengine based PCM
 174  * driver implementations.
 175  */
 176 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 177 {
 178         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 179         int ret;
 180
 181         switch (cmd) {
 182         case SNDRV_PCM_TRIGGER_START:
 183                 ret = dmaengine_pcm_prepare_and_submit(substream);
 184                 if (ret)
 185                         return ret;
 186                 dma_async_issue_pending(prtd->dma_chan);
 187                 break;
 188         case SNDRV_PCM_TRIGGER_RESUME:
 189         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 190                 dmaengine_resume(prtd->dma_chan);
 191                 break;
 192         case SNDRV_PCM_TRIGGER_SUSPEND:
 193         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 194                 dmaengine_pause(prtd->dma_chan);
 195                 break;
 196         case SNDRV_PCM_TRIGGER_STOP:
 197                 dmaengine_terminate_all(prtd->dma_chan);
 198                 break;
 199         default:
 200                 return -EINVAL;
 201         }
 202
 203         return 0;
 204 }
 205 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
 206
 207 /**
 208  * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
 209  * @substream: PCM substream
 210  *
 211  * This function is deprecated and should not be used by new drivers, as its
 212  * results may be unreliable.
 213  */
 214 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
 215 {
 216         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 217         return bytes_to_frames(substream->runtime, prtd->pos);
 218 }
 219 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
 220
 221 /**
 222  * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
 223  * @substream: PCM substream
 224  *
 225  * This function can be used as the PCM pointer callback for dmaengine based PCM
 226  * driver implementations.
 227  */
 228 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
 229 {
 230         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 231         struct dma_tx_state state;
 232         enum dma_status status;
 233         unsigned int buf_size;
 234         unsigned int pos = 0;
 235
 236         status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
 237         if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
 238                 buf_size = snd_pcm_lib_buffer_bytes(substream);
 239                 if (state.residue > 0 && state.residue <= buf_size)
 240                         pos = buf_size - state.residue;
 241         }
 242
 243         return bytes_to_frames(substream->runtime, pos);
 244 }
 245 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
 246
 247 static int dmaengine_pcm_request_channel(struct dmaengine_pcm_runtime_data *prtd,
 248         dma_filter_fn filter_fn, void *filter_data)
 249 {
 250         dma_cap_mask_t mask;
 251
 252         dma_cap_zero(mask);
 253         dma_cap_set(DMA_SLAVE, mask);
 254         dma_cap_set(DMA_CYCLIC, mask);
 255         prtd->dma_chan = dma_request_channel(mask, filter_fn, filter_data);
 256
 257         if (!prtd->dma_chan)
 258                 return -ENXIO;
 259
 260         return 0;
 261 }
 262
 263 /**
 264  * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
 265  * @substream: PCM substream
 266  * @filter_fn: Filter function used to request the DMA channel
 267  * @filter_data: Data passed to the DMA filter function
 268  *
 269  * Returns 0 on success, a negative error code otherwise.
 270  *
 271  * This function will request a DMA channel using the passed filter function and
 272  * data. The function should usually be called from the pcm open callback.
 273  *
 274  * Note that this function will use private_data field of the substream's
 275  * runtime. So it is not availabe to your pcm driver implementation. If you need
 276  * to keep additional data attached to a substream use
 277  * snd_dmaengine_pcm_{set,get}_data.
 278  */
 279 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
 280         dma_filter_fn filter_fn, void *filter_data)
 281 {
 282         struct dmaengine_pcm_runtime_data *prtd;
 283         int ret;
 284
 285         ret = snd_pcm_hw_constraint_integer(substream->runtime,
 286                                             SNDRV_PCM_HW_PARAM_PERIODS);
 287         if (ret < 0)
 288                 return ret;
 289
 290         prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 291         if (!prtd)
 292                 return -ENOMEM;
 293
 294         ret = dmaengine_pcm_request_channel(prtd, filter_fn, filter_data);
 295         if (ret < 0) {
 296                 kfree(prtd);
 297                 return ret;
 298         }
 299
 300         substream->runtime->private_data = prtd;
 301
 302         return 0;
 303 }
 304 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
 305
 306 /**
 307  * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
 308  * @substream: PCM substream
 309  */
 310 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
 311 {
 312         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 313
 314         dma_release_channel(prtd->dma_chan);
 315         kfree(prtd);
 316
 317         return 0;
 318 }
 319 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
 320
 321 MODULE_LICENSE("GPL");