dt-bindings: ipmi: Add binding for IPMB device

Add device tree binding document for the IPMB device interface.
This device is already in use in both driver and .dts files.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Ninad Palsule <ninad@linux.ibm.com>
Acked-by: Corey Minyard <corey@minyard.net>
Link: https://patch.msgid.link/20250204194115.3899174-2-ninad@linux.ibm.com
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>

1 files changed, 56 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/ipmi/ipmb-dev.yaml b/Documentation/devicetree/bindings/ipmi/ipmb-dev.yaml
new file mode 100644
index 000000000000..8b0d71901195
--- /dev/null
+++ b/Documentation/devicetree/bindings/ipmi/ipmb-dev.yaml
@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/ipmi/ipmb-dev.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: The Intelligent Platform Management Bus(IPMB) Device
+
+description: |
+  The IPMB is an I2C bus which provides interconnection between a Baseboard
+  Management Controller(BMC) and chassis electronics. The BMC sends IPMI
+  requests to intelligent controllers like Satellite Management Controller(MC)
+  devices via IPMB and the device sends responses back to the BMC.
+  This device uses an I2C slave device to send and receive IPMB messages,
+  either on a BMC or other MC. A miscellaneous device provices a user space
+  program to communicate with the kernel and the backend device. Some IPMB
+  devices only support the I2C protocol and not the SMB protocol.
+
+  IPMB communications protocol Specification V1.0
+  https://www.intel.com/content/dam/www/public/us/en/documents/product-briefs/ipmp-spec-v1.0.pdf
+
+maintainers:
+  - Ninad Palsule <ninad@linux.ibm.com>
+
+properties:
+  compatible:
+    enum:
+      - ipmb-dev
+
+  reg:
+    maxItems: 1
+
+  i2c-protocol:
+    description:
+      Use I2C block transfer instead of SMBUS block transfer.
+    type: boolean
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/i2c/i2c.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        ipmb-dev@10 {
+            compatible = "ipmb-dev";
+            reg = <(0x10 | I2C_OWN_SLAVE_ADDRESS)>;
+            i2c-protocol;
+        };
+    };