Add documentation for acer_acpi Signed-off-by: Carlos Corbacho <cathectic@xxxxxxxxx> --- Documentation/acer_acpi.txt | 126 +++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 126 insertions(+), 0 deletions(-) diff --git a/Documentation/acer_acpi.txt b/Documentation/acer_acpi.txt new file mode 100644 index 0000000..bc8cce4 --- /dev/null +++ b/Documentation/acer_acpi.txt @@ -0,0 +1,126 @@ +Acer Laptop ACPI Extras Driver +****************************** + + Copyright (C) 2005-2007 E.M. Smith + Copyright (C) 2007 Carlos Corbacho <cathectic@xxxxxxxxx> + +### THIS IS VERY MUCH A WORK IN PROGRESS. NO WARRANTY GIVEN. IF YOU +### BREAK YOUR LAPTOP USING THIS DRIVER, YOU GET TO KEEP THE PIECES AND +### WE WILL ACCEPT ABSOLUTELY NO RESPONSIBILITY. + +acer_acpi is a driver to allow you to control various aspects of your Acer +laptop hardware using the Linux kernel, on Acer laptops that have an ACPI device +with _HID PNP0C14 - the two supported devices so far are AMW0 and WMID. + +Background +********** + +acer_acpi was originally developed in order to activate the wireless LAN card +under a 64-bit version of Linux, as acerhk[1] (the previous fine solution to the +problem) relied on making 32-bit BIOS calls which are not allowed from a 64-bit +OS. + +However, acer_acpi will work on both x86 and x86-64. + +[1] acerhk: http://www.cakey.de/acerhk/ + +Platform specific +***************** + +Loading acer_acpi will create the following directory: + +/sys/devices/platform/acer_acpi/ + +In this directory are the following files, which you can read/write to with +the standard *NIX tools (cat, echo, etc...). + +wireless Enable/ disable the wireless device +bluetooth Enable/ disable the bluetooth device +threeg Enable/ disable the 3G device (WMID only) + +e.g. + +To enable wireless: + # echo 1 > /sys/devices/platform/acer_acpi/wireless +To disable wireless: + # echo 0 > /sys/devices/platform/acer_acpi/wireless +To read the wireless status: + # cat /sys/devices/platform/acer_acpi/wireless + +Backlight +********* + +If your backlight is supported (WMID only), this directory will exist: + +/sys/class/backlight/acer_acpi/ + +Acer backlights support brightness values of 0 to 15 + +Mail LED +******** + +If your mail LED is supported (AMW0 only), this directory will exist: + +/sys/class/leds/acer_acpi:mail + +Multimedia Keys +*************** + +Some newer Acer laptops inexplicably require an old keyboard quirk to make the +multimedia keys emit scancodes. + +This quirk is automatically applied on those laptops that we know require it. +If the multimedia keys on your laptop do not work, please contact us so we can +add your laptop to this list. + +Bugs/ Limitations +***************** + +* Acer has provided _no_ information or documentation on their hardware - this +driver is the result of the hard work of many people deciphering Acer's +hardware. + +* The behaviour of the wireless LED will depend on your hardware and driver +combination. + +e.g. With the BCM4318 on the 5020 series: + +ndiswrapper: Light blinks on when transmitting +bcm43xx: Solid light, blinks off when transmitting + +* AMW0 does not provide any methods to retrieve the current status of a device. +We therefore store the last value we wrote to the device and return this. On +startup for AMW0, we default to turning all the devices off so we have a sane +default. This means that the status value can be wrong on X86_32 if you use +wistron_btns to manipulate the same hardware. + +* acer_acpi does not yet have any means of deciding whether to enable or disable +entries in sysfs - this means that for hardware that isn't there, you can still +read/ write the corresponding sysfs file. + +(So: Just because there is a bluetooth file, doesn't mean you now actually have +a Bluetooth device.) + +* AMW0 and WMID expose different capabilities (e.g. the mail LED works on AMW0, +but not WMID). + +* We don't gurantee acer_acpi will work on your laptop. We keep a list of known +supported (and some known unsupported hardware) here: +http://code.google.com/p/aceracpi/wiki/SupportedHardware + +If your Acer laptop is not on that list, please send in your DSDT to us. + +Credits +******* + +* Olaf Tauber, who did the real hard work when he developed acerhk +http://www.informatik.hu-berlin.de/~tauber/acerhk + +* All the authors of laptop acpi modules in the kernel, whose work was an +inspiration and a source of good code + +* Mathieu Segaud, who solved the problem with having to modprobe the driver +twice in early versions + +* Jim Ramsay, who reverse engineered, and added support for the new WMID +interface -- 1.4.2.1 - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
