Re: [PATCH v3 1/4] gpiolib: Add "unknown" direction support

[Uwe Kleine-König]

Hello,

On Thu, Feb 17, 2011 at 05:03:16PM -0600, Peter Tyser wrote:
> Previously, gpiolib would unconditionally flag all GPIO pins as inputs,
> regardless of their true state.  This resulted in all GPIO output pins
> initially being incorrectly identified as "input" in the GPIO sysfs.
> 
> Since the direction of GPIOs is not known prior to having their
> direction set, instead set the default direction to "unknown" to prevent
> user confusion.  A pin with an "unknown" direction can not be written or
> read via sysfs; it must first be configured as an input or output before
> it can be used.
> 
> While we're playing with the direction flag in/out defines, rename them to
> a more descriptive FLAG_DIR_* format.
Would it make sense to reset the state to unknown on gpio_free?

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
--
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/