Re: [PATCH 11/9] move twl4030-gpio to drivers/gpio

David Brownell
2008-09-28T05:16:16Z

On Saturday 27 September 2008, Felipe Balbi wrote:
> On Sat, Sep 27, 2008 at 04:45:20PM -0700, David Brownell wrote:
> > On Saturday 27 September 2008, Felipe Balbi wrote:
> > > We need something like the patch below (I can't find a substitute
> > > to twl4030_set_gpio_edge_ctrl and twl4030_set_gpio_debounce):
> >
> > Something like that, yes. I have other patches queued up though.
> >
> > And meanwhile, your build seems goofed ... fix that first.
>
> Yeah, it only happens when both mmc and twl4030-gpio are built as
> modules. Still sounds weird since we have EXPORT_SYMBOL() for those
> twl-specific crap.

Don't yet build twl4030 as a module. The vmlinux object can't
link against symbols in other objects. ;)

As I noted, the modular option is for build testing; when this
goes to mainline, this code should be able to build on most any
platform. (Not just OMAP; not just ARM.) I don't think any of
the OMAP boards which actually use this code will be able to use
that as a module, though.

When hsmmc.c behaves again, I've got patches to get rid of its
use of those twl-specific symbols. Then that linkage issue
will go away.

> > For debouncing, see this LKML RFC:
> >
> > http://marc.info/?l=linux-kernel&m=122228602206108&w=2
>
> the debouncing mechanism looks really good :-)

Kind of brainless ... except for the observation that
we pretty much need one of those. ;)

> That's true. Didn't got that at first look. We should use something
> like:
>
> return gpio_get_value_cansleep(irq_to_gpio(irq));
>
> right ??

I want to avoid the irq_to_gpio() bit. Eventually the whole
MMC/SD initialization needs reworking ... I doubt Overo will be
the only board using one SD for storage, and an SDIO for WLAN.

> it's good that you've been playing with twl4030-gpio. You've written
> gpiolib anyways, so you might better than I do where stuff should go.

Or in some cases: where it's about time to add mechanisms
to gpiolib. ;)

- dave