linux/Documentation/devicetree/bindings/arm/gic-v3.txt
Marc Zyngier b3a92e2c44 irqchip: GICv3: Binding updates for ITS
Add the documentation for the bindings describing the GICv3 ITS.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-14-git-send-email-marc.zyngier@arm.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-11-26 15:55:16 +00:00

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* ARM Generic Interrupt Controller, version 3
AArch64 SMP cores are often associated with a GICv3, providing Private
Peripheral Interrupts (PPI), Shared Peripheral Interrupts (SPI),
Software Generated Interrupts (SGI), and Locality-specific Peripheral
Interrupts (LPI).
Main node required properties:
- compatible : should at least contain "arm,gic-v3".
- interrupt-controller : Identifies the node as an interrupt controller
- #interrupt-cells : Specifies the number of cells needed to encode an
interrupt source. Must be a single cell with a value of at least 3.
The 1st cell is the interrupt type; 0 for SPI interrupts, 1 for PPI
interrupts. Other values are reserved for future use.
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 = edge triggered
4 = level triggered
Cells 4 and beyond are reserved for future use. When the 1st cell
has a value of 0 or 1, cells 4 and beyond act as padding, and may be
ignored. It is recommended that padding cells have a value of 0.
- reg : Specifies base physical address(s) and size of the GIC
registers, in the following order:
- GIC Distributor interface (GICD)
- GIC Redistributors (GICR), one range per redistributor region
- GIC CPU interface (GICC)
- GIC Hypervisor interface (GICH)
- GIC Virtual CPU interface (GICV)
GICC, GICH and GICV are optional.
- interrupts : Interrupt source of the VGIC maintenance interrupt.
Optional
- redistributor-stride : If using padding pages, specifies the stride
of consecutive redistributors. Must be a multiple of 64kB.
- #redistributor-regions: The number of independent contiguous regions
occupied by the redistributors. Required if more than one such
region is present.
Sub-nodes:
GICv3 has one or more Interrupt Translation Services (ITS) that are
used to route Message Signalled Interrupts (MSI) to the CPUs.
These nodes must have the following properties:
- compatible : Should at least contain "arm,gic-v3-its".
- msi-controller : Boolean property. Identifies the node as an MSI controller
- reg: Specifies the base physical address and size of the ITS
registers.
The main GIC node must contain the appropriate #address-cells,
#size-cells and ranges properties for the reg property of all ITS
nodes.
Examples:
gic: interrupt-controller@2cf00000 {
compatible = "arm,gic-v3";
#interrupt-cells = <3>;
#address-cells = <2>;
#size-cells = <2>;
ranges;
interrupt-controller;
reg = <0x0 0x2f000000 0 0x10000>, // GICD
<0x0 0x2f100000 0 0x200000>, // GICR
<0x0 0x2c000000 0 0x2000>, // GICC
<0x0 0x2c010000 0 0x2000>, // GICH
<0x0 0x2c020000 0 0x2000>; // GICV
interrupts = <1 9 4>;
gic-its@2c200000 {
compatible = "arm,gic-v3-its";
msi-controller;
reg = <0x0 0x2c200000 0 0x200000>;
};
};
gic: interrupt-controller@2c010000 {
compatible = "arm,gic-v3";
#interrupt-cells = <3>;
#address-cells = <2>;
#size-cells = <2>;
ranges;
interrupt-controller;
redistributor-stride = <0x0 0x40000>; // 256kB stride
#redistributor-regions = <2>;
reg = <0x0 0x2c010000 0 0x10000>, // GICD
<0x0 0x2d000000 0 0x800000>, // GICR 1: CPUs 0-31
<0x0 0x2e000000 0 0x800000>; // GICR 2: CPUs 32-63
<0x0 0x2c040000 0 0x2000>, // GICC
<0x0 0x2c060000 0 0x2000>, // GICH
<0x0 0x2c080000 0 0x2000>; // GICV
interrupts = <1 9 4>;
gic-its@2c200000 {
compatible = "arm,gic-v3-its";
msi-controller;
reg = <0x0 0x2c200000 0 0x200000>;
};
gic-its@2c400000 {
compatible = "arm,gic-v3-its";
msi-controller;
reg = <0x0 0x2c400000 0 0x200000>;
};
};