[PATCH 3/6] dt-bindings: Add Bao I/O dispatcher driver binding

[joaopeixoto@osyx.tech]

From: João Peixoto <joaopeixoto@osyx.tech>

This patch introduces a device tree binding for the Bao I/O Dispatcher,
a device used in backend VMs running virtualized devices (e.g., VirtIO).

Signed-off-by: João Peixoto <joaopeixoto@osyx.tech>
---
 .../bindings/bao/bao,io-dispatcher.yaml       | 75 +++++++++++++++++++
 1 file changed, 75 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bao/bao,io-dispatcher.yaml

diff --git a/Documentation/devicetree/bindings/bao/bao,io-dispatcher.yaml b/Documentation/devicetree/bindings/bao/bao,io-dispatcher.yaml
new file mode 100644
index 000000000000..8ca450e4b9d5
--- /dev/null
+++ b/Documentation/devicetree/bindings/bao/bao,io-dispatcher.yaml
@@ -0,0 +1,75 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/bao/bao,io-dispatcher.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Bao I/O Dispatcher Device
+
+maintainers:
+  - João Peixoto <joaopeixoto@osyx.tech>
+  - José Martins <jose@osyx.tech>
+  - David Cerdeira <davidmcerdeira@osyx.tech>
+
+description: |
+  I/O Dispatcher device for Bao hypervisor guests that run virtualized
+  devices (e.g., VirtIO).
+
+  This device is only required in backend VMs, which are responsible for
+  performing the actual I/O operations on physical hardware. Frontend
+  VMs, which only consume I/O services, do not require this device.
+
+  The I/O Dispatcher provides access to one or more backend devices.
+  Each backend device is associated with a contiguous shared-memory
+  region used to exchange I/O buffers with the respective frontend
+  driver, and an interrupt used by the Bao hypervisor to notify the
+  backend VM of pending I/O requests.
+
+properties:
+  compatible:
+    const: bao,io-dispatcher
+
+  reg:
+    description: |
+      Contiguous memory-mapped regions for each VirtIO backend device
+      managed by the I/O Dispatcher.
+
+      Each region is used to exchange I/O buffers between the backend
+      and frontend devices. A single region corresponds to one
+      backend device.
+    minItems: 1
+    maxItems: 64
+
+  interrupts:
+    description: |
+      Interrupts associated with the VirtIO backend devices.
+
+      Each interrupt corresponds to a backend device and is used
+      by the Bao hypervisor to notify the backend VM of pending
+      I/O requests from the associated frontend driver.
+    minItems: 1
+    maxItems: 64
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    bao-io-dispatcher@50000000 {
+        compatible = "bao,io-dispatcher";
+        reg = <0x0 0x50000000 0x0 0x01000000
+               0x0 0x51000000 0x0 0x01000000
+               0x0 0x52000000 0x0 0x01000000
+               0x0 0x53000000 0x0 0x01000000
+               0x0 0x54000000 0x0 0x01000000>;
+        interrupts = <0x0 0x08 0x1
+                      0x0 0x09 0x1
+                      0x0 0x0a 0x1
+                      0x0 0x0b 0x1
+                      0x0 0x0c 0x1>;
+        interrupt-parent = <&gic>;
+    };
-- 
2.43.0