iio: adc: add Nuvoton NCT720x ADC driver

This adds a binding specification for the Nuvoton NCT7201/NCT7202 family of ADCs.

Signed-off-by Eason Yang <[email protected]>

---
  .../bindings/iio/adc/nuvoton,nct720x.yaml     | 47 +++++++++++++++++++
  MAINTAINERS                                   |  1 +
  2 files changed, 48 insertions(+)

create mode 100644 Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +14 -0

new file mode 100644
index 000000000000..3052039af10e
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/nuvoton,nct720x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Nuvoton nct7202 and similar ADCs
+
+maintainers:
+  - Eason Yang <[email protected]>
+
+description: |
+   Family of ADCs with i2c interface.
+

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +8 -0

+    description: number of data bits per read vin
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [8, 16]
+
+required:
+  - compatible
+  - reg
+  - read-vin-data-size

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +5 -0

+            compatible = "nuvoton,nct7202";
+            reg = <0x1d>;
+            read-vin-data-size = <8>;
+        };
+    };

MAINTAINERS +1 -0

index 91d0609db61b..68570c58e7aa 100644
@@ -2746,6 +2746,7 @@ L:	[email protected] (moderated for non-subscribers)
  S:	Supported
  F:	Documentation/devicetree/bindings/*/*/*npcm*
  F:	Documentation/devicetree/bindings/*/*npcm*
+F:	Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml
  F:	Documentation/devicetree/bindings/rtc/nuvoton,nct3018y.yaml
  F:	arch/arm/boot/dts/nuvoton/nuvoton-npcm*
  F:	arch/arm/mach-npcm/

Quoted 30 lines

This adds a binding specification for the Nuvoton NCT7201/NCT7202 family of ADCs.

Signed-off-by Eason Yang <[email protected]>

---
  .../bindings/iio/adc/nuvoton,nct720x.yaml     | 47 +++++++++++++++++++
  MAINTAINERS                                   |  1 +
  2 files changed, 48 insertions(+)

create mode 100644 Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +14 -0

new file mode 100644
index 000000000000..3052039af10e
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/nuvoton,nct720x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Nuvoton nct7202 and similar ADCs
+
+maintainers:
+  - Eason Yang <[email protected]>
+
+description: |
+   Family of ADCs with i2c interface.
+

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 24

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +10 -0

+properties:
+  compatible:
+    enum:
+      - nuvoton,nct7201
+      - nuvoton,nct7202
+
+  reg:
+    maxItems: 1
+
+  read-vin-data-size:

Is it generic property or vendor property? I tried to find in the
https://github.com/torvalds/linux/tree/master/Documentation/devicetree/bindings
, but it seems this property hasn't been used on other devices.

If it is vendor property, then I think it should include a vendor prefix. For examples:

https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/adi%2Cad7780.yaml#L50
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/fsl%2Cvf610-adc.yaml#L42
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/st%2Cstmpe-adc.yaml#L22

Quoted 8 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +8 -0

+    description: number of data bits per read vin
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [8, 16]
+
+required:
+  - compatible
+  - reg
+  - read-vin-data-size

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 42

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +10 -0

+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        nct7202@1d {

I think the Node name should follow
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation

For some examples that were merged before

https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/adi%2Cad7091r5.yaml#L102
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/maxim%2Cmax1238.yaml#L73
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/ti%2Cadc081c.yaml#L49

Quoted 17 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +5 -0

+            compatible = "nuvoton,nct7202";
+            reg = <0x1d>;
+            read-vin-data-size = <8>;
+        };
+    };

MAINTAINERS +1 -0

index 91d0609db61b..68570c58e7aa 100644
@@ -2746,6 +2746,7 @@ L:      [email protected] (moderated for non-subscribers)
  S:  Supported
  F:  Documentation/devicetree/bindings/*/*/*npcm*
  F:  Documentation/devicetree/bindings/*/*npcm*
+F:   Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml
  F:  Documentation/devicetree/bindings/rtc/nuvoton,nct3018y.yaml
  F:  arch/arm/boot/dts/nuvoton/nuvoton-npcm*
  F:  arch/arm/mach-npcm/

Dear Chanh Nguyen,

Thank you for your response.

Chanh Nguyen <[email protected]> 於 2024年11月6日 週三 下午12:58寫道：

Quoted 52 lines · Eason Yang

Quoted 30 lines

This adds a binding specification for the Nuvoton NCT7201/NCT7202 family of ADCs.

Signed-off-by Eason Yang <[email protected]>

---
  .../bindings/iio/adc/nuvoton,nct720x.yaml     | 47 +++++++++++++++++++
  MAINTAINERS                                   |  1 +
  2 files changed, 48 insertions(+)

create mode 100644 Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +14 -0

new file mode 100644
index 000000000000..3052039af10e
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/nuvoton,nct720x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Nuvoton nct7202 and similar ADCs
+
+maintainers:
+  - Eason Yang <[email protected]>
+
+description: |
+   Family of ADCs with i2c interface.
+

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 24

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +10 -0

+properties:
+  compatible:
+    enum:
+      - nuvoton,nct7201
+      - nuvoton,nct7202
+
+  reg:
+    maxItems: 1
+
+  read-vin-data-size:  

Is it generic property or vendor property? I tried to find in the
https://github.com/torvalds/linux/tree/master/Documentation/devicetree/bindings
, but it seems this property hasn't been used on other devices.

If it is vendor property, then I think it should include a vendor prefix. For examples:

Quoted 5 lines

https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/adi%2Cad7780.yaml#L50
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/fsl%2Cvf610-adc.yaml#L42
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/st%2Cstmpe-adc.yaml#L22

I would add a vendor prefix for it.

Quoted 24 lines

Quoted 9 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +8 -0

+    description: number of data bits per read vin
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [8, 16]
+
+required:
+  - compatible
+  - reg
+  - read-vin-data-size

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 42

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +10 -0

+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        nct7202@1d {  

I think the Node name should follow
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation

Quoted 6 lines

For some examples that were merged before

https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/adi%2Cad7091r5.yaml#L102
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/maxim%2Cmax1238.yaml#L73
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/ti%2Cadc081c.yaml#L49

I would change it for the node naming.

Quoted 18 lines

Quoted 17 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +5 -0

+            compatible = "nuvoton,nct7202";
+            reg = <0x1d>;
+            read-vin-data-size = <8>;
+        };
+    };

MAINTAINERS +1 -0

index 91d0609db61b..68570c58e7aa 100644
@@ -2746,6 +2746,7 @@ L:      [email protected] (moderated for non-subscribers)
  S:  Supported
  F:  Documentation/devicetree/bindings/*/*/*npcm*
  F:  Documentation/devicetree/bindings/*/*npcm*
+F:   Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml
  F:  Documentation/devicetree/bindings/rtc/nuvoton,nct3018y.yaml
  F:  arch/arm/boot/dts/nuvoton/nuvoton-npcm*
  F:  arch/arm/mach-npcm/  

Quoted 57 lines · On Wed, 6 Nov 2024 17:22:35 +0800 Yu-Hsian Yang <[email protected]> wrote:

Dear Chanh Nguyen,

Thank you for your response.

Chanh Nguyen <[email protected]> 於 2024年11月6日 週三 下午12:58寫道：

Quoted 52 lines · Eason Yang

Quoted 30 lines

This adds a binding specification for the Nuvoton NCT7201/NCT7202 family of ADCs.

Signed-off-by Eason Yang <[email protected]>

---
  .../bindings/iio/adc/nuvoton,nct720x.yaml     | 47 +++++++++++++++++++
  MAINTAINERS                                   |  1 +
  2 files changed, 48 insertions(+)

create mode 100644 Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +14 -0

new file mode 100644
index 000000000000..3052039af10e
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/nuvoton,nct720x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Nuvoton nct7202 and similar ADCs
+
+maintainers:
+  - Eason Yang <[email protected]>
+
+description: |
+   Family of ADCs with i2c interface.
+

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 24

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +10 -0

+properties:
+  compatible:
+    enum:
+      - nuvoton,nct7201
+      - nuvoton,nct7202
+
+  reg:
+    maxItems: 1
+
+  read-vin-data-size:    

Is it generic property or vendor property? I tried to find in the
https://github.com/torvalds/linux/tree/master/Documentation/devicetree/bindings
, but it seems this property hasn't been used on other devices.

If it is vendor property, then I think it should include a vendor prefix. For examples:

Quoted 7 lines

Quoted 5 lines

https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/adi%2Cad7780.yaml#L50
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/fsl%2Cvf610-adc.yaml#L42
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/st%2Cstmpe-adc.yaml#L22

I would add a vendor prefix for it.

Why do we want this at all? Is this device sufficiently high performance that Linux will ever want to trade of resolution against sampling speed?

If so that seems like a policy control that belongs in userspace. Note that to support that in IIO I would want a strong justification for why we dno't just set it to 16 always. We just go for maximum resolution in the vast majority of drivers that support control of this.

Quoted 53 lines

Quoted 26 lines

Quoted 11 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +8 -0

+    description: number of data bits per read vin
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [8, 16]
+
+required:
+  - compatible
+  - reg
+  - read-vin-data-size

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 42

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +10 -0

+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        nct7202@1d {    

I think the Node name should follow
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation

Quoted 6 lines

For some examples that were merged before

https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/adi%2Cad7091r5.yaml#L102
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/maxim%2Cmax1238.yaml#L73
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/ti%2Cadc081c.yaml#L49

I would change it for the node naming.

Quoted 18 lines

Quoted 17 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +5 -0

+            compatible = "nuvoton,nct7202";
+            reg = <0x1d>;
+            read-vin-data-size = <8>;
+        };
+    };

MAINTAINERS +1 -0

index 91d0609db61b..68570c58e7aa 100644
@@ -2746,6 +2746,7 @@ L:      [email protected] (moderated for non-subscribers)
  S:  Supported
  F:  Documentation/devicetree/bindings/*/*/*npcm*
  F:  Documentation/devicetree/bindings/*/*npcm*
+F:   Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml
  F:  Documentation/devicetree/bindings/rtc/nuvoton,nct3018y.yaml
  F:  arch/arm/boot/dts/nuvoton/nuvoton-npcm*
  F:  arch/arm/mach-npcm/    

Quoted 68 lines · On Sat, 9 Nov 2024 13:42:28 +0000 Jonathan Cameron <[email protected]> wrote:

Quoted 57 lines · On Wed, 6 Nov 2024 17:22:35 +0800 Yu-Hsian Yang <[email protected]> wrote:

Dear Chanh Nguyen,

Thank you for your response.

Chanh Nguyen <[email protected]> 於 2024年11月6日 週三 下午12:58寫道：

Quoted 52 lines · Eason Yang

Quoted 30 lines

This adds a binding specification for the Nuvoton NCT7201/NCT7202 family of ADCs.

Signed-off-by Eason Yang <[email protected]>

---
  .../bindings/iio/adc/nuvoton,nct720x.yaml     | 47 +++++++++++++++++++
  MAINTAINERS                                   |  1 +
  2 files changed, 48 insertions(+)

create mode 100644 Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +14 -0

new file mode 100644
index 000000000000..3052039af10e
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/nuvoton,nct720x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Nuvoton nct7202 and similar ADCs
+
+maintainers:
+  - Eason Yang <[email protected]>
+
+description: |
+   Family of ADCs with i2c interface.
+

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 24

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +10 -0

+properties:
+  compatible:
+    enum:
+      - nuvoton,nct7201
+      - nuvoton,nct7202
+
+  reg:
+    maxItems: 1
+
+  read-vin-data-size:

Is it generic property or vendor property? I tried to find in the
https://github.com/torvalds/linux/tree/master/Documentation/devicetree/bindings
, but it seems this property hasn't been used on other devices.

If it is vendor property, then I think it should include a vendor prefix. For examples:

Quoted 7 lines

Quoted 5 lines

https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/adi%2Cad7780.yaml#L50
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/fsl%2Cvf610-adc.yaml#L42
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/st%2Cstmpe-adc.yaml#L22

I would add a vendor prefix for it.

Quoted 8 lines

Why do we want this at all? Is this device sufficiently high performance that Linux will ever want to trade of resolution against sampling speed?

If so that seems like a policy control that belongs in userspace. Note that to support that in IIO I would want a strong justification for why we dno't just set it to 16 always. We just go for maximum resolution in the vast majority of drivers that support control of this.

I'd misunderstood what this is. It's a control no what the i2c word size is. Do we actually care about supporting rubbish i2c controllers? How many can't do a word access?

If you do it should be detected from the controller rather than in DT.

Quoted 55 lines

Quoted 53 lines

Quoted 26 lines

Quoted 11 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +8 -0

+    description: number of data bits per read vin
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [8, 16]
+
+required:
+  - compatible
+  - reg
+  - read-vin-data-size

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 42

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +10 -0

+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        nct7202@1d {

I think the Node name should follow
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation

Quoted 6 lines

For some examples that were merged before

https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/adi%2Cad7091r5.yaml#L102
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/maxim%2Cmax1238.yaml#L73
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/ti%2Cadc081c.yaml#L49

I would change it for the node naming.

Quoted 18 lines

Quoted 17 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +5 -0

+            compatible = "nuvoton,nct7202";
+            reg = <0x1d>;
+            read-vin-data-size = <8>;
+        };
+    };

MAINTAINERS +1 -0

index 91d0609db61b..68570c58e7aa 100644
@@ -2746,6 +2746,7 @@ L:      [email protected] (moderated for non-subscribers)
  S:  Supported
  F:  Documentation/devicetree/bindings/*/*/*npcm*
  F:  Documentation/devicetree/bindings/*/*npcm*
+F:   Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml
  F:  Documentation/devicetree/bindings/rtc/nuvoton,nct3018y.yaml
  F:  arch/arm/boot/dts/nuvoton/nuvoton-npcm*
  F:  arch/arm/mach-npcm/

Dear Jonathan Cameron,

For property read-vin-data-size, we have a internal discussion.

For Nuvoton NCT7201/NCT7202 chip,
Take an example as to Vin1:
The VIN reading supports Byte read (One Byte) and Word read (Two Byte)

For Byte read:
First read Index 00h to get VIN1 MSB, then read Index 0Fh Bit 3~7 to get VIN1 LSB.
Index 0Fh is a shared LSB for all VINs.

For Word read:
Read Index 00h and get 2 Byte (VIN1 MSB and VIN1 LSB).

We would refer your suggestion,
we declare a property named "nvuoton,read-vin-data-size" with default value 16 for user to use.

Jonathan Cameron <[email protected]> 於 2024年11月9日 週六 下午10:29寫道：

Quoted 142 lines

Quoted 68 lines · On Sat, 9 Nov 2024 13:42:28 +0000 Jonathan Cameron <[email protected]> wrote:

Quoted 57 lines · On Wed, 6 Nov 2024 17:22:35 +0800 Yu-Hsian Yang <[email protected]> wrote:

Dear Chanh Nguyen,

Thank you for your response.

Chanh Nguyen <[email protected]> 於 2024年11月6日 週三 下午12:58寫道：

Quoted 52 lines · Eason Yang

Quoted 30 lines

This adds a binding specification for the Nuvoton NCT7201/NCT7202 family of ADCs.

Signed-off-by Eason Yang <[email protected]>

---
  .../bindings/iio/adc/nuvoton,nct720x.yaml     | 47 +++++++++++++++++++
  MAINTAINERS                                   |  1 +
  2 files changed, 48 insertions(+)

create mode 100644 Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +14 -0

new file mode 100644
index 000000000000..3052039af10e
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/nuvoton,nct720x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Nuvoton nct7202 and similar ADCs
+
+maintainers:
+  - Eason Yang <[email protected]>
+
+description: |
+   Family of ADCs with i2c interface.
+

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 24

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +10 -0

+properties:
+  compatible:
+    enum:
+      - nuvoton,nct7201
+      - nuvoton,nct7202
+
+  reg:
+    maxItems: 1
+
+  read-vin-data-size:  

Is it generic property or vendor property? I tried to find in the
https://github.com/torvalds/linux/tree/master/Documentation/devicetree/bindings
, but it seems this property hasn't been used on other devices.

If it is vendor property, then I think it should include a vendor prefix. For examples:

Quoted 7 lines

Quoted 5 lines

https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/adi%2Cad7780.yaml#L50
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/fsl%2Cvf610-adc.yaml#L42
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/st%2Cstmpe-adc.yaml#L22

I would add a vendor prefix for it.

Quoted 8 lines

Why do we want this at all? Is this device sufficiently high performance that Linux will ever want to trade of resolution against sampling speed?

If so that seems like a policy control that belongs in userspace. Note that to support that in IIO I would want a strong justification for why we dno't just set it to 16 always. We just go for maximum resolution in the vast majority of drivers that support control of this.

I'd misunderstood what this is. It's a control no what the i2c word size is. Do we actually care about supporting rubbish i2c controllers? How many can't do a word access?

If you do it should be detected from the controller rather than in DT.

Quoted 55 lines

Quoted 53 lines

Quoted 26 lines

Quoted 11 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +8 -0

+    description: number of data bits per read vin
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [8, 16]
+
+required:
+  - compatible
+  - reg
+  - read-vin-data-size

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 42

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +10 -0

+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        nct7202@1d {  

I think the Node name should follow
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation

Quoted 6 lines

For some examples that were merged before

https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/adi%2Cad7091r5.yaml#L102
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/maxim%2Cmax1238.yaml#L73
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/ti%2Cadc081c.yaml#L49

I would change it for the node naming.

Quoted 18 lines

Quoted 17 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +5 -0

+            compatible = "nuvoton,nct7202";
+            reg = <0x1d>;
+            read-vin-data-size = <8>;
+        };
+    };

MAINTAINERS +1 -0

index 91d0609db61b..68570c58e7aa 100644
@@ -2746,6 +2746,7 @@ L:      [email protected] (moderated for non-subscribers)
  S:  Supported
  F:  Documentation/devicetree/bindings/*/*/*npcm*
  F:  Documentation/devicetree/bindings/*/*npcm*
+F:   Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml
  F:  Documentation/devicetree/bindings/rtc/nuvoton,nct3018y.yaml
  F:  arch/arm/boot/dts/nuvoton/nuvoton-npcm*
  F:  arch/arm/mach-npcm/  

Quoted 13 lines · On Mon, 11 Nov 2024 15:45:03 +0800 Yu-Hsian Yang <[email protected]> wrote:

Dear Jonathan Cameron,

For property read-vin-data-size, we have a internal discussion.

For Nuvoton NCT7201/NCT7202 chip,
Take an example as to Vin1:
The VIN reading supports Byte read (One Byte) and Word read (Two Byte)

For Byte read:
First read Index 00h to get VIN1 MSB, then read Index 0Fh Bit 3~7 to get VIN1 LSB.
Index 0Fh is a shared LSB for all VINs.

Quoted 6 lines

For Word read:
Read Index 00h and get 2 Byte (VIN1 MSB and VIN1 LSB).

We would refer your suggestion,
we declare a property named "nvuoton,read-vin-data-size" with default value 16 for user to use.

Thanks for the info. If the i2c controller allows word read then the right thing is to always use it.

Just check for I2C_FUNC_SMBUS_READ_WORD_DATA with
i2c_check_functionality()

If it's supported use i2c_smbus_read_word_swapped() if not, do the i2c_smbus_read_byte() approach.

We don't need to want this in DT as it is a property of the smbus controller, not this device.

Jonathan

Quoted 144 lines

Jonathan Cameron <[email protected]> 於 2024年11月9日 週六 下午10:29寫道：

Quoted 142 lines

Quoted 68 lines · On Sat, 9 Nov 2024 13:42:28 +0000 Jonathan Cameron <[email protected]> wrote:

Quoted 57 lines · On Wed, 6 Nov 2024 17:22:35 +0800 Yu-Hsian Yang <[email protected]> wrote:

Dear Chanh Nguyen,

Thank you for your response.

Chanh Nguyen <[email protected]> 於 2024年11月6日 週三 下午12:58寫道：

Quoted 52 lines · Eason Yang

Quoted 30 lines

This adds a binding specification for the Nuvoton NCT7201/NCT7202 family of ADCs.

Signed-off-by Eason Yang <[email protected]>

---
  .../bindings/iio/adc/nuvoton,nct720x.yaml     | 47 +++++++++++++++++++
  MAINTAINERS                                   |  1 +
  2 files changed, 48 insertions(+)

create mode 100644 Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +14 -0

new file mode 100644
index 000000000000..3052039af10e
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/nuvoton,nct720x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Nuvoton nct7202 and similar ADCs
+
+maintainers:
+  - Eason Yang <[email protected]>
+
+description: |
+   Family of ADCs with i2c interface.
+

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 24

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +10 -0

+properties:
+  compatible:
+    enum:
+      - nuvoton,nct7201
+      - nuvoton,nct7202
+
+  reg:
+    maxItems: 1
+
+  read-vin-data-size:

Is it generic property or vendor property? I tried to find in the
https://github.com/torvalds/linux/tree/master/Documentation/devicetree/bindings
, but it seems this property hasn't been used on other devices.

If it is vendor property, then I think it should include a vendor prefix. For examples:

Quoted 7 lines

Quoted 5 lines

https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/adi%2Cad7780.yaml#L50
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/fsl%2Cvf610-adc.yaml#L42
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/st%2Cstmpe-adc.yaml#L22

I would add a vendor prefix for it.

Quoted 8 lines

Why do we want this at all? Is this device sufficiently high performance that Linux will ever want to trade of resolution against sampling speed?

If so that seems like a policy control that belongs in userspace. Note that to support that in IIO I would want a strong justification for why we dno't just set it to 16 always. We just go for maximum resolution in the vast majority of drivers that support control of this.

I'd misunderstood what this is. It's a control no what the i2c word size is. Do we actually care about supporting rubbish i2c controllers? How many can't do a word access?

If you do it should be detected from the controller rather than in DT.

Quoted 55 lines

Quoted 53 lines

Quoted 26 lines

Quoted 11 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +8 -0

+    description: number of data bits per read vin
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [8, 16]
+
+required:
+  - compatible
+  - reg
+  - read-vin-data-size

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 42

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +10 -0

+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        nct7202@1d {

I think the Node name should follow
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation

Quoted 6 lines

For some examples that were merged before

https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/adi%2Cad7091r5.yaml#L102
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/maxim%2Cmax1238.yaml#L73
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/ti%2Cadc081c.yaml#L49

I would change it for the node naming.

Quoted 18 lines

Quoted 17 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +5 -0

+            compatible = "nuvoton,nct7202";
+            reg = <0x1d>;
+            read-vin-data-size = <8>;
+        };
+    };

MAINTAINERS +1 -0

index 91d0609db61b..68570c58e7aa 100644
@@ -2746,6 +2746,7 @@ L:      [email protected] (moderated for non-subscribers)
  S:  Supported
  F:  Documentation/devicetree/bindings/*/*/*npcm*
  F:  Documentation/devicetree/bindings/*/*npcm*
+F:   Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml
  F:  Documentation/devicetree/bindings/rtc/nuvoton,nct3018y.yaml
  F:  arch/arm/boot/dts/nuvoton/nuvoton-npcm*
  F:  arch/arm/mach-npcm/

Dear Jonathan Cameron,

Thank you for your advice.

I would remove the "nvuoton,read-vin-data-size" property.

Read VIN info can use word read or byte read, and other registers should use byte read.
If I use word read for VIN info and byte read for other registers, I encounter an issue when I use regmap instead of i2c smbus API.

I need two regmap configs with val_bits 8/16.
After I call devm_regmap_init_i2c these two configs,
the error message:
"debugfs: Directory '5-001d' with parent 'regmap' already present!"

Do you have any suggestions?

Quoted 11 lines

Dear Jonathan Cameron,

Thank you for your advice.

I would remove the "nvuoton,read-vin-data-size" property.

Read VIN info can use word read or byte read, and other registers should use byte read.
If I use word read for VIN info and byte read for other registers, I encounter an issue when I use regmap instead of i2c smbus API.

Quoted 7 lines

I need two regmap configs with val_bits 8/16.
After I call devm_regmap_init_i2c these two configs,
the error message:
"debugfs: Directory '5-001d' with parent 'regmap' already present!"

Do you have any suggestions?

Give each regmap a unique name, like "5-001d-8bit" and "5-001d-16bit".

Quoted 30 lines · Eason Yang

This adds a binding specification for the Nuvoton NCT7201/NCT7202 family of ADCs.

Signed-off-by Eason Yang <[email protected]>

---
  .../bindings/iio/adc/nuvoton,nct720x.yaml     | 47 +++++++++++++++++++
  MAINTAINERS                                   |  1 +
  2 files changed, 48 insertions(+)

create mode 100644 Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +14 -0

new file mode 100644
index 000000000000..3052039af10e
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/nuvoton,nct720x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Nuvoton nct7202 and similar ADCs
+
+maintainers:
+  - Eason Yang <[email protected]>
+
+description: |
+   Family of ADCs with i2c interface.
+

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 24

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +10 -0

+properties:
+  compatible:
+    enum:
+      - nuvoton,nct7201
+      - nuvoton,nct7202
+
+  reg:
+    maxItems: 1
+
+  read-vin-data-size:

Is it generic property or vendor property? I tried to find in the
https://github.com/torvalds/linux/tree/master/Documentation/devicetree/bindings
, but it seems this property hasn't been used on other devices.

If it is vendor property, then I think it should include a vendor prefix. For examples:

https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/adi%2Cad7780.yaml#L50
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/fsl%2Cvf610-adc.yaml#L42
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/st%2Cstmpe-adc.yaml#L22

Quoted 48 lines · Eason Yang

Quoted 30 lines

This adds a binding specification for the Nuvoton NCT7201/NCT7202 family of ADCs.

Signed-off-by Eason Yang <[email protected]>

---
  .../bindings/iio/adc/nuvoton,nct720x.yaml     | 47 +++++++++++++++++++
  MAINTAINERS                                   |  1 +
  2 files changed, 48 insertions(+)

create mode 100644 Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +14 -0

new file mode 100644
index 000000000000..3052039af10e
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/nuvoton,nct720x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Nuvoton nct7202 and similar ADCs
+
+maintainers:
+  - Eason Yang <[email protected]>
+
+description: |
+   Family of ADCs with i2c interface.
+

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 24

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +10 -0

+properties:
+  compatible:
+    enum:
+      - nuvoton,nct7201
+      - nuvoton,nct7202
+
+  reg:
+    maxItems: 1
+
+  read-vin-data-size:

Is it generic property or vendor property? I tried to find in the
https://github.com/torvalds/linux/tree/master/Documentation/devicetree/bindings
, but it seems this property hasn't been used on other devices.

Quoted 6 lines

If it is vendor property, then I think it should include a vendor prefix. For examples:

https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/adi%2Cad7780.yaml#L50
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/fsl%2Cvf610-adc.yaml#L42
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/iio/adc/st%2Cstmpe-adc.yaml#L22

An explanation of why it cannot be determined from the compatible would also be good. Two compatibles and two values makes me a little suspicious!

Quoted 9 lines

This adds a binding specification for the Nuvoton NCT7201/NCT7202 family of ADCs.

Signed-off-by Eason Yang <[email protected]>

---
  .../bindings/iio/adc/nuvoton,nct720x.yaml     | 47 +++++++++++++++++++
  MAINTAINERS                                   |  1 +
  2 files changed, 48 insertions(+)

create mode 100644

Quoted 2 lines

diff --git

Quoted 23 lines

new file mode 100644
index 000000000000..3052039af10e

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +18 -0

@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/nuvoton,nct720x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Nuvoton nct7202 and similar ADCs
+
+maintainers:
+  - Eason Yang <[email protected]>
+
+description: |
+   Family of ADCs with i2c interface.
+
+properties:
+  compatible:
+    enum:
+      - nuvoton,nct7201

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 24

Quoted 6 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +6 -0

+      - nuvoton,nct7202
+
+  reg:
+    maxItems: 1
+
+  read-vin-data-size:

Is it generic property or vendor property? I tried to find in the

, but it seems this property hasn't been used on other devices.

If it is vendor property, then I think it should include a vendor prefix. For examples:

Quoted 14 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +12 -0

+    description: number of data bits per read vin
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [8, 16]
+
+required:
+  - compatible
+  - reg
+  - read-vin-data-size
+
+additionalProperties: false
+
+examples:

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml line 42

Quoted 6 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +6 -0

+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        nct7202@1d {

I think the Node name should follow

For some examples that were merged before

MAINTAINERS L: [email protected] (moderated for

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +5 -0

+            compatible = "nuvoton,nct7202";
+            reg = <0x1d>;
+            read-vin-data-size = <8>;
+        };
+    };

MAINTAINERS +0 -0

index 91d0609db61b..68570c58e7aa 100644
@@ -2746,6 +2746,7 @@ L:      [email protected] (moderated for

Quoted 7 lines

MAINTAINERS +1 -0

  S:  Supported
  F:  Documentation/devicetree/bindings/*/*/*npcm*
  F:  Documentation/devicetree/bindings/*/*npcm*
+F:   Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml
  F:  Documentation/devicetree/bindings/rtc/nuvoton,nct3018y.yaml
  F:  arch/arm/boot/dts/nuvoton/nuvoton-npcm*
  F:  arch/arm/mach-npcm/

This adds a binding specification for the Nuvoton NCT7201/NCT7202 family of ADCs.

Signed-off-by Eason Yang <[email protected]>

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +22 -0

@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/nuvoton,nct720x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Nuvoton nct7202 and similar ADCs
+
+maintainers:
+  - Eason Yang <[email protected]>
+
+description: |
+   Family of ADCs with i2c interface.
+
+properties:
+  compatible:
+    enum:
+      - nuvoton,nct7201
+      - nuvoton,nct7202
+
+  reg:
+    maxItems: 1

Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml new file +15 -0

+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        nct7202@1d {
+            compatible = "nuvoton,nct7202";
+            reg = <0x1d>;
+            read-vin-data-size = <8>;
+        };
+    };

MAINTAINERS +1 -0

index 91d0609db61b..68570c58e7aa 100644
@@ -2746,6 +2746,7 @@ L:	[email protected] (moderated for non-subscribers)
 S:	Supported
 F:	Documentation/devicetree/bindings/*/*/*npcm*
 F:	Documentation/devicetree/bindings/*/*npcm*
+F:	Documentation/devicetree/bindings/iio/adc/nuvoton,nct720x.yaml
 F:	Documentation/devicetree/bindings/rtc/nuvoton,nct3018y.yaml
 F:	arch/arm/boot/dts/nuvoton/nuvoton-npcm*
 F:	arch/arm/mach-npcm/

Hi Eason,

kernel test robot noticed the following build warnings:

[auto build test WARNING on jic23-iio/togreg]
[also build test WARNING on linus/master v6.12-rc6 next-20241106] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Eason-Yang/dt-bindings-iio-adc-Add-binding-for-Nuvoton-NCT720x-ADCs/20241106-104046
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg
patch link:    https://lore.kernel.org/r/20241106023916.440767-3-j2anfernee%40gmail.com
patch subject: [PATCH v1 2/2] iio: adc: add Nuvoton NCT720x ADC driver
config: s390-allmodconfig (https://download.01.org/0day-ci/archive/20241106/[email protected]/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 592c0fe55f6d9a811028b5f3507be91458ab2713)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241106/[email protected]/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/

All warnings (new ones prefixed by >>):

In file included from drivers/iio/adc/nct720x.c:9:
In file included from include/linux/device.h:32:
In file included from include/linux/device/driver.h:21:
In file included from include/linux/module.h:19:
In file included from include/linux/elf.h:6:
In file included from arch/s390/include/asm/elf.h:181:
In file included from arch/s390/include/asm/mmu_context.h:11:
In file included from arch/s390/include/asm/pgalloc.h:18:
In file included from include/linux/mm.h:2213:
include/linux/vmstat.h:504:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]

     504 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     505 |                            item];
         |                            ~~~~
   include/linux/vmstat.h:511:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     511 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     512 |                            NR_VM_NUMA_EVENT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~~
   include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     518 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
   include/linux/vmstat.h:524:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     524 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     525 |                            NR_VM_NUMA_EVENT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~~

Quoted 1 line

Quoted 1 line

drivers/iio/adc/nct720x.c:526:16: warning: cast to smaller integer type 'enum nct720x_chips' from 'const void *' [-Wvoid-pointer-to-enum-cast]

     526 |                 chip->type = (enum nct720x_chips)device_get_match_data(&client->dev);
         |                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

5 warnings generated.

vim +526 drivers/iio/adc/nct720x.c

   511
   512  static int nct720x_probe(struct i2c_client *client)
   513  {
   514          const struct i2c_device_id *id = i2c_client_get_device_id(client);
   515          struct nct720x_chip_info *chip;
   516          struct iio_dev *indio_dev;
   517          int ret;
   518          u32 tmp;
   519
   520          indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
   521          if (!indio_dev)
   522                  return -ENOMEM;
   523          chip = iio_priv(indio_dev);
   524
   525          if (client->dev.of_node)

Quoted 1 line

526 chip->type = (enum nct720x_chips)device_get_match_data(&client->dev);

527 else

   528                  chip->type = i2c_match_id(nct720x_id, client)->driver_data;
   529
   530          chip->vin_max = (chip->type == nct7201) ? NCT7201_VIN_MAX : NCT7202_VIN_MAX;
   531
   532          ret = of_property_read_u32(client->dev.of_node, "read-vin-data-size", &tmp);
   533          if (ret < 0) {
   534                  pr_err("read-vin-data-size property not found\n");
   535                  return ret;
   536          }
   537
   538          if (tmp == 8) {
   539                  chip->use_read_byte_vin = true;
   540          } else if (tmp == 16) {
   541                  chip->use_read_byte_vin = false;
   542          } else {
   543                  pr_err("invalid read-vin-data-size (%d)\n", tmp);
   544                  return -EINVAL;
   545          }
   546
   547          mutex_init(&chip->access_lock);
   548
   549          /* this is only used for device removal purposes */
   550          i2c_set_clientdata(client, indio_dev);
   551
   552          chip->client = client;
   553
   554          ret = nct720x_init_chip(chip);
   555          if (ret < 0)
   556                  return ret;
   557
   558          indio_dev->name = id->name;
   559          indio_dev->channels = nct720x_channels;
   560          indio_dev->num_channels = ARRAY_SIZE(nct720x_channels);
   561          indio_dev->info = &nct720x_info;
   562          indio_dev->modes = INDIO_DIRECT_MODE;
   563
   564          iio_device_register(indio_dev);
   565
   566          return 0;
   567  }
   568

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Add Nuvoton NCT7201/NCT7202 system voltage monitor 12-bit ADC driver

NCT7201/NCT7202 supports up to 12 analog voltage monitor inputs and up to 4 SMBus addresses by ADDR pin. Meanwhile, ALERT# hardware event pins for independent alarm signals, and the all threshold values could be set for system protection without any timing delay. It also supports reset input RSTIN# to recover system from a fault condition.

Currently, only single-edge mode conversion and threshold events support.

Signed-off-by Eason Yang <[email protected]>

drivers/iio/adc/nct720x.c new file +8 -0

+
+static int nct720x_probe(struct i2c_client *client)
+{
+	const struct i2c_device_id *id = i2c_client_get_device_id(client);
+	struct nct720x_chip_info *chip;
+	struct iio_dev *indio_dev;
+	int ret;
+	u32 tmp;

Quoted 11 lines

Add Nuvoton NCT7201/NCT7202 system voltage monitor 12-bit ADC driver

NCT7201/NCT7202 supports up to 12 analog voltage monitor inputs and up to 4 SMBus addresses by ADDR pin. Meanwhile, ALERT# hardware event pins for independent alarm signals, and the all threshold values could be set for system protection without any timing delay. It also supports reset input RSTIN# to recover system from a fault condition.

Currently, only single-edge mode conversion and threshold events support.

Signed-off-by Eason Yang <[email protected]>

...

Quoted 12 lines

drivers/iio/adc/nct720x.c new file +12 -0

+
+static int nct720x_probe(struct i2c_client *client)
+{
+     const struct i2c_device_id *id = i2c_client_get_device_id(client);
+     struct nct720x_chip_info *chip;
+     struct iio_dev *indio_dev;
+     int ret;
+     u32 tmp;
+
+     indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
+     if (!indio_dev)
+             return -ENOMEM;

drivers/iio/adc/nct720x.c line 528

Quoted 6 lines

drivers/iio/adc/nct720x.c new file +6 -0

+     chip = iio_priv(indio_dev);
+
+     if (client->dev.of_node)
+             chip->type = (enum nct720x_chips)device_get_match_data(&client->dev);
+     else
+             chip->type = i2c_match_id(nct720x_id, client)->driver_data;

I believe there is a I2C wrapper for above.

drivers/iio/adc/nct720x.c line 534

Quoted 6 lines

drivers/iio/adc/nct720x.c new file +6 -0

+
+     chip->vin_max = (chip->type == nct7201) ? NCT7201_VIN_MAX : NCT7202_VIN_MAX;
+
+     ret = of_property_read_u32(client->dev.of_node, "read-vin-data-size", &tmp);
+     if (ret < 0) {
+             pr_err("read-vin-data-size property not found\n");

Please use dev_xxx in your driver code.

Best regards,
Krzysztof

Dear Krzysztof Kozlowski,

Thank you for your response.

Krzysztof Kozlowski <[email protected]> 於 2024年11月6日 週三 下午9:41寫道：

Quoted 28 lines · Eason Yang

Quoted 11 lines

Add Nuvoton NCT7201/NCT7202 system voltage monitor 12-bit ADC driver

NCT7201/NCT7202 supports up to 12 analog voltage monitor inputs and up to 4 SMBus addresses by ADDR pin. Meanwhile, ALERT# hardware event pins for independent alarm signals, and the all threshold values could be set for system protection without any timing delay. It also supports reset input RSTIN# to recover system from a fault condition.

Currently, only single-edge mode conversion and threshold events support.

Signed-off-by Eason Yang <[email protected]>

...

Quoted 12 lines

drivers/iio/adc/nct720x.c new file +12 -0

+
+static int nct720x_probe(struct i2c_client *client)
+{
+     const struct i2c_device_id *id = i2c_client_get_device_id(client);
+     struct nct720x_chip_info *chip;
+     struct iio_dev *indio_dev;
+     int ret;
+     u32 tmp;
+
+     indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
+     if (!indio_dev)
+             return -ENOMEM;

Quoted 9 lines

drivers/iio/adc/nct720x.c line 528

Quoted 6 lines

drivers/iio/adc/nct720x.c new file +6 -0

+     chip = iio_priv(indio_dev);
+
+     if (client->dev.of_node)
+             chip->type = (enum nct720x_chips)device_get_match_data(&client->dev);
+     else
+             chip->type = i2c_match_id(nct720x_id, client)->driver_data;  

I believe there is a I2C wrapper for above.

Got it.

Quoted 9 lines

drivers/iio/adc/nct720x.c line 534

Quoted 7 lines

drivers/iio/adc/nct720x.c new file +6 -0

+
+     chip->vin_max = (chip->type == nct7201) ? NCT7201_VIN_MAX : NCT7202_VIN_MAX;
+
+     ret = of_property_read_u32(client->dev.of_node, "read-vin-data-size", &tmp);
+     if (ret < 0) {
+             pr_err("read-vin-data-size property not found\n");  

Please use dev_xxx in your driver code.

Got it.

Quoted 5 lines

Best regards,
Krzysztof

Quoted 43 lines · On Thu, 7 Nov 2024 08:41:21 +0800 Yu-Hsian Yang <[email protected]> wrote:

Dear Krzysztof Kozlowski,

Thank you for your response.

Krzysztof Kozlowski <[email protected]> 於 2024年11月6日 週三 下午9:41寫道：

Quoted 37 lines · Eason Yang

Quoted 11 lines

Add Nuvoton NCT7201/NCT7202 system voltage monitor 12-bit ADC driver

NCT7201/NCT7202 supports up to 12 analog voltage monitor inputs and up to 4 SMBus addresses by ADDR pin. Meanwhile, ALERT# hardware event pins for independent alarm signals, and the all threshold values could be set for system protection without any timing delay. It also supports reset input RSTIN# to recover system from a fault condition.

Currently, only single-edge mode conversion and threshold events support.

Signed-off-by Eason Yang <[email protected]>

...

Quoted 8 lines

drivers/iio/adc/nct720x.c new file +8 -0

+
+static int nct720x_probe(struct i2c_client *client)
+{
+     const struct i2c_device_id *id = i2c_client_get_device_id(client);
+     struct nct720x_chip_info *chip;
+     struct iio_dev *indio_dev;
+     int ret;
+     u32 tmp;

drivers/iio/adc/nct720x.c line 528

Quoted 10 lines

drivers/iio/adc/nct720x.c new file +10 -0

+
+     indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
+     if (!indio_dev)
+             return -ENOMEM;
+     chip = iio_priv(indio_dev);
+
+     if (client->dev.of_node)
+             chip->type = (enum nct720x_chips)device_get_match_data(&client->dev);
+     else
+             chip->type = i2c_match_id(nct720x_id, client)->driver_data;

I believe there is a I2C wrapper for above.

Quoted 1 line

Got it.

Don't pass an enum value as data. Pass a pointer to a structure that describes the particular variant. The 0 value which tends to end up in enums is an error for device_get_match_data.

Quoted 17 lines

Quoted 9 lines

drivers/iio/adc/nct720x.c line 534

Quoted 7 lines

drivers/iio/adc/nct720x.c new file +6 -0

+
+     chip->vin_max = (chip->type == nct7201) ? NCT7201_VIN_MAX : NCT7202_VIN_MAX;
+
+     ret = of_property_read_u32(client->dev.of_node, "read-vin-data-size", &tmp);
+     if (ret < 0) {
+             pr_err("read-vin-data-size property not found\n");

Please use dev_xxx in your driver code.

Got it.

Quoted 5 lines

Best regards,
Krzysztof

Add Nuvoton NCT7201/NCT7202 system voltage monitor 12-bit ADC driver

NCT7201/NCT7202 supports up to 12 analog voltage monitor inputs and up to 4 SMBus addresses by ADDR pin. Meanwhile, ALERT# hardware event pins for independent alarm signals, and the all threshold values could be set for system protection without any timing delay. It also supports reset input RSTIN# to recover system from a fault condition.

Currently, only single-edge mode conversion and threshold events support.

Signed-off-by Eason Yang <[email protected]>

---
 MAINTAINERS               |   1 +
 drivers/iio/adc/Kconfig   |   9 +
 drivers/iio/adc/Makefile  |   1 +
 drivers/iio/adc/nct720x.c | 617 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 628 insertions(+)
 create mode 100644 drivers/iio/adc/nct720x.c

MAINTAINERS +1 -0

index 68570c58e7aa..9940de0ddca2 100644
@@ -2753,6 +2753,7 @@ F:        arch/arm/mach-npcm/
 F:     arch/arm64/boot/dts/nuvoton/
 F:     drivers/*/*/*npcm*
 F:     drivers/*/*npcm*
+F:     drivers/iio/adc/nct720x.c
 F:     drivers/rtc/rtc-nct3018y.c
 F:     include/dt-bindings/clock/nuvoton,npcm7xx-clock.h
 F:     include/dt-bindings/clock/nuvoton,npcm845-clk.h

drivers/iio/adc/Kconfig +9 -0

index 6c4e74420fd2..adbbf0ca6f57 100644
@@ -1008,6 +1008,15 @@ config NAU7802
          To compile this driver as a module, choose M here: the
          module will be called nau7802.
 
+config NCT720X
+       tristate "Nuvoton Instruments NCT7201 and NCT7202 Power Monitor"
+       depends on I2C
+       help
+         If you say yes here you get support for the Nuvoton NCT7201 and
+         NCT7202 Voltage Monitor.
+         This driver can also be built as a module. If so, the module
+         will be called nct720x.
+
 config NPCM_ADC
        tristate "Nuvoton NPCM ADC driver"
        depends on ARCH_NPCM || COMPILE_TEST

drivers/iio/adc/Makefile +1 -0

index 7b91cd98c0e0..f53318e5aa04 100644
@@ -91,6 +91,7 @@ obj-$(CONFIG_MESON_SARADC) += meson_saradc.o
 obj-$(CONFIG_MP2629_ADC) += mp2629_adc.o
 obj-$(CONFIG_MXS_LRADC_ADC) += mxs-lradc-adc.o
 obj-$(CONFIG_NAU7802) += nau7802.o
+obj-$(CONFIG_NCT720X) += nct720x.o
 obj-$(CONFIG_NPCM_ADC) += npcm_adc.o
 obj-$(CONFIG_PAC1921) += pac1921.o
 obj-$(CONFIG_PAC1934) += pac1934.o

drivers/iio/adc/nct720x.c new file +393 -0

new file mode 100644
index 000000000000..e589479fd06e
@@ -0,0 +1,617 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Driver for Nuvoton nct7201 and nct7202 power monitor chips.
+ *
+ * Copyright (c) 2022 Nuvoton Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+
+#define REG_CHIP_ID                    0xFD
+#define NCT720X_ID                     0xD7
+#define REG_VENDOR_ID                  0xFE
+#define NUVOTON_ID                     0x50
+#define REG_DEVICE_ID                  0xFF
+#define NCT720X_DEVICE_ID              0x12
+#define VIN_MAX                                12      /* Counted from 1 */
+#define NCT7201_VIN_MAX                        8
+#define NCT7202_VIN_MAX                        12
+#define NCT720X_IN_SCALING             4995
+
+#define REG_INTERRUPT_STATUS_1         0x0C
+#define REG_INTERRUPT_STATUS_2         0x0D
+#define REG_VOLT_LOW_BYTE              0x0F
+#define REG_CONFIGURATION              0x10
+#define  CONFIGURATION_START           BIT(0)
+#define  CONFIGURATION_ALERT_MSK       BIT(1)
+#define  CONFIGURATION_CONV_RATE       BIT(2)
+#define  CONFIGURATION_INIT            BIT(7)
+
+#define REG_ADVANCED_CONFIGURATION     0x11
+#define  ADVANCED_CONF_MOD_ALERT       BIT(0)
+#define  ADVANCED_CONF_MOD_STS         BIT(1)
+#define  ADVANCED_CONF_FAULT_QUEUE     BIT(2)
+#define  ADVANCED_CONF_EN_DEEP_SHUTDOWN        BIT(4)
+#define  ADVANCED_CONF_EN_SMB_TIMEOUT  BIT(5)
+#define  ADVANCED_CONF_MOD_RSTIN       BIT(7)
+
+#define REG_CHANNEL_INPUT_MODE         0x12
+#define REG_CHANNEL_ENABLE_1           0x13
+#define REG_CHANNEL_ENABLE_2           0x14
+#define REG_INTERRUPT_MASK_1           0x15
+#define REG_INTERRUPT_MASK_2           0x16
+#define REG_BUSY_STATUS                        0x1E
+#define REG_ONE_SHOT                   0x1F
+#define REG_SMUS_ADDRESS               0xFC
+
+static const u8 REG_VIN[VIN_MAX] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05,
+                                    0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B};
+static const u8 REG_VIN_HIGH_LIMIT[VIN_MAX] = { 0x20, 0x22, 0x24, 0x26, 0x28, 0x2A,
+                                               0x2C, 0x2E, 0x30, 0x32, 0x34, 0x36};
+static const u8 REG_VIN_LOW_LIMIT[VIN_MAX] = { 0x21, 0x23, 0x25, 0x27, 0x29, 0x2B,
+                                              0x2D, 0x2F, 0x31, 0x33, 0x35, 0x37};
+static const u8 REG_VIN_HIGH_LIMIT_LSB[VIN_MAX] = { 0x40, 0x42, 0x44, 0x46, 0x48, 0x4A,
+                                                   0x4C, 0x4E, 0x50, 0x52, 0x54, 0x56};
+static const u8 REG_VIN_LOW_LIMIT_LSB[VIN_MAX] = { 0x41, 0x43, 0x45, 0x47, 0x49, 0x4B,
+                                                  0x4D, 0x4F, 0x51, 0x53, 0x55, 0x57};
+static u8 nct720x_chan_to_index[] = {
+       0,      /* Not used */
+       0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
+};
+
+
+/* List of supported devices */
+enum nct720x_chips {
+       nct7201, nct7202
+};
+
+struct nct720x_chip_info {
+       struct i2c_client       *client;
+       enum nct720x_chips      type;
+       struct mutex            access_lock;    /* for multi-byte read and write operations */
+       int vin_max;                            /* number of VIN channels */
+       u32 vin_mask;
+       bool use_read_byte_vin;
+};
+
+static const struct iio_event_spec nct720x_events[] = {
+       {
+               .type = IIO_EV_TYPE_THRESH,
+               .dir = IIO_EV_DIR_RISING,
+               .mask_separate = BIT(IIO_EV_INFO_VALUE) |
+                                BIT(IIO_EV_INFO_ENABLE),
+       }, {
+               .type = IIO_EV_TYPE_THRESH,
+               .dir = IIO_EV_DIR_FALLING,
+               .mask_separate = BIT(IIO_EV_INFO_VALUE) |
+                                BIT(IIO_EV_INFO_ENABLE),
+       },
+};
+
+#define NCT720X_VOLTAGE_CHANNEL(chan, addr)                            \
+       {                                                               \
+               .type = IIO_VOLTAGE,                                    \
+               .indexed = 1,                                           \
+               .channel = chan,                                        \
+               .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),     \
+               .address = addr,                                        \
+               .event_spec = nct720x_events,                           \
+               .num_event_specs = ARRAY_SIZE(nct720x_events),          \
+       }
+
+#define NCT720X_VOLTAGE_CHANNEL_DIFF(chan1, chan2, addr)               \
+       {                                                               \
+               .type = IIO_VOLTAGE,                                    \
+               .indexed = 1,                                           \
+               .channel = (chan1),                                     \
+               .channel2 = (chan2),                                    \
+               .differential = 1,                                      \
+               .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),     \
+               .address = addr,                                        \
+               .event_spec = nct720x_events,                           \
+               .num_event_specs = ARRAY_SIZE(nct720x_events),          \
+       }
+
+static const struct iio_chan_spec nct720x_channels[] = {
+       NCT720X_VOLTAGE_CHANNEL(1, 1),
+       NCT720X_VOLTAGE_CHANNEL(2, 2),
+       NCT720X_VOLTAGE_CHANNEL(3, 3),
+       NCT720X_VOLTAGE_CHANNEL(4, 4),
+       NCT720X_VOLTAGE_CHANNEL(5, 5),
+       NCT720X_VOLTAGE_CHANNEL(6, 6),
+       NCT720X_VOLTAGE_CHANNEL(7, 7),
+       NCT720X_VOLTAGE_CHANNEL(8, 8),
+       NCT720X_VOLTAGE_CHANNEL(9, 9),
+       NCT720X_VOLTAGE_CHANNEL(10, 10),
+       NCT720X_VOLTAGE_CHANNEL(11, 11),
+       NCT720X_VOLTAGE_CHANNEL(12, 12),
+       NCT720X_VOLTAGE_CHANNEL_DIFF(1, 2, 1),
+       NCT720X_VOLTAGE_CHANNEL_DIFF(3, 4, 3),
+       NCT720X_VOLTAGE_CHANNEL_DIFF(5, 6, 5),
+       NCT720X_VOLTAGE_CHANNEL_DIFF(7, 8, 7),
+       NCT720X_VOLTAGE_CHANNEL_DIFF(9, 10, 9),
+       NCT720X_VOLTAGE_CHANNEL_DIFF(11, 12, 11),
+};
+
+/* Read 1-byte register. Returns unsigned byte data or -ERRNO on error. */
+static int nct720x_read_reg(struct nct720x_chip_info *chip, u8 reg)
+{
+       struct i2c_client *client = chip->client;
+
+       return i2c_smbus_read_byte_data(client, reg);
+}
+
+/* Read 1-byte register. Returns unsigned word data or -ERRNO on error. */
+static int nct720x_read_word_swapped_reg(struct nct720x_chip_info *chip, u8 reg)
+{
+       struct i2c_client *client = chip->client;
+
+       return i2c_smbus_read_word_swapped(client, reg);
+}
+
+/*
+ * Read 2-byte register. Returns register in big-endian format or
+ * -ERRNO on error.
+ */
+static int nct720x_read_reg16(struct nct720x_chip_info *chip, u8 reg)
+{
+       struct i2c_client *client = chip->client;
+       int ret, low;
+
+       mutex_lock(&chip->access_lock);
+       ret = i2c_smbus_read_byte_data(client, reg);
+       if (ret >= 0) {
+               low = ret;
+               ret = i2c_smbus_read_byte_data(client, reg + 1);
+               if (ret >= 0)
+                       ret = low | (ret << 8);
+       }
+
+       mutex_unlock(&chip->access_lock);
+       return ret;
+}
+
+/* Write 1-byte register. Returns 0 or -ERRNO on error. */
+static int nct720x_write_reg(struct nct720x_chip_info *chip, u8 reg, u8 val)
+{
+       struct i2c_client *client = chip->client;
+       int err;
+
+       err = i2c_smbus_write_byte_data(client, reg, val);
+       /* wait for write command to be finished */
+       mdelay(10);
+
+       return err;
+}
+
+static int nct720x_read_raw(struct iio_dev *indio_dev,
+                           struct iio_chan_spec const *chan,
+                           int *val, int *val2, long mask)
+{
+       int index = nct720x_chan_to_index[chan->address];
+       int v1, v2, volt, err;
+       struct nct720x_chip_info *chip = iio_priv(indio_dev);
+
+       if (chan->type != IIO_VOLTAGE)
+               return -EOPNOTSUPP;
+
+       switch (mask) {
+       case IIO_CHAN_INFO_PROCESSED:
+               mutex_lock(&chip->access_lock);
+               if (chip->use_read_byte_vin) {
+                       /*
+                        * MNTVIN Low Byte together with MNTVIN High Byte
+                        * forms the 13-bit count value. If MNTVIN High
+                        * Byte readout is read successively, the
+                        * NCT7201/NCT7202 will latch the MNTVIN Low Byte
+                        * for next read.
+                        */
+                       v1 = nct720x_read_reg(chip, REG_VIN[index]);
+                       if (v1 < 0) {
+                               err = v1;
+                               goto abort;
+                       }
+
+                       v2 = nct720x_read_reg(chip, REG_VOLT_LOW_BYTE);
+                       if (v2 < 0) {
+                               err = v2;
+                               goto abort;
+                       }
+                       volt = (v1 << 8) | v2;  /* Convert back to 16-bit value */
+               } else {
+                       /* NCT7201/NCT7202 also supports read word-size data */
+                       volt = nct720x_read_word_swapped_reg(chip, REG_VIN[index]);
+               }
+
+               /* Voltage(V) = 13bitCountValue * 0.0004995 */
+               volt = (volt >> 3) * NCT720X_IN_SCALING;
+               *val = volt / 10000;
+               mutex_unlock(&chip->access_lock);
+               return IIO_VAL_INT;
+       default:
+               return -EINVAL;
+       }
+abort:
+       mutex_unlock(&chip->access_lock);
+       return err;
+}
+
+static int nct720x_read_event_value(struct iio_dev *indio_dev,
+                                   const struct iio_chan_spec *chan,
+                                   enum iio_event_type type,
+                                   enum iio_event_direction dir,
+                                   enum iio_event_info info,
+                                   int *val, int *val2)
+{
+       struct nct720x_chip_info *chip = iio_priv(indio_dev);
+       int v1, v2, err;
+       int volt = 0;
+       int index = nct720x_chan_to_index[chan->address];
+
+       if (chan->type != IIO_VOLTAGE)
+               return -EOPNOTSUPP;
+
+       if (info == IIO_EV_INFO_VALUE) {
+               if (dir == IIO_EV_DIR_FALLING) {
+                       if (chip->use_read_byte_vin) {
+                               /*
+                                * Low limit VIN Low Byte together with Low limit VIN High Byte
+                                  forms the 13-bit count value
+                                */
+                               mutex_lock(&chip->access_lock);
+                               v1 = nct720x_read_reg(chip, REG_VIN_LOW_LIMIT[index]);
+                               if (v1 < 0) {
+                                       err = v1;
+                                       goto abort;
+                               }
+
+                               v2 = nct720x_read_reg(chip, REG_VIN_LOW_LIMIT_LSB[index]);
+                               if (v2 < 0) {
+                                       err = v2;
+                                       goto abort;
+                               }
+                               mutex_unlock(&chip->access_lock);
+                               volt = (v1 << 8) | v2;  /* Convert back to 16-bit value */
+                       } else {
+                               /* NCT7201/NCT7202 also supports read word-size data */
+                               volt = nct720x_read_word_swapped_reg(chip,
+                                       REG_VIN_LOW_LIMIT[index]);
+                       }
+               } else {
+                       if (chip->use_read_byte_vin) {
+                               /*
+                                * High limit VIN Low Byte together with high limit VIN High Byte
+                                * forms the 13-bit count value
+                                */
+                               mutex_lock(&chip->access_lock);
+                               v1 = nct720x_read_reg(chip, REG_VIN_HIGH_LIMIT[index]);
+                               if (v1 < 0) {
+                                       err = v1;
+                                       goto abort;
+                               }
+
+                               v2 = nct720x_read_reg(chip, REG_VIN_HIGH_LIMIT_LSB[index]);
+                               if (v2 < 0) {
+                                       err = v2;
+                                       goto abort;
+                               }
+                               mutex_unlock(&chip->access_lock);
+                               volt = (v1 << 8) | v2;  /* Convert back to 16-bit value */
+                       } else {
+                               /* NCT7201/NCT7202 also supports read word-size data */
+                               volt = nct720x_read_word_swapped_reg(chip,
+                                       REG_VIN_HIGH_LIMIT[index]);
+                       }
+               }
+       }
+       /* Voltage(V) = 13bitCountValue * 0.0004995 */
+       volt = (volt >> 3) * NCT720X_IN_SCALING;
+       *val = volt / 10000;
+
+       return IIO_VAL_INT;
+abort:
+       mutex_unlock(&chip->access_lock);
+       return err;
+}
+
+static int nct720x_write_event_value(struct iio_dev *indio_dev,
+                                    const struct iio_chan_spec *chan,
+                                    enum iio_event_type type,
+                                    enum iio_event_direction dir,
+                                    enum iio_event_info info,
+                                    int val, int val2)
+{
+       struct nct720x_chip_info *chip = iio_priv(indio_dev);
+       int index, err = 0;
+       long v1, v2, volt;
+
+       index = nct720x_chan_to_index[chan->address];
+       volt = (val * 10000) / NCT720X_IN_SCALING;
+       v1 = volt >> 5;
+       v2 = (volt & 0x1f) << 3;
+
+       if (chan->type != IIO_VOLTAGE)
+               return -EOPNOTSUPP;
+
+       if (info == IIO_EV_INFO_VALUE) {
+               if (dir == IIO_EV_DIR_FALLING) {
+                       mutex_lock(&chip->access_lock);
+                       err = nct720x_write_reg(chip, REG_VIN_LOW_LIMIT[index], v1);
+                       if (err < 0) {
+                               pr_err("Failed to write REG_VIN%d_LOW_LIMIT\n", index + 1);
+                               goto abort;
+                       }
+
+                       err = nct720x_write_reg(chip, REG_VIN_LOW_LIMIT_LSB[index], v2);
+                       if (err < 0) {
+                               pr_err("Failed to write REG_VIN%d_LOW_LIMIT_LSB\n", index + 1);
+                               goto abort;
+                       }
+               } else {
+                       mutex_lock(&chip->access_lock);
+                       err = nct720x_write_reg(chip, REG_VIN_HIGH_LIMIT[index], v1);
+                       if (err < 0) {
+                               pr_err("Failed to write REG_VIN%d_HIGH_LIMIT\n", index + 1);
+                               goto abort;
+                       }
+
+                       err = nct720x_write_reg(chip, REG_VIN_HIGH_LIMIT_LSB[index], v2);
+                       if (err < 0) {
+                               pr_err("Failed to write REG_VIN%d_HIGH_LIMIT_LSB\n", index + 1);
+                               goto abort;
+                       }
+               }
+       }
+abort:
+       mutex_unlock(&chip->access_lock);
+       return err;
+}
+
+static int nct720x_read_event_config(struct iio_dev *indio_dev,
+                                    const struct iio_chan_spec *chan,
+                                    enum iio_event_type type,
+                                    enum iio_event_direction dir)
+{
+       struct nct720x_chip_info *chip = iio_priv(indio_dev);
+       int index = nct720x_chan_to_index[chan->address];
+
+       if (chan->type != IIO_VOLTAGE)
+               return -EOPNOTSUPP;
+
+       return !!(chip->vin_mask & BIT(index));
+}
+
+static int nct720x_write_event_config(struct iio_dev *indio_dev,
+                                     const struct iio_chan_spec *chan,

drivers/iio/adc/nct720x.c new file +53 -0

+
+       if (chan->type != IIO_VOLTAGE)
+               return -EOPNOTSUPP;
+
+       if (!state && (chip->vin_mask & mask))
+               chip->vin_mask &= ~mask;
+       else if (state && !(chip->vin_mask & mask))
+               chip->vin_mask |= mask;
+
+       mutex_lock(&chip->access_lock);
+
+       err = nct720x_write_reg(chip, REG_CHANNEL_ENABLE_1, chip->vin_mask & 0xff);
+       if (err < 0) {
+               pr_err("Failed to write REG_CHANNEL_ENABLE_1\n");
+               goto abort;
+       }
+
+       if (chip->type == nct7202) {
+               err = nct720x_write_reg(chip, REG_CHANNEL_ENABLE_2, chip->vin_mask >> 8);
+               if (err < 0) {
+                       pr_err("Failed to write REG_CHANNEL_ENABLE_2\n");
+                       goto abort;
+               }
+       }
+abort:
+       mutex_unlock(&chip->access_lock);
+       return err;
+}
+
+static int nct720x_detect(struct i2c_client *client,
+                         struct i2c_board_info *info)
+{
+       struct i2c_adapter *adapter = client->adapter;
+
+       if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+                                    I2C_FUNC_SMBUS_WORD_DATA))
+               return -ENODEV;
+
+       /* Determine the chip type. */
+       if (i2c_smbus_read_byte_data(client, REG_VENDOR_ID) != NUVOTON_ID ||
+           i2c_smbus_read_byte_data(client, REG_CHIP_ID) != NCT720X_ID ||
+           i2c_smbus_read_byte_data(client, REG_DEVICE_ID) != NCT720X_DEVICE_ID)
+               return -ENODEV;
+
+       strscpy(info->type, "nct720x", I2C_NAME_SIZE);
+
+       return 0;
+}
+
+static const struct iio_info nct720x_info = {
+       .read_raw = &nct720x_read_raw,
+       .read_event_config = &nct720x_read_event_config,
+       .write_event_config = &nct720x_write_event_config,

drivers/iio/adc/nct720x.c new file +59 -0

+
+       /* Initial reset */
+       err = nct720x_write_reg(chip, REG_CONFIGURATION, CONFIGURATION_INIT);
+       if (err) {
+               pr_err("Failed to write REG_CONFIGURATION\n");
+               return err;
+       }
+
+       /* Enable Channel */
+       err = nct720x_write_reg(chip, REG_CHANNEL_ENABLE_1, 0xff);
+       if (err) {
+               pr_err("Failed to write REG_CHANNEL_ENABLE_1\n");
+               return err;
+       }
+
+       if (chip->type == nct7202) {
+               err = nct720x_write_reg(chip, REG_CHANNEL_ENABLE_2, 0xf);
+               if (err) {
+                       pr_err("Failed to write REG_CHANNEL_ENABLE_2\n");
+                       return err;
+               }
+       }
+
+       value = nct720x_read_reg16(chip, REG_CHANNEL_ENABLE_1);
+       if (value < 0)
+               return value;
+       chip->vin_mask = value;
+
+       /* Start monitoring if needed */
+       value = nct720x_read_reg(chip, REG_CONFIGURATION);
+       if (value < 0) {
+               pr_err("Failed to read REG_CONFIGURATION\n");
+               return value;
+       }
+
+       value |= CONFIGURATION_START;
+       err = nct720x_write_reg(chip, REG_CONFIGURATION, value);
+       if (err < 0) {
+               pr_err("Failed to write REG_CONFIGURATION\n");
+               return err;
+       }
+
+       return 0;
+}
+
+static int nct720x_probe(struct i2c_client *client)
+{
+       const struct i2c_device_id *id = i2c_client_get_device_id(client);
+       struct nct720x_chip_info *chip;
+       struct iio_dev *indio_dev;
+       int ret;
+       u32 tmp;
+
+       indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
+       if (!indio_dev)
+               return -ENOMEM;
+       chip = iio_priv(indio_dev);
+
+       if (client->dev.of_node)

drivers/iio/adc/nct720x.c new file +10 -0

+       }
+
+       mutex_init(&chip->access_lock);
+
+       /* this is only used for device removal purposes */
+       i2c_set_clientdata(client, indio_dev);
+
+       chip->client = client;
+
+       ret = nct720x_init_chip(chip);

drivers/iio/adc/nct720x.c new file +44 -1

+}
+
+static const unsigned short nct720x_address_list[] = {
+       0x1d, 0x1e, 0x35, 0x36, I2C_CLIENT_END
+};
+
+static const struct i2c_device_id nct720x_id[] = {
+       { "nct7201", nct7201 },
+       { "nct7202", nct7202 },
+       {}
+};
+MODULE_DEVICE_TABLE(i2c, nct720x_id);
+
+static const struct of_device_id nct720x_of_match[] = {
+       {
+               .compatible = "nuvoton,nct7201",
+               .data = (void *)nct7201
+       },
+       {
+               .compatible = "nuvoton,nct7202",
+               .data = (void *)nct7202
+       },
+       { },
+};
+
+MODULE_DEVICE_TABLE(of, nct720x_of_match);
+
+static struct i2c_driver nct720x_driver = {
+       .driver = {
+               .name   = "nct720x",
+               .of_match_table = nct720x_of_match,
+       },
+       .probe = nct720x_probe,
+       .remove = nct720x_remove,
+       .id_table = nct720x_id,
+       .detect = nct720x_detect,
+       .address_list = nct720x_address_list,
+};
+
+module_i2c_driver(nct720x_driver);
+
+MODULE_AUTHOR("Eason Yang <[email protected]>");
+MODULE_DESCRIPTION("Nuvoton NCT720x voltage monitor driver");
+MODULE_LICENSE("GPL");
--

2.34.1

Quoted 471 lines

Add Nuvoton NCT7201/NCT7202 system voltage monitor 12-bit ADC driver

NCT7201/NCT7202 supports up to 12 analog voltage monitor inputs and up to 4 SMBus addresses by ADDR pin. Meanwhile, ALERT# hardware event pins for independent alarm signals, and the all threshold values could be set for system protection without any timing delay. It also supports reset input RSTIN# to recover system from a fault condition.

Currently, only single-edge mode conversion and threshold events support.

Signed-off-by Eason Yang <[email protected]>

---
 MAINTAINERS               |   1 +
 drivers/iio/adc/Kconfig   |   9 +
 drivers/iio/adc/Makefile  |   1 +
 drivers/iio/adc/nct720x.c | 617 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 628 insertions(+)
 create mode 100644 drivers/iio/adc/nct720x.c

MAINTAINERS +1 -0

index 68570c58e7aa..9940de0ddca2 100644
@@ -2753,6 +2753,7 @@ F:        arch/arm/mach-npcm/
 F:     arch/arm64/boot/dts/nuvoton/
 F:     drivers/*/*/*npcm*
 F:     drivers/*/*npcm*
+F:     drivers/iio/adc/nct720x.c
 F:     drivers/rtc/rtc-nct3018y.c
 F:     include/dt-bindings/clock/nuvoton,npcm7xx-clock.h
 F:     include/dt-bindings/clock/nuvoton,npcm845-clk.h

drivers/iio/adc/Kconfig +9 -0

index 6c4e74420fd2..adbbf0ca6f57 100644
@@ -1008,6 +1008,15 @@ config NAU7802
          To compile this driver as a module, choose M here: the
          module will be called nau7802.
 
+config NCT720X
+       tristate "Nuvoton Instruments NCT7201 and NCT7202 Power Monitor"
+       depends on I2C
+       help
+         If you say yes here you get support for the Nuvoton NCT7201 and
+         NCT7202 Voltage Monitor.
+         This driver can also be built as a module. If so, the module
+         will be called nct720x.
+
 config NPCM_ADC
        tristate "Nuvoton NPCM ADC driver"
        depends on ARCH_NPCM || COMPILE_TEST

drivers/iio/adc/Makefile +1 -0

index 7b91cd98c0e0..f53318e5aa04 100644
@@ -91,6 +91,7 @@ obj-$(CONFIG_MESON_SARADC) += meson_saradc.o
 obj-$(CONFIG_MP2629_ADC) += mp2629_adc.o
 obj-$(CONFIG_MXS_LRADC_ADC) += mxs-lradc-adc.o
 obj-$(CONFIG_NAU7802) += nau7802.o
+obj-$(CONFIG_NCT720X) += nct720x.o
 obj-$(CONFIG_NPCM_ADC) += npcm_adc.o
 obj-$(CONFIG_PAC1921) += pac1921.o
 obj-$(CONFIG_PAC1934) += pac1934.o

drivers/iio/adc/nct720x.c new file +401 -0

new file mode 100644
index 000000000000..e589479fd06e
@@ -0,0 +1,617 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Driver for Nuvoton nct7201 and nct7202 power monitor chips.
+ *
+ * Copyright (c) 2022 Nuvoton Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+
+#define REG_CHIP_ID                    0xFD
+#define NCT720X_ID                     0xD7
+#define REG_VENDOR_ID                  0xFE
+#define NUVOTON_ID                     0x50
+#define REG_DEVICE_ID                  0xFF
+#define NCT720X_DEVICE_ID              0x12
+#define VIN_MAX                                12      /* Counted from 1 */
+#define NCT7201_VIN_MAX                        8
+#define NCT7202_VIN_MAX                        12
+#define NCT720X_IN_SCALING             4995
+
+#define REG_INTERRUPT_STATUS_1         0x0C
+#define REG_INTERRUPT_STATUS_2         0x0D
+#define REG_VOLT_LOW_BYTE              0x0F
+#define REG_CONFIGURATION              0x10
+#define  CONFIGURATION_START           BIT(0)
+#define  CONFIGURATION_ALERT_MSK       BIT(1)
+#define  CONFIGURATION_CONV_RATE       BIT(2)
+#define  CONFIGURATION_INIT            BIT(7)
+
+#define REG_ADVANCED_CONFIGURATION     0x11
+#define  ADVANCED_CONF_MOD_ALERT       BIT(0)
+#define  ADVANCED_CONF_MOD_STS         BIT(1)
+#define  ADVANCED_CONF_FAULT_QUEUE     BIT(2)
+#define  ADVANCED_CONF_EN_DEEP_SHUTDOWN        BIT(4)
+#define  ADVANCED_CONF_EN_SMB_TIMEOUT  BIT(5)
+#define  ADVANCED_CONF_MOD_RSTIN       BIT(7)
+
+#define REG_CHANNEL_INPUT_MODE         0x12
+#define REG_CHANNEL_ENABLE_1           0x13
+#define REG_CHANNEL_ENABLE_2           0x14
+#define REG_INTERRUPT_MASK_1           0x15
+#define REG_INTERRUPT_MASK_2           0x16
+#define REG_BUSY_STATUS                        0x1E
+#define REG_ONE_SHOT                   0x1F
+#define REG_SMUS_ADDRESS               0xFC
+
+static const u8 REG_VIN[VIN_MAX] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05,
+                                    0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B};
+static const u8 REG_VIN_HIGH_LIMIT[VIN_MAX] = { 0x20, 0x22, 0x24, 0x26, 0x28, 0x2A,
+                                               0x2C, 0x2E, 0x30, 0x32, 0x34, 0x36};
+static const u8 REG_VIN_LOW_LIMIT[VIN_MAX] = { 0x21, 0x23, 0x25, 0x27, 0x29, 0x2B,
+                                              0x2D, 0x2F, 0x31, 0x33, 0x35, 0x37};
+static const u8 REG_VIN_HIGH_LIMIT_LSB[VIN_MAX] = { 0x40, 0x42, 0x44, 0x46, 0x48, 0x4A,
+                                                   0x4C, 0x4E, 0x50, 0x52, 0x54, 0x56};
+static const u8 REG_VIN_LOW_LIMIT_LSB[VIN_MAX] = { 0x41, 0x43, 0x45, 0x47, 0x49, 0x4B,
+                                                  0x4D, 0x4F, 0x51, 0x53, 0x55, 0x57};
+static u8 nct720x_chan_to_index[] = {
+       0,      /* Not used */
+       0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
+};
+
+
+/* List of supported devices */
+enum nct720x_chips {
+       nct7201, nct7202
+};
+
+struct nct720x_chip_info {
+       struct i2c_client       *client;
+       enum nct720x_chips      type;
+       struct mutex            access_lock;    /* for multi-byte read and write operations */
+       int vin_max;                            /* number of VIN channels */
+       u32 vin_mask;
+       bool use_read_byte_vin;
+};
+
+static const struct iio_event_spec nct720x_events[] = {
+       {
+               .type = IIO_EV_TYPE_THRESH,
+               .dir = IIO_EV_DIR_RISING,
+               .mask_separate = BIT(IIO_EV_INFO_VALUE) |
+                                BIT(IIO_EV_INFO_ENABLE),
+       }, {
+               .type = IIO_EV_TYPE_THRESH,
+               .dir = IIO_EV_DIR_FALLING,
+               .mask_separate = BIT(IIO_EV_INFO_VALUE) |
+                                BIT(IIO_EV_INFO_ENABLE),
+       },
+};
+
+#define NCT720X_VOLTAGE_CHANNEL(chan, addr)                            \
+       {                                                               \
+               .type = IIO_VOLTAGE,                                    \
+               .indexed = 1,                                           \
+               .channel = chan,                                        \
+               .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),     \
+               .address = addr,                                        \
+               .event_spec = nct720x_events,                           \
+               .num_event_specs = ARRAY_SIZE(nct720x_events),          \
+       }
+
+#define NCT720X_VOLTAGE_CHANNEL_DIFF(chan1, chan2, addr)               \
+       {                                                               \
+               .type = IIO_VOLTAGE,                                    \
+               .indexed = 1,                                           \
+               .channel = (chan1),                                     \
+               .channel2 = (chan2),                                    \
+               .differential = 1,                                      \
+               .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),     \
+               .address = addr,                                        \
+               .event_spec = nct720x_events,                           \
+               .num_event_specs = ARRAY_SIZE(nct720x_events),          \
+       }
+
+static const struct iio_chan_spec nct720x_channels[] = {
+       NCT720X_VOLTAGE_CHANNEL(1, 1),
+       NCT720X_VOLTAGE_CHANNEL(2, 2),
+       NCT720X_VOLTAGE_CHANNEL(3, 3),
+       NCT720X_VOLTAGE_CHANNEL(4, 4),
+       NCT720X_VOLTAGE_CHANNEL(5, 5),
+       NCT720X_VOLTAGE_CHANNEL(6, 6),
+       NCT720X_VOLTAGE_CHANNEL(7, 7),
+       NCT720X_VOLTAGE_CHANNEL(8, 8),
+       NCT720X_VOLTAGE_CHANNEL(9, 9),
+       NCT720X_VOLTAGE_CHANNEL(10, 10),
+       NCT720X_VOLTAGE_CHANNEL(11, 11),
+       NCT720X_VOLTAGE_CHANNEL(12, 12),
+       NCT720X_VOLTAGE_CHANNEL_DIFF(1, 2, 1),
+       NCT720X_VOLTAGE_CHANNEL_DIFF(3, 4, 3),
+       NCT720X_VOLTAGE_CHANNEL_DIFF(5, 6, 5),
+       NCT720X_VOLTAGE_CHANNEL_DIFF(7, 8, 7),
+       NCT720X_VOLTAGE_CHANNEL_DIFF(9, 10, 9),
+       NCT720X_VOLTAGE_CHANNEL_DIFF(11, 12, 11),
+};
+
+/* Read 1-byte register. Returns unsigned byte data or -ERRNO on error. */
+static int nct720x_read_reg(struct nct720x_chip_info *chip, u8 reg)
+{
+       struct i2c_client *client = chip->client;
+
+       return i2c_smbus_read_byte_data(client, reg);
+}
+
+/* Read 1-byte register. Returns unsigned word data or -ERRNO on error. */
+static int nct720x_read_word_swapped_reg(struct nct720x_chip_info *chip, u8 reg)
+{
+       struct i2c_client *client = chip->client;
+
+       return i2c_smbus_read_word_swapped(client, reg);
+}
+
+/*
+ * Read 2-byte register. Returns register in big-endian format or
+ * -ERRNO on error.
+ */
+static int nct720x_read_reg16(struct nct720x_chip_info *chip, u8 reg)
+{
+       struct i2c_client *client = chip->client;
+       int ret, low;
+
+       mutex_lock(&chip->access_lock);
+       ret = i2c_smbus_read_byte_data(client, reg);
+       if (ret >= 0) {
+               low = ret;
+               ret = i2c_smbus_read_byte_data(client, reg + 1);
+               if (ret >= 0)
+                       ret = low | (ret << 8);
+       }
+
+       mutex_unlock(&chip->access_lock);
+       return ret;
+}
+
+/* Write 1-byte register. Returns 0 or -ERRNO on error. */
+static int nct720x_write_reg(struct nct720x_chip_info *chip, u8 reg, u8 val)
+{
+       struct i2c_client *client = chip->client;
+       int err;
+
+       err = i2c_smbus_write_byte_data(client, reg, val);
+       /* wait for write command to be finished */
+       mdelay(10);
+
+       return err;
+}
+
+static int nct720x_read_raw(struct iio_dev *indio_dev,
+                           struct iio_chan_spec const *chan,
+                           int *val, int *val2, long mask)
+{
+       int index = nct720x_chan_to_index[chan->address];
+       int v1, v2, volt, err;
+       struct nct720x_chip_info *chip = iio_priv(indio_dev);
+
+       if (chan->type != IIO_VOLTAGE)
+               return -EOPNOTSUPP;
+
+       switch (mask) {
+       case IIO_CHAN_INFO_PROCESSED:
+               mutex_lock(&chip->access_lock);
+               if (chip->use_read_byte_vin) {
+                       /*
+                        * MNTVIN Low Byte together with MNTVIN High Byte
+                        * forms the 13-bit count value. If MNTVIN High
+                        * Byte readout is read successively, the
+                        * NCT7201/NCT7202 will latch the MNTVIN Low Byte
+                        * for next read.
+                        */
+                       v1 = nct720x_read_reg(chip, REG_VIN[index]);
+                       if (v1 < 0) {
+                               err = v1;
+                               goto abort;
+                       }
+
+                       v2 = nct720x_read_reg(chip, REG_VOLT_LOW_BYTE);
+                       if (v2 < 0) {
+                               err = v2;
+                               goto abort;
+                       }
+                       volt = (v1 << 8) | v2;  /* Convert back to 16-bit value */
+               } else {
+                       /* NCT7201/NCT7202 also supports read word-size data */
+                       volt = nct720x_read_word_swapped_reg(chip, REG_VIN[index]);
+               }
+
+               /* Voltage(V) = 13bitCountValue * 0.0004995 */
+               volt = (volt >> 3) * NCT720X_IN_SCALING;
+               *val = volt / 10000;
+               mutex_unlock(&chip->access_lock);
+               return IIO_VAL_INT;
+       default:
+               return -EINVAL;
+       }
+abort:
+       mutex_unlock(&chip->access_lock);
+       return err;
+}
+
+static int nct720x_read_event_value(struct iio_dev *indio_dev,
+                                   const struct iio_chan_spec *chan,
+                                   enum iio_event_type type,
+                                   enum iio_event_direction dir,
+                                   enum iio_event_info info,
+                                   int *val, int *val2)
+{
+       struct nct720x_chip_info *chip = iio_priv(indio_dev);
+       int v1, v2, err;
+       int volt = 0;
+       int index = nct720x_chan_to_index[chan->address];
+
+       if (chan->type != IIO_VOLTAGE)
+               return -EOPNOTSUPP;
+
+       if (info == IIO_EV_INFO_VALUE) {
+               if (dir == IIO_EV_DIR_FALLING) {
+                       if (chip->use_read_byte_vin) {
+                               /*
+                                * Low limit VIN Low Byte together with Low limit VIN High Byte
+                                  forms the 13-bit count value
+                                */
+                               mutex_lock(&chip->access_lock);
+                               v1 = nct720x_read_reg(chip, REG_VIN_LOW_LIMIT[index]);
+                               if (v1 < 0) {
+                                       err = v1;
+                                       goto abort;
+                               }
+
+                               v2 = nct720x_read_reg(chip, REG_VIN_LOW_LIMIT_LSB[index]);
+                               if (v2 < 0) {
+                                       err = v2;
+                                       goto abort;
+                               }
+                               mutex_unlock(&chip->access_lock);
+                               volt = (v1 << 8) | v2;  /* Convert back to 16-bit value */
+                       } else {
+                               /* NCT7201/NCT7202 also supports read word-size data */
+                               volt = nct720x_read_word_swapped_reg(chip,
+                                       REG_VIN_LOW_LIMIT[index]);
+                       }
+               } else {
+                       if (chip->use_read_byte_vin) {
+                               /*
+                                * High limit VIN Low Byte together with high limit VIN High Byte
+                                * forms the 13-bit count value
+                                */
+                               mutex_lock(&chip->access_lock);
+                               v1 = nct720x_read_reg(chip, REG_VIN_HIGH_LIMIT[index]);
+                               if (v1 < 0) {
+                                       err = v1;
+                                       goto abort;
+                               }
+
+                               v2 = nct720x_read_reg(chip, REG_VIN_HIGH_LIMIT_LSB[index]);
+                               if (v2 < 0) {
+                                       err = v2;
+                                       goto abort;
+                               }
+                               mutex_unlock(&chip->access_lock);
+                               volt = (v1 << 8) | v2;  /* Convert back to 16-bit value */
+                       } else {
+                               /* NCT7201/NCT7202 also supports read word-size data */
+                               volt = nct720x_read_word_swapped_reg(chip,
+                                       REG_VIN_HIGH_LIMIT[index]);
+                       }
+               }
+       }
+       /* Voltage(V) = 13bitCountValue * 0.0004995 */
+       volt = (volt >> 3) * NCT720X_IN_SCALING;
+       *val = volt / 10000;
+
+       return IIO_VAL_INT;
+abort:
+       mutex_unlock(&chip->access_lock);
+       return err;
+}
+
+static int nct720x_write_event_value(struct iio_dev *indio_dev,
+                                    const struct iio_chan_spec *chan,
+                                    enum iio_event_type type,
+                                    enum iio_event_direction dir,
+                                    enum iio_event_info info,
+                                    int val, int val2)
+{
+       struct nct720x_chip_info *chip = iio_priv(indio_dev);
+       int index, err = 0;
+       long v1, v2, volt;
+
+       index = nct720x_chan_to_index[chan->address];
+       volt = (val * 10000) / NCT720X_IN_SCALING;
+       v1 = volt >> 5;
+       v2 = (volt & 0x1f) << 3;
+
+       if (chan->type != IIO_VOLTAGE)
+               return -EOPNOTSUPP;
+
+       if (info == IIO_EV_INFO_VALUE) {
+               if (dir == IIO_EV_DIR_FALLING) {
+                       mutex_lock(&chip->access_lock);
+                       err = nct720x_write_reg(chip, REG_VIN_LOW_LIMIT[index], v1);
+                       if (err < 0) {
+                               pr_err("Failed to write REG_VIN%d_LOW_LIMIT\n", index + 1);
+                               goto abort;
+                       }
+
+                       err = nct720x_write_reg(chip, REG_VIN_LOW_LIMIT_LSB[index], v2);
+                       if (err < 0) {
+                               pr_err("Failed to write REG_VIN%d_LOW_LIMIT_LSB\n", index + 1);
+                               goto abort;
+                       }
+               } else {
+                       mutex_lock(&chip->access_lock);
+                       err = nct720x_write_reg(chip, REG_VIN_HIGH_LIMIT[index], v1);
+                       if (err < 0) {
+                               pr_err("Failed to write REG_VIN%d_HIGH_LIMIT\n", index + 1);
+                               goto abort;
+                       }
+
+                       err = nct720x_write_reg(chip, REG_VIN_HIGH_LIMIT_LSB[index], v2);
+                       if (err < 0) {
+                               pr_err("Failed to write REG_VIN%d_HIGH_LIMIT_LSB\n", index + 1);
+                               goto abort;
+                       }
+               }
+       }
+abort:
+       mutex_unlock(&chip->access_lock);
+       return err;
+}
+
+static int nct720x_read_event_config(struct iio_dev *indio_dev,
+                                    const struct iio_chan_spec *chan,
+                                    enum iio_event_type type,
+                                    enum iio_event_direction dir)
+{
+       struct nct720x_chip_info *chip = iio_priv(indio_dev);
+       int index = nct720x_chan_to_index[chan->address];
+
+       if (chan->type != IIO_VOLTAGE)
+               return -EOPNOTSUPP;
+
+       return !!(chip->vin_mask & BIT(index));
+}
+
+static int nct720x_write_event_config(struct iio_dev *indio_dev,
+                                     const struct iio_chan_spec *chan,
+                                     enum iio_event_type type,
+                                     enum iio_event_direction dir,
+                                     int state)
+{
+       int err = 0;
+       struct nct720x_chip_info *chip = iio_priv(indio_dev);
+       int index = nct720x_chan_to_index[chan->address];
+       unsigned int mask;

drivers/iio/adc/nct720x.c line 403

Quoted 2 lines

drivers/iio/adc/nct720x.c new file +2 -0

+
+       mask = BIT(index);

nitpick:
You can set the mask near to the place where it is used i.e. just after below if statement and one added advantage will be in case below "return -EOPNOTSUPP" gets executed, you don't even have to set mask.

Quoted 58 lines

drivers/iio/adc/nct720x.c new file +58 -0

+
+       if (chan->type != IIO_VOLTAGE)
+               return -EOPNOTSUPP;
+
+       if (!state && (chip->vin_mask & mask))
+               chip->vin_mask &= ~mask;
+       else if (state && !(chip->vin_mask & mask))
+               chip->vin_mask |= mask;
+
+       mutex_lock(&chip->access_lock);
+
+       err = nct720x_write_reg(chip, REG_CHANNEL_ENABLE_1, chip->vin_mask & 0xff);
+       if (err < 0) {
+               pr_err("Failed to write REG_CHANNEL_ENABLE_1\n");
+               goto abort;
+       }
+
+       if (chip->type == nct7202) {
+               err = nct720x_write_reg(chip, REG_CHANNEL_ENABLE_2, chip->vin_mask >> 8);
+               if (err < 0) {
+                       pr_err("Failed to write REG_CHANNEL_ENABLE_2\n");
+                       goto abort;
+               }
+       }
+abort:
+       mutex_unlock(&chip->access_lock);
+       return err;
+}
+
+static int nct720x_detect(struct i2c_client *client,
+                         struct i2c_board_info *info)
+{
+       struct i2c_adapter *adapter = client->adapter;
+
+       if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+                                    I2C_FUNC_SMBUS_WORD_DATA))
+               return -ENODEV;
+
+       /* Determine the chip type. */
+       if (i2c_smbus_read_byte_data(client, REG_VENDOR_ID) != NUVOTON_ID ||
+           i2c_smbus_read_byte_data(client, REG_CHIP_ID) != NCT720X_ID ||
+           i2c_smbus_read_byte_data(client, REG_DEVICE_ID) != NCT720X_DEVICE_ID)
+               return -ENODEV;
+
+       strscpy(info->type, "nct720x", I2C_NAME_SIZE);
+
+       return 0;
+}
+
+static const struct iio_info nct720x_info = {
+       .read_raw = &nct720x_read_raw,
+       .read_event_config = &nct720x_read_event_config,
+       .write_event_config = &nct720x_write_event_config,
+       .read_event_value = &nct720x_read_event_value,
+       .write_event_value = &nct720x_write_event_value,
+};
+
+static const struct i2c_device_id nct720x_id[];

drivers/iio/adc/nct720x.c line 466

Quoted 5 lines

drivers/iio/adc/nct720x.c new file +5 -0

+
+static int nct720x_init_chip(struct nct720x_chip_info *chip)
+{
+       int value = 0;
+       int err = 0;

Nit pick:
You don't need to initialize err and value.

Quoted 63 lines

drivers/iio/adc/nct720x.c new file +63 -0

+
+       /* Initial reset */
+       err = nct720x_write_reg(chip, REG_CONFIGURATION, CONFIGURATION_INIT);
+       if (err) {
+               pr_err("Failed to write REG_CONFIGURATION\n");
+               return err;
+       }
+
+       /* Enable Channel */
+       err = nct720x_write_reg(chip, REG_CHANNEL_ENABLE_1, 0xff);
+       if (err) {
+               pr_err("Failed to write REG_CHANNEL_ENABLE_1\n");
+               return err;
+       }
+
+       if (chip->type == nct7202) {
+               err = nct720x_write_reg(chip, REG_CHANNEL_ENABLE_2, 0xf);
+               if (err) {
+                       pr_err("Failed to write REG_CHANNEL_ENABLE_2\n");
+                       return err;
+               }
+       }
+
+       value = nct720x_read_reg16(chip, REG_CHANNEL_ENABLE_1);
+       if (value < 0)
+               return value;
+       chip->vin_mask = value;
+
+       /* Start monitoring if needed */
+       value = nct720x_read_reg(chip, REG_CONFIGURATION);
+       if (value < 0) {
+               pr_err("Failed to read REG_CONFIGURATION\n");
+               return value;
+       }
+
+       value |= CONFIGURATION_START;
+       err = nct720x_write_reg(chip, REG_CONFIGURATION, value);
+       if (err < 0) {
+               pr_err("Failed to write REG_CONFIGURATION\n");
+               return err;
+       }
+
+       return 0;
+}
+
+static int nct720x_probe(struct i2c_client *client)
+{
+       const struct i2c_device_id *id = i2c_client_get_device_id(client);
+       struct nct720x_chip_info *chip;
+       struct iio_dev *indio_dev;
+       int ret;
+       u32 tmp;
+
+       indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
+       if (!indio_dev)
+               return -ENOMEM;
+       chip = iio_priv(indio_dev);
+
+       if (client->dev.of_node)
+               chip->type = (enum nct720x_chips)device_get_match_data(&client->dev);
+       else
+               chip->type = i2c_match_id(nct720x_id, client)->driver_data;
+

drivers/iio/adc/nct720x.c line 535

Quoted 6 lines

drivers/iio/adc/nct720x.c new file +6 -0

+       chip->vin_max = (chip->type == nct7201) ? NCT7201_VIN_MAX : NCT7202_VIN_MAX;
+
+       ret = of_property_read_u32(client->dev.of_node, "read-vin-data-size", &tmp);
+       if (ret < 0) {
+               pr_err("read-vin-data-size property not found\n");
+               return ret;

nit: dev_err_probe

drivers/iio/adc/nct720x.c line 544

Quoted 9 lines

drivers/iio/adc/nct720x.c new file +9 -0

+       }
+
+       if (tmp == 8) {
+               chip->use_read_byte_vin = true;
+       } else if (tmp == 16) {
+               chip->use_read_byte_vin = false;
+       } else {
+               pr_err("invalid read-vin-data-size (%d)\n", tmp);
+               return -EINVAL;

nit: dev_err_probe

Quoted 14 lines

drivers/iio/adc/nct720x.c new file +14 -0

+       }
+
+       mutex_init(&chip->access_lock);
+
+       /* this is only used for device removal purposes */
+       i2c_set_clientdata(client, indio_dev);
+
+       chip->client = client;
+
+       ret = nct720x_init_chip(chip);
+       if (ret < 0)
+               return ret;
+
+       indio_dev->name = id->name;

drivers/iio/adc/nct720x.c line 564

Quoted 6 lines

drivers/iio/adc/nct720x.c new file +6 -0

+       indio_dev->channels = nct720x_channels;
+       indio_dev->num_channels = ARRAY_SIZE(nct720x_channels);
+       indio_dev->info = &nct720x_info;
+       indio_dev->modes = INDIO_DIRECT_MODE;
+
+       iio_device_register(indio_dev);

devm_iio_device_register?

drivers/iio/adc/nct720x.c line 573

Quoted 9 lines

drivers/iio/adc/nct720x.c new file +9 -0

+
+       return 0;
+}
+
+static void nct720x_remove(struct i2c_client *client)
+{
+       struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+       iio_device_unregister(indio_dev);

wouldn't need if used devm_ version

Quoted 48 lines

drivers/iio/adc/nct720x.c new file +44 -1

+}
+
+static const unsigned short nct720x_address_list[] = {
+       0x1d, 0x1e, 0x35, 0x36, I2C_CLIENT_END
+};
+
+static const struct i2c_device_id nct720x_id[] = {
+       { "nct7201", nct7201 },
+       { "nct7202", nct7202 },
+       {}
+};
+MODULE_DEVICE_TABLE(i2c, nct720x_id);
+
+static const struct of_device_id nct720x_of_match[] = {
+       {
+               .compatible = "nuvoton,nct7201",
+               .data = (void *)nct7201
+       },
+       {
+               .compatible = "nuvoton,nct7202",
+               .data = (void *)nct7202
+       },
+       { },
+};
+
+MODULE_DEVICE_TABLE(of, nct720x_of_match);
+
+static struct i2c_driver nct720x_driver = {
+       .driver = {
+               .name   = "nct720x",
+               .of_match_table = nct720x_of_match,
+       },
+       .probe = nct720x_probe,
+       .remove = nct720x_remove,
+       .id_table = nct720x_id,
+       .detect = nct720x_detect,
+       .address_list = nct720x_address_list,
+};
+
+module_i2c_driver(nct720x_driver);
+
+MODULE_AUTHOR("Eason Yang <[email protected]>");
+MODULE_DESCRIPTION("Nuvoton NCT720x voltage monitor driver");
+MODULE_LICENSE("GPL");
--

2.34.1

Add Nuvoton NCT7201/NCT7202 system voltage monitor 12-bit ADC driver

NCT7201/NCT7202 supports up to 12 analog voltage monitor inputs and up to 4 SMBus addresses by ADDR pin. Meanwhile, ALERT# hardware event pins for independent alarm signals, and the all threshold values could be set for system protection without any timing delay. It also supports reset input RSTIN# to recover system from a fault condition.

Currently, only single-edge mode conversion and threshold events support.

+ * Copyright (c) 2022 Nuvoton Inc.

+#include <linux/init.h>

+};

drivers/iio/adc/nct720x.c new file +16 -0

+/* Read 1-byte register. Returns unsigned byte data or -ERRNO on error. */
+static int nct720x_read_reg(struct nct720x_chip_info *chip, u8 reg)
+{
+	struct i2c_client *client = chip->client;
+
+	return i2c_smbus_read_byte_data(client, reg);
+}
+
+/* Read 1-byte register. Returns unsigned word data or -ERRNO on error. */
+static int nct720x_read_word_swapped_reg(struct nct720x_chip_info *chip, u8 reg)
+{
+	struct i2c_client *client = chip->client;
+
+	return i2c_smbus_read_word_swapped(client, reg);
+}
+

drivers/iio/adc/nct720x.c new file +4 -0

+	mdelay(10);
+
+	return err;
+}

drivers/iio/adc/nct720x.c new file +24 -0

+static int nct720x_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long mask)
+{
+	int index = nct720x_chan_to_index[chan->address];
+	int v1, v2, volt, err;
+	struct nct720x_chip_info *chip = iio_priv(indio_dev);
+
+	if (chan->type != IIO_VOLTAGE)
+		return -EOPNOTSUPP;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_PROCESSED:
+		mutex_lock(&chip->access_lock);
+		if (chip->use_read_byte_vin) {
+			/*
+			 * MNTVIN Low Byte together with MNTVIN High Byte
+			 * forms the 13-bit count value. If MNTVIN High
+			 * Byte readout is read successively, the
+			 * NCT7201/NCT7202 will latch the MNTVIN Low Byte
+			 * for next read.
+			 */
+			v1 = nct720x_read_reg(chip, REG_VIN[index]);
+			if (v1 < 0) {

drivers/iio/adc/nct720x.c new file +6 -0

+		} else {
+			/* NCT7201/NCT7202 also supports read word-size data */
+			volt = nct720x_read_word_swapped_reg(chip, REG_VIN[index]);
+		}
+
+		/* Voltage(V) = 13bitCountValue * 0.0004995 */

+}

drivers/iio/adc/nct720x.c new file +36 -0

+	if (chan->type != IIO_VOLTAGE)
+		return -EOPNOTSUPP;
+
+	if (info == IIO_EV_INFO_VALUE) {
+		if (dir == IIO_EV_DIR_FALLING) {
+			mutex_lock(&chip->access_lock);
+			err = nct720x_write_reg(chip, REG_VIN_LOW_LIMIT[index], v1);
+			if (err < 0) {
+				pr_err("Failed to write REG_VIN%d_LOW_LIMIT\n", index + 1);
+				goto abort;
+			}
+
+			err = nct720x_write_reg(chip, REG_VIN_LOW_LIMIT_LSB[index], v2);
+			if (err < 0) {
+				pr_err("Failed to write REG_VIN%d_LOW_LIMIT_LSB\n", index + 1);
+				goto abort;
+			}
+		} else {
+			mutex_lock(&chip->access_lock);
+			err = nct720x_write_reg(chip, REG_VIN_HIGH_LIMIT[index], v1);
+			if (err < 0) {
+				pr_err("Failed to write REG_VIN%d_HIGH_LIMIT\n", index + 1);
+				goto abort;
+			}
+
+			err = nct720x_write_reg(chip, REG_VIN_HIGH_LIMIT_LSB[index], v2);
+			if (err < 0) {
+				pr_err("Failed to write REG_VIN%d_HIGH_LIMIT_LSB\n", index + 1);
+				goto abort;
+			}
+		}
+	}
+abort:
+	mutex_unlock(&chip->access_lock);
+	return err;
+}

+static const struct i2c_device_id nct720x_id[];

drivers/iio/adc/nct720x.c new file +27 -0

+		if (err) {
+			pr_err("Failed to write REG_CHANNEL_ENABLE_2\n");
+			return err;
+		}
+	}
+
+	value = nct720x_read_reg16(chip, REG_CHANNEL_ENABLE_1);
+	if (value < 0)
+		return value;
+	chip->vin_mask = value;
+
+	/* Start monitoring if needed */
+	value = nct720x_read_reg(chip, REG_CONFIGURATION);
+	if (value < 0) {
+		pr_err("Failed to read REG_CONFIGURATION\n");
+		return value;
+	}
+
+	value |= CONFIGURATION_START;
+	err = nct720x_write_reg(chip, REG_CONFIGURATION, value);
+	if (err < 0) {
+		pr_err("Failed to write REG_CONFIGURATION\n");
+		return err;
+	}
+
+	return 0;
+}

drivers/iio/adc/nct720x.c new file +4 -0

+	if (ret < 0) {
+		pr_err("read-vin-data-size property not found\n");
+		return ret;
+	}