Issue in writing to panel at uboot

[sd05]

Hello Community members,

We want to display image at uboot to show the battery status.  We are using a ST7703 based panel and IMX8MM based customboard. We have successfully ported the drivers for our uboot version.

But we are not able to get the panel up. We tried giving all pixel on and we were getting the white screen.

We tried writing the raw data at uboot and we found that the data was properly written on to the frame buffer. So the question that is there any way using mipi dsi generic read/write to read and verify the pixel stream is transmitted properly or not. Or, alternatively is there any way to read/write directly to the panel buffer using mipi generic read/write command.

Or any other pointers are welcome!

Thanks

[sd05]

thanks @igorpadykov  but init sequence is proper we are able to get the panel up at the kernel and even in uboot giving all pixel on command we are able to see the white screen on the display.

Is there anything else that can be responsible?

[igorpadykov]

also one can check clocks, if panel is working in linux, dump plls and make the same settings in uboot.

Best regards
igor

[igorpadykov]

Hi Sunidhi

it is necessary to use initialization sequence  and specific commands described in that LCD datasheet,

use as example rm67191 driver (its init sequence is in "cmd_set_table")

https://source.codeaurora.org/external/imx/uboot-imx/tree/drivers/video/raydium-rm67191.c?h=lf_v2021...

https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm64/boot/dts/freescale/imx8mm-evk-r...

Best regards
igor