HBRV-based default selection of backlight control strategy didn't work
well, at least the X41 defines it but doesn't use it and I don't think
it will stop there.
Switch to a white/blacklist. All models that have HBRV defined have
been included in the list, and initially all ATI GPUs will get
ECNVRAM, and the Intel GPUs will get UCMS_STEP.
Symptoms of incorrect backlight mode selection are:
1. Non-working backlight control through sysfs;
2. Backlight gets reset to the lowest level at every shutdown, reboot
and when thinkpad-acpi gets unloaded;
This fixes a regression in 2.6.30, bugzilla #13826
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Reported-by: Tobias Diedrich <ranma+kernel@tdiedrich.de>
Cc: stable@kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>
The standard ACPI dock driver can handle the hotplug bays and docks of
the ThinkPads just fine (including batteries) as of 2.6.27, and the
code in thinkpad-acpi for the dock and bay subdrivers is currently
broken anyway...
Userspace needs some love to support the two-stage ejection nicely,
but it is simple enough to do through udev rules (you don't even need
HAL) so this wouldn't justify fixing the dock and bay subdrivers,
either.
That leaves warm-swap bays (_EJ3) support for thinkpad-acpi, as well
as support for the weird dock of the model 570, but since such support
has never left the "experimental" stage, it is also not a strong
enough reason to find a way to fix this code.
Users of ThinkPads with warm-swap bays are urged to request that _EJ3
support be added to the regular ACPI dock driver, if such feature is
indeed useful for them.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
The setting of the "persistent" flag is also made more explicit using
a new rfkill_init_sw_state() function, instead of special-casing
rfkill_set_sw_state() when it is called before registration.
Suspend is a bit of a corner case so we try to get away without adding
another hack to rfkill-input - it's going to be removed soon.
If the state does change over suspend, users will simply have to prod
rfkill-input twice in order to toggle the state.
Userspace policy agents will be able to implement a more consistent user
experience. For example, they can avoid the above problem if they
toggle devices individually. Then there would be no "global state"
to get out of sync.
Currently there are only two rfkill drivers with persistent soft-blocked
state. thinkpad-acpi already checks the software state on resume.
eeepc-laptop will require modification.
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
CC: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Support reading the tachometer of the auxiliary fan of a X60/X61.
It was found out by sheer luck, that bit 0 of EC register 0x31
(formely HBRV) selects which fan is active for tachometer readings
through EC 0x84/0x085: 0 for fan1, 1 for fan2.
Many thanks to Christoph Kl??nter, to Whoopie, and to weasel, who
helped confirm that behaviour.
Fan control through EC HFSP applies to both fans equally, regardless
of the state of bit 0 of EC 0x31. That matches the way the DSDT uses
HFSP.
In order to better support the secondary fan, export a second
tachometer over hwmon, and add defensive measures to make sure we are
reading the correct tachometer.
Support for the second fan is whitelist-based, as I have not found
anything obvious to look for in the DSDT to detect the presence of
the second fan.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Forcing thinkpad-acpi to do EC-based brightness control (HBRV) on a
X61 has very... interesting effects, instead of doing nothing (since
it doesn't have EC-based backlight control), it causes "weirdness" in
the fan tachometer readings, for example.
This means the EC register that used to be HBRV has been reused by
Lenovo for something else, but they didn't remove it from the DSDT.
Make sure the documentation reflects this data, and forbid the user
from forcing the driver to access HBRV on Lenovo ThinkPads.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Make use of acpi_video_backlight_support() also in hotkey_init, to make
sure this doesn't happen:
thinkpad_acpi: This ThinkPad has standard ACPI backlight brightness
control, supported by the ACPI video driver
thinkpad_acpi: Disabling thinkpad-acpi brightness events by default...
thinkpad_acpi: Standard ACPI backlight interface not available,
thinkpad_acpi native brightness control enabled
thinkpad_acpi: detected a 16-level brightness capable ThinkPad
Note that this is purely cosmetic, there is absolutely _no_ change in
behaviour. Those events are sometimes enabled at runtime by userspace, but
the driver never enables them by itself unless someone messed with the
default keymaps.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Reported-by: Jochen Schulz <jrschulz@well-adjusted.de>
Signed-off-by: Len Brown <len.brown@intel.com>
Add support for extra LEDs on recent ThinkPads, and avoid registering
with the led class the LEDs which are not available for a given
ThinkPad model.
All non-restricted LEDs are always available through the procfs
interface, as the firmware doesn't care if an attempt is made to
access an invalid LED.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Some ThinkPads want two arguments for BEEP, while others want just
one, causing ACPICA to log warnings like this:
ACPI Warning (nseval-0177): Excess arguments - method [BEEP] needs 1,
found 2 [20080926]
Deal with it.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Add a quirklist engine suitable for matching ThinkPad firmware,
and change the code to use it.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Extend the thinkpad model and firmware identification data with the
release serial number for the BIOS and firmware (when available), as
that is easier to parse and compare than the version strings.
We're going to greatly extend the use of the ThinkPad DMI data through
quirk lists, so it is best to be quite strict and make sure what we
get from DMI is exactly what we expect, otherwise quirk matching may
result in quite insane things.
IBM (and Lenovo, at least for the ThinkPad line) uses this schema for
firmware versioning and model:
Firmware model: Two digits, [0-9A-Z]
Firmware version: AABBCCDD, where
AA = firmware model, see above
BB = "ET" for BIOS, "HT" for EC
CC = release version, two digits, [0-9A-Z],
"00" < "09" < "0A" < "10" < "A0" < "ZZ"
DD = "WW"
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
rfkill_set_global_sw_state() (previously rfkill_set_default()) will no
longer be exported by the rewritten rfkill core.
Instead, platform drivers which can provide persistent soft-rfkill state
across power-down/reboot should indicate their initial state by calling
rfkill_set_sw_state() before registration. Otherwise, they will be
initialized to a default value during registration by a set_block call.
We remove existing calls to rfkill_set_sw_state() which happen before
registration, since these had no effect in the old model. If these
drivers do have persistent state, the calls can be put back (subject
to testing :-). This affects hp-wmi and acer-wmi.
Drivers with persistent state will affect the global state only if
rfkill-input is enabled. This is required, otherwise booting with
wireless soft-blocked and pressing the wireless-toggle key once would
have no apparent effect. This special case will be removed in future
along with rfkill-input, in favour of a more flexible userspace daemon
(see Documentation/feature-removal-schedule.txt).
Now rfkill_global_states[n].def is only used to preserve global states
over EPO, it is renamed to ".sav".
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch completely rewrites the rfkill core to address
the following deficiencies:
* all rfkill drivers need to implement polling where necessary
rather than having one central implementation
* updating the rfkill state cannot be done from arbitrary
contexts, forcing drivers to use schedule_work and requiring
lots of code
* rfkill drivers need to keep track of soft/hard blocked
internally -- the core should do this
* the rfkill API has many unexpected quirks, for example being
asymmetric wrt. alloc/free and register/unregister
* rfkill can call back into a driver from within a function the
driver called -- this is prone to deadlocks and generally
should be avoided
* rfkill-input pointlessly is a separate module
* drivers need to #ifdef rfkill functions (unless they want to
depend on or select RFKILL) -- rfkill should provide inlines
that do nothing if it isn't compiled in
* the rfkill structure is not opaque -- drivers need to initialise
it correctly (lots of sanity checking code required) -- instead
force drivers to pass the right variables to rfkill_alloc()
* the documentation is hard to read because it always assumes the
reader is completely clueless and contains way TOO MANY CAPS
* the rfkill code needlessly uses a lot of locks and atomic
operations in locked sections
* fix LED trigger to actually change the LED when the radio state
changes -- this wasn't done before
Tested-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> [thinkpad]
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Plenty of high-profile changes, so it deserves a new version number.
Features added since 0.22:
* Restrict unsafe LEDs
* New race-less brightness control strategy for IBM ThinkPads
* Disclose TGID of driver access from userspace (debug)
* Warn when deprecated functions are used
Other changes:
* Better debug messages in some subdrivers
* Removed "hotkey disable" support, since it breaks the driver
* Dropped "ibm-acpi" alias
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Simplify the module autoloading a great deal, by keying to the HID for
the HKEY interface.
Only _really_ ancient IBM ThinkPad models like the 240, 240x and 570
lack the HKEY interface, and they're getting their own trimmed-down
driver one of these days.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Fix the module to use one instance of MODULE_AUTHOR per author.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
The set_blink hook code in the LED subdriver would never manage to get
a LED to blink, and instead it would just turn it on. The consequence
of this is that the "timer" trigger would not cause the LED to blink
if given default parameters.
This problem exists since 2.6.26-rc1.
To fix it, switch the deferred LED work handling to use the
thinkpad-acpi-specific LED status (off/on/blink) directly.
This also makes the code easier to read, and to extend later.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: stable@kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>
Avoid the WARN() when the procfs handler for hotkey enable is used by
a module parameter. Instead, urge the user to stop doing that.
Reported-by: Niel Lambrechts <niel.lambrechts@gmail.com>
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Refactor and redesign the brightness control backend...
In order to fix bugzilla #11750...
Add a new brightness control mode: support direct NVRAM checkpointing
of the backlight level (i.e. store directly to NVRAM without the need
for UCMS calls), and use that together with the EC-based control.
Disallow UCMS+EC, thus avoiding races with the SMM firmware.
Switch the models that define HBRV (EC Brightness Value) in the DSDT
to the new mode. These are: T40-T43, R50-R52, R50e, R51e, X31-X41.
Change the default for all other IBM ThinkPads to UCMS-only. The
Lenovo models already default to UCMS-only.
Reported-by: Alexey Fisher <bug-track@fisher-privat.net>
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Enhance debugging messages for the fan subdriver.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Enhance debugging messages for the hotkey subdriver.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Enhance debugging messages for all rfkill subdrivers in thinkpad-acpi.
Also, log a warning if the deprecated sysfs attributes are in use.
These attributes are going to be removed sometime in 2010.
There is an user-visible side-effect: we now coalesce attempts to
enable/disable bluetooth or WWAN in the procfs interface, instead of
hammering the firmware with multiple requests.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Some of the ThinkPad LEDs indicate critical conditions that can cause
data loss or cause hardware damage when ignored (e.g. force-ejecting
a powered up bay; ignoring a failing battery, or empty battery; force-
undocking with the dock buses still active, etc).
On almost all ThinkPads, LED access is write-only, and the firmware
usually does fire-and-forget signaling on them, so you effectively
lose whatever message the firmware was trying to convey to the user
when you override the LED state, without any chance to restore it.
Restrict access to all LEDs that can convey important alarms, or that
could mislead the user into incorrectly operating the hardware. This
will make the Lenovo engineers less unhappy about the whole issue.
Allow users that really want it to still control all LEDs, it is the
unaware user that we have to worry about.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
The HKEY disable functionality basically cripples the entire event
model of the ThinkPad firmware and of the thinkpad-acpi driver.
Remove this functionality from the driver. HKEY must be enabled at
all times while thinkpad-acpi is loaded, and disabled otherwise.
For sysfs, according to the sysfs ABI and the thinkpad-acpi sysfs
rules of engagement, we will just remove the attributes. This will be
done in two stages: disable their function now, after two kernel
releases, remove the attributes.
For procfs, we call WARN(). If nothing triggers it, I will simply
remove the enable/disable commands entirely in the future along with
the sysfs attributes.
I don't expect much, if any fallout from this. There really isn't any
reason to mess with hotkey_enable or with the enable/disable commands
to /proc/acpi/ibm/hotkey, and this has been true for years...
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Add a debug helper that discloses the TGID of the userspace task
attempting to access the driver. This is highly useful when dealing
with bug reports, since often the user has no idea that some userspace
application is accessing thinkpad-acpi...
Also add a helper to log warnings about sysfs attributes that are
deprecated.
Use the new helpers to issue deprecation warnings for bluetooth_enable
and wwan_enabled, that have been deprecated for a while, now.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Add missing log levels in a standalone commit, to avoid dependencies in
future unrelated changes, just because they wanted to use one of the
missing log levels.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Fix the vdbg_printk macro definition to be sane when
CONFIG_THINKPAD_ACPI_DEBUG is undefined, and move the mess into a file
section of its own.
This doesn't change anything in the current code, but future code will
need the proper behaviour.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
The driver was renamed two years ago, on 2.6.21. Drop the old
compatibility alias, we have given everybody quite enough time
to update their configs to the new name.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (28 commits)
trivial: Update my email address
trivial: NULL noise: drivers/mtd/tests/mtd_*test.c
trivial: NULL noise: drivers/media/dvb/frontends/drx397xD_fw.h
trivial: Fix misspelling of "Celsius".
trivial: remove unused variable 'path' in alloc_file()
trivial: fix a pdlfush -> pdflush typo in comment
trivial: jbd header comment typo fix for JBD_PARANOID_IOFAIL
trivial: wusb: Storage class should be before const qualifier
trivial: drivers/char/bsr.c: Storage class should be before const qualifier
trivial: h8300: Storage class should be before const qualifier
trivial: fix where cgroup documentation is not correctly referred to
trivial: Give the right path in Documentation example
trivial: MTD: remove EOL from MODULE_DESCRIPTION
trivial: Fix typo in bio_split()'s documentation
trivial: PWM: fix of #endif comment
trivial: fix typos/grammar errors in Kconfig texts
trivial: Fix misspelling of firmware
trivial: cgroups: documentation typo and spelling corrections
trivial: Update contact info for Jochen Hein
trivial: fix typo "resgister" -> "register"
...
Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.
We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.
But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.
->read_proc/->write_proc were just fixed to not require ->owner for
protection.
rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.
Removing ->owner will also make PDE smaller.
So, let's nuke it.
Kudos to Jeff Layton for reminding about this, let's say, oversight.
http://bugzilla.kernel.org/show_bug.cgi?id=12454
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Looking at the source, there seems to be a missing * to match my DMI
string. I mean for newer IBM and Lenovo's laptops you match either one
of the following:
MODULE_ALIAS("dmi:bvnIBM:*:svnIBM:*:pvrThinkPad*:rvnIBM:*");
MODULE_ALIAS("dmi:bvnLENOVO:*:svnLENOVO:*:pvrThinkPad*:rvnLENOVO:*");
While for older Thinkpads, you do this (for instance):
IBM_BIOS_MODULE_ALIAS("1[0,3,6,8,A-G,I,K,M-P,S,T]");
with IBM_BIOS_MODULE_ALIAS being MODULE_ALIAS("dmi:bvnIBM:bvr" __type "ET??WW")
Note there's no * terminating the string. As result, udev doesn't load
anything because modprobe cannot find anything matching this (my
machine actually):
udevtest: run: '/sbin/modprobe dmi:bvnIBM:bvr1IET71WW(2.10):bd06/16/2006:svnIBM:pn236621U:pvrNotAv
Signed-off-by: Mathieu Chouquet-Stringer <mchouque@free.fr>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
It is about time to bump up the version.
Features added since 0.21: fan suspend/resume support, preserve radio
state across power off (for some radio types), built-in UWB radio
rfkill support and thermal alarm events support.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
HKEY event 0x6030 is a helper for Lenovo's Advanced Thermal Management
Windows driver, which is, of course, completely undocumented.
Silence any warnings about it being an unknown alarm, and report it
unmodified for userspace.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Better document the Unitialized HFSP quirk, and modularize it a bit.
This makes the code flow easier to read and reduces LOC.
Apply the Unitialized HFSP closer to the source (i.e. inside the
get_fan_status()), this fixes a harmless buglet where at driver init
with the quirk active, the user could set the hwmon pwm1 attribute and
switch out of pwm1_mode=2 to pwm1_mode=0 without changing pwm1_mode
directly.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Tino Keitel <tino.keitel@tikei.de>
Signed-off-by: Len Brown <len.brown@intel.com>
Ask users to tell us about any unhandled events they find.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Handle some HKEY events that are actually firmware alarms. For
now, we do the simple thing: log specific messages to the log and let
the thinkpad-specific event pass to userspace.
In the future, these events will be migrated to generic notifications
and subsystems.
These alarms are NOT available on all ThinkPads. E.g. the T43 only
issues 0x6011 and 0x6012.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Clean up the hotkey_notify() handler, which handles the HKEY notifications
from the ACPI firmware. It was getting too long and deep.
No functional changes.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Unfortunately, POSIX in all of its braindamage, do not state that userspace has
to deal with EINTR in read/write and friends... so, lesser code just doesn't.
Switch from *_interruptible to *_killable on the sysfs- and procfs-related
mutexes. This closes this possible can of worms.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Add rfkill support for USB UWB radio devices on very recent ThinkPad
laptop models.
The new subdriver is moslty a trimmed down copy of the wwan subdriver.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Store in firmware NVRAM the radio state on machine shutdown for WWAN and
bluetooth. Also, try to set the initial boot state of these radios as the
rfkill default state for their respective classes.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Instruct the firmware to not enable the radios when resuming. This
is safer, and the rfkill core will take care to manually enable any
radios that need to be enabled.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
This code is required to keep the thinkpad-acpi maintainer sane, and
it is disabled by default.
Add a debug facility to simulate an rfkill hardware rocker switch, a
bluetooth rfkill soft-switch, a WWAN rfkill soft-switch on thinkpads.
The simulated switches obviously do not kill any radios in hardware or
firmware (unlike the real one). They also don't issue deprecated proc
events.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Move x86 platform specific drivers from drivers/misc/
to a new home under drivers/platform/x86/.
The community has been maintaining x86 vendor-specific
platform specific drivers under /drivers/misc/ for a few years.
The oldest ones started life under drivers/acpi.
They moved out of drivers/acpi/ because they don't actually
implement the ACPI specification, but either simply
use ACPI, or implement vendor-specific ACPI extensions.
In the future we anticipate...
drivers/misc/ will go away.
other architectures will create drivers/platform/<arch>
Signed-off-by: Len Brown <len.brown@intel.com>