Am Dienstag, 23. Februar 2016, 08:50:04 schrieb Pierre-Louis Bossart:
> On 2/22/16 7:26 PM, Sugar Zhang wrote:
> > enable/disable master clock when codec is active or not.
> >
> > Signed-off-by: Sugar Zhang <sugar.zh...@rock-chips.com>
> > ---
> >
> > Documentation/devicetree/bindings/sound/rt5640.txt | 3 +++
> > sound/soc/codecs/rt5640.c | 31
> > ++++++++++++++++++++++ sound/soc/codecs/rt5640.h
> > | 2 ++
> > 3 files changed, 36 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/sound/rt5640.txt
> > b/Documentation/devicetree/bindings/sound/rt5640.txt index
> > 9e62f6e..57fe646 100644
> > --- a/Documentation/devicetree/bindings/sound/rt5640.txt
> > +++ b/Documentation/devicetree/bindings/sound/rt5640.txt
> >
> > @@ -12,6 +12,9 @@ Required properties:
> > Optional properties:
> > +- clocks: The phandle of the master clock to the CODEC
> > +- clock-names: Should be "mclk"
>
> This patch assumes that the information on mclk comes from DeviceTree.
> The mclk may also be enabled/disabled in the machine driver with an
> explicit transition to use an internal clock when the codec is not used.
> I hope this patch doesn't preclude such usages or there will be a
> conflict with the patches we are about to upstream for Baytrail/cht
> devices.
As you can see, the clock property itself is optional and the clk_get below
acts accordingly of also continuing if the clock is not present.
So it won't affect any users doing it otherwise.
Heiko
> > +
> >
> > - realtek,in1-differential
> > - realtek,in2-differential
> > - realtek,in3-differential
> >
> > diff --git a/sound/soc/codecs/rt5640.c b/sound/soc/codecs/rt5640.c
> > index 11d032c..6cd84fb 100644
> > --- a/sound/soc/codecs/rt5640.c
> > +++ b/sound/soc/codecs/rt5640.c
> > @@ -1949,7 +1949,33 @@ static int rt5640_set_dai_pll(struct snd_soc_dai
> > *dai, int pll_id, int source,>
> > static int rt5640_set_bias_level(struct snd_soc_codec *codec,
> >
> > enum snd_soc_bias_level level)
> >
> > {
> >
> > + struct rt5640_priv *rt5640 = snd_soc_codec_get_drvdata(codec);
> > + int ret;
> > +
> >
> > switch (level) {
> >
> > + case SND_SOC_BIAS_ON:
> > + break;
> > +
> > + case SND_SOC_BIAS_PREPARE:
> > + /*
> > + * SND_SOC_BIAS_PREPARE is called while preparing for a
> > + * transition to ON or away from ON. If current bias_level
> > + * is SND_SOC_BIAS_ON, then it is preparing for a transition
> > + * away from ON. Disable the clock in that case, otherwise
> > + * enable it.
> > + */
> > + if (IS_ERR(rt5640->mclk))
> > + break;
> > +
> > + if (snd_soc_codec_get_bias_level(codec) == SND_SOC_BIAS_ON) {
> > + clk_disable_unprepare(rt5640->mclk);
> > + } else {
> > + ret = clk_prepare_enable(rt5640->mclk);
> > + if (ret)
> > + return ret;
> > + }
> > + break;
> > +
> >
> > case SND_SOC_BIAS_STANDBY:
> > if (SND_SOC_BIAS_OFF == snd_soc_codec_get_bias_level(codec)) {
> >
> > snd_soc_update_bits(codec, RT5640_PWR_ANLG1,
> >
> > @@ -2088,6 +2114,11 @@ static int rt5640_probe(struct snd_soc_codec
> > *codec)>
> > struct snd_soc_dapm_context *dapm = snd_soc_codec_get_dapm(codec);
> > struct rt5640_priv *rt5640 = snd_soc_codec_get_drvdata(codec);
> >
> > + /* Check if MCLK provided */
> > + rt5640->mclk = devm_clk_get(codec->dev, "mclk");
> > + if (PTR_ERR(rt5640->mclk) == -EPROBE_DEFER)
> > + return -EPROBE_DEFER;
> > +
> >
> > rt5640->codec = codec;
> >
> > snd_soc_codec_force_bias_level(codec, SND_SOC_BIAS_OFF);
> >
> > diff --git a/sound/soc/codecs/rt5640.h b/sound/soc/codecs/rt5640.h
> > index 83a7150..1761c3a9 100644
> > --- a/sound/soc/codecs/rt5640.h
> > +++ b/sound/soc/codecs/rt5640.h
> > @@ -12,6 +12,7 @@
> >
> > #ifndef _RT5640_H
> > #define _RT5640_H
> >
> > +#include <linux/clk.h>
> >
> > #include <sound/rt5640.h>
> >
> > /* Info */
> >
> > @@ -2097,6 +2098,7 @@ struct rt5640_priv {
> >
> > struct snd_soc_codec *codec;
> > struct rt5640_platform_data pdata;
> > struct regmap *regmap;
> >
> > + struct clk *mclk;
> >
> > int sysclk;
> > int sysclk_src;
