Re: [PATCH net-next 1/3] dt-bindings: net: dp83822: support configuring RMII master/slave mode

From: Jérémie Dautheribes
Date: Mon Mar 04 2024 - 11:32:22 EST


We are normally interested in this 50Mhz reference clock. So i would
drop all references to 25Mhz. It is not relevant to the binding, since
it is nothing to do with connecting the PHY to the MAC, and it has a
fixed value.

So you can simplify this down to:

RMII Master: Outputs a 50Mhz Reference clock which can be connected to the MAC.

RMII Slave: Expects a 50MHz Reference clock input, shared with the
MAC.

That said, would you like me to include this description (or some parts) in
the binding in addition to what I've already written? Or would you prefer me
to use a more meaningful property name?

We don't really have any vendor agnostic consistent naming. dp83867
and dp83869 seems to call this ti,clk-output-sel. Since this is
another dp83xxx device, it would be nice if there was consistency
between all these TI devices. So could you check if the concept is the
same, and if so, change dp83826 to follow what other TI devices do.


So I had a look at this ti,clk-output-sel property on the TI DP8386x
bindings, but unfortunately it does not correspond to our use case. In their
case, it is used to select one of the various internal clocks to output on
the CLK_OUT pin.
In our case, we would prefer to describe the direction of the clock (OUT in
master mode, IN in slave mode).

I would suggest we keep with the current property name, but simplify
the description. Focus on the reference clock, and ignore the crystal.


Ok noted, thanks for your feedback! I will send a v2 containing a simplified description + implement your suggested changes on patch 2.

Jérémie