RGB

4 Dec 2024

Read time: 4 minute(s)

配置 Uboot

在 Luban 根目录下执行 make um，进入 uboot 的功能配置界面，使能显示模块驱动：

Device Drivers
    Graphics support
        ArtInChip Graphics  --->
            [*]   Enable ArtInChip Video Support
            [*]   ArtInChip display rgb support
            [ ]   ArtInChip display lvds support
            [ ]   ArtInChip display mipi-dsi support
            <*>   ArtInChip Panel Drivers (ArtInChip general RGB panel)  --->

配置 Kernel

在 Luban 根目录下执行 make km，进入 Kernel 的功能配置界面，使能显示模块驱动：

Device Drivers
    Graphics support
        ArtInChip Graphics  --->
            <*> ArtInChip Framebuffer support
            [*]   ArtInChip display rgb support
            [ ]   ArtInChip display lvds support
            [ ]   ArtInChip display mipi-dsi support
            <*>   ArtInChip Panel Drivers (ArtInChip general RGB panel)  --->

uboot dts

Uboot 如果要进行显示，则声明相应的配置为预加载，以 demo88_nand 工程为例，文件为 target/d211/demo88_nand/board-u-boot.dtsi

声明通路

&disp {
    u-boot,dm-pre-reloc;
    fb0: fb@0 {
        u-boot,dm-pre-reloc;
        port {
            fb0_out: endpoint {
                u-boot,dm-pre-reloc;
            }
        };
    };
};

&de0 {
    u-boot,dm-pre-reloc;
    port@0 {
        de0_in: endpoint {
            u-boot,dm-pre-reloc;
        };
    };

    port@1 {
        de0_out: endpoint {
            u-boot,dm-pre-reloc;
        };
    };
};
&rgb0 {                             //RGB
    u-boot,dm-pre-reloc;
    port@0 {
        rgb0_in: endpoint {
            u-boot,dm-pre-reloc;
        };
    };

    port@1 {
        rgb0_out: endpoint {
            u-boot,dm-pre-reloc;
        };
    };
};

声明屏幕参数

panel_rgb {
    u-boot,dm-pre-reloc;
    port {
        panel_rgb_in: endpoint {
        u-boot,dm-pre-reloc;
        };
    };

    display-timings {
        u-boot,dm-pre-reloc;
        timing0: 1024x600 {
            u-boot,dm-pre-reloc;
        };
    };
};

声明屏幕引脚

lcd_rgb565_ld_pins: lcd-1 {
    u-boot,dm-pre-reloc;
    pins {
        u-boot,dm-pre-reloc;
    };
};

系统 dts

系统的 dts 将进行完整的功能配置，以 demo88_nand 工程为例，文件为 target/d211/demo88_nand/board.dts ：

配置通路

通过 port 和 status 结点，定义一条数据通道：

fb       |      de    |     |     rgb    |     panel
port  --> port0   port1 -->  port0   port1 -->  port
&fb0 {
    port {
        fb0_out: endpoint {
            remote-endpoint = <&de0_in>;
        };
    };
};

&de0 {
    status = "okay";
    port@0 {
        reg = <0>;
        de0_in: endpoint {
        remote-endpoint = <&fb0_out>;
    };

    port@1 {
        reg = <1>;
        de0_out: endpoint {
            remote-endpoint = <&rgb0_in>;   //RGB
        }
    };
};

&rgb0 {
    pinctrl-names = "default", "sleep";
    pinctrl-0 = <&lcd_rgb565_ld_pins>;          //RGB
    pinctrl-1 = <&lcd_rgb565_ld_sleep_pins>;
    status = "okay";
    port@0 {
        reg = <0>;
        rgb0_in: endpoint {
            remote-endpoint = <&de0_out>;
        }
    };

    port@1 {
        reg = <1>;
        rgb0_out: endpoint {
            remote-endpoint = <&panel_rgb_in>;  //RGB
        };
    };
}

配置屏幕参数

其中类似 enable-gpios 控制引脚需要根据实际显示屏的需要增加或减少，驱动中做相应修改， rgb-mode 和 interface-format 需要从规格书中获取， data-order data-mirror 需要根据板级走线的顺序设置相关参数。 clock-phase 需要根据最终实际的显示效果做相应调整。关于参数详细的解析，参考 Panel_RGB 的配置说明。

panel_rgb {
compatible = "artinchip,aic-general-rgb-panel";
status = "okay";

enable-gpios = <&gpio_e 19 GPIO_ACTIVE_HIGH>;
sleep-gpios = <&gpio_e 15 GPIO_ACTIVE_HIGH>;
rgb-mode = <PRGB>;
interface-format = <PRGB_16BIT_LD>;
clock-phase = <DEGREE_0>;
data-order = <RGB>;
disp-dither = <DITHER_RGB565>;

port {
    panel_rgb_in: endpoint {
    remote-endpoint = <&rgb0_out>;
    };
};

display-timings {
    native-mode = <&timing0>;
    timing0: 1024x600 {
        lock-frequency = <52000000>;
        hactive = <1024>;
        vactive = <600>;
        hback-porch = <160>;
        hfront-porch = <160>;
        hsync-len = <20>;
        vback-porch = <12>;
        vfront-porch = <20>;
        vsync-len = <3>;
        de-active = <1>;
        pixelclk-active = <1>;
    };
};

配置引脚

引脚的配置统一在 d211-pinctrl.dtsi 中完成，在 rgb0 节点中直接进行了引用：

&rgb0 {
    pinctrl-names = "default", "sleep";
    pinctrl-0 = <&lcd_rgb565_ld_pins>;
    pinctrl-1 = <&lcd_rgb565_ld_sleep_pins>;
    status = "okay";
    ......
};