[PATCH 5/5] DT: arm,gic-v3: Documment PPI partition support

From: Marc Zyngier
Date: Mon Apr 11 2016 - 04:58:36 EST


Add a decription of the PPI partitioning support.

Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
.../bindings/interrupt-controller/arm,gic-v3.txt | 34 ++++++++++++++++++++--
1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
index 007a5b4..4c29cda 100644
--- a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
+++ b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
@@ -11,6 +11,8 @@ Main node required properties:
- 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.
+ If the system requires describing PPI affinity, then the value must
+ be at least 4.

The 1st cell is the interrupt type; 0 for SPI interrupts, 1 for PPI
interrupts. Other values are reserved for future use.
@@ -24,7 +26,14 @@ Main node required properties:
1 = edge triggered
4 = level triggered

- Cells 4 and beyond are reserved for future use and must have a value
+ The 4th cell is a phandle to a node describing a set of CPUs this
+ interrupt is affine to. The interrupt must be a PPI, and the node
+ pointed must be a subnode of the "ppi-partitions" subnode. For
+ interrupt types other than PPI or PPIs that are not partitionned,
+ this cell must be zero. See the "ppi-partitions" node description
+ below.
+
+ Cells 5 and beyond are reserved for future use and must have a value
of 0 if present.

- reg : Specifies base physical address(s) and size of the GIC
@@ -50,6 +59,11 @@ Optional

Sub-nodes:

+PPI affinity can be expressed as a single "ppi-partitions" node,
+containing a set of sub-nodes, each with the following property:
+- affinity: Should be a list of phandles to CPU nodes (as described in
+Documentation/devicetree/bindings/arm/cpus.txt).
+
GICv3 has one or more Interrupt Translation Services (ITS) that are
used to route Message Signalled Interrupts (MSI) to the CPUs.

@@ -91,7 +105,7 @@ Examples:

gic: interrupt-controller@2c010000 {
compatible = "arm,gic-v3";
- #interrupt-cells = <3>;
+ #interrupt-cells = <4>;
#address-cells = <2>;
#size-cells = <2>;
ranges;
@@ -119,4 +133,20 @@ Examples:
#msi-cells = <1>;
reg = <0x0 0x2c400000 0 0x200000>;
};
+
+ ppi-partitions {
+ part0: interrupt-partition-0 {
+ affinity = <&cpu0 &cpu2>;
+ };
+
+ part1: interrupt-partition-1 {
+ affinity = <&cpu1 &cpu3>;
+ };
+ };
+ };
+
+
+ device@0 {
+ reg = <0 0 0 4>;
+ interrupts = <1 1 4 &part0>;
};
--
2.1.4