1What:		/sys/class/extcon/.../
2Date:		February 2012
3Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
4Description:
5		Provide a place in sysfs for the extcon objects.
6		This allows accessing extcon specific variables.
7		The name of extcon object denoted as ... is the name given
8		with extcon_dev_register.
9
10		One extcon device denotes a single external connector
11		port. An external connector may have multiple cables
12		attached simultaneously. Many of docks, cradles, and
13		accessory cables have such capability. For example,
14		the 30-pin port of Nuri board (/arch/arm/mach-exynos)
15		may have both HDMI and Charger attached, or analog audio,
16		video, and USB cables attached simultaneously.
17
18		If there are cables mutually exclusive with each other,
19		such binary relations may be expressed with extcon_dev's
20		mutually_exclusive array.
21
22What:		/sys/class/extcon/.../name
23Date:		February 2012
24Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
25Description:
26		The /sys/class/extcon/.../name shows the name of the extcon
27		object. If the extcon object has an optional callback
28		"show_name" defined, the callback will provide the name with
29		this sysfs node.
30
31What:		/sys/class/extcon/.../state
32Date:		February 2012
33Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
34Description:
35		The /sys/class/extcon/.../state shows and stores the cable
36		attach/detach information of the corresponding extcon object.
37		If the extcon object has an optional callback "show_state"
38		defined, the showing function is overridden with the optional
39		callback.
40
41		If the default callback for showing function is used, the
42		format is like this::
43
44		    # cat state
45		    USB_OTG=1
46		    HDMI=0
47		    TA=1
48		    EAR_JACK=0
49		    #
50
51		In this example, the extcon device has USB_OTG and TA
52		cables attached and HDMI and EAR_JACK cables detached.
53
54		In order to update the state of an extcon device, enter a hex
55		state number starting with 0x::
56
57		    # echo 0xHEX > state
58
59		This updates the whole state of the extcon device.
60		Inputs of all the methods are required to meet the
61		mutually_exclusive conditions if they exist.
62
63		It is recommended to use this "global" state interface if
64		you need to set the value atomically. The later state
65		interface associated with each cable cannot update
66		multiple cable states of an extcon device simultaneously.
67
68What:		/sys/class/extcon/.../cable.X/name
69Date:		February 2012
70Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
71Description:
72		The /sys/class/extcon/.../cable.X/name shows the name of cable
73		"X" (integer between 0 and 31) of an extcon device.
74
75What:		/sys/class/extcon/.../cable.X/state
76Date:		February 2012
77Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
78Description:
79		The /sys/class/extcon/.../cable.X/state shows and stores the
80		state of cable "X" (integer between 0 and 31) of an extcon
81		device. The state value is either 0 (detached) or 1
82		(attached).
83
84What:		/sys/class/extcon/.../mutually_exclusive/...
85Date:		December 2011
86Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
87Description:
88		Shows the relations of mutually exclusiveness. For example,
89		if the mutually_exclusive array of extcon device is
90		{0x3, 0x5, 0xC, 0x0}, then the output is::
91
92		    # ls mutually_exclusive/
93		    0x3
94		    0x5
95		    0xc
96		    #
97
98		Note that mutually_exclusive is a sub-directory of the extcon
99		device and the file names under the mutually_exclusive
100		directory show the mutually-exclusive sets, not the contents
101		of the files.
102