Input: Add support for ILITEK Lego Series

Add support for ILITEK Lego series of touch devices.
Lego series includes ILITEK 213X/23XX/25XX.

Tested/passed with evaluation board with ILI2520/2322 IC.
Signed-off-by: Joe Hung <joe_hung@ilitek.com>
Link: https://lore.kernel.org/r/20210324122601.125873-2-joe_hung@ilitek.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/Kconfig

@@ -426,6 +426,18 @@ config TOUCHSCREEN_ILI210X
 	  To compile this driver as a module, choose M here: the
 	  module will be called ili210x.
 
+config TOUCHSCREEN_ILITEK
+	tristate "Ilitek I2C 213X/23XX/25XX/Lego Series Touch ICs"
+	depends on I2C
+	help
+	  Say Y here if you have touchscreen with ILITEK touch IC,
+	  it supports 213X/23XX/25XX and other Lego series.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ilitek_ts_i2c.
+
 config TOUCHSCREEN_IPROC
 	tristate "IPROC touch panel driver support"
 	depends on ARCH_BCM_IPROC || COMPILE_TEST

drivers/input/touchscreen/Makefile

@@ -46,6 +46,7 @@ obj-$(CONFIG_TOUCHSCREEN_FUJITSU)	+= fujitsu_ts.o
 obj-$(CONFIG_TOUCHSCREEN_GOODIX)	+= goodix.o
 obj-$(CONFIG_TOUCHSCREEN_HIDEEP)	+= hideep.o
 obj-$(CONFIG_TOUCHSCREEN_ILI210X)	+= ili210x.o
+obj-$(CONFIG_TOUCHSCREEN_ILITEK)	+= ilitek_ts_i2c.o
 obj-$(CONFIG_TOUCHSCREEN_IMX6UL_TSC)	+= imx6ul_tsc.o
 obj-$(CONFIG_TOUCHSCREEN_INEXIO)	+= inexio.o
 obj-$(CONFIG_TOUCHSCREEN_IPROC)		+= bcm_iproc_tsc.o