Bluetooth: Store TX power level for connection

This patch adds support to store local TX power level for connection
when reply for HCI_Read_Transmit_Power_Level is received.
Signed-off-by: Andrzej Kaczmarek <andrzej.kaczmarek@tieto.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/hci.h

@@ -1054,6 +1054,17 @@ struct hci_cp_write_page_scan_activity {
 	__le16   window;
 } __packed;
 
+#define HCI_OP_READ_TX_POWER		0x0c2d
+struct hci_cp_read_tx_power {
+	__le16   handle;
+	__u8     type;
+} __packed;
+struct hci_rp_read_tx_power {
+	__u8     status;
+	__le16   handle;
+	__s8     tx_power;
+} __packed;
+
 #define HCI_OP_READ_PAGE_SCAN_TYPE	0x0c46
 struct hci_rp_read_page_scan_type {
 	__u8     status;

include/net/bluetooth/hci_core.h

@@ -375,6 +375,7 @@ struct hci_conn {
 	__u16		le_conn_min_interval;
 	__u16		le_conn_max_interval;
 	__s8		rssi;
+	__s8		tx_power;
 	unsigned long	flags;
 
 	__u8		remote_cap;

net/bluetooth/hci_conn.c

@@ -407,6 +407,7 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst)
 	conn->io_capability = hdev->io_capability;
 	conn->remote_auth = 0xff;
 	conn->key_type = 0xff;
+	conn->tx_power = HCI_TX_POWER_INVALID;
 
 	set_bit(HCI_CONN_POWER_SAVE, &conn->flags);
 	conn->disc_timeout = HCI_DISCONN_TIMEOUT;

net/bluetooth/hci_event.c

@@ -1264,6 +1264,30 @@ static void hci_cc_read_rssi(struct hci_dev *hdev, struct sk_buff *skb)
 	hci_dev_unlock(hdev);
 }
 
+static void hci_cc_read_tx_power(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct hci_cp_read_tx_power *sent;
+	struct hci_rp_read_tx_power *rp = (void *) skb->data;
+	struct hci_conn *conn;
+
+	BT_DBG("%s status 0x%2.2x", hdev->name, rp->status);
+
+	if (rp->status)
+		return;
+
+	sent = hci_sent_cmd_data(hdev, HCI_OP_READ_TX_POWER);
+	if (!sent)
+		return;
+
+	hci_dev_lock(hdev);
+
+	conn = hci_conn_hash_lookup_handle(hdev, __le16_to_cpu(rp->handle));
+	if (conn && sent->type == 0x00)
+		conn->tx_power = rp->tx_power;
+
+	hci_dev_unlock(hdev);
+}
+
 static void hci_cs_inquiry(struct hci_dev *hdev, __u8 status)
 {
 	BT_DBG("%s status 0x%2.2x", hdev->name, status);
@@ -2660,6 +2684,10 @@ static void hci_cmd_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 		hci_cc_read_rssi(hdev, skb);
 		break;
 
+	case HCI_OP_READ_TX_POWER:
+		hci_cc_read_tx_power(hdev, skb);
+		break;
+
 	default:
 		BT_DBG("%s opcode 0x%4.4x", hdev->name, opcode);
 		break;