Bluetooth: Read adversiting channel TX power during init sequence

This patch adds the reading of the LE advertising channel TX power to
the HCI init sequence of LE-capable controllers. This data will be used
e.g. for inclusion in the advertising data packets when advertising is
enabled.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

include/net/bluetooth/hci.h

@@ -932,6 +932,12 @@ struct hci_rp_le_read_buffer_size {
 	__u8     le_max_pkt;
 } __packed;
 
+#define HCI_OP_LE_READ_ADV_TX_POWER	0x2007
+struct hci_rp_le_read_adv_tx_power {
+	__u8	status;
+	__s8	tx_power;
+} __packed;
+
 #define HCI_OP_LE_SET_SCAN_PARAM	0x200b
 struct hci_cp_le_set_scan_param {
 	__u8    type;

include/net/bluetooth/hci_core.h

@@ -278,6 +278,8 @@ struct hci_dev {
 	struct work_struct	le_scan;
 	struct le_scan_params	le_scan_params;
 
+	__s8			adv_tx_power;
+
 	int (*open)(struct hci_dev *hdev);
 	int (*close)(struct hci_dev *hdev);
 	int (*flush)(struct hci_dev *hdev);

net/bluetooth/hci_event.c

@@ -594,6 +594,9 @@ static void le_init(struct hci_dev *hdev)
 {
 	/* Read LE Buffer Size */
 	hci_send_cmd(hdev, HCI_OP_LE_READ_BUFFER_SIZE, 0, NULL);
+
+	/* Read LE Advertising Channel TX Power */
+	hci_send_cmd(hdev, HCI_OP_LE_READ_ADV_TX_POWER, 0, NULL);
 }
 
 static void hci_setup(struct hci_dev *hdev)
@@ -1073,6 +1076,19 @@ static void hci_cc_le_read_buffer_size(struct hci_dev *hdev,
 	hci_req_complete(hdev, HCI_OP_LE_READ_BUFFER_SIZE, rp->status);
 }
 
+static void hci_cc_le_read_adv_tx_power(struct hci_dev *hdev,
+					struct sk_buff *skb)
+{
+	struct hci_rp_le_read_adv_tx_power *rp = (void *) skb->data;
+
+	BT_DBG("%s status 0x%2.2x", hdev->name, rp->status);
+
+	if (!rp->status)
+		hdev->adv_tx_power = rp->tx_power;
+
+	hci_req_complete(hdev, HCI_OP_LE_READ_ADV_TX_POWER, rp->status);
+}
+
 static void hci_cc_le_set_event_mask(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	__u8 status = *((__u8 *) skb->data);
@@ -2505,6 +2521,10 @@ static void hci_cmd_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 		hci_cc_le_read_buffer_size(hdev, skb);
 		break;
 
+	case HCI_OP_LE_READ_ADV_TX_POWER:
+		hci_cc_le_read_adv_tx_power(hdev, skb);
+		break;
+
 	case HCI_OP_LE_SET_EVENT_MASK:
 		hci_cc_le_set_event_mask(hdev, skb);
 		break;