Unverified Commit d5463e53 authored by Stefan Binding's avatar Stefan Binding Committed by Mark Brown
Browse files

ASoC: intel/sdw_utils: Add volume limit to cs35l56 speakers 



The volume control for cs35l56 speakers has a maximum gain of +12 dB.
However, for many use cases, this can cause distorted audio, depending
various factors, such as other signal-processing elements in the chain,
for example if the audio passes through a gain control before reaching
the amp or the signal path has been tuned for a particular maximum
gain in the amp.

In the case of systems which use the soc_sdw_* driver, audio will
likely be distorted in all cases above 0 dB, therefore add a volume
limit of 400, which is 0 dB maximum volume inside this driver.

The volume limit should be applied to both soundwire and soundwire
bridge configurations.

Signed-off-by: default avatarStefan Binding <sbinding@opensource.cirrus.com>
Link: https://patch.msgid.link/20250430103134.24579-3-sbinding@opensource.cirrus.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 02b44a2b

include/sound/soc_sdw_utils.h

+1 −0
Original line number Diff line number Diff line
@@ -226,6 +226,7 @@ int asoc_sdw_cs_amp_init(struct snd_soc_card *card, 
			 bool playback);

int asoc_sdw_cs_spk_feedback_rtd_init(struct snd_soc_pcm_runtime *rtd,

				      struct snd_soc_dai *dai);

int asoc_sdw_cs35l56_volume_limit(struct snd_soc_card *card, const char *name_prefix);



/* MAXIM codec support */

int asoc_sdw_maxim_init(struct snd_soc_card *card,

sound/soc/sdw_utils/soc_sdw_bridge_cs35l56.c

+4 −0
Original line number Diff line number Diff line
@@ -60,6 +60,10 @@ static int asoc_sdw_bridge_cs35l56_asp_init(struct snd_soc_pcm_runtime *rtd) 


	/* 4 x 16-bit sample slots and FSYNC=48000, BCLK=3.072 MHz */

	for_each_rtd_codec_dais(rtd, i, codec_dai) {

		ret = asoc_sdw_cs35l56_volume_limit(card, codec_dai->component->name_prefix);

		if (ret)

			return ret;



		ret = snd_soc_dai_set_tdm_slot(codec_dai, tx_mask, rx_mask, 4, 16);

		if (ret < 0)

			return ret;

sound/soc/sdw_utils/soc_sdw_cs_amp.c

+24 −0
Original line number Diff line number Diff line
@@ -16,6 +16,25 @@ 


#define CODEC_NAME_SIZE	8

#define CS_AMP_CHANNELS_PER_AMP	4

#define CS35L56_SPK_VOLUME_0DB 400 /* 0dB Max */



int asoc_sdw_cs35l56_volume_limit(struct snd_soc_card *card, const char *name_prefix)

{

	char *volume_ctl_name;

	int ret;



	volume_ctl_name = kasprintf(GFP_KERNEL, "%s Speaker Volume", name_prefix);

	if (!volume_ctl_name)

		return -ENOMEM;



	ret = snd_soc_limit_volume(card, volume_ctl_name, CS35L56_SPK_VOLUME_0DB);

	if (ret)

		dev_err(card->dev, "%s limit set failed: %d\n", volume_ctl_name, ret);



	kfree(volume_ctl_name);

	return ret;

}

EXPORT_SYMBOL_NS(asoc_sdw_cs35l56_volume_limit, "SND_SOC_SDW_UTILS");



int asoc_sdw_cs_spk_rtd_init(struct snd_soc_pcm_runtime *rtd, struct snd_soc_dai *dai)

{
@@ -40,6 +59,11 @@ int asoc_sdw_cs_spk_rtd_init(struct snd_soc_pcm_runtime *rtd, struct snd_soc_dai 


		snprintf(widget_name, sizeof(widget_name), "%s SPK",

			 codec_dai->component->name_prefix);



		ret = asoc_sdw_cs35l56_volume_limit(card, codec_dai->component->name_prefix);

		if (ret)

			return ret;



		ret = snd_soc_dapm_add_routes(&card->dapm, &route, 1);

		if (ret)

			return ret;