[PATCH v2 13/16] arm64: dts: renesas: r8a77990: Add display output support

[Laurent Pinchart]

Hi Simon,

On Wednesday, 19 September 2018 11:35:07 EEST Simon Horman wrote:
> On Mon, Sep 17, 2018 at 11:59:32AM +0300, Laurent Pinchart wrote:
> > On Monday, 17 September 2018 11:54:04 EEST Laurent Pinchart wrote:
> >> On Monday, 17 September 2018 11:47:15 EEST Laurent Pinchart wrote:
> >>> On Monday, 17 September 2018 11:14:20 EEST Simon Horman wrote:
> >>>> On Mon, Sep 17, 2018 at 09:50:55AM +0200, Simon Horman wrote:
> >>>>> On Fri, Sep 14, 2018 at 12:10:43PM +0300, Laurent Pinchart wrote:
> >>>>>> The R8A77990 (E3) platform has one RGB output and two LVDS
> >>>>>> outputs connected to the DU. Add the DT nodes for the DU, LVDS
> >>>>>> encoders and supporting VSP and FCP.
> >>>>>> 
> >>>>>> Signed-off-by: Laurent Pinchart
> >>>>>> <laurent.pinchart+renesas at ideasonboard.com>
> >>>>>> Tested-by: Jacopo Mondi <jacopo+renesas at jmondi.org>
> >>>>>> ---
> >>>>>> 
> >>>>>>  arch/arm64/boot/dts/renesas/r8a77990.dtsi | 167 ++++++++++++++++++++
> >>>>>>  1 file changed, 167 insertions(+)
> >>>>>> 
> >>>>>> diff --git a/arch/arm64/boot/dts/renesas/r8a77990.dtsi
> >>>>>> b/arch/arm64/boot/dts/renesas/r8a77990.dtsi index
> >>>>>> abb14af76c0e..600074ca3ee5 100644
> >>>>>> --- a/arch/arm64/boot/dts/renesas/r8a77990.dtsi
> >>>>>> +++ b/arch/arm64/boot/dts/renesas/r8a77990.dtsi

[snip]

> >>>>>> +		lvds0: lvds-encoder at feb90000 {
> >>>>>> +			compatible = "renesas,r8a77990-lvds";
> >>>>>> +			reg = <0 0xfeb90000 0 0x20>;
> >>>>>> +			clocks = <&cpg CPG_MOD 727>;
> >>>>>> +			power-domains = <&sysc R8A77990_PD_ALWAYS_ON>;
> >>>>>> +			resets = <&cpg 727>;
> >>>>>> +			status = "disabled";
> >>>>>> +
> >>>>>> +			ports {
> >>>>>> +				#address-cells = <1>;
> >>>>>> +				#size-cells = <0>;
> >>>>>> +
> >>>>>> +				port at 0 {
> >>>>>> +					reg = <0>;
> >>>>>> +					lvds0_in: endpoint {
> >>>>>> +						remote-endpoint = <&du_out_lvds0>;
> >>>>>> +					};
> >>>>>> +				};
> >>>>>> +
> >>>>>> +				port at 1 {
> >>>>>> +					reg = <1>;
> >>>>>> +					lvds0_out: endpoint {
> >>>>>> +					};
> >>>>>> +				};
> >>>>>> +			};
> >>>>>> +		};
> >>>>>> +
> >>>>>> +		lvds1: lvds-encoder at feb90100 {
> >>>>>> +			compatible = "renesas,r8a77990-lvds";
> >>>>>> +			reg = <0 0xfeb90100 0 0x20>;
> >>>>>> +			clocks = <&cpg CPG_MOD 727>;
> >>>>>> +			power-domains = <&sysc R8A77990_PD_ALWAYS_ON>;
> >>>>>> +			resets = <&cpg 726>;
> >>>> 
> >>>> Also, is the missmatch between the index for the clock and reset
> >>>> intentional?
> >>> 
> >>> It is. According to the datasheet, the two LVDS encoders have
> >>> different module stop bits, but share the same reset (lovely hardware
> >>> design, it will be fun to support that in the driver :-S).
> >> 
> >> Sorry, I got it wrong. it's bit 725 that is shared between the two LVDS
> >> encoders, to reset the two LVDS PLLs together. The encoders themselves
> >> still have independent reset bits. I'll fix this.
> > 
> > And of course it's the clock you were commenting on, not the reset. *sigh*
> > 
> > According to the datasheets the two LVDS encoders share one MSTP. Whether
> > that's a mistake in the documentation or not I can't tell yet, as I have
> > only tested LVDS0.
> 
> Could we follow-up with the HW team?
> I'm not opposed to taking the patch with this portion as-is
> but it would be good to clarify this somehow.

I tried setting the clock to MSTP 726, and I then get vblank interrupt 
timeouts. Furthermore I've now tested the LVDS1 output with a display panel, 
and while I still can't get the backlight to work, the panel displays the 
correct image with MSTP 727. I thus conclude that the above is correct.

> >>>>>> +			status = "disabled";
> >>>>>> +
> >>>>>> +			ports {
> >>>>>> +				#address-cells = <1>;
> >>>>>> +				#size-cells = <0>;
> >>>>>> +
> >>>>>> +				port at 0 {
> >>>>>> +					reg = <0>;
> >>>>>> +					lvds1_in: endpoint {
> >>>>>> +						remote-endpoint = <&du_out_lvds1>;
> >>>>>> +					};
> >>>>>> +				};
> >>>>>> +
> >>>>>> +				port at 1 {
> >>>>>> +					reg = <1>;
> >>>>>> +					lvds1_out: endpoint {
> >>>>>> +					};
> >>>>>> +				};
> >>>>>> +			};
> >>>>>> +		};

-- 
Regards,

Laurent Pinchart