linux/Documentation/devicetree/bindings/gpio/8xxx_gpio.txt
Grant Likely d524dac927 dt: Move device tree documentation out of powerpc directory
The device tree is used by more than just PowerPC.  Make the documentation
directory available to all.

v2: reorganized files while moving to create arch and driver specific
    directories.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
2011-01-31 00:09:01 -07:00

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GPIO controllers on MPC8xxx SoCs
This is for the non-QE/CPM/GUTs GPIO controllers as found on
8349, 8572, 8610 and compatible.
Every GPIO controller node must have #gpio-cells property defined,
this information will be used to translate gpio-specifiers.
Required properties:
- compatible : "fsl,<CHIP>-gpio" followed by "fsl,mpc8349-gpio" for
83xx, "fsl,mpc8572-gpio" for 85xx and "fsl,mpc8610-gpio" for 86xx.
- #gpio-cells : Should be two. The first cell is the pin number and the
second cell is used to specify optional parameters (currently unused).
- interrupts : Interrupt mapping for GPIO IRQ.
- interrupt-parent : Phandle for the interrupt controller that
services interrupts for this device.
- gpio-controller : Marks the port as GPIO controller.
Example of gpio-controller nodes for a MPC8347 SoC:
gpio1: gpio-controller@c00 {
#gpio-cells = <2>;
compatible = "fsl,mpc8347-gpio", "fsl,mpc8349-gpio";
reg = <0xc00 0x100>;
interrupts = <74 0x8>;
interrupt-parent = <&ipic>;
gpio-controller;
};
gpio2: gpio-controller@d00 {
#gpio-cells = <2>;
compatible = "fsl,mpc8347-gpio", "fsl,mpc8349-gpio";
reg = <0xd00 0x100>;
interrupts = <75 0x8>;
interrupt-parent = <&ipic>;
gpio-controller;
};
See booting-without-of.txt for details of how to specify GPIO
information for devices.
To use GPIO pins as interrupt sources for peripherals, specify the
GPIO controller as the interrupt parent and define GPIO number +
trigger mode using the interrupts property, which is defined like
this:
interrupts = <number trigger>, where:
- number: GPIO pin (0..31)
- trigger: trigger mode:
2 = trigger on falling edge
3 = trigger on both edges
Example of device using this is:
funkyfpga@0 {
compatible = "funky-fpga";
...
interrupts = <4 3>;
interrupt-parent = <&gpio1>;
};