Input: add wm97xx accelerated driver for Atmel microprocessors

This patch adds an accelerated driver for Atmel AVR32 AT32AP700X
microprocessors. It uses interrupts on the channel B in the AC97
controller. Thus, offloading the work queue in the wm97xx-ts driver.

The driver has been tested with Atmel AVR32 AT32AP7000 and Wolfson
WM9712 codec.

The driver can also be easily modified to support Atmel AT91 devices, as
AT91 and AVR32 share the same AC97C module.

[Fixed leak of atmel_wm97xx when probe fails. -- broonie]
[dtor@mail.ru: do not report ABS_PRESSURE events when not measuring pressure]
Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/touchscreen/Kconfig

@@ -341,6 +341,21 @@ config TOUCHSCREEN_WM9713
 	  Say Y here to enable support for the Wolfson Microelectronics
 	  WM9713 touchscreen controller.
 
+config TOUCHSCREEN_WM97XX_ATMEL
+	tristate "WM97xx Atmel accelerated touch"
+	depends on TOUCHSCREEN_WM97XX && (AVR32 || ARCH_AT91)
+	help
+	  Say Y here for support for streaming mode with WM97xx touchscreens
+	  on Atmel AT91 or AVR32 systems with an AC97C module.
+
+	  Be aware that this will use channel B in the controller for
+	  streaming data, this must not conflict with other AC97C drivers.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called atmel-wm97xx.
+
 config TOUCHSCREEN_WM97XX_MAINSTONE
 	tristate "WM97xx Mainstone accelerated touch"
 	depends on TOUCHSCREEN_WM97XX && ARCH_PXA

drivers/input/touchscreen/Makefile

@@ -35,5 +35,6 @@ obj-$(CONFIG_TOUCHSCREEN_DA9034)	+= da9034-ts.o
 wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9705)	+= wm9705.o
 wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9712)	+= wm9712.o
 wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9713)	+= wm9713.o
+obj-$(CONFIG_TOUCHSCREEN_WM97XX_ATMEL)	+= atmel-wm97xx.o
 obj-$(CONFIG_TOUCHSCREEN_WM97XX_MAINSTONE)	+= mainstone-wm97xx.o
 obj-$(CONFIG_TOUCHSCREEN_WM97XX_ZYLONITE)	+= zylonite-wm97xx.o