在树莓派4中用引脚控制关机，不起作用

[hyzgit]

直接断电很容易出问题，每次ssh连接用命令关机又很麻烦，在树莓派官方系统中，只要在/boot/config中增加"dtoverlay=gpio-shutdown,gpio_pin=3",即可用此引脚执行关机，但是在openwrt中不起作用，有什么办法可以让它起作用吗？

`Name: gpio-shutdown Info: Initiates a shutdown when GPIO pin changes. The given GPIO pin is configured as an input key that generates KEY_POWER events.

    This event is handled by systemd-logind by initiating a
    shutdown. Systemd versions older than 225 need an udev rule
    enable listening to the input device:

            ACTION!="REMOVE", SUBSYSTEM=="input", KERNEL=="event*", \
                    SUBSYSTEMS=="platform", DRIVERS=="gpio-keys", \
                    ATTRS{keys}=="116", TAG+="power-switch"

    Alternatively this event can be handled also on systems without
    systemd, just by traditional SysV init daemon. KEY_POWER event
    (keycode 116) needs to be mapped to KeyboardSignal on console
    and then kb::kbrequest inittab action which is triggered by
    KeyboardSignal from console can be configured to issue system
    shutdown. Steps for this configuration are:

        Add following lines to the /etc/console-setup/remap.inc file:

            # Key Power as special keypress
            keycode 116 = KeyboardSignal

        Then add following lines to /etc/inittab file:

            # Action on special keypress (Key Power)
            kb::kbrequest:/sbin/shutdown -t1 -a -h -P now

        And finally reload configuration by calling following commands:

            # dpkg-reconfigure console-setup
            # service console-setup reload
            # init q
    This overlay only handles shutdown. After shutdown, the system
    can be powered up again by driving GPIO3 low. The default
    configuration uses GPIO3 with a pullup, so if you connect a
    button between GPIO3 and GND (pin 5 and 6 on the 40-pin header),
    you get a shutdown and power-up button. Please note that
    Raspberry Pi 1 Model B rev 1 uses GPIO1 instead of GPIO3.

Load: dtoverlay=gpio-shutdown,= Params: gpio_pin GPIO pin to trigger on (default 3) For Raspberry Pi 1 Model B rev 1 set this explicitly to value 1, e.g.:

                                dtoverlay=gpio-shutdown,gpio_pin=1

    active_low              When this is 1 (active low), a falling
                            edge generates a key down event and a
                            rising edge generates a key up event.
                            When this is 0 (active high), this is
                            reversed. The default is 1 (active low).

    gpio_pull               Desired pull-up/down state (off, down, up)
                            Default is "up".

                            Note that the default pin (GPIO3) has an
                            external pullup. Same applies for GPIO1
                            on Raspberry Pi 1 Model B rev 1.

    debounce                Specify the debounce interval in milliseconds
                            (default 100)

`

还有下面这个，是很实用的功能

`Name: gpio-poweroff Info: Drives a GPIO high or low on poweroff (including halt). Enabling this overlay will prevent the ability to boot by driving GPIO3 low. Load: dtoverlay=gpio-poweroff,= Params: gpiopin GPIO for signalling (default 26)

    active_low              Set if the power control device requires a
                            high->low transition to trigger a power-down.
                            Note that this will require the support of a
                            custom dt-blob.bin to prevent a power-down
                            during the boot process, and that a reboot
                            will also cause the pin to go low.
    input                   Set if the gpio pin should be configured as
                            an input.
    export                  Set to export the configured pin to sysfs
    timeout_ms              Specify (in ms) how long the kernel waits for
                            power-down before issuing a WARN (default 3000).`

[acooler15]

How to make gpio-shutdown overlay work?安装kmod-gpio-button-hotplug试试

[hyzgit]

How to make gpio-shutdown overlay work?安装kmod-gpio-button-hotplug试试

谢谢，装上这个后，gpio-shutdown功能可以正常使用了，另一个gpio-poweroff，还是不能用，不知道有没有知道怎么解决这个问题。

[acooler15]

How to make gpio-shutdown overlay work?安装kmod-gpio-button-hotplug试试

谢谢，装上这个后，gpio-shutdown功能可以正常使用了，另一个gpio-poweroff，还是不能用，不知道有没有知道怎么解决这个问题。

弱弱的问下，gpio-powroff一般是用来干嘛的？

[hyzgit]

How to make gpio-shutdown overlay work?安装kmod-gpio-button-hotplug试试

谢谢，装上这个后，gpio-shutdown功能可以正常使用了，另一个gpio-poweroff，还是不能用，不知道有没有知道怎么解决这个问题。

弱弱的问下，gpio-powroff一般是用来干嘛的？

可以指示树莓派的开关机状态，比如开机后引脚低电平，关机后变成高电平。