Re: [PATCH] drm/bridge: ti-sn65dsi86: Implement the pwm_chip

[Shawn Guo]

Hi Uwe,

On Thu, Dec 10, 2020 at 9:05 PM Uwe Kleine-König
<u.kleine-koenig@xxxxxxxxxxxxxx> wrote:
> > > @@ -111,6 +118,8 @@
> > >
> > >  #define SN_LINK_TRAINING_TRIES             10
> > >
> > > +#define SN_PWM_GPIO                        3
> >
> > So this maps to the GPIO4 described in sn65dsi86 datasheet.  I'm
> > wondering if it's more readable to define the following SHIFT constants
> > (your code), and use GPIO_MUX_GPIO4_SHIFT >> 2 where you need GPIO
> > offset?
> >
> > #define  GPIO_MUX_GPIO1_SHIFT 0
> > #define  GPIO_MUX_GPIO2_SHIFT 2
> > #define  GPIO_MUX_GPIO3_SHIFT 4
> > #define  GPIO_MUX_GPIO4_SHIFT 6
> >
> > If you agree, you may consider to integrate this patch beforehand:
> >
> > https://github.com/shawnguo2/linux/commit/7cde887ffb3b27a36e77a08bee3666d14968b586
>
> My preferred way here would be to add a prefix for the other constants.
> It (IMHO) looks nicer and
>
>         GPIO_INPUT_SHIFT
>
> looks like a quite generic name for a hardware specific definition.

While this looks like a reasonable argument, I also like the naming
choice for these constants in the beginning for that distinction
between registers and bits.  And changing the names the other way
around means there will be a much bigger diffstat, which I would like
to avoid.  I suggest let's just focus on what really matters here -
keep the naming consistent, so that people do not get confused when
they want to add more constants in there.

Shawn

> (Even if up to now there is no other code location using this name.)