[MAC80211]: Add support for setting TX power and radio status

This adds support for disabling the radio and setting the TXpower
through wext.
This also fixes the prism TXpower ioctl (It always overwrote the TXpower
value in ieee80211_hw_config())
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mac80211/ieee80211.c

@@ -704,7 +704,12 @@ int ieee80211_hw_config(struct ieee80211_local *local)
 
 	local->hw.conf.channel = chan->chan;
 	local->hw.conf.channel_val = chan->val;
+	if (!local->hw.conf.power_level) {
 		local->hw.conf.power_level = chan->power_level;
+	} else {
+		local->hw.conf.power_level = min(chan->power_level,
+						 local->hw.conf.power_level);
+	}
 	local->hw.conf.freq = chan->freq;
 	local->hw.conf.phymode = mode->mode;
 	local->hw.conf.antenna_max = chan->antenna_max;

net/mac80211/ieee80211_ioctl.c

@@ -666,6 +666,38 @@ static int ieee80211_ioctl_giwrate(struct net_device *dev,
 	return 0;
 }
 
+static int ieee80211_ioctl_siwtxpower(struct net_device *dev,
+				      struct iw_request_info *info,
+				      union iwreq_data *data, char *extra)
+{
+	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+	bool need_reconfig = 0;
+
+	if ((data->txpower.flags & IW_TXPOW_TYPE) != IW_TXPOW_DBM)
+		return -EINVAL;
+	if (data->txpower.flags & IW_TXPOW_RANGE)
+		return -EINVAL;
+	if (!data->txpower.fixed)
+		return -EINVAL;
+
+	if (local->hw.conf.power_level != data->txpower.value) {
+		local->hw.conf.power_level = data->txpower.value;
+		need_reconfig = 1;
+	}
+	if (local->hw.conf.radio_enabled != !(data->txpower.disabled)) {
+		local->hw.conf.radio_enabled = !(data->txpower.disabled);
+		need_reconfig = 1;
+	}
+	if (need_reconfig) {
+		ieee80211_hw_config(local);
+		/* The return value of hw_config is not of big interest here,
+		 * as it doesn't say that it failed because of _this_ config
+		 * change or something else. Ignore it. */
+	}
+
+	return 0;
+}
+
 static int ieee80211_ioctl_giwtxpower(struct net_device *dev,
 				   struct iw_request_info *info,
 				   union iwreq_data *data, char *extra)
@@ -1339,7 +1371,7 @@ static const iw_handler ieee80211_handler[] =
 	(iw_handler) ieee80211_ioctl_giwrts,		/* SIOCGIWRTS */
 	(iw_handler) ieee80211_ioctl_siwfrag,		/* SIOCSIWFRAG */
 	(iw_handler) ieee80211_ioctl_giwfrag,		/* SIOCGIWFRAG */
-	(iw_handler) NULL,				/* SIOCSIWTXPOW */
+	(iw_handler) ieee80211_ioctl_siwtxpower,	/* SIOCSIWTXPOW */
 	(iw_handler) ieee80211_ioctl_giwtxpower,	/* SIOCGIWTXPOW */
 	(iw_handler) ieee80211_ioctl_siwretry,		/* SIOCSIWRETRY */
 	(iw_handler) ieee80211_ioctl_giwretry,		/* SIOCGIWRETRY */