40-RK3568 LCD Configuration

RK3568 is equipped with four display output interfaces, namely HDMI, MIPI, LVDS, EDP, of which up to three simultaneous display outputs are supported

1. Display interface resource introduction

RK3568

RK3568 has three VP nodes, and each VP node can be connected to a display screen. The corresponding relationship is shown in the table below

VP Number	VP Support Display Interface	VP Maximum Resolution
VP0	MIPI0/MIPI1/HDMI/EDP	4096x2304@60Hz
VP1	MIPI0/MIPI1/LVDS/HDMI/EDP	2048x1536@60Hz
VP2	LVDS/RGB	1920x1080@60Hz

MIPI0 conflicts with LVDS interface pins, only one can be selected

The VP2 node only supports LVDS/RGB, so one of the three-screen displays must be LVDS (the RGB interface is not introduced).

Display Interface	Display Maximum Resolution	Format
HDMI	4096x2160@60Hz	RGB/YUV420 10Bit
MIPI	1920x1080@60Hz	RGB 8Bit
Dual MIPI	2560x1440@60Hz	RGB 8Bit
LVDS	1280x800@60Hz	RGB 8Bit
EDP	2560x1600@60Hz	RGB 10Bit
RGB	1920x1080@60Hz	RGB 8Bit

2. Single display driver configuration

Display configuration, mainly modify the device tree LCD configuration file, RK3568 device tree LCD configuration directory is as follows:

$ vim kernel/arch/arm64/boot/dts/rockchip/rk3568-kickpi-k1.dtsi //linux
$ vim kernel-5.10/arch/arm64/boot/dts/rockchip/rk3568-kickpi-k1.dtsi //android

// LCD
//#include "rk3568-kickpi-lcd-hdmi.dtsi"
//#include "rk3568-kickpi-lcd-edp-15.6-1920-1080.dtsi"
//#include "rk3568-kickpi-lcd-mipi0-10.1-800-1280.dtsi"
#include "rk3568-kickpi-lcd-mipi1-10.1-800-1280.dtsi"
//#include "rk3568-kickpi-lcd-lvds-7-1024-600.dtsi"

If there is a problem with the debugging of the display screen, you can contact the after-sales service for technical support.

MIPI

The RK3568 has two MIPI LCDs, MIPI0 and MIPI1, of which MIPI0 is multiplexed with LVDS

MIPI0 interface, reference rk3568-kickpi-lcd-mipi0- 10.1-800 -1280.dtsi

MIPI1 interface, reference rk3568-kickpi-lcd-mipi1- 10.1-800 -1280.dtsi

LVDS

LVDS interface, refer to rk3568-kickpi-lcd-lvds-7-1024-600

EDP

EDP interface, reference rk3568-kickpi-lcd-edp- 15.6-1920 -1080.dtsi

3. Multi-screen display system configuration

In the multi-screen display scheme, LCD parameter selection precautions:

It is recommended to choose a display screen with the same length-width ratio, otherwise the picture will be stretched or the picture will be black.

Kernel Device Tree Configuration

$ vim kernel/arch/arm64/boot/dts/rockchip/rk3568-kickpi-k1.dtsi

// Triple LCD
//#include "rk3568-kickpi-triple-lcd-hdmi-mipi1-lvds.dtsi"
//#include "rk3568-kickpi-triple-lcd-edp-mipi1-lvds.dtsi"

After completing the single-screen debugging, refer to the multi-screen device tree configuration file provided above

Android multi-screen configuration

• DSI as the main screen, HDMI-A as the secondary screen

PRODUCT_PROPERTY_OVERRIDES += vendor.hwc.device.primary=DSI
PRODUCT_PROPERTY_OVERRIDES += vendor.hwc.device.extend=HDMI-A

• DSI\ eDP as the main screen, LVDS\ HDMI-A as the secondary screen

PRODUCT_PROPERTY_OVERRIDES += vendor.hwc.device.primary=DSI,eDP
PRODUCT_PROPERTY_OVERRIDES += vendor.hwc.device.extend=LVDS,HDMI-A

4. Single touchscreen driver configuration

Take the GT9XX as an example

driver porting

Porting the driver provided by the manufacturer into the SDK directory, and modifying and adding it to the compiled file

The driver file is copied to the touch driver folder under $ (SDK_DIR) \ kernel-5.10\ drivers\ input\ touchscreen

Modify kconfig: add the following

config TOUCHSCREEN_GT9XX
	tristate "GT9XX touchscreens support"

Modify the Makefile: Add the following

obj-$(CONFIG_TOUCHSCREEN_GT9XX)		+= gt9xx/

Kernel Configuration Add CONFIG_TOUCHSCREEN_GT9XX = y

Kernel configuration files such as arch/arm64/configs/rockchip_defconfig, different versions of defconfig please find the corresponding version file in the git history

Kernel Device Tree Configuration

i2c_gt9xx configuration:

&i2c1 {
	status = "okay";
	gt9xx:gt9xx@5d {
		compatible = "goodix,gt9xx";
		status = "okay";
		reg = <0x5d>;

		gtp_resolution_x = <1024>;
		gtp_resolution_y = <600>;
		gtp_int_tarigger = <1>;
		gtp_change_x2y = <0>;
		gtp_overturn_x = <0>;
		gtp_overturn_y = <0>;
		gtp_send_cfg = <1>;
		gtp_touch_wakeup = <1>;
		goodix_rst_gpio = <&gpio0 RK_PB6 GPIO_ACTIVE_HIGH>;
		goodix_irq_gpio = <&gpio3 RK_PA3 IRQ_TYPE_LEVEL_LOW>;
		pinctrl-names = "default";
		pinctrl-0 = <&touch3_gpio>;

		goodix,cfg-group0 = [
			4B 00 04 58 02 01 0D 00 01 08
			28 05 50 32 03 05 00 00 00 00
			00 00 00 00 00 00 00 8B 2A 0C
			17 15 31 0D 00 00 02 BA 03 2D
			00 00 00 00 00 03 00 00 00 00
			00 0F 41 94 C5 02 07 00 00 04
			9B 11 00 77 17 00 5C 1F 00 48
			2A 00 3B 38 00 3B 00 00 00 00
			00 00 00 00 00 00 00 00 00 00
			00 00 00 00 00 00 00 00 00 00
			00 00 00 00 00 00 00 00 00 00
			00 00 02 04 06 08 0A 0C 0E 10
			12 14 16 18 FF FF 00 00 00 00
			00 00 00 00 00 00 00 00 00 00
			00 00 00 02 04 06 08 0A 0C 0F
			10 12 13 16 18 1C 1D 1E 1F 20
			21 22 24 FF FF FF FF FF 00 00
			00 00 00 00 00 00 00 00 00 00
			00 00 00 00 B6 01
		];
	};
};

Rotate the touch direction

Adjust the touch screen orientation based on the device tree. The following directions are only applicable to GT9XX drivers

0 degrees (default)

gt9xx:gt9xx@5d {
	gtp_change_x2y = <0>;		
	gtp_overturn_x = <0>;
	gtp_overturn_y = <0>;
};

90 degrees

gt9xx:gt9xx@5d {
	gtp_change_x2y = <1>;
	gtp_overturn_x = <1>;
	gtp_overturn_y = <0>;
};

180 degrees

gt9xx:gt9xx@5d {
	gtp_change_x2y = <0>;
	gtp_overturn_x = <0>;
	gtp_overturn_y = <1>;
};

270 degrees

gt9xx:gt9xx@5d {
	gtp_change_x2y = <0>;
	gtp_overturn_x = <1>;
	gtp_overturn_y = <0>;
};

5. Multi-screen touch system configuration

Kernel Device Tree Configuration

I2C + I2C

Android single-screen touch configuration

• Android13.0

Prohibit secondary screen touch, regardless of external or internal type of device, it acts on the main screen

$ vim frameworks/native/services/inputflinger/reader/EventHub.cpp

    // Determine whether the device is external or internal.
    if (isExternalDeviceLocked(device)) {
-        device->classes |= INPUT_DEVICE_CLASS_EXTERNAL;
+        //device->classes |= INPUT_DEVICE_CLASS_EXTERNAL;
    }

Android multi-screen touch configuration

• Determine the device name

$ vim frameworks/native/services/inputflinger/reader/EventHub.cpp

bool EventHub::isExternalDeviceLocked(Device* device) {
+	const char *I2C_DEVICE_NAME = "generic ft5x06 (79)";
+	ALOGE("input deviceis '%s' ",device->identifier.name.c_str());
+	if (strcmp(device->identifier.name.c_str(), I2C_DEVICE_NAME) == 0) {
+		return true;
+	}

	if (device->configuration) {
	bool value;
}

• Add IDC configuration file