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From: Sudan Landge <sudanl@amazon.com>
To: <tytso@mit.edu>, <Jason@zx2c4.com>, <robh+dt@kernel.org>,
	<krzysztof.kozlowski+dt@linaro.org>, <conor+dt@kernel.org>,
	<sudanl@amazon.com>, <sathyanarayanan.kuppuswamy@linux.intel.com>,
	<thomas.lendacky@amd.com>, <dan.j.williams@intel.com>,
	<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
CC: <graf@amazon.de>, <dwmw@amazon.co.uk>, <bchalios@amazon.es>,
	<xmarcalx@amazon.co.uk>
Subject: [PATCH v1 3/4] dt-bindings: Add bindings for vmgenid
Date: Tue, 19 Mar 2024 14:32:52 +0000
Message-ID: <20240319143253.22317-4-sudanl@amazon.com>
In-Reply-To: <20240319143253.22317-1-sudanl@amazon.com>
References: <20240319143253.22317-1-sudanl@amazon.com>
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Virtual Machine Generation ID driver was introduced in commit af6b54e2b5ba
("virt: vmgenid: notify RNG of VM fork and supply generation ID"), as an
ACPI only device.

Add a devicetree binding support for vmgenid so that hypervisors
can support vmgenid without the need to support ACPI.

Signed-off-by: Sudan Landge <sudanl@amazon.com>
---
 .../devicetree/bindings/vmgenid/vmgenid.yaml  | 57 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 58 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/vmgenid/vmgenid.yaml

diff --git a/Documentation/devicetree/bindings/vmgenid/vmgenid.yaml b/Documentation/devicetree/bindings/vmgenid/vmgenid.yaml
new file mode 100644
index 000000000000..17773aa96f8b
--- /dev/null
+++ b/Documentation/devicetree/bindings/vmgenid/vmgenid.yaml
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/vmgenid/vmgenid.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Virtual Machine Generation Counter ID device.
+
+maintainers:
+  - Jason A. Donenfeld <Jason@zx2c4.com>
+
+description: |+
+  Firmwares or hypervisors can use this devicetree to describe
+  interrupts and the shared resources to inject a Virtual Machine Generation
+  counter.
+
+properties:
+  compatible:
+    const: linux,vmgenctr
+
+  "#interrupt-cells":
+    const: 3
+    description: |
+      The 1st cell is the interrupt type.
+      The 2nd cell contains the interrupt number for the interrupt type.
+      The 3rd cell is for trigger type and level flags.
+
+  interrupt-controller: true
+
+  reg:
+    description: |
+      specifies the base physical address and
+      size of the regions in memory which holds the VMGenID counter.
+    maxItems: 1
+
+  interrupts:
+    description: |
+      interrupt used to notify that a new VMGenID counter is available.
+      The interrupt should be Edge triggered.
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    vmgenid@80000000 {
+      compatible = "linux,vmgenctr";
+      reg = <0x80000000 0x1000>;
+      interrupts = <0x00 0x23 0x01>;
+    };
+
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index d818866d6d73..e602a51b9bd7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18359,6 +18359,7 @@ M:	"Theodore Ts'o" <tytso@mit.edu>
 M:	Jason A. Donenfeld <Jason@zx2c4.com>
 S:	Maintained
 T:	git https://git.kernel.org/pub/scm/linux/kernel/git/crng/random.git
+F:	Documentation/devicetree/bindings/vmgenid/vmgenid.yaml
 F:	drivers/char/random.c
 F:	drivers/virt/vmgenid.c
 
-- 
2.40.1