Re: [patch/rfc 2.6.19-rc5] arch-neutral GPIO calls

[Bill Gatliff]

David Brownell wrote:

> On Monday 13 November 2006 11:43 am, Bill Gatliff wrote:
>  
>
> > Maybe we should codify an approach for that now, i.e. add to the 
> > reference implementation some code that hands off out-of-range GPIO 
> > lines to a function in the machine descriptor:
> >
> >
> > +static inline int gpio_direction_input(unsigned gpio)
> > +	{ if (gpio < OMAP_MAX_ARCH_GPIO) return __gpio_set_direction(gpio, 1);
> > +	  else if(mdesc->platform_gpio_set_direction) platform_gpio_set_direction(gpio, 1); }
> >
> >
> > ... conveniently neglecting the way you find mdesc.  :)
> >    
>
> Nah; look at arch/arm/plat-omap/gpio.c and ignore the mess, but observe
> that what you see there is essentially a bunch of "gpio controller"
> classes using the ugly "switch(type)" dispatch scheme instead of the
> prettier "type->op()" dispatch scheme.  All that stuff needs to be
> cleaner, but for now it'd suffice to add a new FPGA typecode.
>  

Agreed.  But if we add to the machine descriptor, then not only do you 
not need to touch arch-omap/gpio.c, but you can take that switch 
statement out, too.  Just one less chunk of code to tweak when a new 
platform is supported.


b.g.

--
Bill Gatliff
bgat@xxxxxxxxxxxxxxx

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