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

[Pierre-Louis Bossart]

On 5/1/18 9:31 AM, Agrawal, Akshu wrote:
> 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)
> > ÂÂÂÂÂda7219->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.

Alternatively you could modify clk_get to use device_property instead of 
of_property.

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