Tegra gpio driver: Need to configure pins in gpio mode/nontristate with gpio-request

[Erik Gilling]

GPIO and pinmuxing are two different things.  The GPIO api
docs explicitly state the gpio_request should take no affect ofther than
marking that GPIO as in use.

-Erik

On Thu, May 5, 2011 at 3:16 AM, Laxman Dewangan <ldewangan at nvidia.com>wrote:

> Hi All,
> When working on gpio driver for tegra, I found that gpio_request() does not
> make the corresponding soc pins to gpio mode. It still keeps the pins in
> SFIO mode.
> So we need to call two extra function along with gpio_request():
> Tegra_gpio_enable() and function for setting the pins in no non-tristate.
>
> Sue to this, the gpio sysfs interface does not work properly from user
> space /sys/class/gpio/.
> To make the pin in gpio mode fom user space, need to have changes in
> kernel.
>
> I think the gpio_request() should make the pins to gpio mode and make ready
> for use.
> Similarly gpio_free() should again put the pin into sfio mode with tristate
> disable.
>
> Please comment if there is any better way..
>
>
> Thanks,
> Laxman
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20110505/859103e5/attachment-0001.html>