Re: [PATCH] ARM: shmobile: r8a7790: switch from scif to scifa

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Simon,

On Tuesday 30 September 2014 13:30:29 Simon Horman wrote:
> On Fri, Sep 19, 2014 at 12:28:28PM +0900, Simon Horman wrote:
> > On Thu, Sep 18, 2014 at 10:57:12AM +0300, Laurent Pinchart wrote:
> >> On Thursday 18 September 2014 08:55:43 Simon Horman wrote:
> >>> On Wed, Sep 17, 2014 at 05:40:07PM +0300, Laurent Pinchart wrote:
> >>>> On Tuesday 16 September 2014 18:10:37 Wolfram Sang wrote:
> >>>>> From: Wolfram Sang <wsa+renesas@sang-engineering.com>
> >>>>> 
> >>>>> SCIF and SCIFA can be plexed onto the same wires on Lager board.
> >>>>> The datasheet also describes the wires as SCIFA. So, to make use
> >>>>> of the bigger FIFOs switch to SCIFA instead.
> >>>>> 
> >>>>> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> >>>>> ---
> >>>>> 
> >>>>> Currently, I use this patch to check if the DMA RX issue is the
> >>>>> same on SCIF and SCIFA (yes, it is). However, I still think it
> >>>>> makes sense to use the bigger FIFOs. I will check this next week
> >>>>> with Bastian's FIFO patches. Until then, I send this as RFC to
> >>>>> collect opinions speaking for/against this change.
> >>>> 
> >>>> I have nothing against this change, but I believe the aliases should
> >>>> now be serial0 and serial1 to match the legacy code (OK, that's a
> >>>> lame excuse, we all know that I just want to change the aliases
> >>>> ;-)).
> >>> 
> >>> Thanks Laurent, I think its probably time we had that conversation
> >>> again. But I think that change can be done (or not ^) separately to
> >>> this change.
> >> 
> >> It could, but I believe it would make sense to do both in one patch,
> >> otherwise there will be a console serial port device mismatch between
> >> the legacy and multiplatform cases.
> > 
> > I'm a little confused.
> > Does this patch introduce such a miss-match?
> 
> Hi Laurent,
> 
> I'd like to move this forwards somehow.

This patch switches the Lager board to use SCIFA[01] instead of SCIF[01], 
while keeping the Linux devices named /dev/ttySC[67]. With legacy boot, 
SCIFA[01] are named /dev/ttySC[01]. There would thus be a mismatch in that 
sense, even if this change doesn't prevent using the same Linux serial devices 
on both legacy and DT boot.

I'll let you decide whether this is a problem that should be fixed.

> >>> As it is, I think this patch is just a little too late for v3.18.
> >>> I'll see about queuing it up for v3.19 in the not to distant future.
> >>> 
> >>>>>  arch/arm/boot/dts/r8a7790-lager.dts | 24 ++++++++++++------------
> >>>>>  1 file changed, 12 insertions(+), 12 deletions(-)
> >>>>> 
> >>>>> diff --git a/arch/arm/boot/dts/r8a7790-lager.dts
> >>>>> b/arch/arm/boot/dts/r8a7790-lager.dts index
> >>>>> 84dcafa7179b..782f0aa938b3
> >>>>> 100644
> >>>>> --- a/arch/arm/boot/dts/r8a7790-lager.dts
> >>>>> +++ b/arch/arm/boot/dts/r8a7790-lager.dts
> >>>>> @@ -19,8 +19,8 @@
> >>>>>  	compatible = "renesas,lager", "renesas,r8a7790";
> >>>>>  	
> >>>>>  	aliases {
> >>>>> -		serial6 = &scif0;
> >>>>> -		serial7 = &scif1;
> >>>>> +		serial6 = &scifa0;
> >>>>> +		serial7 = &scifa1;
> >>>>>  	};
> >>>>>  	
> >>>>>  	chosen {
> >>>>> @@ -159,9 +159,9 @@
> >>>>>  		renesas,function = "du";
> >>>>>  	};
> >>>>> 
> >>>>> -	scif0_pins: serial0 {
> >>>>> -		renesas,groups = "scif0_data";
> >>>>> -		renesas,function = "scif0";
> >>>>> +	scifa0_pins: serial0 {
> >>>>> +		renesas,groups = "scifa0_data";
> >>>>> +		renesas,function = "scifa0";
> >>>>>  	};
> >>>>>  	
> >>>>>  	ether_pins: ether {
> >>>>> @@ -174,9 +174,9 @@
> >>>>>  		renesas,function = "intc";
> >>>>>  	};
> >>>>> 
> >>>>> -	scif1_pins: serial1 {
> >>>>> -		renesas,groups = "scif1_data";
> >>>>> -		renesas,function = "scif1";
> >>>>> +	scifa1_pins: serial1 {
> >>>>> +		renesas,groups = "scifa1_data";
> >>>>> +		renesas,function = "scifa1";
> >>>>>  	};
> >>>>>  	
> >>>>>  	sdhi0_pins: sd0 {
> >>>>> @@ -308,15 +308,15 @@
> >>>>>  	};
> >>>>>  };
> >>>>> 
> >>>>> -&scif0 {
> >>>>> -	pinctrl-0 = <&scif0_pins>;
> >>>>> +&scifa0 {
> >>>>> +	pinctrl-0 = <&scifa0_pins>;
> >>>>>  	pinctrl-names = "default";
> >>>>>  	status = "okay";
> >>>>>  };
> >>>>> 
> >>>>> -&scif1 {
> >>>>> -	pinctrl-0 = <&scif1_pins>;
> >>>>> +&scifa1 {
> >>>>> +	pinctrl-0 = <&scifa1_pins>;
> >>>>>  	pinctrl-names = "default";
> >>>>>  	
> >>>>>  	status = "okay";

-- 
Regards,

Laurent Pinchart