Timings for Ampire lcd with imx8mp

[Destel]

Hi,

I'm trying to set timings of the lcd AM-19201080D1TZQW-T02H in order to connect display to an embedded board with IMX8MP processor.

I customized device tree node with the following values, read in the display specification:

panel_lvds: panel-lvds {

compatible = "panel-lvds";

width-mm = <210>;

height-mm = <158>;

data-mapping = "vesa-24";

status = "okay";

panel-timing {

clock-frequency = <70930000>;

hactive = <960>;

vactive = <1080>;

hfront-porch = <430>;

hback-porch = <105>;

vfront-porch = <30>;

vback-porch = <0>;

                        de-active = <1>;

                        hsync-active = <0>;

                        vsync-active = <0>;

};

port {

panel_in_lvds: endpoint {

remote-endpoint = <&lvds0_out>;

};

&ldb {

status = "okay";

        fsl,dual-channel;

lvds-channel@0 {

fsl,data-mapping = "spwg";

fsl,data-width = <24>;

status = "okay";

port@1 {

reg = <1>;

lvds0_out: endpoint {

remote-endpoint = <&panel_in_lvds>;

};

};

};

};

};

};

With these configuration display does not work. Sometimes display turn on with only a green backlight.

The timing specifications are: 

What am I doing wrong?

Can you help me?

Thanks and regard

[Zhiming_Liu]

Hi @Destel 

1.hactive should be 1920, the other horizontal parameters should be double.

2.You need add new PLL RATE in imx_pll1443x_tbl, PLL VALUE=PIXEL CLOCK *7 （dual channel mode）

drivers/clk/imx/clk-pll14xx.c

static const struct imx_pll14xx_rate_table imx_pll1443x_tbl[] = {
	PLL_1443X_RATE(1039500000U, 173, 2, 1, 16384),
	PLL_1443X_RATE(650000000U, 325, 3, 2, 0),
	PLL_1443X_RATE(594000000U, 198, 2, 2, 0),
	PLL_1443X_RATE(519750000U, 173, 2, 2, 16384),
	PLL_1443X_RATE(393216000U, 262, 2, 3, 9437),
	PLL_1443X_RATE(361267200U, 361, 3, 3, 17511),
};

For pkms parameters, you can calculate it from page 265 in RM

[Destel]

Hi,

I don't think it's a pll rate problem. I modified timing values  with the following suggested by supplier:

panel-timing {
clock-frequency = <141000000>;
hactive = <1920>;
vactive = <1080>;
hsync-len = <22>;
hfront-porch = <100>;
hback-porch = <100>;
vsync-len = <2>;
vfront-porch = <10>;
vback-porch = <8>;

de-active = <0>;
hsync-active = <0>;
vsync-active = <0>;
pixelclk-active = <0>;
swap-rb = <0>;
swap-rg = <0>;
swap-gb = <0>;
};

Now monitor is working, but flickering problem on monitor still remain. Maybe some settings are wrong?

Can you help me?