From: Valerio Setti Date: Mon, 6 Oct 2025 22:12:19 +0000 (+0200) Subject: ASoC: meson: aiu-encoder-i2s: fix bit clock polarity X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=4c4ed5e073a923fb3323022e1131cb51ad8df7a0;p=users%2Fhch%2Fmisc.git ASoC: meson: aiu-encoder-i2s: fix bit clock polarity According to I2S specs audio data is sampled on the rising edge of the clock and it can change on the falling one. When operating in normal mode this SoC behaves the opposite so a clock polarity inversion is required in this case. This was tested on an OdroidC2 (Amlogic S905 SoC) board. Signed-off-by: Valerio Setti Reviewed-by: Jerome Brunet Tested-by: Jerome Brunet Link: https://patch.msgid.link/20251007-fix-i2s-polarity-v1-1-86704d9cda10@baylibre.com Signed-off-by: Mark Brown --- diff --git a/sound/soc/meson/aiu-encoder-i2s.c b/sound/soc/meson/aiu-encoder-i2s.c index a0dd914c8ed1..3b4061508c18 100644 --- a/sound/soc/meson/aiu-encoder-i2s.c +++ b/sound/soc/meson/aiu-encoder-i2s.c @@ -236,8 +236,12 @@ static int aiu_encoder_i2s_set_fmt(struct snd_soc_dai *dai, unsigned int fmt) inv == SND_SOC_DAIFMT_IB_IF) val |= AIU_CLK_CTRL_LRCLK_INVERT; - if (inv == SND_SOC_DAIFMT_IB_NF || - inv == SND_SOC_DAIFMT_IB_IF) + /* + * The SoC changes data on the rising edge of the bitclock + * so an inversion of the bitclock is required in normal mode + */ + if (inv == SND_SOC_DAIFMT_NB_NF || + inv == SND_SOC_DAIFMT_NB_IF) val |= AIU_CLK_CTRL_AOCLK_INVERT; /* Signal skew */ @@ -328,4 +332,3 @@ const struct snd_soc_dai_ops aiu_encoder_i2s_dai_ops = { .startup = aiu_encoder_i2s_startup, .shutdown = aiu_encoder_i2s_shutdown, }; -