Update the HKEY event driver to:

1. Handle better the second-gen firmware, which has no HKEY mask
   support but does report FN+F3, FN+F4 and FN+F12 without the need
   for NVRAM polling.

   a) always make the mask-related attributes available in sysfs;
   b) use DMI quirks to detect the second-gen firmware;
   c) properly report that FN+F3, FN+F4 and FN+F12 are enabled,
      and available even on mask-less second-gen firmware;

2. Decouple the issuing of hotkey events towards userspace from
   their reception from the firmware.  ALSA mixer and brightness
   event reporting support will need this feature.

3. Clean up the mess in the hotkey driver a great deal.  It is
   still very convoluted, and wants a full refactoring into a
   proper event API interface, but that is not going to happen
   today.

4. Fully reset firmware interface on resume (restore hotkey
   mask and status).

5. Stop losing polled events for no good reason when changing the
   mask and poll frequencies.  We will still lose them when the
   hotkey_source_mask is changed, as well as any that happened
   between driver suspend and driver resume.

The hotkey subdriver now has the notion of user-space-visible hotkey
event mask, as well as of the set of "hotkey" events the driver needs
(because brightness/volume change reports are not just keypress
reports in most ThinkPad models).

With this rewrite, the ABI level is bumped to 0x020500 should
userspace need to know it is dealing with the updated hotkey
subdriver.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>

HKEY event 0x5010 is useless to us: old ThinkPads don't issue it.  Newer
ThinkPads won't issue it anymore.  And all ThinkPads issue 0x1010 and
0x1011 events.

Just silently drop it instead of sending it to userspace.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>

echo "reset" > /proc/acpi/ibm/hotkey should do something non-useless,
so instead of setting it to Fn+F2, Fn+F3, Fn+F5, set it to
hotkey_recommended_mask.

It is not like it will survive for much longer, anyway.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>

Some analysis of the ACPI DSDTs shows that the HKEY pre-enabled mask
is always 0x80c (FN+F3,FN+F4 and FN+F12), which are the hotkeys that
the second gen of HKEY firmware supported (the first gen didn't report
any hotkeys, the second reported these tree hotkeys but had no mask
support, and the third added mask support).

So, this is probably some sort of backwards compatibility with older
versions of the IBM ThinkVantage suite.  We have no use for that, and
I know of exactly ZERO users of that attribute, anyway.  Start the
process of getting rid of it.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
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>

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>