Input/Touchscreen Driver: add support AD7877 touchscreen driver (try #4)

From: Michael Hennerich <[email protected]>

[try #4] Changelog (based on LKML feedback by Dmitry Torokhov)
- Fix req use after free.
- Fix sysfs interaction (we migh re-eanble irgs upon a sysfs read).
- Fix DAC bogus data read case

[try #3] Changlog (Add feedback from Dmitry Torokhov):
- Change handling of spi_sync / spi_async return value handling
- Remove depreciated dev->power.power_state
- Fix error return path in ad7877_probe
- delete pending kernel timer
- Some minor cleanup (indention, use dev_err etc.)

[try #2] Changelog:
- move locking inside ad7877_enable and ad7877_disable
- use setup_timer
- use input_dev->dev.parent
- fix unregister device
- kill EV_KEY since it's not used
- fix indention style

Apply patch from Philip Douglass:
Make ad7877 ts driver not dependent on Blackfin specific cs_change_per_word_option

---
 drivers/input/touchscreen/Kconfig  |   13 +
 drivers/input/touchscreen/Makefile |    1 +
 drivers/input/touchscreen/ad7877.c |  902 ++++++++++++++++++++++++++++++++++++
 3 files changed, 916 insertions(+), 0 deletions(-)
 create mode 100644 drivers/input/touchscreen/ad7877.c

index 565ec71..4fdde92 100644
@@ -29,6 +29,19 @@ config TOUCHSCREEN_ADS7846
 	  To compile this driver as a module, choose M here: the
 	  module will be called ads7846.
 
+config TOUCHSCREEN_AD7877
+	tristate "AD7877 based touchscreens"
+	depends on SPI_MASTER
+	help
+	  Say Y here if you have a touchscreen interface using the
+	  AD7877 controller, and your board-specific initialization
+	  code includes that in its table of SPI devices.
+
+	  If unsure, say N (but it's safe to say "Y").
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad7877.
+
 config TOUCHSCREEN_BITSY
 	tristate "Compaq iPAQ H3600 (Bitsy) touchscreen"
 	depends on SA1100_BITSY

index 3c096d7..18b89c5 100644
@@ -6,6 +6,7 @@
 
 wm97xx-ts-y := wm97xx-core.o
 
+obj-$(CONFIG_TOUCHSCREEN_AD7877)	+= ad7877.o
 obj-$(CONFIG_TOUCHSCREEN_ADS7846)	+= ads7846.o
 obj-$(CONFIG_TOUCHSCREEN_BITSY)		+= h3600_ts_input.o
 obj-$(CONFIG_TOUCHSCREEN_CORGI)		+= corgi_ts.o

1.5.5