diff options
| author | Syed Rafiuddin <srafiuddin@nvidia.com> | 2012-09-03 15:35:12 +0530 |
|---|---|---|
| committer | Varun Colbert <vcolbert@nvidia.com> | 2012-09-11 12:45:31 -0700 |
| commit | 73a1a4ca7ee7fe68449c28e8e3225599badd49a5 (patch) | |
| tree | e53b314050d92bb4ee2547237f75414ff24d648f /Documentation | |
| parent | 3084d4324511c6c68bc155707ebbd5789d4b61df (diff) | |
Extcon: support mutually exclusive relation between cables.
There could be cables that t recannot be attaches simulatenously. Extcon
device drivers may express such information via mutually_exclusive in
struct extcon_dev.
For example, for an extcon device with 16 cables (bits 0 to 15 are
available), if mutually_exclusive = { 0x7, 0xC0, 0x81, 0 }, then, the
following attachments are prohibitted.
{0, 1}
{0, 2}
{1, 2}
{6, 7}
{0, 7}
and every attachment set that are superset of one of the above.
For the detail, please refer to linux/include/linux/extcon.h.
The concept is suggested by NeilBrown <neilb@suse.de>
(cherry picked from commit bde68e60b18208978c50c6fb9bdf29826d2887f3)
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
--
Changes from V5:
- Updated sysfs format
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change-Id: I5849ba647e63e44525c9113a14a6d29fb51f6d64
Signed-off-by: Syed Rafiuddin <srafiuddin@nvidia.com>
Reviewed-on: http://git-master/r/130611
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-extcon | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-extcon b/Documentation/ABI/testing/sysfs-class-extcon index 19b18e986a57..20ab361bd8c6 100644 --- a/Documentation/ABI/testing/sysfs-class-extcon +++ b/Documentation/ABI/testing/sysfs-class-extcon @@ -15,6 +15,10 @@ Description: 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: February 2012 Contact: MyungJoo Ham <myungjoo.ham@samsung.com> @@ -73,3 +77,21 @@ Description: 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_dev is + {0x3, 0x5, 0xC, 0x0}, the, 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. |