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: NAlexey Fisher <bug-track@fisher-privat.net>
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Enhance debugging messages for the fan subdriver.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Enhance debugging messages for the hotkey subdriver.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen 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: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen 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: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen 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: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen 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: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Some cleanups to the documentation of the driver.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen 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: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen 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: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Update documentation to reflect the new location of the
thinkpad-acpi driver.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

It is always "an" if there is a vowel _spoken_ (not written).
So it is:
"an hour" (spoken vowel)
but
"a uniform" (spoken 'j')
Signed-off-by: NFrederik Schwarzer <schwarzerf@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Put some information (and pointers to more) into the kernel's doc tree,
describing briefly the interface to the kernel's disk head unloading
facility. Information about how to set up a complete shock protection
system under GNU/Linux can be found on the web and is referenced
accordingly.

v3:
Here is some final polish including various spelling corrections
pointed out by Grant Grundler and Peter Moulder. Also, I have added some
information about the timing constraints related to disk head parking.
The patch looks more impressive than it really is and I think it would
be alright just to incorporate it into the original patch so as not to
clutter up the git log.
Signed-off-by: NElias Oltmanns <eo@nebensachen.de>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

These are now replaced by the rfkill interface.
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NLen Brown <len.brown@intel.com>

The WWAN radio control has been working well for over three years,
and is no longer experimental.
Signed-off-by: NJeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

rfkill support deserves a new version checkpoint...
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>

Add a read/write rfkill interface to the bluetooth radio switch on the
bluetooth submodule, and one for the wireless wan radio switch to the wan
submodule.

Since rfkill does care for when a switch changes state, use WLSW
notifications to also check if the WWAN or Bluetooth switches did not
change state (due to them being slaves of WLSW in firmware/hardware, but
that reality not being always properly exported by the thinkpad firmware).
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ivo van Doorn <IvDoorn@gmail.com>
Cc: John W. Linville <linville@tuxdriver.com>

This should have been removed when the colour was removed from the LED
device name.
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

Rename SW_RADIO to SW_RFKILL_ALL in thinkpad-acpi code and docs, following
5adad013 "Input: rename SW_RADIO to
SW_RFKILL_ALL".
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Full LED sysfs support, and the rest of the assorted minor fixes and
enhancements are a good reason to checkpoint a new version...
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Change all occourences of the "led" word to full uppercase in user
documentation.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Add a sysfs led class interface to the led subdriver.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: NLen Brown <len.brown@intel.com>

Add a sysfs led class interface to the thinklight (light subdriver).
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: NLen Brown <len.brown@intel.com>

Unfortunately, a lot of stuff in the kernel has size limitations, so
"thinkpad-acpi" ends up eating up too much real estate.  We were using
"tpacpi" in symbols already, but this shorthand was not visible to
userland.

Document that the driver will use tpacpi as a short hand where necessary,
and use it to name the kernel thread for NVRAM polling (now named
"ktpacpi_nvramd").

Also, register a module alias with the shorthand.  One can refer to the
module using the shorthand name.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Lenovo ThinkPads with generic ACPI backlight level control can be easily
set to react to keyboard brightness key presses in a more predictable way
than what they do when in "DOS / bootloader" mode after Linux brings
up the ACPI interface.

The switch to the ACPI backlight mode in the firmware is designed to be
safe to use only as an one way trapdoor.  One is not to force the firmware
to switch back to "DOS/bootloader" mode except by rebooting.  The mode
switch itself is performed by calling any of the ACPI _BCL methods at least
once.

When in ACPI mode, the backlight firmware just issues (standard) events for
the brightness up/down hot key presses along with the non-standard HKEY
events which thinkpad-acpi traps, and doesn't touch the hardware.

thinkpad-acpi will:

1. Place the ThinkPad firmware in ACPI backlight control mode
   if one is available
2. Suppress HKEY backlight change notifications by default
   to avoid double-reporting when ACPI video is loaded when
   the ThinkPad is in ACPI backlight control mode
3. Urge the user to load the ACPI video driver

The user is free to use either the ACPI video driver to get the brightness
key events, or to override the thinkpad-acpi default hotkey mask to get
them from thinkpad-acpi as well (this will result in duplicate events if
ACPI video is loaded, so let's hope distros won't screw this up).

Provided userspace is sane, all should work (and *keep* working), which is
more that can be said about the non-ACPI mode of the new Lenovo ThinkPad
BIOSes when coupled to current userspace and X.org drivers.

Full guidelines for backlight hot key reporting and use of the
thinkpad-acpi backlight interface have been added to the documentation.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Thomas Renninger <trenn@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Cc: <Larry.Finger@lwfinger.net>
Cc: <stefano.brivio@polimi.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NLen Brown <len.brown@intel.com>

Move laptop-mode.txt into the laptops/ sub-directory to consolidate
laptop doc files there.

Update references to the file's location.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

The mail LED name for acer-wmi currently hardcodes in the colour as green.
This is wrong, since many of the newer laptops now come with an orange
LED, and we have no way of telling what colour is used on a given system.

Also, rename the mail LED to be inline with the current recommendations of
the LED class documentation.
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NLen Brown <len.brown@intel.com>

A quick study of the 0x5009/0x500A HKEY event on the X61t DSDT revealed the
existence of the EC HTAB register (EC 0x0f, bit 7), and a compare with the
X41t DSDT shows that HKEY.MHKG can be used to verify if the ThinkPad is
tablet-capable (MHKG present), and in tablet mode (bit 3 of MHKG return is
set).

Add an attribute to report this information, "hotkey_tablet_mode".  This
attribute has poll()/select() support, and can be used along with EV_SW
SW_TABLET_MODE to hook userspace to tablet events.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Fixes some minor points in the radio switch code and docs.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Fix a few spelling errors, and also document the EV_SW events thinkpad-acpi
can issue.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Issue EV_SW SW_TABLET_MODE events for HKEY events 0x5009 and 0x500A on the
X41t/X60t/X61t.  As usual, we suppress the HKEY events on the netlink
interface to avoid sending duplicate events to userspace.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Fix a stray ibm-acpi that should have been replaced with thinkpad-acpi.
Thanks to Damjan <gdamjan@mail.net.mk> for noticing this one.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Add some initial documentation detailing what acer-wmi is, and how to use
it. Update the Kconfig entry with a reference to the documentation.
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Also update references to sonypi.txt in Kconfig.
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
CC: Mattia Dongili <malattia@linux.it>
Signed-off-by: NLen Brown <len.brown@intel.com>

Also update references to sony-laptop.txt in Kconfig.
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
CC: Mattia Dongili <malattia@linux.it>
Signed-off-by: NLen Brown <len.brown@intel.com>

Also update references to thinkpad-acpi.txt in Kconfig.
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
CC: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

There are currently various laptop drivers floating about with no central
place for their documentation, which is currently scattered around the top
level Documentation/ directory.

So, as a first step, lets create a Documentation sub-directory, and update
the relevant index files. The work of then moving the existing laptop
driver related documentation will then be handled later.
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
CC: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
CC: Mattia Dongili <malattia@linux.it>
Signed-off-by: NLen Brown <len.brown@intel.com>