[PATCH v7 0/4] Add devicetree support for max6639

[PATCH v7 0/4] Add devicetree support for max6639

[Naresh Solanki]

These patches adds devicetree support for MAX6639.

Changes in V7:
- Split the patch into
 1. add dt support for max6639
 2. Add pwm support
- Ad DT property min-rpm in fan-common.yaml
Changes in V6:
- Remove unused header file
- minor cleanup 
Changes in V5:
- Add pwms support
Changes V4:
- Fix dt error
- update comment
Changes V3:
- correct fan dt property name
- remove unrelevent changes
Changes V2:
- Fix dt schema error.
Changes:
- Add fan-common dt schema.
- add dt-binding support for max6639
- add max6639 specific property

Marcello Sylvester Bauer (1):
  dt-bindings: hwmon: Add binding for max6639

Naresh Solanki (3):
  dt-bindings: hwmon: fan: Add fan binding to schema
  hwmon: (max6639) Change from pdata to dt configuration
  hwmon: (max6639) Add pwm support

 .../devicetree/bindings/hwmon/fan-common.yaml |  47 ++
 .../bindings/hwmon/maxim,max6639.yaml         |  93 ++++
 drivers/hwmon/Kconfig                         |   1 +
 drivers/hwmon/max6639.c                       | 460 +++++++++++++++---
 include/linux/platform_data/max6639.h         |  15 -
 5 files changed, 527 insertions(+), 89 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml
 create mode 100644 Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
 delete mode 100644 include/linux/platform_data/max6639.h


base-commit: 27fea302952d8c90cafbdbee96bafeca03544401
-- 
2.37.3

[PATCH v7 1/4] dt-bindings: hwmon: fan: Add fan binding to schema

[Naresh Solanki]

Add common fan properties bindings to a schema.

Bindings for fan controllers can reference the common schema for the
fan

child nodes:

  patternProperties:
    "^fan@[0-2]":
      type: object
      $ref: fan-common.yaml#

Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
---
 .../devicetree/bindings/hwmon/fan-common.yaml | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml

diff --git a/Documentation/devicetree/bindings/hwmon/fan-common.yaml b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
new file mode 100644
index 000000000000..0535d37624cc
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/fan-common.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common fan properties
+
+maintainers:
+  - Naresh Solanki <naresh.solanki@9elements.com>
+
+properties:
+  max-rpm:
+    description:
+      Max RPM supported by fan.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  min-rpm:
+    description:
+      Min RPM supported by fan.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  pulses-per-revolution:
+    description:
+      The number of pulse from fan sensor per revolution.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  target-rpm:
+    description:
+      Target RPM the fan should be configured during driver probe.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  pwms:
+    description:
+      PWM provider.
+
+  label:
+    description:
+      Optional fan label
+
+  fan-supply:
+    description:
+      Power supply for fan.
+
+additionalProperties: true
+
+...
-- 
2.37.3

Re: [PATCH v7 1/4] dt-bindings: hwmon: fan: Add fan binding to schema

[Guenter Roeck]

On 11/21/22 04:29, Naresh Solanki wrote:
> Add common fan properties bindings to a schema.
> 
> Bindings for fan controllers can reference the common schema for the
> fan
> 
> child nodes:
> 
>    patternProperties:
>      "^fan@[0-2]":
>        type: object
>        $ref: fan-common.yaml#
> 
> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> ---
>   .../devicetree/bindings/hwmon/fan-common.yaml | 47 +++++++++++++++++++
>   1 file changed, 47 insertions(+)
>   create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/fan-common.yaml b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> new file mode 100644
> index 000000000000..0535d37624cc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> @@ -0,0 +1,47 @@
> +# SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/fan-common.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Common fan properties
> +
> +maintainers:
> +  - Naresh Solanki <naresh.solanki@9elements.com>
> +
> +properties:
> +  max-rpm:
> +    description:
> +      Max RPM supported by fan.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  min-rpm:
> +    description:
> +      Min RPM supported by fan.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  pulses-per-revolution:
> +    description:
> +      The number of pulse from fan sensor per revolution.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  target-rpm:
> +    description:
> +      Target RPM the fan should be configured during driver probe.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  pwms:
> +    description:
> +      PWM provider.
> +
> +  label:
> +    description:
> +      Optional fan label
> +
> +  fan-supply:
> +    description:
> +      Power supply for fan.
> +
> +additionalProperties: true
> +
> +...

Still, from my second reply to v6:

 > Another property which is definitely missing and needed
 > will be DC vs. PWM control. That is currently pwm[1-*]_mode
 > in sysfs attributes, but it is really a fan attribute.
 >
 > Many fans are DC controlled, so this property is absolutely
 > necessary.

Plus, with DC control there is no pwm. It would be absolutely wrong
to declare that a fan controller MUST be pwm based.

Ultimately, there are three types of fan controllers:

- PWM control, such as MAX6639
- DC control, such as MAX6620 or MAX6650/6651
- Configurable, such as MAX1669 or pretty much all fan controllers
   included in SuperIO chips

Generic fan control bindings simply _have_ to take this into account.

Guenter

Re: [PATCH v7 1/4] dt-bindings: hwmon: fan: Add fan binding to schema

[Krzysztof Kozlowski]

On 21/11/2022 13:29, Naresh Solanki wrote:
> Add common fan properties bindings to a schema.
> 
> Bindings for fan controllers can reference the common schema for the
> fan
> 
> child nodes:
> 
>   patternProperties:
>     "^fan@[0-2]":
>       type: object
>       $ref: fan-common.yaml#
> 
> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> ---
>  .../devicetree/bindings/hwmon/fan-common.yaml | 47 +++++++++++++++++++
>  1 file changed, 47 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/fan-common.yaml b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> new file mode 100644
> index 000000000000..0535d37624cc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> @@ -0,0 +1,47 @@
> +# SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/fan-common.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Common fan properties

I responded to v6, so let me paste here as well:
Common Fan Properties

> +
> +maintainers:
> +  - Naresh Solanki <naresh.solanki@9elements.com>
> +
> +properties:
> +  max-rpm:
> +    description:
> +      Max RPM supported by fan.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  min-rpm:
> +    description:
> +      Min RPM supported by fan.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  pulses-per-revolution:
> +    description:
> +      The number of pulse from fan sensor per revolution.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  target-rpm:
> +    description:
> +      Target RPM the fan should be configured during driver probe.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  pwms:
> +    description:
> +      PWM provider.

Maybe:
type: object

> +


Best regards,
Krzysztof

Re: [PATCH v7 1/4] dt-bindings: hwmon: fan: Add fan binding to schema

[Krzysztof Kozlowski]

On 21/11/2022 13:29, Naresh Solanki wrote:

> +  pulses-per-revolution:
> +    description:
> +      The number of pulse from fan sensor per revolution.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  target-rpm:
> +    description:
> +      Target RPM the fan should be configured during driver probe.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  pwms:
> +    description:
> +      PWM provider.

Ah, so it is not a PWM provider by this FAN controller? A bit confusing
description. Instead maybe:
	PWM signal for the fan

and do you expect more than one PWM for one fan?

Best regards,
Krzysztof

Re: [PATCH v7 1/4] dt-bindings: hwmon: fan: Add fan binding to schema

[Naresh Solanki]

Hi Krzysztof,

On 29-11-2022 01:42 pm, Krzysztof Kozlowski wrote:
> On 21/11/2022 13:29, Naresh Solanki wrote:
> 
>> +  pulses-per-revolution:
>> +    description:
>> +      The number of pulse from fan sensor per revolution.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +
>> +  target-rpm:
>> +    description:
>> +      Target RPM the fan should be configured during driver probe.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +
>> +  pwms:
>> +    description:
>> +      PWM provider.
> 
> Ah, so it is not a PWM provider by this FAN controller? A bit confusing
> description. Instead maybe:
> 	PWM signal for the fan
Sure.
> 
> and do you expect more than one PWM for one fan?
One pwm per fan
> 
> Best regards,
> Krzysztof
> 

Regards,
Naresh

Re: [PATCH v7 1/4] dt-bindings: hwmon: fan: Add fan binding to schema

[Krzysztof Kozlowski]

On 29/11/2022 16:46, Naresh Solanki wrote:
> Hi Krzysztof,
> 
> On 29-11-2022 01:42 pm, Krzysztof Kozlowski wrote:
>> On 21/11/2022 13:29, Naresh Solanki wrote:
>>
>>> +  pulses-per-revolution:
>>> +    description:
>>> +      The number of pulse from fan sensor per revolution.
>>> +    $ref: /schemas/types.yaml#/definitions/uint32
>>> +
>>> +  target-rpm:
>>> +    description:
>>> +      Target RPM the fan should be configured during driver probe.
>>> +    $ref: /schemas/types.yaml#/definitions/uint32
>>> +
>>> +  pwms:
>>> +    description:
>>> +      PWM provider.
>>
>> Ah, so it is not a PWM provider by this FAN controller? A bit confusing
>> description. Instead maybe:
>> 	PWM signal for the fan
> Sure.
>>
>> and do you expect more than one PWM for one fan?
> One pwm per fan

then:
  maxItems: 1

Best regards,
Krzysztof

Re: [PATCH v7 1/4] dt-bindings: hwmon: fan: Add fan binding to schema

[Naresh Solanki]

On 29-11-2022 09:27 pm, Krzysztof Kozlowski wrote:
> On 29/11/2022 16:46, Naresh Solanki wrote:
>> Hi Krzysztof,
>>
>> On 29-11-2022 01:42 pm, Krzysztof Kozlowski wrote:
>>> On 21/11/2022 13:29, Naresh Solanki wrote:
>>>
>>>> +  pulses-per-revolution:
>>>> +    description:
>>>> +      The number of pulse from fan sensor per revolution.
>>>> +    $ref: /schemas/types.yaml#/definitions/uint32
>>>> +
>>>> +  target-rpm:
>>>> +    description:
>>>> +      Target RPM the fan should be configured during driver probe.
>>>> +    $ref: /schemas/types.yaml#/definitions/uint32
>>>> +
>>>> +  pwms:
>>>> +    description:
>>>> +      PWM provider.
>>>
>>> Ah, so it is not a PWM provider by this FAN controller? A bit confusing
>>> description. Instead maybe:
>>> 	PWM signal for the fan
>> Sure.
>>>
>>> and do you expect more than one PWM for one fan?
>> One pwm per fan
> 
> then:
>    maxItems: 1
> 
Sure
> Best regards,
> Krzysztof
> 
Regards,
Naresh

[PATCH v7 2/4] dt-bindings: hwmon: Add binding for max6639

[Naresh Solanki]

From: Marcello Sylvester Bauer <sylv@sylv.io>

Add Devicetree binding documentation for Maxim MAX6639 temperature
monitor with PWM fan-speed controller.

Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
---
 .../bindings/hwmon/maxim,max6639.yaml         | 93 +++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml

diff --git a/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml b/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
new file mode 100644
index 000000000000..da040b11d2ab
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
@@ -0,0 +1,93 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+
+$id: http://devicetree.org/schemas/hwmon/maxim,max6639.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Maxim max6639
+
+maintainers:
+  - Roland Stigge <stigge@antcom.de>
+
+description: |
+  The MAX6639 is a 2-channel temperature monitor with dual, automatic, PWM
+  fan-speed controller.  It monitors its own temperature and one external
+  diode-connected transistor or the temperatures of two external diode-connected
+  transistors, typically available in CPUs, FPGAs, or GPUs.
+
+  Datasheets:
+    https://datasheets.maximintegrated.com/en/ds/MAX6639-MAX6639F.pdf
+
+properties:
+  compatible:
+    enum:
+      - maxim,max6639
+
+  reg:
+    maxItems: 1
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+  '#pwm-cells':
+    const: 3
+
+required:
+  - compatible
+  - reg
+
+patternProperties:
+  "^fan@[0-1]$":
+    type: object
+    description: |
+      Represents the two fans and their specific configuration.
+
+    $ref: fan-common.yaml#
+
+    properties:
+      reg:
+        description: |
+          The fan number.
+        items:
+          minimum: 0
+          maximum: 1
+
+    required:
+      - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        fan1: fan-controller@10 {
+            compatible = "maxim,max6639";
+            reg = <0x10>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+            #pwm-cells = <3>;
+
+            fan@0 {
+                reg = <0x0>;
+                pulses-per-revolution = <2>;
+                max-rpm = <4000>;
+                target-rpm = <1000>;
+                pwms = <&fan1 0 25000 0>;
+            };
+
+            fan@1 {
+                reg = <0x1>;
+                pulses-per-revolution = <2>;
+                max-rpm = <8000>;
+                pwms = <&fan1 1 25000 0>;
+            };
+            };
+    };
+...
-- 
2.37.3

Re: [PATCH v7 2/4] dt-bindings: hwmon: Add binding for max6639

[Krzysztof Kozlowski]

On 21/11/2022 13:29, Naresh Solanki wrote:
> From: Marcello Sylvester Bauer <sylv@sylv.io>
> 
> Add Devicetree binding documentation for Maxim MAX6639 temperature
> monitor with PWM fan-speed controller.
> 
> Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> ---
>  .../bindings/hwmon/maxim,max6639.yaml         | 93 +++++++++++++++++++
>  1 file changed, 93 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml b/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
> new file mode 100644
> index 000000000000..da040b11d2ab
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
> @@ -0,0 +1,93 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +
> +$id: http://devicetree.org/schemas/hwmon/maxim,max6639.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Maxim max6639
> +
> +maintainers:
> +  - Roland Stigge <stigge@antcom.de>
> +
> +description: |
> +  The MAX6639 is a 2-channel temperature monitor with dual, automatic, PWM
> +  fan-speed controller.  It monitors its own temperature and one external
> +  diode-connected transistor or the temperatures of two external diode-connected
> +  transistors, typically available in CPUs, FPGAs, or GPUs.
> +
> +  Datasheets:
> +    https://datasheets.maximintegrated.com/en/ds/MAX6639-MAX6639F.pdf
> +
> +properties:
> +  compatible:
> +    enum:
> +      - maxim,max6639
> +
> +  reg:
> +    maxItems: 1
> +
> +  '#address-cells':
> +    const: 1
> +
> +  '#size-cells':
> +    const: 0
> +
> +  '#pwm-cells':
> +    const: 3
> +
> +required:
> +  - compatible
> +  - reg
> +
> +patternProperties:
> +  "^fan@[0-1]$":
> +    type: object
> +    description: |
> +      Represents the two fans and their specific configuration.
> +
> +    $ref: fan-common.yaml#

unevalauatedProperties: false

> +
> +    properties:
> +      reg:
> +        description: |
> +          The fan number.
> +        items:
> +          minimum: 0
> +          maximum: 1

This is a bit unusual syntax. Drop "items", I think it should be more
obvious.

> +
> +    required:
> +      - reg
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        fan1: fan-controller@10 {
> +            compatible = "maxim,max6639";
> +            reg = <0x10>;
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +            #pwm-cells = <3>;
> +
> +            fan@0 {
> +                reg = <0x0>;
> +                pulses-per-revolution = <2>;
> +                max-rpm = <4000>;
> +                target-rpm = <1000>;
> +                pwms = <&fan1 0 25000 0>;
> +            };
> +
> +            fan@1 {
> +                reg = <0x1>;
> +                pulses-per-revolution = <2>;
> +                max-rpm = <8000>;
> +                pwms = <&fan1 1 25000 0>;
> +            };
> +            };

Fix indentation.

> +    };
> +...

Best regards,
Krzysztof

Re: [PATCH v7 2/4] dt-bindings: hwmon: Add binding for max6639

[Naresh Solanki]

Hi Krzysztof,

On 29-11-2022 01:44 pm, Krzysztof Kozlowski wrote:
> On 21/11/2022 13:29, Naresh Solanki wrote:
>> From: Marcello Sylvester Bauer <sylv@sylv.io>
>>
>> Add Devicetree binding documentation for Maxim MAX6639 temperature
>> monitor with PWM fan-speed controller.
>>
>> Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
>> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
>> ---
>>   .../bindings/hwmon/maxim,max6639.yaml         | 93 +++++++++++++++++++
>>   1 file changed, 93 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml b/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
>> new file mode 100644
>> index 000000000000..da040b11d2ab
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
>> @@ -0,0 +1,93 @@
>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +
>> +$id: http://devicetree.org/schemas/hwmon/maxim,max6639.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Maxim max6639
>> +
>> +maintainers:
>> +  - Roland Stigge <stigge@antcom.de>
>> +
>> +description: |
>> +  The MAX6639 is a 2-channel temperature monitor with dual, automatic, PWM
>> +  fan-speed controller.  It monitors its own temperature and one external
>> +  diode-connected transistor or the temperatures of two external diode-connected
>> +  transistors, typically available in CPUs, FPGAs, or GPUs.
>> +
>> +  Datasheets:
>> +    https://datasheets.maximintegrated.com/en/ds/MAX6639-MAX6639F.pdf
>> +
>> +properties:
>> +  compatible:
>> +    enum:
>> +      - maxim,max6639
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  '#address-cells':
>> +    const: 1
>> +
>> +  '#size-cells':
>> +    const: 0
>> +
>> +  '#pwm-cells':
>> +    const: 3
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +
>> +patternProperties:
>> +  "^fan@[0-1]$":
>> +    type: object
>> +    description: |
>> +      Represents the two fans and their specific configuration.
>> +
>> +    $ref: fan-common.yaml#
> 
> unevalauatedProperties: false
> 
Sure
>> +
>> +    properties:
>> +      reg:
>> +        description: |
>> +          The fan number.
>> +        items:
>> +          minimum: 0
>> +          maximum: 1
> 
> This is a bit unusual syntax. Drop "items", I think it should be more
> obvious.
> 
Sure
>> +
>> +    required:
>> +      - reg
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    i2c {
>> +        #address-cells = <1>;
>> +        #size-cells = <0>;
>> +
>> +        fan1: fan-controller@10 {
>> +            compatible = "maxim,max6639";
>> +            reg = <0x10>;
>> +            #address-cells = <1>;
>> +            #size-cells = <0>;
>> +            #pwm-cells = <3>;
>> +
>> +            fan@0 {
>> +                reg = <0x0>;
>> +                pulses-per-revolution = <2>;
>> +                max-rpm = <4000>;
>> +                target-rpm = <1000>;
>> +                pwms = <&fan1 0 25000 0>;
>> +            };
>> +
>> +            fan@1 {
>> +                reg = <0x1>;
>> +                pulses-per-revolution = <2>;
>> +                max-rpm = <8000>;
>> +                pwms = <&fan1 1 25000 0>;
>> +            };
>> +            };
> 
> Fix indentation.
>
Sure

>> +    };
>> +...
> 
> Best regards,
> Krzysztof
> 
Regards,
Naresh

[PATCH v7 3/4] hwmon: (max6639) Change from pdata to dt configuration

[Naresh Solanki]

max6639_platform_data is not used by any in-kernel driver and does not
address the MAX6639 fans separately.
Move to device tree configuration with explicit properties to configure
each fan.

Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
---
 drivers/hwmon/max6639.c               | 246 +++++++++++++++++++-------
 include/linux/platform_data/max6639.h |  15 --
 2 files changed, 178 insertions(+), 83 deletions(-)
 delete mode 100644 include/linux/platform_data/max6639.h

diff --git a/drivers/hwmon/max6639.c b/drivers/hwmon/max6639.c
index 9b895402c80d..feafa3511297 100644
--- a/drivers/hwmon/max6639.c
+++ b/drivers/hwmon/max6639.c
@@ -19,7 +19,6 @@
 #include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
-#include <linux/platform_data/max6639.h>
 
 /* Addresses to scan */
 static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
@@ -54,9 +53,12 @@ static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
 #define MAX6639_GCONFIG_PWM_FREQ_HI		0x08
 
 #define MAX6639_FAN_CONFIG1_PWM			0x80
-
+#define MAX6639_REG_FAN_CONFIG2a_PWM_POL	0x02
 #define MAX6639_FAN_CONFIG3_THERM_FULL_SPEED	0x40
+#define MAX6639_FAN_CONFIG3_FREQ_MASK		0x03
+#define MAX6639_REG_TARGTDUTY_SLOT		120
 
+/* Tach supported range. This internally controls tach frequency */
 static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };
 
 #define FAN_FROM_REG(val, rpm_range)	((val) == 0 || (val) == 255 ? \
@@ -76,18 +78,21 @@ struct max6639_data {
 	u16 temp[2];		/* Temperature, in 1/8 C, 0..255 C */
 	bool temp_fault[2];	/* Detected temperature diode failure */
 	u8 fan[2];		/* Register value: TACH count for fans >=30 */
+	u32 target_rpm[2];
+	u32 max_rpm[2];
+	u8 pwm[2];
+
 	u8 status;		/* Detected channel alarms and fan failures */
 
 	/* Register values only written to */
-	u8 pwm[2];		/* Register value: Duty cycle 0..120 */
 	u8 temp_therm[2];	/* THERM Temperature, 0..255 C (->_max) */
 	u8 temp_alert[2];	/* ALERT Temperature, 0..255 C (->_crit) */
 	u8 temp_ot[2];		/* OT Temperature, 0..255 C (->_emergency) */
 
 	/* Register values initialized only once */
-	u8 ppr;			/* Pulses per rotation 0..3 for 1..4 ppr */
-	u8 rpm_range;		/* Index in above rpm_ranges table */
-
+	u8 ppr[2];		/* Pulses per rotation 0..3 for 1..4 ppr */
+	u8 rpm_range[2];	/* Index in above rpm_ranges table */
+	u8 pwm_polarity[2];
 	/* Optional regulator for FAN supply */
 	struct regulator *reg;
 };
@@ -282,6 +287,7 @@ static ssize_t pwm_show(struct device *dev, struct device_attribute *dev_attr,
 	struct max6639_data *data = dev_get_drvdata(dev);
 
 	return sprintf(buf, "%d\n", data->pwm[attr->index] * 255 / 120);
+
 }
 
 static ssize_t pwm_store(struct device *dev,
@@ -302,10 +308,10 @@ static ssize_t pwm_store(struct device *dev,
 
 	mutex_lock(&data->update_lock);
 	data->pwm[attr->index] = (u8)(val * 120 / 255);
-	i2c_smbus_write_byte_data(client,
-				  MAX6639_REG_TARGTDUTY(attr->index),
-				  data->pwm[attr->index]);
+	i2c_smbus_write_byte_data(client, MAX6639_REG_TARGTDUTY(attr->index),
+				 data->pwm[attr->index]);
 	mutex_unlock(&data->update_lock);
+
 	return count;
 }
 
@@ -319,7 +325,7 @@ static ssize_t fan_input_show(struct device *dev,
 		return PTR_ERR(data);
 
 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[attr->index],
-		       data->rpm_range));
+		       data->rpm_range[attr->index]));
 }
 
 static ssize_t alarm_show(struct device *dev,
@@ -386,29 +392,40 @@ static struct attribute *max6639_attrs[] = {
 ATTRIBUTE_GROUPS(max6639);
 
 /*
- *  returns respective index in rpm_ranges table
- *  1 by default on invalid range
+ *  Get respective index in rpm_ranges table
  */
-static int rpm_range_to_reg(int range)
+static int rpm_range_to_index(struct device *dev, u8 *index, int rpm)
 {
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(rpm_ranges); i++) {
-		if (rpm_ranges[i] == range)
-			return i;
+	if (rpm < 0)
+		return -EINVAL;
+
+	/* Set index based on chip support */
+	switch (rpm) {
+	case 0 ... 2000:
+		*index = 0;
+		break;
+	case 2001 ... 4000:
+		*index = 1;
+		break;
+	case 4001 ... 8000:
+		*index = 2;
+		break;
+	case 8001 ... 16000:
+		*index = 3;
+		break;
+	default:
+		/* Use max range for higher RPM */
+		dev_warn(dev,
+		    "RPM higher than supported range. Default to 16000 RPM");
+		*index = 3;
 	}
-
-	return 1; /* default: 4000 RPM */
+	return 0;
 }
 
 static int max6639_init_client(struct i2c_client *client,
 			       struct max6639_data *data)
 {
-	struct max6639_platform_data *max6639_info =
-		dev_get_platdata(&client->dev);
-	int i;
-	int rpm_range = 1; /* default: 4000 RPM */
-	int err;
+	int i, err;
 
 	/* Reset chip to default values, see below for GCONFIG setup */
 	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
@@ -416,51 +433,29 @@ static int max6639_init_client(struct i2c_client *client,
 	if (err)
 		goto exit;
 
-	/* Fans pulse per revolution is 2 by default */
-	if (max6639_info && max6639_info->ppr > 0 &&
-			max6639_info->ppr < 5)
-		data->ppr = max6639_info->ppr;
-	else
-		data->ppr = 2;
-	data->ppr -= 1;
-
-	if (max6639_info)
-		rpm_range = rpm_range_to_reg(max6639_info->rpm_range);
-	data->rpm_range = rpm_range;
-
 	for (i = 0; i < 2; i++) {
 
 		/* Set Fan pulse per revolution */
-		err = i2c_smbus_write_byte_data(client,
-				MAX6639_REG_FAN_PPR(i),
-				data->ppr << 6);
+		err = i2c_smbus_write_byte_data(client,	MAX6639_REG_FAN_PPR(i),
+						data->ppr[i] << 6);
 		if (err)
 			goto exit;
 
 		/* Fans config PWM, RPM */
 		err = i2c_smbus_write_byte_data(client,
-			MAX6639_REG_FAN_CONFIG1(i),
-			MAX6639_FAN_CONFIG1_PWM | rpm_range);
-		if (err)
-			goto exit;
-
-		/* Fans PWM polarity high by default */
-		if (max6639_info && max6639_info->pwm_polarity == 0)
-			err = i2c_smbus_write_byte_data(client,
-				MAX6639_REG_FAN_CONFIG2a(i), 0x00);
-		else
-			err = i2c_smbus_write_byte_data(client,
-				MAX6639_REG_FAN_CONFIG2a(i), 0x02);
+						MAX6639_REG_FAN_CONFIG1(i),
+						MAX6639_FAN_CONFIG1_PWM |
+						data->rpm_range[i]);
 		if (err)
 			goto exit;
 
 		/*
-		 * /THERM full speed enable,
+		 * /THERM full speed disable,
 		 * PWM frequency 25kHz, see also GCONFIG below
 		 */
 		err = i2c_smbus_write_byte_data(client,
-			MAX6639_REG_FAN_CONFIG3(i),
-			MAX6639_FAN_CONFIG3_THERM_FULL_SPEED | 0x03);
+						MAX6639_REG_FAN_CONFIG3(i),
+						0x03);
 		if (err)
 			goto exit;
 
@@ -469,31 +464,34 @@ static int max6639_init_client(struct i2c_client *client,
 		data->temp_alert[i] = 90;
 		data->temp_ot[i] = 100;
 		err = i2c_smbus_write_byte_data(client,
-				MAX6639_REG_THERM_LIMIT(i),
-				data->temp_therm[i]);
+						MAX6639_REG_THERM_LIMIT(i),
+						data->temp_therm[i]);
 		if (err)
 			goto exit;
 		err = i2c_smbus_write_byte_data(client,
-				MAX6639_REG_ALERT_LIMIT(i),
-				data->temp_alert[i]);
+						MAX6639_REG_ALERT_LIMIT(i),
+						data->temp_alert[i]);
 		if (err)
 			goto exit;
 		err = i2c_smbus_write_byte_data(client,
-				MAX6639_REG_OT_LIMIT(i), data->temp_ot[i]);
+						MAX6639_REG_OT_LIMIT(i),
+						data->temp_ot[i]);
 		if (err)
 			goto exit;
 
 		/* PWM 120/120 (i.e. 100%) */
-		data->pwm[i] = 120;
-		err = i2c_smbus_write_byte_data(client,
-				MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
+		data->pwm[i] = data->target_rpm[i];
+		err = i2c_smbus_write_byte_data(client, MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
+
 		if (err)
 			goto exit;
+
 	}
 	/* Start monitoring */
 	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
 		MAX6639_GCONFIG_DISABLE_TIMEOUT | MAX6639_GCONFIG_CH2_LOCAL |
 		MAX6639_GCONFIG_PWM_FREQ_HI);
+
 exit:
 	return err;
 }
@@ -524,12 +522,95 @@ static void max6639_regulator_disable(void *data)
 	regulator_disable(data);
 }
 
+static int max6639_probe_child_from_dt(struct i2c_client *client,
+				      struct device_node *child,
+				      struct max6639_data *data)
+
+{
+	struct device *dev = &client->dev;
+	u32 i, maxrpm;
+	int val, err;
+
+	err = of_property_read_u32(child, "reg", &i);
+	if (err) {
+		dev_err(dev, "missing reg property of %pOFn\n", child);
+		return err;
+	}
+
+	if (i >= 2) {
+		dev_err(dev, "invalid reg %d of %pOFn\n", i, child);
+		return -EINVAL;
+	}
+
+	err = of_property_read_u32(child, "pulses-per-revolution", &val);
+	if (err) {
+		dev_err(dev, "missing pulses-per-revolution property of %pOFn",
+			child);
+		return err;
+	}
+
+	if (val < 0 || val > 5) {
+		dev_err(dev, "invalid pulses-per-revolution %d of %pOFn\n", val,
+			child);
+		return -EINVAL;
+	}
+	data->ppr[i] = val;
+
+	err = of_property_read_u32(child, "max-rpm", &maxrpm);
+	if (err) {
+		dev_err(dev, "missing max-rpm property of %pOFn\n", child);
+		return err;
+	}
+
+	err = rpm_range_to_index(dev, &data->rpm_range[i], maxrpm);
+	if (err) {
+		dev_err(dev, "invalid max-rpm %d of %pOFn\n", maxrpm, child);
+		return err;
+	}
+	data->max_rpm[i] = maxrpm;
+
+	err = of_property_read_u32(child, "target-rpm", &val);
+	/* Use provided target RPM else default to maxrpm */
+	if (!err)
+		data->target_rpm[i] = val;
+	else
+		data->target_rpm[i] = maxrpm;
+
+	return 0;
+}
+
+static int max6639_probe_from_dt(struct i2c_client *client,
+				 struct max6639_data *data)
+{
+	struct device *dev = &client->dev;
+	const struct device_node *np = dev->of_node;
+	struct device_node *child;
+	int err;
+
+	/* Compatible with non-DT platforms */
+	if (!np)
+		return 0;
+
+	for_each_child_of_node(np, child) {
+		if (strcmp(child->name, "fan"))
+			continue;
+
+		err = max6639_probe_child_from_dt(client, child, data);
+		if (err) {
+			of_node_put(child);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
 static int max6639_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
 	struct max6639_data *data;
 	struct device *hwmon_dev;
-	int err;
+	int err, i;
 
 	data = devm_kzalloc(dev, sizeof(struct max6639_data), GFP_KERNEL);
 	if (!data)
@@ -539,9 +620,11 @@ static int max6639_probe(struct i2c_client *client)
 
 	data->reg = devm_regulator_get_optional(dev, "fan");
 	if (IS_ERR(data->reg)) {
-		if (PTR_ERR(data->reg) != -ENODEV)
-			return PTR_ERR(data->reg);
-
+		if (PTR_ERR(data->reg) != -ENODEV) {
+			err = (int)PTR_ERR(data->reg);
+			return dev_err_probe(dev, err,
+					     "Failed looking up fan supply\n");
+		}
 		data->reg = NULL;
 	} else {
 		/* Spin up fans */
@@ -560,6 +643,22 @@ static int max6639_probe(struct i2c_client *client)
 
 	mutex_init(&data->update_lock);
 
+	/* Below are defaults later overridden by DT properties */
+	for (i = 0; i < 2; i++) {
+		/* 4000 RPM */
+		data->rpm_range[i] = 1;
+		data->ppr[i] = 2;
+		/* Max. temp. 80C/90C/100C */
+		data->temp_therm[i] = 80;
+		data->temp_alert[i] = 90;
+		data->temp_ot[i] = 100;
+	}
+
+	/* Probe from DT to get configuration */
+	err = max6639_probe_from_dt(client, data);
+	if (err)
+		return err;
+
 	/* Initialize the max6639 chip */
 	err = max6639_init_client(client, data);
 	if (err < 0)
@@ -571,6 +670,7 @@ static int max6639_probe(struct i2c_client *client)
 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }
 
+#if IS_ENABLED(CONFIG_PM_SLEEP)
 static int max6639_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
@@ -608,6 +708,7 @@ static int max6639_resume(struct device *dev)
 	return i2c_smbus_write_byte_data(client,
 			MAX6639_REG_GCONFIG, ret & ~MAX6639_GCONFIG_STANDBY);
 }
+#endif
 
 static const struct i2c_device_id max6639_id[] = {
 	{"max6639", 0},
@@ -616,13 +717,22 @@ static const struct i2c_device_id max6639_id[] = {
 
 MODULE_DEVICE_TABLE(i2c, max6639_id);
 
-static DEFINE_SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);
+#ifdef CONFIG_OF
+static const struct of_device_id maxim_of_platform_match[] = {
+	{.compatible = "maxim,max6639"},
+	{},
+};
+MODULE_DEVICE_TABLE(of, maxim_of_platform_match);
+#endif
+
+static SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);
 
 static struct i2c_driver max6639_driver = {
 	.class = I2C_CLASS_HWMON,
 	.driver = {
 		   .name = "max6639",
 		   .pm = pm_sleep_ptr(&max6639_pm_ops),
+		   .of_match_table = of_match_ptr(maxim_of_platform_match),
 		   },
 	.probe_new = max6639_probe,
 	.id_table = max6639_id,
diff --git a/include/linux/platform_data/max6639.h b/include/linux/platform_data/max6639.h
deleted file mode 100644
index 65bfdb4fdc15..000000000000
--- a/include/linux/platform_data/max6639.h
+++ /dev/null
@@ -1,15 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _LINUX_MAX6639_H
-#define _LINUX_MAX6639_H
-
-#include <linux/types.h>
-
-/* platform data for the MAX6639 temperature sensor and fan control */
-
-struct max6639_platform_data {
-	bool pwm_polarity;	/* Polarity low (0) or high (1, default) */
-	int ppr;		/* Pulses per rotation 1..4 (default == 2) */
-	int rpm_range;		/* 2000, 4000 (default), 8000 or 16000 */
-};
-
-#endif /* _LINUX_MAX6639_H */
-- 
2.37.3

Re: [PATCH v7 3/4] hwmon: (max6639) Change from pdata to dt configuration

[Guenter Roeck]

On Mon, Nov 21, 2022 at 01:29:31PM +0100, Naresh Solanki wrote:
> max6639_platform_data is not used by any in-kernel driver and does not
> address the MAX6639 fans separately.
> Move to device tree configuration with explicit properties to configure
> each fan.
> 

This patch does way more than that.

> Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> ---
>  drivers/hwmon/max6639.c               | 246 +++++++++++++++++++-------
>  include/linux/platform_data/max6639.h |  15 --
>  2 files changed, 178 insertions(+), 83 deletions(-)
>  delete mode 100644 include/linux/platform_data/max6639.h
> 
> diff --git a/drivers/hwmon/max6639.c b/drivers/hwmon/max6639.c
> index 9b895402c80d..feafa3511297 100644
> --- a/drivers/hwmon/max6639.c
> +++ b/drivers/hwmon/max6639.c
> @@ -19,7 +19,6 @@
>  #include <linux/hwmon-sysfs.h>
>  #include <linux/err.h>
>  #include <linux/mutex.h>
> -#include <linux/platform_data/max6639.h>
>  
>  /* Addresses to scan */
>  static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
> @@ -54,9 +53,12 @@ static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
>  #define MAX6639_GCONFIG_PWM_FREQ_HI		0x08
>  
>  #define MAX6639_FAN_CONFIG1_PWM			0x80
> -
> +#define MAX6639_REG_FAN_CONFIG2a_PWM_POL	0x02
>  #define MAX6639_FAN_CONFIG3_THERM_FULL_SPEED	0x40
> +#define MAX6639_FAN_CONFIG3_FREQ_MASK		0x03
> +#define MAX6639_REG_TARGTDUTY_SLOT		120
>  
> +/* Tach supported range. This internally controls tach frequency */
>  static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };
>  
>  #define FAN_FROM_REG(val, rpm_range)	((val) == 0 || (val) == 255 ? \
> @@ -76,18 +78,21 @@ struct max6639_data {
>  	u16 temp[2];		/* Temperature, in 1/8 C, 0..255 C */
>  	bool temp_fault[2];	/* Detected temperature diode failure */
>  	u8 fan[2];		/* Register value: TACH count for fans >=30 */
> +	u32 target_rpm[2];
> +	u32 max_rpm[2];
> +	u8 pwm[2];
> +
>  	u8 status;		/* Detected channel alarms and fan failures */
>  
>  	/* Register values only written to */
> -	u8 pwm[2];		/* Register value: Duty cycle 0..120 */
>  	u8 temp_therm[2];	/* THERM Temperature, 0..255 C (->_max) */
>  	u8 temp_alert[2];	/* ALERT Temperature, 0..255 C (->_crit) */
>  	u8 temp_ot[2];		/* OT Temperature, 0..255 C (->_emergency) */
>  
>  	/* Register values initialized only once */
> -	u8 ppr;			/* Pulses per rotation 0..3 for 1..4 ppr */
> -	u8 rpm_range;		/* Index in above rpm_ranges table */
> -
> +	u8 ppr[2];		/* Pulses per rotation 0..3 for 1..4 ppr */
> +	u8 rpm_range[2];	/* Index in above rpm_ranges table */
> +	u8 pwm_polarity[2];
>  	/* Optional regulator for FAN supply */
>  	struct regulator *reg;
>  };
> @@ -282,6 +287,7 @@ static ssize_t pwm_show(struct device *dev, struct device_attribute *dev_attr,
>  	struct max6639_data *data = dev_get_drvdata(dev);
>  
>  	return sprintf(buf, "%d\n", data->pwm[attr->index] * 255 / 120);
> +

Unnecessary and wrong whitespace change.

>  }
>  
>  static ssize_t pwm_store(struct device *dev,
> @@ -302,10 +308,10 @@ static ssize_t pwm_store(struct device *dev,
>  
>  	mutex_lock(&data->update_lock);
>  	data->pwm[attr->index] = (u8)(val * 120 / 255);
> -	i2c_smbus_write_byte_data(client,
> -				  MAX6639_REG_TARGTDUTY(attr->index),
> -				  data->pwm[attr->index]);
> +	i2c_smbus_write_byte_data(client, MAX6639_REG_TARGTDUTY(attr->index),
> +				 data->pwm[attr->index]);
>  	mutex_unlock(&data->update_lock);
> +
>  	return count;

Unnecessary formatting change. You may not like the original formatting,
but that is no reason to change it.

>  }
>  
> @@ -319,7 +325,7 @@ static ssize_t fan_input_show(struct device *dev,
>  		return PTR_ERR(data);
>  
>  	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[attr->index],
> -		       data->rpm_range));
> +		       data->rpm_range[attr->index]));
>  }
>  
>  static ssize_t alarm_show(struct device *dev,
> @@ -386,29 +392,40 @@ static struct attribute *max6639_attrs[] = {
>  ATTRIBUTE_GROUPS(max6639);
>  
>  /*
> - *  returns respective index in rpm_ranges table
> - *  1 by default on invalid range
> + *  Get respective index in rpm_ranges table
>   */
> -static int rpm_range_to_reg(int range)
> +static int rpm_range_to_index(struct device *dev, u8 *index, int rpm)
>  {
> -	int i;
> -
> -	for (i = 0; i < ARRAY_SIZE(rpm_ranges); i++) {
> -		if (rpm_ranges[i] == range)
> -			return i;
> +	if (rpm < 0)
> +		return -EINVAL;
> +
> +	/* Set index based on chip support */
> +	switch (rpm) {
> +	case 0 ... 2000:
> +		*index = 0;
> +		break;
> +	case 2001 ... 4000:
> +		*index = 1;
> +		break;
> +	case 4001 ... 8000:
> +		*index = 2;
> +		break;
> +	case 8001 ... 16000:
> +		*index = 3;
> +		break;
> +	default:
> +		/* Use max range for higher RPM */
> +		dev_warn(dev,
> +		    "RPM higher than supported range. Default to 16000 RPM");
> +		*index = 3;
>  	}
> -
> -	return 1; /* default: 4000 RPM */
> +	return 0;

The above changes are unrelated to $subject. Also, the same could be
accomplished by varying the range check in the for loop, making the
change POV. The warning is both unacceptable and unnecessary.

>  }
>  
>  static int max6639_init_client(struct i2c_client *client,
>  			       struct max6639_data *data)
>  {
> -	struct max6639_platform_data *max6639_info =
> -		dev_get_platdata(&client->dev);
> -	int i;
> -	int rpm_range = 1; /* default: 4000 RPM */
> -	int err;
> +	int i, err;
>  
>  	/* Reset chip to default values, see below for GCONFIG setup */
>  	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
> @@ -416,51 +433,29 @@ static int max6639_init_client(struct i2c_client *client,
>  	if (err)
>  		goto exit;
>  
> -	/* Fans pulse per revolution is 2 by default */
> -	if (max6639_info && max6639_info->ppr > 0 &&
> -			max6639_info->ppr < 5)
> -		data->ppr = max6639_info->ppr;
> -	else
> -		data->ppr = 2;
> -	data->ppr -= 1;
> -
> -	if (max6639_info)
> -		rpm_range = rpm_range_to_reg(max6639_info->rpm_range);
> -	data->rpm_range = rpm_range;
> -
>  	for (i = 0; i < 2; i++) {
>  
>  		/* Set Fan pulse per revolution */
> -		err = i2c_smbus_write_byte_data(client,
> -				MAX6639_REG_FAN_PPR(i),
> -				data->ppr << 6);
> +		err = i2c_smbus_write_byte_data(client,	MAX6639_REG_FAN_PPR(i),
> +						data->ppr[i] << 6);
>  		if (err)
>  			goto exit;
>  
>  		/* Fans config PWM, RPM */
>  		err = i2c_smbus_write_byte_data(client,
> -			MAX6639_REG_FAN_CONFIG1(i),
> -			MAX6639_FAN_CONFIG1_PWM | rpm_range);
> -		if (err)
> -			goto exit;
> -
> -		/* Fans PWM polarity high by default */
> -		if (max6639_info && max6639_info->pwm_polarity == 0)
> -			err = i2c_smbus_write_byte_data(client,
> -				MAX6639_REG_FAN_CONFIG2a(i), 0x00);
> -		else
> -			err = i2c_smbus_write_byte_data(client,
> -				MAX6639_REG_FAN_CONFIG2a(i), 0x02);
> +						MAX6639_REG_FAN_CONFIG1(i),
> +						MAX6639_FAN_CONFIG1_PWM |
> +						data->rpm_range[i]);

The above change silently drops the configuration of
MAX6639_REG_FAN_CONFIG2a, which is puzzling since the patch
also introduces MAX6639_REG_FAN_CONFIG2a_PWM_POL which isn't
used. I don't see what this has to do with $subject, and the
lack of explanation is not really reassuring.

>  		if (err)
>  			goto exit;
>  
>  		/*
> -		 * /THERM full speed enable,
> +		 * /THERM full speed disable,

Change unrelated to $subject and possibly unexpected results
for users of this driver.

>  		 * PWM frequency 25kHz, see also GCONFIG below
>  		 */
>  		err = i2c_smbus_write_byte_data(client,
> -			MAX6639_REG_FAN_CONFIG3(i),
> -			MAX6639_FAN_CONFIG3_THERM_FULL_SPEED | 0x03);
> +						MAX6639_REG_FAN_CONFIG3(i),
> +						0x03);
>  		if (err)
>  			goto exit;
>  
> @@ -469,31 +464,34 @@ static int max6639_init_client(struct i2c_client *client,
>  		data->temp_alert[i] = 90;
>  		data->temp_ot[i] = 100;
>  		err = i2c_smbus_write_byte_data(client,
> -				MAX6639_REG_THERM_LIMIT(i),
> -				data->temp_therm[i]);
> +						MAX6639_REG_THERM_LIMIT(i),
> +						data->temp_therm[i]);
>  		if (err)
>  			goto exit;
>  		err = i2c_smbus_write_byte_data(client,
> -				MAX6639_REG_ALERT_LIMIT(i),
> -				data->temp_alert[i]);
> +						MAX6639_REG_ALERT_LIMIT(i),
> +						data->temp_alert[i]);

Unrelated formatting changes above. Such changes just obfuscate functional
changes made in the patch and are unacceptable. If you want to fix
checkpatch issues, do it in a separate patch.

I am stopping the review here. In the future, please refrain from making
unrelated changes. One logical change per patch, please.

Guenter

>  		if (err)
>  			goto exit;
>  		err = i2c_smbus_write_byte_data(client,
> -				MAX6639_REG_OT_LIMIT(i), data->temp_ot[i]);
> +						MAX6639_REG_OT_LIMIT(i),
> +						data->temp_ot[i]);
>  		if (err)
>  			goto exit;
>  
>  		/* PWM 120/120 (i.e. 100%) */
> -		data->pwm[i] = 120;
> -		err = i2c_smbus_write_byte_data(client,
> -				MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
> +		data->pwm[i] = data->target_rpm[i];
> +		err = i2c_smbus_write_byte_data(client, MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
> +
>  		if (err)
>  			goto exit;
> +
>  	}
>  	/* Start monitoring */
>  	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
>  		MAX6639_GCONFIG_DISABLE_TIMEOUT | MAX6639_GCONFIG_CH2_LOCAL |
>  		MAX6639_GCONFIG_PWM_FREQ_HI);
> +
>  exit:
>  	return err;
>  }
> @@ -524,12 +522,95 @@ static void max6639_regulator_disable(void *data)
>  	regulator_disable(data);
>  }
>  
> +static int max6639_probe_child_from_dt(struct i2c_client *client,
> +				      struct device_node *child,
> +				      struct max6639_data *data)
> +
> +{
> +	struct device *dev = &client->dev;
> +	u32 i, maxrpm;
> +	int val, err;
> +
> +	err = of_property_read_u32(child, "reg", &i);
> +	if (err) {
> +		dev_err(dev, "missing reg property of %pOFn\n", child);
> +		return err;
> +	}
> +
> +	if (i >= 2) {
> +		dev_err(dev, "invalid reg %d of %pOFn\n", i, child);
> +		return -EINVAL;
> +	}
> +
> +	err = of_property_read_u32(child, "pulses-per-revolution", &val);
> +	if (err) {
> +		dev_err(dev, "missing pulses-per-revolution property of %pOFn",
> +			child);
> +		return err;
> +	}
> +
> +	if (val < 0 || val > 5) {
> +		dev_err(dev, "invalid pulses-per-revolution %d of %pOFn\n", val,
> +			child);
> +		return -EINVAL;
> +	}
> +	data->ppr[i] = val;
> +
> +	err = of_property_read_u32(child, "max-rpm", &maxrpm);
> +	if (err) {
> +		dev_err(dev, "missing max-rpm property of %pOFn\n", child);
> +		return err;
> +	}
> +
> +	err = rpm_range_to_index(dev, &data->rpm_range[i], maxrpm);
> +	if (err) {
> +		dev_err(dev, "invalid max-rpm %d of %pOFn\n", maxrpm, child);
> +		return err;
> +	}
> +	data->max_rpm[i] = maxrpm;
> +
> +	err = of_property_read_u32(child, "target-rpm", &val);
> +	/* Use provided target RPM else default to maxrpm */
> +	if (!err)
> +		data->target_rpm[i] = val;
> +	else
> +		data->target_rpm[i] = maxrpm;
> +
> +	return 0;
> +}
> +
> +static int max6639_probe_from_dt(struct i2c_client *client,
> +				 struct max6639_data *data)
> +{
> +	struct device *dev = &client->dev;
> +	const struct device_node *np = dev->of_node;
> +	struct device_node *child;
> +	int err;
> +
> +	/* Compatible with non-DT platforms */
> +	if (!np)
> +		return 0;
> +
> +	for_each_child_of_node(np, child) {
> +		if (strcmp(child->name, "fan"))
> +			continue;
> +
> +		err = max6639_probe_child_from_dt(client, child, data);
> +		if (err) {
> +			of_node_put(child);
> +			return err;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
>  static int max6639_probe(struct i2c_client *client)
>  {
>  	struct device *dev = &client->dev;
>  	struct max6639_data *data;
>  	struct device *hwmon_dev;
> -	int err;
> +	int err, i;
>  
>  	data = devm_kzalloc(dev, sizeof(struct max6639_data), GFP_KERNEL);
>  	if (!data)
> @@ -539,9 +620,11 @@ static int max6639_probe(struct i2c_client *client)
>  
>  	data->reg = devm_regulator_get_optional(dev, "fan");
>  	if (IS_ERR(data->reg)) {
> -		if (PTR_ERR(data->reg) != -ENODEV)
> -			return PTR_ERR(data->reg);
> -
> +		if (PTR_ERR(data->reg) != -ENODEV) {
> +			err = (int)PTR_ERR(data->reg);
> +			return dev_err_probe(dev, err,
> +					     "Failed looking up fan supply\n");
> +		}
>  		data->reg = NULL;
>  	} else {
>  		/* Spin up fans */
> @@ -560,6 +643,22 @@ static int max6639_probe(struct i2c_client *client)
>  
>  	mutex_init(&data->update_lock);
>  
> +	/* Below are defaults later overridden by DT properties */
> +	for (i = 0; i < 2; i++) {
> +		/* 4000 RPM */
> +		data->rpm_range[i] = 1;
> +		data->ppr[i] = 2;
> +		/* Max. temp. 80C/90C/100C */
> +		data->temp_therm[i] = 80;
> +		data->temp_alert[i] = 90;
> +		data->temp_ot[i] = 100;
> +	}
> +
> +	/* Probe from DT to get configuration */
> +	err = max6639_probe_from_dt(client, data);
> +	if (err)
> +		return err;
> +
>  	/* Initialize the max6639 chip */
>  	err = max6639_init_client(client, data);
>  	if (err < 0)
> @@ -571,6 +670,7 @@ static int max6639_probe(struct i2c_client *client)
>  	return PTR_ERR_OR_ZERO(hwmon_dev);
>  }
>  
> +#if IS_ENABLED(CONFIG_PM_SLEEP)
>  static int max6639_suspend(struct device *dev)
>  {
>  	struct i2c_client *client = to_i2c_client(dev);
> @@ -608,6 +708,7 @@ static int max6639_resume(struct device *dev)
>  	return i2c_smbus_write_byte_data(client,
>  			MAX6639_REG_GCONFIG, ret & ~MAX6639_GCONFIG_STANDBY);
>  }
> +#endif
>  
>  static const struct i2c_device_id max6639_id[] = {
>  	{"max6639", 0},
> @@ -616,13 +717,22 @@ static const struct i2c_device_id max6639_id[] = {
>  
>  MODULE_DEVICE_TABLE(i2c, max6639_id);
>  
> -static DEFINE_SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);
> +#ifdef CONFIG_OF
> +static const struct of_device_id maxim_of_platform_match[] = {
> +	{.compatible = "maxim,max6639"},
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, maxim_of_platform_match);
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);
>  
>  static struct i2c_driver max6639_driver = {
>  	.class = I2C_CLASS_HWMON,
>  	.driver = {
>  		   .name = "max6639",
>  		   .pm = pm_sleep_ptr(&max6639_pm_ops),
> +		   .of_match_table = of_match_ptr(maxim_of_platform_match),
>  		   },
>  	.probe_new = max6639_probe,
>  	.id_table = max6639_id,
> diff --git a/include/linux/platform_data/max6639.h b/include/linux/platform_data/max6639.h
> deleted file mode 100644
> index 65bfdb4fdc15..000000000000
> --- a/include/linux/platform_data/max6639.h
> +++ /dev/null
> @@ -1,15 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -#ifndef _LINUX_MAX6639_H
> -#define _LINUX_MAX6639_H
> -
> -#include <linux/types.h>
> -
> -/* platform data for the MAX6639 temperature sensor and fan control */
> -
> -struct max6639_platform_data {
> -	bool pwm_polarity;	/* Polarity low (0) or high (1, default) */
> -	int ppr;		/* Pulses per rotation 1..4 (default == 2) */
> -	int rpm_range;		/* 2000, 4000 (default), 8000 or 16000 */
> -};
> -
> -#endif /* _LINUX_MAX6639_H */

Re: [PATCH v7 3/4] hwmon: (max6639) Change from pdata to dt configuration

[Naresh Solanki]

Hi Guenter,

On 25-11-2022 09:48 pm, Guenter Roeck wrote:
> On Mon, Nov 21, 2022 at 01:29:31PM +0100, Naresh Solanki wrote:
>> max6639_platform_data is not used by any in-kernel driver and does not
>> address the MAX6639 fans separately.
>> Move to device tree configuration with explicit properties to configure
>> each fan.
>>
> 
> This patch does way more than that.
> 
>> Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
>> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
>> ---
>>   drivers/hwmon/max6639.c               | 246 +++++++++++++++++++-------
>>   include/linux/platform_data/max6639.h |  15 --
>>   2 files changed, 178 insertions(+), 83 deletions(-)
>>   delete mode 100644 include/linux/platform_data/max6639.h
>>
>> diff --git a/drivers/hwmon/max6639.c b/drivers/hwmon/max6639.c
>> index 9b895402c80d..feafa3511297 100644
>> --- a/drivers/hwmon/max6639.c
>> +++ b/drivers/hwmon/max6639.c
>> @@ -19,7 +19,6 @@
>>   #include <linux/hwmon-sysfs.h>
>>   #include <linux/err.h>
>>   #include <linux/mutex.h>
>> -#include <linux/platform_data/max6639.h>
>>   
>>   /* Addresses to scan */
>>   static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
>> @@ -54,9 +53,12 @@ static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
>>   #define MAX6639_GCONFIG_PWM_FREQ_HI		0x08
>>   
>>   #define MAX6639_FAN_CONFIG1_PWM			0x80
>> -
>> +#define MAX6639_REG_FAN_CONFIG2a_PWM_POL	0x02
>>   #define MAX6639_FAN_CONFIG3_THERM_FULL_SPEED	0x40
>> +#define MAX6639_FAN_CONFIG3_FREQ_MASK		0x03
>> +#define MAX6639_REG_TARGTDUTY_SLOT		120
>>   
>> +/* Tach supported range. This internally controls tach frequency */
>>   static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };
>>   
>>   #define FAN_FROM_REG(val, rpm_range)	((val) == 0 || (val) == 255 ? \
>> @@ -76,18 +78,21 @@ struct max6639_data {
>>   	u16 temp[2];		/* Temperature, in 1/8 C, 0..255 C */
>>   	bool temp_fault[2];	/* Detected temperature diode failure */
>>   	u8 fan[2];		/* Register value: TACH count for fans >=30 */
>> +	u32 target_rpm[2];
>> +	u32 max_rpm[2];
>> +	u8 pwm[2];
>> +
>>   	u8 status;		/* Detected channel alarms and fan failures */
>>   
>>   	/* Register values only written to */
>> -	u8 pwm[2];		/* Register value: Duty cycle 0..120 */
>>   	u8 temp_therm[2];	/* THERM Temperature, 0..255 C (->_max) */
>>   	u8 temp_alert[2];	/* ALERT Temperature, 0..255 C (->_crit) */
>>   	u8 temp_ot[2];		/* OT Temperature, 0..255 C (->_emergency) */
>>   
>>   	/* Register values initialized only once */
>> -	u8 ppr;			/* Pulses per rotation 0..3 for 1..4 ppr */
>> -	u8 rpm_range;		/* Index in above rpm_ranges table */
>> -
>> +	u8 ppr[2];		/* Pulses per rotation 0..3 for 1..4 ppr */
>> +	u8 rpm_range[2];	/* Index in above rpm_ranges table */
>> +	u8 pwm_polarity[2];
>>   	/* Optional regulator for FAN supply */
>>   	struct regulator *reg;
>>   };
>> @@ -282,6 +287,7 @@ static ssize_t pwm_show(struct device *dev, struct device_attribute *dev_attr,
>>   	struct max6639_data *data = dev_get_drvdata(dev);
>>   
>>   	return sprintf(buf, "%d\n", data->pwm[attr->index] * 255 / 120);
>> +
> 
> Unnecessary and wrong whitespace change.
> 
>>   }
>>   
>>   static ssize_t pwm_store(struct device *dev,
>> @@ -302,10 +308,10 @@ static ssize_t pwm_store(struct device *dev,
>>   
>>   	mutex_lock(&data->update_lock);
>>   	data->pwm[attr->index] = (u8)(val * 120 / 255);
>> -	i2c_smbus_write_byte_data(client,
>> -				  MAX6639_REG_TARGTDUTY(attr->index),
>> -				  data->pwm[attr->index]);
>> +	i2c_smbus_write_byte_data(client, MAX6639_REG_TARGTDUTY(attr->index),
>> +				 data->pwm[attr->index]);
>>   	mutex_unlock(&data->update_lock);
>> +
>>   	return count;
> 
> Unnecessary formatting change. You may not like the original formatting,
> but that is no reason to change it.
> 
>>   }
>>   
>> @@ -319,7 +325,7 @@ static ssize_t fan_input_show(struct device *dev,
>>   		return PTR_ERR(data);
>>   
>>   	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[attr->index],
>> -		       data->rpm_range));
>> +		       data->rpm_range[attr->index]));
>>   }
>>   
>>   static ssize_t alarm_show(struct device *dev,
>> @@ -386,29 +392,40 @@ static struct attribute *max6639_attrs[] = {
>>   ATTRIBUTE_GROUPS(max6639);
>>   
>>   /*
>> - *  returns respective index in rpm_ranges table
>> - *  1 by default on invalid range
>> + *  Get respective index in rpm_ranges table
>>    */
>> -static int rpm_range_to_reg(int range)
>> +static int rpm_range_to_index(struct device *dev, u8 *index, int rpm)
>>   {
>> -	int i;
>> -
>> -	for (i = 0; i < ARRAY_SIZE(rpm_ranges); i++) {
>> -		if (rpm_ranges[i] == range)
>> -			return i;
>> +	if (rpm < 0)
>> +		return -EINVAL;
>> +
>> +	/* Set index based on chip support */
>> +	switch (rpm) {
>> +	case 0 ... 2000:
>> +		*index = 0;
>> +		break;
>> +	case 2001 ... 4000:
>> +		*index = 1;
>> +		break;
>> +	case 4001 ... 8000:
>> +		*index = 2;
>> +		break;
>> +	case 8001 ... 16000:
>> +		*index = 3;
>> +		break;
>> +	default:
>> +		/* Use max range for higher RPM */
>> +		dev_warn(dev,
>> +		    "RPM higher than supported range. Default to 16000 RPM");
>> +		*index = 3;
>>   	}
>> -
>> -	return 1; /* default: 4000 RPM */
>> +	return 0;
> 
> The above changes are unrelated to $subject. Also, the same could be
> accomplished by varying the range check in the for loop, making the
> change POV. The warning is both unacceptable and unnecessary.
> 
>>   }
>>   
>>   static int max6639_init_client(struct i2c_client *client,
>>   			       struct max6639_data *data)
>>   {
>> -	struct max6639_platform_data *max6639_info =
>> -		dev_get_platdata(&client->dev);
>> -	int i;
>> -	int rpm_range = 1; /* default: 4000 RPM */
>> -	int err;
>> +	int i, err;
>>   
>>   	/* Reset chip to default values, see below for GCONFIG setup */
>>   	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
>> @@ -416,51 +433,29 @@ static int max6639_init_client(struct i2c_client *client,
>>   	if (err)
>>   		goto exit;
>>   
>> -	/* Fans pulse per revolution is 2 by default */
>> -	if (max6639_info && max6639_info->ppr > 0 &&
>> -			max6639_info->ppr < 5)
>> -		data->ppr = max6639_info->ppr;
>> -	else
>> -		data->ppr = 2;
>> -	data->ppr -= 1;
>> -
>> -	if (max6639_info)
>> -		rpm_range = rpm_range_to_reg(max6639_info->rpm_range);
>> -	data->rpm_range = rpm_range;
>> -
>>   	for (i = 0; i < 2; i++) {
>>   
>>   		/* Set Fan pulse per revolution */
>> -		err = i2c_smbus_write_byte_data(client,
>> -				MAX6639_REG_FAN_PPR(i),
>> -				data->ppr << 6);
>> +		err = i2c_smbus_write_byte_data(client,	MAX6639_REG_FAN_PPR(i),
>> +						data->ppr[i] << 6);
>>   		if (err)
>>   			goto exit;
>>   
>>   		/* Fans config PWM, RPM */
>>   		err = i2c_smbus_write_byte_data(client,
>> -			MAX6639_REG_FAN_CONFIG1(i),
>> -			MAX6639_FAN_CONFIG1_PWM | rpm_range);
>> -		if (err)
>> -			goto exit;
>> -
>> -		/* Fans PWM polarity high by default */
>> -		if (max6639_info && max6639_info->pwm_polarity == 0)
>> -			err = i2c_smbus_write_byte_data(client,
>> -				MAX6639_REG_FAN_CONFIG2a(i), 0x00);
>> -		else
>> -			err = i2c_smbus_write_byte_data(client,
>> -				MAX6639_REG_FAN_CONFIG2a(i), 0x02);
>> +						MAX6639_REG_FAN_CONFIG1(i),
>> +						MAX6639_FAN_CONFIG1_PWM |
>> +						data->rpm_range[i]);
> 
> The above change silently drops the configuration of
> MAX6639_REG_FAN_CONFIG2a, which is puzzling since the patch
> also introduces MAX6639_REG_FAN_CONFIG2a_PWM_POL which isn't
> used. I don't see what this has to do with $subject, and the
> lack of explanation is not really reassuring.
> 
>>   		if (err)
>>   			goto exit;
>>   
>>   		/*
>> -		 * /THERM full speed enable,
>> +		 * /THERM full speed disable,
> 
> Change unrelated to $subject and possibly unexpected results
> for users of this driver.
> 
>>   		 * PWM frequency 25kHz, see also GCONFIG below
>>   		 */
>>   		err = i2c_smbus_write_byte_data(client,
>> -			MAX6639_REG_FAN_CONFIG3(i),
>> -			MAX6639_FAN_CONFIG3_THERM_FULL_SPEED | 0x03);
>> +						MAX6639_REG_FAN_CONFIG3(i),
>> +						0x03);
>>   		if (err)
>>   			goto exit;
>>   
>> @@ -469,31 +464,34 @@ static int max6639_init_client(struct i2c_client *client,
>>   		data->temp_alert[i] = 90;
>>   		data->temp_ot[i] = 100;
>>   		err = i2c_smbus_write_byte_data(client,
>> -				MAX6639_REG_THERM_LIMIT(i),
>> -				data->temp_therm[i]);
>> +						MAX6639_REG_THERM_LIMIT(i),
>> +						data->temp_therm[i]);
>>   		if (err)
>>   			goto exit;
>>   		err = i2c_smbus_write_byte_data(client,
>> -				MAX6639_REG_ALERT_LIMIT(i),
>> -				data->temp_alert[i]);
>> +						MAX6639_REG_ALERT_LIMIT(i),
>> +						data->temp_alert[i]);
> 
> Unrelated formatting changes above. Such changes just obfuscate functional
> changes made in the patch and are unacceptable. If you want to fix
> checkpatch issues, do it in a separate patch.
> 
> I am stopping the review here. In the future, please refrain from making
> unrelated changes. One logical change per patch, please.
Sure. Thanks.
> 
> Guenter
> 
>>   		if (err)
>>   			goto exit;
>>   		err = i2c_smbus_write_byte_data(client,
>> -				MAX6639_REG_OT_LIMIT(i), data->temp_ot[i]);
>> +						MAX6639_REG_OT_LIMIT(i),
>> +						data->temp_ot[i]);
>>   		if (err)
>>   			goto exit;
>>   
>>   		/* PWM 120/120 (i.e. 100%) */
>> -		data->pwm[i] = 120;
>> -		err = i2c_smbus_write_byte_data(client,
>> -				MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
>> +		data->pwm[i] = data->target_rpm[i];
>> +		err = i2c_smbus_write_byte_data(client, MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
>> +
>>   		if (err)
>>   			goto exit;
>> +
>>   	}
>>   	/* Start monitoring */
>>   	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
>>   		MAX6639_GCONFIG_DISABLE_TIMEOUT | MAX6639_GCONFIG_CH2_LOCAL |
>>   		MAX6639_GCONFIG_PWM_FREQ_HI);
>> +
>>   exit:
>>   	return err;
>>   }
>> @@ -524,12 +522,95 @@ static void max6639_regulator_disable(void *data)
>>   	regulator_disable(data);
>>   }
>>   
>> +static int max6639_probe_child_from_dt(struct i2c_client *client,
>> +				      struct device_node *child,
>> +				      struct max6639_data *data)
>> +
>> +{
>> +	struct device *dev = &client->dev;
>> +	u32 i, maxrpm;
>> +	int val, err;
>> +
>> +	err = of_property_read_u32(child, "reg", &i);
>> +	if (err) {
>> +		dev_err(dev, "missing reg property of %pOFn\n", child);
>> +		return err;
>> +	}
>> +
>> +	if (i >= 2) {
>> +		dev_err(dev, "invalid reg %d of %pOFn\n", i, child);
>> +		return -EINVAL;
>> +	}
>> +
>> +	err = of_property_read_u32(child, "pulses-per-revolution", &val);
>> +	if (err) {
>> +		dev_err(dev, "missing pulses-per-revolution property of %pOFn",
>> +			child);
>> +		return err;
>> +	}
>> +
>> +	if (val < 0 || val > 5) {
>> +		dev_err(dev, "invalid pulses-per-revolution %d of %pOFn\n", val,
>> +			child);
>> +		return -EINVAL;
>> +	}
>> +	data->ppr[i] = val;
>> +
>> +	err = of_property_read_u32(child, "max-rpm", &maxrpm);
>> +	if (err) {
>> +		dev_err(dev, "missing max-rpm property of %pOFn\n", child);
>> +		return err;
>> +	}
>> +
>> +	err = rpm_range_to_index(dev, &data->rpm_range[i], maxrpm);
>> +	if (err) {
>> +		dev_err(dev, "invalid max-rpm %d of %pOFn\n", maxrpm, child);
>> +		return err;
>> +	}
>> +	data->max_rpm[i] = maxrpm;
>> +
>> +	err = of_property_read_u32(child, "target-rpm", &val);
>> +	/* Use provided target RPM else default to maxrpm */
>> +	if (!err)
>> +		data->target_rpm[i] = val;
>> +	else
>> +		data->target_rpm[i] = maxrpm;
>> +
>> +	return 0;
>> +}
>> +
>> +static int max6639_probe_from_dt(struct i2c_client *client,
>> +				 struct max6639_data *data)
>> +{
>> +	struct device *dev = &client->dev;
>> +	const struct device_node *np = dev->of_node;
>> +	struct device_node *child;
>> +	int err;
>> +
>> +	/* Compatible with non-DT platforms */
>> +	if (!np)
>> +		return 0;
>> +
>> +	for_each_child_of_node(np, child) {
>> +		if (strcmp(child->name, "fan"))
>> +			continue;
>> +
>> +		err = max6639_probe_child_from_dt(client, child, data);
>> +		if (err) {
>> +			of_node_put(child);
>> +			return err;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>>   static int max6639_probe(struct i2c_client *client)
>>   {
>>   	struct device *dev = &client->dev;
>>   	struct max6639_data *data;
>>   	struct device *hwmon_dev;
>> -	int err;
>> +	int err, i;
>>   
>>   	data = devm_kzalloc(dev, sizeof(struct max6639_data), GFP_KERNEL);
>>   	if (!data)
>> @@ -539,9 +620,11 @@ static int max6639_probe(struct i2c_client *client)
>>   
>>   	data->reg = devm_regulator_get_optional(dev, "fan");
>>   	if (IS_ERR(data->reg)) {
>> -		if (PTR_ERR(data->reg) != -ENODEV)
>> -			return PTR_ERR(data->reg);
>> -
>> +		if (PTR_ERR(data->reg) != -ENODEV) {
>> +			err = (int)PTR_ERR(data->reg);
>> +			return dev_err_probe(dev, err,
>> +					     "Failed looking up fan supply\n");
>> +		}
>>   		data->reg = NULL;
>>   	} else {
>>   		/* Spin up fans */
>> @@ -560,6 +643,22 @@ static int max6639_probe(struct i2c_client *client)
>>   
>>   	mutex_init(&data->update_lock);
>>   
>> +	/* Below are defaults later overridden by DT properties */
>> +	for (i = 0; i < 2; i++) {
>> +		/* 4000 RPM */
>> +		data->rpm_range[i] = 1;
>> +		data->ppr[i] = 2;
>> +		/* Max. temp. 80C/90C/100C */
>> +		data->temp_therm[i] = 80;
>> +		data->temp_alert[i] = 90;
>> +		data->temp_ot[i] = 100;
>> +	}
>> +
>> +	/* Probe from DT to get configuration */
>> +	err = max6639_probe_from_dt(client, data);
>> +	if (err)
>> +		return err;
>> +
>>   	/* Initialize the max6639 chip */
>>   	err = max6639_init_client(client, data);
>>   	if (err < 0)
>> @@ -571,6 +670,7 @@ static int max6639_probe(struct i2c_client *client)
>>   	return PTR_ERR_OR_ZERO(hwmon_dev);
>>   }
>>   
>> +#if IS_ENABLED(CONFIG_PM_SLEEP)
>>   static int max6639_suspend(struct device *dev)
>>   {
>>   	struct i2c_client *client = to_i2c_client(dev);
>> @@ -608,6 +708,7 @@ static int max6639_resume(struct device *dev)
>>   	return i2c_smbus_write_byte_data(client,
>>   			MAX6639_REG_GCONFIG, ret & ~MAX6639_GCONFIG_STANDBY);
>>   }
>> +#endif
>>   
>>   static const struct i2c_device_id max6639_id[] = {
>>   	{"max6639", 0},
>> @@ -616,13 +717,22 @@ static const struct i2c_device_id max6639_id[] = {
>>   
>>   MODULE_DEVICE_TABLE(i2c, max6639_id);
>>   
>> -static DEFINE_SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);
>> +#ifdef CONFIG_OF
>> +static const struct of_device_id maxim_of_platform_match[] = {
>> +	{.compatible = "maxim,max6639"},
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(of, maxim_of_platform_match);
>> +#endif
>> +
>> +static SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);
>>   
>>   static struct i2c_driver max6639_driver = {
>>   	.class = I2C_CLASS_HWMON,
>>   	.driver = {
>>   		   .name = "max6639",
>>   		   .pm = pm_sleep_ptr(&max6639_pm_ops),
>> +		   .of_match_table = of_match_ptr(maxim_of_platform_match),
>>   		   },
>>   	.probe_new = max6639_probe,
>>   	.id_table = max6639_id,
>> diff --git a/include/linux/platform_data/max6639.h b/include/linux/platform_data/max6639.h
>> deleted file mode 100644
>> index 65bfdb4fdc15..000000000000
>> --- a/include/linux/platform_data/max6639.h
>> +++ /dev/null
>> @@ -1,15 +0,0 @@
>> -/* SPDX-License-Identifier: GPL-2.0 */
>> -#ifndef _LINUX_MAX6639_H
>> -#define _LINUX_MAX6639_H
>> -
>> -#include <linux/types.h>
>> -
>> -/* platform data for the MAX6639 temperature sensor and fan control */
>> -
>> -struct max6639_platform_data {
>> -	bool pwm_polarity;	/* Polarity low (0) or high (1, default) */
>> -	int ppr;		/* Pulses per rotation 1..4 (default == 2) */
>> -	int rpm_range;		/* 2000, 4000 (default), 8000 or 16000 */
>> -};
>> -
>> -#endif /* _LINUX_MAX6639_H */
Regrads,
Naresh

[PATCH v7 4/4] hwmon: (max6639) Add pwm support

[Naresh Solanki]

Add pwm support for max6639. Also configure pwm fan speed based on pwm
provided in DT.

Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
---
 drivers/hwmon/Kconfig   |   1 +
 drivers/hwmon/max6639.c | 229 +++++++++++++++++++++++++++++++++++++---
 2 files changed, 216 insertions(+), 14 deletions(-)

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 3176c33af6c6..56d9004b7a38 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1115,6 +1115,7 @@ config SENSORS_MAX6621
 config SENSORS_MAX6639
 	tristate "Maxim MAX6639 sensor chip"
 	depends on I2C
+	depends on PWM
 	help
 	  If you say yes here you get support for the MAX6639
 	  sensor chips.
diff --git a/drivers/hwmon/max6639.c b/drivers/hwmon/max6639.c
index feafa3511297..5bfeee35abf0 100644
--- a/drivers/hwmon/max6639.c
+++ b/drivers/hwmon/max6639.c
@@ -19,6 +19,7 @@
 #include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
+#include <linux/pwm.h>
 
 /* Addresses to scan */
 static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
@@ -61,6 +62,10 @@ static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
 /* Tach supported range. This internally controls tach frequency */
 static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };
 
+/* Supported PWM frequency */
+static const unsigned int freq_table[] = { 20, 33, 50, 100, 5000, 8333, 12500,
+					   25000 };
+
 #define FAN_FROM_REG(val, rpm_range)	((val) == 0 || (val) == 255 ? \
 				0 : (rpm_ranges[rpm_range] * 30) / (val))
 #define TEMP_LIMIT_TO_REG(val)	clamp_val((val) / 1000, 0, 255)
@@ -78,9 +83,9 @@ struct max6639_data {
 	u16 temp[2];		/* Temperature, in 1/8 C, 0..255 C */
 	bool temp_fault[2];	/* Detected temperature diode failure */
 	u8 fan[2];		/* Register value: TACH count for fans >=30 */
+	struct pwm_device	*pwmd[2]; /* max6639 has two pwm device */
 	u32 target_rpm[2];
 	u32 max_rpm[2];
-	u8 pwm[2];
 
 	u8 status;		/* Detected channel alarms and fan failures */
 
@@ -92,9 +97,10 @@ struct max6639_data {
 	/* Register values initialized only once */
 	u8 ppr[2];		/* Pulses per rotation 0..3 for 1..4 ppr */
 	u8 rpm_range[2];	/* Index in above rpm_ranges table */
-	u8 pwm_polarity[2];
 	/* Optional regulator for FAN supply */
 	struct regulator *reg;
+	/* max6639 pwm chip */
+	struct pwm_chip chip;
 };
 
 static struct max6639_data *max6639_update_device(struct device *dev)
@@ -285,8 +291,11 @@ static ssize_t pwm_show(struct device *dev, struct device_attribute *dev_attr,
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 	struct max6639_data *data = dev_get_drvdata(dev);
+	struct pwm_state state;
+
+	pwm_get_state(data->pwmd[attr->index], &state);
 
-	return sprintf(buf, "%d\n", data->pwm[attr->index] * 255 / 120);
+	return sprintf(buf, "%d\n", pwm_get_relative_duty_cycle(&state, 255));
 
 }
 
@@ -296,9 +305,9 @@ static ssize_t pwm_store(struct device *dev,
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 	struct max6639_data *data = dev_get_drvdata(dev);
-	struct i2c_client *client = data->client;
 	unsigned long val;
 	int res;
+	struct pwm_state state;
 
 	res = kstrtoul(buf, 10, &val);
 	if (res)
@@ -306,11 +315,11 @@ static ssize_t pwm_store(struct device *dev,
 
 	val = clamp_val(val, 0, 255);
 
-	mutex_lock(&data->update_lock);
-	data->pwm[attr->index] = (u8)(val * 120 / 255);
-	i2c_smbus_write_byte_data(client, MAX6639_REG_TARGTDUTY(attr->index),
-				 data->pwm[attr->index]);
-	mutex_unlock(&data->update_lock);
+	pwm_get_state(data->pwmd[attr->index], &state);
+	pwm_set_relative_duty_cycle(&state, val, 255);
+	res = pwm_apply_state(data->pwmd[attr->index], &state);
+	if (res)
+		return res;
 
 	return count;
 }
@@ -426,6 +435,7 @@ static int max6639_init_client(struct i2c_client *client,
 			       struct max6639_data *data)
 {
 	int i, err;
+	struct pwm_state state;
 
 	/* Reset chip to default values, see below for GCONFIG setup */
 	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
@@ -479,10 +489,11 @@ static int max6639_init_client(struct i2c_client *client,
 		if (err)
 			goto exit;
 
-		/* PWM 120/120 (i.e. 100%) */
-		data->pwm[i] = data->target_rpm[i];
-		err = i2c_smbus_write_byte_data(client, MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
-
+		/* Configure PWM controller */
+		pwm_get_state(data->pwmd[i], &state);
+		pwm_set_relative_duty_cycle(&state, data->target_rpm[i],
+					    data->max_rpm[i]);
+		err = pwm_apply_state(data->pwmd[i], &state);
 		if (err)
 			goto exit;
 
@@ -576,7 +587,22 @@ static int max6639_probe_child_from_dt(struct i2c_client *client,
 	else
 		data->target_rpm[i] = maxrpm;
 
-	return 0;
+	/* Get pwms property for PWM control */
+	data->pwmd[i] = devm_fwnode_pwm_get(dev, &child->fwnode, NULL);
+
+	if (!IS_ERR(data->pwmd[i]))
+		return 0;
+
+	if (PTR_ERR(data->pwmd[i]) == -EPROBE_DEFER)
+		return PTR_ERR(data->pwmd[i]);
+
+	dev_dbg(dev, "Using chip default PWM");
+	data->pwmd[i] = pwm_request_from_chip(&data->chip, i, NULL);
+	if (!IS_ERR(data->pwmd[i]))
+		return 0;
+
+	dev_dbg(dev, "Failed to configure pwm for fan %d", i);
+	return PTR_ERR_OR_ZERO(data->pwmd[i]);
 }
 
 static int max6639_probe_from_dt(struct i2c_client *client,
@@ -605,6 +631,172 @@ static int max6639_probe_from_dt(struct i2c_client *client,
 	return 0;
 }
 
+static struct max6639_data *to_max6639_pwm(struct pwm_chip *chip)
+{
+	return container_of(chip, struct max6639_data, chip);
+}
+
+static void max6639_pwm_get_state(struct pwm_chip *chip,
+				  struct pwm_device *pwm,
+				  struct pwm_state *state)
+{
+
+	struct max6639_data *data = to_max6639_pwm(chip);
+	struct i2c_client *client = data->client;
+	int value, i = pwm->hwpwm, x;
+	unsigned int freq;
+
+	mutex_lock(&data->update_lock);
+
+	value = i2c_smbus_read_byte_data(client, MAX6639_REG_FAN_CONFIG1(i));
+	if (value < 0)
+		goto abort;
+
+	if (value & MAX6639_FAN_CONFIG1_PWM) {
+		state->enabled = true;
+
+		/* Determine frequency from respective registers */
+		value = i2c_smbus_read_byte_data(client,
+						 MAX6639_REG_FAN_CONFIG3(i));
+		if (value < 0)
+			goto abort;
+		x = value & MAX6639_FAN_CONFIG3_FREQ_MASK;
+
+		value = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
+		if (value < 0)
+			goto abort;
+		if (value & MAX6639_GCONFIG_PWM_FREQ_HI)
+			x |= 0x4;
+		x &= 0x7;
+		freq = freq_table[x];
+
+		state->period = DIV_ROUND_UP(NSEC_PER_SEC, freq);
+
+		value = i2c_smbus_read_byte_data(client,
+						 MAX6639_REG_TARGTDUTY(i));
+		if (value < 0)
+			goto abort;
+		/* max6639 supports 120 slots only */
+		state->duty_cycle = mul_u64_u32_div(state->period, value, 120);
+
+		value = i2c_smbus_read_byte_data(client,
+						 MAX6639_REG_FAN_CONFIG2a(i));
+		if (value < 0)
+			goto abort;
+		value &= MAX6639_REG_FAN_CONFIG2a_PWM_POL;
+		state->polarity = (value != 0);
+	} else
+		state->enabled = false;
+
+abort:
+	mutex_unlock(&data->update_lock);
+
+}
+
+static int max6639_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			     const struct pwm_state *state)
+{
+	struct max6639_data *data = to_max6639_pwm(chip);
+	struct i2c_client *client = data->client;
+	int value = 0, i = pwm->hwpwm, x;
+	unsigned int freq;
+	struct pwm_state cstate;
+
+	cstate = pwm->state;
+
+	mutex_lock(&data->update_lock);
+
+	if (state->period != cstate.period) {
+		/* Configure frequency */
+		freq = DIV_ROUND_UP_ULL(NSEC_PER_SEC, state->period);
+		/* Chip supports limited number of frequency */
+		for (x = 0; x < sizeof(freq_table); x++)
+			if (freq <= freq_table[x])
+				break;
+
+		value = i2c_smbus_read_byte_data(client,
+						 MAX6639_REG_FAN_CONFIG3(i));
+		if (value < 0)
+			goto abort;
+		value &= ~MAX6639_FAN_CONFIG3_FREQ_MASK;
+		value |= (x & MAX6639_FAN_CONFIG3_FREQ_MASK);
+		value = i2c_smbus_write_byte_data(client,
+						  MAX6639_REG_FAN_CONFIG3(i),
+						  value);
+
+		value = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
+		if (value < 0)
+			goto abort;
+
+		if (x >> 2)
+			value &= ~MAX6639_GCONFIG_PWM_FREQ_HI;
+		else
+			value |= MAX6639_GCONFIG_PWM_FREQ_HI;
+		value = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
+						  value);
+		if (value < 0)
+			goto abort;
+	}
+
+	/* Configure dutycycle */
+	if (state->duty_cycle != cstate.duty_cycle ||
+	    state->period != cstate.period) {
+		value = DIV_ROUND_DOWN_ULL(
+				state->duty_cycle * MAX6639_REG_TARGTDUTY_SLOT,
+				state->period);
+		value = i2c_smbus_write_byte_data(client,
+						  MAX6639_REG_TARGTDUTY(i),
+						  value);
+		if (value < 0)
+			goto abort;
+	}
+
+	/* Configure polarity */
+	if (state->polarity != cstate.polarity) {
+		value = i2c_smbus_read_byte_data(client,
+						 MAX6639_REG_FAN_CONFIG2a(i));
+		if (value < 0)
+			goto abort;
+		if (state->polarity == PWM_POLARITY_NORMAL)
+			value |= MAX6639_REG_FAN_CONFIG2a_PWM_POL;
+		else
+			value &= ~MAX6639_REG_FAN_CONFIG2a_PWM_POL;
+		value = i2c_smbus_write_byte_data(client,
+						  MAX6639_REG_FAN_CONFIG2a(i),
+						  value);
+		if (value < 0)
+			goto abort;
+	}
+
+	if (state->enabled == cstate.enabled)
+		goto abort;
+
+	value = i2c_smbus_read_byte_data(client, MAX6639_REG_FAN_CONFIG1(i));
+	if (value < 0)
+		goto abort;
+	if (state->enabled)
+		value |= MAX6639_FAN_CONFIG1_PWM;
+	else
+		value &= ~MAX6639_FAN_CONFIG1_PWM;
+
+	value = i2c_smbus_write_byte_data(client, MAX6639_REG_FAN_CONFIG1(i),
+					  value);
+	if (value < 0)
+		goto abort;
+	value = 0;
+
+abort:
+	mutex_unlock(&data->update_lock);
+
+	return value;
+}
+
+static const struct pwm_ops max6639_pwm_ops = {
+	.apply = max6639_pwm_apply,
+	.get_state = max6639_pwm_get_state,
+	.owner = THIS_MODULE,
+};
+
 static int max6639_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
@@ -618,6 +810,15 @@ static int max6639_probe(struct i2c_client *client)
 
 	data->client = client;
 
+	/* Add PWM controller of max6639 */
+	data->chip.dev = dev;
+	data->chip.ops = &max6639_pwm_ops;
+	data->chip.npwm = 2;
+
+	err = devm_pwmchip_add(dev, &data->chip);
+	if (err < 0)
+		return dev_err_probe(dev, err, "failed to add PWM chip\n");
+
 	data->reg = devm_regulator_get_optional(dev, "fan");
 	if (IS_ERR(data->reg)) {
 		if (PTR_ERR(data->reg) != -ENODEV) {
-- 
2.37.3