[PATCH v2] ath10k: add support for controlling tx power to a station

[Ashok Raj Nagarajan]

This patch will add the support to control the transmit power for traffic
to a station associated with the AP. Userspace provide the transmit power
value in mBm units and the allowed range is from 0 to 70. Underlying FW
will enforce that the maximum tx power will be based on the regulatory
requirements. If the user given transmit power is greater than the allowed
tx power in the given channel, then the FW will use the maximum tx power
in the same channel.

When 0 is sent to the FW as tx power, it will revert to the automatic tx
power for the station.

Signed-off-by: Ashok Raj Nagarajan <arnagara at qti.qualcomm.com>
---
v2:
	- indicate that the driver supports this feature using
	  NL80211_EXT_FEATURE_STA_TX_PWR

 drivers/net/wireless/ath/ath10k/debug.h |  3 +++
 drivers/net/wireless/ath/ath10k/mac.c   | 33 +++++++++++++++++++++++++++++++++
 drivers/net/wireless/ath/ath10k/wmi.h   |  1 +
 3 files changed, 37 insertions(+)

diff --git a/drivers/net/wireless/ath/ath10k/debug.h b/drivers/net/wireless/ath/ath10k/debug.h
index 2368f47..db51453 100644
--- a/drivers/net/wireless/ath/ath10k/debug.h
+++ b/drivers/net/wireless/ath/ath10k/debug.h
@@ -59,6 +59,9 @@ enum ath10k_dbg_aggr_mode {
 /* FIXME: How to calculate the buffer size sanely? */
 #define ATH10K_FW_STATS_BUF_SIZE (1024 * 1024)
 
+#define ATH10K_TX_POWER_MAX_VAL 70
+#define ATH10K_TX_POWER_MIN_VAL 0
+
 extern unsigned int ath10k_debug_mask;
 
 __printf(2, 3) void ath10k_info(struct ath10k *ar, const char *fmt, ...);
diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index 9977829..d1a5937 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -5985,6 +5985,34 @@ static int ath10k_mac_tdls_vifs_count(struct ieee80211_hw *hw)
 	return num_tdls_vifs;
 }
 
+static int ath10k_sta_set_txpwr(struct ieee80211_hw *hw,
+				struct ieee80211_vif *vif,
+				struct ieee80211_sta *sta)
+{
+	struct ath10k *ar = hw->priv;
+	struct ath10k_vif *arvif = ath10k_vif_to_arvif(vif);
+	int ret = 0;
+	u8 txpwr;
+
+	txpwr = sta->txpwr;
+	if (txpwr > ATH10K_TX_POWER_MAX_VAL || txpwr < ATH10K_TX_POWER_MIN_VAL)
+		return -EINVAL;
+
+	mutex_lock(&ar->conf_mutex);
+
+	ret = ath10k_wmi_peer_set_param(ar, arvif->vdev_id, sta->addr,
+					WMI_PEER_USE_FIXED_PWR, txpwr);
+	if (ret) {
+		ath10k_warn(ar, "failed to set tx power for station ret: %d\n",
+			    ret);
+		goto out;
+	}
+
+out:
+	mutex_unlock(&ar->conf_mutex);
+	return ret;
+}
+
 static int ath10k_sta_state(struct ieee80211_hw *hw,
 			    struct ieee80211_vif *vif,
 			    struct ieee80211_sta *sta,
@@ -7550,6 +7578,7 @@ static void ath10k_mac_op_sta_pre_rcu_remove(struct ieee80211_hw *hw,
 	.set_key			= ath10k_set_key,
 	.set_default_unicast_key        = ath10k_set_default_unicast_key,
 	.sta_state			= ath10k_sta_state,
+	.sta_set_txpwr			= ath10k_sta_set_txpwr,
 	.conf_tx			= ath10k_conf_tx,
 	.remain_on_channel		= ath10k_remain_on_channel,
 	.cancel_remain_on_channel	= ath10k_cancel_remain_on_channel,
@@ -8193,11 +8222,15 @@ int ath10k_mac_register(struct ath10k *ar)
 		ar->hw->wiphy->iface_combinations = ath10k_10x_if_comb;
 		ar->hw->wiphy->n_iface_combinations =
 			ARRAY_SIZE(ath10k_10x_if_comb);
+		wiphy_ext_feature_set(ar->hw->wiphy,
+				      NL80211_EXT_FEATURE_STA_TX_PWR);
 		break;
 	case ATH10K_FW_WMI_OP_VERSION_10_4:
 		ar->hw->wiphy->iface_combinations = ath10k_10_4_if_comb;
 		ar->hw->wiphy->n_iface_combinations =
 			ARRAY_SIZE(ath10k_10_4_if_comb);
+		wiphy_ext_feature_set(ar->hw->wiphy,
+				      NL80211_EXT_FEATURE_STA_TX_PWR);
 		break;
 	case ATH10K_FW_WMI_OP_VERSION_UNSET:
 	case ATH10K_FW_WMI_OP_VERSION_MAX:
diff --git a/drivers/net/wireless/ath/ath10k/wmi.h b/drivers/net/wireless/ath/ath10k/wmi.h
index 861c2d8..1ccb6bf 100644
--- a/drivers/net/wireless/ath/ath10k/wmi.h
+++ b/drivers/net/wireless/ath/ath10k/wmi.h
@@ -5811,6 +5811,7 @@ enum wmi_peer_param {
 	WMI_PEER_CHAN_WIDTH = 0x4,
 	WMI_PEER_NSS        = 0x5,
 	WMI_PEER_USE_4ADDR  = 0x6,
+	WMI_PEER_USE_FIXED_PWR = 0x8,
 	WMI_PEER_DUMMY_VAR  = 0xff, /* dummy parameter for STA PS workaround */
 };
 
-- 
1.9.1