[PATCH v2 1/6] mdio_bus: Add generic mdio_find_bus()
flat view
STALE2417d
From: Jeremy Linton <hidden>
Date: 2020-02-24 22:54:14
Also in:
lkml
Subsystem:
ethernet phy library, networking drivers, the rest · Maintainers:
Andrew Lunn, Heiner Kallweit, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Revision v2 of 2 in this series.
Revisions (2)
- v1 [diff vs current]
- v2 current
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 <redacted> --- drivers/net/phy/mdio_bus.c | 17 +++++++++++++++++ include/linux/phy.h | 1 + 2 files changed, 18 insertions(+)
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 c570e162e05e..bd4ac49a9dbe 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);
--
2.24.1