dt-bindings: ptp: Add amazon,vmclock

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>
Tested-by: Takahiro Itazuri <itazur@amazon.com>
Link: https://patch.msgid.link/20260130173704.12575-4-itazur@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/Documentation/devicetree/bindings/ptp/amazon,vmclock.yaml b/Documentation/devicetree/bindings/ptp/amazon,vmclock.yaml
new file mode 100644 (file)
index 0000000..357790d
--- /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 0caa8aee58408cac80e37e31841dc9a971f62212..98b07da905b08f9bb37ad2510045793049d66b96 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21037,6 +21037,7 @@ 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