Re: [PATCH net-next v2 3/7] net: macb: parse PHY nodes found under an MDIO node

[Florian Fainelli]

On 7/21/20 10:13 AM, Codrin Ciubotariu wrote:
> The MACB embeds an MDIO bus controller. For this reason, the PHY nodes
> were represented as sub-nodes in the MACB node. Generally, the
> Ethernet controller is different than the MDIO controller, so the PHYs
> are probed by a separate MDIO driver. Since adding the PHY nodes directly
> under the ETH node became deprecated, we adjust the MACB driver to look
> for an MDIO node and register the subnode MDIO devices.
> 
> Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@xxxxxxxxxxxxx>
> ---
> 
> Changes in v2:
>  - readded newline removed by mistake;
> 
>  drivers/net/ethernet/cadence/macb_main.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index 89fe7af5e408..b25c64b45148 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -740,10 +740,20 @@ static int macb_mii_probe(struct net_device *dev)
>  static int macb_mdiobus_register(struct macb *bp)
>  {
>  	struct device_node *child, *np = bp->pdev->dev.of_node;
> +	struct device_node *mdio_node;
> +	int ret;
>  
>  	if (of_phy_is_fixed_link(np))
>  		return mdiobus_register(bp->mii_bus);

Does not this need changing as well? Consider the use case of having
your MACB Ethernet node have a fixed-link property to describe how it
connects to a switch, and your MACB MDIO controller, expressed as a
sub-node, describing the MDIO attached switch it connects to.

>  
> +	/* if an MDIO node is present, it should contain the PHY nodes */
> +	mdio_node = of_get_child_by_name(np, "mdio");
> +	if (mdio_node) {
> +		ret = of_mdiobus_register(bp->mii_bus, mdio_node);
> +		of_node_put(mdio_node);
> +		return ret;
> +	}
> +
>  	/* Only create the PHY from the device tree if at least one PHY is
>  	 * described. Otherwise scan the entire MDIO bus. We do this to support
>  	 * old device tree that did not follow the best practices and did not
> 


-- 
Florian