ThinkPad ACPI Extras Driver
- Version 0.23
- April 10th, 2009
+ Version 0.24
+ December 11th, 2009
Borislav Deianov <borislav@users.sf.net>
Henrique de Moraes Holschuh <hmh@hmh.eng.br>
For Lenovo ThinkPads with a new
BIOS, it has to be handled either
by the ACPI OSI, or by userspace.
+ The driver does the right thing,
+ never mess with this.
0x1011 0x10 FN+END Brightness down. See brightness
up for details.
Brightness hotkey notes:
-These are the current sane choices for brightness key mapping in
-thinkpad-acpi:
+Don't mess with the brightness hotkeys in a Thinkpad. If you want
+notifications for OSD, use the sysfs backlight class event support.
-For IBM and Lenovo models *without* ACPI backlight control (the ones on
-which thinkpad-acpi will autoload its backlight interface by default,
-and on which ACPI video does not export a backlight interface):
-
-1. Don't enable or map the brightness hotkeys in thinkpad-acpi, as
- these older firmware versions unfortunately won't respect the hotkey
- mask for brightness keys anyway, and always reacts to them. This
- usually work fine, unless X.org drivers are doing something to block
- the BIOS. In that case, use (3) below. This is the default mode of
- operation.
-
-2. Enable the hotkeys, but map them to something else that is NOT
- KEY_BRIGHTNESS_UP/DOWN or any other keycode that would cause
- userspace to try to change the backlight level, and use that as an
- on-screen-display hint.
-
-3. IF AND ONLY IF X.org drivers find a way to block the firmware from
- automatically changing the brightness, enable the hotkeys and map
- them to KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN, and feed that to
- something that calls xbacklight. thinkpad-acpi will not be able to
- change brightness in that case either, so you should disable its
- backlight interface.
-
-For Lenovo models *with* ACPI backlight control:
-
-1. Load up ACPI video and use that. ACPI video will report ACPI
- events for brightness change keys. Do not mess with thinkpad-acpi
- defaults in this case. thinkpad-acpi should not have anything to do
- with backlight events in a scenario where ACPI video is loaded:
- brightness hotkeys must be disabled, and the backlight interface is
- to be kept disabled as well. This is the default mode of operation.
-
-2. Do *NOT* load up ACPI video, enable the hotkeys in thinkpad-acpi,
- and map them to KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN. Process
- these keys on userspace somehow (e.g. by calling xbacklight).
- The driver will do this automatically if it detects that ACPI video
- has been disabled.
+The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events
+automatically for the cases were userspace has to do something to
+implement brightness changes. When you override these events, you will
+either fail to handle properly the ThinkPads that require explicit
+action to change backlight brightness, or the ThinkPads that require
+that no action be taken to work properly.
Bluetooth
its level up and down at every change.
-Volume control -- /proc/acpi/ibm/volume
----------------------------------------
+Volume control (Console Audio control)
+--------------------------------------
+
+procfs: /proc/acpi/ibm/volume
+ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC"
+
+NOTE: by default, the volume control interface operates in read-only
+mode, as it is supposed to be used for on-screen-display purposes.
+The read/write mode can be enabled through the use of the
+"volume_control=1" module parameter.
+
+NOTE: distros are urged to not enable volume_control by default, this
+should be done by the local admin only. The ThinkPad UI is for the
+console audio control to be done through the volume keys only, and for
+the desktop environment to just provide on-screen-display feedback.
+Software volume control should be done only in the main AC97/HDA
+mixer.
+
+
+About the ThinkPad Console Audio control:
+
+ThinkPads have a built-in amplifier and muting circuit that drives the
+console headphone and speakers. This circuit is after the main AC97
+or HDA mixer in the audio path, and under exclusive control of the
+firmware.
+
+ThinkPads have three special hotkeys to interact with the console
+audio control: volume up, volume down and mute.
+
+It is worth noting that the normal way the mute function works (on
+ThinkPads that do not have a "mute LED") is:
-This feature allows volume control on ThinkPad models which don't have
-a hardware volume knob. The available commands are:
+1. Press mute to mute. It will *always* mute, you can press it as
+ many times as you want, and the sound will remain mute.
+
+2. Press either volume key to unmute the ThinkPad (it will _not_
+ change the volume, it will just unmute).
+
+This is a very superior design when compared to the cheap software-only
+mute-toggle solution found on normal consumer laptops: you can be
+absolutely sure the ThinkPad will not make noise if you press the mute
+button, no matter the previous state.
+
+The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain
+amplifiers driving the speakers and headphone output, and the firmware
+also handles volume control for the headphone and speakers on these
+ThinkPads without any help from the operating system (this volume
+control stage exists after the main AC97 or HDA mixer in the audio
+path).
+
+The newer Lenovo models only have firmware mute control, and depend on
+the main HDA mixer to do volume control (which is done by the operating
+system). In this case, the volume keys are filtered out for unmute
+key press (there are some firmware bugs in this area) and delivered as
+normal key presses to the operating system (thinkpad-acpi is not
+involved).
+
+
+The ThinkPad-ACPI volume control:
+
+The preferred way to interact with the Console Audio control is the
+ALSA interface.
+
+The legacy procfs interface allows one to read the current state,
+and if volume control is enabled, accepts the following commands:
echo up >/proc/acpi/ibm/volume
echo down >/proc/acpi/ibm/volume
echo mute >/proc/acpi/ibm/volume
+ echo unmute >/proc/acpi/ibm/volume
echo 'level <level>' >/proc/acpi/ibm/volume
-The <level> number range is 0 to 15 although not all of them may be
-distinct. The unmute the volume after the mute command, use either the
-up or down command (the level command will not unmute the volume).
-The current volume level and mute state is shown in the file.
+The <level> number range is 0 to 14 although not all of them may be
+distinct. To unmute the volume after the mute command, use either the
+up or down command (the level command will not unmute the volume), or
+the unmute command.
+
+You can use the volume_capabilities parameter to tell the driver
+whether your thinkpad has volume control or mute-only control:
+volume_capabilities=1 for mixers with mute and volume control,
+volume_capabilities=2 for mixers with only mute control.
+
+If the driver misdetects the capabilities for your ThinkPad model,
+please report this to ibm-acpi-devel@lists.sourceforge.net, so that we
+can update the driver.
+
+There are two strategies for volume control. To select which one
+should be used, use the volume_mode module parameter: volume_mode=1
+selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing
+(so that volume/mute changes are remembered across shutdown/reboot).
-The ALSA mixer interface to this feature is still missing, but patches
-to add it exist. That problem should be addressed in the not so
-distant future.
+The driver will operate in volume_mode=3 by default. If that does not
+work well on your ThinkPad model, please report this to
+ibm-acpi-devel@lists.sourceforge.net.
+
+The driver supports the standard ALSA module parameters. If the ALSA
+mixer is disabled, the driver will disable all volume functionality.
Fan control and monitoring: fan speed, fan enable/disable
0x0008 HKEY event interface, hotkeys
0x0010 Fan control
0x0020 Backlight brightness
+ 0x0040 Audio mixer/volume control
There is also a kernel build option to enable more debugging
information, which may be necessary to debug driver problems.
and it is always able to disable hot keys. Very old
thinkpads are properly supported. hotkey_bios_mask
is deprecated and marked for removal.
+
+0x020600: Marker for backlight change event support.
+
+0x020700: Support for mute-only mixers.
+ Volume control in read-only mode by default.
+ Marker for ALSA mixer support.
git.openpandora.org / pandora-kernel.git / blobdiff