wm831x_power_check_online
ret = wm831x_power_check_online(wm831x, WM831X_PWR_USB, val);
ret = wm831x_power_check_online(wm831x, WM831X_PWR_SRC_BATT,
ret = wm831x_power_check_online(wm831x, WM831X_PWR_WALL, val);