lkml.org 
[lkml]   [2012]   [Feb]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v5 4/5] Extcon: support mutually exclusive relation between cables.
From
On Wed, Feb 22, 2012 at 7:00 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Wednesday 22 February 2012, MyungJoo Ham wrote:
>>
>> On Mon, Feb 20, 2012 at 11:27 AM, Mark Brown
>> <broonie@opensource.wolfsonmicro.com> wrote:
>> > On Fri, Feb 10, 2012 at 03:40:37PM +0900, MyungJoo Ham wrote:
>> >
>> >> +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
>> >> +             #
>> >
>> > sysfs really isn't supposed to have more than one value per file so this
>> > should be something like a directory with one array element per file.
>> > It'd kind of be cheating but the values could be used as the filenames,
>> > though serial numbers would be more idiomatic.
>>
>> Hmm.. I'll either use multiple files with a sub-directory or bin-attr
>> to inhabit the values. Or I'll search for any other convinient way to
>> express such an array thru sysfs.
>
> How about having one file for each cable and list the ones that it
> cannot coexist with. In the above example, that would become
>
> mutually_exclusive/0: "0x6"
> mutually_exclusive/1: "0x1"
> mutually_exclusive/2: "0x9"
> mutually_exclusive/3: "0x4"
>
> The information here is a bit redundant, but this would be much easier
> to understand for human readers. I also wouldn't mind having a list
> of exclusive cable names in each file, while would make it slightly
> harder to parse but very easy for humans:
>
> mutually_exclusive/Video-in: "VGA"
> mutually_exclusive/Video-out: "VGA"
> mutually_exclusive/VGA: "Video-out Video-in"
>
>        Arnd

Ok, here goes an example how it would look like in the next revision of Extcon.
I think this addresses your comments on multistate-support patch (3/5)

/sys/class/extcon/max8997-muic.0/
name: "max8997-muic.0"
state: 0x00000009 /* RW. 0xblahblah format
for both read and write */
mutually_exclusive/
rule.0: 0x3
rule.1: 0x5
rule.2: 0xC
cable.0/
name: "VGA"
state: 1 /* RW: 0 or 1 */
mutually_exclusive/
cable.1
cable.2
cable.1/
...


How about this?




Cheers!
MyungJoo.

--
MyungJoo Ham, Ph.D.
System S/W Lab, S/W Center, Samsung Electronics
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2012-02-24 05:59    [W:0.063 / U:16.988 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site