Re: [PATCH 2/3] dt-bindings: iio: temperature: ltc2983: support more parts

[Cosmin Tanislav <demonsingur@gmail.com>]

On 10/14/22 18:37, Jonathan Cameron wrote:
> On Fri, 14 Oct 2022 15:37:23 +0300
> Cosmin Tanislav <demonsingur@gmail.com> wrote:
> 
>> From: Cosmin Tanislav <cosmin.tanislav@analog.com>
>>
>> Add support for the following parts:
>>   * LTC2984
>>   * LTC2986
>>   * LTM2985
>>
>> The LTC2984 is a variant of the LTC2983 with EEPROM.
>> The LTC2986 is a variant of the LTC2983 with only 10 channels,
>> EEPROM and support for active analog temperature sensors.
> 
> If they 'work' but with fewer features, perhaps a fallback
> compatible?
> 

10 channels vs 20 channels. Using ltc2983 compatible as fallback
would allow you to have 10 non-functional channels specified in the
dts.

>> The LTM2985 is software-compatible with the LTC2986.
> 
> Fallback compatible?
> 
>>
>> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
>> ---
>>   .../bindings/iio/temperature/adi,ltc2983.yaml | 63 +++++++++++++++++--
>>   1 file changed, 59 insertions(+), 4 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
>> index 722781aa4697..c33ab524fb64 100644
>> --- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
>> +++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
>> @@ -4,19 +4,27 @@
>>   $id: http://devicetree.org/schemas/iio/temperature/adi,ltc2983.yaml#
>>   $schema: http://devicetree.org/meta-schemas/core.yaml#
>>   
>> -title: Analog Devices LTC2983 Multi-sensor Temperature system
>> +title: Analog Devices LTC2983, LTC2986, LTM2985 Multi-sensor Temperature system
>>   
>>   maintainers:
>>     - Nuno Sá <nuno.sa@analog.com>
>>   
>>   description: |
>> -  Analog Devices LTC2983 Multi-Sensor Digital Temperature Measurement System
>> +  Analog Devices LTC2983, LTC2984, LTC2986, LTM2985 Multi-Sensor Digital
>> +  Temperature Measurement Systems
>> +
>>     https://www.analog.com/media/en/technical-documentation/data-sheets/2983fc.pdf
>> +  https://www.analog.com/media/en/technical-documentation/data-sheets/2984fb.pdf
>> +  https://www.analog.com/media/en/technical-documentation/data-sheets/29861fa.pdf
>> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ltm2985.pdf
>>   
>>   properties:
>>     compatible:
>>       enum:
>>         - adi,ltc2983
>> +      - adi,ltc2984
>> +      - adi,ltc2986
>> +      - adi,ltm2985
>>   
>>     reg:
>>       maxItems: 1
>> @@ -26,7 +34,7 @@ properties:
>>   
>>     adi,mux-delay-config-us:
>>       description:
>> -      The LTC2983 performs 2 or 3 internal conversion cycles per temperature
>> +      The device performs 2 or 3 internal conversion cycles per temperature
> 
> Definitely a lesson here in avoiding device names in the descriptions!
> 
>>         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
>> @@ -145,7 +153,7 @@ patternProperties:
>>         adi,three-conversion-cycles:
>>           description:
>>             Boolean property which set's three conversion cycles removing
>> -          parasitic resistance effects between the LTC2983 and the diode.
>> +          parasitic resistance effects between the device and the diode.
>>           type: boolean
>>   
>>         adi,average-on:
>> @@ -353,6 +361,41 @@ patternProperties:
>>           description: Boolean property which set's the adc as single-ended.
>>           type: boolean
>>   
>> +  "^temp@":
>> +    type: object
>> +    description:
>> +      Represents a channel which is being used as an active analog temperature
>> +      sensor.
>> +
>> +    properties:
>> +      adi,sensor-type:
>> +        description:
>> +          Identifies the sensor as an active analog temperature sensor.
>> +        $ref: /schemas/types.yaml#/definitions/uint32
>> +        const: 31
> 
> Ah. This is a bit odd as it's fixed for the channel type.  However there
> is precedence in this binding so fair enough.
> 

I think it

>> +
>> +      adi,single-ended:
>> +        description: Boolean property which sets the sensor as single-ended.
>> +        type: boolean
>> +
>> +      adi,custom-temp:
>> +        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 71 and 72.
>> +          Note should be signed, but dtc doesn't currently maintain the
>> +          sign.
>> +        $ref: /schemas/types.yaml#/definitions/uint64-matrix
>> +        minItems: 3
>> +        maxItems: 64
>> +        items:
>> +          minItems: 2
>> +          maxItems: 2
>> +
>> +    required:
>> +      - adi,custom-temp
>> +
>>     "^rsense@":
>>       type: object
>>       description:
>> @@ -382,6 +425,18 @@ required:
>>     - reg
>>     - interrupts
>>   
>> +allOf:
>> +  - if:
>> +      properties:
>> +        compatible:
>> +          contains:
>> +            enum:
>> +              - adi,ltc2983
>> +              - adi,ltc2984
>> +    then:
>> +      patternProperties:
>> +        "^temp@": false
>> +
>>   additionalProperties: false
>>   
>>   examples:
>