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

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

Documentation/acpi/sony_acpi.txt→Documentation/sony-laptop.txt

+106 −0
Original line number Diff line number Diff line 
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.

drivers/misc/Kconfig

+7 −7
Original line number Diff line number Diff line
@@ -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.



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