[PATCHv2 2.6.40 2/3] ARM:simpad: Cleanup CS3 accessors.

[Jamie Iles]

On Mon, Apr 18, 2011 at 08:02:05PM +0200, Jochen Friedrich wrote:
> Hi Jamie,
> 
> >>I'll have a look at this. Last time I checked, a single virtual address
> >>for a wite-only/read-only register pair was not supported, but this
> >>might have changed.
> >
> >You should just be able to specify a single resource named "dat" and
> >you'll be good to go.
> 
> Not really. The "CS3" register on the simpad device is a 16bit register
> which hat 16 write-only pins and 8 independent read-only pins (no
> direction register, at all). It is implemented using 3 TTL logic
> chips.

Ahh, I misread that bit.

> More information about this strange stuff can be found at:
> http://opensimpad.org/index.php/Wiring#CS3_latch
> 
> I'm not sure if handling such a corner-case in the generic driver makes
> sense.

I think I agree with you - it's more like two gpio_chip's using a single 
register and I would guess that it isn't too common a scenario.

Jamie