[RFC PATCH 12/13] sound: wm8731: rework power management

[Richard Genoud]

From: Nicolas Ferre <nicolas.ferre at atmel.com>

- preserve crystal oscillator across suspend/resume sequence:
  enabled by default,it should be kept enabled on resume.
- if codec is in active state: set the active bit at resume time.

Signed-off-by: Nicolas Ferre <nicolas.ferre at atmel.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
---
 sound/soc/codecs/wm8731.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sound/soc/codecs/wm8731.c b/sound/soc/codecs/wm8731.c
index 5276062..3cf6b20 100644
--- a/sound/soc/codecs/wm8731.c
+++ b/sound/soc/codecs/wm8731.c
@@ -465,7 +465,9 @@ static int wm8731_set_bias_level(struct snd_soc_codec *codec,
 		snd_soc_write(codec, WM8731_PWR, reg | 0x0040);
 		break;
 	case SND_SOC_BIAS_OFF:
-		snd_soc_write(codec, WM8731_PWR, 0xffff);
+		snd_soc_write(codec, WM8731_ACTIVE, 0x0);
+		/* standby: keep crystal oscillator enabled */
+		snd_soc_write(codec, WM8731_PWR, 0x00df);
 		regulator_bulk_disable(ARRAY_SIZE(wm8731->supplies),
 				       wm8731->supplies);
 		regcache_mark_dirty(wm8731->regmap);
@@ -516,6 +518,8 @@ static int wm8731_suspend(struct snd_soc_codec *codec)
 static int wm8731_resume(struct snd_soc_codec *codec)
 {
 	wm8731_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
+	if (codec->active)
+		snd_soc_write(codec, WM8731_ACTIVE, 0x0001);
 
 	return 0;
 }
-- 
1.7.10.4