ASoC: nau8540: PGA short to ground

Change channel PGA input mode selection for better recording quality.
The patch shorts the inputs to ground with 12kOhm differentially
terminated.

Signed-off-by: John Hsu <KCHSU0@nuvoton.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/codecs/nau8540.c b/sound/soc/codecs/nau8540.c
index c10cbffa63149a8b05d90bd3e31b0fd562da8c31..8246486a588dc6f255433d48c5a5903a1ddf04fa 100644 (file)
--- a/sound/soc/codecs/nau8540.c
+++ b/sound/soc/codecs/nau8540.c
@@ -730,6 +730,13 @@ static void nau8540_init_regs(struct nau8540 *nau8540)
        regmap_update_bits(regmap, NAU8540_REG_ADC_SAMPLE_RATE,
                NAU8540_CH_SYNC | NAU8540_ADC_OSR_MASK,
                NAU8540_CH_SYNC | NAU8540_ADC_OSR_64);
+       /* PGA input mode selection */
+       regmap_update_bits(regmap, NAU8540_REG_FEPGA1,
+               NAU8540_FEPGA1_MODCH2_SHT | NAU8540_FEPGA1_MODCH1_SHT,
+               NAU8540_FEPGA1_MODCH2_SHT | NAU8540_FEPGA1_MODCH1_SHT);
+       regmap_update_bits(regmap, NAU8540_REG_FEPGA2,
+               NAU8540_FEPGA2_MODCH4_SHT | NAU8540_FEPGA2_MODCH3_SHT,
+               NAU8540_FEPGA2_MODCH4_SHT | NAU8540_FEPGA2_MODCH3_SHT);
 }
 
 static int __maybe_unused nau8540_suspend(struct snd_soc_codec *codec)

diff --git a/sound/soc/codecs/nau8540.h b/sound/soc/codecs/nau8540.h
index 14339f9bb01ac3526e340a2173771c5496f37438..7083d4821ce4c9cb364a21b0212e4b0727112a87 100644 (file)
--- a/sound/soc/codecs/nau8540.h
+++ b/sound/soc/codecs/nau8540.h
@@ -184,6 +184,18 @@
 #define NAU8540_PRECHARGE_DIS          (0x1 << 13)
 #define NAU8540_GLOBAL_BIAS_EN (0x1 << 12)
 
+/* FEPGA1 (0x69) */
+#define NAU8540_FEPGA1_MODCH2_SHT_SFT  7
+#define NAU8540_FEPGA1_MODCH2_SHT      (0x1 << NAU8540_FEPGA1_MODCH2_SHT_SFT)
+#define NAU8540_FEPGA1_MODCH1_SHT_SFT  3
+#define NAU8540_FEPGA1_MODCH1_SHT      (0x1 << NAU8540_FEPGA1_MODCH1_SHT_SFT)
+
+/* FEPGA2 (0x6A) */
+#define NAU8540_FEPGA2_MODCH4_SHT_SFT  7
+#define NAU8540_FEPGA2_MODCH4_SHT      (0x1 << NAU8540_FEPGA2_MODCH4_SHT_SFT)
+#define NAU8540_FEPGA2_MODCH3_SHT_SFT  3
+#define NAU8540_FEPGA2_MODCH3_SHT      (0x1 << NAU8540_FEPGA2_MODCH3_SHT_SFT)
+
 
 /* System Clock Source */
 enum {