GMAC_CLK_PIT
val &= ~(GMAC_CLK_PIT|GMAC_CLK_SRC);
val |= __SHIFTIN(GMAC_CLK_PIT_MII, GMAC_CLK_PIT);
val |= __SHIFTIN(GMAC_CLK_PIT_RGMII, GMAC_CLK_PIT);
sel = __SHIFTOUT(val, GMAC_CLK_PIT);