How to configure LVDS in dual channel with kernel 3.14.28

Technical Support
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1

Hello,

I want to configure LVDS in dual channels with kernel 3.14.28 on the Apalis IMX6Q 2GB IT.
With old kernel the cmdline parameters for this screen was :

video=mxcfb0:dev=ldb,1920x1080M@50,if=RGB24 ldb=spl0

Can anyone help me.

Thanks

2

Hi

I will have to change the device tree and adapt the kernel cmdline to contain:
video=mxcfb0:dev=ldb

In the device tree the display interface (node mxcfb1) must be configured for 24 pixel mode, and the LVDS Display Bridge (node ldb) must be configured for split-mode, 24bit data-width and the first display-timing must be the one you need.

E.g. something like this:

--- a/arch/arm/boot/dts/imx6qdl-apalis.dtsi
+++ b/arch/arm/boot/dts/imx6qdl-apalis.dtsi
@@ -81,7 +81,7 @@
        mxcfb1: fb@0 {
                compatible = "fsl,mxc_sdc_fb";
                disp_dev = "ldb";
-               interface_pix_fmt = "RGB666";
+               interface_pix_fmt = "RGB24";
                default_bpp = <16>;
                int_clk = <0>;
                late_init = <0>;
@@ -1000,13 +1000,13 @@
 
 &ldb {
        status = "okay";
-//     split-mode;
+       split-mode;
 //     dual-mode;
 
        lvds-channel@0 {
                reg = <0>;
                fsl,data-mapping = "spwg"; /* "jeida"; */
-               fsl,data-width = <18>;
+               fsl,data-width = <24>;
                crtc = "ipu2-di1";
                primary;
                status = "okay";
@@ -1030,7 +1030,6 @@
                                vsync-active = <0>;
                                pixelclk-active = <0>;
                        };
-#endif
                        /* Standard XGA timing */
                        timing_xga: 1024x768 {
                                clock-frequency = <65000000>;
@@ -1060,6 +1059,7 @@
                                vsync-active = <0>;
                                pixelclk-active = <0>;
                        };
+#endif
                        timing_fullhd: 1920x1080 {
                                clock-frequency = <138500000>;
                                hactive = <1920>;
3

Thank you for your answer