[PATCH v2 1/3] ARM: dts: sun4i: Allow to use the PH6 pin for GPIO on pcDuino1/2
Maxime Ripard
maxime.ripard at free-electrons.com
Sun Oct 11 09:47:55 PDT 2015
On Fri, Oct 09, 2015 at 02:09:37PM +0300, Siarhei Siamashka wrote:
> The pcDuino1 board does not use any power switches at all for its
> two USB host ports and the VBUS pins are always connected to 5V.
>
> The pcDuino2 board uses the RT9701GB power switch for its single
> USB host port, but the USB_EN pin (PD2) is pulled up with a 10K
> resistor. So that the USB power is still enabled by default,
> resulting in the same behaviour as pcDuino1 if nobody touches
> the PD2 pin. This minor difference is going to be handled in a
> follow-up patch, introducing a separate dts file for pcDuino2.
>
> The primary reason for this fix is that the current dts file
> unnecessarily meddles with the PH3 and PH6 pins. But the PH6 pin
> is available on the Arduino-compatible expansion header and may
> have a better use for other purposes. This patch fixes the
> problem and now the PH6 pin can be used with the GPIO sysfs
> interface. Tested on a pcDuino2 board with a multimeter:
>
> echo 230 > /sys/class/gpio/export
> echo "out" > /sys/class/gpio/gpio230/direction
> echo 0 > /sys/class/gpio/gpio230/value
> echo 1 > /sys/class/gpio/gpio230/value
>
> USB still works as expected too.
>
> Signed-off-by: Siarhei Siamashka <siarhei.siamashka at gmail.com>
Applied, thanks!
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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