[PATCH 2/5] ARM: dts: OMAP2+: create a DT header for GPIO
swarren at wwwdotorg.org
Wed May 22 12:03:26 EDT 2013
On 05/22/2013 10:00 AM, Florian Vaussard wrote:
> Hello Stephan, Tony,
> Thank you for your reviews.
> On 05/22/2013 05:34 PM, Tony Lindgren wrote:
>> * Stephen Warren <swarren at wwwdotorg.org> [130522 08:32]:
>>> On 05/22/2013 08:27 AM, Florian Vaussard wrote:
>>>> Define the OMAP_GPIO macro to conveniently use GPIO inside OMAP DT.
>>>> For example:
>>>> gpios = <&gpio6 3 0>; /* GPIO 163 */
>>>> can be replaced by
>>>> gpios = OMAP_GPIO(163, 0);
>>>> diff --git a/include/dt-bindings/gpio/omap-gpio.h
>>>> +#define OMAP_GPIO_0_BANK gpio1
>>>> +#define OMAP_GPIO_1_BANK gpio1
>>>> +#define OMAP_GPIO_2_BANK gpio1
>>>> +#define OMAP_GPIO_3_BANK gpio1
>>> There are a /lot/ of those. Is this really worth it?
> From a board point a view, I consider this macro as being easier to use,
> than having to perform the necessary arithmetic to get the bank + offset
> for each GPIO when converting existing boards or developing new ones.
> But I also agree with you, and I was sad not to find a more elegant
> way. Maybe someone with better preprocessor skills could come up with
> a better solution?
I did a quick bit of searching before, and while cpp is certainly
capable of doing the shifting/masking required to calculate the bank ID
directly, I don't think it's capable of constructing the symbol gpio1 as
opposed to the string "gpio1":-( I'd love to be proven wrong though, but
the torture e.g. cpp "99 bottles of beer on the wall" goes through to
stuff implies it isn't possible.
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