Re: [PATCHv3 0/7] gpio: extend basic_mmio_gpio for differentcontrollers

From: Jamie Iles
Date: Wed May 04 2011 - 10:38:09 EST


On Wed, May 04, 2011 at 03:31:31PM +0400, Anton Vorontsov wrote:
> On Wed, May 04, 2011 at 12:09:39PM +0100, Jamie Iles wrote:
> > On Wed, May 04, 2011 at 02:34:15AM +0400, Anton Vorontsov wrote:
> > > On Tue, May 03, 2011 at 11:04:08PM +0100, Jamie Iles wrote:
> > > [...]
> > > > The advantage that Grant's proposal has though is that the user can
> > > > override the gpio_chip callbacks. When I tried porting over some
> > > > existing ARM platforms, one of the blocking issues was that lots of
> > > > platforms had some annoying small detail that was slightly different
> > > > (such as doing muxing in the _get() callback or needing a to_irq
> > > > callback).
> > > >
> > > > If we make bgpio_chip public and return that from bgpio_probe
> > > > unregistered then the calling code can override some of the methods then
> > > > register the gpio_chip.
> > >
> > > Oh, that makes sense, right.
> >
> > I've just given this a try and it largely works, but it's probably
> > better if we allow bgpio_chip to be embedded in other structures. For
> > example, the langwell driver has a gpio_to_irq callback that we would
> > need to get the IRQ base for the bank. We could add a void *priv member
> > to bgpio_chip but that doesn't feel quite right.
> >
> > So,
> > int bgpio_init(struct bgpio_chip *bgc, struct device *dev,
> > unsigned long sz, void __iomem *dat, ...)
> >
> > rather than a probe() that returns the bgpio_chip?
>
> Sounds good to me.

OK, so here's what I've got so far (patches attached). I've updated the
basic_mmio_gpio library with your initial lkml patch and updated it to
allow bgpio_chip to be embedded in another structure. I've also
attempted to convert over the bt8xx and langwell drivers but they're a
little rough around the edges in places (and untested as I don't have
the hardware).

Jamie