Hi all

I have an Allwinner A64 based device and I wanted to bring the LVDS Display to 
live.
http://linux-sunxi.org/Honeywell_VDP7

Attached is the patch for Jagan Tekis kernel from
https://github.com/amarula/linux-amarula.git
Version: 3fcf0ebf8263377172da3ad0628c67e411a58831

I added the LVDS pins to the sun50i-a64.dtsi:
lcd_lvds_pins: lcd-lvds-pins {
        pins = "PD12", "PD13", "PD14", "PD15", "PD16",
        "PD17", "PD18", "PD19", "PD20", "PD21";
        function = "lvds0";
};

And I used the information from sun8i-a83t-tbs-a711.dts with changed values to 
write my own connection:
+       panel {
+               compatible = "tbs,a711-panel", "panel-lvds";
+               backlight = <&backlight>;
+               power-supply = <&reg_dc1sw>;
+
+               width-mm = <154>;
+               height-mm = <86>;
+               data-mapping = "vesa-24";
+
+/*             reset-gpios = <&pio 3 24 GPIO_ACTIVE_HIGH>;*/ /* RST (PD24) */
+
+               panel-timing {
+                       /* 1024x600 @60Hz */
+                       clock-frequency = <51450000>;
+                       hactive = <1024>;
+                       vactive = <600>;
+                       hsync-len = <8>;
+                       hfront-porch = <156>;
+                       hback-porch = <156>;
+                       vfront-porch = <16>;
+                       vback-porch = <16>;
+                       vsync-len = <6>;
+//                     de-active = <0>;
+//                     hsync-active = <1>;
+//                     vsync-active = <1>;
+               };
+
+               port {
+                       panel_input: endpoint {
+                               remote-endpoint = <&tcon0_out_lcd>;
+                       };
+               };
+       };
And for TCON connection
+&tcon0 {
+       pinctrl-names = "default";
+       pinctrl-0 = <&lcd_lvds_pins>;
+};
+
+&tcon0_out {
+       tcon0_out_lcd: endpoint@0{
+               reg = <0>;
+               remote-endpoint = <&panel_input>;
+       };

I will get a framebuffer device. The backlight is working and I can change the 
brightness. The panal-lvds is used and the clock looks that they will be 
generated in the attached bootlog.
I also added some additional debug outputs to be aware, that the functions are 
called. Looks also fine for me.

I checked the sunxi-lvds source file and compared the lvds register settings 
with the voltage levels on the pins. They are identical and looking fine for 
me. I checked with an Osciloscope the signals but they are statical. No changes 
on them. I also checked the reset line, voltages and so on, they are correct 
that with signal input all should work.

My current thinking is, that there are something wrong with the dts tcon 
connection. I checked also to use reg 1 (MIPI) and not reg 0, but then I will 
get no framebuffer and some dct warnings that the MIPI Display is only 
connected in one direction. 

I'm going deeper and deeper in the dts writing and find a lot. But lvds and 
allwinner devices is not really documented anywhere.
Did someone has an idea what could be wrong?

My next check will be the new 5.1 kernel release.

Best regards
John-Eric

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Attachment: 0120-add-vdp-dts-files.patch
Description: 0120-add-vdp-dts-files.patch

Attachment: boot.log
Description: boot.log

Attachment: 0100-Added-LVDS-information-to-dts.patch
Description: 0100-Added-LVDS-information-to-dts.patch

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