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: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len 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: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Fixes some minor points in the radio switch code and docs.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Fix a few spelling errors, and also document the EV_SW events thinkpad-acpi
can issue.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len 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: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len 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: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Also update references to thinkpad-acpi.txt in Kconfig.
Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
CC: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
