Re: [RFC] Generic implementation for Input enable disable methods

[Onkalo Samu <samu.p.onkalo@nokia.com>]

On Wed, 2010-01-20 at 07:28 +0100, Onkalo Samu.P (Nokia-D/Tampere)
wrote:
> Hi
> 
> Some time ago, there were two parallel implementation proposals for
> disabling input devices. See following email:
> http://www.spinics.net/lists/linux-input/msg05984.html
> 
> It was asked to combine these two to have generic interface.
> I'm proposing following sysfs interface:
> 
> ../input0/disable/avail_xx
> ../input0/disable/disable_xx
> 
> So, new directory for disable control entries. Own entries for each
> of the events or event group. Implementation is using bitmap format:
> 
> Examples
> 
> See what event groups can be disabled. Disable and enable all the groups
> # cat avail_ev
> 0-1,4,20
> # echo "0-1,4,20" > disable_ev
> # cat disable_ev
> 0-1,4,20
> # echo -e "\0" > disable_ev
> # cat disable_ev
>  
> See what individual events can be disabled. Disable and enable one of
> them:
> # cat avail_key
> 528
> # echo "528" > disable_key
> # cat disable_key
> 528
> # echo -e "\0" -> disable_key
> # cat disable_key
> 

After some playing with this interface it is quite clear that this is
not very user friendly. To have better usability, I'll change my
proposal to following one:

Entries are changed to this format:
.../inputx/disable/enable_xx
.../inputx/disable/disable_xx
(no avail_xx anymore)

Use:
echo "1,2" > disable_xx  disable events 1 and 2
echo "" > disable_xx   do nothing
cat disable_xx   list of currently disabled entries

echo "4-5" > enable_xx enable events 4,5,6
echo "" > enable_xx  do nothing
cat enable_xx   list of currenty enabled entries

Read operation returns only events which can be controlled via this
interface.

Enable all currently disabled events:
cat disable_xx > enable_xx

Disable all currently enabled events:
cat enable_xx > disable_XX

This way it is much easier to control individual events.

> Input core just provides sysfs entries and call call-back functions. 
> Actual work is done in the drivers like gpio-keys.
> 
> Does this interface sound acceptable solution?
> If it is, I'll finalize my implentation and send it for review.
> This interface is tested to work with twl4030_keypad driver and
> gpio-keys. It should also work fine with touch screen input drivers.
> 
> This is more or less small embedded device feature. Should it be behind
> configuration flags similar to CONFIG_PM? Of course this would introduce
> some compilation flags to the input-core.
> 
> Regard,
> Samu
> 
> 
> 
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