RE: [PATCH] gpio: add flags to export GPIOs when requesting

[Stephen Warren]

Denis Kuzmenko wrote at Tuesday, November 15, 2011 4:05 PM:
> Hi Wolfram,
> On 11/16/2011 12:44 AM, Wolfram Sang wrote:
> > Introduce new flags to automatically export GPIOs when using the convenience
> > functions gpio_request_one() or gpio_request_array(). This eases support for
> > custom boards where lots of GPIOs need to be exported for customer
> > applications.
> 
> Adding GPIO maintainer Grant Likely to CC.
> 
> > +#define GPIOF_EXPORT		(1 << 2)
> > +#define GPIOF_EXPORT_CHANGEABLE	(1 << 3)
> > +#define GPIOF_EXPORT_DIR_FIXED	(GPIOF_EXPORT)
> > +#define GPIOF_EXPORT_DIR_CHANGEABLE (GPIOF_EXPORT | GPIOF_EXPORT_CHANGEABLE)
> 
> Maybe, it's better to write like this:
> 
> #define GPIOF_EXPORT			(1 << 2)
> #define GPIOF_EXPORT_DIR_CHANGEABLE	(3 << 2)

Then you won't have a single flag to check if the dir is changeable.

Personally, I'd go for the two single-bit flags, and force boards to OR
them together if they want the GPIO exported and with a changeable
direction; just get rid of the two _DIR_ flags. That said, Wolfram's
patch seems to follow the conventions already in the file.

Dong Aisheng posted patch "gpio: introduce gpio_export_array to ease
export for gpio arrays". Which should we pick; it doesn't seem like we
need both mechanisms.

-- 
nvpublic

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/