{cfg,mac}80211: move mandatory rates calculation to cfg80211

Move mandatory rates calculation to cfg80211, shared with non mac80211 drivers.

Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
[extend documentation]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/net/wireless/util.c b/net/wireless/util.c
index b11052be09be..0962f107f57f 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -33,6 +33,29 @@ ieee80211_get_response_rate(struct ieee80211_supported_band *sband,
 }
 EXPORT_SYMBOL(ieee80211_get_response_rate);
 
+u32 ieee80211_mandatory_rates(struct ieee80211_supported_band *sband)
+{
+        struct ieee80211_rate *bitrates;
+        u32 mandatory_rates = 0;
+        enum ieee80211_rate_flags mandatory_flag;
+        int i;
+
+        if (WARN_ON(!sband))
+                return 1;
+
+        if (sband->band == IEEE80211_BAND_2GHZ)
+                mandatory_flag = IEEE80211_RATE_MANDATORY_B;
+        else
+                mandatory_flag = IEEE80211_RATE_MANDATORY_A;
+
+        bitrates = sband->bitrates;
+        for (i = 0; i < sband->n_bitrates; i++)
+                if (bitrates[i].flags & mandatory_flag)
+                        mandatory_rates |= BIT(i);
+        return mandatory_rates;
+}
+EXPORT_SYMBOL(ieee80211_mandatory_rates);
+
 int ieee80211_channel_to_frequency(int chan, enum ieee80211_band band)
 {
         /* see 802.11 17.3.8.3.2 and Annex J