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+Broadcom BCM2835 GPIO (and pinmux) controller
+
+The BCM2835 GPIO module is a combined GPIO controller, (GPIO) interrupt
+controller, and pinmux/control device.
+
+Required properties:
+- compatible: "brcm,bcm2835-gpio"
+- reg: Should contain the physical address of the GPIO module's registes.
+- gpio-controller: Marks the device node as a GPIO controller.
+- #gpio-cells : Should be two. The first cell is the pin number and the
+ second cell is used to specify optional parameters:
+ - bit 0 specifies polarity (0 for normal, 1 for inverted)
+- interrupts : The interrupt outputs from the controller. One interrupt per
+ individual bank followed by the "all banks" interrupt.
+- interrupt-controller: Marks the device node as an interrupt controller.
+- #interrupt-cells : Should be 2.
+ The first cell is the GPIO number.
+ The second cell is used to specify flags:
+ bits[3:0] trigger type and level flags:
+ 1 = low-to-high edge triggered.
+ 2 = high-to-low edge triggered.
+ 4 = active high level-sensitive.
+ 8 = active low level-sensitive.
+ Valid combinations are 1, 2, 3, 4, 8.
+
+Please refer to ../gpio/gpio.txt for a general description of GPIO bindings.
+
+Please refer to pinctrl-bindings.txt in this directory for details of the
+common pinctrl bindings used by client devices, including the meaning of the
+phrase "pin configuration node".
+
+Each pin configuration node lists the pin(s) to which it applies, and one or
+more of the mux function to select on those pin(s), and pull-up/down
+configuration. Each subnode only affects those parameters that are explicitly
+listed. In other words, a subnode that lists only a mux function implies no
+information about any pull configuration. Similarly, a subnode that lists only
+a pul parameter implies no information about the mux function.
+
+Required subnode-properties:
+- brcm,pins: An array of cells. Each cell contains the ID of a pin. Valid IDs
+ are the integer GPIO IDs; 0==GPIO0, 1==GPIO1, ... 53==GPIO53.
+
+Optional subnode-properties:
+- brcm,function: Integer, containing the function to mux to the pin(s):
+ 0: GPIO in
+ 1: GPIO out
+ 2: alt5
+ 3: alt4
+ 4: alt0
+ 5: alt1
+ 6: alt2
+ 7: alt3
+- brcm,pull: Integer, representing the pull-down/up to apply to the pin(s):
+ 0: none
+ 1: down
+ 2: up
+
+Each of brcm,function and brcm,pull may contain either a single value which
+will be applied to all pins in brcm,pins, or 1 value for each entry in
+brcm,pins.
+
+Example:
+
+ gpio: gpio {
+ compatible = "brcm,bcm2835-gpio";
+ reg = <0x2200000 0xb4>;
+ interrupts = <2 17>, <2 19>, <2 18>, <2 20>;
+
+ gpio-controller;
+ #gpio-cells = <2>;
+
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ };