Input: touchscreen: Add imx25 TCQ driver

This is a driver for the imx25 ADC/TSC module. It controls the
touchscreen conversion queue and creates a touchscreen input device.
The driver currently only supports 4 wire touchscreens. The driver uses
a simple conversion queue of precharge, touch detection, X measurement,
Y measurement, precharge and another touch detection.

This driver uses the regmap from the parent to setup some touch specific
settings in the core driver and setup a idle configuration with touch
detection.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Denis Carikli <denis@eukrea.com>
[fix clock's period calculation]
[fix calculation of the 'settling' value]
Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/input/touchscreen/Kconfig

@@ -822,6 +822,15 @@ config TOUCHSCREEN_USB_COMPOSITE
 	  To compile this driver as a module, choose M here: the
 	  module will be called usbtouchscreen.
 
+config TOUCHSCREEN_MX25
+	tristate "Freescale i.MX25 touchscreen input driver"
+	depends on MFD_MX25_TSADC
+	help
+	  Enable support for touchscreen connected to your i.MX25.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called fsl-imx25-tcq.
+
 config TOUCHSCREEN_MC13783
 	tristate "Freescale MC13783 touchscreen input driver"
 	depends on MFD_MC13XXX

drivers/input/touchscreen/Makefile

@@ -46,6 +46,7 @@ obj-$(CONFIG_TOUCHSCREEN_INTEL_MID)	+= intel-mid-touch.o
 obj-$(CONFIG_TOUCHSCREEN_IPROC)		+= bcm_iproc_tsc.o
 obj-$(CONFIG_TOUCHSCREEN_LPC32XX)	+= lpc32xx_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MAX11801)	+= max11801_ts.o
+obj-$(CONFIG_TOUCHSCREEN_MX25)		+= fsl-imx25-tcq.o
 obj-$(CONFIG_TOUCHSCREEN_MC13783)	+= mc13783_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MCS5000)	+= mcs5000_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MIGOR)		+= migor_ts.o