IMX6Q 对micro sd卡的支持&android 开放读写权限

显示SD card不受支持

检查原理图microSD用的是SD3

SD3_DAT0/1/2/3/CLK/CMD

探测引脚SD3_CD_B------>NANDF_D0

1.dts

&usdhc3 {

    pinctrl-names = "default";

    pinctrl-0 = <&pinctrl_usdhc3>;

    bus-width = <4>;

    cd-gpios = <&gpio2 0 GPIO_ACTIVE_LOW>;

    

    no-1-8-v;

    keep-power-in-suspend;

    enable-sdio-wakeup;

    status = "okay";

};

    pinctrl_usdhc3: usdhc3grp {

            fsl,pins = <

                MX6QDL_PAD_SD3_CMD__SD3_CMD        0x17059

                MX6QDL_PAD_SD3_CLK__SD3_CLK        0x10059

                MX6QDL_PAD_SD3_DAT0__SD3_DATA0        0x17059

                MX6QDL_PAD_SD3_DAT1__SD3_DATA1        0x17059

                MX6QDL_PAD_SD3_DAT2__SD3_DATA2        0x17059

                MX6QDL_PAD_SD3_DAT3__SD3_DATA3        0x17059

            

            >;

        };

&iomuxc {

    pinctrl-names = "default";

    pinctrl-0 = <&pinctrl_hog>;

    imx6qdl-sabresd {

        pinctrl_hog: hoggrp {

            fsl,pins = <

                MX6QDL_PAD_NANDF_D0__GPIO2_IO00 0x80000000  /*microsd cd pin*/

};

2.配置文件fstab.freescale usdhc3的地址为2198000

--- a/device/fsl/xxx_6q/fstab.freescale

+++ b/device/fsl/xxx_6q/fstab.freescale

@@ -3,7 +3,7 @@

 # The filesystem that contains the filesystem checker binary (typically /system) cannot

 # specify MF_CHECK, and must come before any filesystems that do specify MF_CHECK

 

-/devices/soc0/soc/2100000.aips-bus/219c000.usdhc/mmc_host* auto auto defaults voldmanaged=sdcard:auto,encrypt

+/devices/soc0/soc/2100000.aips-bus/2198000.usdhc/mmc_host* auto auto defaults voldmanaged=sdcard:auto,encrypt

3.android读写外置sd卡权限配置

文件管理器在保存时出现:外置存储卡写权限被禁止 ,请在保存文件时赋予写权限操作.

--- a/frameworks/base/data/etc/platform.xml

+++ b/frameworks/base/data/etc/platform.xml

@@ -123,7 +123,9 @@

          the fragility as one can remove a built-in permission which

          no longer needs to be mapped to gids and break grant propagation. -->

     <permission name="android.permission.READ_EXTERNAL_STORAGE" />

-    <permission name="android.permission.WRITE_EXTERNAL_STORAGE" />

+       <permission name="android.permission.WRITE_EXTERNAL_STORAGE">

+       <group gid="sdcard_r"/>

+       <group gid="meida_rw"/>