I'm trying to understand the device tree interrupts
property and can not find a good explanation.
For example if there is a node with the following lines:
interrupt-parent = <&gpio5>;
interrupts = <9 0>;
How do I figure out what the magic numbers <9 0>
relate to?
Is it a bitmask, gpio port number, pin number, priority, edge or something else?
Theinterrupt-parent
node look like this (I guess it would be similar for most ARM devices):
gpio5: gpio@1234 {
compatible = "fsl,imx7d-gpio", "fsl,imx35-gpio";
reg = <0x30240000 0x10000>;
interrupts = <GIC_SPI 72 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 73 IRQ_TYPE_LEVEL_HIGH>;
gpio-controller;
#gpio-cells = <2>;
interrupt-controller;
#interrupt-cells = <2>;
};
Best Answer
You can get some information from the kernel documentation which describes the interrupts property.
It goes on with the example of the OpenPIC interrupt controller which has 2 cells:
Your case is probably similar, but it often needs you to have intimate knowledge of the chipset and the driver.