net: qmi_wwan: use a single bind function for all device types

Refactoring the bind code lets us use a common driver_info struct
for all supported devices, simplifying the code a bit.  The
real advantage is that devices using the CDC ECM interface
layout now also can be added dynamically using the new_id sysfs
interface.  This simplifies testing of new devices.

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/qmi_wwan.c

@@ -139,10 +139,18 @@ static int qmi_wwan_bind(struct usbnet *dev, struct usb_interface *intf)
 
 	BUILD_BUG_ON((sizeof(((struct usbnet *)0)->data) < sizeof(struct qmi_wwan_state)));
 
-	/* require a single interrupt status endpoint for subdriver */
+	/* control and data is shared? */
+	if (intf->cur_altsetting->desc.bNumEndpoints == 3) {
+		info->control = intf;
+		info->data = intf;
+		goto shared;
+	}
+
+	/* else require a single interrupt status endpoint on control intf */
 	if (intf->cur_altsetting->desc.bNumEndpoints != 1)
 		goto err;
 
+	/* and a number of CDC descriptors */
 	while (len > 3) {
 		struct usb_descriptor_header *h = (void *)buf;
 
@@ -231,8 +239,9 @@ next_desc:
 	if (status < 0)
 		goto err;
 
+shared:
 	status = qmi_wwan_register_subdriver(dev);
-	if (status < 0) {
+	if (status < 0 && info->control != info->data) {
 		usb_set_intfdata(info->data, NULL);
 		usb_driver_release_interface(driver, info->data);
 	}
@@ -241,20 +250,6 @@ err:
 	return status;
 }
 
-/* Some devices combine the "control" and "data" functions into a
- * single interface with all three endpoints: interrupt + bulk in and
- * out
- */
-static int qmi_wwan_bind_shared(struct usbnet *dev, struct usb_interface *intf)
-{
-	struct qmi_wwan_state *info = (void *)&dev->data;
-
-	/*  control and data is shared */
-	info->control = intf;
-	info->data = intf;
-	return qmi_wwan_register_subdriver(dev);
-}
-
 static void qmi_wwan_unbind(struct usbnet *dev, struct usb_interface *intf)
 {
 	struct qmi_wwan_state *info = (void *)&dev->data;
@@ -330,20 +325,12 @@ static const struct driver_info	qmi_wwan_info = {
 	.manage_power	= qmi_wwan_manage_power,
 };
 
-static const struct driver_info	qmi_wwan_shared = {
-	.description	= "WWAN/QMI device",
-	.flags		= FLAG_WWAN,
-	.bind		= qmi_wwan_bind_shared,
-	.unbind		= qmi_wwan_unbind,
-	.manage_power	= qmi_wwan_manage_power,
-};
-
 #define HUAWEI_VENDOR_ID	0x12D1
 
 /* map QMI/wwan function by a fixed interface number */
 #define QMI_FIXED_INTF(vend, prod, num) \
 	USB_DEVICE_INTERFACE_NUMBER(vend, prod, num), \
-	.driver_info = (unsigned long)&qmi_wwan_shared
+	.driver_info = (unsigned long)&qmi_wwan_info
 
 /* Gobi 1000 QMI/wwan interface number is 3 according to qcserial */
 #define QMI_GOBI1K_DEVICE(vend, prod) \
@@ -367,15 +354,15 @@ static const struct usb_device_id products[] = {
 	/* 2. Combined interface devices matching on class+protocol */
 	{	/* Huawei E392, E398 and possibly others in "Windows mode" */
 		USB_VENDOR_AND_INTERFACE_INFO(HUAWEI_VENDOR_ID, USB_CLASS_VENDOR_SPEC, 1, 17),
-		.driver_info        = (unsigned long)&qmi_wwan_shared,
+		.driver_info        = (unsigned long)&qmi_wwan_info,
 	},
 	{	/* Pantech UML290 */
 		USB_DEVICE_AND_INTERFACE_INFO(0x106c, 0x3718, USB_CLASS_VENDOR_SPEC, 0xf0, 0xff),
-		.driver_info        = (unsigned long)&qmi_wwan_shared,
+		.driver_info        = (unsigned long)&qmi_wwan_info,
 	},
 	{	/* Pantech UML290 - newer firmware */
 		USB_DEVICE_AND_INTERFACE_INFO(0x106c, 0x3718, USB_CLASS_VENDOR_SPEC, 0xf1, 0xff),
-		.driver_info        = (unsigned long)&qmi_wwan_shared,
+		.driver_info        = (unsigned long)&qmi_wwan_info,
 	},
 
 	/* 3. Combined interface devices matching on interface number */
@@ -457,7 +444,7 @@ static int qmi_wwan_probe(struct usb_interface *intf, const struct usb_device_id
 	 */
 	if (!id->driver_info) {
 		dev_dbg(&intf->dev, "setting defaults for dynamic device id\n");
-		id->driver_info = (unsigned long)&qmi_wwan_shared;
+		id->driver_info = (unsigned long)&qmi_wwan_info;
 	}
 
 	return usbnet_probe(intf, id);