[PATCH 2/2] dt-bindings: net: dsa: mediatek,mt7530: document MDIO-bus

[Arınç ÜNAL]

On 30.04.2023 15:34, Arınç ÜNAL wrote:
> On 30.04.2023 14:28, David Bauer wrote:
>> Document the ability to add nodes for the MDIO bus connecting the
>> switch-internal PHYs.
> 
> This is quite interesting. Currently the PHY muxing feature for the 
> MT7530 switch looks for some fake ethernet-phy definitions on the 
> mdio-bus where the switch is also defined.
> 
> Looking at the binding here, there will be an mdio node under the switch 
> node. This could be useful to define the ethernet-phys for PHY muxing 
> here instead, so we don't waste the register addresses on the parent 
> mdio-bus for fake things. It looks like this should work right out of 
> the box. I will do some tests.

Once I start using the mdio node it forces me to define all the PHYs 
which were defined as ports.

[    4.159534] mt7530-mdio mdio-bus:1f lan0 (uninitialized): no phy at 1
[    4.166002] mt7530-mdio mdio-bus:1f lan0 (uninitialized): failed to 
connect to PHY: -ENODEV
[    4.174421] mt7530-mdio mdio-bus:1f lan0 (uninitialized): error -19 
setting up PHY for tree 0, switch 0, port 1
[    4.185236] mt7530-mdio mdio-bus:1f lan1 (uninitialized): no phy at 2
[    4.191753] mt7530-mdio mdio-bus:1f lan1 (uninitialized): failed to 
connect to PHY: -ENODEV
[    4.200150] mt7530-mdio mdio-bus:1f lan1 (uninitialized): error -19 
setting up PHY for tree 0, switch 0, port 2
[    4.210844] mt7530-mdio mdio-bus:1f lan2 (uninitialized): no phy at 3
[    4.217361] mt7530-mdio mdio-bus:1f lan2 (uninitialized): failed to 
connect to PHY: -ENODEV
[    4.225734] mt7530-mdio mdio-bus:1f lan2 (uninitialized): error -19 
setting up PHY for tree 0, switch 0, port 3
[    4.236394] mt7530-mdio mdio-bus:1f lan3 (uninitialized): no phy at 4
[    4.242901] mt7530-mdio mdio-bus:1f lan3 (uninitialized): failed to 
connect to PHY: -ENODEV
[    4.251297] mt7530-mdio mdio-bus:1f lan3 (uninitialized): error -19 
setting up PHY for tree 0, switch 0, port 4

We can either force defining the PHYs on the mdio node which would break 
the ABI, or forget about doing PHY muxing this way.

Arınç