AM3354: LCD timing issues

Hi,

What software are you using? Which version? Where did you get this spreadsheet from?

Hi Biser,

SDK 03.03.04 (Kernel 4.4.41) , Spread sheet we have calculated..

All HSD's calculated with respect to DCLK, All VSD's calculated with respect to HSD timings.

Regards
Sujay A

Biser,

We have gone through this and configured the panel parameters...

panel {
compatible = "ti,tilcdc,panel";
status = "okay";
pinctrl-names = "default";
pinctrl-0 = <&lcd_pins_s0>;
panel-info {
ac-bias = <255>;
ac-bias-intrpt = <0>;
dma-burst-sz = <16>;
bpp = <24>;
fdd = <0x80>;
sync-edge = <0>;
sync-ctrl = <1>;
raster-order = <0>;
fifo-th = <0>;
};

display-timings {
native-mode = <&timing0>;
timing0: 800x480p62 {
clock-frequency = <30000000>;
hactive = <800>;
vactive = <480>;
hfront-porch = <40>;
hback-porch = <88>;
hsync-len = <48>;
vback-porch = <32>;
vfront-porch = <13>;
vsync-len = <3>;
hsync-active = <0>;
vsync-active = <0>;
de-active = <1>;

};
};
};

But still we are not getting anything on the LCD but the white back light. Anything else we need to take care ? When probed the data lines and clock looks fine.

Regards,
Sujay

We cannot say anything without seeing the LCD datasheet. Can you post that?

Hi Biser

LCD Datasheet-AT-T062HWH-01CP Spec.pdf

Regards

Sujay A

Can you try adding in the panel node:

pixelclk-active=<1>

Hi Biser,

We have tried adding the above in panel node of DTS file, however result is same (Nothing on LCD).

Please let us know if any other suggestions.

Regards
Sujay A

Maybe a stupid question, but have you loaded anything to display?

Hi Biser,

We tried MODETEST
also tried cat /dev/urand > /dev/fb0

However, nothing is on display. Ideally matrix should come up.

Regards
Sujay A

I have asked the software team to look at this. They will respond here.

Hi,

Have you enabled the lcdc? I was not able to see it in the shared dts pieces of code..
Can you attach your dts file?

Best Regards,
Yardan

Hi Yardan,

LCDC is enabled, Please find the attached DTS file -am335x-evm.zip

Regards

Sujay A

Hi Yardan,

In the attached DTS file- LCD panel

compatible = "ti,tilcdc,panel";
//compatible = "himax,hx8357b", "himax,hx8357";

Regards
Sujay A

Hi,

Sorry for the late reply.

You're using similar display as in am3335x-evm, right? I see all timings & drivers are the same in your dts.

Also the dts seems correct. Have you verified your hardware connections on the board?

Best Regards,
Yordan

Hi Yordan,

yes, hardware is fine. We had connected am3335x-evm LCD. it worked and we were able to see the matrix GUI,

but its not working for ATOP LCD.

Can you please attach the AM335x-evm LCD datasheet.

Regards
Sujay A