Hi Laurent,

> From: Laurent Pinchart <[email protected]>
> Sent: 02 August 2019 09:34
> Subject: Re: [PATCH/RFC 12/12] arm64: dts: renesas: Add EK874 board with 
> idk-2121wr display support
> 
> Hi Fabrizio,
> 
> Thank you for the patch.
> 
> On Fri, Aug 02, 2019 at 08:34:09AM +0100, Fabrizio Castro wrote:
> > The EK874 is advertised as compatible with panel IDK-2121WR from
> > Advantech, however the panel isn't sold alongside the board.
> > A new dts, adding everything that's required to get the panel to
> > to work with the EK874, is the most convenient way to support the
> > EK874 when it's connected to the IDK-2121WR.
> >
> > Signed-off-by: Fabrizio Castro <[email protected]>
> > ---
> >  arch/arm64/boot/dts/renesas/Makefile               |   3 +-
> >  .../boot/dts/renesas/r8a774c0-ek874-idk-2121wr.dts | 112 
> > +++++++++++++++++++++
> >  2 files changed, 114 insertions(+), 1 deletion(-)
> >  create mode 100644 
> > arch/arm64/boot/dts/renesas/r8a774c0-ek874-idk-2121wr.dts
> >
> > diff --git a/arch/arm64/boot/dts/renesas/Makefile 
> > b/arch/arm64/boot/dts/renesas/Makefile
> > index 42b74c2..ce48478 100644
> > --- a/arch/arm64/boot/dts/renesas/Makefile
> > +++ b/arch/arm64/boot/dts/renesas/Makefile
> > @@ -1,7 +1,8 @@
> >  # SPDX-License-Identifier: GPL-2.0
> >  dtb-$(CONFIG_ARCH_R8A774A1) += r8a774a1-hihope-rzg2m.dtb
> >  dtb-$(CONFIG_ARCH_R8A774A1) += r8a774a1-hihope-rzg2m-ex.dtb
> > -dtb-$(CONFIG_ARCH_R8A774C0) += r8a774c0-cat874.dtb r8a774c0-ek874.dtb
> > +dtb-$(CONFIG_ARCH_R8A774C0) += r8a774c0-cat874.dtb r8a774c0-ek874.dtb \
> > +                          r8a774c0-ek874-idk-2121wr.dtb
> >  dtb-$(CONFIG_ARCH_R8A7795) += r8a7795-salvator-x.dtb r8a7795-h3ulcb.dtb
> >  dtb-$(CONFIG_ARCH_R8A7795) += r8a7795-h3ulcb-kf.dtb
> >  dtb-$(CONFIG_ARCH_R8A7795) += r8a7795-salvator-xs.dtb
> > diff --git a/arch/arm64/boot/dts/renesas/r8a774c0-ek874-idk-2121wr.dts 
> > b/arch/arm64/boot/dts/renesas/r8a774c0-ek874-idk-
> 2121wr.dts
> > new file mode 100644
> > index 0000000..d989998
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/renesas/r8a774c0-ek874-idk-2121wr.dts
> > @@ -0,0 +1,112 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Device Tree Source for the Silicon Linux RZ/G2E evaluation kit (EK874),
> > + * connected to an Advantech IDK-2121WR 21.5" LVDS panel
> > + *
> > + * Copyright (C) 2019 Renesas Electronics Corp.
> > + */
> > +
> > +#include "r8a774c0-ek874.dts"
> > +
> > +/ {
> > +   backlight: backlight {
> > +           compatible = "pwm-backlight";
> > +           pwms = <&pwm5 0 50000>;
> > +
> > +           brightness-levels = <0 4 8 16 32 64 128 255>;
> > +           default-brightness-level = <6>;
> > +
> > +           power-supply = <&reg_12p0v>;
> > +           enable-gpios = <&gpio6 12 GPIO_ACTIVE_HIGH>;
> > +   };
> > +
> > +   panel-lvds {
> > +           compatible = "advantech,idk-2121wr", "panel-lvds";
> > +
> > +           width-mm = <476>;
> > +           height-mm = <268>;
> > +
> > +           data-mapping = "vesa-24";
> > +
> > +           panel-timing {
> > +                   clock-frequency = <148500000>;
> > +                   hactive = <1920>;
> > +                   vactive = <1080>;
> > +                   hsync-len = <44>;
> > +                   hfront-porch = <88>;
> > +                   hback-porch = <148>;
> > +                   vfront-porch = <4>;
> > +                   vback-porch = <36>;
> > +                   vsync-len = <5>;
> > +           };
> > +
> > +           ports {
> > +                   #address-cells = <1>;
> > +                   #size-cells = <0>;
> > +
> > +                   port@0 {
> > +                           reg = <0>;
> > +                           lvds0_panel_in: endpoint {
> > +                                   remote-endpoint = <&lvds0_out>;
> > +                           };
> > +                   };
> > +
> > +                   port@1 {
> > +                           reg = <1>;
> > +                           lvds1_panel_in: endpoint {
> > +                                   remote-endpoint = <&lvds1_out>;
> > +                           };
> > +                   };
> > +           };
> > +   };
> > +};
> > +
> > +&gpio0 {
> > +   lvds-connector-en-gpio{
> > +           gpio-hog;
> > +           gpios = <17 GPIO_ACTIVE_HIGH>;
> > +           output-low;
> > +           line-name = "lvds-connector-en-gpio";
> > +   };
> 
> Any chance to specify this as the panel's enable signal in the panel DT
> node ?

I am not too sure, as this is not exactly an enable signal. When GP0_17 is low
then LVDS[01] are connected to the LVDS connector, when GP0_17 is high
then LVDS[01] are connected to the LT8918L.
Perhaps we should leave this fixed to low to avoid confusion?

Thanks,
Fab

> 
> > +};
> > +
> > +&lvds0 {
> > +   renesas,swap-data;
> 
> Let's discuss this property in reply to the DT bindings patch.
> 
> > +
> > +   ports {
> > +           port@1 {
> > +                   lvds0_out: endpoint {
> > +                           remote-endpoint = <&lvds0_panel_in>;
> > +                   };
> > +           };
> > +   };
> > +};
> > +
> > +&lvds1 {
> > +   status = "okay";
> > +
> > +   clocks = <&cpg CPG_MOD 727>, <&x13_clk>, <&extal_clk>;
> > +   clock-names = "fck", "dclkin.0", "extal";
> > +
> > +   ports {
> > +           port@1 {
> > +                   lvds1_out: endpoint {
> > +                           remote-endpoint = <&lvds1_panel_in>;
> > +                   };
> > +           };
> > +   };
> > +};
> > +
> > +&pfc {
> > +   pwm5_pins: pwm5 {
> > +           groups = "pwm5_a";
> > +           function = "pwm5";
> > +   };
> > +};
> > +
> > +&pwm5 {
> > +   pinctrl-0 = <&pwm5_pins>;
> > +   pinctrl-names = "default";
> > +
> > +   status = "okay";
> > +};
> 
> I haven't reviewed pinouts in detail, but the patch otherwise looks sane
> to me. Another candidate for DT overlays though ;-)
> 
> --
> Regards,
> 
> Laurent Pinchart

Reply via email to