sound/soc/soc-generic-dmaengine-pcm.c

   1 /*
   2  *  Copyright (C) 2013, Analog Devices Inc.
   3  *      Author: Lars-Peter Clausen <lars@metafoo.de>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify it
   6  *  under  the terms of the GNU General  Public License as published by the
   7  *  Free Software Foundation;  either version 2 of the License, or (at your
   8  *  option) any later version.
   9  *
  10  *  You should have received a copy of the GNU General Public License along
  11  *  with this program; if not, write to the Free Software Foundation, Inc.,
  12  *  675 Mass Ave, Cambridge, MA 02139, USA.
  13  *
  14  */
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/dmaengine.h>
  18 #include <linux/slab.h>
  19 #include <sound/pcm.h>
  20 #include <sound/pcm_params.h>
  21 #include <sound/soc.h>
  22 #include <linux/dma-mapping.h>
  23 #include <linux/of.h>
  24
  25 #include <sound/dmaengine_pcm.h>
  26
  27 struct dmaengine_pcm {
  28         struct dma_chan *chan[SNDRV_PCM_STREAM_CAPTURE + 1];
  29         const struct snd_dmaengine_pcm_config *config;
  30         struct snd_soc_platform platform;
  31         unsigned int flags;
  32 };
  33
  34 static struct dmaengine_pcm *soc_platform_to_pcm(struct snd_soc_platform *p)
  35 {
  36         return container_of(p, struct dmaengine_pcm, platform);
  37 }
  38
  39 /**
  40  * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback
  41  * @substream: PCM substream
  42  * @params: hw_params
  43  * @slave_config: DMA slave config to prepare
  44  *
  45  * This function can be used as a generic prepare_slave_config callback for
  46  * platforms which make use of the snd_dmaengine_dai_dma_data struct for their
  47  * DAI DMA data. Internally the function will first call
  48  * snd_hwparams_to_dma_slave_config to fill in the slave config based on the
  49  * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the
  50  * remaining fields based on the DAI DMA data.
  51  */
  52 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
  53         struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
  54 {
  55         struct snd_soc_pcm_runtime *rtd = substream->private_data;
  56         struct snd_dmaengine_dai_dma_data *dma_data;
  57         int ret;
  58
  59         dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
  60
  61         ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
  62         if (ret)
  63                 return ret;
  64
  65         snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data,
  66                 slave_config);
  67
  68         return 0;
  69 }
  70 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);
  71
  72 static int dmaengine_pcm_hw_params(struct snd_pcm_substream *substream,
  73         struct snd_pcm_hw_params *params)
  74 {
  75         struct snd_soc_pcm_runtime *rtd = substream->private_data;
  76         struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
  77         struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
  78         struct dma_slave_config slave_config;
  79         int ret;
  80
  81         if (pcm->config->prepare_slave_config) {
  82                 ret = pcm->config->prepare_slave_config(substream, params,
  83                                 &slave_config);
  84                 if (ret)
  85                         return ret;
  86
  87                 ret = dmaengine_slave_config(chan, &slave_config);
  88                 if (ret)
  89                         return ret;
  90         }
  91
  92         return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
  93 }
  94
  95 static int dmaengine_pcm_open(struct snd_pcm_substream *substream)
  96 {
  97         struct snd_soc_pcm_runtime *rtd = substream->private_data;
  98         struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
  99         struct dma_chan *chan = pcm->chan[substream->stream];
 100         int ret;
 101
 102         ret = snd_soc_set_runtime_hwparams(substream,
 103                                 pcm->config->pcm_hardware);
 104         if (ret)
 105                 return ret;
 106
 107         return snd_dmaengine_pcm_open(substream, chan);
 108 }
 109
 110 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm,
 111         struct snd_pcm_substream *substream)
 112 {
 113         if (!pcm->chan[substream->stream])
 114                 return NULL;
 115
 116         return pcm->chan[substream->stream]->device->dev;
 117 }
 118
 119 static void dmaengine_pcm_free(struct snd_pcm *pcm)
 120 {
 121         snd_pcm_lib_preallocate_free_for_all(pcm);
 122 }
 123
 124 static struct dma_chan *dmaengine_pcm_compat_request_channel(
 125         struct snd_soc_pcm_runtime *rtd,
 126         struct snd_pcm_substream *substream)
 127 {
 128         struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
 129
 130         if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
 131                 return pcm->chan[0];
 132
 133         if (pcm->config->compat_request_channel)
 134                 return pcm->config->compat_request_channel(rtd, substream);
 135
 136         return snd_dmaengine_pcm_request_channel(pcm->config->compat_filter_fn,
 137                 snd_soc_dai_get_dma_data(rtd->cpu_dai, substream));
 138 }
 139
 140 static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
 141 {
 142         struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
 143         const struct snd_dmaengine_pcm_config *config = pcm->config;
 144         struct snd_pcm_substream *substream;
 145         unsigned int i;
 146         int ret;
 147
 148         for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
 149                 substream = rtd->pcm->streams[i].substream;
 150                 if (!substream)
 151                         continue;
 152
 153                 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
 154                         pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd,
 155                                 substream);
 156                 }
 157
 158                 if (!pcm->chan[i]) {
 159                         dev_err(rtd->platform->dev,
 160                                 "Missing dma channel for stream: %d\n", i);
 161                         ret = -EINVAL;
 162                         goto err_free;
 163                 }
 164
 165                 ret = snd_pcm_lib_preallocate_pages(substream,
 166                                 SNDRV_DMA_TYPE_DEV,
 167                                 dmaengine_dma_dev(pcm, substream),
 168                                 config->prealloc_buffer_size,
 169                                 config->pcm_hardware->buffer_bytes_max);
 170                 if (ret)
 171                         goto err_free;
 172         }
 173
 174         return 0;
 175
 176 err_free:
 177         dmaengine_pcm_free(rtd->pcm);
 178         return ret;
 179 }
 180
 181 static const struct snd_pcm_ops dmaengine_pcm_ops = {
 182         .open           = dmaengine_pcm_open,
 183         .close          = snd_dmaengine_pcm_close,
 184         .ioctl          = snd_pcm_lib_ioctl,
 185         .hw_params      = dmaengine_pcm_hw_params,
 186         .hw_free        = snd_pcm_lib_free_pages,
 187         .trigger        = snd_dmaengine_pcm_trigger,
 188         .pointer        = snd_dmaengine_pcm_pointer,
 189 };
 190
 191 static const struct snd_soc_platform_driver dmaengine_pcm_platform = {
 192         .ops            = &dmaengine_pcm_ops,
 193         .pcm_new        = dmaengine_pcm_new,
 194         .pcm_free       = dmaengine_pcm_free,
 195         .probe_order    = SND_SOC_COMP_ORDER_LATE,
 196 };
 197
 198 static const struct snd_pcm_ops dmaengine_no_residue_pcm_ops = {
 199         .open           = dmaengine_pcm_open,
 200         .close          = snd_dmaengine_pcm_close,
 201         .ioctl          = snd_pcm_lib_ioctl,
 202         .hw_params      = dmaengine_pcm_hw_params,
 203         .hw_free        = snd_pcm_lib_free_pages,
 204         .trigger        = snd_dmaengine_pcm_trigger,
 205         .pointer        = snd_dmaengine_pcm_pointer_no_residue,
 206 };
 207
 208 static const struct snd_soc_platform_driver dmaengine_no_residue_pcm_platform = {
 209         .ops            = &dmaengine_no_residue_pcm_ops,
 210         .pcm_new        = dmaengine_pcm_new,
 211         .pcm_free       = dmaengine_pcm_free,
 212         .probe_order    = SND_SOC_COMP_ORDER_LATE,
 213 };
 214
 215 static const char * const dmaengine_pcm_dma_channel_names[] = {
 216         [SNDRV_PCM_STREAM_PLAYBACK] = "tx",
 217         [SNDRV_PCM_STREAM_CAPTURE] = "rx",
 218 };
 219
 220 static void dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
 221         struct device *dev)
 222 {
 223         unsigned int i;
 224
 225         if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || !dev->of_node)
 226                 return;
 227
 228         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) {
 229                 pcm->chan[0] = dma_request_slave_channel(dev, "rx-tx");
 230                 pcm->chan[1] = pcm->chan[0];
 231         } else {
 232                 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
 233                         pcm->chan[i] = dma_request_slave_channel(dev,
 234                                         dmaengine_pcm_dma_channel_names[i]);
 235                 }
 236         }
 237 }
 238
 239 /**
 240  * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
 241  * @dev: The parent device for the PCM device
 242  * @config: Platform specific PCM configuration
 243  * @flags: Platform specific quirks
 244  */
 245 int snd_dmaengine_pcm_register(struct device *dev,
 246         const struct snd_dmaengine_pcm_config *config, unsigned int flags)
 247 {
 248         struct dmaengine_pcm *pcm;
 249
 250         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 251         if (!pcm)
 252                 return -ENOMEM;
 253
 254         pcm->config = config;
 255         pcm->flags = flags;
 256
 257         dmaengine_pcm_request_chan_of(pcm, dev);
 258
 259         if (flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
 260                 return snd_soc_add_platform(dev, &pcm->platform,
 261                                 &dmaengine_no_residue_pcm_platform);
 262         else
 263                 return snd_soc_add_platform(dev, &pcm->platform,
 264                                 &dmaengine_pcm_platform);
 265 }
 266 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
 267
 268 /**
 269  * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
 270  * @dev: Parent device the PCM was register with
 271  *
 272  * Removes a dmaengine based PCM device previously registered with
 273  * snd_dmaengine_pcm_register.
 274  */
 275 void snd_dmaengine_pcm_unregister(struct device *dev)
 276 {
 277         struct snd_soc_platform *platform;
 278         struct dmaengine_pcm *pcm;
 279         unsigned int i;
 280
 281         platform = snd_soc_lookup_platform(dev);
 282         if (!platform)
 283                 return;
 284
 285         pcm = soc_platform_to_pcm(platform);
 286
 287         for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
 288                 if (pcm->chan[i]) {
 289                         dma_release_channel(pcm->chan[i]);
 290                         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 291                                 break;
 292                 }
 293         }
 294
 295         snd_soc_remove_platform(platform);
 296         kfree(pcm);
 297 }
 298 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
 299
 300 MODULE_LICENSE("GPL");