No Display on LVDS

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No Display on LVDS

983 Views
VinithNama
Contributor III

Hi,

     I'm working on IM8M MINI EVK Linux platform, we are working on integration of panasys LVDS display and we are using SN65DSI83 as an bridge converter.

I 'have applied below patch at the directory kernel-sourcr/.../git/drivers/gpu/drm/bridge.

and i have updated in my device tree file build/tmp/work-shared/imx8qmevk/kernel-source/arch/arm64/boot/dts/freescale/imx8mm-evk.dts as below

&lcdif{
 max-res = <1280>, <1024>;
 status = "okay";
};
 
&mipi_dsi {
       status = "okay";
 
        port@1 {
                dsim_to_sn65dsi8: endpoint {
                        remote-endpoint = <&sn65dsi83_in>;
                };
       };
};
 
&i2c2 {
    clock-frequency = <100000>;
    pinctrl-names = "default";
    status = "okay";
 
    lvds_bridge: sn65dsi83@2c {
        compatible = "ti,sn65dsi83";
       reg = <0x2c>;
        ti,dsi-lanes = <4>;
        ti,lvds-format = <2>;
        ti,lvds-bpp = <24>;
        ti,width-mm = <376>;
        ti,height-mm = <301>;
 
        enable-gpios = <&gpio1 14  GPIO_ACTIVE_HIGH>;
        pinctrl-names = "default";
        pinctrl-0 = <&pinctrl_dsi_lvds_bridge>;
        status = "okay";
 
       display-timings {
            lvds {
/*
                clock-frequency = <90000000>;
               hactive = <1280>;
                hsync-len = <54>;
                hback-porch = <75>;
                hfront-porch = <75>;
                vactive = <1024>;
                vsync-len = <10>;
                vback-porch = <10>;
                vfront-porch = <22>;
 
                vsync-active = <0>;
                hsync-active =<0>;
                de-active =<0>;
                pixelclk-active =<0>;
*/
                         clock-frequency = <108000000>;
                         hactive = <1280>;
                         hsync-len = <28>;
                         hback-porch = <200>;
                         hfront-porch = <180>;
                         vactive = <1023>;
                         vsync-len = <7>;
                         vback-porch = <30>;
                         vfront-porch = <5>;
 
                         vsync-active = <0>;
                         hsync-active =<0>;
                         de-active =<0>;
                         pixelclk-active =<0>;
 
           };
        };
 
        port {
           sn65dsi83_in: endpoint {
                remote-endpoint = <&dsim_to_sn65dsi8>;
           };
        };
    };
 
};
after compiling and deploying the kernel using 

bitbake -c compile -f linux-imx and bitbake -c deploy -f linux-imx then I have built entire image using bitbake imx-image-full. I cannot see any display on the LVDS ,can you help me where i was struck.

 
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4 Replies

970 Views
Zhiming_Liu
NXP TechSupport
NXP TechSupport

Hi @VinithNama 

 

PLS share your log

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966 Views
VinithNama
Contributor III

Hi Sir,

           Below image shows the log of my uboot.

 

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961 Views
Zhiming_Liu
NXP TechSupport
NXP TechSupport

Hi @VinithNama 

 

Can you confirm that your hardware is working fine?

Try to use Oscilloscope capture the i2c wave.

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874 Views
VinithNama
Contributor III

Hi Sir,

 I can able to read the i2c registers and I'm getting the reset value my i2c is working but I'm not able to get any signal in oscilloscope.

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