On Tue, Aug 20, 2019 at 11:34 AM Ondřej Jirman [off-list ref] wrote:

On Tue, Aug 20, 2019 at 11:20:22AM -0500, Rob Herring wrote:

quoted

On Tue, Aug 20, 2019 at 9:53 AM [off-list ref] wrote:

quoted

From: Ondrej Jirman <redacted>

Some PHYs require separate power supply for I/O pins in some modes
of operation. Add phy-io-supply property, to allow enabling this
power supply.

Perhaps since this is new, such phys should have *-supply in their nodes.

Yes, I just don't understand, since external ethernet phys are so common,
and they require power, how there's no fairly generic mechanism for this
already in the PHY subsystem, or somewhere?

Because generic mechanisms for this don't work. For example, what
happens when the 2 supplies need to be turned on in a certain order
and with certain timings? And then add in reset or control lines into
the mix... You can see in the bindings we already have some of that.

It looks like other ethernet mac drivers also implement supplies on phys
on the EMAC nodes. Just grep phy-supply through dt-bindings/net.

Historical reasons, or am I missing something? It almost seems like I must
be missing something, since putting these properties to phy nodes
seems so obvious.

Things get added one by one and one new property isn't that
controversial. We've generally learned the lesson and avoid this
pattern now, but ethernet phys are one of the older bindings.

Rob