I see, we could add helper function that will calculate
center_freq/bandwidth, but starting from defining new channel
structure and accompanying code in nl80211/mac80211 is more
reasonable.

Stanislaw

How about below new channel config structure? wanted to fit 80+80 config 
as well.

/**
  * enum ieee80211_chan_width - channel bandwidths
  *
  * @IEEE80211_CHAN_WIDTH_20MHZ: 20 MHz chan bandwidth
  * @IEEE80211_CHAN_WIDTH_40MHZ: 40 MHz chan bandwidth
  * @IEEE80211_CHAN_WIDTH_80MHZ: 80 MHz chan bandwidth
  * @IEEE80211_CHAN_WIDTH_160MHZ: 160 MHz chan bandwidth
  */
enum ieee80211_chan_width {
         IEEE80211_CHAN_WIDTH_20MHZ = 20,
         IEEE80211_CHAN_WIDTH_40MHZ = 40,
         IEEE80211_CHAN_WIDTH_80MHZ = 80,
         IEEE80211_CHAN_WIDTH_160MHZ = 160
};

/**
  * struct ieee80211_channel_config - channel config definition
  *
  * This structure describes channel configuration
  *
  * @chan_width1: channel bandwidth 1
  * @center_freq1: center frequency 1 for entire chan width
  * @control_offset1: control chan offset 1
  * @chan_width2: channel bandwidth 2
  * @center_freq2: center frequency 2 for entire chan width
  * @control_offset2: control chan offset 2
  */
struct ieee80211_channel_config {
         enum ieee80211_chan_width chan_width1;
         u16 center_freq1;
         u16 control_offset1;
         enum ieee80211_chan_width chan_width2;
         u16 center_freq2;
         u16 control_offset2;
};