as interrupt source (as implied by the gpio-keys driver)
is not possible unless UART0 has been turned off. The later one though
is a rather bad idea as the Routerboard is an embedded device with
only a single serial port, so it's almost always used as serial
console device.

This patch adds a driver based on INPUT_POLLDEV, which disables the
UART and reconfigures GPIO pin 1 temporarily while reading the button
state.  This procedure works fine and has been tested as part of
another, unpublished driver for this device.

Signed-off-by: Phil Sutter <n0-1@freewrt.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
—Žu=“)x