USB: serial: add Google simple serial SubClass support

commit 679315e5 upstream.

Add support for Google devices that export simple serial
interfaces using the vendor specific SubClass/Protocol pair
0x50/0x01.
Signed-off-by: Anton Staaf <robotboy@chromium.org>
Reviewed-by: Benson Leung <bleung@chromium.org>
[johan: move id entries and update Kconfig]
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/usb/serial/Kconfig

@@ -59,6 +59,7 @@ config USB_SERIAL_SIMPLE
 	  driver.  Specifically, it supports:
 		- Suunto ANT+ USB device.
 		- Fundamental Software dongle.
+		- Google USB serial devices
 		- HP4x calculators
 		- a number of Motorola phones
 		- Siemens USB/MPI adapter.

drivers/usb/serial/usb-serial-simple.c

@@ -50,6 +50,14 @@ DEVICE(funsoft, FUNSOFT_IDS);
 	{ USB_DEVICE(0x8087, 0x0716) }
 DEVICE(flashloader, FLASHLOADER_IDS);
 
+/* Google Serial USB SubClass */
+#define GOOGLE_IDS()						\
+	{ USB_VENDOR_AND_INTERFACE_INFO(0x18d1,			\
+					USB_CLASS_VENDOR_SPEC,	\
+					0x50,			\
+					0x01) }
+DEVICE(google, GOOGLE_IDS);
+
 /* ViVOpay USB Serial Driver */
 #define VIVOPAY_IDS()			\
 	{ USB_DEVICE(0x1d5f, 0x1004) }	/* ViVOpay 8800 */
@@ -85,6 +93,7 @@ static struct usb_serial_driver * const serial_drivers[] = {
 	&zio_device,
 	&funsoft_device,
 	&flashloader_device,
+	&google_device,
 	&vivopay_device,
 	&moto_modem_device,
 	&hp4x_device,
@@ -97,6 +106,7 @@ static const struct usb_device_id id_table[] = {
 	ZIO_IDS(),
 	FUNSOFT_IDS(),
 	FLASHLOADER_IDS(),
+	GOOGLE_IDS(),
 	VIVOPAY_IDS(),
 	MOTO_IDS(),
 	HP4X_IDS(),