[RFC/RFT 1/2] gpio/basic_mmio: add support for enable register

[Nori, Sekhar]

Hi Ryan,

On Tue, Jul 05, 2011 at 11:45:44, Ryan Mallon wrote:
> On 05/07/11 15:10, Sekhar Nori wrote:
> > Some GPIO controllers have an enable register
> > which needs to be written to before a GPIO
> > can be used.
> >
> > Add support for enabling the GPIO. At this
> > time inverted logic for enabling the GPIO
> > is not supported. This can be done by adding
> > a disable register as and when a controller
> > with this comes along.
> >
> > Signed-off-by: Sekhar Nori<nsekhar at ti.com>
> > ---
> >
> <snip>
> 
> > static int bgpio_setup_io(struct bgpio_chip *bgc,
> >   			  void __iomem *dat,
> > @@ -369,6 +401,7 @@ int __devinit bgpio_init(struct bgpio_chip *bgc,
> >   			 void __iomem *clr,
> >   			 void __iomem *dirout,
> >   			 void __iomem *dirin,
> > +			 void __iomem *en,
> >   			 bool big_endian)
> 
> The arguments to this function are getting a bit unwieldy :-). Maybe we 
> need to introduce something like:
> 
> struct bgpio_chip_info {
>      struct device *dev;
>      unsigned long sz;
>      void __iomem *dat;
>      void __iomem *set;
>      void __iomem *clr;
>      void __iomem *dirout;
>      void __iomem *dirin;
>      void __iomem *en;
>      bool big_endian;
> };
> 
> and pass that to bgpio_init instead. It would have the added benefits of 
> making the drivers more readable and that bgpio_chip_info structs in the 
> drivers can probably be marked __initdata also.
> 
> Since you are already having to touch all of the call sites for 
> bgpio_init this could be done as a separate patch along with this series.

Agreed. I can do this if Grant too thinks this is a
pre-requisite to adding new functionality.

Thanks,
Sekhar