9.2.3. MIPI屏调试配置

9.2.3.1. 概述

相比RGB和LVDS屏的调试，MIPI屏的调试相对稍微繁琐，不仅需要在DTS中设置参数，还需要在kernel中添加屏幕所对应的驱动。此章节详细的描述一款MIPI显示屏的调试过程和配置方法。

9.2.3.2. 内核配置

驱动源码目录：linux-5.10/drivers/video/fbdev/zx/panel/

9.2.3.3. DTS参数配置

这些参数主要在文件board.dts中，功能参数的设置必须和硬件原理图相匹配

首先设置显示模块数据通路关系，RGB屏幕数据通路如下：

&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 = <&dsi0_in>;
                };
        };
};

&dsi0 {
    status = "okay";
    pinctrl-names = "default";
    pinctrl-0 = <&dsi_pins>;

    port@0 {
        reg = <0>;
        dsi0_in: endpoint {
            remote-endpoint = <&de0_out>;
        };
    };

    port@1 {
        reg = <1>;
        dsi0_out: endpoint {
            remote-endpoint = <&panel_dsi_in>;
        };
    };
};

在上述例子中，board.dts通过port和status结点，定义了一条数据通道。

fb       |      de    |     |     dsi    |     panel
port  --> port0   port1 -->  port0   port1 -->  port

如果board.dts中没有正确定义一条数据通道，显示驱动可能无法完成初始化。

设置屏幕参数

    panel_dsi {
    compatible = "zx,aic-dsi-panel-simple";
    status = "disabled";

    dcdc-en-gpios  = <&gpio_p 0 GPIO_ACTIVE_HIGH>;
    reset-gpios  = <&gpio_p 1 GPIO_ACTIVE_HIGH>;
    enable-gpios = <&gpio_d 3 GPIO_ACTIVE_HIGH>;

    port {
        panel_dsi_in: endpoint {
            remote-endpoint = <&dsi0_out>;
        };
    };

    display-timings {
                    native-mode = <&timing1>;
                    timing1: 800x480 {
                            clock-frequency = <60000000>;
                            hactive = <800>;
                            vactive = <480>;
                            hback-porch = <35>;
                            hfront-porch = <20>;
                            hsync-len = <4>;
                            vback-porch = <20>;
                            vfront-porch = <10>;
                            vsync-len = <4>;
                            de-active = <1>;
                            pixelclk-active = <1>;
                    };
            };
};