From: Stefan Binding sbinding@opensource.cirrus.com
[ Upstream commit 02b44a2b2bdcee03cbb92484d31e9ca1b91b2a38 ]
The volume control for cs42l43 speakers has a maximum gain of +31.5 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 codec or the signal path has been tuned for a particular maximum gain in the codec.
In the case of systems which use the soc_sdw_cs42l43 driver, audio will likely be distorted in all cases above 0 dB, therefore add a volume limit of 128, which is 0 dB maximum volume inside this driver.
Signed-off-by: Stefan Binding sbinding@opensource.cirrus.com Reviewed-by: Charles Keepax ckeepax@opensource.cirrus.com Link: https://patch.msgid.link/20250430103134.24579-2-sbinding@opensource.cirrus.c... Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- sound/soc/sdw_utils/soc_sdw_cs42l43.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/sound/soc/sdw_utils/soc_sdw_cs42l43.c b/sound/soc/sdw_utils/soc_sdw_cs42l43.c index adb1c008e871d..2dc7787234c36 100644 --- a/sound/soc/sdw_utils/soc_sdw_cs42l43.c +++ b/sound/soc/sdw_utils/soc_sdw_cs42l43.c @@ -20,6 +20,8 @@ #include <sound/soc-dapm.h> #include <sound/soc_sdw_utils.h>
+#define CS42L43_SPK_VOLUME_0DB 128 /* 0dB Max */ + static const struct snd_soc_dapm_route cs42l43_hs_map[] = { { "Headphone", NULL, "cs42l43 AMP3_OUT" }, { "Headphone", NULL, "cs42l43 AMP4_OUT" }, @@ -117,6 +119,14 @@ int asoc_sdw_cs42l43_spk_rtd_init(struct snd_soc_pcm_runtime *rtd, struct snd_so return -ENOMEM; }
+ ret = snd_soc_limit_volume(card, "cs42l43 Speaker Digital Volume", + CS42L43_SPK_VOLUME_0DB); + if (ret) + dev_err(card->dev, "cs42l43 speaker volume limit failed: %d\n", ret); + else + dev_info(card->dev, "Setting CS42L43 Speaker volume limit to %d\n", + CS42L43_SPK_VOLUME_0DB); + ret = snd_soc_dapm_add_routes(&card->dapm, cs42l43_spk_map, ARRAY_SIZE(cs42l43_spk_map)); if (ret)