Convenience function for writing a given mii mgmt register
int mdiobus_write(struct mii_bus * bus, int addr, u32 regnum, u16 val);
bus
the mii_bus struct
addr
the phy address
regnum
register number to write
val
value to write to regnum
MUST NOT be called from interrupt context, because the bus read/write functions may wait for an interrupt to conclude the operation.