Re: [V7, 2/2] media: i2c: dw9768: Add DW9768 VCM driver

Sakari Ailus
2020-06-10T12:58:39Z

Hi Andy, Dongchun,

On Tue, Jun 09, 2020 at 02:14:28PM +0300, Andy Shevchenko wrote:
> On Tue, Jun 09, 2020 at 11:45:41AM +0800, Dongchun Zhu wrote:
> > On Mon, 2020-06-08 at 16:27 +0300, Andy Shevchenko wrote:
> > > On Sat, Jun 06, 2020 at 02:19:18PM +0800, Dongchun Zhu wrote:
> > > > On Fri, 2020-06-05 at 15:46 +0300, Andy Shevchenko wrote:
> > > > > On Fri, Jun 05, 2020 at 06:54:12PM +0800, Dongchun Zhu wrote:
>
> ...
>
> > > > > > +#define DW9768_AAC_TIME_DEFAULT 0x20
> > > > >
> > > > > Hex? Why not decimal?
> > > > >
> > > >
> > > > There is one optional property 'dongwoon,aac-timing' defined in DT.
> > > > I don't know whether you have noticed that.
> > > >
> > > > 'DW9768_AAC_TIME_DEFAULT' is the value set to AACT[5:0] register.
> > > > I thought the Hex unit should be proper as it is directly written to the
> > > > Hex register.
> > >
> > > I see. I would rather put it like (BIT(6) / 2) to show explicitly that we
> > > choose half of the resolution.
> > >
> >
> > I knew your idea.
> > '(BIT(6) / 2)' may somewhat show the meaning of 'median of the total
> > range of AACT[5:0]'.
> >
> > But this value is still very obscure relative to '0x20'.
> > As I thought that simple is the best, especially for kernel upstream
> > patch.
>
> Okay, let's wait for maintainers to speak up.

The value 0x20 is the device default, I don't see it having any other
special significance. So I'm totally fine with 0x20.

--
Kind regards,

Sakari Ailus