[PATCH v2 3/4] dt-bindings: clock: Add device tree bindings for vmclock

[Chalios, Babis]

From: David Woodhouse <dwmw@xxxxxxxxxxxx>

Add device tree bindings for the vmclock device, similar to the existing
vmgenid bindings. The vmclock device provides a PTP clock source and
precise timekeeping across live migration and snapshot/restore operations.

The bindings specify a required memory region containing the vmclock_abi
structure and an optional interrupt for clock disruption notifications.

Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
Signed-off-by: Babis Chalios <bchalios@xxxxxxxxx>
---
 .../bindings/clock/amazon,vmclock.yaml        | 46 +++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/amazon,vmclock.yaml

diff --git a/Documentation/devicetree/bindings/clock/amazon,vmclock.yaml b/Documentation/devicetree/bindings/clock/amazon,vmclock.yaml
new file mode 100644
index 000000000000..f7dfa022bf6f
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/amazon,vmclock.yaml
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/amazon,vmclock.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Virtual Machine Clock
+
+maintainers:
+  - David Woodhouse <dwmw2@xxxxxxxxxxxxx>
+
+description:
+  The vmclock device provides a precise clock source and allows for
+  accurate timekeeping across live migration and snapshot/restore
+  operations. The full specification of the shared data structure
+  is available at https://david.woodhou.se/VMClock.pdf
+
+properties:
+  compatible:
+    const: amazon,vmclock
+
+  reg:
+    description:
+      Specifies the shared memory region containing the vmclock_abi structure.
+    maxItems: 1
+
+  interrupts:
+    description:
+      Interrupt used to notify when the contents of the vmclock_abi structure
+      have been updated.
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    vmclock@80000000 {
+      compatible = "amazon,vmclock";
+      reg = <0x80000000 0x1000>;
+      interrupts = <GIC_SPI 36 IRQ_TYPE_EDGE_RISING>;
+    };
-- 
2.34.1