[PATCH v5 0/5] iio: mcp9600: Features and improvements

[PATCH v5 0/5] iio: mcp9600: Features and improvements

[Ben Collins]

From: Ben Collins <bcollins@watter.com>

ChangeLog:
v5 -> v6:
  - Fix accidental typo added in dt-bindings: IRQ_TYPE_EDGE_RISIN
  - Correct some constraints in dt-bindings
  - Reverse if/then for mcp9601 vs mcp9600 constraints in dt-bindings
  - Updates to changelog for patch 2/6 (dt-bindings mcp9600)
  - Cleanup tabs that were converted to spaces
  - Split thermocouple-type default to separate patch

v4 -> v5:
  - Missed a one line fix to IIR patch (5/5)

v3 -> v4:
  - Based on feedback from David Lechner <dlechner@baylibre.com>
    * Allow fallback compatible in dt-bindings for mcp9601.
  - Based on feedback from Jonathan Cameron <jic23@kernel.org>
    * Be explicit in patch description for fixed width changes.
    * Check chip_info for NULL to quiet warnings from kernel-test-robot
    * Remove "and similar" for long description of MCP9600.
  - Based on lots of feedback, use frequency values for IIR, and use
    filter_type[none, ema] to enable or disable.
  - Set default 3 for thermocouple in dt-binding
  - Rework open/short circuit in dt-bindings

v2 -> v3:
  - Improve changelogs in each patch
  - Based on feedback from Andy Shevchenko <andy.shevchenko@gmail.com>
    * Set register offsets to fixed width
    * Fix typos
    * Future-proof Kconfig changes
    * Convert to using chip_info paradigm
    * Verbiage: dt -> firmware description
    * Use proper specifiers and drop castings
    * Fix register offset to be fixed-width
    * u8 for cfg var
    * Fix % type for u32 to be %u
    * Make blank lines consistent between case statements
    * FIELD_PREP -> FIELD_MODIFY
    * Remove explicit setting of 0 value in filter_level
  - Based on feedback from David Lechner <dlechner@baylibre.com>
    * Rework IIR values exposed to sysfs. Using the ratios, there was no
      way to represent "disabled" (i.e. infinity). Based on the bmp280
      driver I went with using the power coefficients (e.g. 1, 2, 4, 8,
      ...) where 1 is disabled (n=0).

v1 -> v2:
  - Break into individual patches

v1:
  - Initial patch to enable IIR and thermocouple-type
  - Recognize mcp9601

Ben Collins (6):
  dt-bindings: iio: mcp9600: Set default 3 for thermocouple-type
  dt-bindings: iio: mcp9600: Add microchip,mcp9601 and add constraints
  iio: mcp9600: White space and fixed width cleanup
  iio: mcp9600: Recognize chip id for mcp9601
  iio: mcp9600: Add support for thermocouple-type
  iio: mcp9600: Add support for IIR filter

 .../iio/temperature/microchip,mcp9600.yaml    |  61 +++-
 drivers/iio/temperature/Kconfig               |   8 +-
 drivers/iio/temperature/mcp9600.c             | 295 +++++++++++++++++-
 3 files changed, 341 insertions(+), 23 deletions(-)

-- 
2.39.5

[PATCH 1/6] dt-bindings: iio: mcp9600: Set default 3 for thermocouple-type

[Ben Collins]

From: Ben Collins <bcollins@watter.com>

As is already documented in this file, Type-K is the default, so make
that explicit in the dt-bindings.

Signed-off-by: Ben Collins <bcollins@watter.com>
---
 .../devicetree/bindings/iio/temperature/microchip,mcp9600.yaml   | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/iio/temperature/microchip,mcp9600.yaml b/Documentation/devicetree/bindings/iio/temperature/microchip,mcp9600.yaml
index d2cafa38a544..57b387a1accc 100644
--- a/Documentation/devicetree/bindings/iio/temperature/microchip,mcp9600.yaml
+++ b/Documentation/devicetree/bindings/iio/temperature/microchip,mcp9600.yaml
@@ -37,6 +37,7 @@ properties:
 
   thermocouple-type:
     $ref: /schemas/types.yaml#/definitions/uint32
+    default: 3
     description:
       Type of thermocouple (THERMOCOUPLE_TYPE_K if omitted).
       Use defines in dt-bindings/iio/temperature/thermocouple.h.
-- 
2.39.5

Re: [PATCH 1/6] dt-bindings: iio: mcp9600: Set default 3 for thermocouple-type

[Krzysztof Kozlowski]

On Mon, Aug 18, 2025 at 02:32:09PM -0400, Ben Collins wrote:
> From: Ben Collins <bcollins@watter.com>
> 
> As is already documented in this file, Type-K is the default, so make
> that explicit in the dt-bindings.
> 
> Signed-off-by: Ben Collins <bcollins@watter.com>
> ---
>  .../devicetree/bindings/iio/temperature/microchip,mcp9600.yaml   | 1 +
>  1 file changed, 1 insertion(+)

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

[PATCH 2/6] dt-bindings: iio: mcp9600: Add microchip,mcp9601 and add constraints

[Ben Collins]

From: Ben Collins <bcollins@watter.com>

Add microchip,mcp9601 compatible in addition to the original
microchip,mcp9600 to designate support between these two chips.

The current dt-binding has open-circuit and short-circuit as interrupt
names, but these are only supported in mcp9601.

The OC and SC detection requires that mcp9601 VSENSE be wired up, which
not only enables the OC SC interrupts, but also the OC and SC status
register bits.

Add a microchip,vsense boolean to show the chip is wired for this
support.

Add constraints so this feature only applies if the mcp9601 compatible
is selected.

Signed-off-by: Ben Collins <bcollins@watter.com>
---
 .../iio/temperature/microchip,mcp9600.yaml    | 60 ++++++++++++++++++-
 1 file changed, 57 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/iio/temperature/microchip,mcp9600.yaml b/Documentation/devicetree/bindings/iio/temperature/microchip,mcp9600.yaml
index 57b387a1accc..c22edb4ab852 100644
--- a/Documentation/devicetree/bindings/iio/temperature/microchip,mcp9600.yaml
+++ b/Documentation/devicetree/bindings/iio/temperature/microchip,mcp9600.yaml
@@ -4,7 +4,7 @@
 $id: http://devicetree.org/schemas/iio/temperature/microchip,mcp9600.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: Microchip MCP9600 thermocouple EMF converter
+title: Microchip MCP9600 and similar thermocouple EMF converters
 
 maintainers:
   - Andrew Hepp <andrew.hepp@ahepp.dev>
@@ -14,7 +14,11 @@ description:
 
 properties:
   compatible:
-    const: microchip,mcp9600
+    oneOf:
+      - const: microchip,mcp9600
+      - items:
+          - const: microchip,mcp9601
+          - const: microchip,mcp9600
 
   reg:
     maxItems: 1
@@ -34,6 +38,8 @@ properties:
         - alert2
         - alert3
         - alert4
+        - open-circuit
+        - short-circuit
 
   thermocouple-type:
     $ref: /schemas/types.yaml#/definitions/uint32
@@ -43,8 +49,37 @@ properties:
       Use defines in dt-bindings/iio/temperature/thermocouple.h.
       Supported types are B, E, J, K, N, R, S, T.
 
+  microchip,vsense:
+    type: boolean
+    description:
+      This flag indicates that the chip has been wired with VSENSE to
+      enable open and short circuit detect.
+
   vdd-supply: true
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          not:
+            contains:
+              const: microchip,mcp9601
+    then:
+      properties:
+        interrupts:
+          minItems: 1
+          maxItems: 4
+        interrupt-names:
+          minItems: 1
+          maxItems: 4
+          items:
+            enum:
+              - alert1
+              - alert2
+              - alert3
+              - alert4
+        microchip,vsense: false
+
 required:
   - compatible
   - reg
@@ -64,8 +99,27 @@ examples:
             reg = <0x60>;
             interrupt-parent = <&gpio>;
             interrupts = <25 IRQ_TYPE_EDGE_RISING>;
-            interrupt-names = "open-circuit";
+            interrupt-names = "alert1";
             thermocouple-type = <THERMOCOUPLE_TYPE_K>;
             vdd-supply = <&vdd>;
         };
     };
+  - |
+    #include <dt-bindings/iio/temperature/thermocouple.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        temperature-sensor@62 {
+            compatible = "microchip,mcp9601",
+                         "microchip,mcp9600";
+            microchip,vsense;
+            reg = <0x62>;
+            interrupt-parent = <&gpio>;
+            interrupts = <22 IRQ_TYPE_EDGE_RISING
+                          23 IRQ_TYPE_EDGE_RISING>;
+            interrupt-names = "open-circuit", "short-circuit";
+            vdd-supply = <&vdd>;
+        };
+    };
-- 
2.39.5

Re: [PATCH 2/6] dt-bindings: iio: mcp9600: Add microchip,mcp9601 and add constraints

[Rob Herring (Arm)]

On Mon, 18 Aug 2025 14:32:10 -0400, Ben Collins wrote:
> From: Ben Collins <bcollins@watter.com>
> 
> Add microchip,mcp9601 compatible in addition to the original
> microchip,mcp9600 to designate support between these two chips.
> 
> The current dt-binding has open-circuit and short-circuit as interrupt
> names, but these are only supported in mcp9601.
> 
> The OC and SC detection requires that mcp9601 VSENSE be wired up, which
> not only enables the OC SC interrupts, but also the OC and SC status
> register bits.
> 
> Add a microchip,vsense boolean to show the chip is wired for this
> support.
> 
> Add constraints so this feature only applies if the mcp9601 compatible
> is selected.
> 
> Signed-off-by: Ben Collins <bcollins@watter.com>
> ---
>  .../iio/temperature/microchip,mcp9600.yaml    | 60 ++++++++++++++++++-
>  1 file changed, 57 insertions(+), 3 deletions(-)
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/iio/temperature/microchip,mcp9600.yaml: properties:interrupt-names:items:enum: ['open-circuit', 'short-circuit', 'alert1', 'alert2', 'alert3', 'alert4', 'open-circuit', 'short-circuit'] has non-unique elements
	hint: "enum" must be an array of either integers or strings
	from schema $id: http://devicetree.org/meta-schemas/keywords.yaml#

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20250818183214.380847-3-bcollins@kernel.org

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.

Re: [PATCH 2/6] dt-bindings: iio: mcp9600: Add microchip,mcp9601 and add constraints

[Krzysztof Kozlowski]

On Mon, Aug 18, 2025 at 02:32:10PM -0400, Ben Collins wrote:
>  properties:
>    compatible:
> -    const: microchip,mcp9600
> +    oneOf:
> +      - const: microchip,mcp9600
> +      - items:
> +          - const: microchip,mcp9601
> +          - const: microchip,mcp9600
>  
>    reg:
>      maxItems: 1
> @@ -34,6 +38,8 @@ properties:
>          - alert2
>          - alert3
>          - alert4
> +        - open-circuit
> +        - short-circuit

I do not understand this change. And again, if you tested it before
sending, you should see error.

Best regards,
Krzysztof

Re: [PATCH v5 0/5] iio: mcp9600: Features and improvements

[Krzysztof Kozlowski]

On Mon, Aug 18, 2025 at 02:32:08PM -0400, Ben Collins wrote:
> From: Ben Collins <bcollins@watter.com>
> 
> ChangeLog:
> v5 -> v6:
>   - Fix accidental typo added in dt-bindings: IRQ_TYPE_EDGE_RISIN
>   - Correct some constraints in dt-bindings
>   - Reverse if/then for mcp9601 vs mcp9600 constraints in dt-bindings
>   - Updates to changelog for patch 2/6 (dt-bindings mcp9600)
>   - Cleanup tabs that were converted to spaces
>   - Split thermocouple-type default to separate patch

Please start using b4, so you will get changelogs with lore links for
free and ALL your patches will be properly versioned. git can do that
as well - git format-patch -v5 --cover-letter, if you don't want to use
b4.

Best regards,
Krzysztof

Re: [PATCH v5 0/5] iio: mcp9600: Features and improvements

[Jonathan Cameron]

On Tue, 19 Aug 2025 08:55:44 +0200
Krzysztof Kozlowski <krzk@kernel.org> wrote:

> On Mon, Aug 18, 2025 at 02:32:08PM -0400, Ben Collins wrote:
> > From: Ben Collins <bcollins@watter.com>
> > 
> > ChangeLog:
> > v5 -> v6:
> >   - Fix accidental typo added in dt-bindings: IRQ_TYPE_EDGE_RISIN
> >   - Correct some constraints in dt-bindings
> >   - Reverse if/then for mcp9601 vs mcp9600 constraints in dt-bindings
> >   - Updates to changelog for patch 2/6 (dt-bindings mcp9600)
> >   - Cleanup tabs that were converted to spaces
> >   - Split thermocouple-type default to separate patch  
> 
> Please start using b4, so you will get changelogs with lore links for
> free and ALL your patches will be properly versioned. git can do that
> as well - git format-patch -v5 --cover-letter, if you don't want to use
> b4.

Second that.  This is what it looks like in patchwork that I use
for managing reviews / merges etc.
https://patchwork.kernel.org/project/linux-iio/list/?series=992678

version number not easy to find as it gets dropped from the series title
and is only normally listed for the patches. 

> 
> Best regards,
> Krzysztof
> 

Re: [PATCH v5 0/5] iio: mcp9600: Features and improvements

[Ben Collins]

On Tue, Aug 19, 2025 at 07:24:55PM -0500, Jonathan Cameron wrote:
> On Tue, 19 Aug 2025 08:55:44 +0200
> Krzysztof Kozlowski <krzk@kernel.org> wrote:
> 
> > On Mon, Aug 18, 2025 at 02:32:08PM -0400, Ben Collins wrote:
> > > From: Ben Collins <bcollins@watter.com>
> > > 
> > > ChangeLog:
> > > v5 -> v6:
> > >   - Fix accidental typo added in dt-bindings: IRQ_TYPE_EDGE_RISIN
> > >   - Correct some constraints in dt-bindings
> > >   - Reverse if/then for mcp9601 vs mcp9600 constraints in dt-bindings
> > >   - Updates to changelog for patch 2/6 (dt-bindings mcp9600)
> > >   - Cleanup tabs that were converted to spaces
> > >   - Split thermocouple-type default to separate patch  
> > 
> > Please start using b4, so you will get changelogs with lore links for
> > free and ALL your patches will be properly versioned. git can do that
> > as well - git format-patch -v5 --cover-letter, if you don't want to use
> > b4.
> 
> Second that.  This is what it looks like in patchwork that I use
> for managing reviews / merges etc.
> https://patchwork.kernel.org/project/linux-iio/list/?series=992678
> 
> version number not easy to find as it gets dropped from the series title
> and is only normally listed for the patches. 

I appreciate both of you suggesting this. I've switched to b4 now and
now I don't know how anyone could not use it.

-- 
 Ben Collins
 https://libjwt.io
 https://github.com/benmcollins
 --
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