ath5k: Reimplement clock rate to usec conversion

The original code was correct in 802.11a mode only, 802.11b/g uses
different clock rates. The new code uses values taken from FreeBSD HAL
and should be correct for all modes including turbo modes.

The former rate calculation was used by slope coefficient calculation
function ath5k_hw_write_ofdm_timings. However, this function requires
the 802.11a values even in 802.11g mode. Thus the use of
ath5k_hw_htoclock was replaced by hardcoded values. Possibly the slope
coefficient calculation is not related to clock rate at all.

Signed-off-by: Lukas Turek <8an@praha12.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 54 insertions, 10 deletions

diff --git a/drivers/net/wireless/ath/ath5k/pcu.c b/drivers/net/wireless/ath/ath5k/pcu.c
index 64fc1eb9b6d9..b601ff9865fd 100644
--- a/drivers/net/wireless/ath/ath5k/pcu.c
+++ b/drivers/net/wireless/ath/ath5k/pcu.c
@@ -187,8 +187,8 @@ unsigned int ath5k_hw_get_ack_timeout(struct ath5k_hw *ah)
 {
         ATH5K_TRACE(ah->ah_sc);
 
-        return ath5k_hw_clocktoh(AR5K_REG_MS(ath5k_hw_reg_read(ah,
-                        AR5K_TIME_OUT), AR5K_TIME_OUT_ACK), ah->ah_turbo);
+        return ath5k_hw_clocktoh(ah, AR5K_REG_MS(ath5k_hw_reg_read(ah,
+                        AR5K_TIME_OUT), AR5K_TIME_OUT_ACK));
 }
 
 /**
@@ -200,12 +200,12 @@ unsigned int ath5k_hw_get_ack_timeout(struct ath5k_hw *ah)
 int ath5k_hw_set_ack_timeout(struct ath5k_hw *ah, unsigned int timeout)
 {
         ATH5K_TRACE(ah->ah_sc);
-        if (ath5k_hw_clocktoh(AR5K_REG_MS(0xffffffff, AR5K_TIME_OUT_ACK),
-                        ah->ah_turbo) <= timeout)
+        if (ath5k_hw_clocktoh(ah, AR5K_REG_MS(0xffffffff, AR5K_TIME_OUT_ACK))
+                        <= timeout)
                 return -EINVAL;
 
         AR5K_REG_WRITE_BITS(ah, AR5K_TIME_OUT, AR5K_TIME_OUT_ACK,
-                ath5k_hw_htoclock(timeout, ah->ah_turbo));
+                ath5k_hw_htoclock(ah, timeout));
 
         return 0;
 }
@@ -218,8 +218,8 @@ int ath5k_hw_set_ack_timeout(struct ath5k_hw *ah, unsigned int timeout)
 unsigned int ath5k_hw_get_cts_timeout(struct ath5k_hw *ah)
 {
         ATH5K_TRACE(ah->ah_sc);
-        return ath5k_hw_clocktoh(AR5K_REG_MS(ath5k_hw_reg_read(ah,
-                        AR5K_TIME_OUT), AR5K_TIME_OUT_CTS), ah->ah_turbo);
+        return ath5k_hw_clocktoh(ah, AR5K_REG_MS(ath5k_hw_reg_read(ah,
+                        AR5K_TIME_OUT), AR5K_TIME_OUT_CTS));
 }
 
 /**
@@ -231,17 +231,61 @@ unsigned int ath5k_hw_get_cts_timeout(struct ath5k_hw *ah)
 int ath5k_hw_set_cts_timeout(struct ath5k_hw *ah, unsigned int timeout)
 {
         ATH5K_TRACE(ah->ah_sc);
-        if (ath5k_hw_clocktoh(AR5K_REG_MS(0xffffffff, AR5K_TIME_OUT_CTS),
-                        ah->ah_turbo) <= timeout)
+        if (ath5k_hw_clocktoh(ah, AR5K_REG_MS(0xffffffff, AR5K_TIME_OUT_CTS))
+                        <= timeout)
                 return -EINVAL;
 
         AR5K_REG_WRITE_BITS(ah, AR5K_TIME_OUT, AR5K_TIME_OUT_CTS,
-                        ath5k_hw_htoclock(timeout, ah->ah_turbo));
+                        ath5k_hw_htoclock(ah, timeout));
 
         return 0;
 }
 
 /**
+ * ath5k_hw_htoclock - Translate usec to hw clock units
+ *
+ * @ah: The &struct ath5k_hw
+ * @usec: value in microseconds
+ */
+unsigned int ath5k_hw_htoclock(struct ath5k_hw *ah, unsigned int usec)
+{
+        return usec * ath5k_hw_get_clockrate(ah);
+}
+
+/**
+ * ath5k_hw_clocktoh - Translate hw clock units to usec
+ * @clock: value in hw clock units
+ */
+unsigned int ath5k_hw_clocktoh(struct ath5k_hw *ah, unsigned int clock)
+{
+        return clock / ath5k_hw_get_clockrate(ah);
+}
+
+/**
+ * ath5k_hw_get_clockrate - Get the clock rate for current mode
+ *
+ * @ah: The &struct ath5k_hw
+ */
+unsigned int ath5k_hw_get_clockrate(struct ath5k_hw *ah)
+{
+        struct ieee80211_channel *channel = ah->ah_current_channel;
+        int clock;
+
+        if (channel->hw_value & CHANNEL_5GHZ)
+                clock = 40; /* 802.11a */
+        else if (channel->hw_value & CHANNEL_CCK)
+                clock = 22; /* 802.11b */
+        else
+                clock = 44; /* 802.11g */
+
+        /* Clock rate in turbo modes is twice the normal rate */
+        if (channel->hw_value & CHANNEL_TURBO)
+                clock *= 2;
+
+        return clock;
+}
+
+/**
  * ath5k_hw_set_lladdr - Set station id
  *
  * @ah: The &struct ath5k_hw