iwlwifi: support channel switch offload in driver

Support channel switch in driver as a separated mac80211 callback
function instead of part of mac_config callback; by moving to this
approach, uCode can have more control of channel switch timing.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>

1 files changed, 44 insertions, 9 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-6000.c b/drivers/net/wireless/iwlwifi/iwl-6000.c
index 5f6dbd9561d..077514546d0 100644
--- a/drivers/net/wireless/iwlwifi/iwl-6000.c
+++ b/drivers/net/wireless/iwlwifi/iwl-6000.c
@@ -239,10 +239,17 @@ static int iwl6050_hw_set_hw_params(struct iwl_priv *priv)
 	return 0;
 }
 
-static int iwl6000_hw_channel_switch(struct iwl_priv *priv, u16 channel)
+static int iwl6000_hw_channel_switch(struct iwl_priv *priv,
+				     struct ieee80211_channel_switch *ch_switch)
 {
 	struct iwl6000_channel_switch_cmd cmd;
 	const struct iwl_channel_info *ch_info;
+	u32 switch_time_in_usec, ucode_switch_time;
+	u16 ch;
+	u32 tsf_low;
+	u8 switch_count;
+	u16 beacon_interval = le16_to_cpu(priv->rxon_timing.beacon_interval);
+	struct ieee80211_vif *vif = priv->vif;
 	struct iwl_host_cmd hcmd = {
 		.id = REPLY_CHANNEL_SWITCH,
 		.len = sizeof(cmd),
@@ -250,23 +257,51 @@ static int iwl6000_hw_channel_switch(struct iwl_priv *priv, u16 channel)
 		.data = &cmd,
 	};
 
-	IWL_DEBUG_11H(priv, "channel switch from %d to %d\n",
-		priv->active_rxon.channel, channel);
-
 	cmd.band = priv->band == IEEE80211_BAND_2GHZ;
-	cmd.channel = cpu_to_le16(channel);
+	ch = ieee80211_frequency_to_channel(ch_switch->channel->center_freq);
+	IWL_DEBUG_11H(priv, "channel switch from %u to %u\n",
+		      priv->active_rxon.channel, ch);
+	cmd.channel = cpu_to_le16(ch);
 	cmd.rxon_flags = priv->staging_rxon.flags;
 	cmd.rxon_filter_flags = priv->staging_rxon.filter_flags;
-	cmd.switch_time = cpu_to_le32(priv->ucode_beacon_time);
-	ch_info = iwl_get_channel_info(priv, priv->band, channel);
+	switch_count = ch_switch->count;
+	tsf_low = ch_switch->timestamp & 0x0ffffffff;
+	/*
+	 * calculate the ucode channel switch time
+	 * adding TSF as one of the factor for when to switch
+	 */
+	if ((priv->ucode_beacon_time > tsf_low) && beacon_interval) {
+		if (switch_count > ((priv->ucode_beacon_time - tsf_low) /
+		    beacon_interval)) {
+			switch_count -= (priv->ucode_beacon_time -
+				tsf_low) / beacon_interval;
+		} else
+			switch_count = 0;
+	}
+	if (switch_count <= 1)
+		cmd.switch_time = cpu_to_le32(priv->ucode_beacon_time);
+	else {
+		switch_time_in_usec =
+			vif->bss_conf.beacon_int * switch_count * TIME_UNIT;
+		ucode_switch_time = iwl_usecs_to_beacons(priv,
+							 switch_time_in_usec,
+							 beacon_interval);
+		cmd.switch_time = iwl_add_beacon_time(priv,
+						      priv->ucode_beacon_time,
+						      ucode_switch_time,
+						      beacon_interval);
+	}
+	IWL_DEBUG_11H(priv, "uCode time for the switch is 0x%x\n",
+		      cmd.switch_time);
+	ch_info = iwl_get_channel_info(priv, priv->band, ch);
 	if (ch_info)
 		cmd.expect_beacon = is_channel_radar(ch_info);
 	else {
 		IWL_ERR(priv, "invalid channel switch from %u to %u\n",
-			priv->active_rxon.channel, channel);
+			priv->active_rxon.channel, ch);
 		return -EFAULT;
 	}
-	priv->switch_rxon.channel = cpu_to_le16(channel);
+	priv->switch_rxon.channel = cmd.channel;
 	priv->switch_rxon.switch_in_progress = true;
 
 	return iwl_send_cmd_sync(priv, &hcmd);