From: Stefan Binding sbinding@opensource.cirrus.com
[ Upstream commit d5463e531c128ff1b141fdba2e13345cd50028a4 ]
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: Stefan Binding sbinding@opensource.cirrus.com Link: https://patch.msgid.link/20250430103134.24579-3-sbinding@opensource.cirrus.c... Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/sound/soc_sdw_utils.h | 1 + sound/soc/sdw_utils/soc_sdw_bridge_cs35l56.c | 4 ++++ sound/soc/sdw_utils/soc_sdw_cs_amp.c | 24 ++++++++++++++++++++ 3 files changed, 29 insertions(+)
diff --git a/include/sound/soc_sdw_utils.h b/include/sound/soc_sdw_utils.h index 36a4a1e1d8ca2..d8bd5d37131aa 100644 --- a/include/sound/soc_sdw_utils.h +++ b/include/sound/soc_sdw_utils.h @@ -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, diff --git a/sound/soc/sdw_utils/soc_sdw_bridge_cs35l56.c b/sound/soc/sdw_utils/soc_sdw_bridge_cs35l56.c index 246e5c2e0af55..c7e55f4433514 100644 --- a/sound/soc/sdw_utils/soc_sdw_bridge_cs35l56.c +++ b/sound/soc/sdw_utils/soc_sdw_bridge_cs35l56.c @@ -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; diff --git a/sound/soc/sdw_utils/soc_sdw_cs_amp.c b/sound/soc/sdw_utils/soc_sdw_cs_amp.c index 4b6181cf29716..35b550bcd4ded 100644 --- a/sound/soc/sdw_utils/soc_sdw_cs_amp.c +++ b/sound/soc/sdw_utils/soc_sdw_cs_amp.c @@ -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;