From mboxrd@z Thu Jan  1 00:00:00 1970
From: shawnguo@kernel.org (Shawn Guo)
Date: Mon, 15 May 2017 10:21:30 +0800
Subject: [PATCH] ARM: dts: imx28: add gpio-ranges for internal gpio
 controller
In-Reply-To: <20170512080150.uh5qmwu2tctpd6jk@pengutronix.de>
References: <20170508085925.18342-1-u.kleine-koenig@pengutronix.de>
 <20170511075135.GF5833@dragon>
 <20170511080916.gim5pyhj5jarzf4r@pengutronix.de>
 <20170512030536.GC8471@dragon>
 <20170512080150.uh5qmwu2tctpd6jk@pengutronix.de>
Message-ID: <20170515022129.GJ8471@dragon>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Fri, May 12, 2017 at 10:01:50AM +0200, Uwe Kleine-K?nig wrote:
> On Fri, May 12, 2017 at 11:05:38AM +0800, Shawn Guo wrote:
> > I went through the code around requesting a pin, and found that we need
> > to call pinctrl_request_gpio() from gpio driver to get the result you
> > want.  In that case, pin_request() will be called with a valid
> > gpio_range as below.
> > 
> >     pinctrl_request_gpio()
> >         pinmux_request_gpio()
> >             pin_request(..., gpio_range)
> > 
> > Right now, pin_request() is being called with a NULL gpio_range from
> > pinmux_enable_setting().  That gets us the mux_owner rather than
> > gpio_owner for the pin.
> 
> But then again I cannot mux a pin to a different function when the gpio
> is requested, right?

You will need to free the GPIO before muxing it to a different function,
I think.

Shawn