ASoC: Manage VMID mode for WM8990
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>
diff --git a/sound/soc/codecs/wm8990.c b/sound/soc/codecs/wm8990.c
index 938e154..2d7b009 100644
--- a/sound/soc/codecs/wm8990.c
+++ b/sound/soc/codecs/wm8990.c
@@ -1222,8 +1222,14 @@
switch (level) {
case SND_SOC_BIAS_ON:
break;
+
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;
+
case SND_SOC_BIAS_STANDBY:
if (codec->bias_level == SND_SOC_BIAS_OFF) {
/* Enable all output discharge bits */
@@ -1278,6 +1284,11 @@
wm8990_write(codec, WM8990_EXT_CTL1, 0xa003);
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;
case SND_SOC_BIAS_OFF: