Re: [PATCH 3/3] ARM: shmobile: lager: Enable SCIF0 and SCIF1 serial ports in DT

[Simon Horman <horms@verge.net.au>]

On Tue, Oct 29, 2013 at 07:30:05PM +0100, Laurent Pinchart wrote:
> Hi Sergei,
> 
> On Tuesday 29 October 2013 22:09:34 Sergei Shtylyov wrote:
> > On 29-10-2013 19:23, Laurent Pinchart wrote:
> > > SCIF0 and SCIF1 are used as debug serial ports. Enable them and
> > > configure pinmuxing appropriately. We can now remove the clkdev
> > > registration hack for SCIF devices from the Lager reference board file.
> > > 
> > > Signed-off-by: Laurent Pinchart
> > > <laurent.pinchart+renesas@ideasonboard.com>
> > > ---
> > > 
> > >   arch/arm/boot/dts/r8a7790-lager.dts            | 24 ++++++++++++++++----
> > >   arch/arm/mach-shmobile/board-lager-reference.c | 18 ++----------------
> > >   2 files changed, 22 insertions(+), 20 deletions(-)
> > > 
> > > diff --git a/arch/arm/boot/dts/r8a7790-lager.dts
> > > b/arch/arm/boot/dts/r8a7790-lager.dts index a923ab6..9830c87 100644
> > > --- a/arch/arm/boot/dts/r8a7790-lager.dts
> > > +++ b/arch/arm/boot/dts/r8a7790-lager.dts
> > > @@ -16,8 +16,13 @@
> > >   	model = "Lager";
> > >   	compatible = "renesas,lager", "renesas,r8a7790";
> > > 
> > > +	aliases {
> > > +		serial0 = &scif0;
> > > +		serial1 = &scif1;
> > > +	};
> > > +
> > >   	chosen {
> > > -		bootargs = "console=ttySC6,115200 ignore_loglevel rw
> > > root=/dev/nfs ip=dhcp";
> > > +		bootargs = "console=ttySC0,115200 ignore_loglevel rw
> > > root=/dev/nfs ip=dhcp";
> >
> > Hm... is the rename a by-product of the SCIF device tree enablement?
> 
> I suppose we could keep the same serial port name using serial6 and serial7 in 
> the aliases. However, moving to DT will get rid of all other serial ports, so 
> we would be left with ttySC6 and ttySC7, without ttySC0 to ttySC5. I'm not 
> sure if I like that.
> 
> (CC'ing Simon and Magnus to get their opinion on the subject)

It seems logical to me that if we only have two serial ports initialised
that they should be ttySC0 and ttySC1. Even if that leaves us with the pain
of switching over to use ttySC0 instead of ttySC6 as the console.

> 
> > [...]
> > 
> > > diff --git a/arch/arm/mach-shmobile/board-lager-reference.c
> > > b/arch/arm/mach-shmobile/board-lager-reference.c index bc3d0d2..1f5d6e2
> > > 100644
> > > --- a/arch/arm/mach-shmobile/board-lager-reference.c
> > > +++ b/arch/arm/mach-shmobile/board-lager-reference.c
> > > @@ -36,24 +36,10 @@ static void __init lager_init_time(void)
> > > 
> > >   static void __init lager_add_standard_devices(void)
> > >   {
> > >   	/*
> > > -	 * This is a really crude hack to provide clkdev support to the SCIF
> > > -	 * and CMT devices until they get moved to DT.
> > > +	 * This is a really crude hack to provide clkdev support to the CMT
> > > +	 * CMT device until it gets moved to DT.
> > 
> > Minor nit: "CMT" repeated twice.
> 
> I'll fix that. If no other change is required I won't repost the patch before 
> sending the pull request.
> 
> -- 
> Regards,
> 
> Laurent Pinchart
>