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Based on kernel version 3.15.4. Page generated on 2014-07-07 09:03 EST.

1	Sony Notebook Control Driver (SNC) Readme
2	-----------------------------------------
3		Copyright (C) 2004- 2005 Stelian Pop <stelian@popies.net>
4		Copyright (C) 2007 Mattia Dongili <malattia@linux.it>
5	
6	This mini-driver drives the SNC and SPIC device present in the ACPI BIOS of the
7	Sony Vaio laptops. This driver mixes both devices functions under the same
8	(hopefully consistent) interface. This also means that the sonypi driver is
9	obsoleted by sony-laptop now.
10	
11	Fn keys (hotkeys):
12	------------------
13	Some models report hotkeys through the SNC or SPIC devices, such events are
14	reported both through the ACPI subsystem as acpi events and through the INPUT
15	subsystem. See the logs of /proc/bus/input/devices to find out what those
16	events are and which input devices are created by the driver.
17	Additionally, loading the driver with the debug option will report all events
18	in the kernel log.
19	
20	The "scancodes" passed to the input system (that can be remapped with udev)
21	are indexes to the table "sony_laptop_input_keycode_map" in the sony-laptop.c
22	module.  For example the "FN/E" key combination (EJECTCD on some models)
23	generates the scancode 20 (0x14).
24	
25	Backlight control:
26	------------------
27	If your laptop model supports it, you will find sysfs files in the
28	/sys/class/backlight/sony/
29	directory. You will be able to query and set the current screen
30	brightness:
31		brightness		get/set screen brightness (an integer
32					between 0 and 7)
33		actual_brightness	reading from this file will query the HW
34					to get real brightness value
35		max_brightness		the maximum brightness value
36	
37	
38	Platform specific:
39	------------------
40	Loading the sony-laptop module will create a
41	/sys/devices/platform/sony-laptop/
42	directory populated with some files.
43	
44	You then read/write integer values from/to those files by using
45	standard UNIX tools.
46	
47	The files are:
48		brightness_default	screen brightness which will be set
49					when the laptop will be rebooted
50		cdpower			power on/off the internal CD drive
51		audiopower		power on/off the internal sound card
52		lanpower		power on/off the internal ethernet card
53					(only in debug mode)
54		bluetoothpower		power on/off the internal bluetooth device
55		fanspeed		get/set the fan speed
56	
57	Note that some files may be missing if they are not supported
58	by your particular laptop model.
59	
60	Example usage:
61		# echo "1" > /sys/devices/platform/sony-laptop/brightness_default
62	sets the lowest screen brightness for the next and later reboots,
63		# echo "8" > /sys/devices/platform/sony-laptop/brightness_default
64	sets the highest screen brightness for the next and later reboots,
65		# cat /sys/devices/platform/sony-laptop/brightness_default
66	retrieves the value.
67	
68		# echo "0" > /sys/devices/platform/sony-laptop/audiopower
69	powers off the sound card,
70		# echo "1" > /sys/devices/platform/sony-laptop/audiopower
71	powers on the sound card.
72	
73	
74	RFkill control:
75	---------------
76	More recent Vaio models expose a consistent set of ACPI methods to
77	control radio frequency emitting devices. If you are a lucky owner of
78	such a laptop you will find the necessary rfkill devices under
79	/sys/class/rfkill. Check those starting with sony-* in
80		# grep . /sys/class/rfkill/*/{state,name}
81	
82	
83	Development:
84	------------
85	
86	If you want to help with the development of this driver (and
87	you are not afraid of any side effects doing strange things with
88	your ACPI BIOS could have on your laptop), load the driver and
89	pass the option 'debug=1'.
90	
91	REPEAT: DON'T DO THIS IF YOU DON'T LIKE RISKY BUSINESS.
92	
93	In your kernel logs you will find the list of all ACPI methods
94	the SNC device has on your laptop.
95	
96	* For new models you will see a long list of meaningless method names,
97	reading the DSDT table source should reveal that:
98	(1) the SNC device uses an internal capability lookup table
99	(2) SN00 is used to find values in the lookup table
100	(3) SN06 and SN07 are used to call into the real methods based on
101	    offsets you can obtain iterating the table using SN00
102	(4) SN02 used to enable events.
103	Some values in the capability lookup table are more or less known, see
104	the code for all sony_call_snc_handle calls, others are more obscure.
105	
106	* For old models you can see the GCDP/GCDP methods used to pwer on/off
107	the CD drive, but there are others and they are usually different from
108	model to model.
109	
110	I HAVE NO IDEA WHAT THOSE METHODS DO.
111	
112	The sony-laptop driver creates, for some of those methods (the most
113	current ones found on several Vaio models), an entry under
114	/sys/devices/platform/sony-laptop, just like the 'cdpower' one.
115	You can create other entries corresponding to your own laptop methods by
116	further editing the source (see the 'sony_nc_values' table, and add a new
117	entry to this table with your get/set method names using the
118	SNC_HANDLE_NAMES macro).
119	
120	Your mission, should you accept it, is to try finding out what
121	those entries are for, by reading/writing random values from/to those
122	files and find out what is the impact on your laptop.
123	
124	Should you find anything interesting, please report it back to me,
125	I will not disavow all knowledge of your actions :)
126	
127	See also http://www.linux.it/~malattia/wiki/index.php/Sony_drivers for other
128	useful info.
129	
130	Bugs/Limitations:
131	-----------------
132	
133	* This driver is not based on official documentation from Sony
134	  (because there is none), so there is no guarantee this driver
135	  will work at all, or do the right thing. Although this hasn't
136	  happened to me, this driver could do very bad things to your
137	  laptop, including permanent damage.
138	
139	* The sony-laptop and sonypi drivers do not interact at all. In the
140	  future, sonypi will be removed and replaced by sony-laptop.
141	
142	* spicctrl, which is the userspace tool used to communicate with the
143	  sonypi driver (through /dev/sonypi) is deprecated as well since all
144	  its features are now available under the sysfs tree via sony-laptop.
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