imx8mp screen rotation using kernel

[jemish_1990]

Hi All,

We are using IMX8MP based board for our product. We are using kernel 6.6.36 for our development. We are using LCD screen which has by default 1080x1920 resolution.  In our product LCD is in landscape mode (1920x1080). Currently we are using compositor for rotation purpose but we have touch and other performance issues.

At this stage we can't change LCD. So we are exploring alternative options. Is there any API/bootargs or way using which we can do rotation from kernel. We already tried the option : video=DSI-1:1920x1080M@60,rotate=90 but that didn't help.

Any suggestions or pointers in this direction will be helpful.

Thanks,

Jemish

[jemish_1990]

Hi Salas,

If no further suggestion then I think we can close this discussion.

Thanks,

Jemish

[jemish_1990]

Hi Salas,

Thank you for your response.

Following are LCD specific changes in device tree:

&mipi_dsi {
status = "okay";
panel@0 {
compatible = "kingsfield,hx8399c";
reg = <0>;
pinctrl-0 = <&pinctrl_mipi_dsi_en>;
gpio-reset = <&gpio1 14 GPIO_ACTIVE_HIGH>;
gpio-3v3 = <&gpio3 19 GPIO_ACTIVE_HIGH>;
gpio-1v8 = <&gpio4 26 GPIO_ACTIVE_HIGH>;
gpio-bak-domain = <&gpio3 16 GPIO_ACTIVE_HIGH>;
dsi-lanes = <4>;
video-mode = <2>; /* 0: burst mode
* 1: non-burst mode with sync event
* 2: non-burst mode with sync pulse
*/
panel-width-mm = <68>;
panel-height-mm = <121>;
status = "okay";
};
};

Regarding your suggestion to modify LCD driver. We already tired to look into that direction, but didn't find any configuration in LCD controller for such rotation.

In past when we were using IMX6Q we used to do rotation using frame buffer driver using IPU. For reference I am putting my past comment here

https://community.nxp.com/t5/i-MX-Processors/i-MX6-IPU-and-rotating-a-frame-buffer/m-p/269943#M28863

Do we have similar way to rotation using GPU via DRM mechanism? Does anyone has done rotation earlier in IMX8MP using kernel?

Thanks,

Jemish

[jemish_1990]

Hi @Manuel_Salas ,

Do you have any suggestion for this?

Thanks,

Jemish

[Manuel_Salas]

Hello @jemish_1990 

Apologies, I have not suggestion, as the kingsfield,hx8399c driver is not on our official BSP source code, I can not be sure how you can perform rotation.

Best regards,

Salas.

[Manuel_Salas]

Hello @jemish_1990 

I hope you are doing very well.

If you can share your device tree related to LCD, it would be very helpful.

Also, the most possible is you will need to modify the LCD driver to make the rotation.

Best regards,

Salas.

[jemish_1990]

Hi All,

Does anyone any inputs or suggestions to share? Can anyone tell us if it is feasible to do that with our kernel or not?

Thanks,

Jemish