diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-extcon | 63 |
1 files changed, 56 insertions, 7 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-extcon b/Documentation/ABI/testing/sysfs-class-extcon index 59a4b1c708d5..19b18e986a57 100644 --- a/Documentation/ABI/testing/sysfs-class-extcon +++ b/Documentation/ABI/testing/sysfs-class-extcon @@ -1,5 +1,5 @@ What: /sys/class/extcon/.../ -Date: December 2011 +Date: February 2012 Contact: MyungJoo Ham <myungjoo.ham@samsung.com> Description: Provide a place in sysfs for the extcon objects. @@ -7,8 +7,16 @@ Description: 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. + What: /sys/class/extcon/.../name -Date: December 2011 +Date: February 2012 Contact: MyungJoo Ham <myungjoo.ham@samsung.com> Description: The /sys/class/extcon/.../name shows the name of the extcon @@ -17,10 +25,51 @@ Description: this sysfs node. What: /sys/class/extcon/.../state -Date: December 2011 +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 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. + + 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 dev. + Inputs of all the methods are required to meet the + mutually_exclusive contidions if they exist. + + It is recommended to use this "global" state interface if + you need to enter 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/.../state shows the cable attach/detach - information of the corresponding extcon object. If the extcon - objecct has an optional callback "show_state" defined, the - callback will provide the name with this sysfs node. + The /sys/class/extcon/.../cable.x/name 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). |