devicetree: add DT_HAS_ALIAS()

[sslupsky]

It would be useful to have a DT_HAS_ALIAS() macro in devicetree.h similar to DT_HAS_NODE() for the situation where you use an alias to select the item from the device tree.

My example use case is debug pins where the pins are not dedicated for debug but are transient. So, the debug pins overlap existing GPIOs in the devicetree. I would like to use an alias for the debug pins and alias them to the existing GPIO pins. When I need to use them, I enable the alias in the devicetree overlay. When I no longer want to use them, I remove them from the overlay.

[sslupsky]

I think this will work

#define DT_HAS_ALIAS(alias_name) DT_HAS_NODE(DT_ALIAS(alias_name))

[henrikbrixandersen]

Why not simply use DT_HAS_NODE(DT_ALIAS(alias_name))?

[mbolivar-nordic]

DT_HAS_NODE(DT_ALIAS(foo)) is a valid implementation, yes. DT_ALIAS(foo) is a node identifier like any other, and DT_HAS_NODE() works with any node identifier.

@sslupsky would you be willing to send a patch? You could add this under DT_HAS_CHOSEN() in devicetree.h. Just make sure to add test cases in tests/lib/devicetree/src/main.c.

[sslupsky]

Sure, I can do that.

[mbolivar-nordic]

Thank you!

[kartben]

Sure, I can do that.

Are you still interested? :)

[zephyrbot]

Hi @galak,

This issue, marked as an Enhancement, was opened a while ago and did not get any traction. It was just assigned to you based on the labels. If you don't consider yourself the right person to address this issue, please re-assing it to the right person.

Please take a moment to review if the issue is still relevant to the project. If it is, please provide feedback and direction on how to move forward. If it is not, has already been addressed, is a duplicate, or is no longer relevant, please close it with a short comment explaining the reason.

@sslupsky you are also encouraged to help moving this issue forward by providing additional information and confirming this request/issue is still relevant to you.

Thanks!

[rruuaanng]

It has merged :). I'll close this issue

[rruuaanng]

#80511