USB: usbtmc: Set rigol_quirk if device is listed

These patches implement a modification of the USBTMC
protocol to allow operation with Rigol equipment. It an idVendor and
idProduct is found on the usbtmc_id_quirk array, the rigol_quirk is set for
this device.

Signed-off-by: Alexandre Peixoto Ferreira <alexandref75@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 9c37042..fd2f90d 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -1040,6 +1040,20 @@
 	mutex_init(&data->io_mutex);
 	data->zombie = 0;
 
+	/* Determine if it is a Rigol or not */
+	data->rigol_quirk = 0;
+	dev_dbg(&intf->dev, "Trying to find if device Vendor 0x%04X Product 0x%04X has the RIGOL quirk\n",
+		data->usb_dev->descriptor.idVendor,
+		data->usb_dev->descriptor.idProduct);
+	for(n = 0; usbtmc_id_quirk[n].idVendor > 0; n++) {
+		if ((usbtmc_id_quirk[n].idVendor == data->usb_dev->descriptor.idVendor) &&
+		    (usbtmc_id_quirk[n].idProduct == data->usb_dev->descriptor.idProduct)) {
+			dev_dbg(&intf->dev, "Setting this device as having the RIGOL quirk\n");
+			data->rigol_quirk = 1;
+			break;
+		}
+	}
+
 	/* Initialize USBTMC bTag and other fields */
 	data->bTag	= 1;
 	data->TermCharEnabled = 0;