[alsa-devel] [RFC PATCH 6/6] ASoC: sgtl5000: Don't disable regulators in SND_SOC_BIAS_OFF

[Eric Nelson]

Disabling the SGTL5000 through regulators would certainly save
power than simply disabling the reference voltages as described
in the data sheet, but won't properly restore things on resume.

As patch 1 in the series shows, no user of this driver has support
for active regulators yet, so this hasn't shown up.

This patch is much more conservative and simply disables the
reference bias currents.

Signed-off-by: Eric Nelson <eric.nelson at boundarydevices.com>
---
 sound/soc/codecs/sgtl5000.c | 32 +++++---------------------------
 1 file changed, 5 insertions(+), 27 deletions(-)

diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c
index 5f7dd5d..d4d793f 100644
--- a/sound/soc/codecs/sgtl5000.c
+++ b/sound/soc/codecs/sgtl5000.c
@@ -767,36 +767,14 @@ static int sgtl5000_set_bias_level(struct snd_soc_codec *codec,
 	switch (level) {
 	case SND_SOC_BIAS_ON:
 	case SND_SOC_BIAS_PREPARE:
-		break;
 	case SND_SOC_BIAS_STANDBY:
-		if (codec->dapm.bias_level == SND_SOC_BIAS_OFF) {
-			ret = regulator_bulk_enable(
-						sgtl5000->num_supplies,
-						sgtl5000->supplies);
-			if (ret)
-				return ret;
-			udelay(10);
-
-			regcache_cache_only(sgtl5000->regmap, false);
-
-			ret = regcache_sync(sgtl5000->regmap);
-			if (ret != 0) {
-				dev_err(codec->dev,
-					"Failed to restore cache: %d\n", ret);
-
-				regcache_cache_only(sgtl5000->regmap, true);
-				regulator_bulk_disable(sgtl5000->num_supplies,
-						       sgtl5000->supplies);
-
-				return ret;
-			}
-		}
-
+		snd_soc_update_bits(codec, SGTL5000_CHIP_ANA_POWER,
+				    SGTL5000_REFTOP_POWERUP,
+				    SGTL5000_REFTOP_POWERUP);
 		break;
 	case SND_SOC_BIAS_OFF:
-		regcache_cache_only(sgtl5000->regmap, true);
-		regulator_bulk_disable(sgtl5000->num_supplies,
-				       sgtl5000->supplies);
+		snd_soc_update_bits(codec, SGTL5000_CHIP_ANA_POWER,
+				    SGTL5000_REFTOP_POWERUP, 0);
 		break;
 	}
 
-- 
1.9.1