Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d1e1406c authored by Lars-Peter Clausen's avatar Lars-Peter Clausen Committed by Mark Brown
Browse files

ASoC: generic-dmaengine-pcm: Add support for half-duplex 



Some platforms which are half-duplex share the same DMA channel between the
playback and capture stream. Add support for this to the generic dmaengine PCM
driver.

Signed-off-by: default avatarLars-Peter Clausen <lars@metafoo.de>
Tested-by: default avatarShawn Guo <shawn.guo@linaro.org>
Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
parent 22f38f79

include/sound/dmaengine_pcm.h

+5 −0
Original line number Diff line number Diff line
@@ -91,6 +91,11 @@ void snd_dmaengine_pcm_set_config_from_dai_data( 
 * bytes that are still left to transfer.

 */

#define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(2)

/*

 * The PCM is half duplex and the DMA channel is shared between capture and

 * playback.

 */

#define SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX BIT(3)



/**

 * struct snd_dmaengine_pcm_config - Configuration data for dmaengine based PCM

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

+30 −13
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ struct dmaengine_pcm { 
	struct dma_chan *chan[SNDRV_PCM_STREAM_CAPTURE + 1];

	const struct snd_dmaengine_pcm_config *config;

	struct snd_soc_platform platform;

	bool compat;

	unsigned int flags;

};



static struct dmaengine_pcm *soc_platform_to_pcm(struct snd_soc_platform *p)
@@ -128,6 +128,9 @@ static struct dma_chan *dmaengine_pcm_compat_request_channel( 
{

	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);



	if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])

		return pcm->chan[0];



	if (pcm->config->compat_request_channel)

		return pcm->config->compat_request_channel(rtd, substream);
@@ -148,7 +151,7 @@ static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd) 
		if (!substream)

			continue;



		if (!pcm->chan[i] && pcm->compat) {

		if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {

			pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd,

				substream);

		}
@@ -215,6 +218,25 @@ static const char * const dmaengine_pcm_dma_channel_names[] = { 
	[SNDRV_PCM_STREAM_CAPTURE] = "rx",

};



static void dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,

	struct device_node *of_node)

{

	unsigned int i;



	if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || !of_node)

		return;



	if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) {

		pcm->chan[0] = of_dma_request_slave_channel(of_node, "tx_rx");

		pcm->chan[1] = pcm->chan[0];

	} else {

		for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {

			pcm->chan[i] = of_dma_request_slave_channel(of_node,

					dmaengine_pcm_dma_channel_names[i]);

		}

	}

}



/**

 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device

 * @dev: The parent device for the PCM device
@@ -225,23 +247,15 @@ int snd_dmaengine_pcm_register(struct device *dev, 
	const struct snd_dmaengine_pcm_config *config, unsigned int flags)

{

	struct dmaengine_pcm *pcm;

	unsigned int i;



	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);

	if (!pcm)

		return -ENOMEM;



	pcm->config = config;

	pcm->flags = flags;



	if (flags & SND_DMAENGINE_PCM_FLAG_COMPAT)

		pcm->compat = true;



	if (!(flags & SND_DMAENGINE_PCM_FLAG_NO_DT) && dev->of_node) {

		for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {

			pcm->chan[i] = of_dma_request_slave_channel(dev->of_node,

					dmaengine_pcm_dma_channel_names[i]);

		}

	}

	dmaengine_pcm_request_chan_of(pcm, dev->of_node);



	if (flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)

		return snd_soc_add_platform(dev, &pcm->platform,
@@ -272,8 +286,11 @@ void snd_dmaengine_pcm_unregister(struct device *dev) 
	pcm = soc_platform_to_pcm(platform);



	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {

		if (pcm->chan[i])

		if (pcm->chan[i]) {

			dma_release_channel(pcm->chan[i]);

			if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)

				break;

		}

	}



	snd_soc_remove_platform(platform);