How to Config Multi-Display RK3568

RK3399 has 3 VPorts.

RSB-4810 surport 4 types display : eDP、LVDS、HDMI、MIPI.

Note：

1. HDMI、eDP、MIPI MUST be set to port 0 and port 1.

2. LVDS MUST be set to port 1 and port 2.

3. LVDS and MIPI are alternative.

Enter U-boot interrupt mode

Connect device to debug port, and open debug console. See more : How_to_debug.

Press "ctrl + c" key before power up the device, until get the following information on debug console :

Hit any key to stop autoboot: 0
=> <INTERRUPT>
=>

Then you can input the following cammand to config Multi-Display.

Module	Sub Module	Step
Single	HDMI	fw_setenv display0 hdmi-default fw_setenv display1 fw_setenv display2
	LVDS	fw_setenv display0 fw_setenv display1 lvds-g070vw01 fw_setenv display2
	eDP	fw_setenv display0 edp-1366x768 fw_setenv display1 fw_setenv display2
	MIPI	fw_setenv display0 mipi-gl0uan fw_setenv display1 fw_setenv display2
Dual	HDMI+LVDS	fw_setenv display0 hdmi-default fw_setenv display1 lvds-g070vw01 fw_setenv display2
	HDMI+eDP	fw_setenv display0 hdmi-default fw_setenv display1 edp-1366x768 fw_setenv display2
	eDP+LVDS	fw_setenv display0 edp-1366x768 fw_setenv display1 lvds-g070vw01 fw_setenv display2
	HDMI+MIPI	fw_setenv display0 hdmi-default fw_setenv display1 mipi-gl0uan fw_setenv display2
	eDP+MIPI	fw_setenv display0 edp-1366x768 fw_setenv display1 mipi-gl0uan fw_setenv display2
Triple	HDMI+eDP+LVDS	fw_setenv display0 hdmi-default fw_setenv display1 edp-1366x768 fw_setenv display2 lvds-g070vw01

NOTE :

1. The name of the panel must begin with "edp-"、"lvds-" 、"hdmi-" or “dp-”.

And it can be found in "kernel/include/dt-bindings/display/screen-timing/{LCDNAME}.dtsi" like :

lvds_g070vw01: lvds-g070vw01

2. If there is no configuration, you will get default setting :

hdmi-default and dp-default as default setting.

3. Check your configuration in Terminal or debug console.

cat /proc/cmdline
... prmry_screen=hdmi-default extend_screen=dp-default

Using envtools to setup envs in Debian/Android OS is very similar in uboot.

Take “eDP+HDMI”for example :

In uboot	In Debian/Android
setenv prmry_screen hdmi-default	fw_setenv prmry_screen hdmi-default
setenv extend_screen edp-1920x1080	fw_setenv extend_screen edp-1920x1080
saveenv
reset	reboot

Note :

The tool "fw_setenv" will save envs automatically in Debian/Android OS, so it isn't necessary to saveen manually.