net: cdc_ncm: add Huawei devices

A number of Huawei 3G and LTE modems implement a CDC NCM function,
including the necessary functional descriptors, but using a non
standard interface layout and class/subclass/protocol codes.

These devices can be handled by this driver with only a minor
change to the probing logic, allowing a single combined control
and data interface.  This works because the devices
- include a CDC Union descriptor labelling the combined
  interface as both master and slave, and
- have an alternate setting #1 for the bulk endpoints on the
  combined interface.

The 3G/LTE network connection is managed by vendor specific AT
commands on a serial function in the same composite device.
Handling the managment function is out of the scope of this
driver.  It will be handled by an appropriate USB serial
driver.

Reported-and-Tested-by: Olof Ermis <olof.ermis@gmail.com>
Reported-and-Tested-by: Tommy Cheng <tommy7765@yahoo.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 18 insertions, 4 deletions

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 4cd582a4f625..74fab1a40156 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -540,10 +540,12 @@ advance:
             (ctx->ether_desc == NULL) || (ctx->control != intf))
                 goto error;
 
-        /* claim interfaces, if any */
-        temp = usb_driver_claim_interface(driver, ctx->data, dev);
-        if (temp)
-                goto error;
+        /* claim data interface, if different from control */
+        if (ctx->data != ctx->control) {
+                temp = usb_driver_claim_interface(driver, ctx->data, dev);
+                if (temp)
+                        goto error;
+        }
 
         iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
 
@@ -623,6 +625,10 @@ static void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
 
         tasklet_kill(&ctx->bh);
 
+        /* handle devices with combined control and data interface */
+        if (ctx->control == ctx->data)
+                ctx->data = NULL;
+
         /* disconnect master --> disconnect slave */
         if (intf == ctx->control && ctx->data) {
                 usb_set_intfdata(ctx->data, NULL);
@@ -1245,6 +1251,14 @@ static const struct usb_device_id cdc_devs[] = {
           .driver_info = (unsigned long) &wwan_info,
         },
 
+        /* Huawei NCM devices disguised as vendor specific */
+        { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x16),
+          .driver_info = (unsigned long)&wwan_info,
+        },
+        { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x46),
+          .driver_info = (unsigned long)&wwan_info,
+        },
+
         /* Generic CDC-NCM devices */
         { USB_INTERFACE_INFO(USB_CLASS_COMM,
                 USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),