Input: add driver for the Goodix touchpanel

Add a driver for the Goodix touchscreen panel found in Onda v975w tablets.
The driver is based off the Android driver gt9xx.c found in some Android
code dumps, but now bears no resemblance to the original driver.

The driver was tested on the aforementioned tablet.

Signed-off-by: Bastien Nocera <hadess@hadess.net>
Tested-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

MAINTAINERS

@@ -4062,6 +4062,12 @@ L:	linux-media@vger.kernel.org
 S:	Maintained
 F:	drivers/media/usb/go7007/
 
+GOODIX TOUCHSCREEN
+M:	Bastien Nocera <hadess@hadess.net>
+L:	linux-input@vger.kernel.org
+S:	Maintained
+F:	drivers/input/touchscreen/goodix.c
+
 GPIO SUBSYSTEM
 M:	Linus Walleij <linus.walleij@linaro.org>
 M:	Alexandre Courbot <gnurou@gmail.com>

drivers/input/touchscreen/Kconfig

@@ -295,6 +295,19 @@ config TOUCHSCREEN_FUJITSU
 	  To compile this driver as a module, choose M here: the
 	  module will be called fujitsu-ts.
 
+config TOUCHSCREEN_GOODIX
+	tristate "Goodix I2C touchscreen"
+	depends on I2C && ACPI
+	help
+	  Say Y here if you have the Goodix touchscreen (such as one
+	  installed in Onda v975w tablets) connected to your
+	  system.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called goodix.
+
 config TOUCHSCREEN_ILI210X
 	tristate "Ilitek ILI210X based touchscreen"
 	depends on I2C

drivers/input/touchscreen/Makefile

@@ -34,6 +34,7 @@ obj-$(CONFIG_TOUCHSCREEN_EETI)		+= eeti_ts.o
 obj-$(CONFIG_TOUCHSCREEN_ELO)		+= elo.o
 obj-$(CONFIG_TOUCHSCREEN_EGALAX)	+= egalax_ts.o
 obj-$(CONFIG_TOUCHSCREEN_FUJITSU)	+= fujitsu_ts.o
+obj-$(CONFIG_TOUCHSCREEN_GOODIX)	+= goodix.o
 obj-$(CONFIG_TOUCHSCREEN_ILI210X)	+= ili210x.o
 obj-$(CONFIG_TOUCHSCREEN_INEXIO)	+= inexio.o
 obj-$(CONFIG_TOUCHSCREEN_INTEL_MID)	+= intel-mid-touch.o