[PATCH] cfg80211: Add new helper function for channels

[Amar Singhal <asinghal@xxxxxxxxxxxxxx>]

Add new helper function to convert (chan_number, oper_class) pair to
frequency. Call this function ieee80211_channel_op_class_to_frequency.
This function would be very useful in the context of 6 GHz channels,
where channel number is not unique.

Signed-off-by: Amar Singhal <asinghal@xxxxxxxxxxxxxx>
---
 include/net/cfg80211.h | 10 ++++++++++
 net/wireless/util.c    | 23 +++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 6467b60..decafba 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -4914,1 +4914,1 @@ static inline void *wdev_priv(struct wireless_dev *wdev)
 int ieee80211_channel_to_frequency(int chan, enum nl80211_band band);

 /**
+ * ieee80211_channel_op_class_to_frequency - convert
+ * (channel, operating class) to frequency
+ * @chan_num: channel number
+ * @global_op_class: global operating class
+ *
+ * Return: The corresponding frequency, or 0 if the conversion failed.
+ */
+int ieee80211_channel_op_class_to_frequency(u8 chan_num, u8 global_op_class);
+
+/**
  * ieee80211_frequency_to_channel - convert frequency to channel number
  * @freq: center frequency
  * Return: The corresponding channel, or 0 if the conversion failed.
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 9aba8d54..7f64b4a 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -144,6 +144,29 @@ struct ieee80211_channel *ieee80211_get_channel(struct wiphy *wiphy, int freq)
 }
 EXPORT_SYMBOL(ieee80211_get_channel);

+int ieee80211_channel_op_class_to_frequency(u8 chan_num, u8 global_op_class)
+{
+	if (global_op_class >= 131 && global_op_class <= 135)
+		return (5940 + 5 * chan_num);
+	else if (global_op_class >= 115 && global_op_class <= 130)
+		return (5000 + 5 * chan_num);
+	else if (global_op_class >= 112 && global_op_class <= 113)
+		return (5000 + 5 * chan_num);
+	else if (global_op_class >= 109 && global_op_class <= 110)
+		return (4000 + 5 * chan_num);
+	else if (global_op_class >= 83 && global_op_class <= 84)
+		return (2407 + 5 * chan_num);
+	else if (global_op_class == 81)
+		return (2407 + 5 * chan_num);
+	else if (global_op_class == 82)
+		return (2414 + 5 * chan_num);
+	else if (global_op_class == 180)
+		return (56160 + 5 * chan_num);
+	else
+		return 0;
+}
+EXPORT_SYMBOL(ieee80211_channel_op_class_to_frequency);
+
 static void set_mandatory_flags_band(struct ieee80211_supported_band *sband)
 {
 	int i, want;
--
1.9.1