[PATCH] PXA: Colibri320: Add M41T00 RTC support

[daniel@caiaq.de (Daniel Mack)]

On Sat, Jul 31, 2010 at 09:33:05AM +0200, Marek Vasut wrote:
> Dne So 31. ?ervence 2010 09:26:03 pieterg napsal(a):
> > On Saturday 31 July 2010 04:30:53 Marek Vasut wrote:
> > > +#if defined(CONFIG_RTC_DRV_DS1307) ||
> > > defined(CONFIG_RTC_DRV_DS1307_MODULE)
> > > +static mfp_cfg_t colibri_pxa320_i2c_pin_config[] __initdata = {
> > > +	GPIO32_I2C_SCL,
> > > +	GPIO33_I2C_SDA,
> > > +};
> > 
> > Should the i2c pins really depend on the DS1307 config?
> > On my board, I use a different rtc. So I do need the I2C pins to be
> > configured, but I don't need the DS1307.

Yes, I think you're right. The I2C pins should only be set up if I2C
support for PXA is in fact enabled. If someone manages to build a kernel
which has support for this driver (which should depend on the I2C core
as its transport layer) but not for PXA I2C, that's an unfortunate
exception.

You could think about something like

  select I2C_PXA if RTC_DRV_DS1307

in the Colibri block of mach-pxa/Kconfig, but that's somewhat overdone
maybe.

> Well I'd like to rework the colibri pxa3xx stuff later, but I'll have to discuss 
> it with Dan. I believe reworking it the same way as pxa270 colibri would be nice 
> (and it'd solve your problem too as you use custom board I think?).

Yes, that'd be nice.

> Actually, there is one thing that puzzles me. Eric/Dan, shall I stick all the 
> MFP configs into one (or two, one for board and once for cpu card) array or keep 
> it split in multiple smaller arrays for each device? I think putting it all in 
> one place would be more readable.

Hmm, GPIOs for peripherals that are assembled on the module itself can
safely be configured unconditionally as it is impossible to use them for
anything else. For GPIOs that are allocted by a specific base board,
things are different though, especially for the the Colibri eval board
with it hundreds of jumpers on it. It's a convenience feature to have
them free for general purpose use just by disabling a certain config
directive.

Daniel