Input: add generic input driver to read encoded GPIO lines

Add a driver to read group of GPIO lines and provide its status as a
numerical value as input event to the system. This will help in
interfacing devices, that can be connected over GPIOs, that provide
input to the system by driving GPIO lines connected to them like a
rotary dial or a switch.

For example, a rotary switch can be connected to four GPIO lines. The
status of the GPIO lines reflect the actual position of the rotary
switch dial. For example, if dial points to 9, then the four GPIO lines
connected to the switch will read HLLH(0b'1001 = 9). This value
can be reported as an ABS_* event to the input subsystem.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index efb0ca871327..7cdb89397d18 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -292,6 +292,18 @@ config INPUT_GPIO_TILT_POLLED
 	  To compile this driver as a module, choose M here: the
 	  module will be called gpio_tilt_polled.
 
+config INPUT_GPIO_DECODER
+	tristate "Polled GPIO Decoder Input driver"
+	depends on GPIOLIB || COMPILE_TEST
+	select INPUT_POLLDEV
+	help
+	 Say Y here if you want driver to read status of multiple GPIO
+	 lines and report the encoded value as an absolute integer to
+	 input subsystem.
+
+	 To compile this driver as a module, choose M here: the module
+	 will be called gpio_decoder.
+
 config INPUT_IXP4XX_BEEPER
 	tristate "IXP4XX Beeper support"
 	depends on ARCH_IXP4XX