From mboxrd@z Thu Jan  1 00:00:00 1970
From: andrew@lunn.ch (Andrew Lunn)
Date: Fri, 20 Feb 2015 15:45:47 +0100
Subject: [PATCH 09/10] ARM: mvebu: add Device Tree files for Armada 39x
 SoC and board
In-Reply-To: <20150220151455.461b97bb@free-electrons.com>
References: <1423238276-9206-1-git-send-email-thomas.petazzoni@free-electrons.com>
 <1423238276-9206-10-git-send-email-thomas.petazzoni@free-electrons.com>
 <20150206172153.GY25985@lunn.ch>
 <20150220151455.461b97bb@free-electrons.com>
Message-ID: <20150220144547.GB13797@lunn.ch>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

> > > +			pinctrl at 18000 {
> > > +				uart0_pins: uart0-pins {
> > > +					marvell,pins = "mpp0", "mpp1";
> > > +					marvell,function = "ua0";
> > > +				};
> > > +
> > > +				uart1_pins: uart1-pins {
> > > +					marvell,pins = "mpp19", "mpp20";
> > > +					marvell,function = "ua1";
> > > +				};
> > 
> > Does it make sense to put there in the .dtsi file? I know there are
> > other choices, but generally board manufacturers tend to follow the
> > reference design.
> 
> I am not really convinced here: there are really many possible pin
> muxing possibilities. Various pins for UART0 and UART1, whether you use
> CTS/RTS or not, etc. I believe this is really the sort of pin mux
> configuration that is best left at the board level.

Hi Thomas

Lets look at this from the perspective of lies, damn lies, and
statistics:

Kirkwood has a default pinmux configuration in kirkwood.dtsi. Two of
the sixty six .dts files overwrite the defaults.

Dove has a default pinmux of uart1, but none for uart0.  None of the
.dts files define a pinmux for uart0 and none overwrite the defaults
for uart1.

Armanda XP has a default pinmux for uart2 and uart2 in armada-xp.dtsi,
but none for uart0 or uart1. None of the .dts files define a pinmux
for uart0 or uart1, and none overwrite the defaults for uart2 or
uart3.

Armada 370 has default pinmux for uart0 and uart1. None of the .dts
files overwrite the defaults.

I'm too lazy to look at 375, 380, and 385.

We have over 80 dts files here with defaults from a .dtsi file, and
only two need anything other than defaults.

	 Andrew