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
  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
  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 }
  96 EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
  97
  98 static void dmaengine_pcm_dma_complete(void *arg)
  99 {
 100         struct snd_pcm_substream *substream = arg;
 101         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 102
 103         prtd->pos += snd_pcm_lib_period_bytes(substream);
 104         if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
 105                 prtd->pos = 0;
 106
 107         snd_pcm_period_elapsed(substream);
 108 }
 109
 110 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
 111 {
 112         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 113         struct dma_chan *chan = prtd->dma_chan;
 114         struct dma_async_tx_descriptor *desc;
 115         enum dma_transfer_direction direction;
 116         unsigned long flags = DMA_CTRL_ACK;
 117
 118         direction = snd_pcm_substream_to_dma_direction(substream);
 119
 120         if (!substream->runtime->no_period_wakeup)
 121                 flags |= DMA_PREP_INTERRUPT;
 122
 123         prtd->pos = 0;
 124         desc = dmaengine_prep_dma_cyclic(chan,
 125                 substream->runtime->dma_addr,
 126                 snd_pcm_lib_buffer_bytes(substream),
 127                 snd_pcm_lib_period_bytes(substream), direction, flags);
 128
 129         if (!desc)
 130                 return -ENOMEM;
 131
 132         desc->callback = dmaengine_pcm_dma_complete;
 133         desc->callback_param = substream;
 134         prtd->cookie = dmaengine_submit(desc);
 135
 136         return 0;
 137 }
 138
 139 /**
 140  * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
 141  * @substream: PCM substream
 142  * @cmd: Trigger command
 143  *
 144  * Returns 0 on success, a negative error code otherwise.
 145  *
 146  * This function can be used as the PCM trigger callback for dmaengine based PCM
 147  * driver implementations.
 148  */
 149 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 150 {
 151         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 152         int ret;
 153
 154         switch (cmd) {
 155         case SNDRV_PCM_TRIGGER_START:
 156                 ret = dmaengine_pcm_prepare_and_submit(substream);
 157                 if (ret)
 158                         return ret;
 159                 dma_async_issue_pending(prtd->dma_chan);
 160                 break;
 161         case SNDRV_PCM_TRIGGER_RESUME:
 162         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 163                 dmaengine_resume(prtd->dma_chan);
 164                 break;
 165         case SNDRV_PCM_TRIGGER_SUSPEND:
 166         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 167                 dmaengine_pause(prtd->dma_chan);
 168                 break;
 169         case SNDRV_PCM_TRIGGER_STOP:
 170                 dmaengine_terminate_all(prtd->dma_chan);
 171                 break;
 172         default:
 173                 return -EINVAL;
 174         }
 175
 176         return 0;
 177 }
 178 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
 179
 180 /**
 181  * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
 182  * @substream: PCM substream
 183  *
 184  * This function is deprecated and should not be used by new drivers, as its
 185  * results may be unreliable.
 186  */
 187 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
 188 {
 189         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 190         return bytes_to_frames(substream->runtime, prtd->pos);
 191 }
 192 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
 193
 194 /**
 195  * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
 196  * @substream: PCM substream
 197  *
 198  * This function can be used as the PCM pointer callback for dmaengine based PCM
 199  * driver implementations.
 200  */
 201 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
 202 {
 203         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 204         struct dma_tx_state state;
 205         enum dma_status status;
 206         unsigned int buf_size;
 207         unsigned int pos = 0;
 208
 209         status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
 210         if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
 211                 buf_size = snd_pcm_lib_buffer_bytes(substream);
 212                 if (state.residue > 0 && state.residue <= buf_size)
 213                         pos = buf_size - state.residue;
 214         }
 215
 216         return bytes_to_frames(substream->runtime, pos);
 217 }
 218 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
 219
 220 static int dmaengine_pcm_request_channel(struct dmaengine_pcm_runtime_data *prtd,
 221         dma_filter_fn filter_fn, void *filter_data)
 222 {
 223         dma_cap_mask_t mask;
 224
 225         dma_cap_zero(mask);
 226         dma_cap_set(DMA_SLAVE, mask);
 227         dma_cap_set(DMA_CYCLIC, mask);
 228         prtd->dma_chan = dma_request_channel(mask, filter_fn, filter_data);
 229
 230         if (!prtd->dma_chan)
 231                 return -ENXIO;
 232
 233         return 0;
 234 }
 235
 236 /**
 237  * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
 238  * @substream: PCM substream
 239  * @filter_fn: Filter function used to request the DMA channel
 240  * @filter_data: Data passed to the DMA filter function
 241  *
 242  * Returns 0 on success, a negative error code otherwise.
 243  *
 244  * This function will request a DMA channel using the passed filter function and
 245  * data. The function should usually be called from the pcm open callback.
 246  *
 247  * Note that this function will use private_data field of the substream's
 248  * runtime. So it is not availabe to your pcm driver implementation. If you need
 249  * to keep additional data attached to a substream use
 250  * snd_dmaengine_pcm_{set,get}_data.
 251  */
 252 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
 253         dma_filter_fn filter_fn, void *filter_data)
 254 {
 255         struct dmaengine_pcm_runtime_data *prtd;
 256         int ret;
 257
 258         ret = snd_pcm_hw_constraint_integer(substream->runtime,
 259                                             SNDRV_PCM_HW_PARAM_PERIODS);
 260         if (ret < 0)
 261                 return ret;
 262
 263         prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 264         if (!prtd)
 265                 return -ENOMEM;
 266
 267         ret = dmaengine_pcm_request_channel(prtd, filter_fn, filter_data);
 268         if (ret < 0) {
 269                 kfree(prtd);
 270                 return ret;
 271         }
 272
 273         substream->runtime->private_data = prtd;
 274
 275         return 0;
 276 }
 277 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
 278
 279 /**
 280  * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
 281  * @substream: PCM substream
 282  */
 283 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
 284 {
 285         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 286
 287         dma_release_channel(prtd->dma_chan);
 288         kfree(prtd);
 289
 290         return 0;
 291 }
 292 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
 293
 294 MODULE_LICENSE("GPL");