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| author | Maxime Ripard <maxime.ripard@free-electrons.com> | 2017-11-09 12:40:46 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2017-11-09 14:41:51 +0300 |
| commit | e7b8a6d3efa8316dfe786e9cd559c62e9152337c (patch) | |
| tree | db48e23875547a04e805680d91e4b2b0d219a3ab /sound | |
| parent | 18c1bf35c1c09bca05cf70bc984a4764e0b0372b (diff) | |
| download | linux-e7b8a6d3efa8316dfe786e9cd559c62e9152337c.tar.xz | |
ASoC: sun8i-codec: Add a comment on the LRCK inversion
The current code might be a bit intriguing without having experienced the
issue before, and might come up as a mistake.
Make explicit what's going on by adding a comment.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/soc/sunxi/sun8i-codec.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/sound/soc/sunxi/sun8i-codec.c b/sound/soc/sunxi/sun8i-codec.c index c2ceca485d6a..b3329692e3dc 100644 --- a/sound/soc/sunxi/sun8i-codec.c +++ b/sound/soc/sunxi/sun8i-codec.c @@ -197,6 +197,17 @@ static int sun8i_set_fmt(struct snd_soc_dai *dai, unsigned int fmt) regmap_update_bits(scodec->regmap, SUN8I_AIF1CLK_CTRL, BIT(SUN8I_AIF1CLK_CTRL_AIF1_BCLK_INV), value << SUN8I_AIF1CLK_CTRL_AIF1_BCLK_INV); + + /* + * It appears that the DAI and the codec don't share the same + * polarity for the LRCK signal when they mean 'normal' and + * 'inverted' in the datasheet. + * + * Since the DAI here is our regular i2s driver that have been + * tested with way more codecs than just this one, it means + * that the codec probably gets it backward, and we have to + * invert the value here. + */ regmap_update_bits(scodec->regmap, SUN8I_AIF1CLK_CTRL, BIT(SUN8I_AIF1CLK_CTRL_AIF1_LRCK_INV), !value << SUN8I_AIF1CLK_CTRL_AIF1_LRCK_INV); |