[PATCH v8 4/9] davinci: McASP configuration for Omapl138-Hawkboard

[Nori, Sekhar]

Hi Sergei,

On Mon, Nov 15, 2010 at 17:46:46, Sergei Shtylyov wrote:
> On 15.11.2010 14:10, Nori, Sekhar wrote:
>
> >> This patch defines Pin Mux configuration for MacASP
> >> used on the Hawkboard-L138 system in order to add Audio support
>
> >> Signed-off-by: Victor Rodriguez<victor.rodriguez at sasken.com>
> >> Tested-by: Rene Gonzalez<renegs.2378 at gmail.com>
>
> >> diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c
> >> index 63916b9..f033a0a 100644
> >> --- a/arch/arm/mach-davinci/da850.c
> >> +++ b/arch/arm/mach-davinci/da850.c
> >> @@ -591,7 +591,7 @@ const short da850_cpgmac_pins[] __initdata = {
> >>   const short da850_mcasp_pins[] __initdata = {
> >>        DA850_AHCLKX, DA850_ACLKX, DA850_AFSX,
> >>        DA850_AHCLKR, DA850_ACLKR, DA850_AFSR, DA850_AMUTE,
> >> -     DA850_AXR_11, DA850_AXR_12,
> >> +     DA850_AXR_11, DA850_AXR_12, DA850_AXR_13, DA850_AXR_14,
>
> > Looks like I missed pointing this out previously, but extending
> > this list to take care of all boards will not be right since
> > (for example) AXR13 and AXR14 pins could be used for different
> > purpose on different boards.
>
>     This is correct as the list in da850.c is a *generic* module's pin list.
> If the board needs less pins (and the pins it does not use for McASP are used
> differently), it should define its own pin list.
>
> > The right way would be to make this a per-board list. Since it
> > is marked __initdata, that wouldn't lead to bloat.
>
>     This patch is correct anyway. Unless DA850 EVM board can't use these pins
> for McASP -- but in this case the corresponding board file needs the specific
> pin list added.

Okay. I guess you are saying we will keep adding pins to the generic list
as long as *all* supported boards don't get a conflict and if we run into
a conflict we will spawn separate list for the affected board.

The only issue I see with this approach is it puts too much burden on the
developer to verify that none of the supported boards break.

Since it is highly unlikely that any board will need all the McASP pins,
the generic list will likely remain unused. It might just be easier to
start using board specific lists right away. This is especially true for
McASP where usage of pins across boards will likely vary widely.

Thanks,
Sekhar