Merge tag 'mfd-next-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd

Pull mfd updates from Lee Jones:

 - Fix race in device_node_get_regmap() using more extensive locking

 - Remove unused platform driver support for syscon

 - Allow syscon nodes to be registered without a "syscon" compatible
   string

 - Make `platform_data` pointer const in struct mfd_cell

 - Revert support for multiple AXP PMICs to avoid regressions

 - Increase SoundWire attach timeout and use gpiod_set_raw() for GPIO
   operation

 - Store the result from fault_log() for use by other sub-components

 - Fix an invalid regmap-config max_register value

 - Add another Gemini Lake ISA bridge PCI device ID

 - Use devm_register_power_off_handler() to simplify code

 - Add support for QNAP microcontroller units, including LEDs, input,
   and hwmon

 - Use MFD_CELL macros and remove unused code

 - Add support for AAEON UP board FPGA

 - Remove unused includes

 - Fix various typos and compatibility issues in multiple bindings

 - Add new bindings for rk3562 QoS, LED1202, and qcom,tcsr-ipq5424

 - Convert several bindings to YAML schema

 - Update sprd,sc2731 bindings to reference sprd,sc2731-efuse bindings
   directly

 - Fix rohm,bd71815 bindings by correcting resistor values and typos

 - Documentation improvements:
    - Add documentation for LED1202 and qnap-mcu-hwmon
    - Adjust the file entry for the qnap-mcu header in MAINTAINERS

* tag 'mfd-next-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (35 commits)
  MAINTAINERS: Adjust the file entry for the qnap-mcu header
  dt-bindings: mfd: syscon: Fix ti,j784s4-acspcie-proxy-ctrl compatible
  dt-bindings: mfd: syscon: Fix al,alpine-sysfabric-service compatible
  Revert "mfd: axp20x: Allow multiple regulators"
  dt-bindings: mfd: syscon: Add rk3562 QoS register compatible
  mfd: syscon: Allow syscon nodes without a "syscon" compatible
  mfd: syscon: Remove the platform driver support
  mfd: syscon: Fix race in device_node_get_regmap()
  dt-bindings: mfd: atmel: Convert to YAML schema
  dt-bindings: mfd: atmel,at91sam9260: Convert to YAML schema
  dt-bindings: mfd: sprd,sc2731: Reference sprd,sc2731-efuse bindings
  mfd: tps65219: Remove unused macros & add regmap.h
  mfd: tps65219: Use MFD_CELL macros
  leds: Add LED1202 I2C driver
  dt-bindings: leds: Add LED1202 LED Controller
  Documentation:leds: Add leds-st1202.rst
  mfd: Add support for AAEON UP board FPGA
  mfd: da9052: Store result from fault_log
  mfd: intel_soc_pmic_chtdc_ti: Fix invalid regmap-config max_register value
  mfd: cs42l43: Use devres for remove as well
  ...

Documentation/devicetree/bindings/leds/st,led1202.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/st,led1202.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ST LED1202 LED controllers
+
+maintainers:
+  - Vicentiu Galanopulo <vicentiu.galanopulo@remote-tech.co.uk>
+
+description: |
+  The LED1202 is a 12-channel low quiescent current LED controller
+  programmable via I2C; The output current can be adjusted separately
+  for each channel by 8-bit analog and 12-bit digital dimming control.
+  Datasheet available at
+  https://www.st.com/en/power-management/led1202.html
+
+properties:
+  compatible:
+    const: st,led1202
+
+  reg:
+    maxItems: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+patternProperties:
+  "^led@[0-9a-f]$":
+    type: object
+    $ref: common.yaml#
+    unevaluatedProperties: false
+
+    properties:
+      reg:
+        minimum: 0
+        maximum: 11
+
+    required:
+      - reg
+
+required:
+  - compatible
+  - reg
+  - "#address-cells"
+  - "#size-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/leds/common.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        led-controller@58 {
+            compatible = "st,led1202";
+            reg = <0x58>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            led@0 {
+                reg = <0x0>;
+                function = LED_FUNCTION_STATUS;
+                color = <LED_COLOR_ID_RED>;
+                function-enumerator = <1>;
+            };
+
+            led@1 {
+                reg = <0x1>;
+                function = LED_FUNCTION_STATUS;
+                color = <LED_COLOR_ID_GREEN>;
+                function-enumerator = <2>;
+            };
+
+            led@2 {
+                reg = <0x2>;
+                function = LED_FUNCTION_STATUS;
+                color = <LED_COLOR_ID_BLUE>;
+                function-enumerator = <3>;
+            };
+
+            led@3 {
+                reg = <0x3>;
+                function = LED_FUNCTION_STATUS;
+                color = <LED_COLOR_ID_RED>;
+                function-enumerator = <4>;
+            };
+
+            led@4 {
+                reg = <0x4>;
+                function = LED_FUNCTION_STATUS;
+                color = <LED_COLOR_ID_GREEN>;
+                function-enumerator = <5>;
+            };
+
+            led@5 {
+                reg = <0x5>;
+                function = LED_FUNCTION_STATUS;
+                color = <LED_COLOR_ID_BLUE>;
+                function-enumerator = <6>;
+            };
+
+            led@6 {
+                reg = <0x6>;
+                function = LED_FUNCTION_STATUS;
+                color = <LED_COLOR_ID_RED>;
+                function-enumerator = <7>;
+            };
+
+            led@7 {
+                reg = <0x7>;
+                function = LED_FUNCTION_STATUS;
+                color = <LED_COLOR_ID_GREEN>;
+                function-enumerator = <8>;
+            };
+
+            led@8 {
+                reg = <0x8>;
+                function = LED_FUNCTION_STATUS;
+                color = <LED_COLOR_ID_BLUE>;
+                function-enumerator = <9>;
+            };
+        };
+    };
+...

Documentation/devicetree/bindings/mfd/atmel,at91sam9260-gpbr.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/atmel,at91sam9260-gpbr.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip AT91 General Purpose Backup Registers
+
+maintainers:
+  - Nicolas Ferre <nicolas.ferre@microchip.com>
+
+description:
+  The system controller embeds 256 bits of General Purpose Backup
+  registers organized as 8 32-bit registers.
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - atmel,at91sam9260-gpbr
+          - const: syscon
+      - items:
+          - enum:
+              - microchip,sam9x60-gpbr
+              - microchip,sam9x7-gpbr
+          - const: atmel,at91sam9260-gpbr
+          - const: syscon
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    syscon@fffffd50 {
+        compatible = "atmel,at91sam9260-gpbr", "syscon";
+        reg = <0xfffffd50 0x10>;
+    };

Documentation/devicetree/bindings/mfd/atmel,at91sam9260-matrix.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/atmel,at91sam9260-matrix.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip AT91 Bus Matrix
+
+maintainers:
+  - Nicolas Ferre <nicolas.ferre@microchip.com>
+
+description:
+  The Bus Matrix (MATRIX) implements a multi-layer AHB, based on the
+  AHB-Lite protocol, that enables parallel access paths between multiple
+  masters and slaves in a system, thus increasing the overall bandwidth.
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - atmel,at91sam9260-matrix
+              - atmel,at91sam9261-matrix
+              - atmel,at91sam9263-matrix
+              - atmel,at91sam9rl-matrix
+              - atmel,at91sam9g45-matrix
+              - atmel,at91sam9n12-matrix
+              - atmel,at91sam9x5-matrix
+              - atmel,sama5d3-matrix
+          - const: syscon
+      - items:
+          - enum:
+              - microchip,sam9x60-matrix
+              - microchip,sam9x7-matrix
+          - const: atmel,at91sam9x5-matrix
+          - const: syscon
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    syscon@ffffec00 {
+        compatible = "atmel,sama5d3-matrix", "syscon";
+        reg = <0xffffec00 0x200>;
+    };

Documentation/devicetree/bindings/mfd/atmel-gpbr.txt

-* Device tree bindings for Atmel GPBR (General Purpose Backup Registers)
-
-The GPBR are a set of battery-backed registers.
-
-Required properties:
-- compatible:		Should be one of the following:
-			"atmel,at91sam9260-gpbr", "syscon"
-			"microchip,sam9x60-gpbr", "syscon"
-			"microchip,sam9x7-gpbr", "microchip,sam9x60-gpbr", "syscon"
-- reg:			contains offset/length value of the GPBR memory
-			region.
-
-Example:
-
-gpbr: gpbr@fffffd50 {
-	compatible = "atmel,at91sam9260-gpbr", "syscon";
-	reg = <0xfffffd50 0x10>;
-};

Documentation/devicetree/bindings/mfd/atmel-matrix.txt

-* Device tree bindings for Atmel Bus Matrix
-
-The Bus Matrix registers are used to configure Atmel SoCs internal bus
-behavior (master/slave priorities, undefined burst length type, ...)
-
-Required properties:
-- compatible:		Should be one of the following
-			"atmel,at91sam9260-matrix", "syscon"
-			"atmel,at91sam9261-matrix", "syscon"
-			"atmel,at91sam9263-matrix", "syscon"
-			"atmel,at91sam9rl-matrix", "syscon"
-			"atmel,at91sam9g45-matrix", "syscon"
-			"atmel,at91sam9n12-matrix", "syscon"
-			"atmel,at91sam9x5-matrix", "syscon"
-			"atmel,sama5d3-matrix", "syscon"
-			"microchip,sam9x60-matrix", "syscon"
-			"microchip,sam9x7-matrix", "atmel,at91sam9x5-matrix", "syscon"
-- reg:			Contains offset/length value of the Bus Matrix
-			memory region.
-
-Example:
-
-matrix: matrix@ffffec00 {
-	compatible = "atmel,sama5d3-matrix", "syscon";
-	reg = <0xffffec00 0x200>;
-};

Documentation/devicetree/bindings/mfd/qcom,tcsr.yaml

@@ -42,6 +42,7 @@ properties:
           - qcom,tcsr-apq8064
           - qcom,tcsr-apq8084
           - qcom,tcsr-ipq5332
+          - qcom,tcsr-ipq5424
           - qcom,tcsr-ipq6018
           - qcom,tcsr-ipq8064
           - qcom,tcsr-ipq8074

Documentation/devicetree/bindings/mfd/qnap,ts433-mcu.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/qnap,ts433-mcu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: QNAP NAS on-board Microcontroller
+
+maintainers:
+  - Heiko Stuebner <heiko@sntech.de>
+
+description:
+  QNAP embeds a microcontroller on their NAS devices adding system feature
+  as PWM Fan control, additional LEDs, power button status and more.
+
+properties:
+  compatible:
+    enum:
+      - qnap,ts433-mcu
+
+patternProperties:
+  "^fan-[0-9]+$":
+    $ref: /schemas/hwmon/fan-common.yaml#
+    unevaluatedProperties: false
+
+required:
+  - compatible
+
+additionalProperties: false
+
+examples:
+  - |
+    uart {
+      mcu {
+        compatible = "qnap,ts433-mcu";
+
+        fan-0 {
+          #cooling-cells = <2>;
+          cooling-levels = <0 64 89 128 166 204 221 238>;
+        };
+      };
+    };

Documentation/devicetree/bindings/mfd/rohm,bd71815-pmic.yaml

@@ -50,15 +50,15 @@ properties:
     minimum: 0
     maximum: 1
 
-  rohm,charger-sense-resistor-ohms:
-    minimum: 10000000
-    maximum: 50000000
+  rohm,charger-sense-resistor-micro-ohms:
+    minimum: 10000
+    maximum: 50000
     description: |
-      BD71827 and BD71828 have SAR ADC for measuring charging currents.
-      External sense resistor (RSENSE in data sheet) should be used. If
-      something other but 30MOhm resistor is used the resistance value
-      should be given here in Ohms.
-    default: 30000000
+      BD71815 has SAR ADC for measuring charging currents. External sense
+      resistor (RSENSE in data sheet) should be used. If something other
+      but a 30 mOhm resistor is used the resistance value should be given
+      here in micro Ohms.
+    default: 30000
 
   regulators:
     $ref: /schemas/regulator/rohm,bd71815-regulator.yaml
@@ -67,7 +67,7 @@ properties:
 
   gpio-reserved-ranges:
     description: |
-      Usage of BD71828 GPIO pins can be changed via OTP. This property can be
+      Usage of BD71815 GPIO pins can be changed via OTP. This property can be
       used to mark the pins which should not be configured for GPIO. Please see
       the ../gpio/gpio.txt for more information.
 
@@ -113,7 +113,7 @@ examples:
             gpio-controller;
             #gpio-cells = <2>;
 
-            rohm,charger-sense-resistor-ohms = <10000000>;
+            rohm,charger-sense-resistor-micro-ohms = <10000>;
 
             regulators {
                 buck1: buck1 {

Documentation/devicetree/bindings/mfd/sprd,sc2731.yaml

@@ -67,15 +67,7 @@ patternProperties:
 
   "^efuse@[0-9a-f]+$":
     type: object
-    additionalProperties: true
-    properties:
-      compatible:
-        enum:
-          - sprd,sc2720-efuse
-          - sprd,sc2721-efuse
-          - sprd,sc2723-efuse
-          - sprd,sc2730-efuse
-          - sprd,sc2731-efuse
+    $ref: /schemas/nvmem/sprd,sc2731-efuse.yaml#
 
   "^fuel-gauge@[0-9a-f]+$":
     type: object
@@ -199,7 +191,7 @@ examples:
           };
         };
 
-        adc@480 {
+        pmic_adc: adc@480 {
           compatible = "sprd,sc2731-adc";
           reg = <0x480>;
           interrupt-parent = <&sc2731_pmic>;

Documentation/devicetree/bindings/mfd/syscon.yaml

@@ -27,7 +27,7 @@ select:
     compatible:
       contains:
         enum:
-          - al,alpine-sysfabric-servic
+          - al,alpine-sysfabric-service
           - allwinner,sun8i-a83t-system-controller
           - allwinner,sun8i-h3-system-controller
           - allwinner,sun8i-v3s-system-controller
@@ -103,6 +103,7 @@ select:
           - rockchip,rk3288-qos
           - rockchip,rk3368-qos
           - rockchip,rk3399-qos
+          - rockchip,rk3562-qos
           - rockchip,rk3568-qos
           - rockchip,rk3576-qos
           - rockchip,rk3588-qos
@@ -201,6 +202,7 @@ properties:
           - rockchip,rk3288-qos
           - rockchip,rk3368-qos
           - rockchip,rk3399-qos
+          - rockchip,rk3562-qos
           - rockchip,rk3568-qos
           - rockchip,rk3576-qos
           - rockchip,rk3588-qos
@@ -213,6 +215,7 @@ properties:
           - ti,am625-dss-oldi-io-ctrl
           - ti,am62p-cpsw-mac-efuse
           - ti,am654-dss-oldi-io-ctrl
+          - ti,j784s4-acspcie-proxy-ctrl
           - ti,j784s4-pcie-ctrl
           - ti,keystone-pllctrl
       - const: syscon

Documentation/devicetree/bindings/nvmem/sprd,sc2731-efuse.yaml

@@ -36,33 +36,4 @@ allOf:
   - $ref: nvmem-deprecated-cells.yaml#
 
 unevaluatedProperties: false
-
-examples:
-  - |
-    pmic {
-      #address-cells = <1>;
-      #size-cells = <0>;
-
-      efuse@380 {
-        compatible = "sprd,sc2731-efuse";
-        reg = <0x380>;
-        hwlocks = <&hwlock 12>;
-        #address-cells = <1>;
-        #size-cells = <1>;
-
-        /* Data cells */
-        fgu_calib: calib@6 {
-          reg = <0x6 0x2>;
-          bits = <0 9>;
-        };
-
-        adc_big_scale: calib@24 {
-          reg = <0x24 0x2>;
-        };
-
-        adc_small_scale: calib@26 {
-          reg = <0x26 0x2>;
-        };
-      };
-    };
 ...

Documentation/hwmon/index.rst

@@ -201,6 +201,7 @@ Hardware Monitoring Kernel Drivers
    pxe1610
    pwm-fan
    q54sj108a2
+   qnap-mcu-hwmon
    raspberrypi-hwmon
    sbrmi
    sbtsi_temp

Documentation/hwmon/qnap-mcu-hwmon.rst

+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver qnap-mcu-hwmon
+============================
+
+This driver enables the use of the hardware monitoring and fan control
+of the MCU used on some QNAP network attached storage devices.
+
+Author: Heiko Stuebner <heiko@sntech.de>
+
+Description
+-----------
+
+The driver implements a simple interface for driving the fan controlled by
+setting its PWM output value and exposes the fan rpm and case-temperature
+to user space through hwmon's sysfs interface.
+
+The fan rotation speed returned via the optional 'fan1_input' is calculated
+inside the MCU device.
+
+The driver provides the following sensor accesses in sysfs:
+
+=============== ======= =======================================================
+fan1_input	ro	fan tachometer speed in RPM
+pwm1		rw	relative speed (0-255), 255=max. speed.
+temp1_input	ro	Measured temperature in millicelsius
+=============== ======= =======================================================

Documentation/leds/index.rst

@@ -28,4 +28,5 @@ LEDs
    leds-mlxcpld
    leds-mt6370-rgb
    leds-sc27xx
+   leds-st1202.rst
    leds-qcom-lpg

Documentation/leds/leds-st1202.rst

+.. SPDX-License-Identifier: GPL-2.0
+
+============================================
+Kernel driver for STMicroelectronics LED1202
+============================================
+
+/sys/class/leds/<led>/hw_pattern
+--------------------------------
+
+Specify a hardware pattern for the ST1202 LED. The LED controller
+implements 12 low-side current generators with independent dimming
+control. Internal volatile memory allows the user to store up to 8
+different patterns. Each pattern is a particular output configuration
+in terms of PWM duty-cycle and duration (ms).
+
+To be compatible with the hardware pattern format, maximum 8 tuples of
+brightness (PWM) and duration must be written to hw_pattern.
+
+- Min pattern duration: 22 ms
+- Max pattern duration: 5660 ms
+
+The format of the hardware pattern values should be:
+"brightness duration brightness duration ..."
+
+/sys/class/leds/<led>/repeat
+----------------------------
+
+Specify a pattern repeat number, which is common for all channels.
+Default is 1; negative numbers and 0 are invalid.
+
+This file will always return the originally written repeat number.
+
+When the 255 value is written to it, all patterns will repeat
+indefinitely.

MAINTAINERS

@@ -19158,6 +19158,15 @@ L:	linux-media@vger.kernel.org
 S:	Odd Fixes
 F:	drivers/media/tuners/qm1d1c0042*
+QNAP MCU DRIVER
+M:	Heiko Stuebner <heiko@sntech.de>
+S:	Maintained
+F:	drivers/hwmon/qnap-mcu-hwmon.c
+F:	drivers/input/misc/qnap-mcu-input.c
+F:	drivers/leds/leds-qnap-mcu.c
+F:	drivers/mfd/qnap-mcu.c
+F:	include/linux/mfd/qnap-mcu.h
+
 QNX4 FILESYSTEM
 M:	Anders Larsen <al@alarsen.net>
 S:	Maintained

drivers/hid/hid-sensor-hub.c

@@ -730,23 +730,30 @@ static int sensor_hub_probe(struct hid_device *hdev,
 	return ret;
 }
 
+static int sensor_hub_finalize_pending_fn(struct device *dev, void *data)
+{
+	struct hid_sensor_hub_device *hsdev = dev->platform_data;
+
+	if (hsdev->pending.status)
+		complete(&hsdev->pending.ready);
+
+	return 0;
+}
+
 static void sensor_hub_remove(struct hid_device *hdev)
 {
 	struct sensor_hub_data *data = hid_get_drvdata(hdev);
 	unsigned long flags;
-	int i;
 
 	hid_dbg(hdev, " hardware removed\n");
 	hid_hw_close(hdev);
 	hid_hw_stop(hdev);
+
 	spin_lock_irqsave(&data->lock, flags);
-	for (i = 0; i < data->hid_sensor_client_cnt; ++i) {
-		struct hid_sensor_hub_device *hsdev =
-			data->hid_sensor_hub_client_devs[i].platform_data;
-		if (hsdev->pending.status)
-			complete(&hsdev->pending.ready);
-	}
+	device_for_each_child(&hdev->dev, NULL,
+			      sensor_hub_finalize_pending_fn);
 	spin_unlock_irqrestore(&data->lock, flags);
+
 	mfd_remove_devices(&hdev->dev);
 	mutex_destroy(&data->mutex);
 }

drivers/hwmon/Kconfig

@@ -1822,6 +1822,18 @@ config SENSORS_PWM_FAN
 	  This driver can also be built as a module. If so, the module
 	  will be called pwm-fan.
 
+config SENSORS_QNAP_MCU_HWMON
+	tristate "QNAP MCU hardware monitoring"
+	depends on MFD_QNAP_MCU
+	depends on THERMAL || THERMAL=n
+	help
+	  Say yes here to enable support for fan and temperature sensor
+	  connected to a QNAP MCU, as found in a number of QNAP network
+	  attached storage devices.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called qnap-mcu-hwmon.
+
 config SENSORS_RASPBERRYPI_HWMON
 	tristate "Raspberry Pi voltage monitor"
 	depends on RASPBERRYPI_FIRMWARE || (COMPILE_TEST && !RASPBERRYPI_FIRMWARE)

drivers/hwmon/Makefile

@@ -189,6 +189,7 @@ obj-$(CONFIG_SENSORS_POWERZ)	+= powerz.o
 obj-$(CONFIG_SENSORS_POWR1220)  += powr1220.o
 obj-$(CONFIG_SENSORS_PT5161L)	+= pt5161l.o
 obj-$(CONFIG_SENSORS_PWM_FAN)	+= pwm-fan.o
+obj-$(CONFIG_SENSORS_QNAP_MCU_HWMON)	+= qnap-mcu-hwmon.o
 obj-$(CONFIG_SENSORS_RASPBERRYPI_HWMON)	+= raspberrypi-hwmon.o
 obj-$(CONFIG_SENSORS_SBTSI)	+= sbtsi_temp.o
 obj-$(CONFIG_SENSORS_SBRMI)	+= sbrmi.o

drivers/hwmon/qnap-mcu-hwmon.c

+// SPDX-License-Identifier: GPL-2.0-only
+
+/*
+ * Driver for hwmon elements found on QNAP-MCU devices
+ *
+ * Copyright (C) 2024 Heiko Stuebner <heiko@sntech.de>
+ */
+
+#include <linux/fwnode.h>
+#include <linux/hwmon.h>
+#include <linux/mfd/qnap-mcu.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/thermal.h>
+
+struct qnap_mcu_hwmon {
+	struct qnap_mcu *mcu;
+	struct device *dev;
+
+	unsigned int pwm_min;
+	unsigned int pwm_max;
+
+	struct fwnode_handle *fan_node;
+	unsigned int fan_state;
+	unsigned int fan_max_state;
+	unsigned int *fan_cooling_levels;
+
+	struct thermal_cooling_device *cdev;
+	struct hwmon_chip_info info;
+};
+
+static int qnap_mcu_hwmon_get_rpm(struct qnap_mcu_hwmon *hwm)
+{
+	static const u8 cmd[] = { '@', 'F', 'A' };
+	u8 reply[6];
+	int ret;
+
+	/* poll the fan rpm */
+	ret = qnap_mcu_exec(hwm->mcu, cmd, sizeof(cmd), reply, sizeof(reply));
+	if (ret)
+		return ret;
+
+	/* First 2 bytes must mirror the sent command */
+	if (memcmp(cmd, reply, 2))
+		return -EIO;
+
+	return reply[4] * 30;
+}
+
+static int qnap_mcu_hwmon_get_pwm(struct qnap_mcu_hwmon *hwm)
+{
+	static const u8 cmd[] = { '@', 'F', 'Z', '0' }; /* 0 = fan-id? */
+	u8 reply[4];
+	int ret;
+
+	/* poll the fan pwm */
+	ret = qnap_mcu_exec(hwm->mcu, cmd, sizeof(cmd), reply, sizeof(reply));
+	if (ret)
+		return ret;
+
+	/* First 3 bytes must mirror the sent command */
+	if (memcmp(cmd, reply, 3))
+		return -EIO;
+
+	return reply[3];
+}
+
+static int qnap_mcu_hwmon_set_pwm(struct qnap_mcu_hwmon *hwm, u8 pwm)
+{
+	const u8 cmd[] = { '@', 'F', 'W', '0', pwm }; /* 0 = fan-id?, pwm 0-255 */
+
+	/* set the fan pwm */
+	return qnap_mcu_exec_with_ack(hwm->mcu, cmd, sizeof(cmd));
+}
+
+static int qnap_mcu_hwmon_get_temp(struct qnap_mcu_hwmon *hwm)
+{
+	static const u8 cmd[] = { '@', 'T', '3' };
+	u8 reply[4];
+	int ret;
+
+	/* poll the fan rpm */
+	ret = qnap_mcu_exec(hwm->mcu, cmd, sizeof(cmd), reply, sizeof(reply));
+	if (ret)
+		return ret;
+
+	/* First bytes must mirror the sent command */
+	if (memcmp(cmd, reply, sizeof(cmd)))
+		return -EIO;
+
+	/*
+	 * There is an unknown bit set in bit7.
+	 * Bits [6:0] report the actual temperature as returned by the
+	 * original qnap firmware-tools, so just drop bit7 for now.
+	 */
+	return (reply[3] & 0x7f) * 1000;
+}
+
+static int qnap_mcu_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
+				u32 attr, int channel, long val)
+{
+	struct qnap_mcu_hwmon *hwm = dev_get_drvdata(dev);
+
+	switch (attr) {
+	case hwmon_pwm_input:
+		if (val < 0 || val > 255)
+			return -EINVAL;
+
+		if (val != 0)
+			val = clamp_val(val, hwm->pwm_min, hwm->pwm_max);
+
+		return qnap_mcu_hwmon_set_pwm(hwm, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int qnap_mcu_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+			       u32 attr, int channel, long *val)
+{
+	struct qnap_mcu_hwmon *hwm = dev_get_drvdata(dev);
+	int ret;
+
+	switch (type) {
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_input:
+			ret = qnap_mcu_hwmon_get_pwm(hwm);
+			if (ret < 0)
+				return ret;
+
+			*val = ret;
+			return 0;
+		default:
+			return -EOPNOTSUPP;
+		}
+	case hwmon_fan:
+		ret = qnap_mcu_hwmon_get_rpm(hwm);
+		if (ret < 0)
+			return ret;
+
+		*val = ret;
+		return 0;
+	case hwmon_temp:
+		ret = qnap_mcu_hwmon_get_temp(hwm);
+		if (ret < 0)
+			return ret;
+
+		*val = ret;
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t qnap_mcu_hwmon_is_visible(const void *data,
+					 enum hwmon_sensor_types type,
+					 u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_temp:
+		return 0444;
+
+	case hwmon_pwm:
+		return 0644;
+
+	case hwmon_fan:
+		return 0444;
+
+	default:
+		return 0;
+	}
+}
+
+static const struct hwmon_ops qnap_mcu_hwmon_hwmon_ops = {
+	.is_visible = qnap_mcu_hwmon_is_visible,
+	.read = qnap_mcu_hwmon_read,
+	.write = qnap_mcu_hwmon_write,
+};
+
+/* thermal cooling device callbacks */
+static int qnap_mcu_hwmon_get_max_state(struct thermal_cooling_device *cdev,
+					unsigned long *state)
+{
+	struct qnap_mcu_hwmon *hwm = cdev->devdata;
+
+	if (!hwm)
+		return -EINVAL;
+
+	*state = hwm->fan_max_state;
+
+	return 0;
+}
+
+static int qnap_mcu_hwmon_get_cur_state(struct thermal_cooling_device *cdev,
+					unsigned long *state)
+{
+	struct qnap_mcu_hwmon *hwm = cdev->devdata;
+
+	if (!hwm)
+		return -EINVAL;
+
+	*state = hwm->fan_state;
+
+	return 0;
+}
+
+static int qnap_mcu_hwmon_set_cur_state(struct thermal_cooling_device *cdev,
+					unsigned long state)
+{
+	struct qnap_mcu_hwmon *hwm = cdev->devdata;
+	int ret;
+
+	if (!hwm || state > hwm->fan_max_state)
+		return -EINVAL;
+
+	if (state == hwm->fan_state)
+		return 0;
+
+	ret = qnap_mcu_hwmon_set_pwm(hwm, hwm->fan_cooling_levels[state]);
+	if (ret)
+		return ret;
+
+	hwm->fan_state = state;
+
+	return ret;
+}
+
+static const struct thermal_cooling_device_ops qnap_mcu_hwmon_cooling_ops = {
+	.get_max_state = qnap_mcu_hwmon_get_max_state,
+	.get_cur_state = qnap_mcu_hwmon_get_cur_state,
+	.set_cur_state = qnap_mcu_hwmon_set_cur_state,
+};
+
+static void devm_fan_node_release(void *data)
+{
+	struct qnap_mcu_hwmon *hwm = data;
+
+	fwnode_handle_put(hwm->fan_node);
+}
+
+static int qnap_mcu_hwmon_get_cooling_data(struct device *dev, struct qnap_mcu_hwmon *hwm)
+{
+	struct fwnode_handle *fwnode;
+	int num, i, ret;
+
+	fwnode = device_get_named_child_node(dev->parent, "fan-0");
+	if (!fwnode)
+		return 0;
+
+	/* if we found the fan-node, we're keeping it until device-unbind */
+	hwm->fan_node = fwnode;
+	ret = devm_add_action_or_reset(dev, devm_fan_node_release, hwm);
+	if (ret)
+		return ret;
+
+	num = fwnode_property_count_u32(fwnode, "cooling-levels");
+	if (num <= 0)
+		return dev_err_probe(dev, num ? : -EINVAL,
+				     "Failed to count elements in 'cooling-levels'\n");
+
+	hwm->fan_cooling_levels = devm_kcalloc(dev, num, sizeof(u32),
+					       GFP_KERNEL);
+	if (!hwm->fan_cooling_levels)
+		return -ENOMEM;
+
+	ret = fwnode_property_read_u32_array(fwnode, "cooling-levels",
+					     hwm->fan_cooling_levels, num);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to read 'cooling-levels'\n");
+
+	for (i = 0; i < num; i++) {
+		if (hwm->fan_cooling_levels[i] > hwm->pwm_max)
+			return dev_err_probe(dev, -EINVAL, "fan state[%d]:%d > %d\n", i,
+					     hwm->fan_cooling_levels[i], hwm->pwm_max);
+	}
+
+	hwm->fan_max_state = num - 1;
+
+	return 0;
+}
+
+static const struct hwmon_channel_info * const qnap_mcu_hwmon_channels[] = {
+	HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT),
+	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT),
+	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+	NULL
+};
+
+static int qnap_mcu_hwmon_probe(struct platform_device *pdev)
+{
+	struct qnap_mcu *mcu = dev_get_drvdata(pdev->dev.parent);
+	const struct qnap_mcu_variant *variant = pdev->dev.platform_data;
+	struct qnap_mcu_hwmon *hwm;
+	struct thermal_cooling_device *cdev;
+	struct device *dev = &pdev->dev;
+	struct device *hwmon;
+	int ret;
+
+	hwm = devm_kzalloc(dev, sizeof(*hwm), GFP_KERNEL);
+	if (!hwm)
+		return -ENOMEM;
+
+	hwm->mcu = mcu;
+	hwm->dev = &pdev->dev;
+	hwm->pwm_min = variant->fan_pwm_min;
+	hwm->pwm_max = variant->fan_pwm_max;
+
+	platform_set_drvdata(pdev, hwm);
+
+	/*
+	 * Set duty cycle to maximum allowed.
+	 */
+	ret = qnap_mcu_hwmon_set_pwm(hwm, hwm->pwm_max);
+	if (ret)
+		return ret;
+
+	hwm->info.ops = &qnap_mcu_hwmon_hwmon_ops;
+	hwm->info.info = qnap_mcu_hwmon_channels;
+
+	ret = qnap_mcu_hwmon_get_cooling_data(dev, hwm);
+	if (ret)
+		return ret;
+
+	hwm->fan_state = hwm->fan_max_state;
+
+	hwmon = devm_hwmon_device_register_with_info(dev, "qnapmcu",
+						     hwm, &hwm->info, NULL);
+	if (IS_ERR(hwmon))
+		return dev_err_probe(dev, PTR_ERR(hwmon), "Failed to register hwmon device\n");
+
+	/*
+	 * Only register cooling device when we found cooling-levels.
+	 * qnap_mcu_hwmon_get_cooling_data() will fail when reading malformed
+	 * levels and only succeed with either no or correct cooling levels.
+	 */
+	if (IS_ENABLED(CONFIG_THERMAL) && hwm->fan_cooling_levels) {
+		cdev = devm_thermal_of_cooling_device_register(dev,
+					to_of_node(hwm->fan_node), "qnap-mcu-hwmon",
+					hwm, &qnap_mcu_hwmon_cooling_ops);
+		if (IS_ERR(cdev))
+			return dev_err_probe(dev, PTR_ERR(cdev),
+				"Failed to register qnap-mcu-hwmon as cooling device\n");
+		hwm->cdev = cdev;
+	}
+
+	return 0;
+}
+
+static struct platform_driver qnap_mcu_hwmon_driver = {
+	.probe = qnap_mcu_hwmon_probe,
+	.driver = {
+		.name = "qnap-mcu-hwmon",
+	},
+};
+module_platform_driver(qnap_mcu_hwmon_driver);
+
+MODULE_ALIAS("platform:qnap-mcu-hwmon");
+MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
+MODULE_DESCRIPTION("QNAP MCU hwmon driver");
+MODULE_LICENSE("GPL");