Docs: dt: add #msi-cells to GICv3 ITS binding

The GICv3 ITS uses sideband master identification data (known as a
DeviceID) to identify which master wrote to a doorbell, and this data is
used to determine how to react in response to the write.

Commit 1e6db000482fa65a ("irqchip/gicv3-its: Add platform MSI support")
added support per this binding, but failed to update the documentation.
This patch fixes the documentation.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>

diff --git a/Documentation/devicetree/bindings/arm/gic-v3.txt b/Documentation/devicetree/bindings/arm/gic-v3.txt
index ddfade40ac596ca773fd4763d1e3b60b6f42209e..7803e77d85cbe9d69dfcd42405ece4de0ddfe329 100644 (file)
--- a/Documentation/devicetree/bindings/arm/gic-v3.txt
+++ b/Documentation/devicetree/bindings/arm/gic-v3.txt
@@ -57,6 +57,8 @@ 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
+- #msi-cells: Must be <1>. The single msi-cell is the DeviceID of the device
+  which will generate the MSI.
 - reg: Specifies the base physical address and size of the ITS
   registers.
 
@@ -83,6 +85,7 @@ Examples:
                gic-its@2c200000 {
                        compatible = "arm,gic-v3-its";
                        msi-controller;
+                       #msi-cells = <1>;
                        reg = <0x0 0x2c200000 0 0x200000>;
                };
        };
@@ -107,12 +110,14 @@ Examples:
                gic-its@2c200000 {
                        compatible = "arm,gic-v3-its";
                        msi-controller;
+                       #msi-cells = <1>;
                        reg = <0x0 0x2c200000 0 0x200000>;
                };
 
                gic-its@2c400000 {
                        compatible = "arm,gic-v3-its";
                        msi-controller;
+                       #msi-cells = <1>;
                        reg = <0x0 0x2c400000 0 0x200000>;
                };
        };