AD7124 ADC burnout current source support

[moiflo033]

Hello, everyone. I was looking at utilizing the AD7124 burnout current source to detect open circuit conditions with a connected Wheatstone bridge.
Since there currently is no way to use them with Zephyr, i was looking at implementing this capability.
What would be the intended way to do this?
I saw that in PR #65934 biasing was implemented by adding a new property to the devicetree. Should this new feature be structured in a similar fashion?

Currently I'm thinking of adding a new property called "zephyr,burnout-source-strength" of type integer to each channel. This would then allow enabling or disabling the burnout source per channel with variable drive strength. This would behave similarly to the existing "zephyr,vbias-pins" and "zephyr,current-source-pin" properties, insofar as the interpretation of the field would be driver specific.

Similar hardware features are also available on other devices such as: AD4130, AD4170, MCP356x. All of which already have drivers.

Links:

• AD4130 Datasheet
• AD7124 Datasheet
• MCP356x Datasheet

[ljd42]

Hi @moiflo033 ,

Thanks for your patience.

Your approach sounds sensible to me. I'll double check with @MaureenHelm .
Happy to support you with the pull-request.

[MaureenHelm]

Sounds reasonable, thanks

[moiflo033]

Thank you so much for taking the time to look at this. I created a draft PR #104162 with an initial proposal. I don't have a board to test with yet, but it is in progress.