diff options
author | Jeremy Linton <jeremy.linton@arm.com> | 2020-02-25 01:53:58 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2020-02-25 02:31:23 +0300 |
commit | ce69e2162f158d9d4a0e513971d02dabc7d14cb7 (patch) | |
tree | 2fc144771e32d66fda00288b1df25725b535a5ef | |
parent | cc5b48b567a2f668d6f301cb0dd08d65ff1f7fa2 (diff) | |
download | linux-ce69e2162f158d9d4a0e513971d02dabc7d14cb7.tar.xz |
mdio_bus: Add generic mdio_find_bus()
It appears most ethernet drivers follow one of two main strategies
for mdio bus/phy management. A monolithic model where the net driver
itself creates, probes and uses the phy, and one where an external
mdio/phy driver instantiates the mdio bus/phy and the net driver
only attaches to a known phy. Usually in this latter model the phys
are discovered via DT relationships or simply phy name/address
hardcoding.
This is a shame because modern well behaved mdio buses are self
describing and can be probed. The mdio layer itself is fully capable
of this, yet there isn't a clean way for a standalone net driver
to attach and enumerate the discovered devices. This is because
outside of of_mdio_find_bus() there isn't a straightforward way
to acquire the mii_bus pointer.
So, lets add a mdio_find_bus which can return the mii_bus based
only on its name.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | drivers/net/phy/mdio_bus.c | 17 | ||||
-rw-r--r-- | include/linux/phy.h | 1 |
2 files changed, 18 insertions, 0 deletions
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 9bb9f37f21dc..3ab9ca7614d1 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -462,6 +462,23 @@ static struct class mdio_bus_class = { .dev_groups = mdio_bus_groups, }; +/** + * mdio_find_bus - Given the name of a mdiobus, find the mii_bus. + * @mdio_bus_np: Pointer to the mii_bus. + * + * Returns a reference to the mii_bus, or NULL if none found. The + * embedded struct device will have its reference count incremented, + * and this must be put_deviced'ed once the bus is finished with. + */ +struct mii_bus *mdio_find_bus(const char *mdio_name) +{ + struct device *d; + + d = class_find_device_by_name(&mdio_bus_class, mdio_name); + return d ? to_mii_bus(d) : NULL; +} +EXPORT_SYMBOL(mdio_find_bus); + #if IS_ENABLED(CONFIG_OF_MDIO) /** * of_mdio_find_bus - Given an mii_bus node, find the mii_bus. diff --git a/include/linux/phy.h b/include/linux/phy.h index 80f8b2158271..e72dbd0d2d6a 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -289,6 +289,7 @@ static inline struct mii_bus *devm_mdiobus_alloc(struct device *dev) return devm_mdiobus_alloc_size(dev, 0); } +struct mii_bus *mdio_find_bus(const char *mdio_name); void devm_mdiobus_free(struct device *dev, struct mii_bus *bus); struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr); |