beaglebone black 液晶屏　蓝色和红色颜色交换

原理图LCD RGB888的24位线是怎么和LCD相连的？

原理图附在了附件中．

另外，使用了下面的dts 文件，红色和蓝色是交换的．

/dts-v1/;

/include/ "am33xx.dtsi"

/include/ "am335x-bone-common.dtsi"

&am33xx_pinmux {
   rstctl_pins: pinmux_rstctl_pins {
      pinctrl-single,pins = <
         /* eMMC_RSTn */
         0x50 0x17  /* gpmc_a4.gpio1_20, OUTPUT | MODE7 | PULLUP */
      >;
   };
};

&ldo3_reg {
   regulator-min-microvolt = <1800000>;
   regulator-max-microvolt = <1800000>;
   regulator-always-on;
};

&rstctl {
   status = "okay";
   compatible = "gpio-rctrl";
   pinctrl-names = "default";
   pinctrl-0 = <&rstctl_pins>;

   #reset-cells = <2>;

   gpios = <&gpio2 20 0x00>;
   gpio-names = "eMMC_RSTn";
};

&mmc1 {
   vmmc-supply = <&vmmcsd_fixed>;
};

&mmc2 {
   vmmc-supply = <&vmmcsd_fixed>;
   bus-width = <8>;
   ti,non-removable;
   status = "disabled";

   reset = <&rstctl 0 0>;
   reset-names = "eMMC_RSTn-CONSUMER";
};


&cpu {
   /*
    * To consider voltage drop between PMIC and SoC,
    * tolerance value is reduced to 2% from 4% and
    * voltage value is increased as a precaution.
    */
   operating-points = <
      /* kHz    uV */
      1000000    1350000
      800000 1300000
      600000  1112000
      300000   969000
   >;
};

－－－

使用下面的内容，红色和蓝色没有交换．目前，因为要使用下面文件中的其它内容，所以，需要确定哪个参数会直接影响红色和蓝色的顺序，然后修改，不能直接使用上面的文件．　　　

&lcdc {
   status = "okay";

   /* If you want to get 24 bit RGB and 16 BGR mode instead of
    * current 16 bit RGB and 24 BGR modes, set the propety
    * below to "crossed" and uncomment the video-ports -property
    * in tda19988 node.
    */
   /* blue-and-red-wiring = "straight"; */
   blue-and-red-wiring = "crossed";

   port {
      lcdc_0: endpoint@0 {
         remote-endpoint = <&hdmi_0>;
      };
   };
};

&i2c0 {
   tda19988: tda19988 {
      compatible = "nxp,tda998x";
      reg = <0x70>;


      /* Convert 24bit BGR to RGB, e.g. cross red and blue wiring */
      video-ports = <0x234501>;

      #sound-dai-cells = <0>;
      audio-ports = <    AFMT_I2S   0x03>;

      ports {
         port@0 {
            hdmi_0: endpoint@0 {
               remote-endpoint = <&lcdc_0>;
            };
         };
      };
   };
};

我把原理图贴上来了，　帖子还没有出现．

另外，使用了下面的dts 文件，红色和蓝色是交换的．

/dts-v1/;

/include/ "am33xx.dtsi"

/include/ "am335x-bone-common.dtsi"

&am33xx_pinmux {
   rstctl_pins: pinmux_rstctl_pins {
      pinctrl-single,pins = <
         /* eMMC_RSTn */
         0x50 0x17  /* gpmc_a4.gpio1_20, OUTPUT | MODE7 | PULLUP */
      >;
   };
};

&ldo3_reg {
   regulator-min-microvolt = <1800000>;
   regulator-max-microvolt = <1800000>;
   regulator-always-on;
};

&rstctl {
   status = "okay";
   compatible = "gpio-rctrl";
   pinctrl-names = "default";
   pinctrl-0 = <&rstctl_pins>;

   #reset-cells = <2>;

   gpios = <&gpio2 20 0x00>;
   gpio-names = "eMMC_RSTn";
};

&mmc1 {
   vmmc-supply = <&vmmcsd_fixed>;
};

&mmc2 {
   vmmc-supply = <&vmmcsd_fixed>;
   bus-width = <8>;
   ti,non-removable;
   status = "disabled";

   reset = <&rstctl 0 0>;
   reset-names = "eMMC_RSTn-CONSUMER";
};


&cpu {
   /*
    * To consider voltage drop between PMIC and SoC,
    * tolerance value is reduced to 2% from 4% and
    * voltage value is increased as a precaution.
    */
   operating-points = <
      /* kHz    uV */
      1000000    1350000
      800000 1300000
      600000  1112000
      300000   969000
   >;
};

－－－

使用下面的内容，红色和蓝色没有交换．现在不太确定哪个参数会直接影响红色和蓝色的顺序．　

&lcdc {
   status = "okay";

   /* If you want to get 24 bit RGB and 16 BGR mode instead of
    * current 16 bit RGB and 24 BGR modes, set the propety
    * below to "crossed" and uncomment the video-ports -property
    * in tda19988 node.
    */
   /* blue-and-red-wiring = "straight"; */
   blue-and-red-wiring = "crossed";

   port {
      lcdc_0: endpoint@0 {
         remote-endpoint = <&hdmi_0>;
      };
   };
};

&i2c0 {
   tda19988: tda19988 {
      compatible = "nxp,tda998x";
      reg = <0x70>;


      /* Convert 24bit BGR to RGB, e.g. cross red and blue wiring */
      video-ports = <0x234501>;

      #sound-dai-cells = <0>;
      audio-ports = <    AFMT_I2S   0x03>;

      ports {
         port@0 {
            hdmi_0: endpoint@0 {
               remote-endpoint = <&lcdc_0>;
            };
         };
      };
   };
};

你的原理图并没有看出来LCD RGB具体连的AM335x哪些信号线。

有没有方法在DTB中交换红蓝的开关呢，除了我上面贴出来的．

你看过我们的errata的section 3.1.1么？检查下RGB888数据线的接法。

这个和dts没什么关系的。

按理说颜色翻转只有RGB888和RGB565的区别。

我解释不了原因，不知道谁能帮忙解释一下。