[PATCH 2/7] dt-bindings: i2c: mux: mule: add dt-bindings for mule i2c multiplexer

[Farouk Bouabid <farouk.bouabid@theobroma-systems.com>]

This patch adds support for the Mule I2C multiplexer.

Mule is an mcu that emulates a set of i2c devices which are reacheable
through an i2c-mux.

The emulated devices share a single i2c address with the mux itself where
the requested register is what determines which logic is executed (mux or
device).

Signed-off-by: Farouk Bouabid <farouk.bouabid@theobroma-systems.com>
---
 .../devicetree/bindings/i2c/i2c-mux-mule.yaml      | 80 ++++++++++++++++++++++
 1 file changed, 80 insertions(+)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-mule.yaml b/Documentation/devicetree/bindings/i2c/i2c-mux-mule.yaml
new file mode 100644
index 000000000000..458e4661cbc8
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-mux-mule.yaml
@@ -0,0 +1,80 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i2c/i2c-mux-mule.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Mule I2C multiplexer
+
+maintainers:
+  - Farouk Bouabid <farouk.bouabid@theobroma-systems.com>
+  - Quentin Schulz <quentin.schulz@theobroma-systems.com>
+
+description: |
+  Mule is an mcu that emulates a set of i2c devices which are reacheable
+  through an i2c-mux.
+
+  The emulated devices share a single i2c address with the mux itself where
+  the requested register is what determines which logic is executed (mux or
+  device)
+
+      +--------------------------------------------------+
+      | Mule                                             |
+      |    +---------------+                             |
+  ------+->|Config register|----+                        |
+      | |  +---------------+    |                        |
+      | |                       V_                       |
+      | |                      |  \          +--------+  |
+      | |                      |   \-------->| dev #0 |  |
+      | |                      |   |         +--------+  |
+      | |                      | M |-------->| dev #1 |  |
+      | +--------------------->| U |         +--------+  |
+      |                        | X |-------->| dev #2 |  |
+      |                        |   |         +--------+  |
+      |                        |   /-------->| dev #3 |  |
+      |                        |__/          +--------+  |
+      +--------------------------------------------------+
+
+
+allOf:
+  - $ref: /schemas/i2c/i2c-mux.yaml#
+
+properties:
+  compatible:
+    const: tsd,mule-i2c-mux
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        i2c-mux@18 {
+            compatible = "tsd,mule-i2c-mux";
+            reg = <0x18>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            i2c@0 {
+                reg = <0x0>;
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                fan: fan@18 {
+                  compatible = "ti,amc6821";
+                  reg = <0x18>;
+                  #cooling-cells = <2>;
+                };
+            };
+        };
+    };
+...

-- 
2.34.1