Re: [PATCH V2 10/15] cpufreq: mediatek: Make sram regulator optional

[Rex-BC Chen <rex-bc.chen@mediatek.com>]

On Fri, 2022-04-08 at 13:32 -0700, Kevin Hilman wrote:
> Rex-BC Chen <rex-bc.chen@mediatek.com> writes:
> 
> > From: Jia-Wei Chang <jia-wei.chang@mediatek.com>
> > 
> > For some MediaTek SoCs, like MT8186, it's possible that the sram
> > regulator
> > is shared between CPU and CCI.
> > 
> > Signed-off-by: Jia-Wei Chang <jia-wei.chang@mediatek.com>
> 
> nit: missing your sign-off.
> 
> > ---
> >  drivers/cpufreq/mediatek-cpufreq.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/cpufreq/mediatek-cpufreq.c
> > b/drivers/cpufreq/mediatek-cpufreq.c
> > index 9e9bce0ff235..8f688d47e64b 100644
> > --- a/drivers/cpufreq/mediatek-cpufreq.c
> > +++ b/drivers/cpufreq/mediatek-cpufreq.c
> > @@ -435,7 +435,7 @@ static int mtk_cpu_dvfs_info_init(struct
> > mtk_cpu_dvfs_info *info, int cpu)
> >  	}
> >  
> >  	/* Both presence and absence of sram regulator are valid cases.
> > */
> > -	info->sram_reg = regulator_get_exclusive(cpu_dev, "sram");
> > +	info->sram_reg = regulator_get_optional(cpu_dev, "sram");
> 
> The changelog says that this regulator may be shared with CCI, so I
> understand it's no longer exclusive.  But here you make it optional,
> which should be explained in the changelog.  If it's not actually
> optional, then it should just be normal "get".
> 
> Kevin

Hello Kevin,

Since cpufreq and cci devfreq might share the same sram regulator in
MediaTek SoC, it is no longer exclusive as you mentioned.

The reason to use regulator_get_optional is we hope regulator framework
can return error for error handling rather than a dummy handler from
regulator_get api.

I will add this to commit message in next version.

Thanks.

BRs,
Rex