APM X-Gene Standby GPIO controller bindings
This is a gpio controller in the standby domain. It also supports interrupt in
some particular pins which are sourced to its parent interrupt controller
as diagram below:
+—————–+
| X-Gene standby |
| GPIO controller +—— GPIO_0
+————+ | | …
| Parent IRQ | EXT_INT_0 | +—— GPIO_8/EXT_INT_0
| controller | (SPI40) | | …
| (GICv2) +————–+ +—— GPIO_[N+8]/EXT_INT_N
| | … | |
| | EXT_INT_N | +—— GPIO_[N+9]
| | (SPI[40 + N])| | …
| +————–+ +—— GPIO_MAX
+————+ +—————–+
Required properties:
- compatible: “apm,xgene-gpio-sb” for the X-Gene Standby GPIO controller
- reg: Physical base address and size of the controller’s registers
- #gpio-cells: Should be two.
- first cell is the pin number
- second cell is used to specify the gpio polarity:
0 = active high
1 = active low
- gpio-controller: Marks the device node as a GPIO controller.
- interrupts: The EXT_INT_0 parent interrupt resource must be listed first.
- interrupt-parent: Phandle of the parent interrupt controller.
- interrupt-cells: Should be two.
- first cell is 0-N coresponding for EXT_INT_0 to EXT_INT_N. - second cell is used to specify flags. - interrupt-controller: Marks the device node as an interrupt controller.
- apm,nr-gpios: Optional, specify number of gpios pin.
- apm,nr-irqs: Optional, specify number of interrupt pins.
- apm,irq-start: Optional, specify lowest gpio pin support interrupt.
Example:
sbgpio: gpio@17001000{
compatible = “apm,xgene-gpio-sb”;
reg = <0x0 0x17001000 0x0 0x400>;
#gpio-cells = <2>;
gpio-controller;
interrupts = <0x0 0x28 0x1>,
<0x0 0x29 0x1>,
<0x0 0x2a 0x1>,
<0x0 0x2b 0x1>,
<0x0 0x2c 0x1>,
<0x0 0x2d 0x1>;
interrupt-parent = <&gic>;
#interrupt-cells = <2>;
interrupt-controller;
apm,nr-gpios = <22>;
apm,nr-irqs = <6>;
apm,irq-start = <8>;
};
testuser {
compatible = "example,testuser";
/* Use the GPIO_13/EXT_INT_5 line as an active high triggered
* level interrupt
*/
interrupts = <5 4>;
interrupt-parent = <&sbgpio>;
};
