rt2x00: Implement Powersaving

Listen to IEEE80211_CONF_PS to determine if the device
should drop into powersaving mode. This feature depends
on the dynamic power save functionality in mac80211.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt73usb.c b/drivers/net/wireless/rt2x00/rt73usb.c
index 96a8d69..ae3b31d 100644
--- a/drivers/net/wireless/rt2x00/rt73usb.c
+++ b/drivers/net/wireless/rt2x00/rt73usb.c
@@ -844,6 +844,44 @@
 	rt2x00usb_register_write(rt2x00dev, TXRX_CSR9, reg);
 }
 
+static void rt73usb_config_ps(struct rt2x00_dev *rt2x00dev,
+				struct rt2x00lib_conf *libconf)
+{
+	enum dev_state state =
+	    (libconf->conf->flags & IEEE80211_CONF_PS) ?
+		STATE_SLEEP : STATE_AWAKE;
+	u32 reg;
+
+	if (state == STATE_SLEEP) {
+		rt2x00usb_register_read(rt2x00dev, MAC_CSR11, &reg);
+		rt2x00_set_field32(&reg, MAC_CSR11_DELAY_AFTER_TBCN,
+				   libconf->conf->beacon_int - 10);
+		rt2x00_set_field32(&reg, MAC_CSR11_TBCN_BEFORE_WAKEUP,
+				   libconf->conf->listen_interval - 1);
+		rt2x00_set_field32(&reg, MAC_CSR11_WAKEUP_LATENCY, 5);
+
+		/* We must first disable autowake before it can be enabled */
+		rt2x00_set_field32(&reg, MAC_CSR11_AUTOWAKE, 0);
+		rt2x00usb_register_write(rt2x00dev, MAC_CSR11, reg);
+
+		rt2x00_set_field32(&reg, MAC_CSR11_AUTOWAKE, 1);
+		rt2x00usb_register_write(rt2x00dev, MAC_CSR11, reg);
+
+		rt2x00usb_vendor_request_sw(rt2x00dev, USB_DEVICE_MODE, 0,
+					    USB_MODE_SLEEP, REGISTER_TIMEOUT);
+	} else {
+		rt2x00usb_vendor_request_sw(rt2x00dev, USB_DEVICE_MODE, 0,
+					    USB_MODE_WAKEUP, REGISTER_TIMEOUT);
+
+		rt2x00usb_register_read(rt2x00dev, MAC_CSR11, &reg);
+		rt2x00_set_field32(&reg, MAC_CSR11_DELAY_AFTER_TBCN, 0);
+		rt2x00_set_field32(&reg, MAC_CSR11_TBCN_BEFORE_WAKEUP, 0);
+		rt2x00_set_field32(&reg, MAC_CSR11_AUTOWAKE, 0);
+		rt2x00_set_field32(&reg, MAC_CSR11_WAKEUP_LATENCY, 0);
+		rt2x00usb_register_write(rt2x00dev, MAC_CSR11, reg);
+	}
+}
+
 static void rt73usb_config(struct rt2x00_dev *rt2x00dev,
 			   struct rt2x00lib_conf *libconf,
 			   const unsigned int flags)
@@ -861,6 +899,8 @@
 		rt73usb_config_retry_limit(rt2x00dev, libconf);
 	if (flags & IEEE80211_CONF_CHANGE_BEACON_INTERVAL)
 		rt73usb_config_duration(rt2x00dev, libconf);
+	if (flags & IEEE80211_CONF_CHANGE_PS)
+		rt73usb_config_ps(rt2x00dev, libconf);
 }
 
 /*