RK3288如何增加双屏异显 eDP+LVDS

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CPU：RK3288

系统：Android 5.1

下面是官方文档中的信息。

1、rk3288 支持的显示接口可以任意组合。

2、双屏异显时，一个显示接口当主屏，另一个当副屏；主副屏由板级 dts 文件确定，启动后无法动态更改。

3、当两路显示接口显示不同分辨率时，rk3288 只能为一路显示接口提供精确时钟，另一路显示接口时钟会有微小频偏。

瑞芯微虽然提供了 Android 5.1 的补丁，但是本人在移植过程中出现一些问题（打补丁最好一行行核对，不要图方便直接使用指令）。

设备 eDP 为主屏，lvds 为副屏。

（1）首先修改两个屏参文件 lcd-xxx.dtsi。

eDP 屏参文件补丁

diff --git a/kernel/arch/arm/boot/dts/lcd-NV116FH1.dtsi b/kernel/arch/arm/boot/dts/lcd-NV116FH1.dtsi

index 3862b05..7bf992f 100755

--- a/kernel/arch/arm/boot/dts/lcd-NV116FH1.dtsi

+++ b/kernel/arch/arm/boot/dts/lcd-NV116FH1.dtsi

@@ -3,11 +3,9 @@

  *

  */

-/ {

-

-        disp_timings: display-timings {

-                        native-mode = <&timing0>;

-                        timing0: timing0 {

+        display-timings {

+                        native-mode = <&nv116fhm>;

+                        nv116fhm: timing0 {

                 screen-type = <SCREEN_EDP>;

                 out-face    = <OUT_P666>;

                 clock-frequency = <205000000>;

@@ -30,4 +30,3 @@

                swap-gb = <0>;

                         };

               };

-};

lvds 屏参文件补丁

diff --git a/kernel/arch/arm/boot/dts/lcd-ZJ080NA-08A.dtsi b/kernel/arch/arm/boot/dts/lcd-ZJ080NA-08A.dtsi

old mode 100644

new mode 100755

index fc6385c..58f999be

--- a/kernel/arch/arm/boot/dts/lcd-ZJ080NA-08A.dtsi

+++ b/kernel/arch/arm/boot/dts/lcd-ZJ080NA-08A.dtsi

@@ -3,11 +3,10 @@

  *

  */

-/ {

-        disp_timings: display-timings {

-                        native-mode = <&timing0>;

-                        timing0: timing0 {

+        display-timings {

+                        native-mode = <&zj080na>;

+                        zj080na: timing0 {

                 screen-type = <SCREEN_DUAL_LVDS>;

                 lvds-format = <LVDS_8BIT_1>;

                 out-face    = <OUT_P888>;

@@ -30,4 +30,3 @@

                swap-gb = <0>;

             };

         };

-};

（2）根据官方提供，打上 kernel 补丁

 kernel 补丁

（3）根据官方提供，打上 hardware 补丁

 hardware 补丁

（4）根据官方提供，打上 framework 补丁

 framework 补丁

（5）官方提供的补丁打完了，但是此时编译可能会报错，如下：

cts/tests/tests/view/src/android/view/cts/WindowTest.java:846: error: WindowTest.MockWindow is not abstract and does not override abstract method moveExtendDisplay() in Window

public class MockWindow extends Window {

^

Note: Some input files use or override a deprecated API.

Note: Recompile with -Xlint:deprecation for details.

1 error

make: *** [out/target/common/obj/APPS/CtsViewTestCases_intermediates/classes-full-debug.jar] Error 41

make: *** Waiting for unfinished jobs....

Note: Some input files use or override a deprecated API.

Note: Recompile with -Xlint:deprecation for details.

Note: Some input files use unchecked or unsafe operations.

Note: Recompile with -Xlint:unchecked for details.

Note: Some input files use or override a deprecated API.

Note: Recompile with -Xlint:deprecation for details.

Note: Some input files use unchecked or unsafe operations.

Note: Recompile with -Xlint:unchecked for details.

Warning: AndroidManifest.xml already defines minSdkVersion (in http://schemas.android.com/apk/res/android); using existing value in manifest.

Warning: AndroidManifest.xml already defines targetSdkVersion (in http://schemas.android.com/apk/res/android); using existing value in manifest.

#### make failed to build some targets (03:55 (mm:ss)) ####

根据编译错误提示，需要修改 cts/tests/tests/view/src/android/view/cts/WindowTest.java 文件。

diff --git a/cts/tests/tests/view/src/android/view/cts/WindowTest.java b/cts/tests/tests/view/src/android/view/cts/WindowTest.java

index 3c5386d..8732ae7 100755

--- a/cts/tests/tests/view/src/android/view/cts/WindowTest.java

+++ b/cts/tests/tests/view/src/android/view/cts/WindowTest.java

@@ -998,6 +998,19 @@ public class WindowTest extends ActivityInstrumentationTestCase2<WindowCtsActivi

         }

         @Override

+        public void moveAppToDisplay(int id) {

+        }

+

+        @Override

+        public void syncDualDisplay() {

+        }

+

+        @Override

+        public void moveExtendDisplay() {

+        }

+

+

+        @Override

         public void setDefaultWindowFormat(int format) {

             super.setDefaultWindowFormat(format);

         }

（6）此时可以编译成功，在屏参正确的前提下，主屏显示正常，副屏出现花屏，需要在 system.prop 里添加属性 ro.htg.force=1。

diff --git a/device/rockchip/rk3288/system.prop b/device/rockchip/rk3288/system.prop

index 26a2b09..c4f2c3d 100755

--- a/device/rockchip/rk3288/system.prop

+++ b/device/rockchip/rk3288/system.prop

@@ -12,6 +12,7 @@ rild.libpath=/system/lib/libril-rk29-dataonly.so

 rild.libargs=-d /dev/ttyACM0

 persist.tegra.nvmmlite = 1

 ro.audio.monitorOrientation=true

+ro.htg.force=1

 #NFC

 debug.nfc.fw_download=false

此时大功告成，双屏可以正常显示，也可以实现双屏异显。

如果 lcd 出现重复性黑屏亮屏，找到对应的屏参文件，在正常范围内调节频率 clk 值即可。

display-timings {

                        native-mode = <&ee101ia>;

                        ee101ia: timing0 {

                screen-type = <SCREEN_DUAL_LVDS>;

                lvds-format = <LVDS_8BIT_1>;

                out-face    = <OUT_P888>;

                color-mode = <COLOR_RGB>;

                // 调节 lcd 频率

                clock-frequency = <148500000>;

                hactive = <1920>;

                vactive = <1080>;

如果单屏调试都正常点亮，打补丁后，点不亮或者有花屏现象，尝试增大对应屏的电源使能延时 

 lcd_en {

    rockchip,power_type = <GPIO>;

    gpios = <&gpio7 GPIO_A5 GPIO_ACTIVE_HIGH>;

-   rockchip,delay = <10>;

+   rockchip,delay = <100>;

};

上述就是小编为大家分享的RK3288如何增加双屏异显 eDP+LVDS了，如果刚好有类似的疑惑，不妨参照上述分析进行理解。如果想知道更多相关知识，欢迎关注亿速云行业资讯频道。