Add const to rfkill_ops structures that are only passed as an argument
to the functions rfkill_alloc or samsung_new_rfkill. These arguments are
of type const, so such structures can be annotated with const.
Signed-off-by: NBhumika Goyal <bhumirks@gmail.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>

Add copyright statements for Andy Lutomirski and Darren Hart (VMware)
for their contributions to the WMI bus infrastructure and the creation
of the wmi-bmof driver.
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>

If a machine reports a RF Button in the communication button device
bitmap, we need to remove it before calling Get Device Status otherwise
it will return the "Undefined device" (0xE2) error code.

Although this may be a BIOS bug, we don't really need to get or set the
RF Button status. The status indicator LED embedded in the button is
controlled by firmware logic, depending on the status of the wireless
radios present on the machine (WiFi || WWAN).

This commit fixes the wireless status indicator LED on the Acer
TravelMate P648-G2-MG, and cleans the following message from the kernel
log: "Get Current Device Status failed: 0xe2 - 0x0".
Signed-off-by: NJoão Paulo Rechi Vita <jprvita@endlessm.com>
Reviewed-by: N"Lee, Chun-Yi" <joeyli.kernel@gmail.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>

The struct pcc_keyinput is not used in panasonic-laptop and in
anywhere in kernel, and it can be removed.
Signed-off-by: NAlex Hung <alex.hung@canonical.com>
Acked-by: NHarald Welte <laforge@gnumonks.org>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>

The variable is used uninitialized which might come into unexpected
behaviour on some Samsung laptops.

Initialize it to 0xffff which seems a proper value for non-supported
feature.
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>

Move some initialization out of _init and into _probe.
Update signatures and logic to use the wmi bus and device structures.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
[dvhart: drop deprecated sparse_keymap_free, order declarations, add commit msg]
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

Many laptops (and maybe servers?) have embedded WMI Binary MOF metadata.
We do not yet have open-source tools for processing the data, although
one is in the works thanks to Pali:

	https://github.com/pali/bmfdec

There is currently no interface to get the data in the first place. By
exposing it, we facilitate the development of new tools.

This is based on the original work of Andy Lutomirski <luto@kernel.org>,
but contains several modifications in response to various reviews.
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>

The Microsoft WMI documentation requires all data blocks to implement
the Query Control Method (WQxx). If we encounter a data block not
implementing this control method, issue a warning, and ignore the data
block. Remove the "readable" attribute as all data blocks must be
readable (query-able).

Be consistent with the language in the documentation, replace the
"writable" attribute with "setable".

Simplify (flatten) the control flow of wmi_create_device a bit while
we are updating it for the above changes.
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Some subdrivers need to access sibling devices. This gives them a
clean way to do so.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

We already have the PNP glue to instantiate platform devices for the
ACPI devices that WMI drives. WMI should therefore attach to the
platform device, not the ACPI node.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

wmi_query_block is unnecessarily indirect. Add a straightforward
method for wmi bus drivers to use to read block data.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

As a platform driver, acpi_driver.notify will not be available,
so use acpi_install_notify_handler as we will be converting to a
platform driver.

This gives event drivers a simple way to handle events. It
also seems closer to what the Windows docs suggest that Windows
does: it sounds like, in Windows, the mapper is responsible for
called _WED before dispatching to the subdriver.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
[dvhart: merge two development commits and update commit message]
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

At some point, we will want sub-drivers to get references to other
devices on the same WMI bus. This change is needed to avoid races.

This ends up simplifying the setup code and fixing some leaks, too.

This is based on the original work of Andy Lutomirski <luto@kernel.org>,
but includes several modifications, many in response to review from
Michał Kępień <kernel@kempniu.pl>:

  https://www.spinics.net/lists/platform-driver-x86/msg08201.htmlSigned-off-by: NDarren Hart (VMware) <dvhart@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The Dell XPS 13 9350 has one RW data object, one RO data object, and one
totally inaccessible data object. Check for the existence of the
accessor methods and report in sysfs.

The docs also permit WQxx getters for single-instance objects to
take no parameters. Probe for that as well to avoid ACPICA warnings
about mismatched signatures.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

Divide the "data", "method" and "event" types. All devices get
"instance_count" and "expensive" attributes, data and method devices get
"object_id" attributes, and event devices get "notify_id" attributes.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

We have two memory leaks. If guid_already_parsed returned true, we leak
the wmi_block. If wmi_create_device failed, we leak the device.

Simplify the logic and fix both of them.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

WMI is logically a bus: the WMI driver binds to an ACPI node (or
more than one), and each instance of the WMI driver enumerates its
children and hopes that drivers will attach to the children that are
useful.

This patch gives WMI a driver model bus type and the ability to
match to drivers. The bus itself is a device in the new "wmi_bus"
class, and all of the individual WMI devices are slotted into the
device hierarchy correctly.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

Currently we free all devices when we detach from any ACPI node.
Instead, keep track of which node WMI devices are attached to and
free them only as needed. While we are at it, match up notifications
with the device they came from correctly.

This will make our behavior more straightforward on systems with
more than one WMI node in the ACPI tables (e.g. the Dell XPS 13
9350).

This also adds a warning when GUIDs are not unique.

NB: The guid_string parameter in guid_already_parsed was a
little-endian binary GUID, not a string.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

Rearrange acpi_wmi_add to use Linux's error handling conventions.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

We will need the device to convert to a bus architecture and bind WMI to
the platform device.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

WMI is just a driver. There is no need to announce when it is loaded.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

According to Mario at Dell, the DELLABC6 device should not be used on a
Linux system. It also conflicts with Intel-HID and its interactions with
Network Manager. Document that we are aware of the device, but that we
are intentionally ignoring it.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
[dvhart: New commit message and minor comment wording fixes]
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: "Pali Rohár" <pali.rohar@gmail.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

This is based on Mario's explanation and observation of my laptop.
Suggested-by: N"Pali Rohár" <pali.rohar@gmail.com>
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

The hotkey table is 0xb2, add a comment for clarity.
Suggested-by: NDarren Hart <dvhart@infradead.org>
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Reviewed-by: NPali Rohár <pali.rohar@gmail.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

To avoid using module-wide data in remaining module code, employ
acpi_driver_data() and dev_get_drvdata() to fetch device-specific data
to work on in each function.  This makes the input local variables in
hotkey-related callbacks and the module-wide struct fujitsu_laptop
redundant, so remove them.  Adjust whitespace to make checkpatch happy.
Signed-off-by: NMichał Kępień <kernel@kempniu.pl>
Reviewed-by: NJonathan Woithe <jwoithe@just42.net>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

In order to perform their duties, all LED callbacks need a pointer to
the struct acpi_device representing the FUJ02E3 ACPI device.  To limit
the use of the module-wide pointer, the same pointer should be extracted
from data that gets passed to LED callbacks as arguments.  However, LED
core does not currently support supplying driver-specific pointers to
struct led_classdev callbacks, so the latter have to be implemented a
bit differently than backlight device callbacks and platform device
attribute callbacks.  As the FUJ02E3 ACPI device is the parent device of
all LED class devices registered by fujitsu-laptop, struct acpi_device
representing the former can be extracted by following the parent link
present inside the struct device belonging to the struct led_classdev
passed as an argument to each LED callback.

To get rid of module-wide structures defining LED class devices,
allocate them dynamically using devm_kzalloc() and initialize them in
acpi_fujitsu_laptop_leds_register().
Signed-off-by: NMichał Kępień <kernel@kempniu.pl>
Reviewed-by: NJonathan Woithe <jwoithe@just42.net>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

Prepare for not using module-wide data in call_fext_func() by explicitly
passing it a pointer to struct acpi_device while still using a
module-wide pointer in each call.

Doing this enables call_fext_func() to fetch the ACPI handle from its
argument, making the acpi_handle field of struct fujitsu_laptop useless,
so remove that field.  While we are at it, the dev field of the same
structure is assigned in acpi_fujitsu_laptop_add() but not used for
anything, so remove it as well.
Signed-off-by: NMichał Kępień <kernel@kempniu.pl>
Reviewed-by: NJonathan Woithe <jwoithe@just42.net>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

fujitsu-laptop registers two ACPI drivers: one for ACPI device FUJ02B1
enabling backlight control and another for ACPI device FUJ02E3 which
handles various other stuff (hotkeys, LEDs, etc.)  In a perfect world,
private data used by each of these drivers would be neatly encapsulated
in a structure specific to a given driver instance.  Sadly, firmware
present on some Fujitsu laptops makes that impossible by exposing
backlight power control (which is what the FUJ02B1 ACPI device should
take care of) through the FUJ02E3 ACPI device.  This means the backlight
driver needs a way to access an ACPI device it is not bound to.  When
the backlight driver is extracted into a separate module, it will not be
able to rely on a module-wide variable any more and such access will
happen through an API exposed by fujitsu-laptop.

For all known firmwares out in the wild, it seems that whenever the
FUJ02B1 ACPI device is present, it is always accompanied by a single
instance of the FUJ02E3 ACPI device.  We could independently grab an
ACPI handle to the FUJ02E3 ACPI device from the backlight driver, but
that would require using a hardcoded absolute path to that ACPI device,
which is subject to change.  It is easier to simply store a module-wide
pointer to the last (most likely only) FUJ02E3 ACPI device found, make
the aforementioned API use it and cover our bases by warning the user if
firmware exposes multiple FUJ02E3 ACPI devices.

Introducing this pointer in advance allows us to get rid of the
acpi_handle field of struct fujitsu_bl and also enables a bit more
step-by-step migration to a device-specific implementation of
call_fext_func().
Signed-off-by: NMichał Kępień <kernel@kempniu.pl>
Reviewed-by: NJonathan Woithe <jwoithe@just42.net>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

Only allocate memory for struct fujitsu_laptop when the FUJ02E3 ACPI
device is present.  Use devm_kzalloc() for allocating memory to simplify
cleanup.
Signed-off-by: NMichał Kępień <kernel@kempniu.pl>
Reviewed-by: NJonathan Woithe <jwoithe@just42.net>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

To prevent using module-wide data in backlight-related code, employ
acpi_driver_data() and bl_get_data() where possible to fetch
device-specific data to work on in each function.  This makes the input
local variable in acpi_fujitsu_bl_notify() and the acpi_handle field of
struct fujitsu_bl redundant, so remove them.
Signed-off-by: NMichał Kępień <kernel@kempniu.pl>
Reviewed-by: NJonathan Woithe <jwoithe@just42.net>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

Only allocate memory for struct fujitsu_bl when the FUJ02B1 ACPI device
is present.  Use devm_kzalloc() for allocating memory to simplify
cleanup.

Due to the fact that the power property of the backlight device created
by the backlight driver is accessed from acpi_fujitsu_laptop_add(),
pointer to the allocated memory will remain stored in a module-wide
variable until the backlight driver is extracted into a separate module.
Signed-off-by: NMichał Kępień <kernel@kempniu.pl>
Reviewed-by: NJonathan Woithe <jwoithe@just42.net>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

In portions of the driver which use device-specific data, rename local
variables from fujitsu_bl and fujitsu_laptop to priv in order to clearly
distinguish these parts from code that uses module-wide data.
Signed-off-by: NMichał Kępień <kernel@kempniu.pl>
Reviewed-by: NJonathan Woithe <jwoithe@just42.net>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

Devices with the intel_cht_int33fe ACPI device use a max17047 fuel-gauge
combined with a bq24272i charger, in order for the fuel-gauge driver to
correctly display charging / discharging status it needs to know which
charger is supplying the battery.

This commit sets the supplied-from device property to the name of the
bq24272i charger for this.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>

The function is currently not used, however it is part of the API and
might be used in the future. Adding the attribute fixes the following
warning when building with clang:

    drivers/platform/x86/intel_pmc_ipc.c:189:18: error: unused function
        'ipc_data_readb' [-Werror,-Wunused-function]
Signed-off-by: NMatthias Kaehlcke <mka@chromium.org>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>

Don't simply throw this to userspace via the sparse_keymap (which does not
have a mapping for scancode 1), as this causes KEY_UNKNOWN to be emitted,
which is a nuisance and of no use at all (it is not the right way to expose
this ACPI event to userspace, anyway, and the original intention of the commit
which added this (cfee5d63) was only to suppress
an unhandled event log message).
Signed-off-by: NHao Wei Tee <angelsl@angelsl.xyz>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>

A readonly sysfs property must not have a 'store' function:

drivers/platform/x86/ideapad-laptop.c:438:16: error: 'touchpad_store' defined but not used [-Werror=unused-function]

We can either comment it out or remove the function entirely,
without a good reason one or or another I picked the second option.

Fixes: 7f363145 ("platform/x86: ideapad-laptop: Switch touchpad attribute to be RO")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>

The latest Topstar BIOS updates (109_931P) advertise the "TPS0001"
device id by default, preventing the topstar-laptop module from being
loaded automatically.
Signed-off-by: NGuillaume Douézan-Grard <gdouezangrard@gmail.com>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

PEAQ is a new European OEM, I've bought one of their 2-in-1 x86 devices,
which is actually quite a nice device. Under Windows it has Dolby
software for "better" sound and you can select different equalizer
presets using a special button.

This WMI interface for this button is not really nice, as it does not do
notifies (it really does not I triple checked), but since I had already
figured out the entire WMI interface for this I decided to go the full
mile anyway and implement a WMI based input driver for this using
input_polldev since, well, we need to poll.

This commit adds support for this button making it report KEY_SOUND
input events. KEY_SOUND is already used in various places to switch
sound into theatre mode and things like that so it seems appropriate
here.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
[dvhart: minor declaration ordering and commit log typo fixes]
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

As per discussion [1] there are only few users of module_param_call() in
kernel which prevent to read module parameters back.

It thinkpad_acpi driver there is even no method do so. Thus, for now,
add just a comment to explain why 0 is used as permissions in
module_param_call().

[1]: https://patchwork.ozlabs.org/patch/713245/

Cc: Richard Weinberger <richard.weinberger@gmail.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>

There is no point to keep string literal split. It even makes slightly
harder to maintain and debug.

Join string literals back to be oneliners.

While here, print negative error without changing a sign as it is a
common pattern in the kernel.

Other than above there were no functional changes intended.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>