[PATCHv4][ 1/4] Input: tsc2007: Add device tree support.

[Lothar Waßmann]

Hi,

> On Tue, Oct 22, 2013 at 11:49:47AM +0200, Lothar Waßmann wrote:
> > Hi,
> > 
> > > On Mon, Oct 21, 2013 at 03:54:24PM +0200, Denis Carikli wrote:
> > > >  
> > > > +	if (ts->of)
> > > > +		return tsc2007_get_pendown_state_dt(ts);
> > > > +
> > > >  	if (!ts->get_pendown_state)
> > > >  		return true;
> > > 
> > > Instead of special casing "if (ts->of)" all over the place why don't you
> > > set up the device structure as:
> > > 
> > > 	if (<configuring_tsc2007_form_dt>)
> > > 		ts->get_pendown_state = tsc2007_get_pendown_state_dt;
> > > 
> > > and be done with it?
> > >
> > I also thought about that, but the existing function does not have any
> > parameters, while the DT version of get_pendown_state() requires to get
> > the GPIO passed to it somehow.
> 
> You can always have tsc2007_get_pendown_state_platform() wrapping the
>
Yes, but how would you pass the GPIO number to the
get_pendown_state_dt() function? Global variables are just ugly.

> call. Or we just go and fix board code.
>
That's IMO a better option, but not easy to achieve without breaking
anything. The in-kernel platforms would be easy to fix, but there may be
external users that still use the old hook, so you can't just remove it
or change its semantics.


Lothar Waßmann
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