power: reset: ltc2952-poweroff: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231104211501.3676352-23-u.kleine-koenig@pengutronix.de
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: remove MODULE_LICENSE in non-modules

Since commit 8b41fc4454e ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf"), MODULE_LICENSE declarations
are used to identify modules. As a consequence, uses of the macro
in non-modules will cause modprobe to misidentify their containing
object file as a module when it is not (false positives), and modprobe
might succeed rather than failing with a suitable error message.

So remove it in the files in this commit, none of which can be built as
modules.

Signed-off-by: Nick Alcock <nick.alcock@oracle.com>
Suggested-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: linux-modules@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Hitomi Hasegawa <hasegawa-hitomi@fujitsu.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

power: reset: ltc2952: Fix use of floating point literals

A new commit in LLVM causes an error on the use of 'long double' when
'-mno-x87' is used, which the kernel does through an alias,
'-mno-80387' (see the LLVM commit below for more details around why it
does this).

drivers/power/reset/ltc2952-poweroff.c:162:28: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux-gnu' does not support it
data->wde_interval = 300L * 1E6L;
^
drivers/power/reset/ltc2952-poweroff.c:162:21: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux-gnu' does not support it
data->wde_interval = 300L * 1E6L;
^
drivers/power/reset/ltc2952-poweroff.c:163:41: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux-gnu' does not support it
data->trigger_delay = ktime_set(2, 500L*1E6L);
^
3 errors generated.

This happens due to the use of a 'long double' literal. The 'E6' part of
'1E6L' causes the literal to be a 'double' then the 'L' suffix promotes
it to 'long double'.

There is no visible reason for floating point values in this driver, as
the values are only assigned to integer types. Use NSEC_PER_MSEC, which
is the same integer value as '1E6L', to avoid changing functionality but
fix the error.

Fixes: 6647156c00cc ("power: reset: add LTC2952 poweroff driver")
Link: https://github.com/ClangBuiltLinux/linux/issues/1497
Link: https://github.com/llvm/llvm-project/commit/a8083d42b1c346e21623a1d36d1f0cadd7801d83
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: ltc2952: Use hrtimer_forward_now()

hrtimer_forward_now() provides the same functionality as the open coded
hrtimer_forward() invocation. Prepares for removal of hrtimer_forward()
from the public interfaces.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

kernel.h: split out panic and oops helpers

kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt to start cleaning it up by splitting out panic and
oops helpers.

There are several purposes of doing this:
- dropping dependency in bug.h
- dropping a loop by moving out panic_notifier.h
- unload kernel.h from something which has its own domain

At the same time convert users tree-wide to use new headers, although for
the time being include new header back to kernel.h to avoid twisted
indirected includes for existing users.

[akpm@linux-foundation.org: thread_info.h needs limits.h]
[andriy.shevchenko@linux.intel.com: ia64 fix]
Link: https://lkml.kernel.org/r/20210520130557.55277-1-andriy.shevchenko@linux.intel.com

Link: https://lkml.kernel.org/r/20210511074137.33666-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Co-developed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

power: reset: ltc2952: make trigger delay configurable

Make trigger delay configurable through device tree with
trigger-delay-ms property.

Trigger delay is the time to wait before starting shutdown
sequence after trigger line assertion.
Trigger delay must take into account the OFFT time configured
with the capacitor connected to OFFT pin of the LTC2952 chip.
Basically, the higher the capacitance connected to OFFT pin,
the larger trigger delay must be.

Signed-off-by: Marek Czerski <ma.czerski@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: ltc2952: remove unused variable

Fix gcc '-Wunused-but-set-variable' warning:
drivers/power/reset/ltc2952-poweroff.c:97:16: warning: variable
‘overruns’ set but not used [-Wunused-but-set-variable]
unsigned long overruns;

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Hongbo Yao <yaohongbo@huawei.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157

Based on 3 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [kishon] [vijay] [abraham]
[i] [kishon]@[ti] [com] this program is distributed in the hope that
it will be useful but without any warranty without even the implied
warranty of merchantability or fitness for a particular purpose see
the gnu general public license for more details

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [graeme] [gregory]
[gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
[kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
[hk] [hemahk]@[ti] [com] this program is distributed in the hope
that it will be useful but without any warranty without even the
implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

treewide: convert ISO_8859-1 text comments to utf-8

Almost all files in the kernel are either plain text or UTF-8 encoded. A
couple however are ISO_8859-1, usually just a few characters in a C
comments, for historic reasons.

This converts them all to UTF-8 for consistency.

Link: http://lkml.kernel.org/r/20180724111600.4158975-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Simon Horman <horms@verge.net.au> [IPVS portion]
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> [IIO]
Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Acked-by: Rob Herring <robh@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

headers: separate linux/mod_devicetable.h from linux/platform_device.h

At over 4000 #includes, <linux/platform_device.h> is the 9th most
#included header file in the Linux kernel. It does not need
<linux/mod_devicetable.h>, so drop that header and explicitly add
<linux/mod_devicetable.h> to source files that need it.

4146 #include <linux/platform_device.h>

After this patch, there are 225 files that use <linux/mod_devicetable.h>,
for a reduction of around 3900 times that <linux/mod_devicetable.h>
does not have to be read & parsed.

225 #include <linux/mod_devicetable.h>

This patch was build-tested on 20 different arch-es.

It also makes these drivers SubmitChecklist#1 compliant.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kbuild test robot <lkp@intel.com> # drivers/media/platform/vimc/
Reported-by: kbuild test robot <lkp@intel.com> # drivers/pinctrl/pinctrl-u300.c
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ktime: Cleanup ktime_set() usage

ktime_set(S,N) was required for the timespec storage type and is still
useful for situations where a Seconds and Nanoseconds part of a time value
needs to be converted. For anything where the Seconds argument is 0, this
is pointless and can be replaced with a simple assignment.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>

power: reset: ltc2952: use _optional variant of devm_gpiod_get

devm_gpiod_get_optional returns NULL if devm_gpiod_get would return an
ENOENT error pointer.

There is no semantic change intended.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

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.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Frans Klaver <frans.klaver@xsens.com>
Cc: "René Moll" <linux@r-moll.nl>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-pm@vger.kernel.org
Acked-by: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

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

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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>