Input: add Analog Devices AD714x captouch input driver

AD7142 and AD7147 are integrated capacitance-to-digital converters
(CDCs) with on-chip environmental calibration for use in systems
requiring a novel user input method. The AD7142 and AD7147 can interface
to external capacitance sensors implementing functions such as buttons,
scrollwheels, sliders, touchpads and so on.

The chips don't restrict the specific usage. Depending on the hardware
connection, one special target board can include one or several these
components. The platform_data for the device's "struct device" holds
these information. The data-struct defined in head file descript the
hardware feature of button/scrollwheel/slider/touchpad components on
target boards, which need be filled in the arch/mach-/.

As the result, the driver is independent of boards. It gets the
components layout from the platform_data, registers related devices,
fullfills the algorithms and state machines for these components and
report related input events to up level.

Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

2 files changed, 64 insertions, 0 deletions

diff --git a/include/linux/input.h b/include/linux/input.h
index 7ed2251b33f1..83524e4f3290 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -806,6 +806,7 @@ struct input_absinfo {
 #define BUS_HOST                0x19
 #define BUS_GSC                 0x1A
 #define BUS_ATARI               0x1B
+#define BUS_SPI                 0x1C
 
 /*
  * MT_TOOL types
diff --git a/include/linux/input/ad714x.h b/include/linux/input/ad714x.h
new file mode 100644
index 000000000000..0cbe5e81482e
--- /dev/null
+++ b/include/linux/input/ad714x.h
@@ -0,0 +1,63 @@
+/*
+ * include/linux/input/ad714x.h
+ *
+ * AD714x is very flexible, it can be used as buttons, scrollwheel,
+ * slider, touchpad at the same time. That depends on the boards.
+ * The platform_data for the device's "struct device" holds this
+ * information.
+ *
+ * Copyright 2009 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#ifndef __LINUX_INPUT_AD714X_H__
+#define __LINUX_INPUT_AD714X_H__
+
+#define STAGE_NUM              12
+#define STAGE_CFGREG_NUM       8
+#define SYS_CFGREG_NUM         8
+
+/* board information which need be initialized in arch/mach... */
+struct ad714x_slider_plat {
+        int start_stage;
+        int end_stage;
+        int max_coord;
+};
+
+struct ad714x_wheel_plat {
+        int start_stage;
+        int end_stage;
+        int max_coord;
+};
+
+struct ad714x_touchpad_plat {
+        int x_start_stage;
+        int x_end_stage;
+        int x_max_coord;
+
+        int y_start_stage;
+        int y_end_stage;
+        int y_max_coord;
+};
+
+struct ad714x_button_plat {
+        int keycode;
+        unsigned short l_mask;
+        unsigned short h_mask;
+};
+
+struct ad714x_platform_data {
+        int slider_num;
+        int wheel_num;
+        int touchpad_num;
+        int button_num;
+        struct ad714x_slider_plat *slider;
+        struct ad714x_wheel_plat *wheel;
+        struct ad714x_touchpad_plat *touchpad;
+        struct ad714x_button_plat *button;
+        unsigned short stage_cfg_reg[STAGE_NUM][STAGE_CFGREG_NUM];
+        unsigned short sys_cfg_reg[SYS_CFGREG_NUM];
+};
+
+#endif