[PATCH 1/6] mdio_bus: Add generic mdio_find_bus()
From: Jeremy Linton <hidden>
Date: 2020-02-01 07:46:36
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
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 229e480179ff..46dfb112fd04 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c@@ -260,6 +260,23 @@ static struct class mdio_bus_class = { .dev_release = mdiobus_release, }; +/** + * 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 dd4a91f1feaa..5700dd4dbb6f 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h@@ -273,6 +273,7 @@ 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);
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2.24.1