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

Jonathan Cameron
2022-10-17T10:37:54Z

On Mon, 17 Oct 2022 11:26:56 +0100
Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote:

> On Mon, 17 Oct 2022 09:53:40 +0300
> Cosmin Tanislav <demonsingur@gmail.com> wrote:
>
> > On 10/17/22 04:59, Krzysztof Kozlowski wrote:
> > > On 14/10/2022 08:37, Cosmin Tanislav 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.
> > >> The LTM2985 is software-compatible with the LTC2986.
> > >>
> > >> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
>
> Cosmin,
>
> Please take care to keep things polite. Krzysztof is reviewing an
> enormous number of bindings and is very helpful indeed. We should
> respect his feedback and respond appropriately. Sometimes what is
> 'obvious' to one person may need a clarifying comment or explanation
> for another.

Note I should have said we should respect ALL reviewers for taking
the time to look at our code. Not just the particularly active ones!

Jonathan

>
> Jonathan
>
>
> > >> ---
> > >> .../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
> > >> 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@":
> > >
> > > There is already a property for thermocouple. Isn't a thermocouple a
> > > temperature sensor? IOW, why new property is needed?
> > >
> > This node is needed for active analog temperature sensors.
> > It has fewer options than the thermocouple, as it only supports
> > a table to map from voltage to temperature and specifying whether
> > the measurement is differential or single-ended.
> >
> > If you did as much as glimpsed at the datasheet you would have
> > understood.
> >
> > >> + 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
> > >> +
> > >> + adi,single-ended:
> > >> + description: Boolean property which sets the sensor as single-ended.
> > >
> > > Drop "Boolean property which sets" - it's obvious from the type.
> > >
> >
> > That's how the rest of the file is written.
> >
> > >
> > >
> > >> + type: boolean
> > >> +
> > >> + adi,custom-temp:
> > >> + description:
> > >> + This is a table, where each entry should be a pair of
> > >
> > > "This is a table" - obvious from the type.
> > >
> >
> > That's how the rest of the file is written.
> >
> > >> + voltage(mv)-temperature(K). The entries must be given in nv and uK
> > >
> > > mv-K or nv-uK? Confusing...
> >
> > That's how the rest of the file is written.
> >
> > The chip uses mv-K, but the binding specifies nv-uK, the driver
> > translates it into the appropriate unit.
> >
> > >
> > >> + so that, the original values must be multiplied by 1000000. For
> > >> + more details look at table 71 and 72.
> > >
> > > There is no table 71 in the bindings... It seems you pasted it from
> > > somewhere.
> > >
> >
> > It's pretty obvious that "Table" in a binding refers to the datasheet.
> > But if you meant datasheet, not binding, you're looking at the wrong
> > datasheet then.
> > Also, that's how the rest of the file is written.
> >
> > >> + Note should be signed, but dtc doesn't currently maintain the
> > >> + sign.
> > >
> > > What do you mean? "Maintain" as allow or keep when building FDT? What's
> > > the problem of using negative numbers here and why it should be part of
> > > bindings?
> > >
> >
> > You're really clueless, I'll let you figure it out on your own.
> > Also, that's how the rest of the file is written.
>
> >
> > >> + $ref: /schemas/types.yaml#/definitions/uint64-matrix
> > >> + minItems: 3
> > >> + maxItems: 64
> > >> + items:
> > >> + minItems: 2
> > >> + maxItems: 2
> > >
> > > Instead describe the items with "description" (and maybe constraints)
> > > like here:
> > >
> > > https://elixir.bootlin.com/linux/v5.19/source/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.yaml#L278
> > >
> >
> > That's how the rest of the file is written.
> > If you really want to use something different, you can submit a
> > patch later and fix the whole binding however you want.
> >
> > >> +
> > >> + 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:
> > >
> > > Best regards,
> > > Krzysztof
> > >
>
>