100 lines
3.3 KiB
Plaintext
100 lines
3.3 KiB
Plaintext
* ARM Generic Interrupt Controller
|
|
|
|
ARM SMP cores are often associated with a GIC, providing per processor
|
|
interrupts (PPI), shared processor interrupts (SPI) and software
|
|
generated interrupts (SGI).
|
|
|
|
Primary GIC is attached directly to the CPU and typically has PPIs and SGIs.
|
|
Secondary GICs are cascaded into the upward interrupt controller and do not
|
|
have PPIs or SGIs.
|
|
|
|
Main node required properties:
|
|
|
|
- compatible : should be one of:
|
|
"arm,gic-400"
|
|
"arm,cortex-a15-gic"
|
|
"arm,cortex-a9-gic"
|
|
"arm,cortex-a7-gic"
|
|
"arm,arm11mp-gic"
|
|
"brcm,brahma-b15-gic"
|
|
"qcom,msm-qgic2"
|
|
- interrupt-controller : Identifies the node as an interrupt controller
|
|
- #interrupt-cells : Specifies the number of cells needed to encode an
|
|
interrupt source. The type shall be a <u32> and the value shall be 3.
|
|
|
|
The 1st cell is the interrupt type; 0 for SPI interrupts, 1 for PPI
|
|
interrupts.
|
|
|
|
The 2nd cell contains the interrupt number for the interrupt type.
|
|
SPI interrupts are in the range [0-987]. PPI interrupts are in the
|
|
range [0-15].
|
|
|
|
The 3rd cell is the flags, encoded as follows:
|
|
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
|
|
bits[15:8] PPI interrupt cpu mask. Each bit corresponds to each of
|
|
the 8 possible cpus attached to the GIC. A bit set to '1' indicated
|
|
the interrupt is wired to that CPU. Only valid for PPI interrupts.
|
|
|
|
- reg : Specifies base physical address(s) and size of the GIC registers. The
|
|
first region is the GIC distributor register base and size. The 2nd region is
|
|
the GIC cpu interface register base and size.
|
|
|
|
Optional
|
|
- interrupts : Interrupt source of the parent interrupt controller on
|
|
secondary GICs, or VGIC maintenance interrupt on primary GIC (see
|
|
below).
|
|
|
|
- cpu-offset : per-cpu offset within the distributor and cpu interface
|
|
regions, used when the GIC doesn't have banked registers. The offset is
|
|
cpu-offset * cpu-nr.
|
|
|
|
- arm,routable-irqs : Total number of gic irq inputs which are not directly
|
|
connected from the peripherals, but are routed dynamically
|
|
by a crossbar/multiplexer preceding the GIC. The GIC irq
|
|
input line is assigned dynamically when the corresponding
|
|
peripheral's crossbar line is mapped.
|
|
Example:
|
|
|
|
intc: interrupt-controller@fff11000 {
|
|
compatible = "arm,cortex-a9-gic";
|
|
#interrupt-cells = <3>;
|
|
#address-cells = <1>;
|
|
interrupt-controller;
|
|
arm,routable-irqs = <160>;
|
|
reg = <0xfff11000 0x1000>,
|
|
<0xfff10100 0x100>;
|
|
};
|
|
|
|
|
|
* GIC virtualization extensions (VGIC)
|
|
|
|
For ARM cores that support the virtualization extensions, additional
|
|
properties must be described (they only exist if the GIC is the
|
|
primary interrupt controller).
|
|
|
|
Required properties:
|
|
|
|
- reg : Additional regions specifying the base physical address and
|
|
size of the VGIC registers. The first additional region is the GIC
|
|
virtual interface control register base and size. The 2nd additional
|
|
region is the GIC virtual cpu interface register base and size.
|
|
|
|
- interrupts : VGIC maintenance interrupt.
|
|
|
|
Example:
|
|
|
|
interrupt-controller@2c001000 {
|
|
compatible = "arm,cortex-a15-gic";
|
|
#interrupt-cells = <3>;
|
|
interrupt-controller;
|
|
reg = <0x2c001000 0x1000>,
|
|
<0x2c002000 0x1000>,
|
|
<0x2c004000 0x2000>,
|
|
<0x2c006000 0x2000>;
|
|
interrupts = <1 9 0xf04>;
|
|
};
|