Need advice for i.MX6Q and TFT-LCD via lvds

[vladimirlegosta]

Hello!

I have a problem with connecting TFT-LCD panel to our i.mx6 custom board (with yocto) via lvds.
The panel has resolution 1280 x 1024, but hactive 428.

With settings bellow I have a picture with correct height 1024, but wrong width. The picture is stretched.
        display-timings {
            t_lvds: t_lvds_default {
                clock-frequency = <30200000>;
                hactive = <428>;
                vactive = <1024>;
                hback-porch = <5>;
                hfront-porch = <34>;
                vback-porch = <2>;
                vfront-porch = <51>;
                hsync-len = <1>;
                vsync-len = <3>;
                /*hsync-active = <0>;
                vsync-active = <0>;
                de-active = <1>;
                pixelclk-active = <0>;*/
            };

What is the way to send three dots per clock?
Is it possible? With device tree or with Linux driver?

Thank You!

[joanxie]

since your lcd resolution is 1280 x 1024,why did you set hactive to 428? how about set this to 1280? any improved?

[vladimirlegosta]

Settings 1280 x 1024 give the same result.

Because this monochrome matrix needs 428 clocks to draw 1280 pixels (page 6).
In one clock it draws 3 pixels, but the data isn't updated, so it put one pixel three times.
I think, I need to modify the picture. The picture is colored, where one pixel is 24bit R8G8B8. So I need to transform it to monochrome, where one pixel is 8bit and in one clock there will be 3*8bit pixels.
I think, this can be done in application. And I'm interesting, if it is possible with IPU driver (may be mofided driver).

[joanxie · Accepted solution]

I checked your data sheet on page6, refer to the timings chart,  it seems that imx6q couldn't support this typeTFT, for 24bits, normally imx6q support rgb in one clock,you can refer to the document as below:

https://community.nxp.com/docs/DOC-93617 

refer to your lcd timings, you should change on your application level, on the driver level, you can set rgb888

[vladimirlegosta]

Thank You for the answer!
We came to similar conclusions, to experiment with application