[Bluetooth] Integrate low-level connections into the driver model

This patch integrates the low-level connections (ACL and SCO) into the
driver model. Every connection is presented as device with the parent
set to its host controller device.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/hci_core.h

@@ -165,6 +165,10 @@ struct hci_conn {
 	struct timer_list disc_timer;
 	struct timer_list idle_timer;
 
+	struct work_struct work;
+
+	struct device	dev;
+
 	struct hci_dev	*hdev;
 	void		*l2cap_data;
 	void		*sco_data;
@@ -412,6 +416,8 @@ static inline int hci_recv_frame(struct sk_buff *skb)
 
 int hci_register_sysfs(struct hci_dev *hdev);
 void hci_unregister_sysfs(struct hci_dev *hdev);
+void hci_conn_add_sysfs(struct hci_conn *conn);
+void hci_conn_del_sysfs(struct hci_conn *conn);
 
 #define SET_HCIDEV_DEV(hdev, pdev) ((hdev)->parent = (pdev))
 

net/bluetooth/hci_conn.c

@@ -179,6 +179,8 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst)
 	if (hdev->notify)
 		hdev->notify(hdev, HCI_NOTIFY_CONN_ADD);
 
+	hci_conn_add_sysfs(conn);
+
 	tasklet_enable(&hdev->tx_task);
 
 	return conn;
@@ -211,6 +213,8 @@ int hci_conn_del(struct hci_conn *conn)
 
 	tasklet_disable(&hdev->tx_task);
 
+	hci_conn_del_sysfs(conn);
+
 	hci_conn_hash_del(hdev, conn);
 	if (hdev->notify)
 		hdev->notify(hdev, HCI_NOTIFY_CONN_DEL);
@@ -221,7 +225,9 @@ int hci_conn_del(struct hci_conn *conn)
 
 	hci_dev_put(hdev);
 
-	kfree(conn);
+	/* will free via device release */
+	put_device(&conn->dev);
+
 	return 0;
 }
 

net/bluetooth/hci_sysfs.c

@@ -170,6 +170,32 @@ static struct device_attribute *bt_attrs[] = {
 	NULL
 };
 
+static ssize_t show_conn_type(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct hci_conn *conn = dev_get_drvdata(dev);
+	return sprintf(buf, "%s\n", conn->type == ACL_LINK ? "ACL" : "SCO");
+}
+
+static ssize_t show_conn_address(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct hci_conn *conn = dev_get_drvdata(dev);
+	bdaddr_t bdaddr;
+	baswap(&bdaddr, &conn->dst);
+	return sprintf(buf, "%s\n", batostr(&bdaddr));
+}
+
+#define CONN_ATTR(_name,_mode,_show,_store) \
+struct device_attribute conn_attr_##_name = __ATTR(_name,_mode,_show,_store)
+
+static CONN_ATTR(type, S_IRUGO, show_conn_type, NULL);
+static CONN_ATTR(address, S_IRUGO, show_conn_address, NULL);
+
+static struct device_attribute *conn_attrs[] = {
+	&conn_attr_type,
+	&conn_attr_address,
+	NULL
+};
+
 struct class *bt_class = NULL;
 EXPORT_SYMBOL_GPL(bt_class);
 
@@ -181,8 +207,57 @@ static struct platform_device *bt_platform;
 
 static void bt_release(struct device *dev)
 {
-	struct hci_dev *hdev = dev_get_drvdata(dev);
-	kfree(hdev);
+	void *data = dev_get_drvdata(dev);
+	kfree(data);
+}
+
+static void add_conn(void *data)
+{
+	struct hci_conn *conn = data;
+	int i;
+
+	device_register(&conn->dev);
+
+	for (i = 0; conn_attrs[i]; i++)
+		device_create_file(&conn->dev, conn_attrs[i]);
+}
+
+void hci_conn_add_sysfs(struct hci_conn *conn)
+{
+	struct hci_dev *hdev = conn->hdev;
+	bdaddr_t *ba = &conn->dst;
+
+	BT_DBG("conn %p", conn);
+
+	conn->dev.parent  = &hdev->dev;
+	conn->dev.release = bt_release;
+
+	snprintf(conn->dev.bus_id, BUS_ID_SIZE,
+			"%s%2.2X%2.2X%2.2X%2.2X%2.2X%2.2X",
+			conn->type == ACL_LINK ? "acl" : "sco",
+			ba->b[5], ba->b[4], ba->b[3],
+			ba->b[2], ba->b[1], ba->b[0]);
+
+	dev_set_drvdata(&conn->dev, conn);
+
+	INIT_WORK(&conn->work, add_conn, (void *) conn);
+
+	schedule_work(&conn->work);
+}
+
+static void del_conn(void *data)
+{
+	struct hci_conn *conn = data;
+	device_del(&conn->dev);
+}
+
+void hci_conn_del_sysfs(struct hci_conn *conn)
+{
+	BT_DBG("conn %p", conn);
+
+	INIT_WORK(&conn->work, del_conn, (void *) conn);
+
+	schedule_work(&conn->work);
 }
 
 int hci_register_sysfs(struct hci_dev *hdev)