Input: add regulator haptic driver

This change adds support for haptic driver controlled by voltage of a
regulator. Userspace can control the device via Force Feedback interface
from input framework.

Signed-off-by: Jaewon Kim <jaewon02.kim@samsung.com>
Signed-off-by: Hyunhee Kim <hyunhee.kim@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Input: add new sun4i-lradc-keys driver

Allwinnner sunxi SoCs have a low resolution adc (called lradc) which is
specifically designed to have various (tablet) keys (ie home, back, search,
etc). attached to it using a resistor network. This adds a driver for this.

There are 2 channels, currently this driver only supports chan0 since there
are no boards known to use chan1.

This has been tested on an olimex a10s-olinuxino-micro, a13-olinuxino, and
a20-olinuxino-micro.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Input: add tps65218 power button driver

With this driver, we can report KEY_POWER on AM437x SK. This patch has been
tested with said board.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>