ltc2952_poweroff_handler uses gotos to return from the function. Since
we don't do cleanups exiting this function, just return IRQ_HANDLED on
the spot and be done with it.

While at it, remove the variable 'ret'. It was never used very much.
Signed-off-by: NFrans Klaver <frans.klaver@xsens.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Documentation/SubmittingDrivers suggests these be implemented even when
they do nothing. On the other hand, the platform code calls these
functions 'legacy'. Suspend and resume operations should go into a
pm_ops structure, pointed at by the driver's pm field. This approach
would lead to a lot of boiler plate, while achieving nothing. Drop the
functions instead.
Signed-off-by: NFrans Klaver <frans.klaver@xsens.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

As per Documentation/CodingStyle ch.4, we should keep global variables
to a mininum. Move the panic state into the driver data, regardless of
whether panic is a system state or not.

This removes the need for the custom _init and _exit functions, so
replace them with a call to the module_platform_driver() macro.
Signed-off-by: NFrans Klaver <frans.klaver@xsens.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Documentation/CodingStyle ch.4 mentions in a side node that global
variables should only be used if you really need them. Reduce the use of
the global instance of ltc2952_poweroff so we may eventually remove it
entirely.

While at it, rename ltc2952_poweroff_data to ltc2952_poweroff, just to
save that little bit of typing.
Signed-off-by: NFrans Klaver <frans.klaver@xsens.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

This reduces cleanup code and chance of errors.
Signed-off-by: NFrans Klaver <frans.klaver@xsens.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

The three gpio's used by this driver are stored in an array of pointers.
This doesn't add much besides cleanups in a loop. In fact, it makes most
of the usage sites harder to read. Unroll the loop, and live with the
fact that cleanups become slightly larger.
Signed-off-by: NFrans Klaver <frans.klaver@xsens.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Make use of the fact that we allocated resources can be automatically
deallocated. This reduces cleanup code and chance of errors. It also
removes the need for the virq member of the ltc2952_poweroff_data
struct.
Signed-off-by: NFrans Klaver <frans.klaver@xsens.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Make use of the fact that the allocated resources can be automatically
deallocated. This reduces cleanup code and chance of leaks.
Signed-off-by: NFrans Klaver <frans.klaver@xsens.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

A platform_driver does not need to set an owner, it will be populated by the
driver core.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This adds a driver for the LTC2952, an external power control chip,
which signals the OS to shut down. Additionally this driver lets the
kernel power down the board.
Signed-off-by: NRené Moll <rene.moll@xsens.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>