Re: [PATCH 1/6] dt-bindings: adc: ad7173: add support for ad411x

Ceclan, Dumitru
2024-05-16T08:18:40Z

On 16/05/2024 00:42, David Lechner wrote:
> On Sat, Apr 20, 2024 at 9:33 AM Jonathan Cameron <jic23@kernel.org> wrote:
>>
>> On Mon, 15 Apr 2024 21:42:50 +0300
>> "Ceclan, Dumitru" <mitrutzceclan@gmail.com> wrote:
>>
>>> On 13/04/2024 13:49, Jonathan Cameron wrote:
>>>> On Tue, 9 Apr 2024 11:08:28 +0300
>>>> "Ceclan, Dumitru" <mitrutzceclan@gmail.com> wrote:
>>>>
>>>>> On 06/04/2024 17:53, Jonathan Cameron wrote:
>>>>>> On Wed, 3 Apr 2024 10:40:39 -0500
>>>>>> David Lechner <dlechner@baylibre.com> wrote:
>>>>>>
>>>>>>> On Wed, Apr 3, 2024 at 2:43 AM Ceclan, Dumitru <mitrutzceclan@gmail.com> wrote:
>>>>>>>>
>>>>>>>> On 01/04/2024 22:37, David Lechner wrote:
>>>>>>>>> On Mon, Apr 1, 2024 at 10:10 AM Dumitru Ceclan via B4 Relay
>>>>>>>>> <devnull+dumitru.ceclan.analog.com@kernel.org> wrote:
>>>>>>>>>>
>>>>>>>>>> From: Dumitru Ceclan <dumitru.ceclan@analog.com>
>>>>>>>>
>>> ...
>>>>>
>>>>>>>> Other alternative that came to my mind: attribute "adi,current-channel".
>>>>>>>
>>>>>>> Having a boolean flag like this would make more sense to me if we
>>>>>>> don't agree that the suggestion below is simpler.
>>>>>>>
>>>
>>> ...
>>>
>>>>
>>>> We do directly relate reg to channel numbers in drivers like the ad7292 (where not
>>>> all channels are differential) I'm not convinced either way on what is best
>>>> here where reg is currently just an index into a channel specification, not
>>>> meaningful for which pins are involved.
>>>>
>>>> It doesn't seem worth adding an equivalent of diff-channels for a single channel
>>>> setup but I guess it would be more consistent.
>>>>
>>>
>>> Would you agree with the attribute adi,current-channel within the channel and
>>> diff-channels set to the correspondent current inputs (13 10 for pair IN2)?
>>
>> From another thread today I've concluded we do need a single-channel
>> equivalent of diff-channels, but you are right that here it is a differential
>> channel so <13 10> seems like the best option to me.
>>
>
> Current inputs are differential? It seems like we would need 4 input
> pins for that.
We cannot measure differential current channels.
We are measuring a voltage differential channel of the voltage drop across
the shunt resistor. Differential in the sense that inputs 13 and 10 are
routed to the ADC.