[media] si470x: add check to test if this is really a si470x

[~andy/linux] / drivers / media / radio / si470x / radio-si470x-usb.c

diff --git a/drivers/media/radio/si470x/radio-si470x-usb.c b/drivers/media/radio/si470x/radio-si470x-usb.c
index cd74025517e5498f3fd8d8e0cac2e4b11a3a2c62..07ef40595efda9ccb9e50bda9646d1c6f66b3926 100644 (file)
--- a/drivers/media/radio/si470x/radio-si470x-usb.c
+++ b/drivers/media/radio/si470x/radio-si470x-usb.c
@@ -635,6 +635,30 @@ static int si470x_usb_driver_probe(struct usb_interface *intf,
        }
 
        radio->v4l2_dev.release = si470x_usb_release;
+
+       /*
+        * The si470x SiLabs reference design uses the same USB IDs as
+        * 'Thanko's Raremono' si4734 based receiver. So check here which we
+        * have: attempt to read the device ID from the si470x: the lower 12
+        * bits should be 0x0242 for the si470x.
+        *
+        * We use this check to determine which device we are dealing with.
+        */
+       if (id->idVendor == 0x10c4 && id->idProduct == 0x818a) {
+               retval = usb_control_msg(radio->usbdev,
+                               usb_rcvctrlpipe(radio->usbdev, 0),
+                               HID_REQ_GET_REPORT,
+                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
+                               1, 2,
+                               radio->usb_buf, 3, 500);
+               if (retval != 3 ||
+                   (get_unaligned_be16(&radio->usb_buf[1]) & 0xfff) != 0x0242) {
+                       dev_info(&intf->dev, "this is not a si470x device.\n");
+                       retval = -ENODEV;
+                       goto err_urb;
+               }
+       }
+
        retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
        if (retval < 0) {
                dev_err(&intf->dev, "couldn't register v4l2_device\n");