rk3128 HDMI调试

1.HDMI默认是关闭的，需要打开：

@@ -146,7 +146,7 @@
 };
 
 &hdmi {
-       status = "disabled";
+       status = "okay";
        rockchip,hdmi_audio_source = <0>;
 };

显示配置：

&fb {
    status = "okay";
    rockchip,disp-mode = <NO_DUAL>;
    rockchip,uboot-logo-on = <1>;
};

&rk_screen {
    status = "okay";
    display-timings = <&disp_timings>;
};


&lcdc {
    status = "okay";

    //backlight = <&backlight>;
    pinctrl-names = "default", "gpio";
    pinctrl-0 = <&lcdc0_den>;
    pinctrl-1 = <&lcdc0_sync>;

    rockchip,fb-win-map = <FB_DEFAULT_ORDER>;
    power_ctr: power_ctr {
        rockchip,debug = <0>;
    };
};

2.HDMI有画面出来，但显示比例有问题，需要修改disp_timings的显示分辨率和HDMI的默认分辨率一致：

查看HDMI默认分辨率：

rk3128:/ $ cat /sys/class/display/HDMI/mode
1280x720p-60

drivers/video/rockchip/hdmi/rockchip-hdmi.h代码中定义如下：

 timing的分辨率需要对应是1280x720即可，其他参数可以不用管。

disp_timings: display-timings {
            native-mode = <&timing0>;
            timing0: timing0 {
                screen-type = <SCREEN_RGB>;
                out-face    = <OUT_P888>;
                color-mode = <COLOR_YCBCR>;
                clock-frequency = <74250000>;
                hactive = <1280>;
                vactive = <720>;
                hback-porch = <220>;
                hfront-porch = <110>;
                vback-porch = <20>;
                vfront-porch = <5>;
                hsync-len = <40>;
                vsync-len = <5>;
                hsync-active = <1>;
                vsync-active = <1>;
                de-active = <0>;
                pixelclk-active = <0>;
                swap-rb = <0>;
                swap-rg = <0>;
                swap-gb = <0>;
                size,width = <69>;
                size,height = <114>;
                };
}；

3.画面显示正常，但发现每次拔掉HDMI，串口都会有大量报错，并且设备会是卡死状态。

通过rk的支持，有文档说明如下：

 由于我们设备只用到HDMI显示，是不用接显示屏，所以需要把disp-mode对应设置为NO_DUAL：

diff --git a/arch/arm/boot/dts/rk3128-xzy.dts b/arch/arm/boot/dts/rk3128-xzy.dts
index 90c1397..2261d47 100755
--- a/arch/arm/boot/dts/rk3128-xzy.dts
+++ b/arch/arm/boot/dts/rk3128-xzy.dts
@@ -118,7 +118,7 @@

 &fb {
        status = "okay";
-       rockchip,disp-mode = <ONE_DUAL>;
+       rockchip,disp-mode = <NO_DUAL>;
        rockchip,uboot-logo-on = <1>;
 };

 从新编译烧录测试，发现在热拔插就没有问题了。

当然，如果需要用到双屏显示，需要把disp-mode对应设置为ONE_DUAL，并找rk要相应的补丁。