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+What: /sys/class/extcon/.../
+Date: February 2012
+Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
+Description:
+ Provide a place in sysfs for the extcon objects.
+ This allows accessing extcon specific variables.
+ The name of extcon object denoted as ... is the name given
+ with extcon_dev_register.
+
+ One extcon device denotes a single external connector
+ port. An external connector may have multiple cables
+ attached simultaneously. Many of docks, cradles, and
+ accessory cables have such capability. For example,
+ the 30-pin port of Nuri board (/arch/arm/mach-exynos)
+ may have both HDMI and Charger attached, or analog audio,
+ video, and USB cables attached simultaneously.
+
+ If there are cables mutually exclusive with each other,
+ such binary relations may be expressed with extcon_dev's
+ mutually_exclusive array.
+
+What: /sys/class/extcon/.../name
+Date: February 2012
+Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
+Description:
+ The /sys/class/extcon/.../name shows the name of the extcon
+ object. If the extcon object has an optional callback
+ "show_name" defined, the callback will provide the name with
+ this sysfs node.
+
+What: /sys/class/extcon/.../state
+Date: February 2012
+Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
+Description:
+ The /sys/class/extcon/.../state shows and stores the cable
+ attach/detach information of the corresponding extcon object.
+ If the extcon object has an optional callback "show_state"
+ defined, the showing function is overridden with the optional
+ callback.
+
+ If the default callback for showing function is used, the
+ format is like this:
+ # cat state
+ USB_OTG=1
+ HDMI=0
+ TA=1
+ EAR_JACK=0
+ #
+ In this example, the extcon device has USB_OTG and TA
+ cables attached and HDMI and EAR_JACK cables detached.
+
+ In order to update the state of an extcon device, enter a hex
+ state number starting with 0x:
+ # echo 0xHEX > state
+
+ This updates the whole state of the extcon device.
+ Inputs of all the methods are required to meet the
+ mutually_exclusive conditions if they exist.
+
+ It is recommended to use this "global" state interface if
+ you need to set the value atomically. The later state
+ interface associated with each cable cannot update
+ multiple cable states of an extcon device simultaneously.
+
+What: /sys/class/extcon/.../cable.x/name
+Date: February 2012
+Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
+Description:
+ The /sys/class/extcon/.../cable.x/name shows the name of cable
+ "x" (integer between 0 and 31) of an extcon device.
+
+What: /sys/class/extcon/.../cable.x/state
+Date: February 2012
+Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
+Description:
+ The /sys/class/extcon/.../cable.x/state shows and stores the
+ state of cable "x" (integer between 0 and 31) of an extcon
+ device. The state value is either 0 (detached) or 1
+ (attached).
+
+What: /sys/class/extcon/.../mutually_exclusive/...
+Date: December 2011
+Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
+Description:
+ Shows the relations of mutually exclusiveness. For example,
+ if the mutually_exclusive array of extcon device is
+ {0x3, 0x5, 0xC, 0x0}, then the output is:
+ # ls mutually_exclusive/
+ 0x3
+ 0x5
+ 0xc
+ #
+
+ Note that mutually_exclusive is a sub-directory of the extcon
+ device and the file names under the mutually_exclusive
+ directory show the mutually-exclusive sets, not the contents
+ of the files.