diff options
Diffstat (limited to 'Documentation/thinkpad-acpi.txt')
| -rw-r--r-- | Documentation/thinkpad-acpi.txt | 71 |
1 files changed, 65 insertions, 6 deletions
diff --git a/Documentation/thinkpad-acpi.txt b/Documentation/thinkpad-acpi.txt index 10c041ca13c..70d91a52e0f 100644 --- a/Documentation/thinkpad-acpi.txt +++ b/Documentation/thinkpad-acpi.txt @@ -215,6 +215,11 @@ The following commands can be written to the /proc/acpi/ibm/hotkey file: ... any other 8-hex-digit mask ... echo reset > /proc/acpi/ibm/hotkey -- restore the original mask +The procfs interface does not support NVRAM polling control. So as to +maintain maximum bug-to-bug compatibility, it does not report any masks, +nor does it allow one to manipulate the hot key mask when the firmware +does not support masks at all, even if NVRAM polling is in use. + sysfs notes: hotkey_bios_enabled: @@ -231,17 +236,26 @@ sysfs notes: to this value. hotkey_enable: - Enables/disables the hot keys feature, and reports - current status of the hot keys feature. + Enables/disables the hot keys feature in the ACPI + firmware, and reports current status of the hot keys + feature. Has no effect on the NVRAM hot key polling + functionality. 0: disables the hot keys feature / feature disabled 1: enables the hot keys feature / feature enabled hotkey_mask: - bit mask to enable driver-handling and ACPI event - generation for each hot key (see above). Returns the - current status of the hot keys mask, and allows one to - modify it. + bit mask to enable driver-handling (and depending on + the firmware, ACPI event generation) for each hot key + (see above). Returns the current status of the hot keys + mask, and allows one to modify it. + + Note: when NVRAM polling is active, the firmware mask + will be different from the value returned by + hotkey_mask. The driver will retain enabled bits for + hotkeys that are under NVRAM polling even if the + firmware refuses them, and will not set these bits on + the firmware hot key mask. hotkey_all_mask: bit mask that should enable event reporting for all @@ -257,6 +271,40 @@ sysfs notes: handled by the firmware anyway. Echo it to hotkey_mask above, to use. + hotkey_source_mask: + bit mask that selects which hot keys will the driver + poll the NVRAM for. This is auto-detected by the driver + based on the capabilities reported by the ACPI firmware, + but it can be overridden at runtime. + + Hot keys whose bits are set in both hotkey_source_mask + and also on hotkey_mask are polled for in NVRAM. Only a + few hot keys are available through CMOS NVRAM polling. + + Warning: when in NVRAM mode, the volume up/down/mute + keys are synthesized according to changes in the mixer, + so you have to use volume up or volume down to unmute, + as per the ThinkPad volume mixer user interface. When + in ACPI event mode, volume up/down/mute are reported as + separate events, but this behaviour may be corrected in + future releases of this driver, in which case the + ThinkPad volume mixer user interface semanthics will be + enforced. + + hotkey_poll_freq: + frequency in Hz for hot key polling. It must be between + 0 and 25 Hz. Polling is only carried out when strictly + needed. + + Setting hotkey_poll_freq to zero disables polling, and + will cause hot key presses that require NVRAM polling + to never be reported. + + Setting hotkey_poll_freq too low will cause repeated + pressings of the same hot key to be misreported as a + single key press, or to not even be detected at all. + The recommended polling frequency is 10Hz. + hotkey_radio_sw: if the ThinkPad has a hardware radio switch, this attribute will read 0 if the switch is in the "radios @@ -1263,3 +1311,14 @@ Sysfs interface changelog: and the hwmon class for libsensors4 (lm-sensors 3) compatibility. Moved all hwmon attributes to this new platform device. + +0x020100: Marker for thinkpad-acpi with hot key NVRAM polling + support. If you must, use it to know you should not + start an userspace NVRAM poller (allows to detect when + NVRAM is compiled out by the user because it is + unneeded/undesired in the first place). +0x020101: Marker for thinkpad-acpi with hot key NVRAM polling + and proper hotkey_mask semanthics (version 8 of the + NVRAM polling patch). Some development snapshots of + 0.18 had an earlier version that did strange things + to hotkey_mask. |