Re: [PATCH v3 2/4] dt-bindings: iio: temperature: ltc2983: refine

[Rob Herring <robh@kernel.org>]

On Tue, Oct 25, 2022 at 11:18:40AM +0300, Cosmin Tanislav wrote:
> From: Cosmin Tanislav <cosmin.tanislav@analog.com>

'refine' is not a great subject. That's due to doing many things in 1 
patch. I'd at least split out all the 'description' changes from actual 
schema changes to separate patches.

> 
>  * make sure addresses are represented as hex
>  * add note about wrong unit value for adi,mux-delay-config-us
>  * simplify descriptions
>  * add descriptions for the items of custom sensor tables
>  * add default property values where applicable
>  * use conditionals to extend minimum reg value
>    for single ended sensors
>  * remove " around phandle schema $ref
>  * remove label from example and use generic temperature
>    sensor name
> 
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> ---
>  .../bindings/iio/temperature/adi,ltc2983.yaml | 270 ++++++++++--------
>  1 file changed, 144 insertions(+), 126 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> index 722781aa4697..a878fd84636f 100644
> --- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> +++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> @@ -26,25 +26,25 @@ properties:
>  
>    adi,mux-delay-config-us:
>      description:
> -      The LTC2983 performs 2 or 3 internal conversion cycles per temperature
> -      result. Each conversion cycle is performed with different excitation and
> -      input multiplexer configurations. Prior to each conversion, these
> -      excitation circuits and input switch configurations are changed and an
> -      internal 1ms delay ensures settling prior to the conversion cycle in most
> -      cases. An extra delay can be configured using this property. The value is
> -      rounded to nearest 100us.
> +      Extra delay prior to each conversion, in addition to the internal 1ms
> +      delay, for the multiplexer to switch input configurations and
> +      excitation values.
> +
> +      This property is supposed to be in microseconds, but to maintain
> +      compatibility, this value will be multiplied by 100 before usage.

You need '|' for the block if you want to retain formatting.

>      maximum: 255
> +    default: 0
>  
>    adi,filter-notch-freq:
>      description:
> -      Set's the default setting of the digital filter. The default is
> -      simultaneous 50/60Hz rejection.
> +      Notch frequency of the digital filter.
>        0 - 50/60Hz rejection
>        1 - 60Hz rejection
>        2 - 50Hz rejection
>      $ref: /schemas/types.yaml#/definitions/uint32
>      minimum: 0
>      maximum: 2
> +    default: 0
>  
>    '#address-cells':
>      const: 1
> @@ -53,19 +53,19 @@ properties:
>      const: 0
>  
>  patternProperties:
> -  "@([1-9]|1[0-9]|20)$":
> +  "@([0-9a-f]+)$":

Before 1-20 was supported which matched 'reg' and now there is no limit. 
However, you did fix that the unit address should be hex. So it should 
be:

"@([1-9a-f]|1[0-4])$"

>      type: object
> -
> +    description: Sensor.
>      properties:
>        reg:
>          description:
> -          The channel number. It can be connected to one of the 20 channels of
> -          the device.
> +          Channel number. Connects the sensor to the channel with this number
> +          of the device.
>          minimum: 1
>          maximum: 20
>  
>        adi,sensor-type:
> -        description: Identifies the type of sensor connected to the device.
> +        description: Type of sensor connected to the device.
>          $ref: /schemas/types.yaml#/definitions/uint32
>  
>      required:
> @@ -74,10 +74,7 @@ patternProperties:
>  
>    "^thermocouple@":
>      type: object
> -    description:
> -      Represents a thermocouple sensor which is connected to one of the device
> -      channels.
> -

Keep the blank line.

> +    description: Thermocouple sensor.
>      properties:
>        adi,sensor-type:
>          description: |
> @@ -95,87 +92,86 @@ patternProperties:
>          maximum: 9
>  
>        adi,single-ended:
> -        description:
> -          Boolean property which set's the thermocouple as single-ended.
> +        description: Whether the sensor is single-ended.
>          type: boolean
>  
>        adi,sensor-oc-current-microamp:
> -        description:
> -          This property set's the pulsed current value applied during
> -          open-circuit detect.
> +        description: Pulsed current value applied during open-circuit detect.
>          enum: [10, 100, 500, 1000]
> +        default: 10
>  
>        adi,cold-junction-handle:
>          description:
> -          Phandle which points to a sensor object responsible for measuring
> -          the thermocouple cold junction temperature.
> -        $ref: "/schemas/types.yaml#/definitions/phandle"
> +          Sensor responsible for measuring the thermocouple cold junction
> +          temperature.
> +        $ref: /schemas/types.yaml#/definitions/phandle
>  
>        adi,custom-thermocouple:
>          description:
> -          This is a table, where each entry should be a pair of
> -          voltage(mv)-temperature(K). The entries must be given in nv and uK
> -          so that, the original values must be multiplied by 1000000. For
> -          more details look at table 69 and 70.
> -          Note should be signed, but dtc doesn't currently maintain the
> -          sign.
> +          Used for digitizing custom thermocouples.
> +          See Page 59 of the datasheet.
>          $ref: /schemas/types.yaml#/definitions/uint64-matrix
>          minItems: 3
>          maxItems: 64
>          items:
> -          minItems: 2
> -          maxItems: 2
> +          items:
> +            - description: Voltage point in nV, signed.
> +            - description: Temperature point in uK.
> +
> +    allOf:
> +      - if:
> +          properties:
> +            adi,sensor-type:
> +              const: 9
> +        then:
> +          required:
> +            - adi,custom-thermocouple
>  
>    "^diode@":
>      type: object
> -    description:
> -      Represents a diode sensor which is connected to one of the device
> -      channels.
> -
> +    description: Diode sensor.
>      properties:
>        adi,sensor-type:
> -        description: Identifies the sensor as a diode.
> +        description: Sensor type for diodes.
>          $ref: /schemas/types.yaml#/definitions/uint32
>          const: 28
>  
>        adi,single-ended:
> -        description: Boolean property which set's the diode as single-ended.
> +        description: Whether the sensor is single-ended.
>          type: boolean
>  
>        adi,three-conversion-cycles:
>          description:
> -          Boolean property which set's three conversion cycles removing
> -          parasitic resistance effects between the LTC2983 and the diode.
> +          Whether to use three conversion cycles to remove parasitic
> +          resistance between the device and the diode.
>          type: boolean
>  
>        adi,average-on:
>          description:
> -          Boolean property which enables a running average of the diode
> -          temperature reading. This reduces the noise when the diode is used
> -          as a cold junction temperature element on an isothermal block
> -          where temperatures change slowly.
> +          Whether to use a running average of the diode temperature
> +          reading to reduce the noise when the diode is used as a cold
> +          junction temperature element on an isothermal block where
> +          temperatures change slowly.
>          type: boolean
>  
>        adi,excitation-current-microamp:
>          description:
> -          This property controls the magnitude of the excitation current
> -          applied to the diode. Depending on the number of conversions
> -          cycles, this property will assume different predefined values on
> -          each cycle. Just set the value of the first cycle (1l).
> +          Magnitude of the 1l excitation current applied to the diode.
> +          4l excitation current will be 4 times this value, and 8l
> +          excitation current will be 8 times value.
>          enum: [10, 20, 40, 80]
> +        default: 10
>  
>        adi,ideal-factor-value:
>          description:
> -          This property sets the diode ideality factor. The real value must
> -          be multiplied by 1000000 to remove the fractional part. For more
> -          information look at table 20 of the datasheet.
> +          Diode ideality factor.
> +          Set this property to 1000000 times the real value.
>          $ref: /schemas/types.yaml#/definitions/uint32
> +        default: 0
>  
>    "^rtd@":
>      type: object
> -    description:
> -      Represents a rtd sensor which is connected to one of the device channels.
> -
> +    description: RTD sensor.

Keep the blank line. And any other case.

>      properties:
>        reg:
>          minimum: 2
> @@ -197,56 +193,57 @@ patternProperties:
>          maximum: 18
>  
>        adi,rsense-handle:
> -        description:
> -          Phandle pointing to a rsense object associated with this RTD.
> -        $ref: "/schemas/types.yaml#/definitions/phandle"
> +        description: Associated sense resistor sensor.
> +        $ref: /schemas/types.yaml#/definitions/phandle
>  
>        adi,number-of-wires:
>          description:
> -          Identifies the number of wires used by the RTD. Setting this
> -          property to 5 means 4 wires with Kelvin Rsense.
> +          Number of wires used by the RTD.
> +          5 means 4 wires with Kelvin sense resistor.
>          $ref: /schemas/types.yaml#/definitions/uint32
>          enum: [2, 3, 4, 5]
> +        default: 2
>  
>        adi,rsense-share:
>          description:
> -          Boolean property which enables Rsense sharing, where one sense
> -          resistor is used for multiple 2-, 3-, and/or 4-wire RTDs.
> +          Whether to enable sense resistor sharing, where one sense
> +          resistor is used by multiple sensors.
>          type: boolean
>  
>        adi,current-rotate:
>          description:
> -          Boolean property which enables excitation current rotation to
> -          automatically remove parasitic thermocouple effects. Note that
> -          this property is not allowed for 2- and 3-wire RTDs.
> +          Whether to enable excitation current rotation to automatically
> +          remove parasitic thermocouple effects.
>          type: boolean
>  
>        adi,excitation-current-microamp:
> -        description:
> -          This property controls the magnitude of the excitation current
> -          applied to the RTD.
> +        description: Excitation current applied to the RTD.
>          enum: [5, 10, 25, 50, 100, 250, 500, 1000]
> +        default: 5
>  
>        adi,rtd-curve:
>          description:
> -          This property set the RTD curve used and the corresponding
> -          Callendar-VanDusen constants. Look at table 30 of the datasheet.
> +          RTD curve and the corresponding Callendar-VanDusen constants.
> +          0 - European
> +          1 - American
> +          2 - Japanese
> +          3 - ITS-90
>          $ref: /schemas/types.yaml#/definitions/uint32
>          minimum: 0
>          maximum: 3
> +        default: 0
>  
>        adi,custom-rtd:
>          description:
> -          This is a table, where each entry should be a pair of
> -          resistance(ohm)-temperature(K). The entries added here are in uohm
> -          and uK. For more details values look at table 74 and 75.
> +          Used for digitizing custom RTDs.
> +          See Page 62 of the datasheet.
>          $ref: /schemas/types.yaml#/definitions/uint64-matrix
> +        minItems: 3
> +        maxItems: 64
>          items:
> -          minItems: 3
> -          maxItems: 64
>            items:
> -            minItems: 2
> -            maxItems: 2
> +            - description: Resistance point in uOhms.
> +            - description: Temperature point in uK.
>  
>      required:
>        - adi,rsense-handle
> @@ -254,12 +251,25 @@ patternProperties:
>      dependencies:
>        adi,current-rotate: [ "adi,rsense-share" ]
>  
> +    allOf:
> +      - if:
> +          properties:
> +            adi,number-of-wires:
> +              enum: [2, 3]

This is also true if adi,number-of-wires is not present. You need 
'required' if that's not ensured already. (Unless this was intentional)

> +        then:
> +          properties:
> +            adi,current-rotate: false
> +      - if:
> +          properties:
> +            adi,sensor-type:
> +              const: 18
> +        then:
> +          required:
> +            - adi,custom-rtd
> +
>    "^thermistor@":
>      type: object
> -    description:
> -      Represents a thermistor sensor which is connected to one of the device
> -      channels.
> -
> +    description: Thermistor sensor.
>      properties:
>        adi,sensor-type:
>          description:
> @@ -277,61 +287,53 @@ patternProperties:
>          maximum: 27
>  
>        adi,rsense-handle:
> -        description:
> -          Phandle pointing to a rsense object associated with this
> -          thermistor.
> -        $ref: "/schemas/types.yaml#/definitions/phandle"
> +        description: Associated sense resistor sensor.
> +        $ref: /schemas/types.yaml#/definitions/phandle
>  
>        adi,single-ended:
> -        description:
> -          Boolean property which set's the thermistor as single-ended.
> +        description: Whether the sensor is single-ended.
>          type: boolean
>  
>        adi,rsense-share:
>          description:
> -          Boolean property which enables Rsense sharing, where one sense
> -          resistor is used for multiple thermistors. Note that this property
> -          is ignored if adi,single-ended is set.
> +          Whether to enable sense resistor sharing, where one sense
> +          resistor is used by multiple sensors.
>          type: boolean
>  
>        adi,current-rotate:
>          description:
> -          Boolean property which enables excitation current rotation to
> -          automatically remove parasitic thermocouple effects.
> +          Whether to enable excitation current rotation to automatically
> +          remove parasitic thermocouple effects.
>          type: boolean
>  
>        adi,excitation-current-nanoamp:
>          description:
> -          This property controls the magnitude of the excitation current
> -          applied to the thermistor. Value 0 set's the sensor in auto-range
> -          mode.
> +          Excitation current applied to the thermistor.
> +          0 sets the sensor in auto-range mode.
>          $ref: /schemas/types.yaml#/definitions/uint32
>          enum: [0, 250, 500, 1000, 5000, 10000, 25000, 50000, 100000, 250000,
>                 500000, 1000000]
> +        default: 0
> +
> +      adi,custom-steinhart:
> +        description:
> +          Steinhart-Hart coefficients in raw format, used for digitizing
> +          custom thermistors.
> +          See Page 68 of the datasheet.
> +        $ref: /schemas/types.yaml#/definitions/uint32-array
> +        maxItems: 6
>  
>        adi,custom-thermistor:
>          description:
> -          This is a table, where each entry should be a pair of
> -          resistance(ohm)-temperature(K). The entries added here are in uohm
> -          and uK only for custom thermistors. For more details look at table
> -          78 and 79.
> +          Used for digitizing custom thermistors.
> +          See Page 65 of the datasheet.
>          $ref: /schemas/types.yaml#/definitions/uint64-matrix
>          minItems: 3
>          maxItems: 64
>          items:
> -          minItems: 2
> -          maxItems: 2
> -
> -      adi,custom-steinhart:
> -        description:
> -          Steinhart-Hart coefficients are also supported and can
> -          be programmed into the device memory using this property. For
> -          Steinhart sensors the coefficients are given in the raw
> -          format. Look at table 82 for more information.
> -        $ref: /schemas/types.yaml#/definitions/uint32-array
> -        items:
> -          minItems: 6
> -          maxItems: 6
> +          items:
> +            - description: Resistance point in uOhms.
> +            - description: Temperature point in uK.
>  
>      required:
>        - adi,rsense-handle
> @@ -339,40 +341,56 @@ patternProperties:
>      dependencies:
>        adi,current-rotate: [ "adi,rsense-share" ]
>  
> +    allOf:
> +      - if:
> +          properties:
> +            adi,sensor-type:
> +              const: 26
> +        then:
> +          properties:
> +            adi,excitation-current-nanoamp:
> +              default: 1000
> +          required:
> +            - adi,custom-steinhart
> +      - if:
> +          properties:
> +            adi,sensor-type:
> +              const: 27
> +        then:
> +          properties:
> +            adi,excitation-current-nanoamp:
> +              default: 1000
> +          required:
> +            - adi,custom-thermistor
> +
>    "^adc@":
>      type: object
> -    description: Represents a channel which is being used as a direct adc.
> -
> +    description: Direct ADC sensor.
>      properties:
>        adi,sensor-type:
> -        description: Identifies the sensor as a direct adc.
> +        description: Sensor type for direct ADC sensors.
>          $ref: /schemas/types.yaml#/definitions/uint32
>          const: 30
>  
>        adi,single-ended:
> -        description: Boolean property which set's the adc as single-ended.
> +        description: Whether the sensor is single-ended.
>          type: boolean
>  
>    "^rsense@":
>      type: object
> -    description:
> -      Represents a rsense which is connected to one of the device channels.
> -      Rsense are used by thermistors and RTD's.
> -
> +    description: Sense resistor sensor.
>      properties:
>        reg:
>          minimum: 2
>          maximum: 20
>  
>        adi,sensor-type:
> -        description: Identifies the sensor as a rsense.
> +        description: Sensor type sense resistor sensors.
>          $ref: /schemas/types.yaml#/definitions/uint32
>          const: 29
>  
>        adi,rsense-val-milli-ohms:
> -        description:
> -          Sets the value of the sense resistor. Look at table 20 of the
> -          datasheet for information.
> +        description: Value of the sense resistor.
>  
>      required:
>        - adi,rsense-val-milli-ohms
> @@ -391,7 +409,7 @@ examples:
>          #address-cells = <1>;
>          #size-cells = <0>;
>  
> -        sensor_ltc2983: ltc2983@0 {
> +        temp@0 {
>                  compatible = "adi,ltc2983";
>                  reg = <0>;
>  
> -- 
> 2.38.1
> 
>