Re: [PATCH] gpiolib: Add gpio_detect, gpio_debounce and gpio_alt_func features to GPIOLIB

[Ben Dooks <ben-linux@fluff.org>]

On Mon, Jun 15, 2009 at 11:02:53AM +0100, Mark Brown wrote:
> On Mon, Jun 15, 2009 at 10:50:23AM +0100, Ben Dooks wrote:
> > On Mon, Jun 15, 2009 at 05:15:02PM +0800, Alek Du wrote:
> 
> > > * gpio_alt_func is to set pin as alternative function or GPIO.
> 
> > gpio_alt_func is feature creep, I don't really belive this is the
> > best place to put it as it will be difficult to actually make this
> > generic for all gpio platforms.
> 
> Since the proposed API just passes a value through to the driver for the
> GPIO chip it looks generic enough - each chip can define whatever set of
> constants it likes.  I'd expect a large proportion of driver specific
> APIs would end up just the same.
> 
> Given the number of manufacturers that don't use a separate term like
> the PXA MFP for the alternative functions of their GPIOs it makes sense
> to have a gpiolib API for this.  Without one you end up having each
> driver needing to add its own API, and since the pins are just referred
> to as GPIOs in the documentation the API will have that in the name and
> look like it ought to be connected with gpiolib.

Yes, however I can see some horrible problems ahead as soon as people
try and then try and standardise the values passed through this. The
GPIO API was meant to be a lightweight way of allowing drivers at
GPIOs, now everyone seems to want to push whatever they feel like in.

-- 
Ben (ben@fluff.org, http://www.fluff.org/)

  'a smiley only costs 4 bytes'