LVDS Framebuffer hummingboard Kernel 4.13

[Dig Kleppe]

Hi

I moved from  3.14 to 4.13. In 3.14 I had a imx framebuffer , needed for my lvds LCD

In the 4.13 kernel menuconfig i cannot find a way to set CONFIG_FB_IMX.

How to enable this?

Dig

 

 

[Igor]

It is possible that there are no drivers for this in a modern kernel yet. This is common for all boards. Check around if there are some patches for or prepare to port this driver. We don't have resources for such task.

[zador.blood.stained]

There is a i.MX6 LVDS driver, but it's a DRM driver (kernel option CONFIG_DRM_IMX_LDB). It may need some DT modifications in order to activate it (hard to say since I don't own any i.MX6 HW)

[Dig Kleppe]

Hi, thanks for the quick reply.

I was digging in the source and found the DRM stuff.  I have compiled this into the kernel. Still no fb. Have to adapt the dtb.

Is nobody using the LVDS on the solo module?

Dig

[zador.blood.stained]

I suggest looking at existing imx6* Device Trees in mainline kernel sources since looks like some devices enable LVDS output.

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit?id=0afe7a34921fc81b53a2d02ef69fb31eceef4c23

 

[Dig Kleppe]

I have trouble getting the driver (imx-ldb)  to load. It is present in the kernel, but there is no sign of it in dmesg. Also no fb.

In my dtb:

    //    ldb: ldb {      The address was missing in the original dtsi , needed?
            ldb: ldb@020e0008 {  
                #address-cells = <1>;
                #size-cells = <0>;
                compatible = "fsl,imx6q-ldb", "fsl,imx53-ldb";      The driver is imx6q   Works for Solo ?
                gpr = <&gpr>;
                status = "okay";

                lvds-channel@0 {
                #address-cells = <1>;
                #size-cells = <0>;
                    reg = <0>;
                    status = "okay";

                    port@0 {
                        reg = <0>;

                        lvds0_mux_0: endpoint {
                            remote-endpoint = <&ipu1_di0_lvds0>;
                        };
                    };

                    port@1 {
                        reg = <1>;

                        lvds0_mux_1: endpoint {
                    //        remote-endpoint = <&ipu1_di1_lvds0>;
                            remote_endpoint = <&panel_in>;
                        };
                    };
                };

                panel { // klp
                    compatible = "mitsubishi,aa121td01", "panel-lvds";

                    width-mm = <261>;
                    height-mm = <163>;

                    data-mapping = "jeida-24";

                    panel-timing {
                        clock-frequency = <60000000>;
                        hactive = <1024>;
                        vactive = <600>;
                        hback-porch = <160>;
                        hfront-porch = <160>;
                        vback-porch = <23>;
                        vfront-porch = <12>;
                        hsync-len = <70>;  // 60
                        vsync-len = <15>;// 10
                        // <1>: high active
                        // <0>: low active
                        hsync-active = <1>;//hsync pulse is active low/high/ignored
                        vsync-active = <1>;//vsync pulse is active low/high/ignored
                        //    de-active = <1>;
                        pixelclk-active = <1>;// active high = drive pixel data on rising edge/sample data on falling edge
                        // active low  = drive pixel data on falling edge/    sample data on rising edge
                    };

                    port {
                        panel_in: endpoint {
                            remote-endpoint = <&lvds_out>;
                        };
                    };
                };

Any idea?

 

 

 

 

 

[zador.blood.stained]

4 minutes ago, Dig Kleppe said:

    //    ldb: ldb {      The address was missing in the original dtsi , needed?
            ldb: ldb@020e0008 {  

No, node name is irrelevant.

 

5 minutes ago, Dig Kleppe said:

                compatible = "fsl,imx6q-ldb", "fsl,imx53-ldb";      The driver is imx6q   Works for Solo ?

I would suggest looking at DT bindings docs: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/devicetree/bindings/display/imx

[Dig Kleppe]

Thanks,

I did, with above result. If the driver would not work for the solo i expect to see a message when the the driver is probed. It seems that no attempt is made to load the driver.