Am Freitag, 19. Juni 2020, 07:01:58 CEST schrieb Florian Fainelli: > > On 6/18/2020 5:11 AM, Heiko Stuebner wrote: > > From: Heiko Stuebner <heiko.stuebner@xxxxxxxxxxxxxxxxxxxxx> > > > > Some mscc ethernet phys have a configurable clock output, so describe the > > generic properties to access them in devicetrees. > > > > Signed-off-by: Heiko Stuebner <heiko.stuebner@xxxxxxxxxxxxxxxxxxxxx> > > --- > > Documentation/devicetree/bindings/net/mscc-phy-vsc8531.txt | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/net/mscc-phy-vsc8531.txt b/Documentation/devicetree/bindings/net/mscc-phy-vsc8531.txt > > index 5ff37c68c941..67625ba27f53 100644 > > --- a/Documentation/devicetree/bindings/net/mscc-phy-vsc8531.txt > > +++ b/Documentation/devicetree/bindings/net/mscc-phy-vsc8531.txt > > @@ -1,6 +1,8 @@ > > * Microsemi - vsc8531 Giga bit ethernet phy > > > > Optional properties: > > +- clock-output-names : Name for the exposed clock output > > +- #clock-cells : should be 0 > > - vsc8531,vddmac : The vddmac in mV. Allowed values is listed > > in the first row of Table 1 (below). > > This property is only used in combination > > > > With that approach, you also need to be careful as a driver writer to > ensure that you have at least probed the MDIO bus to ensure that the PHY > device has been created (and therefore it is available as a clock > provider) if that same Ethernet MAC is a consumer of that clock (which > it appears to be). Otherwise you may just never probe and be trapped in > a circular dependency. Yep - although without anything like this, the phy won't emit any clock at all. Even when enabling the clock output in u-boot already, when the kernel starts that config is lost, so no existing board should break. As you can see in the discussion about patch 3/3 the wanted solution is not so clear cut as well. With Rob suggesting this clock-provider way and Russell strongly encouraging taking a second look. [My first iteration (till v4) was doing it like other phys by specifying a property to just tell the phy what frequency to output] I don't really have a preference for one or the other, so maybe you can also give a vote over there ;-) Heiko
