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

Jonathan Cameron
2022-10-17T10:22:26Z

On Mon, 17 Oct 2022 10:01:03 +0300
Cosmin Tanislav <demonsingur@gmail.com> wrote:

> 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.

Ah. That one probably doesn't make sense then. The 2984?

>
> >> 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:
> >