[PATCH v5 3/7] dt-bindings: ptp: Add amazon,vmclock

Chalios, Babis
2026-01-07T13:27:18Z

The vmclock device provides a PTP clock source and precise timekeeping
across live migration and snapshot/restore operations.

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

The full spec is at https://uapi-group.org/specifications/specs/vmclock/

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Babis Chalios <bchalios@amazon.es>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
---
.../bindings/ptp/amazon,vmclock.yaml | 46 +++++++++++++++++++
MAINTAINERS | 1 +
2 files changed, 47 insertions(+)
create mode 100644 Documentation/devicetree/bindings/ptp/amazon,vmclock.yaml

diff --git a/Documentation/devicetree/bindings/ptp/amazon,vmclock.yaml b/Documentation/devicetree/bindings/ptp/amazon,vmclock.yaml
new file mode 100644
index 000000000000..357790df876f
--- /dev/null
+++ b/Documentation/devicetree/bindings/ptp/amazon,vmclock.yaml
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/ptp/amazon,vmclock.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Virtual Machine Clock
+
+maintainers:
+ - David Woodhouse <dwmw2@infradead.org>
+
+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://uapi-group.org/specifications/specs/vmclock/
+
+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>
+ ptp@80000000 {
+ compatible = "amazon,vmclock";
+ reg = <0x80000000 0x1000>;
+ interrupts = <GIC_SPI 36 IRQ_TYPE_EDGE_RISING>;
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index e8f06145fb54..171813ea76a3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20728,6 +20728,7 @@ PTP VMCLOCK SUPPORT
M: David Woodhouse <dwmw2@infradead.org>
L: netdev@vger.kernel.org
S: Maintained
+F: Documentation/devicetree/bindings/ptp/amazon,vmclock.yaml
F: drivers/ptp/ptp_vmclock.c
F: include/uapi/linux/vmclock-abi.h

--
2.34.1