Commit Graph

15 Commits

Author SHA1 Message Date
Thomas Gleixner
4101ecc23d power: reset: ltc2952: Remove bogus hrtimer_start() return value checks
The return value of hrtimer_start() tells whether the timer was
inactive or active already when hrtimer_start() was called.

The code emits a bogus warning if the timer was active already
claiming that the timer could not be started.

Remove it along with the bogus comment in the else path.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Frans Klaver <frans.klaver@xsens.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-pm@vger.kernel.org
2015-04-23 14:38:01 +02:00
Frans Klaver
ee18185331 power: reset: ltc2952: make trigger input optional
Currently the ltc2952 supports only one button sequence to initiate
powerdown. This is not always desirable, as even prolonged button
presses can happen in use.

Allow ltc2952 users to pick their own power down sequence, by making the
trigger input optional. Since this still means that the ltc2952 may
power down the platform if the power button is pressed for about 5
seconds, we still need to make sure to start the watchdog toggle to
prolong the system power for as long as we need it.

This will still allow the system to control power using the kill signal.

Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-01-20 13:58:31 +01:00
Frans Klaver
c1ada2ff80 power: reset: ltc2952: check trigger value before starting timer
In ltc2952_poweroff_handler it is theoretically possible that the timer
fails to start on first pass (button press), but succeeds in starting on
the second (button release). This will cause the button press to be
misinterpreted, and will incorrectly shut down the system. Because a
picture says more than a thousand words:

Expected behavior:
tmr:      ++++++++++
btn: -----__________-----

Faulty behavior:
tmr:                +++++
btn: -----__________-----

Legend:
+ timer runs
_ button pressed
- button depressed

To prevent this from happening, check the value of the gpio before
starting the timer. If the button is active, we should start the timer,
else we should stop it.

The situation described can now still occur if the polarity of the input
pin is set incorrectly, but that at least is predictable behavior and
can be detected during the first tests.

Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-01-20 13:58:30 +01:00
Frans Klaver
2f6ea8ad73 power: reset: ltc2952: disable timers in _remove
Disable the timers when ltc2952_poweroff is removed. We don't want to
risk calling functions on data that no longer exist.

Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-01-20 13:58:30 +01:00
Frans Klaver
5689b786f7 power: reset: ltc2952: fix C++ style function pointers
The function pointers for the timers and pm_power_off are assigned with
C++ style
	foo = &func;

Let's change it instead to the more C style
	foo = func;

Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-01-20 13:58:30 +01:00
Frans Klaver
5c3faad29b power: reset: ltc2952: cleanup control flow in poweroff_handler
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: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-01-20 13:58:30 +01:00
Frans Klaver
0428c40d4c power: reset: ltc2952: drop empty suspend/resume functions
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: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-01-20 13:58:29 +01:00
Frans Klaver
818ca4c8c7 power: reset: ltc2952: remove global variable poweroff_panic
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: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-01-20 13:58:28 +01:00
Frans Klaver
a5f67be520 power: reset: ltc2952: reduce dependency on global variables
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: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-01-20 13:58:28 +01:00
Frans Klaver
62113b3117 power: reset: ltc2952: prefer devm_gpiod_get over gpiod_get
This reduces cleanup code and chance of errors.

Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-01-20 13:58:28 +01:00
Frans Klaver
f66472df69 power: reset: ltc2952: unroll gpio_desc array
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: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-01-20 13:58:28 +01:00
Frans Klaver
07d08237d3 power: reset: ltc2952: prefer devm_request_irq over request_irq
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: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-01-20 13:58:28 +01:00
Frans Klaver
0a5c6a2276 power: reset: ltc2952: prefer devm_kzalloc over kzalloc
Make use of the fact that the allocated resources can be automatically
deallocated. This reduces cleanup code and chance of leaks.

Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-01-20 13:58:27 +01:00
Wolfram Sang
5938ee2bb2 power: reset: drop owner assignment from platform_drivers
A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-10-20 16:21:28 +02:00
René Moll
6647156c00 power: reset: add LTC2952 poweroff driver
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: René Moll <rene.moll@xsens.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2014-09-16 11:01:39 +02:00