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ASoC: Manage VMID mode for WM8990

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A small additional power saving can be achieved for the WM8990 by
maintaining VMID using a 2*250k divider when in standby mode.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This commit is contained in:
Mark Brown 2008-11-17 17:11:14 +00:00
parent be1b87c70a
commit 2adb9833d1
1 changed files with 11 additions and 0 deletions
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11
sound/soc/codecs/wm8990.c
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@ -1222,8 +1222,14 @@ static int wm8990_set_bias_level(struct snd_soc_codec *codec,
switch (level) { switch (level) {
case SND_SOC_BIAS_ON: case SND_SOC_BIAS_ON:
break; break;
case SND_SOC_BIAS_PREPARE: case SND_SOC_BIAS_PREPARE:
/* VMID=2*50k */
val = wm8990_read_reg_cache(codec, WM8990_POWER_MANAGEMENT_1) &
~WM8990_VMID_MODE_MASK;
wm8990_write(codec, WM8990_POWER_MANAGEMENT_1, val | 0x2);
break; break;
case SND_SOC_BIAS_STANDBY: case SND_SOC_BIAS_STANDBY:
if (codec->bias_level == SND_SOC_BIAS_OFF) { if (codec->bias_level == SND_SOC_BIAS_OFF) {
/* Enable all output discharge bits */ /* Enable all output discharge bits */
@ -1278,6 +1284,11 @@ static int wm8990_set_bias_level(struct snd_soc_codec *codec,
wm8990_write(codec, WM8990_EXT_CTL1, 0xa003); wm8990_write(codec, WM8990_EXT_CTL1, 0xa003);
wm8990_write(codec, WM8990_EXT_ACCESS_ENA, 0); wm8990_write(codec, WM8990_EXT_ACCESS_ENA, 0);
} }
/* VMID=2*250k */
val = wm8990_read_reg_cache(codec, WM8990_POWER_MANAGEMENT_1) &
~WM8990_VMID_MODE_MASK;
wm8990_write(codec, WM8990_POWER_MANAGEMENT_1, val | 0x4);
break; break;
case SND_SOC_BIAS_OFF: case SND_SOC_BIAS_OFF: