From a6cea9655bfa821dbf53c6fffb9b2b99fe77367c Mon Sep 17 00:00:00 2001 From: Peter Ujfalusi Date: Fri, 10 Dec 2010 13:26:31 +0200 Subject: [PATCH] ASoC: tlv320dac33: Power down digital parts, when not needed If the following scenario has been followed: 1. Enable analog bypass amixer sset 'Analog Left Bypass' on amixer sset 'Analog Right Bypass' on 2. Start playback aplay -fdat -d3 /dev/zero After the playback stopped (3 sec), and the soc timeout (5 sec), the digital parts of the codec will remain powered up. This means that the DAI clocks are continue to run, the oscillator remain operational, etc. Use the SND_SOC_DAPM_POST_PMD widget to get notification about the stopped stream, and power down the digital part of the codec. If the analog bypass is enabled, than the codec will remain in BIAS_ON level, and things will work correctly. In case, if the bypass is disabled, than the codec will fall to BIAS_STANDBY than to BIAS_OFF level, as it used to. The digital part of DAC33 is initialized at every stream start (DAPM_PRE:PRE_PMU event), so subsequent streams (within 5 sec) will have working DAI. When the codec is coming out from BIAS_OFF, the full power-up sequence followed by the same DAPM_PRE widget event will power up the digital part. Signed-off-by: Peter Ujfalusi Acked-by: Mark Brown Signed-off-by: Liam Girdwood --- sound/soc/codecs/tlv320dac33.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/sound/soc/codecs/tlv320dac33.c b/sound/soc/codecs/tlv320dac33.c index b3445b362e96..776ac80cc1a8 100644 --- a/sound/soc/codecs/tlv320dac33.c +++ b/sound/soc/codecs/tlv320dac33.c @@ -354,6 +354,21 @@ static inline void dac33_soft_power(struct snd_soc_codec *codec, int power) dac33_write(codec, DAC33_PWR_CTRL, reg); } +static inline void dac33_disable_digital(struct snd_soc_codec *codec) +{ + u8 reg; + + /* Stop the DAI clock */ + reg = dac33_read_reg_cache(codec, DAC33_SER_AUDIOIF_CTRL_B); + reg &= ~DAC33_BCLKON; + dac33_write(codec, DAC33_SER_AUDIOIF_CTRL_B, reg); + + /* Power down the Oscillator, and DACs */ + reg = dac33_read_reg_cache(codec, DAC33_PWR_CTRL); + reg &= ~(DAC33_OSCPDNB | DAC33_DACRPDNB | DAC33_DACLPDNB); + dac33_write(codec, DAC33_PWR_CTRL, reg); +} + static int dac33_hard_power(struct snd_soc_codec *codec, int power) { struct tlv320dac33_priv *dac33 = snd_soc_codec_get_drvdata(codec); @@ -402,7 +417,7 @@ exit: return ret; } -static int playback_event(struct snd_soc_dapm_widget *w, +static int dac33_playback_event(struct snd_soc_dapm_widget *w, struct snd_kcontrol *kcontrol, int event) { struct tlv320dac33_priv *dac33 = snd_soc_codec_get_drvdata(w->codec); @@ -414,6 +429,9 @@ static int playback_event(struct snd_soc_dapm_widget *w, dac33_prepare_chip(dac33->substream); } break; + case SND_SOC_DAPM_POST_PMD: + dac33_disable_digital(w->codec); + break; } return 0; } @@ -609,7 +627,8 @@ static const struct snd_soc_dapm_widget dac33_dapm_widgets[] = { SND_SOC_DAPM_SUPPLY("Right DAC Power", DAC33_RDAC_PWR_CTRL, 2, 0, NULL, 0), - SND_SOC_DAPM_PRE("Prepare Playback", playback_event), + SND_SOC_DAPM_PRE("Pre Playback", dac33_playback_event), + SND_SOC_DAPM_POST("Post Playback", dac33_playback_event), }; static const struct snd_soc_dapm_route audio_map[] = { -- 2.20.1