Backlight working but LCD screen is not showing anything

[shamiullah]

Hi

I am using custom board based on IMX6UL NXP EVK. I am trying to integrate AFY1024600A0-7.0INTH-R LVDS LCD on custom board. I am using SN65LVDS93B RGB to LVDS bridge. When i connected the LCD to the board, i am able to control the backlight but nothing is coming on the screen. The boot logo (penguin logo) is enabled but it is not coming.

I added the following lines in the device tree for my LCD

-------------------------------------------

&lcdif {
assigned-clocks = <&clks IMX6UL_CLK_LCDIF_PRE_SEL>;
assigned-clock-parents = <&clks IMX6UL_CLK_PLL5_VIDEO_DIV>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_lcdif_dat
&pinctrl_lcdif_ctrl>;
display = <&display0>;
status = "okay";

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

display-timings {
native-mode = <&timing0>;

timing0: timing0 {
clock-frequency = <51000000>;
hactive = <1024>;
vactive = <600>;
hfront-porch = <160>;
hback-porch = <160>;
hsync-len = <0>;
vback-porch = <23>;
vfront-porch = <12>;
vsync-len = <0>;
};

-----------------------------------
   in  imx6ul.dtsi

lcdif: lcdif@21c8000 {
compatible = "fsl,imx6ul-lcdif", "fsl,imx28-lcdif";
reg = <0x021c8000 0x4000>;
interrupts = <GIC_SPI 5 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&clks IMX6UL_CLK_LCDIF_PIX>,
<&clks IMX6UL_CLK_LCDIF_APB>,
<&clks IMX6UL_CLK_DUMMY>;
clock-names = "pix", "axi", "disp_axi";
status = "disabled";
};

the above node is the default support given by NXP for RGB. So i am using same driver.

Please find the logs attached to this issue

Please let me know if any

[igorpadykov]

Hi Shamiullah

for configuration lvds bridge with i.MX6UL one can look at

https://www.digi.com/resources/documentation/digidocs/90001548/reference/bsp/6ul/r_video_6ul.htm
https://github.com/digi-embedded/linux/blob/v5.4/dey-3.0/maint/arch/arm/boot/dts/imx6ul-ccimx6ulsbc....

Best regards
igor

[shamiullah]

Hello igor,

I followed the information which is mentioned in the links but i am facing the same issue.

"fb" nodes are present whether i remove the lcd.  How to confirm whether it is dummy nodes or not?

Thanks & Regards

Shamiullah