xref: /freebsd/sys/contrib/device-tree/Bindings/gpio/ibm,ppc4xx-gpio.txt (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)
1* IBM/AMCC/APM GPIO Controller for PowerPC 4XX series and compatible SoCs
2
3All GPIOs are pin-shared with other functions. DCRs control whether a
4particular pin that has GPIO capabilities acts as a GPIO or is used for
5another purpose. GPIO outputs are separately programmable to emulate
6an open-drain driver.
7
8Required properties:
9	- compatible: must be "ibm,ppc4xx-gpio"
10	- reg: address and length of the register set for the device
11	- #gpio-cells: must be set to 2. The first cell is the pin number
12		and the second cell is used to specify the gpio polarity:
13		0 = active high
14		1 = active low
15	- gpio-controller: marks the device node as a gpio controller.
16
17Example:
18
19GPIO0: gpio@ef600b00 {
20	compatible = "ibm,ppc4xx-gpio";
21	reg = <0xef600b00 0x00000048>;
22	#gpio-cells = <2>;
23	gpio-controller;
24};
25