Subject: Re: [PATCH v1 1/7] mdio_bus: Introduce fwnode MDIO helpers

From: Andrew Lunn <[email-masked]>
Date: Tue, 17 Mar 2020 15:04:26 +0100

On Tue, Mar 17, 2020 at 05:06:50PM +0530, Calvin Johnson wrote:
> Hi,
> 
> On Fri, Jan 31, 2020 at 09:04:34PM +0530, Calvin Johnson wrote:
> 
> <snip>
> 
> > +/**
> > + * fwnode_mdiobus_child_is_phy - Return true if the child is a PHY node.
> > + * It must either:
> > + * o Compatible string of "ethernet-phy-ieee802.3-c45"
> > + * o Compatible string of "ethernet-phy-ieee802.3-c22"
> > + * Checking "compatible" property is done, in order to follow the DT binding.
> > + */
> > +static bool fwnode_mdiobus_child_is_phy(struct fwnode_handle *child)
> > +{
> > +	int ret;
> > +
> > +	ret = fwnode_property_match_string(child, "compatible",
> > +					   "ethernet-phy-ieee802.3-c45");
> > +	if (!ret)
> > +		return true;
> > +
> > +	ret = fwnode_property_match_string(child, "compatible",
> > +					   "ethernet-phy-ieee802.3-c22");
> > +	if (!ret)
> > +		return true;
> > +
> > +	if (!fwnode_property_present(child, "compatible"))
> > +		return true;
> > +
> > +	return false;
> > +}
> 
> Can we use _CID in ACPI to get the compatible string? Is there any other method
> to handle this kind of situation where we would like to pass C45 or C22 info to
> the mdiobus driver?

Hi Calvin

Is there any defacto standardised way to stuff this device tree
property into ACPI? It is one of the key properties, so either there
is one standard way, or lots of variants because nobody can be
bothered to go to the ACPI standardisation body and get it formalised.

     Andrew