MDIO_PHYACCESS_GO
if ((r & MDIO_PHYACCESS_GO) == 0)
cmd = MDIO_PHYACCESS_GO | (reg & 0x1F) << 21 | (phy & 0x1F) << 16;
cmd = MDIO_PHYACCESS_GO | MDIO_PHYACCESS_WRITE |