rt2x00: Implement get_survey callback for rt2800

Implement the get_survey callback to allow user space to read statistics
about the current channel condition.
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2800.h

@@ -699,8 +699,18 @@
 
 /*
  * CH_TIME_CFG: count as channel busy
+ * EIFS_BUSY: Count EIFS as channel busy
+ * NAV_BUSY: Count NAS as channel busy
+ * RX_BUSY: Count RX as channel busy
+ * TX_BUSY: Count TX as channel busy
+ * TMR_EN: Enable channel statistics timer
  */
 #define CH_TIME_CFG     	        0x110c
+#define CH_TIME_CFG_EIFS_BUSY		FIELD32(0x00000010)
+#define CH_TIME_CFG_NAV_BUSY		FIELD32(0x00000008)
+#define CH_TIME_CFG_RX_BUSY		FIELD32(0x00000004)
+#define CH_TIME_CFG_TX_BUSY		FIELD32(0x00000002)
+#define CH_TIME_CFG_TMR_EN		FIELD32(0x00000001)
 
 /*
  * PBF_LIFE_TIMER: TX/RX MPDU timestamp timer (free run) Unit: 1us

drivers/net/wireless/rt2x00/rt2800lib.c

@@ -1625,6 +1625,13 @@ static void rt2800_config_channel(struct rt2x00_dev *rt2x00dev,
 	}
 
 	msleep(1);
+
+	/*
+	 * Clear channel statistic counters
+	 */
+	rt2800_register_read(rt2x00dev, CH_IDLE_STA, &reg);
+	rt2800_register_read(rt2x00dev, CH_BUSY_STA, &reg);
+	rt2800_register_read(rt2x00dev, CH_BUSY_STA_SEC, &reg);
 }
 
 static void rt2800_config_txpower(struct rt2x00_dev *rt2x00dev,
@@ -2259,6 +2266,17 @@ static int rt2800_init_registers(struct rt2x00_dev *rt2x00dev)
 	rt2x00_set_field32(&reg, INT_TIMER_CFG_PRE_TBTT_TIMER, 6 << 4);
 	rt2800_register_write(rt2x00dev, INT_TIMER_CFG, reg);
 
+	/*
+	 * Set up channel statistics timer
+	 */
+	rt2800_register_read(rt2x00dev, CH_TIME_CFG, &reg);
+	rt2x00_set_field32(&reg, CH_TIME_CFG_EIFS_BUSY, 1);
+	rt2x00_set_field32(&reg, CH_TIME_CFG_NAV_BUSY, 1);
+	rt2x00_set_field32(&reg, CH_TIME_CFG_RX_BUSY, 1);
+	rt2x00_set_field32(&reg, CH_TIME_CFG_TX_BUSY, 1);
+	rt2x00_set_field32(&reg, CH_TIME_CFG_TMR_EN, 1);
+	rt2800_register_write(rt2x00dev, CH_TIME_CFG, reg);
+
 	return 0;
 }
 
@@ -3539,6 +3557,37 @@ int rt2800_ampdu_action(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 }
 EXPORT_SYMBOL_GPL(rt2800_ampdu_action);
 
+int rt2800_get_survey(struct ieee80211_hw *hw, int idx,
+		      struct survey_info *survey)
+{
+	struct rt2x00_dev *rt2x00dev = hw->priv;
+	struct ieee80211_conf *conf = &hw->conf;
+	u32 idle, busy, busy_ext;
+
+	if (idx != 0)
+		return -ENOENT;
+
+	survey->channel = conf->channel;
+
+	rt2800_register_read(rt2x00dev, CH_IDLE_STA, &idle);
+	rt2800_register_read(rt2x00dev, CH_BUSY_STA, &busy);
+	rt2800_register_read(rt2x00dev, CH_BUSY_STA_SEC, &busy_ext);
+
+	if (idle || busy) {
+		survey->filled = SURVEY_INFO_CHANNEL_TIME |
+				 SURVEY_INFO_CHANNEL_TIME_BUSY |
+				 SURVEY_INFO_CHANNEL_TIME_EXT_BUSY;
+
+		survey->channel_time = (idle + busy) / 1000;
+		survey->channel_time_busy = busy / 1000;
+		survey->channel_time_ext_busy = busy_ext / 1000;
+	}
+
+	return 0;
+
+}
+EXPORT_SYMBOL_GPL(rt2800_get_survey);
+
 MODULE_AUTHOR(DRV_PROJECT ", Bartlomiej Zolnierkiewicz");
 MODULE_VERSION(DRV_VERSION);
 MODULE_DESCRIPTION("Ralink RT2800 library");

drivers/net/wireless/rt2x00/rt2800lib.h

@@ -199,5 +199,7 @@ u64 rt2800_get_tsf(struct ieee80211_hw *hw);
 int rt2800_ampdu_action(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			enum ieee80211_ampdu_mlme_action action,
 			struct ieee80211_sta *sta, u16 tid, u16 *ssn);
+int rt2800_get_survey(struct ieee80211_hw *hw, int idx,
+		      struct survey_info *survey);
 
 #endif /* RT2800LIB_H */

drivers/net/wireless/rt2x00/rt2800pci.c

@@ -944,6 +944,7 @@ static const struct ieee80211_ops rt2800pci_mac80211_ops = {
 	.rfkill_poll		= rt2x00mac_rfkill_poll,
 	.ampdu_action		= rt2800_ampdu_action,
 	.flush			= rt2x00mac_flush,
+	.get_survey		= rt2800_get_survey,
 };
 
 static const struct rt2800_ops rt2800pci_rt2800_ops = {

drivers/net/wireless/rt2x00/rt2800usb.c

@@ -562,6 +562,7 @@ static const struct ieee80211_ops rt2800usb_mac80211_ops = {
 	.rfkill_poll		= rt2x00mac_rfkill_poll,
 	.ampdu_action		= rt2800_ampdu_action,
 	.flush			= rt2x00mac_flush,
+	.get_survey		= rt2800_get_survey,
 };
 
 static const struct rt2800_ops rt2800usb_rt2800_ops = {