diff options
| author | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2009-04-22 21:03:50 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2009-04-22 21:37:36 +0100 |
| commit | d7d5c5476a12333a33b7a14ebb10eccc729c01cb (patch) | |
| tree | 6b1164624c6598a7c4102baf7c2d18a5cb751af4 /sound/soc/codecs | |
| parent | 4dbfe8097157fde1f8054f48f991ea45833852cd (diff) | |
ASoC: Actively manage the DC servo for WM8903
Save a little extra power by enabling the DC servo offset correction
for the output channels only when the relevant channels are enabled.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Diffstat (limited to 'sound/soc/codecs')
| -rw-r--r-- | sound/soc/codecs/wm8903.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/sound/soc/codecs/wm8903.c b/sound/soc/codecs/wm8903.c index de0a5850720..0bab5c6bd64 100644 --- a/sound/soc/codecs/wm8903.c +++ b/sound/soc/codecs/wm8903.c @@ -392,14 +392,18 @@ static int wm8903_output_event(struct snd_soc_dapm_widget *w, struct snd_soc_codec *codec = w->codec; u16 val; u16 reg; + u16 dcs_reg; + u16 dcs_bit; int shift; switch (w->reg) { case WM8903_POWER_MANAGEMENT_2: reg = WM8903_ANALOGUE_HP_0; + dcs_bit = 0 + w->shift; break; case WM8903_POWER_MANAGEMENT_3: reg = WM8903_ANALOGUE_LINEOUT_0; + dcs_bit = 2 + w->shift; break; default: BUG(); @@ -439,6 +443,11 @@ static int wm8903_output_event(struct snd_soc_dapm_widget *w, val |= (WM8903_OUTPUT_OUT << shift); wm8903_write(codec, reg, val); + /* Enable the DC servo */ + dcs_reg = wm8903_read(codec, WM8903_DC_SERVO_0); + dcs_reg |= dcs_bit; + wm8903_write(codec, WM8903_DC_SERVO_0, dcs_reg); + /* Remove the short */ val |= (WM8903_OUTPUT_SHORT << shift); wm8903_write(codec, reg, val); @@ -451,6 +460,11 @@ static int wm8903_output_event(struct snd_soc_dapm_widget *w, val &= ~(WM8903_OUTPUT_SHORT << shift); wm8903_write(codec, reg, val); + /* Disable the DC servo */ + dcs_reg = wm8903_read(codec, WM8903_DC_SERVO_0); + dcs_reg &= ~dcs_bit; + wm8903_write(codec, WM8903_DC_SERVO_0, dcs_reg); + /* Then disable the intermediate and output stages */ val &= ~((WM8903_OUTPUT_OUT | WM8903_OUTPUT_INT | WM8903_OUTPUT_IN) << shift); |