linux/Documentation/devicetree/bindings/mfd/syscon.txt
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   1* System Controller Registers R/W driver
   2
   3System controller node represents a register region containing a set
   4of miscellaneous registers. The registers are not cohesive enough to
   5represent as any specific type of device. The typical use-case is for
   6some other node's driver, or platform-specific code, to acquire a
   7reference to the syscon node (e.g. by phandle, node path, or search
   8using a specific compatible value), interrogate the node (or associated
   9OS driver) to determine the location of the registers, and access the
  10registers directly.
  11
  12Required properties:
  13- compatible: Should contain "syscon".
  14- reg: the register region can be accessed from syscon
  15
  16Examples:
  17gpr: iomuxc-gpr@020e0000 {
  18        compatible = "fsl,imx6q-iomuxc-gpr", "syscon";
  19        reg = <0x020e0000 0x38>;
  20};
  21