dt-bindings: hwmon: add support for MCP998X

Victor Duicu · groeck · commit a345c1e3cd1b · 2026-04-10T09:21:35.000-07:00
Add devicetree schema for Microchip MCP998X/33 and MCP998XD/33D Multichannel Automotive Temperature Monitor Family. Signed-off-by: Victor Duicu <victor.duicu@microchip.com> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com> Link: https://lore.kernel.org/r/20260403-add-mcp9982-hwmon-v12-1-b3bfb26ff136@microchip.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
diff --git a/Documentation/devicetree/bindings/hwmon/microchip,mcp9982.yaml b/Documentation/devicetree/bindings/hwmon/microchip,mcp9982.yaml
@@ -0,0 +1,237 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/microchip,mcp9982.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip MCP998X/33 and MCP998XD/33D Temperature Monitor
+
+maintainers:
+  - Victor Duicu <victor.duicu@microchip.com>
+
+description: |
+  The MCP998X/33 and MCP998XD/33D family is a high-accuracy 2-wire
+  multichannel automotive temperature monitor.
+  The datasheet can be found here:
+    https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/MCP998X-Family-Data-Sheet-DS20006827.pdf
+
+properties:
+  compatible:
+    enum:
+      - microchip,mcp9933
+      - microchip,mcp9933d
+      - microchip,mcp9982
+      - microchip,mcp9982d
+      - microchip,mcp9983
+      - microchip,mcp9983d
+      - microchip,mcp9984
+      - microchip,mcp9984d
+      - microchip,mcp9985
+      - microchip,mcp9985d
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    minItems: 1
+    maxItems: 2
+
+  interrupt-names:
+    description:
+      The chip family has three different interrupt pins divided among them.
+      The chips without "D" have alert-therm and therm-addr.
+      The chips with "D" have alert-therm and sys-shtdwn.
+    minItems: 1
+    items:
+      - enum: [alert-therm, therm-addr, sys-shtdwn]
+      - enum: [therm-addr, sys-shtdwn]
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  microchip,enable-anti-parallel:
+    description:
+      Enable anti-parallel diode mode operation.
+      MCP9984/84D/85/85D and MCP9933/33D support reading two external diodes
+      in anti-parallel connection on the same set of pins.
+    type: boolean
+
+  microchip,parasitic-res-on-channel1-2:
+    description:
+      Indicates that the chip and the diodes/transistors are sufficiently far
+      apart that a parasitic resistance is added to the wires, which can affect
+      the measurements. Due to the anti-parallel diode connections, channels
+      1 and 2 are affected together.
+    type: boolean
+
+  microchip,parasitic-res-on-channel3-4:
+    description:
+      Indicates that the chip and the diodes/transistors are sufficiently far
+      apart that a parasitic resistance is added to the wires, which can affect
+      the measurements. Due to the anti-parallel diode connections, channels
+      3 and 4 are affected together.
+    type: boolean
+
+  microchip,power-state:
+    description:
+      The chip can be set in Run state or Standby state. In Run state the ADC
+      is converting on all channels at the programmed conversion rate.
+      In Standby state the host must initiate a conversion cycle by writing
+      to the One-Shot register.
+      True value sets Run state.
+      Chips with "D" in the name can only be set in Run mode.
+    type: boolean
+
+  vdd-supply: true
+
+patternProperties:
+  "^channel@[1-4]$":
+    description:
+      Represents the external temperature channels to which
+      a remote diode is connected.
+    type: object
+
+    properties:
+      reg:
+        items:
+          maxItems: 1
+
+      label:
+        description: Unique name to identify which channel this is.
+
+    required:
+      - reg
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - vdd-supply
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - microchip,mcp9982d
+              - microchip,mcp9983d
+              - microchip,mcp9984d
+              - microchip,mcp9985d
+              - microchip,mcp9933d
+    then:
+      properties:
+        interrupt-names:
+          items:
+            enum:
+              - alert-therm
+              - sys-shtdwn
+      required:
+        - microchip,power-state
+        - microchip,parasitic-res-on-channel1-2
+    else:
+      properties:
+        microchip,power-state: true
+        interrupt-names:
+          items:
+            enum:
+              - alert-therm
+              - therm-addr
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - microchip,mcp9983d
+              - microchip,mcp9984d
+              - microchip,mcp9985d
+    then:
+      required:
+        - microchip,parasitic-res-on-channel3-4
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - microchip,mcp9982
+              - microchip,mcp9982d
+    then:
+      properties:
+        microchip,enable-anti-parallel: false
+      patternProperties:
+        "^channel@[2-4]$": false
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - microchip,mcp9983
+              - microchip,mcp9983d
+    then:
+      properties:
+        microchip,enable-anti-parallel: false
+      patternProperties:
+        "^channel@[3-4]$": false
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - microchip,mcp9933
+              - microchip,mcp9933d
+    then:
+      patternProperties:
+        "^channel@[3-4]$": false
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - microchip,mcp9984
+              - microchip,mcp9984d
+    then:
+      properties:
+        channel@4: false
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        temperature-sensor@4c {
+            compatible = "microchip,mcp9985";
+            reg = <0x4c>;
+
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            microchip,enable-anti-parallel;
+            microchip,parasitic-res-on-channel1-2;
+            microchip,parasitic-res-on-channel3-4;
+            vdd-supply = <&vdd>;
+
+            channel@1 {
+                reg = <1>;
+                label = "Room Temperature";
+            };
+
+            channel@2 {
+                reg = <2>;
+                label = "GPU Temperature";
+            };
+        };
+    };
+
+...
diff --git a/MAINTAINERS b/MAINTAINERS
@@ -17358,6 +17358,12 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/iio/adc/microchip,mcp3911.yaml
 F:	drivers/iio/adc/mcp3911.c
 
+MICROCHIP MCP9982 TEMPERATURE DRIVER
+M:	Victor Duicu <victor.duicu@microchip.com>
+L:	linux-hwmon@vger.kernel.org
+S:	Supported
+F:	Documentation/devicetree/bindings/hwmon/microchip,mcp9982.yaml
+
 MICROCHIP MMC/SD/SDIO MCI DRIVER
 M:	Aubin Constans <aubin.constans@microchip.com>
 S:	Maintained
