Re: [PATCH v3 4/5] dt-bindings: iio: dac: Add adi,ltc2672.yaml

From: David Lechner
Date: Mon Jun 03 2024 - 16:17:43 EST


On 6/3/24 2:59 PM, David Lechner wrote:
> On 6/2/24 8:21 PM, Kim Seer Paller wrote:
>> Add documentation for ltc2672.
>>
>> Reported-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
>> Closes: https://lore.kernel.org/all/171643825573.1037396.2749703571529285460.robh@xxxxxxxxxx/
>> Co-developed-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
>> Signed-off-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
>> Signed-off-by: Kim Seer Paller <kimseer.paller@xxxxxxxxxx>
>> ---
>> .../bindings/iio/dac/adi,ltc2672.yaml | 158 ++++++++++++++++++
>> MAINTAINERS | 1 +
>> 2 files changed, 159 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/iio/dac/adi,ltc2672.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ltc2672.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ltc2672.yaml
>> new file mode 100644
>> index 000000000000..d143a9db7010
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/iio/dac/adi,ltc2672.yaml
>> @@ -0,0 +1,158 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/iio/dac/adi,ltc2672.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Analog Devices LTC2672 DAC
>> +
>> +maintainers:
>> + - Michael Hennerich <michael.hennerich@xxxxxxxxxx>
>> + - Kim Seer Paller <kimseer.paller@xxxxxxxxxx>
>> +
>> +description: |
>> + Analog Devices LTC2672 5 channel, 16 bit, 300mA DAC
>> + https://www.analog.com/media/en/technical-documentation/data-sheets/ltc2672.pdf
>> +
>> +properties:
>> + compatible:
>> + enum:
>> + - adi,ltc2672
>
> The linked datasheet describes 12-bit and 16-bit versions, so should we have
> two compatibles here? adi,ltc2672-12, adi,ltc2672-16
>
> I don't see any ID registers where this could be read from the chip at
> runtime, so seems like something that needs to be in the devicetree.

Hmm... I guess maybe it doesn't matter for these chips (i.e. the 4 LSBs
of the sample data register in 12-bit version will just always be ignored
but no data needs to be shifted based on the bit-ness).

I would not hurt to update the description though since it only mentions
16-bit if the compatible is meant for both versions of the chip.