usb: Add dial-up networking bridge host driver for PID:9001

This host driver will be used to connect directly to the modem
interface of Qualcomm devices. This will provide a bridge to
the gadget serial driver to enable dial-up networking. Though it
resembles the existing qcserial driver, this is intended only for
inter-driver usage and does not expose any interface to userland.

Change-Id: I8534a2eb0c6b747ff593f7e2efdb56da9ea6dddc
Signed-off-by: Jack Pham <jackp@codeaurora.org>
diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig
index 527dc85..1135806 100644
--- a/drivers/usb/misc/Kconfig
+++ b/drivers/usb/misc/Kconfig
@@ -280,3 +280,28 @@
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called qcaux.  If unsure, choose N.
+
+config USB_QCOM_DUN_BRIDGE
+	tristate "USB Qualcomm modem DUN bridge driver"
+	depends on USB && !USB_SERIAL_QUALCOMM
+	help
+	  Say Y here if you have a Qualcomm modem device connected via USB that
+	  will be bridged in kernel space. This driver will enable bridging
+	  with the gadget serial driver for use in dial-up networking. This is
+	  not the same as the qcserial driver that exposes a TTY interface to
+	  userspace.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called dun_bridge.
+
+config USB_QCOM_DUN_BRIDGE_TEST
+	tristate "USB Qualcomm modem DUN bridge driver test"
+	depends on USB && USB_QCOM_DUN_BRIDGE && !USB_SERIAL_QUALCOMM
+	help
+	  Say Y here if you want to enable the test hook for the
+	  Qualcomm modem bridge driver. When enabled, this will create
+	  a debugfs file entry named "dun_bridge_test" which can be used
+	  to read and write directly to the modem.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called dun_bridge_test.