Re: [PATCH net-next RFC V1 5/5] net: mdio: Add a driver for InES time stamping IP core.

[Andrew Lunn <andrew@lunn.ch>]

On Wed, Mar 21, 2018 at 03:47:02PM -0700, Richard Cochran wrote:
> On Wed, Mar 21, 2018 at 11:16:52PM +0100, Andrew Lunn wrote:
> > The MAC drivers are clients of this device. They then use a phandle
> > and specifier:
> > 
> > 	eth0: ethernet-controller@72000 {
> > 		compatible = "marvell,kirkwood-eth";
> > 		#address-cells = <1>;
> > 		#size-cells = <0>;
> > 		reg = <0x72000 0x4000>;
> > 
> > 		timerstamper = <&timestamper 2>
> > 	}
> > 
> > The 2 indicates this MAC is using port 2.
> > 
> > The MAC driver can then do the standard device tree things to follow
> > the phandle to get access to the device and use the API it exports.
> 
> But that would require hacking every last MAC driver.
> 
> I happy to improve the modeling, but the solution should be generic
> and work for every MAC driver.

Something else to think about. There are a number of MAC drivers which
don't use phylib. All the intel drivers for example. They have their
own MDIO and PHY code. And recently there have been a number of MAC
drivers for hardware capable of > 1GBps which do all the PHY control
in firmware.

A phydev is optional, the MAC is mandatory.

  Andrew