iwlwifi: mvm: Enable user set TX power

Support Tx power limitations. These limitations can come from
mac80211 for various reasons.

Signed-off-by: Matti Gottlieb <matti.gottlieb@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
index 30319e0..fbb8c2d 100644
--- a/drivers/net/wireless/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
@@ -714,6 +714,20 @@
 	mutex_unlock(&mvm->mutex);
 }
 
+static int iwl_mvm_set_tx_power(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
+				s8 tx_power)
+{
+	/* FW is in charge of regulatory enforcement */
+	struct iwl_reduce_tx_power_cmd reduce_txpwr_cmd = {
+		.mac_context_id = iwl_mvm_vif_from_mac80211(vif)->id,
+		.pwr_restriction = cpu_to_le16(tx_power),
+	};
+
+	return iwl_mvm_send_cmd_pdu(mvm, REDUCE_TX_POWER_CMD, CMD_SYNC,
+				    sizeof(reduce_txpwr_cmd),
+				    &reduce_txpwr_cmd);
+}
+
 static int iwl_mvm_mac_config(struct ieee80211_hw *hw, u32 changed)
 {
 	return 0;
@@ -794,6 +808,11 @@
 		if (ret)
 			IWL_ERR(mvm, "failed to update power mode\n");
 	}
+	if (changes & BSS_CHANGED_TXPOWER) {
+		IWL_DEBUG_CALIB(mvm, "Changing TX Power to %d\n",
+				bss_conf->txpower);
+		iwl_mvm_set_tx_power(mvm, vif, bss_conf->txpower);
+	}
 }
 
 static int iwl_mvm_start_ap(struct ieee80211_hw *hw, struct ieee80211_vif *vif)