LCD integration with IMX6ULL

[karth_t]

I am trying to integrate an LCD module with IMX6ULL. I am trying to use the lcdif node for the device tree to bring up my LCD. I am not using a build environment like Yocto, instead i am using a standalone Kernel source code building with my tool chain.

I have written my own customized device tree file and i have added the lcdif node under the aips2 tree.

            lcdif: lcdif@21c8000 {
                compatible = "fsl,imx6ul-lcdif", "fsl,imx28-lcdif";
                reg = <0x021c8000 0x4000>;
                interrupts = <GIC_SPI 5 IRQ_TYPE_LEVEL_HIGH>;
                assigned-clocks = <&clks IMX6UL_CLK_LCDIF_PRE_SEL>;
                assigned-clock-parents = <&clks IMX6UL_CLK_PLL5_VIDEO_DIV>;
                clocks = <&clks IMX6UL_CLK_LCDIF_PIX>,
                     <&clks IMX6UL_CLK_LCDIF_APB>,
                     <&clks IMX6UL_CLK_DUMMY>;
                clock-names = "pix", "axi", "disp_axi";
                pinctrl-names = "default";
                pinctrl-0 = <&pinctrl_lcdif_dat
                        &pinctrl_lcdif_ctrl>;
                lcd-supply = <&reg_3v3>;
                display= <&display0>;
                status = "okay";

                display0: display@0 {
                    bits-per-pixel = <16>;
                    bus-width = <24>;

                    display-timings {
                        native-mode = <&timing0>;
                        timing0: timing0 {
                            clock-frequency = <50000000>;
                            hactive = <800>;
                            vactive = <480>;
                            hback-porch = <1>;
                            hfront-porch = <200>;
                            hsync-len = <87>;
                            vback-porch = <29>;
                            vfront-porch = <200>;
                            vsync-len = <3>;
                            hsync-active = <0>;
                            vsync-active = <0>;
                            de-active = <1>;
                            pixelclk-active = <0>;
                        };
                    };
                };
            };
            mxcfb1: fb@0 {
                compatible = "fsl,mxc_sdc_fb";
                disp_dev = "lcd";
                interface_pix_fmt = "RGB24";
                //mode_str ="EA7-WVGA";
                default_bpp = <24>;
                int_clk = <0>;
                late_init = <0>;
                status = "okay";
            };

I have the "MXC Framebuffer support" enabled. But i am stuck with this error during bootup.

[drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[drm] No driver support for vblank timestamp query.
OF: graph: no port node found in /soc/aips-bus@02100000/lcdif@21c8000
mxsfb 21c8000.lcdif: Failed to create outputs

Please let me know what i am doing wrong or if i am missing something important here. I know i am.

Also please feel free to ask for more details, if the above is not enough.

Thanks for your time and support.

EDIT: I almost missed to add one more question. The display timing variables in the device tree is probably wrong and i am assuming that even if they are wrong, i can still manage a /dev/fb0 on my Linux. I understand that i might need to get the variables right to get my LCD to display something right. Am i wrong in assuming something like that ?

[igorpadykov]

Hi karth_t

reason for error may be that you are using "standalone Kernel source code building with my tool chain".

May be recommended to try nxp original linux from source.codeaurora.org/external/imx/linux-imx repository

https://source.codeaurora.org/external/imx/linux-imx/tree/?h=imx_5.4.70_2.3.0

Documentation :

https://www.nxp.com/design/software/embedded-software/i-mx-software/embedded-linux-for-i-mx-applicat...

Issues with other linux sources may be posted on meta-fsl-arm mailing list, so that someone familiar

with it could try to assist you.
https://lists.yoctoproject.org/g/meta-freescale

Best regards
igor