3 files changed, 58 insertions, 1 deletions

diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index fb877b5621b7..17c5c8849250 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -804,6 +804,28 @@ enum nl80211_commands {
  * @NL80211_ATTR_SUPPORT_IBSS_RSN: The device supports IBSS RSN, which mostly
  *      means support for per-station GTKs.
  *
+ * @NL80211_ATTR_WIPHY_ANTENNA_TX: Bitmap of allowed antennas for transmitting.
+ *      This can be used to mask out antennas which are not attached or should
+ *      not be used for transmitting. If an antenna is not selected in this
+ *      bitmap the hardware is not allowed to transmit on this antenna.
+ *
+ *      Each bit represents one antenna, starting with antenna 1 at the first
+ *      bit. Depending on which antennas are selected in the bitmap, 802.11n
+ *      drivers can derive which chainmasks to use (if all antennas belonging to
+ *      a particular chain are disabled this chain should be disabled) and if
+ *      a chain has diversity antennas wether diversity should be used or not.
+ *      HT capabilities (STBC, TX Beamforming, Antenna selection) can be
+ *      derived from the available chains after applying the antenna mask.
+ *      Non-802.11n drivers can derive wether to use diversity or not.
+ *      Drivers may reject configurations or RX/TX mask combinations they cannot
+ *      support by returning -EINVAL.
+ *
+ * @NL80211_ATTR_WIPHY_ANTENNA_RX: Bitmap of allowed antennas for receiving.
+ *      This can be used to mask out antennas which are not attached or should
+ *      not be used for receiving. If an antenna is not selected in this bitmap
+ *      the hardware should not be configured to receive on this antenna.
+ *      For a more detailed descripton see @NL80211_ATTR_WIPHY_ANTENNA_TX.
+ *
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
  */
@@ -973,6 +995,9 @@ enum nl80211_attrs {
 
         NL80211_ATTR_SUPPORT_IBSS_RSN,
 
+        NL80211_ATTR_WIPHY_ANTENNA_TX,
+        NL80211_ATTR_WIPHY_ANTENNA_RX,
+
         /* add attributes here, update the policy in nl80211.c */
 
         __NL80211_ATTR_AFTER_LAST,
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index e5702f5ac57c..07425e648a09 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1304,6 +1304,9 @@ struct cfg80211_ops {
         void    (*mgmt_frame_register)(struct wiphy *wiphy,
                                        struct net_device *dev,
                                        u16 frame_type, bool reg);
+
+        int     (*set_antenna)(struct wiphy *wiphy, u32 tx_ant, u32 rx_ant);
+        int     (*get_antenna)(struct wiphy *wiphy, u32 *tx_ant, u32 *rx_ant);
 };
 
 /*
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index c506241f8637..5e4dda4c0fd3 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -166,7 +166,11 @@ static const struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] = {
 
         [NL80211_ATTR_WIPHY_TX_POWER_SETTING] = { .type = NLA_U32 },
         [NL80211_ATTR_WIPHY_TX_POWER_LEVEL] = { .type = NLA_U32 },
+
         [NL80211_ATTR_FRAME_TYPE] = { .type = NLA_U16 },
+
+        [NL80211_ATTR_WIPHY_ANTENNA_TX] = { .type = NLA_U32 },
+        [NL80211_ATTR_WIPHY_ANTENNA_RX] = { .type = NLA_U32 },
 };
 
 /* policy for the key attributes */
@@ -526,7 +530,6 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
                     dev->wiphy.rts_threshold);
         NLA_PUT_U8(msg, NL80211_ATTR_WIPHY_COVERAGE_CLASS,
                     dev->wiphy.coverage_class);
-
         NLA_PUT_U8(msg, NL80211_ATTR_MAX_NUM_SCAN_SSIDS,
                    dev->wiphy.max_scan_ssids);
         NLA_PUT_U16(msg, NL80211_ATTR_MAX_SCAN_IE_LEN,
@@ -545,6 +548,16 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
         if (dev->wiphy.flags & WIPHY_FLAG_CONTROL_PORT_PROTOCOL)
                 NLA_PUT_FLAG(msg, NL80211_ATTR_CONTROL_PORT_ETHERTYPE);
 
+        if (dev->ops->get_antenna) {
+                u32 tx_ant = 0, rx_ant = 0;
+                int res;
+                res = dev->ops->get_antenna(&dev->wiphy, &tx_ant, &rx_ant);
+                if (!res) {
+                        NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_ANTENNA_TX, tx_ant);
+                        NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_ANTENNA_RX, rx_ant);
+                }
+        }
+
         nl_modes = nla_nest_start(msg, NL80211_ATTR_SUPPORTED_IFTYPES);
         if (!nl_modes)
                 goto nla_put_failure;
@@ -1024,6 +1037,22 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
                         goto bad_res;
         }
 
+        if (info->attrs[NL80211_ATTR_WIPHY_ANTENNA_TX] &&
+            info->attrs[NL80211_ATTR_WIPHY_ANTENNA_RX]) {
+                u32 tx_ant, rx_ant;
+                if (!rdev->ops->set_antenna) {
+                        result = -EOPNOTSUPP;
+                        goto bad_res;
+                }
+
+                tx_ant = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_ANTENNA_TX]);
+                rx_ant = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_ANTENNA_RX]);
+
+                result = rdev->ops->set_antenna(&rdev->wiphy, tx_ant, rx_ant);
+                if (result)
+                        goto bad_res;
+        }
+
         changed = 0;
 
         if (info->attrs[NL80211_ATTR_WIPHY_RETRY_SHORT]) {