USB: qcserial: Add support for Qualcomm Gobi 2000 devices

Add ids for Qualcomm Gobi 2000 QDL and Modem modes. Gobi 2000 has a
single altsetting in QDL mode, so adapt code to handle that.

Firmware upload protocol is also slightly different, with an
additional firmware file. However, qcserial doesn't handle firmware
uploading.

Tested on Lenovo Thinkpad T510.
Signed-off-by: Anssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/qcserial.c

@@ -78,6 +78,8 @@ static const struct usb_device_id id_table[] = {
 	{USB_DEVICE(0x1199, 0x900a)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
 	{USB_DEVICE(0x16d8, 0x8001)},	/* CMDTech Gobi 2000 QDL device (VU922) */
 	{USB_DEVICE(0x16d8, 0x8002)},	/* CMDTech Gobi 2000 Modem device (VU922) */
+	{USB_DEVICE(0x05c6, 0x9204)},	/* Gobi 2000 QDL device */
+	{USB_DEVICE(0x05c6, 0x9205)},	/* Gobi 2000 Modem device */
 	{ }				/* Terminating entry */
 };
 MODULE_DEVICE_TABLE(usb, id_table);
@@ -95,6 +97,7 @@ static struct usb_driver qcdriver = {
 static int qcprobe(struct usb_serial *serial, const struct usb_device_id *id)
 {
 	struct usb_wwan_intf_private *data;
+	struct usb_host_interface *intf = serial->interface->cur_altsetting;
 	int retval = -ENODEV;
 	__u8 nintf;
 	__u8 ifnum;
@@ -103,7 +106,7 @@ static int qcprobe(struct usb_serial *serial, const struct usb_device_id *id)
 
 	nintf = serial->dev->actconfig->desc.bNumInterfaces;
 	dbg("Num Interfaces = %d", nintf);
-	ifnum = serial->interface->cur_altsetting->desc.bInterfaceNumber;
+	ifnum = intf->desc.bInterfaceNumber;
 	dbg("This Interface = %d", ifnum);
 
 	data = serial->private = kzalloc(sizeof(struct usb_wwan_intf_private),
@@ -116,14 +119,20 @@ static int qcprobe(struct usb_serial *serial, const struct usb_device_id *id)
 	switch (nintf) {
 	case 1:
 		/* QDL mode */
-		if (serial->interface->num_altsetting == 2) {
-			struct usb_host_interface *intf;
-
+		/* Gobi 2000 has a single altsetting, older ones have two */
+		if (serial->interface->num_altsetting == 2)
 			intf = &serial->interface->altsetting[1];
-			if (intf->desc.bNumEndpoints == 2) {
-				if (usb_endpoint_is_bulk_in(&intf->endpoint[0].desc) &&
+		else if (serial->interface->num_altsetting > 2)
+			break;
+
+		if (intf->desc.bNumEndpoints == 2 &&
+		    usb_endpoint_is_bulk_in(&intf->endpoint[0].desc) &&
 		    usb_endpoint_is_bulk_out(&intf->endpoint[1].desc)) {
 			dbg("QDL port found");
+
+			if (serial->interface->num_altsetting == 1)
+				return 0;
+
 			retval = usb_set_interface(serial->dev, ifnum, 1);
 			if (retval < 0) {
 				dev_err(&serial->dev->dev,
@@ -133,10 +142,9 @@ static int qcprobe(struct usb_serial *serial, const struct usb_device_id *id)
 			}
 			return retval;
 		}
-			}
-		}
 		break;
 
+	case 3:
 	case 4:
 		/* Composite mode */
 		if (ifnum == 2) {