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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.
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