Re: [PATCH 5/5] net: make mpc5200 fec driver use of_mdio infrastructure

On Tue, Mar 10, 2009 at 01:48:26PM -0600, Grant Likely wrote:
[...]

quoted

quoted

eliminates the assumption that the PHY for the FEC is always
attached to the FEC's own MDIO bus. With this patch, the FEC can
use a PHY attached to any MDIO bus if it is described in the device
tree.

AFAIK, Gianfar and UCC Geth drivers can do this too, so I'm assuming
that this isn't the cause for these major changes.

Certainly the mpc5200-fec driver's original phy code certainly wasn't
as robust as the ucc_geth and gianfar phy handling.

ucc_geth open codes a solution to decode the phy_device name from
several nodes in the device tree and doesn't handle the case where the
ucc_geth is initialized before the phy_device is registered.  gianfar
open codes the same thing.  This solution uses common code to locate
the phy_device, and it works regardless of what order devices are
registered in.

That being said, the 5200 driver originally using probe() time to
connect to the phy.  If I change it to be connected at open time, then
does the registration order issue become irrelevant?

Yup. `ifconfig ethX up' calls ->open(). If it fails (and prints
nice error), you can try `ifconfig ethX up' again later.

Regardless, I
think all the drivers should be using common code for obtaining the
phy_device from the device tree.

Not necessary `struct phy_device'. All we need is some common
routine for translating PHY's "mdio_node->full_name + phy id" to
phy_bus_id.

That is, you can just factor out this code from the gianfar driver,

void gfar_mdio_bus_name(char *name, struct device_node *np)
{
        const u32 *reg;

        reg = of_get_property(np, "reg", NULL);

        snprintf(name, MII_BUS_ID_SIZE, "%s@%x", np->name, reg ? *reg : 0);
}

...
        gfar_mdio_bus_name(bus_name, mdio);
        snprintf(priv->phy_bus_id, sizeof(priv->phy_bus_id), "%s:%02x",
                 bus_name, *id);
...

And make sure FEC MDIO driver does mdio_bus->parent = &ofdev->dev;

-- 
Anton Vorontsov
email: cbouatmailru@gmail.com
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