AR5K_TSF_U32
tsf_upper1 = ath5k_hw_reg_read(ah, AR5K_TSF_U32);
tsf_upper2 = ath5k_hw_reg_read(ah, AR5K_TSF_U32);
ath5k_hw_reg_write(ah, (tsf64 >> 32) & 0xffffffff, AR5K_TSF_U32);
tsf_up = ath5k_hw_reg_read(ah, AR5K_TSF_U32);
ath5k_hw_reg_write(ah, tsf_up, AR5K_TSF_U32);