linux/Documentation/devicetree/bindings/power_supply/qnap-poweroff.txt
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   1* QNAP Power Off
   2
   3QNAP NAS devices have a microcontroller controlling the main power
   4supply. This microcontroller is connected to UART1 of the Kirkwood and
   5Orion5x SoCs. Sending the character 'A', at 19200 baud, tells the
   6microcontroller to turn the power off. This driver adds a handler to
   7pm_power_off which is called to turn the power off.
   8
   9Required Properties:
  10- compatible: Should be "qnap,power-off"
  11
  12- reg: Address and length of the register set for UART1
  13- clocks: tclk clock
  14