libertas: add an cfg80211 interface for powersaving

This patch adds an interface for handling commands like
iwconfig wlanX power on/off. Such an interface formerly existed
when the driver used wext.

While performance with sdio in polling mode without using
powersave mode is quite bad, powersaving mode is unusable,
so do not enable it under such conditions.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/marvell/libertas/cfg.c

@@ -2039,6 +2039,43 @@ static int lbs_leave_ibss(struct wiphy *wiphy, struct net_device *dev)
 
 
 
+int lbs_set_power_mgmt(struct wiphy *wiphy, struct net_device *dev,
+		       bool enabled, int timeout)
+{
+	struct lbs_private *priv = wiphy_priv(wiphy);
+
+	if  (!(priv->fwcapinfo & FW_CAPINFO_PS)) {
+		if (!enabled)
+			return 0;
+		else
+			return -EINVAL;
+	}
+	/* firmware does not work well with too long latency with power saving
+	 * enabled, so do not enable it if there is only polling, no
+	 * interrupts (like in some sdio hosts which can only
+	 * poll for sdio irqs)
+	 */
+	if  (priv->is_polling) {
+		if (!enabled)
+			return 0;
+		else
+			return -EINVAL;
+	}
+	if (!enabled) {
+		priv->psmode = LBS802_11POWERMODECAM;
+		if (priv->psstate != PS_STATE_FULL_POWER)
+			lbs_set_ps_mode(priv,
+					PS_MODE_ACTION_EXIT_PS,
+					true);
+		return 0;
+	}
+	if (priv->psmode != LBS802_11POWERMODECAM)
+		return 0;
+	priv->psmode = LBS802_11POWERMODEMAX_PSP;
+	if (priv->connect_status == LBS_CONNECTED)
+		lbs_set_ps_mode(priv, PS_MODE_ACTION_ENTER_PS, true);
+	return 0;
+}
 
 /*
  * Initialization
@@ -2057,6 +2094,7 @@ static struct cfg80211_ops lbs_cfg80211_ops = {
 	.change_virtual_intf = lbs_change_intf,
 	.join_ibss = lbs_join_ibss,
 	.leave_ibss = lbs_leave_ibss,
+	.set_power_mgmt = lbs_set_power_mgmt,
 };