Re: [alsa-devel] [PATCH v2] ASoC: da7219: read fmw property to get mclk for non-dts systems

[Agrawal, Akshu]

On 4/30/2018 9:54 PM, Pierre-Louis Bossart wrote:
> On 4/30/18 4:23 AM, Akshu Agrawal wrote:
> > Non-dts based systems can use ACPI DSDT to pass on the mclk
> > to da7219.
> > This enables da7219 mclk to be linked to system clock.
> > Enable/Disable of the mclk is already handled in the codec so
> > platform drivers don't have to explicitly do handling of mclk.
> >
> > Signed-off-by: Akshu Agrawal <akshu.agrawal@xxxxxxx>
> > ---
> > v2: Fixed kbuild error
> > Â include/sound/da7219.hÂÂÂ | 2 ++
> > Â sound/soc/codecs/da7219.c | 7 ++++++-
> > Â 2 files changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/sound/da7219.h b/include/sound/da7219.h
> > index 1bfcb16..df7ddf4 100644
> > --- a/include/sound/da7219.h
> > +++ b/include/sound/da7219.h
> > @@ -38,6 +38,8 @@ struct da7219_pdata {
> > ÂÂÂÂÂ const char *dai_clks_name;
> > +ÂÂÂ const char *mclk_name;
> > +
> > ÂÂÂÂÂ /* Mic */
> > ÂÂÂÂÂ enum da7219_micbias_voltage micbias_lvl;
> > ÂÂÂÂÂ enum da7219_mic_amp_in_sel mic_amp_in_sel;
> > diff --git a/sound/soc/codecs/da7219.c b/sound/soc/codecs/da7219.c
> > index 980a6a8..aed68a4 100644
> > --- a/sound/soc/codecs/da7219.c
> > +++ b/sound/soc/codecs/da7219.c
> > @@ -1624,6 +1624,8 @@ static struct da7219_pdata 
> > *da7219_fw_to_pdata(struct snd_soc_component *compone
> > ÂÂÂÂÂÂÂÂÂ dev_warn(dev, "Using default clk name: %s\n",
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ pdata->dai_clks_name);
> > +ÂÂÂ device_property_read_string(dev, "dlg,mclk-name", 
> > &pdata->mclk_name);
> > +
> > ÂÂÂÂÂ if (device_property_read_u32(dev, "dlg,micbias-lvl", &of_val32) 
> > >= 0)
> > ÂÂÂÂÂÂÂÂÂ pdata->micbias_lvl = da7219_fw_micbias_lvl(dev, of_val32);
> > ÂÂÂÂÂ else
> > @@ -1905,7 +1907,10 @@ static int da7219_probe(struct 
> > snd_soc_component *component)
> > ÂÂÂÂÂ da7219_handle_pdata(component);
> > ÂÂÂÂÂ /* Check if MCLK provided */
> > -ÂÂÂ da7219->mclk = devm_clk_get(component->dev, "mclk");
> > +ÂÂÂ if (da7219->pdata->mclk_name)
> > +ÂÂÂÂÂÂÂ da7219->mclk = clk_get(NULL, da7219->pdata->mclk_name);
> > +ÂÂÂ if (!da7219->mclk)
> > +ÂÂÂÂÂÂÂ da7219->mclk = devm_clk_get(component->dev, "mclk");
>
> this looks weird, why are you using different clk functions depending on 
> the existence of a _DSD property? Why not just change the name and keep 
> the same flow, e.g something like
>
> if(!da7219->pdata->mclk_name)
>  ÂÂÂÂda7219->pdata->mclk_name = "mclk";
> da7219->mclk = devm_clk_get(component->dev, da7219->pdata->mclk_name);

We can't use devm_clk_get as the value of dev argument has to be NULL, 
which can not be used with devm_clk_get.
System clock which are linked to mclk are registered by a separate ACPI 
device. And this exposing of DSD property is for all those platforms 
which are non-dts based.

> > ÂÂÂÂÂ if (IS_ERR(da7219->mclk)) {
> > ÂÂÂÂÂÂÂÂÂ if (PTR_ERR(da7219->mclk) != -ENOENT) {
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂ ret = PTR_ERR(da7219->mclk);