RE: [PATCH 3/3] ASoC: codec: tlv3204: Moving GPIO reset and add ADC reset

["Sit, Michael Wei Hong" <michael.wei.hong.sit@intel.com>]

> -----Original Message-----
> From: Sit, Michael Wei Hong
> Sent: Monday, 3 August, 2020 9:54 AM
> To: Dan Murphy <dmurphy@ti.com>
> Cc: Mark Brown <broonie@kernel.org>; alsa-devel@alsa-
> project.org; tiwai@suse.com; pierre-louis.bossart@linux.intel.com;
> Rojewski, Cezary <cezary.rojewski@intel.com>; Shevchenko, Andriy
> <andriy.shevchenko@intel.com>; liam.r.girdwood@linux.intel.com;
> Sia, Jee Heng <jee.heng.sia@intel.com>; a-estrada@ti.com;
> zakkaye@ti.com
> Subject: RE: [PATCH 3/3] ASoC: codec: tlv3204: Moving GPIO reset
> and add ADC reset
> >
> > On 7/29/20 2:32 AM, Michael Sit Wei Hong wrote:
> > > Moving GPIO reset to a later stage and before clock registration
> to
> > > ensure that the host system and codec clocks are in sync. If the
> > > host register clock values prior to gpio reset, the last configured
> > > codec clock is registered to the host. The codec then gets gpio
> > > resetted setting the codec clocks to their default value, causing a
> mismatch.
> > > Host system will skip clock setting thinking the codec clocks are
> > > already at the requested rate.
> > >
> > > ADC reset is added to ensure the next audio capture does not
> have
> > > undesired artifacts. It is probably related to the original code
> > > where the probe function resets the ADC prior to 1st record.
> > >
> > > Signed-off-by: Michael Sit Wei Hong
> <michael.wei.hong.sit@intel.com>
> > > Reviewed-by: Sia Jee Heng <jee.heng.sia@intel.com>
> > > Reviewed-by: Pierre-Louis Bossart
> > > <pierre-louis.bossart@linux.intel.com>
> > > ---
> > >   sound/soc/codecs/tlv320aic32x4.c | 47
> ++++++++++++++++++++++++-
> > -------
> > >   1 file changed, 35 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/sound/soc/codecs/tlv320aic32x4.c
> > > b/sound/soc/codecs/tlv320aic32x4.c
> > > index 5af438a00f95..37e14558d7c0 100644
> > > --- a/sound/soc/codecs/tlv320aic32x4.c
> > > +++ b/sound/soc/codecs/tlv320aic32x4.c
> > > @@ -50,6 +50,28 @@ struct aic32x4_priv {
> > >   	struct device *dev;
> > >   };
> > >
> > > +static int aic32x4_reset_adc(struct snd_soc_dapm_widget *w,
> > > +			     struct snd_kcontrol *kcontrol, int event)
> {
> > > +	struct snd_soc_component *component =
> > snd_soc_dapm_to_component(w->dapm);
> > > +	u32 adc_reg;
> > > +
> > > +	/*
> > > +	 * Workaround: the datasheet does not mention a required
> > programming
> > > +	 * sequence but experiments show the ADC needs to be
> reset
> > after each
> > > +	 * capture to avoid audible artifacts.
> > > +	 */
> > > +	switch (event) {
> > > +	case SND_SOC_DAPM_POST_PMD:
> > > +		adc_reg = snd_soc_component_read32(component,
> > AIC32X4_ADCSETUP);
> >
> > This gives me a build error
> >
> > sound/soc/codecs/tlv320aic32x4.c: In function
> 'aic32x4_reset_adc':
> > sound/soc/codecs/tlv320aic32x4.c:66:13: error: implicit
> declaration of
> > function 'snd_soc_component_read32'; did you mean
> > 'snd_soc_component_read'? [-Werror=implicit-function-
> declaration]
> >     66 |   adc_reg = snd_soc_component_read32(component,
> > AIC32X4_ADCSETUP);
> >        |             ^~~~~~~~~~~~~~~~~~~~~~~~
> >        |             snd_soc_component_read
> >
> > Also you should check the return to make sure it is valid.
> >
> > Dan
> >
> 
> Hi Dan,
> 
> This code patch is created based on the kernel version 5.8-rc4.
> The register reading and writing are copied from the function
> aic32x4_component_probe.
> May I know the version of the kernel you are applying the patch on?
> 
> Thanks,
> Regards,
> Michael

I have tried to build the kernel with the patches applied on
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git
for-next branch and also on the linux-next branch from
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
Both of them are not throwing errors when I enable the config to build
the codec driver.

Can you double confirm the branch you are building the kernel from?