Input: sysrq - allow specifying alternate reset sequence

This patch adds keyreset functionality to the sysrq driver. It allows
certain button/key combinations to be used in order to trigger emergency
reboots.

Redefining the '__weak platform_sysrq_reset_seq' variable is required
to trigger the feature.  Alternatively keys can be passed to the driver
via a module parameter.

This functionality comes from the keyreset driver submitted by
Arve Hjønnevåg in the Android kernel.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Input: tegra-kbc - fix build warning

Fix the following build warning when building driver with CONFIG_PM_SLEEP
not selected.

tegra-kbc.c:360:13: warning: 'tegra_kbc_set_keypress_interrupt' defined but not used [-Wunused-function]

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Input: tegra-kbc - use devm_* for resource allocation

Use devm_* for memory, clock, irq, input device allocation. This reduces
code for freeing these resources.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Input: tegra-kbc - add support for rows/columns configuration from dt

The NVIDIA's Tegra KBC has maximum 24 pins to make matrix keypad.
Any pin can be configured as row or column. The maximum column pin
can be 8 and maximum row pin can be 16.

Remove the assumption that all first 16 pins will be used as row
and remaining as columns and Add the property for configuring pins
to either row or column from DT. Update the devicetree binding
document accordingly.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Input: tegra-kbc - remove default keymap

Tegra KBC driver have the default key mapping for 16x8 configuration.
The key mapping can be provided through platform data or through DT
and the mapping varies from platform to platform, hence this default
mapping is not so useful. Remove the default mapping to reduce the code
lines of the driver.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>