HW_USBPHY_CTRL_CLKGATE
PHY_WR(sc, HW_USBPHY_CTRL_CLR, HW_USBPHY_CTRL_CLKGATE);
while (!(PHY_RD(sc, HW_USBPHY_CTRL) & HW_USBPHY_CTRL_CLKGATE))
PHY_WR(sc, HW_USBPHY_CTRL_CLR, HW_USBPHY_CTRL_CLKGATE);
while (PHY_RD(sc, HW_USBPHY_CTRL) & HW_USBPHY_CTRL_CLKGATE)