Hi Niklas,
On Sat, Mar 9, 2024 at 4:55 PM Niklas Söderlund
<niklas.soderlund+renesas@xxxxxxxxxxxx> wrote:
> The driver used the OF node of the device itself when registering the
> MDIO bus. While this works it creates a problem, it forces any MDIO bus
> properties to also be set on the devices OF node. This mixes the
> properties of two distinctly different things and is confusing.
>
> This change adds support for an optional mdio node to be defined as a
> child to the device OF node. The child node can then be used to describe
> MDIO bus properties that the MDIO core can act on when registering the
> bus.
>
> If no mdio child node is found the driver fallback to the old behavior
> and register the MDIO bus using the device OF node. This change is
> backward compatible with old bindings in use.
>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
Thanks for your patch!
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -2582,8 +2583,20 @@ static int ravb_mdio_init(struct ravb_private *priv)
> snprintf(priv->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",
> pdev->name, pdev->id);
>
> - /* Register MDIO bus */
> - error = of_mdiobus_register(priv->mii_bus, dev->of_node);
> + /* Register MDIO bus
> + *
> + * Look for a mdio child node, if it exist use it when registering the
> + * MDIO bus. If no node is found fallback to old behavior and use the
> + * device OF node. This is used to be able to describe MDIO bus
> + * properties that are consumed when registering the MDIO bus.
> + */
> + mdio_node = of_get_child_by_name(dev->of_node, "mdio");
> + if (mdio_node) {
> + error = of_mdiobus_register(priv->mii_bus, mdio_node);
> + of_node_put(mdio_node);
> + } else {
> + error = of_mdiobus_register(priv->mii_bus, dev->of_node);
> + }
> if (error)
> goto out_free_bus;
>
Perhaps the code should be streamlined for the modern case?
mdio_node = of_get_child_by_name(dev->of_node, "mdio");
if (!mdio_node) {
/* backwards compatibility for DT lacking mdio subnode */
mdio_node = of_node_get(dev->of_node);
}
error = of_mdiobus_register(priv->mii_bus, mdio_node);
of_node_put(mdio_node);
When deemed necessary, you can easily replace the backwards
compatibility handling by error handling later.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
