ath5k: use noise calibration from madwifi hal

This updates ath5k to calibrate the noise floor similar to the
way it is done in the madwifi hal and ath9k.  Of note:

- we start NF measurement at the same time as AGC calibration,
  but do not actually read the value until the periodic (long)
  calibration
- we keep a history of the last few values read and write the
  median back to the hardware for CCA
- we do not complain if NF calibration isn't complete, instead
  we keep the last read value.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath5k/ath5k.h b/drivers/net/wireless/ath/ath5k/ath5k.h
index 647d826bf5fb..6a2a96761111 100644
--- a/drivers/net/wireless/ath/ath5k/ath5k.h
+++ b/drivers/net/wireless/ath/ath5k/ath5k.h
@@ -198,6 +198,7 @@
 #define AR5K_TUNE_CWMAX_11B			1023
 #define AR5K_TUNE_CWMAX_XR			7
 #define AR5K_TUNE_NOISE_FLOOR			-72
+#define AR5K_TUNE_CCA_MAX_GOOD_VALUE		-95
 #define AR5K_TUNE_MAX_TXPOWER			63
 #define AR5K_TUNE_DEFAULT_TXPOWER		25
 #define AR5K_TUNE_TPC_TXPOWER			false
@@ -1006,6 +1007,14 @@ struct ath5k_capabilities {
 	} cap_queues;
 };
 
+/* size of noise floor history (keep it a power of two) */
+#define ATH5K_NF_CAL_HIST_MAX	8
+struct ath5k_nfcal_hist
+{
+	s16 index;				/* current index into nfval */
+	s16 nfval[ATH5K_NF_CAL_HIST_MAX];	/* last few noise floors */
+};
+
 
 /***************************************\
   HARDWARE ABSTRACTION LAYER STRUCTURE
@@ -1112,6 +1121,8 @@ struct ath5k_hw {
 		struct ieee80211_channel r_last_channel;
 	} ah_radar;
 
+	struct ath5k_nfcal_hist ah_nfcal_hist;
+
 	/* noise floor from last periodic calibration */
 	s32			ah_noise_floor;
 
@@ -1274,8 +1285,10 @@ extern int ath5k_hw_rfgain_opt_init(struct ath5k_hw *ah);
 extern bool ath5k_channel_ok(struct ath5k_hw *ah, u16 freq, unsigned int flags);
 extern int ath5k_hw_channel(struct ath5k_hw *ah, struct ieee80211_channel *channel);
 /* PHY calibration */
+void ath5k_hw_init_nfcal_hist(struct ath5k_hw *ah);
 extern int ath5k_hw_phy_calibrate(struct ath5k_hw *ah, struct ieee80211_channel *channel);
 extern int ath5k_hw_noise_floor_calibration(struct ath5k_hw *ah, short freq);
+extern s16 ath5k_hw_get_noise_floor(struct ath5k_hw *ah);
 extern void ath5k_hw_calibration_poll(struct ath5k_hw *ah);
 /* Spur mitigation */
 bool ath5k_hw_chan_has_spur_noise(struct ath5k_hw *ah,