[PATCH v4 3/9] dt-bindings: mfd: add support for mule

[Farouk Bouabid <farouk.bouabid@cherry.de>]

Mule is an MCU that emulates a set of I2C devices, among which an amc6821
device and an I2C mux that exposes more emulated devices. These two devices
share the same I2C address. Only the I2C mux uses register (0xff) as a
config register.

Add dt-binding support for the Mule I2C multi-function device.

Signed-off-by: Farouk Bouabid <farouk.bouabid@cherry.de>
---
 .../devicetree/bindings/i2c/tsd,mule-i2c-mux.yaml  | 48 +++++++++++++
 .../devicetree/bindings/mfd/tsd,mule.yaml          | 82 ++++++++++++++++++++++
 2 files changed, 130 insertions(+)

diff --git a/Documentation/devicetree/bindings/i2c/tsd,mule-i2c-mux.yaml b/Documentation/devicetree/bindings/i2c/tsd,mule-i2c-mux.yaml
new file mode 100644
index 000000000000..ac9dfc936272
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/tsd,mule-i2c-mux.yaml
@@ -0,0 +1,48 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i2c/tsd,mule-i2c-mux.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Mule I2C multiplexer
+
+maintainers:
+  - Farouk Bouabid <farouk.bouabid@cherry.de>
+  - Quentin Schulz <quentin.schulz@cherry.de>
+
+description: |
+  This module is part of the Mule I2C multi-function device. For more
+  details see ../mfd/tsd,mule.yaml.
+
+  Mule I2C-mux configures the active device that can be accessed on address
+  0x6f through the config register.
+
+      +--------------------------------------------------+
+      | Mule                                             |
+  0x18|    +---------------+                             |
+  -------->|Config register|----+                        |
+      |    +---------------+    |                        |
+      |                         V_                       |
+      |                        |  \          +--------+  |
+      |                        |   \-------->| dev #0 |  |
+      |                        |   |         +--------+  |
+  0x6f|                        | M |-------->| dev #1 |  |
+  ---------------------------->| U |         +--------+  |
+      |                        | X |-------->| dev #2 |  |
+      |                        |   |         +--------+  |
+      |                        |   /-------->| dev #3 |  |
+      |                        |__/          +--------+  |
+      +--------------------------------------------------+
+
+
+allOf:
+  - $ref: /schemas/i2c/i2c-mux.yaml#
+
+properties:
+  compatible:
+    const: tsd,mule-i2c-mux
+
+required:
+  - compatible
+
+unevaluatedProperties: false
diff --git a/Documentation/devicetree/bindings/mfd/tsd,mule.yaml b/Documentation/devicetree/bindings/mfd/tsd,mule.yaml
new file mode 100644
index 000000000000..ab532340a17c
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/tsd,mule.yaml
@@ -0,0 +1,82 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/tsd,mule.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Mule I2C multi function device
+
+maintainers:
+  - Farouk Bouabid <farouk.bouabid@cherry.de>
+  - Quentin Schulz <quentin.schulz@cherry.de>
+
+description:
+  Mule is an MCU that emulates a set of I2C devices, among which an amc6821
+  device and an I2C mux that exposes more emulated devices. These two devices
+  share the same I2C address. Only the I2C mux uses register (0xff) as a config
+  register.
+
+properties:
+  compatible:
+    const: tsd,mule
+
+  reg:
+    maxItems: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+patternProperties:
+  "^fan(@[0-9a-f]+)?$":
+    $ref: /schemas/trivial-devices.yaml
+
+  "^i2c-mux(@[0-9a-f]+)?$":
+    $ref: /schemas/i2c/tsd,mule-i2c-mux.yaml
+
+required:
+  - "#address-cells"
+  - "#size-cells"
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        mule@18 {
+            compatible = "tsd,mule";
+            reg = <0x18>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            fan@18 {
+                compatible = "ti,amc6821";
+                reg = <0x18>;
+            };
+
+            i2c-mux {
+                compatible = "tsd,mule-i2c-mux";
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                i2c@0 {
+                    reg = <0x0>;
+                    #address-cells = <1>;
+                    #size-cells = <0>;
+
+                    rtc@6f {
+                        compatible = "isil,isl1208";
+                        reg = <0x6f>;
+                    };
+                };
+            };
+        };
+    };
+...

-- 
2.34.1