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支持热插拔
需要确认如下&mmc1节点中一定不能有non-removable这个属性节点。
/kernel-3.18/arch/arm64/boot/dts/Project_Name.dts

 &mmc1 {        clk_src = /bits/ 8 ;        bus-width = ;        max-frequency = ;        msdc-sys-suspend;        cap-sd-highspeed;        sd-uhs-sdr12;        sd-uhs-sdr25;        sd-uhs-sdr50;        sd-uhs-sdr104;        sd-uhs-ddr50;        pinctl = <&mmc1_pins_default>;        pinctl_sdr104 = <&mmc1_pins_sdr104>;        pinctl_sdr50 = <&mmc1_pins_sdr50>;        pinctl_ddr50 = <&mmc1_pins_ddr50>;        register_setting = <&mmc1_register_setting_default>;        host_function = /bits/ 8 ;        cd_level = /bits/ 8 ;        cd-gpios = <&pio 5 0>;        /*non-removable;*/        status = "okay";};二、请确认插入和拔出sdcard中断Pin状态

未插入sdcard和插入sdcard的时候相比，中断Pin的电压状态是否有高低变化，如没有变化，请硬件人员检查硬件。
检查中断Pin在拉高的状态下，电压高度是否满足设计要求，例如拉高状态中断Pin电压应为1.8V，实际测量是否可以达到1.8V
1、未插卡中断Pin是高电平，插入卡中断Pin是低电平
cd_level = /bits/ 8 <MSDC_CD_LOW>;

2、未插卡中断Pin是低电平，插入卡中断Pin是高电平
cd_level = /bits/ 8 <MSDC_CD_HIGH>

来源：https://www.cnblogs.com/chjgongzuo/p/11577537.html

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