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What: /sys/class/extcon/.../
Date: December 2011
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 simulteneously.
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: December 2011
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: December 2011
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 objecct has an optional callback "show_state"
defined, the showing function is overriden 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 have USB_OTG and TA
cables attached and HDMI and EAR_JACK cables detached.
There are two methods to update state of extcon.
Method 1.
echo CABLE_NAME [0|1] > state
Method 2.
echo 0xHEX > state
Method 1 updates the state (0 or 1) of the
corresponding cable (either the name or index of the cable).
Method 2 updates the whole state of the extcon dev.
Inputs of all the methods are required to meet the
mutually_exclusive contidions if they exist.
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_dev is
{0x3, 0x5, 0xC, 0x0}, the, the output is:
# cat mutually_exclusive
0x3
0x5
0xC
#
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