Input: add AD7879 Touchscreen driver

[randy.dunlap@oracle.com: don't use bus_id]
[dtor@mail.ru: locking and other fixups]
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/touchscreen/Kconfig

@@ -42,6 +42,38 @@ config TOUCHSCREEN_AD7877
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad7877.
 
+config TOUCHSCREEN_AD7879_I2C
+	tristate "AD7879 based touchscreens: AD7879-1 I2C Interface"
+	depends on I2C
+	select TOUCHSCREEN_AD7879
+	help
+	  Say Y here if you have a touchscreen interface using the
+	  AD7879-1 controller, and your board-specific initialization
+	  code includes that in its table of I2C 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 ad7879.
+
+config TOUCHSCREEN_AD7879_SPI
+	tristate "AD7879 based touchscreens: AD7879 SPI Interface"
+	depends on SPI_MASTER && TOUCHSCREEN_AD7879_I2C = n
+	select TOUCHSCREEN_AD7879
+	help
+	  Say Y here if you have a touchscreen interface using the
+	  AD7879 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 ad7879.
+
+config TOUCHSCREEN_AD7879
+	tristate
+	default n
+
 config TOUCHSCREEN_BITSY
 	tristate "Compaq iPAQ H3600 (Bitsy) touchscreen"
 	depends on SA1100_BITSY

drivers/input/touchscreen/Makefile

@@ -7,6 +7,7 @@
 wm97xx-ts-y := wm97xx-core.o
 
 obj-$(CONFIG_TOUCHSCREEN_AD7877)	+= ad7877.o
+obj-$(CONFIG_TOUCHSCREEN_AD7879)	+= ad7879.o
 obj-$(CONFIG_TOUCHSCREEN_ADS7846)	+= ads7846.o
 obj-$(CONFIG_TOUCHSCREEN_ATMEL_TSADCC)	+= atmel_tsadcc.o
 obj-$(CONFIG_TOUCHSCREEN_BITSY)		+= h3600_ts_input.o

include/linux/spi/ad7879.h

+/* linux/spi/ad7879.h */
+
+/* Touchscreen characteristics vary between boards and models.  The
+ * platform_data for the device's "struct device" holds this information.
+ *
+ * It's OK if the min/max values are zero.
+ */
+struct ad7879_platform_data {
+	u16	model;			/* 7879 */
+	u16	x_plate_ohms;
+	u16	x_min, x_max;
+	u16	y_min, y_max;
+	u16	pressure_min, pressure_max;
+
+	/* [0..255] 0=OFF Starts at 1=550us and goes
+	 * all the way to 9.440ms in steps of 35us.
+	 */
+	u8	pen_down_acc_interval;
+	/* [0..15] Starts at 0=128us and goes all the
+	 * way to 4.096ms in steps of 128us.
+	 */
+	u8	first_conversion_delay;
+	/* [0..3] 0 = 2us, 1 = 4us, 2 = 8us, 3 = 16us */
+	u8	acquisition_time;
+	/* [0..3] Average X middle samples 0 = 2, 1 = 4, 2 = 8, 3 = 16 */
+	u8	averaging;
+	/* [0..3] Perform X measurements 0 = OFF,
+	 * 1 = 4, 2 = 8, 3 = 16 (median > averaging)
+	 */
+	u8	median;
+	/* 1 = AUX/VBAT/GPIO set to GPIO Output */
+	u8	gpio_output;
+	/* Initial GPIO pin state (valid if gpio_output = 1) */
+	u8	gpio_default;
+};