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Commit 21dd19fe authored by Neil Armstrong's avatar Neil Armstrong Committed by David S. Miller
Browse files

net: phy: Add nested variants of mdiobus read/write 



Since nested variants of mdiobus_read/write are used in multiple
drivers, add nested variants in the mdiobus core.

Suggested-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6fb3b6b5

drivers/net/phy/mdio_bus.c

+55 −0
Original line number Diff line number Diff line
@@ -371,6 +371,33 @@ struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr) 
}

EXPORT_SYMBOL(mdiobus_scan);



/**

 * mdiobus_read_nested - Nested version of the mdiobus_read function

 * @bus: the mii_bus struct

 * @addr: the phy address

 * @regnum: register number to read

 *

 * In case of nested MDIO bus access avoid lockdep false positives by

 * using mutex_lock_nested().

 *

 * NOTE: MUST NOT be called from interrupt context,

 * because the bus read/write functions may wait for an interrupt

 * to conclude the operation.

 */

int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)

{

	int retval;



	BUG_ON(in_interrupt());



	mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING);

	retval = bus->read(bus, addr, regnum);

	mutex_unlock(&bus->mdio_lock);



	return retval;

}

EXPORT_SYMBOL(mdiobus_read_nested);



/**

 * mdiobus_read - Convenience function for reading a given MII mgmt register

 * @bus: the mii_bus struct
@@ -395,6 +422,34 @@ int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum) 
}

EXPORT_SYMBOL(mdiobus_read);



/**

 * mdiobus_write_nested - Nested version of the mdiobus_write function

 * @bus: the mii_bus struct

 * @addr: the phy address

 * @regnum: register number to write

 * @val: value to write to @regnum

 *

 * In case of nested MDIO bus access avoid lockdep false positives by

 * using mutex_lock_nested().

 *

 * NOTE: MUST NOT be called from interrupt context,

 * because the bus read/write functions may wait for an interrupt

 * to conclude the operation.

 */

int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)

{

	int err;



	BUG_ON(in_interrupt());



	mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING);

	err = bus->write(bus, addr, regnum, val);

	mutex_unlock(&bus->mdio_lock);



	return err;

}

EXPORT_SYMBOL(mdiobus_write_nested);



/**

 * mdiobus_write - Convenience function for writing a given MII mgmt register

 * @bus: the mii_bus struct

include/linux/phy.h

+2 −0
Original line number Diff line number Diff line
@@ -213,7 +213,9 @@ static inline struct mii_bus *devm_mdiobus_alloc(struct device *dev) 
void devm_mdiobus_free(struct device *dev, struct mii_bus *bus);

struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr);

int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum);

int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum);

int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val);

int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val);





#define PHY_INTERRUPT_DISABLED	0x0