Re: [PATCH 4/7] ARM: dts: sun7i: Add pinmux settings for LCD0 RGB888 output.

From: Maxime Ripard <maxime.ripard@bootlin.com>
To: Giulio Benetti <giulio.benetti@micronovasrl.com>
Cc: Paul Kocialkowski <contact@paulk.fr>,
	Thierry Reding <thierry.reding@gmail.com>,
	devicetree@vger.kernel.org, David Airlie <airlied@linux.ie>,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	Chen-Yu Tsai <wens@csie.org>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 4/7] ARM: dts: sun7i: Add pinmux settings for LCD0 RGB888 output.
Date: Mon, 26 Mar 2018 13:46:45 +0200	[thread overview]
Message-ID: <20180326114645.lxvw5twhfzwfsswz@flea> (raw)
In-Reply-To: <e3e51afb-bb32-7f2f-877e-b6c74d71ab06@micronovasrl.com>

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On Mon, Mar 26, 2018 at 01:27:05PM +0200, Giulio Benetti wrote:
> Hi,
> 
> Il 26/03/2018 12:01, Maxime Ripard ha scritto:
> > Hi,
> > 
> > On Sun, Mar 25, 2018 at 04:09:13PM +0200, Paul Kocialkowski wrote:
> > > Le mercredi 21 mars 2018 à 21:03 +0100, Giulio Benetti a écrit :
> > > > The A20 supports RGB888 with H/V sync from LCD0. Add a pinmux setting
> > > > for the needed pins.
> > > > 
> > > > Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
> > > > ---
> > > >   arch/arm/boot/dts/sun7i-a20.dtsi | 8 ++++++++
> > > >   1 file changed, 8 insertions(+)
> > > > 
> > > > diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi
> > > > b/arch/arm/boot/dts/sun7i-a20.dtsi
> > > > index efb5607..bfe6728 100644
> > > > --- a/arch/arm/boot/dts/sun7i-a20.dtsi
> > > > +++ b/arch/arm/boot/dts/sun7i-a20.dtsi
> > > > @@ -922,6 +922,14 @@
> > > >   				pins = "PI20", "PI21";
> > > >   				function = "uart7";
> > > >   			};
> > > > +
> > > > +			lcd0_rgb888_pins: lcd0-rgb888-pins {
> > > 
> > > It would be more consistent with other pins definitions to have
> > > underscores in both names and to indicate the index, such as:
> > > lcd0_rgb888_pins: lcd0_rgb888_pins@0 {
> > 
> > Both your suggestions will generate DTC warnings, and we'd like to get
> > rid of them eventually :)
> > 
> > > This way, other set of pins for LCD (PH0-PH27) can be declared as @1
> > > when they are needed in the future.
> > 
> > A better idea would be to call it lcd0-rgb888-pd-pins, and introduce
> > the ph variant when it's done.
> 
> As I know, only PD is muxed with LCD0.
> And PH is for LCD1 only.
> 
> And LCD0 seems to come out only from PD port according to datasheet,
> this is why I didn't put @0 after lcd0-rgb888-pins.
> 
> So I don't think it makes sense to handle pins in the way Paul suggests.
> 
> What do you all think?
y
That seems sensible in this case, yes.

Maxime

-- 
Maxime Ripard, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com

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