From: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
To: Siarhei Siamashka
<siarhei.siamashka-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
devicetree <devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org,
Zoltan HERPAI <wigyori-1V5s5g7wVVk@public.gmane.org>
Subject: Re: [PATCH v2 1/3] ARM: dts: sun4i: Allow to use the PH6 pin for GPIO on pcDuino1/2
Date: Sun, 11 Oct 2015 18:47:55 +0200 [thread overview]
Message-ID: <20151011164755.GP2278@lukather> (raw)
In-Reply-To: <1444388979-12072-2-git-send-email-siarhei.siamashka-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
[-- Attachment #1: Type: text/plain, Size: 1430 bytes --]
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-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Applied, thanks!
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
next prev parent reply other threads:[~2015-10-11 16:47 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-09 11:09 [PATCH v2 0/3] ARM: dts: sun4i: Enable USB DRC and voltage-scaling on pcDuino1/2 Siarhei Siamashka
[not found] ` <1444388979-12072-1-git-send-email-siarhei.siamashka-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-10-09 11:09 ` [PATCH v2 1/3] ARM: dts: sun4i: Allow to use the PH6 pin for GPIO " Siarhei Siamashka
[not found] ` <1444388979-12072-2-git-send-email-siarhei.siamashka-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-10-11 16:47 ` Maxime Ripard [this message]
2015-10-09 11:09 ` [PATCH v2 2/3] ARM: sun4i: dt: Add new LinkSprite pcDuino2 board Siarhei Siamashka
[not found] ` <1444388979-12072-3-git-send-email-siarhei.siamashka-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-10-11 16:51 ` Maxime Ripard
2015-10-09 11:09 ` [PATCH v2 3/3] ARM: dts: sun4i: Enable USB DRC on pcDuino1/2 Siarhei Siamashka
[not found] ` <1444388979-12072-4-git-send-email-siarhei.siamashka-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-10-11 17:06 ` Maxime Ripard
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