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

joaopeixoto
2026-01-07T16:29:40Z

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