Messages in this thread | | | Date | Fri, 18 Feb 2011 09:51:23 +0100 | From | Uwe Kleine-König <> | Subject | Re: [PATCH v3 1/4] gpiolib: Add "unknown" direction support |
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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@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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