Commit ab5bd206 authored by Mattia Dongili's avatar Mattia Dongili Committed by Len Brown

sony-laptop: Update docs

Update documentation to be consistent with current implementation
(backlight subsys and platform_device).
Signed-off-by: default avatarMattia Dongili <malattia@linux.it>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent a02d1c1d
ACPI Sony Notebook Control Driver (SNC) Readme
----------------------------------------------
Sony Notebook Control Driver (SNC) Readme
-----------------------------------------
Copyright (C) 2004- 2005 Stelian Pop <stelian@popies.net>
This mini-driver drives the ACPI SNC device present in the
ACPI BIOS of the Sony Vaio laptops.
It gives access to some extra laptop functionalities. In
its current form, this driver is mainly useful for controlling the
screen brightness, but it may do more in the future.
You should probably start by trying the sonypi driver, and try
sony_acpi only if sonypi doesn't work for you.
Usage:
------
Loading the sony_acpi module will create a /proc/acpi/sony/
directory populated with a couple of files.
Copyright (C) 2007 Mattia Dongili <malattia@linux.it>
This mini-driver drives the SNC device present in the ACPI BIOS of
the Sony Vaio laptops.
It gives access to some extra laptop functionalities. In its current
form, this driver let the user set or query the screen brightness
through the backlight subsystem and remove/apply power to some devices.
Backlight control:
------------------
If your laptop model supports it, you will find sysfs files in the
/sys/class/backlight/sony/
directory. You will be able to query and set the current screen
brightness:
brightness get/set screen brightness (an iteger
between 0 and 7)
actual_brightness reading from this file will query the HW
to get real brightness value
max_brightness the maximum brightness value
Platform specific:
------------------
Loading the sony-laptop module will create a
/sys/devices/platform/sony-laptop/
directory populated with some files.
You then read/write integer values from/to those files by using
standard UNIX tools.
The files are:
brightness current screen brightness
brightness_default screen brightness which will be set
when the laptop will be rebooted
cdpower power on/off the internal CD drive
audiopower power on/off the internal sound card
lanpower power on/off the internal ethernet card
(only in debug mode)
Note that some files may be missing if they are not supported
by your particular laptop model.
Example usage:
# echo "1" > /proc/acpi/sony/brightness
sets the lowest screen brightness,
# echo "8" > /proc/acpi/sony/brightness
sets the highest screen brightness,
# cat /proc/acpi/sony/brightness
retrieves the current screen brightness.
# echo "1" > /sys/devices/platform/sony-laptop/brightness_default
sets the lowest screen brightness for the next and later reboots,
# echo "8" > /sys/devices/platform/sony-laptop/brightness_default
sets the highest screen brightness for the next and later reboots,
# cat /sys/devices/platform/sony-laptop/brightness_default
retrieves the value.
# echo "0" > /sys/devices/platform/sony-laptop/audiopower
powers off the sound card,
# echo "1" > /sys/devices/platform/sony-laptop/audiopower
powers on the sound card.
Development:
------------
......@@ -49,17 +67,18 @@ pass the option 'debug=1'.
REPEAT: DON'T DO THIS IF YOU DON'T LIKE RISKY BUSINESS.
In your kernel logs you will find the list of all ACPI methods
the SNC device has on your laptop. You can see the GBRT/SBRT methods
used to get/set the brightness, but there are others.
the SNC device has on your laptop. You can see the GCDP/GCDP methods
used to pwer on/off the CD drive, but there are others.
I HAVE NO IDEA WHAT THOSE METHODS DO.
The sony_acpi driver creates, for some of those methods (the most
The sony-laptop driver creates, for some of those methods (the most
current ones found on several Vaio models), an entry under
/proc/acpi/sony/, just like the 'brightness' one. You can create
other entries corresponding to your own laptop methods by further
editing the source (see the 'sony_acpi_values' table, and add a new
structure to this table with your get/set method names).
/sys/devices/platform/sony-laptop, just like the 'cdpower' one.
You can create other entries corresponding to your own laptop methods by
further editing the source (see the 'sony_acpi_values' table, and add a new
entry to this table with your get/set method names using the
HANDLE_NAMES macro).
Your mission, should you accept it, is to try finding out what
those entries are for, by reading/writing random values from/to those
......@@ -77,11 +96,11 @@ Bugs/Limitations:
happened to me, this driver could do very bad things to your
laptop, including permanent damage.
* The sony_acpi and sonypi drivers do not interact at all. In the
future, sonypi could use sony_acpi to do (part of) its business.
* The sony-laptop and sonypi drivers do not interact at all. In the
future, sonypi could use sony-laptop to do (part of) its business.
* spicctrl, which is the userspace tool used to communicate with the
sonypi driver (through /dev/sonypi) does not try to use the
sony_acpi driver. In the future, spicctrl could try sonypi first,
and if it isn't present, try sony_acpi instead.
sony-laptop driver. In the future, spicctrl could try sonypi first,
and if it isn't present, try sony-laptop instead.
......@@ -93,14 +93,14 @@ config SONY_LAPTOP
depends on X86 && ACPI
select BACKLIGHT_CLASS_DEVICE
---help---
This mini-driver drives the ACPI SNC device present in the
ACPI BIOS of the Sony Vaio laptops.
This mini-driver drives the SNC device present in the ACPI BIOS of
the Sony Vaio laptops.
It gives access to some extra laptop functionalities. In
its current form, the only thing this driver does is letting
the user set or query the screen brightness and remove/apply
power to some devices.
It gives access to some extra laptop functionalities. In its current
form, this driver let the user set or query the screen brightness
through the backlight subsystem and remove/apply power to some
devices.
Read <file:Documentation/acpi/sony_acpi.txt> for more information.
Read <file:Documentation/sony-laptop.txt> for more information.
endmenu
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