From 6cc7cf8125b3d086cd80c96e02edb6f4ab9b20fa Mon Sep 17 00:00:00 2001 From: Russell King Date: Tue, 17 Mar 2020 14:52:31 +0000 Subject: net: mdiobus: add APIs for modifying a MDIO device register Add APIs for modifying a MDIO device register, similar to the existing phy_modify() group of functions, but at mdiobus level instead. Adapt __phy_modify_changed() to use the new mdiobus level helper. Signed-off-by: Russell King Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- drivers/net/phy/mdio_bus.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) (limited to 'drivers/net/phy/mdio_bus.c') diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 129e60630319..522760c8bca6 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -824,6 +824,38 @@ int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val) } EXPORT_SYMBOL(__mdiobus_write); +/** + * __mdiobus_modify_changed - Unlocked version of the mdiobus_modify function + * @bus: the mii_bus struct + * @addr: the phy address + * @regnum: register number to modify + * @mask: bit mask of bits to clear + * @set: bit mask of bits to set + * + * Read, modify, and if any change, write the register value back to the + * device. Any error returns a negative number. + * + * NOTE: MUST NOT be called from interrupt context. + */ +int __mdiobus_modify_changed(struct mii_bus *bus, int addr, u32 regnum, + u16 mask, u16 set) +{ + int new, ret; + + ret = __mdiobus_read(bus, addr, regnum); + if (ret < 0) + return ret; + + new = (ret & ~mask) | set; + if (new == ret) + return 0; + + ret = __mdiobus_write(bus, addr, regnum, new); + + return ret < 0 ? ret : 1; +} +EXPORT_SYMBOL_GPL(__mdiobus_modify_changed); + /** * mdiobus_read_nested - Nested version of the mdiobus_read function * @bus: the mii_bus struct @@ -932,6 +964,30 @@ int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val) } EXPORT_SYMBOL(mdiobus_write); +/** + * mdiobus_modify - Convenience function for modifying a given mdio device + * register + * @bus: the mii_bus struct + * @addr: the phy address + * @regnum: register number to write + * @mask: bit mask of bits to clear + * @set: bit mask of bits to set + */ +int mdiobus_modify(struct mii_bus *bus, int addr, u32 regnum, u16 mask, u16 set) +{ + int err; + + if (WARN_ON_ONCE(in_interrupt())) + return -EINVAL; + + mutex_lock(&bus->mdio_lock); + err = __mdiobus_modify_changed(bus, addr, regnum, mask, set); + mutex_unlock(&bus->mdio_lock); + + return err < 0 ? err : 0; +} +EXPORT_SYMBOL_GPL(mdiobus_modify); + /** * mdio_bus_match - determine if given MDIO driver supports the given * MDIO device -- cgit