rsi: add support for hardware scan offload

With the current approach of scanning, roaming delays are observed.
Firmware has support for back ground scanning. To get this advantage,
mac80211 hardware scan is implemented, which decides type of scan to
do based on connected state.

When station is in not connected, driver returns with special value 1
to trigger software scan in mac80211. In case of connected state,
background scan will be triggered.

Signed-off-by: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>
Signed-off-by: Siva Rebbagondla <siva.rebbagondla@redpinesignals.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

1 files changed, 67 insertions, 0 deletions

diff --git a/drivers/net/wireless/rsi/rsi_91x_mac80211.c b/drivers/net/wireless/rsi/rsi_91x_mac80211.c
index e56fc83faf0e..aded1ae4fad5 100644
--- a/drivers/net/wireless/rsi/rsi_91x_mac80211.c
+++ b/drivers/net/wireless/rsi/rsi_91x_mac80211.c
@@ -229,6 +229,68 @@ static void rsi_register_rates_channels(struct rsi_hw *adapter, int band)
 	/* sbands->ht_cap.mcs.rx_highest = 0x82; */
 }
 
+static int rsi_mac80211_hw_scan_start(struct ieee80211_hw *hw,
+				      struct ieee80211_vif *vif,
+				      struct ieee80211_scan_request *hw_req)
+{
+	struct cfg80211_scan_request *scan_req = &hw_req->req;
+	struct rsi_hw *adapter = hw->priv;
+	struct rsi_common *common = adapter->priv;
+	struct ieee80211_bss_conf *bss = &vif->bss_conf;
+
+	rsi_dbg(INFO_ZONE, "***** Hardware scan start *****\n");
+
+	if (common->fsm_state != FSM_MAC_INIT_DONE)
+		return -ENODEV;
+
+	if ((common->wow_flags & RSI_WOW_ENABLED) ||
+	    scan_req->n_channels == 0)
+		return -EINVAL;
+
+	/* Scan already in progress. So return */
+	if (common->bgscan_en)
+		return -EBUSY;
+
+	/* If STA is not connected, return with special value 1, in order
+	 * to start sw_scan in mac80211
+	 */
+	if (!bss->assoc)
+		return 1;
+
+	mutex_lock(&common->mutex);
+	common->hwscan = scan_req;
+	if (!rsi_send_bgscan_params(common, RSI_START_BGSCAN)) {
+		if (!rsi_send_bgscan_probe_req(common, vif)) {
+			rsi_dbg(INFO_ZONE, "Background scan started...\n");
+			common->bgscan_en = true;
+		}
+	}
+	mutex_unlock(&common->mutex);
+
+	return 0;
+}
+
+static void rsi_mac80211_cancel_hw_scan(struct ieee80211_hw *hw,
+					struct ieee80211_vif *vif)
+{
+	struct rsi_hw *adapter = hw->priv;
+	struct rsi_common *common = adapter->priv;
+	struct cfg80211_scan_info info;
+
+	rsi_dbg(INFO_ZONE, "***** Hardware scan stop *****\n");
+	mutex_lock(&common->mutex);
+
+	if (common->bgscan_en) {
+		if (!rsi_send_bgscan_params(common, RSI_STOP_BGSCAN))
+			common->bgscan_en = false;
+		info.aborted = false;
+		ieee80211_scan_completed(adapter->hw, &info);
+		rsi_dbg(INFO_ZONE, "Back ground scan cancelled\b\n");
+	}
+	common->hwscan = NULL;
+	mutex_unlock(&common->mutex);
+}
+
 /**
  * rsi_mac80211_detach() - This function is used to de-initialize the
  *			   Mac80211 stack.
@@ -1917,6 +1979,8 @@ static const struct ieee80211_ops mac80211_ops = {
 	.suspend = rsi_mac80211_suspend,
 	.resume  = rsi_mac80211_resume,
 #endif
+	.hw_scan = rsi_mac80211_hw_scan_start,
+	.cancel_hw_scan = rsi_mac80211_cancel_hw_scan,
 };
 
 /**
@@ -1999,6 +2063,9 @@ int rsi_mac80211_attach(struct rsi_common *common)
 	common->max_stations = wiphy->max_ap_assoc_sta;
 	rsi_dbg(ERR_ZONE, "Max Stations Allowed = %d\n", common->max_stations);
 	hw->sta_data_size = sizeof(struct rsi_sta);
+
+	wiphy->max_scan_ssids = RSI_MAX_SCAN_SSIDS;
+	wiphy->max_scan_ie_len = RSI_MAX_SCAN_IE_LEN;
 	wiphy->flags = WIPHY_FLAG_REPORTS_OBSS;
 	wiphy->flags |= WIPHY_FLAG_AP_UAPSD;
 	wiphy->features |= NL80211_FEATURE_INACTIVITY_TIMER;