ah->ah_swi_mask = AR5K_SWI_FULL_CALIBRATION;
AR5K_REG_ENABLE_BITS(ah, AR5K_CR, AR5K_CR_SWI);
}
+}
+static int sign_extend(int val, const int nbits)
+{
+ int order = BIT(nbits-1);
+ return (val ^ order) - order;
}
-/**
- * ath5k_hw_noise_floor_calibration - perform PHY noise floor calibration
- *
- * @ah: struct ath5k_hw pointer we are operating on
- * @freq: the channel frequency, just used for error logging
- *
- * This function performs a noise floor calibration of the PHY and waits for
- * it to complete. Then the noise floor value is compared to some maximum
- * noise floor we consider valid.
- *
- * Note that this is different from what the madwifi HAL does: it reads the
- * noise floor and afterwards initiates the calibration. Since the noise floor
- * calibration can take some time to finish, depending on the current channel
- * use, that avoids the occasional timeout warnings we are seeing now.
- *
- * See the following link for an Atheros patent on noise floor calibration:
- * http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL \
- * &p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7245893.PN.&OS=PN/7
+static s32 ath5k_hw_read_measured_noise_floor(struct ath5k_hw *ah)
+{
+ s32 val;
+
+ val = ath5k_hw_reg_read(ah, AR5K_PHY_NF);
+ return sign_extend(AR5K_REG_MS(val, AR5K_PHY_NF_MINCCA_PWR), 9);
+}
+
+void ath5k_hw_init_nfcal_hist(struct ath5k_hw *ah)
+{
+ int i;
+
+ ah->ah_nfcal_hist.index = 0;
+ for (i = 0; i < ATH5K_NF_CAL_HIST_MAX; i++)
+ ah->ah_nfcal_hist.nfval[i] = AR5K_TUNE_CCA_MAX_GOOD_VALUE;
+}
+
+static void ath5k_hw_update_nfcal_hist(struct ath5k_hw *ah, s16 noise_floor)
+{
+ struct ath5k_nfcal_hist *hist = &ah->ah_nfcal_hist;
+ hist->index = (hist->index + 1) & (ATH5K_NF_CAL_HIST_MAX-1);
+ hist->nfval[hist->index] = noise_floor;
+}
+
+static s16 ath5k_hw_get_median_noise_floor(struct ath5k_hw *ah)
+{
+ s16 sort[ATH5K_NF_CAL_HIST_MAX];
+ s16 tmp;
+ int i, j;
+
+ memcpy(sort, ah->ah_nfcal_hist.nfval, sizeof(sort));
+ for (i = 0; i < ATH5K_NF_CAL_HIST_MAX - 1; i++) {
+ for (j = 1; j < ATH5K_NF_CAL_HIST_MAX - i; j++) {
+ if (sort[j] > sort[j-1]) {
+ tmp = sort[j];
+ sort[j] = sort[j-1];
+ sort[j-1] = tmp;
+ }
+ }
+ }
+ for (i = 0; i < ATH5K_NF_CAL_HIST_MAX; i++) {
+ ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_CALIBRATE,
+ "cal %d:%d\n", i, sort[i]);
+ }
+ return sort[(ATH5K_NF_CAL_HIST_MAX-1) / 2];
+}
+
+/*
+ * When we tell the hardware to perform a noise floor calibration
+ * by setting the AR5K_PHY_AGCCTL_NF bit, it will periodically
+ * sample-and-hold the minimum noise level seen at the antennas.
+ * This value is then stored in a ring buffer of recently measured
+ * noise floor values so we have a moving window of the last few
+ * samples.
*
- * XXX: Since during noise floor calibration antennas are detached according to
- * the patent, we should stop tx queues here.
+ * The median of the values in the history is then loaded into the
+ * hardware for its own use for RSSI and CCA measurements.
*/
-int
-ath5k_hw_noise_floor_calibration(struct ath5k_hw *ah, short freq)
+void ath5k_hw_update_noise_floor(struct ath5k_hw *ah)
{
- int ret;
- unsigned int i;
- s32 noise_floor;
+ struct ath5k_eeprom_info *ee = &ah->ah_capabilities.cap_eeprom;
+ u32 val;
+ s16 nf, threshold;
+ u8 ee_mode;
- /*
- * Enable noise floor calibration
- */
- AR5K_REG_ENABLE_BITS(ah, AR5K_PHY_AGCCTL,
- AR5K_PHY_AGCCTL_NF);
+ /* keep last value if calibration hasn't completed */
+ if (ath5k_hw_reg_read(ah, AR5K_PHY_AGCCTL) & AR5K_PHY_AGCCTL_NF) {
+ ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_CALIBRATE,
+ "NF did not complete in calibration window\n");
- ret = ath5k_hw_register_timeout(ah, AR5K_PHY_AGCCTL,
- AR5K_PHY_AGCCTL_NF, 0, false);
- if (ret) {
- ATH5K_ERR(ah->ah_sc,
- "noise floor calibration timeout (%uMHz)\n", freq);
- return -EAGAIN;
+ return;
}
- /* Wait until the noise floor is calibrated and read the value */
- for (i = 20; i > 0; i--) {
- mdelay(1);
- noise_floor = ath5k_hw_reg_read(ah, AR5K_PHY_NF);
- noise_floor = AR5K_PHY_NF_RVAL(noise_floor);
- if (noise_floor & AR5K_PHY_NF_ACTIVE) {
- noise_floor = AR5K_PHY_NF_AVAL(noise_floor);
-
- if (noise_floor <= AR5K_TUNE_NOISE_FLOOR)
- break;
- }
+ switch (ah->ah_current_channel->hw_value & CHANNEL_MODES) {
+ case CHANNEL_A:
+ case CHANNEL_T:
+ case CHANNEL_XR:
+ ee_mode = AR5K_EEPROM_MODE_11A;
+ break;
+ case CHANNEL_G:
+ case CHANNEL_TG:
+ ee_mode = AR5K_EEPROM_MODE_11G;
+ break;
+ default:
+ case CHANNEL_B:
+ ee_mode = AR5K_EEPROM_MODE_11B;
+ break;
}
- ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_CALIBRATE,
- "noise floor %d\n", noise_floor);
- if (noise_floor > AR5K_TUNE_NOISE_FLOOR) {
- ATH5K_ERR(ah->ah_sc,
- "noise floor calibration failed (%uMHz)\n", freq);
- return -EAGAIN;
+ /* completed NF calibration, test threshold */
+ nf = ath5k_hw_read_measured_noise_floor(ah);
+ threshold = ee->ee_noise_floor_thr[ee_mode];
+
+ if (nf > threshold) {
+ ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_CALIBRATE,
+ "noise floor failure detected; "
+ "read %d, threshold %d\n",
+ nf, threshold);
+
+ nf = AR5K_TUNE_CCA_MAX_GOOD_VALUE;
}
- ah->ah_noise_floor = noise_floor;
+ ath5k_hw_update_nfcal_hist(ah, nf);
+ nf = ath5k_hw_get_median_noise_floor(ah);
- return 0;
+ /* load noise floor (in .5 dBm) so the hardware will use it */
+ val = ath5k_hw_reg_read(ah, AR5K_PHY_NF) & ~AR5K_PHY_NF_M;
+ val |= (nf * 2) & AR5K_PHY_NF_M;
+ ath5k_hw_reg_write(ah, val, AR5K_PHY_NF);
+
+ AR5K_REG_MASKED_BITS(ah, AR5K_PHY_AGCCTL, AR5K_PHY_AGCCTL_NF,
+ ~(AR5K_PHY_AGCCTL_NF_EN | AR5K_PHY_AGCCTL_NF_NOUPDATE));
+
+ ath5k_hw_register_timeout(ah, AR5K_PHY_AGCCTL, AR5K_PHY_AGCCTL_NF,
+ 0, false);
+
+ /*
+ * Load a high max CCA Power value (-50 dBm in .5 dBm units)
+ * so that we're not capped by the median we just loaded.
+ * This will be used as the initial value for the next noise
+ * floor calibration.
+ */
+ val = (val & ~AR5K_PHY_NF_M) | ((-50 * 2) & AR5K_PHY_NF_M);
+ ath5k_hw_reg_write(ah, val, AR5K_PHY_NF);
+ AR5K_REG_ENABLE_BITS(ah, AR5K_PHY_AGCCTL,
+ AR5K_PHY_AGCCTL_NF_EN |
+ AR5K_PHY_AGCCTL_NF_NOUPDATE |
+ AR5K_PHY_AGCCTL_NF);
+
+ ah->ah_noise_floor = nf;
+
+ ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_CALIBRATE,
+ "noise floor calibrated: %d\n", nf);
}
/*
return ret;
}
- ath5k_hw_noise_floor_calibration(ah, channel->center_freq);
+ ath5k_hw_update_noise_floor(ah);
/*
* Re-enable RX/TX and beacons
* since noise floor calibration interrupts rx path while I/Q
* calibration doesn't. We don't need to run noise floor calibration
* as often as I/Q calibration.*/
- ath5k_hw_noise_floor_calibration(ah, channel->center_freq);
+ ath5k_hw_update_noise_floor(ah);
/* Initiate a gain_F calibration */
ath5k_hw_request_rfgain_probe(ah);
projects / karo-tx-linux.git / commitdiff