Thread (9 messages) 9 messages, 4 authors, 2026-01-23

Re: [Proposal,Question - refresh] ACPI representation of DPLL/Ethernet dependencies (SyncE)

From: Andrew Lunn <andrew@lunn.ch>
Date: 2026-01-22 00:09:40
Also in: linux-acpi

* While the physical signals on these wires are indeed clocks (10MHz,
  etc.), from the OS driver perspective, this is not a "Clock Resource"
  issue. The NIC driver does not need to gate, rate-set, or power-manage
  these clocks (which is what _CRS/ClockInput implies).
Is this a peculiarity of the zl3073x? No gating, no rate-set, no power
management?

I had a quick look at the Renesas 8V89307 

https://www.renesas.com/en/document/dst/8v89307-final-data-sheet?r=177681

Two of the three inputs have an optional inverter. CCF has
clk_set_phase(), which when passed 180 would be a good model for this.
The inputs then have dividers which can be configured. I would
probably model them using CCF clk-divider.c for that. There is then a
mux, which clk-mux.c could model. After the DPLL there are more muxes
to optionally route the output through an APLL. The output block then
has yet more muxes and dividers.

All that could be described using a number of CCF parts chained
together in a clock tree.

And what about the TI LMK05028

https://www.ti.com/product/LMK05028

It also has inverters and muxes, but no dividers.

Analog Devices ad9546 also has lots of internal components which could
be described using CCF

https://www.analog.com/media/en/technical-documentation/data-sheets/ad9546.pdf

So i do wounder if we are being short sighted by using the clock
bindings but not Linux clocks.

	Andrew
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