The LVDS Display Bridge (LDB) connects the Display Processing Unit (DPU) to an external LVDS display interface.
On the ConnectCore 8X SBC Express:
-
There is one LVDS display connector.
On the ConnectCore 8X SBC Pro:
-
There are two LVDS display connectors.
Kernel configuration
You can manage the LDB support through the following kernel configuration option:
-
Support for LVDS displays (CONFIG_DRM_IMX_LDB)
This option is enabled as built-in on the default ConnectCore 8X kernel configuration file.
Kernel driver
The driver for the LDB interface is located at:
| File | Description |
|---|---|
i.MX LDB driver |
Device tree bindings and customization
The i.MX8QXP LDB interface is documented at Documentation/devicetree/bindings/display/imx/ldb.txt. The LDB interface is defined in the i.MX8QXP CPU, ConnectCore 8X SBC Express, and ConnectCore 8X SBC Pro device tree files.
Example: LVDS display bridge 1 (LDB1) on ConnectCore 8X SBC Express
Definition of the LDB1
ldb1: ldb@562210e0 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "fsl,imx8qxp-ldb";
clocks = <&clk IMX8QXP_MIPI0_LVDS_PIXEL_CLK>,
<&clk IMX8QXP_MIPI0_LVDS_BYPASS_CLK>;
clock-names = "pixel", "bypass";
power-domains = <&pd_mipi_dsi0>;
gpr = <&lvds_region1>;
status = "disabled";
lvds-channel@0 {
#address-cells = <1>;
#size-cells = <0>;
reg = <0>;
phys = <&ldb1_phy>;
phy-names = "ldb_phy";
status = "disabled";
port@0 {
reg = <0>;
ldb1_ch0: endpoint {
remote-endpoint = <&dpu_disp0_lvds0_ch0>;
};
};
};
lvds-channel@1 {
#address-cells = <1>;
#size-cells = <0>;
reg = <1>;
phys = <&ldb1_phy>;
phy-names = "ldb_phy";
status = "disabled";
port@0 {
reg = <0>;
ldb1_ch1: endpoint {
remote-endpoint = <&dpu_disp0_lvds0_ch1>;
};
};
};
};IOMUX configuration
The LVDS interfaces use dedicated pins. No IOMUX configuration is necessary. There is an IOMUX entry for associated GPIO pins.
pinctrl_lvds0: lvds0grp {
fsl,pins = <
/* LVDS0 touch interrupt */
SC_P_USDHC1_RESET_B_LSIO_GPIO4_IO19 0x06000020
/* LVDS0 PWM backlight (as GPIO) */
SC_P_MIPI_DSI0_GPIO0_00_LSIO_GPIO1_IO27 0x06000020
>;
};LVDS channels
&ldb1 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_lvds0>;
status = "okay";
lvds0: lvds-channel@0 {
fsl,data-mapping = "jeida";
fsl,data-width = <24>;
status = "okay";
display-timings {
native-mode = <&g101evn010_1>;
/* AUO G101EVN01.0 */
g101evn010_1: timing@0 {
clock-frequency = <68930000>;
hactive = <1280>;
vactive = <800>;
hfront-porch = <120>;
hback-porch = <0>;
hsync-len = <8>;
vback-porch = <10>;
vfront-porch = <0>;
vsync-len = <6>;
hsync-active = <1>;
vsync-active = <1>;
de-active = <1>;
pixelclk-active = <0>;
};
};
};
};Using the video interface
When the video interface is available, a bootup logo displays on the screen. For XWayland images, a Weston desktop launches after Linux starts.
Playing a video
To play a video using Gstreamer:
~# gplay-1.0 /tmp/myvideo.mp4
