AR5K_PHY_NF_M
val = ath5k_hw_reg_read(ah, AR5K_PHY_NF) & ~AR5K_PHY_NF_M;
val |= (nf * 2) & AR5K_PHY_NF_M;
val = (val & ~AR5K_PHY_NF_M) | ((-50 * 2) & AR5K_PHY_NF_M);
#define AR5K_PHY_NF_SVAL(_n) (((_n) & AR5K_PHY_NF_M) | (1 << 9))