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authorLinus Torvalds <torvalds@woody.linux-foundation.org>2007-11-26 22:09:58 -0500
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-11-26 22:09:58 -0500
commit6b41016032accca5a0ca8bbd35ec5fd7f7bc3aeb (patch)
treeb2f707ebd2c17a3cea3e4ebb425626ec42511634 /Documentation
parent9ccc236269c1a838b58148c94ac0eeeca885b836 (diff)
parenta3f095ade0f5fd2a09a7f523632d762314452871 (diff)
Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (39 commits) ACPI: EC: Workaround for optimized controllers (version 3) ACPI: EC: use printk_ratelimit(), add some DEBUG mode messages Revert "ACPI: EC: Workaround for optimized controllers" ACPI: fix two IRQ8 issues in IOAPIC mode ACPI: Add missing spaces to printk format cpuidle: fix HP nx6125 regression cpuidle: add sched_clock_idle_[sleep|wakeup]_event() hooks cpuidle: fix C3 for no bus-master control case ACPI: thinkpad-acpi: fix oops when a module parameter has no value Revert "Fix very high interrupt rate for IRQ8 (rtc) unless pnpacpi=off" ACPI: EC: Don't init EC early if it has no _INI Revert "acpi: make ACPI_PROCFS default to y" Revert "ACPI: add documentation for deprecated /proc/acpi/battery in ACPI_PROCFS" ACPI: Split out control for /proc/acpi entries from battery, ac, and sbs. ACPI: Video: Increase buffer size for writes to brightness proc file. ACPI: EC: Workaround for optimized controllers ACPI: SBS: Fix retval warning ACPI: Enable MSR (FixedHW) support for T-States ACPI: Get throttling info from BIOS only after evaluating _PDC ACPI: Use _TSS for throttling control, when present. Add error checks. ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/thinkpad-acpi.txt73
1 files changed, 45 insertions, 28 deletions
diff --git a/Documentation/thinkpad-acpi.txt b/Documentation/thinkpad-acpi.txt
index ec499265deca..10c041ca13c7 100644
--- a/Documentation/thinkpad-acpi.txt
+++ b/Documentation/thinkpad-acpi.txt
@@ -1,7 +1,7 @@
1 ThinkPad ACPI Extras Driver 1 ThinkPad ACPI Extras Driver
2 2
3 Version 0.16 3 Version 0.17
4 August 2nd, 2007 4 October 04th, 2007
5 5
6 Borislav Deianov <borislav@users.sf.net> 6 Borislav Deianov <borislav@users.sf.net>
7 Henrique de Moraes Holschuh <hmh@hmh.eng.br> 7 Henrique de Moraes Holschuh <hmh@hmh.eng.br>
@@ -923,19 +923,34 @@ sysfs backlight device "thinkpad_screen"
923This feature allows software control of the LCD brightness on ThinkPad 923This feature allows software control of the LCD brightness on ThinkPad
924models which don't have a hardware brightness slider. 924models which don't have a hardware brightness slider.
925 925
926It has some limitations: the LCD backlight cannot be actually turned on or off 926It has some limitations: the LCD backlight cannot be actually turned on or
927by this interface, and in many ThinkPad models, the "dim while on battery" 927off by this interface, and in many ThinkPad models, the "dim while on
928functionality will be enabled by the BIOS when this interface is used, and 928battery" functionality will be enabled by the BIOS when this interface is
929cannot be controlled. 929used, and cannot be controlled.
930 930
931The backlight control has eight levels, ranging from 0 to 7. Some of the 931On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
932levels may not be distinct. 932has eight brightness levels, ranging from 0 to 7. Some of the levels
933 933may not be distinct. Later Lenovo models that implement the ACPI
934There are two interfaces to the firmware for brightness control, EC and CMOS. 934display backlight brightness control methods have 16 levels, ranging
935To select which one should be used, use the brightness_mode module parameter: 935from 0 to 15.
936brightness_mode=1 selects EC mode, brightness_mode=2 selects CMOS mode, 936
937brightness_mode=3 selects both EC and CMOS. The driver tries to autodetect 937There are two interfaces to the firmware for direct brightness control,
938which interface to use. 938EC and CMOS. To select which one should be used, use the
939brightness_mode module parameter: brightness_mode=1 selects EC mode,
940brightness_mode=2 selects CMOS mode, brightness_mode=3 selects both EC
941and CMOS. The driver tries to autodetect which interface to use.
942
943When display backlight brightness controls are available through the
944standard ACPI interface, it is best to use it instead of this direct
945ThinkPad-specific interface. The driver will disable its native
946backlight brightness control interface if it detects that the standard
947ACPI interface is available in the ThinkPad.
948
949The brightness_enable module parameter can be used to control whether
950the LCD brightness control feature will be enabled when available.
951brightness_enable=0 forces it to be disabled. brightness_enable=1
952forces it to be enabled when available, even if the standard ACPI
953interface is also available.
939 954
940Procfs notes: 955Procfs notes:
941 956
@@ -947,11 +962,11 @@ Procfs notes:
947 962
948Sysfs notes: 963Sysfs notes:
949 964
950The interface is implemented through the backlight sysfs class, which is poorly 965The interface is implemented through the backlight sysfs class, which is
951documented at this time. 966poorly documented at this time.
952 967
953Locate the thinkpad_screen device under /sys/class/backlight, and inside it 968Locate the thinkpad_screen device under /sys/class/backlight, and inside
954there will be the following attributes: 969it there will be the following attributes:
955 970
956 max_brightness: 971 max_brightness:
957 Reads the maximum brightness the hardware can be set to. 972 Reads the maximum brightness the hardware can be set to.
@@ -961,17 +976,19 @@ there will be the following attributes:
961 Reads what brightness the screen is set to at this instant. 976 Reads what brightness the screen is set to at this instant.
962 977
963 brightness: 978 brightness:
964 Writes request the driver to change brightness to the given 979 Writes request the driver to change brightness to the
965 value. Reads will tell you what brightness the driver is trying 980 given value. Reads will tell you what brightness the
966 to set the display to when "power" is set to zero and the display 981 driver is trying to set the display to when "power" is set
967 has not been dimmed by a kernel power management event. 982 to zero and the display has not been dimmed by a kernel
983 power management event.
968 984
969 power: 985 power:
970 power management mode, where 0 is "display on", and 1 to 3 will 986 power management mode, where 0 is "display on", and 1 to 3
971 dim the display backlight to brightness level 0 because 987 will dim the display backlight to brightness level 0
972 thinkpad-acpi cannot really turn the backlight off. Kernel 988 because thinkpad-acpi cannot really turn the backlight
973 power management events can temporarily increase the current 989 off. Kernel power management events can temporarily
974 power management level, i.e. they can dim the display. 990 increase the current power management level, i.e. they can
991 dim the display.
975 992
976 993
977Volume control -- /proc/acpi/ibm/volume 994Volume control -- /proc/acpi/ibm/volume