Re: [RESEND v2 1/2] dt-bindings: w1: Add YAML DT schema for AMD AXI w1 host and MAINTAINERS entry

From: Kris Chaplin
Date: Mon Oct 30 2023 - 12:32:25 EST


Thanks Rob,

On 30/10/2023 16:19, Rob Herring wrote:
Is there a device side implementation? I can't really imagine that
1-wire would ever be implemented as firmware on the device side given
its limited nature. So adding 'host' doesn't make this any more
specific.

There are slave drivers as well as master, although these do not have a device tree binding.

My question is whether there is slave/device IP for implementing the
device side in software? The slave drivers in the kernel are for
handling those devices, not a slave side controller interface.

For comparison, we have SPI slave in the kernel which is for
implementing the device side in software (running Linux or another
OS). There is no such thing in the kernel for 1-wire and I would doubt
there would ever be a software implementation. Could you, yes, but
given the limited nature of 1-wire why would you?

I agree - I'm not aware of any such interface or plans. Yes - I've seen it with SPI, but I've not heard anything similar for 1-wire.


The IP device from AMD is called "axi_1wire_host", and so we are hoping to stick with this binding if appropriate as it relates to the IP name.

Okay, I suppose that is good enough reason.

Thank you - it does help when we can align the binding and IP name.

However, the versioning comments in your first v2 have not been
addressed. I believe the conclusion was to mention the IP has a
version register. And Conor's R-by tag was not added.

I messed up with not adding a note about this to the commit on v2 which I can resolve in a v3 - yes the versioning is via register in the IP core at a known offset. The binding name (and IP name) changed between v1 and v2 (from master to host) so I didn't add the review tag for Conor in v2 as the commit changed.

regards,
Kris