Older ThinkPad models do not export some of the hot keys over the
event-based ACPI hot key interface.  For these models, one has to poll
the CMOS NVRAM to check the key state at a rate faster than the expected
rate at which the user might repeatedly press the same hot key.

This patch implements this functionality for many of the hotkeys in a
transparent way: hot keys will now Just Work, and the driver knows the
best approach (events or NVRAM polling) to employ, based on the
HKEY.MHKA ACPI method.

Also, the driver can turn off the polling when there are no users for
the hot keys that need such polling.

The NVRAM-based hot keys of the A3x series that have never been
implemented by later models are not supported, to avoid changes in the
keymap of the input devices that could cause headaches in the future.

There is a Kconfig option to avoid compiling the NVRAM polling code, as
it is not very small, and unlikely to be useful on any ThinkPad newer
than a T40, X31 or R52.

This feature is based on a previous effort by Richard Hughes.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Richard Hughes <hughsient@gmail.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Refactor and organize the code a bit for the NVRAM polling support:

1. Split hotkey_get/set into hotkey_status_get/set and hotkey_mask_get/set;
2. Cache the status of hot key mask for later driver use;
3. Make sure the cache of hot key mask is refreshed when needed;
4. log a printk notice when the firmware doesn't set the hot key
   mask to exactly what we asked it to;
5. Add proper locking to the data structures.

Only (4) should be user-noticeable, but there is a chance (5) fixes
some unknown/unreported race conditions.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Add a "brightness_enable" module parameter that allows the local admin to
force the backlight support to not be enabled.

It can also be used to force the backlight support to be enabled, but that
is currently a no-op as the backlight support is enabled by default when
available.  This will be changed by a different patch.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Lenovo ThinkPads often have 16 brightness levels in EC, and not just eight
levels like older ThinkPads.  They also have standard ACPI backlight
brightness control.

We detect the number of brightness levels by the presence of a BCLL package
with 16 entries.  If BCLL is not there, we assume eight levels (Z6*).  If
it is there, but it doesn't have 16 entries, we assume eight levels (T60).
Otherwise we assume sixteen levels (T61, X61, etc).

We don't use _BCL because it can have side-effects in thinkpads.  Thanks to
Thomas Renninger <trenn@suse.de> for notifying me of this potential
problem.

Using the standard ACPI backlight brightness control *instead* of the
native thinkpad backlight control is a better idea, though.  A different
patch will take care of this.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Thomas Renninger <trenn@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Convert from class_device to device for hwmon_device_register/unregister
Signed-off-by: NTony Jones <tonyj@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NMark M. Hoffman <mhoffman@lightlink.com>

Thinkpad-acpi has some driver attributes (debug level, sysfs interface
version, etc) that also belong to the new hwmon driver.  Duplicate them
there.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Use a separate platform device and driver ("thinkpad_hwmon") to attach
hwmon attributes and class, and add a name attribute of "thinkpad" to
it, which defines the hwmon device name for libsensors4.

This makes thinkpad-acpi compatible with libsensors4 from lm-sensors, and
the platform driver and device split will make it much easier to separate
hwmon functionality into its own module later on.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

Increase tp_features to 32 bits.  It is too close to running out of room.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Revert new 2.6.23 CONFIG_THINKPAD_ACPI_INPUT_ENABLED Kconfig option because
it would create a legacy we don't want to support.

CONFIG_THINKPAD_ACPI_INPUT_ENABLED was added to try to fix an issue that is
now moot with the addition of the netlink ACPI event report interface to
the ACPI core.

Now that ACPI core can send events over netlink, we can use a different
strategy to keep backwards compatibility with older userspace, without the
need for the CONFIG_THINKPAD_ACPI_INPUT_ENABLED games.  And it arrived
before CONFIG_THINKPAD_ACPI_INPUT_ENABLED made it to a stable mainline
kernel, even, which is Good.

This patch is in sync with some changes to thinkpad-acpi backports, that
will keep things sane for userspace across different combinations of kernel
versions, thinkpad-acpi backports (or the lack thereof), and userspace
capabilities:

Unless a module parameter is used, thinkpad-acpi will now behave in such a
way that it will work well (by default) with userspace that still uses only
the old ACPI procfs event interface and doesn't care for thinkpad-acpi
input devices.

It will also always work well with userspace that has been updated to use
both the thinkpad-acpi input devices, and ACPI core netlink event
interface, regardless of any module parameter.

The module parameter was added to allow thinkpad-acpi to work with
userspace that has been partially updated to use thinkpad-acpi input
devices, but not the new ACPI core netlink event interface.  To use this
mode of hot key reporting, one has to specify the hotkey_report_mode=2
module parameter.

The thinkpad-acpi driver exports the value of hotkey_report_mode through
sysfs, as well.  thinkpad-acpi backports to older kernels, that do not
support the new ACPI core netlink interface, have code to allow userspace
to switch hotkey_report_mode at runtime through sysfs.  This capability
will not be provided in mainline thinkpad-acpi as it is not needed there.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Michael S. Tsirkin <mst@dev.mellanox.co.il>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Richard Hughes <hughsient@gmail.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Thomas Renninger reports that if one tries to load thinkpad-acpi in a
non-thinkpad, one gets:

Call Trace:
 [<ffffffff802fa57d>] kref_get+0x2f/0x36
 [<ffffffff802f97f7>] kobject_get+0x12/0x17
 [<ffffffff8036dfd7>] get_driver+0x14/0x1a
 [<ffffffff8036dfee>] driver_remove_file+0x11/0x32
 [<ffffffff8823b9be>] :thinkpad_acpi:thinkpad_acpi_module_exit+0xa8/0xfc
 [<ffffffff8824b8a0>] :thinkpad_acpi:thinkpad_acpi_module_init+0x74a/0x776
 [<ffffffff8024f968>] __link_module+0x0/0x25
 [<ffffffff80252269>] sys_init_module+0x162c/0x178f
 [<ffffffff8020bc2e>] system_call+0x7e/0x83

So, track if the platform driver and its driver attributes were registered,
and only deallocate them in that case.

This patch is based on Thomas Renninger's patch for the issue.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

modpost is going to use these to create e.g. acpi:ACPI0001
in modules.alias.
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

It appears that Lenovo decided to break the EC brightness control interface
in a weird way in their latest BIOSes.  Fortunately, the old CMOS NVRAM
interface works just fine in such BIOSes.

Add a module parameter that allows the user to select which strategy to use
for brightness control: EC, NVRAM, or both.  By default, do both (which is
the way thinkpad-acpi used to work until now) on IBM ThinkPads, and use
NVRAM only on Lenovo ThinkPads.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Keep note of ThinkPad model, BIOS and EC firmware information, and log it
on startup.  Makes for far more readable code in places, too.

This patch also adds Lenovo's PCI ID to the pci ids table.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Rename an internal driver constant, on request by Len Brown.  Also,
document exactly what it is for.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Some subdrivers could benefit from resume handling, so add the
infrastructure for simple resume handling.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Register an input device to send input events to userspace.

This patch is based on a patch by Richard Hughes <hughsient@gmail.com>.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Richard Hughes <hughsient@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Some ThinkPad models, notably the T60 and X60, have a slider switch to
enable and disable the radios.  The switch has the capability of
force-disabling the radios in hardware on most models, and it is supposed
to affect all radios (WLAN, WWAN, BlueTooth).

Export the switch state as a sysfs attribute, on ThinkPads where it is
available.

Thanks to Henning Schild for asking for this feature, and for tracking down
the EC register that holds the radio switch state.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Henning Schild <henning@wh9.tu-dresden.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Revise ACPI HKEY functionality to better interface with the firmware, and
enable up to 32 regular hotkeys, instead of just 16 of them.  Ouch.

This takes care of most keys one used to have to do CMOS NVRAM polling on,
and should drop the need for tpb, thinkpad-keys, and other such 5Hz NVRAM
polling power vampires on most modern ThinkPads ;-)

And, just to add insult to injury, this was sort of working since forever
through the procfs interface, but nobody noticed or tried an echo
0xffffffff > /proc/acpi/ibm/hotkey and told me it would generate weird
events. ARGH!

Thanks to Richard Hughes for kicking off the work that ended up with this
discovery, and to Matthew Garret for calling my attention to the fact that
newer ThinkPads were indeed generating ACPI GPEs when such hot keys were
pressed.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Richard Hughes <hughsient@gmail.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

The initial version of the thinkpad-acpi sysfs interface (not yet released
in any stable mainline kernel) made liberal use of named sysfs groups, in
order to get the attributes more organized.

This proved to be a really bad design decision.  Maybe if attribute groups
were as flexible as a real directory, and if binary attributes were not
second-class citizens, the idea of subdirs and named groups would not have
been so bad.

This patch makes all the thinkpad-acpi sysfs groups anonymous (thus
removing the subdirs), adds the former group names as a prefix (so that
hotkey/enable becomes hotkey_enable for example), and updates the
documentation.

These changes will make the thinkpad-acpi sysfs ABI a lot easier to
maintain.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

This patch makes the needlessly global fan_mutex static.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Add support to sysfs to the wan and bluetooth subdrivers.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Add the hotkey sysfs support.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Len Brown considers that an active by default fan control interface in
laptops may be too close to giving users enough rope.  There is a good
chance he is quite correct on this, especially if someone decides to use
that interface in applets and users are not aware of its risks.

This patch adds a master switch to thinkpad-acpi that enables or disables
the entire fan-control feature as a module parameter: "fan_control".  It
defaults to disabled.  Set it to non-zero to enable fan control.

Also, the patch removes the expermiental status from fan control, since it
is stable enough to not be called experimental, and the master switch makes
it safe enough to do so.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Update the brightness sysfs interface (done through the backlight class) to
be in line with the rest of the thinkpad-acpi driver.

This renames the incorrect, un-obvious, and clash-prone name of "ibm" for
the backlight device to a much more fitting and descriptive
"thinkpad_screen".  This is something I wanted to do for quite a while...
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Export sysfs attributes to monitor and control the internal thinkpad fan
(some thinkpads have more than one fan, but thinkpad-acpi doesn't support
the second fan yet).  The sysfs interface follows the hwmon design guide
for fan devices.

Also, fix some stray "thermal" files in the fan procfs description that
have been there forever, and officially support "full-speed" as the name
for the PWM-disabled state of the fan controller to keep it in line with
the hwmon interface.  It is much better a name for that mode than the
unobvious "disengaged" anyway.  Change the procfs interface to also accept
full-speed as a fan level, but still report it as disengaged for backwards
compatibility.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Export thinkpad thermal sensors to sysfs, following the hwmon
specification for thermal monitoring sensors.

ThinkPad thermal monitoring is done by the EC.  Sensors can show up or
disappear at runtime when they are inside hotswappable hardware, such as
batteries.  Sensors that are not available return -ENXIO when accessed.

Up to 16 thermal sensors are supported on new firmware (but nobody has
reported a ThinkPad with more than 12 sensors so far), and 8 sensors are
supported on older firmware.  Thermal sensor mapping is model-specific.
Precision varies, it is 1 degree Celcius on new ThinkPads, but higher on
some older models.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Add proper mutex locking to some data structures access subject to races
due to concurrent access of driver functions on the hotkey and fan
subdrivers.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Add infrastructure to deal with sysfs attributes and grouping, and helpers
for common sysfs parsing.  Switch driver attributes to use them.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Add the sysfs attributes for the platform driver.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Register thinkpad-acpi platform driver and platform device for the device
model.  Also register the platform device with the hwmon class.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Clean-up the thermal subdriver for sysfs conversion.  Make thermal_get_*
reentrancy-safe while at it, and add the missing thermal_read_mode variable
to the header file.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Some ThinkPad CMOS commands subdriver cleanups, and also rename/promote
cmos_eval to a ACPI helper function, as it is used by many other
subdrivers.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Cleanup video subdriver for sysfs conversion, and properly check
result status of acpi_evalf.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Prepare bluetooth and wan driver code to be more easily hooked into sysfs
helpers, by separating the procfs logic from the device attribute handling.

These changes also remove the entries from procfs on notebooks without the
bluetooth/wan hardware installed.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Mark acpi_evalf and friends __must_check.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Prepare the thinkpad-acpi driver for the conversion to the device
model, by renaming variables and doing other glue work that shall
make the later patches much cleaner.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Use a bitfield to hold boolean module-wide flags, to conserve some memory.
It is easy and it is clean, so we do it just for the heck of it even if it
saves very little space.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Save some memory by using bitfields to hold boolean flags for the
subdrivers.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Improve the detection of ThinkPads, so as to reduce the chances of false
positives.

Since this could potentially add false negatives on the very old models,
add a module parameter to force the detection of a thinkpad.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

Move the .init method from ibms struct to another struct, and use a list
head to control which subdrivers have been activated.

This allows us to have the subdriver init methods marked __init, saving
quite a lot of .text size, and even a bit of .data size as some data can
now be made __initdata.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>