Bluetooth: Expose debugfs settings for LE connection interval

For testing purposes expose the default LE connection interval values
via debugfs.

Signed-off-by: Marcel Holtmann <[e-mail]>
Signed-off-by: Johan Hedberg <[e-mail]>

include/net/bluetooth/hci_core.h

···
 	__u8		page_scan_type;
 	__u16		le_scan_interval;
 	__u16		le_scan_window;
+	__u16		le_conn_min_interval;
+	__u16		le_conn_max_interval;
 	__u8		ssp_debug_mode;
 
 	__u16		devid_source;

net/bluetooth/hci_conn.c

···
 	bacpy(&cp.peer_addr, &conn->dst);
 	cp.peer_addr_type = conn->dst_type;
 	cp.own_address_type = conn->src_type;
-	cp.conn_interval_min = __constant_cpu_to_le16(0x0028);
-	cp.conn_interval_max = __constant_cpu_to_le16(0x0038);
+	cp.conn_interval_min = cpu_to_le16(hdev->le_conn_min_interval);
+	cp.conn_interval_max = cpu_to_le16(hdev->le_conn_max_interval);
 	cp.supervision_timeout = __constant_cpu_to_le16(0x002a);
 	cp.min_ce_len = __constant_cpu_to_le16(0x0000);
 	cp.max_ce_len = __constant_cpu_to_le16(0x0000);
+
 	hci_req_add(&req, HCI_OP_LE_CREATE_CONN, sizeof(cp), &cp);
 
 	err = hci_req_run(&req, create_le_conn_complete);

net/bluetooth/hci_core.c

···
 	.release	= single_release,
 };
 
+static int conn_min_interval_set(void *data, u64 val)
+{
+	struct hci_dev *hdev = data;
+
+	if (val < 0x0006 || val > 0x0c80 || val > hdev->le_conn_max_interval)
+		return -EINVAL;
+
+	hci_dev_lock(hdev);
+	hdev->le_conn_min_interval= val;
+	hci_dev_unlock(hdev);
+
+	return 0;
+}
+
+static int conn_min_interval_get(void *data, u64 *val)
+{
+	struct hci_dev *hdev = data;
+
+	hci_dev_lock(hdev);
+	*val = hdev->le_conn_min_interval;
+	hci_dev_unlock(hdev);
+
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(conn_min_interval_fops, conn_min_interval_get,
+			conn_min_interval_set, "%llu\n");
+
+static int conn_max_interval_set(void *data, u64 val)
+{
+	struct hci_dev *hdev = data;
+
+	if (val < 0x0006 || val > 0x0c80 || val < hdev->le_conn_min_interval)
+		return -EINVAL;
+
+	hci_dev_lock(hdev);
+	hdev->le_conn_max_interval= val;
+	hci_dev_unlock(hdev);
+
+	return 0;
+}
+
+static int conn_max_interval_get(void *data, u64 *val)
+{
+	struct hci_dev *hdev = data;
+
+	hci_dev_lock(hdev);
+	*val = hdev->le_conn_max_interval;
+	hci_dev_unlock(hdev);
+
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(conn_max_interval_fops, conn_max_interval_get,
+			conn_max_interval_set, "%llu\n");
+
 /* ---- HCI requests ---- */
 
 static void hci_req_sync_complete(struct hci_dev *hdev, u8 result)
···
 				    hdev, &own_address_type_fops);
 		debugfs_create_file("long_term_keys", 0400, hdev->debugfs,
 				    hdev, &long_term_keys_fops);
+		debugfs_create_file("conn_min_interval", 0644, hdev->debugfs,
+				    hdev, &conn_min_interval_fops);
+		debugfs_create_file("conn_max_interval", 0644, hdev->debugfs,
+				    hdev, &conn_max_interval_fops);
 	}
 
 	return 0;
···
 
 	hdev->le_scan_interval = 0x0060;
 	hdev->le_scan_window = 0x0030;
+	hdev->le_conn_min_interval = 0x0028;
+	hdev->le_conn_max_interval = 0x0038;
 
 	mutex_init(&hdev->lock);
 	mutex_init(&hdev->req_lock);