HID: Introduce hidpp, a module to handle Logitech hid++ devices

Logitech devices use a vendor protocol to communicate various
information with the device. This protocol is called HID++,
and an exerpt can be found here:
https://drive.google.com/folderview?id=0BxbRzx7vEV7eWmgwazJ3NUFfQ28&usp=shar

The main difficulty which is related to this protocol is that
it is a synchronous protocol using the input reports.
So when we want to get some information from the device, we need
to wait for a matching input report.

This driver introduce this capabilities to be able to support
the multitouch mode of the Logitech Wireless Touchpad T651
(the bluetooth one). The multitouch data is available directly
from the mouse input reports, and we just need to query the device
on connect about its caracteristics.

HID++ and the touchpad features has a specific reporting mode
which uses pure HID++ reports, but Logitech told us not to use
it for this specific device. During QA, they detected that
some bluetooth input reports where lost, and so the only supported
mode is the pointer mode.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Andrew de los Reyes <adlr@chromium.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/Kconfig

@@ -378,6 +378,17 @@ config HID_LOGITECH_DJ
 	generic USB_HID driver and all incoming events will be multiplexed
 	into a single mouse and a single keyboard device.
 
+config HID_LOGITECH_HIDPP
+	tristate "Logitech HID++ devices support"
+	depends on HID_LOGITECH
+	---help---
+	Support for Logitech devices relyingon the HID++ Logitech specification
+
+	Say Y if you want support for Logitech devices relying on the HID++
+	specification. Such devices are the various Logitech Touchpads (T650,
+	T651, TK820), some mice (Zone Touch mouse), or even keyboards (Solar
+	Keayboard).
+
 config LOGITECH_FF
 	bool "Logitech force feedback support"
 	depends on HID_LOGITECH

drivers/hid/Makefile

@@ -63,6 +63,7 @@ obj-$(CONFIG_HID_LCPOWER)       += hid-lcpower.o
 obj-$(CONFIG_HID_LENOVO)	+= hid-lenovo.o
 obj-$(CONFIG_HID_LOGITECH)	+= hid-logitech.o
 obj-$(CONFIG_HID_LOGITECH_DJ)	+= hid-logitech-dj.o
+obj-$(CONFIG_HID_LOGITECH_HIDPP)	+= hid-logitech-hidpp.o
 obj-$(CONFIG_HID_MAGICMOUSE)    += hid-magicmouse.o
 obj-$(CONFIG_HID_MICROSOFT)	+= hid-microsoft.o
 obj-$(CONFIG_HID_MONTEREY)	+= hid-monterey.o

drivers/hid/hid-core.c

@@ -1818,6 +1818,7 @@ static const struct hid_device_id hid_have_special_driver[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_S510_RECEIVER_2) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_LOGITECH_RECEIVER) },
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_LOGITECH_HARMONY_PS3) },
+	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_LOGITECH_T651) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_DINOVO_DESKTOP) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_DINOVO_EDGE) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_DINOVO_MINI) },

drivers/hid/hid-ids.h

@@ -575,6 +575,7 @@
 
 #define USB_VENDOR_ID_LOGITECH		0x046d
 #define USB_DEVICE_ID_LOGITECH_AUDIOHUB 0x0a0e
+#define USB_DEVICE_ID_LOGITECH_T651	0xb00c
 #define USB_DEVICE_ID_LOGITECH_RECEIVER	0xc101
 #define USB_DEVICE_ID_LOGITECH_HARMONY_FIRST  0xc110
 #define USB_DEVICE_ID_LOGITECH_HARMONY_LAST 0xc14f