Re: The way for disabling input device?

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Tue, Mar 15, 2011 at 06:06:26PM +0900, Joonyoung Shim wrote:
> Hi, all.
> 
> The many smartphones and embedded devices have LCD panel with
> touchscreen. The LCD panel is turned off for power saving and
> touchscreen also is disabled if there isn't user input for a while or if
> user presses power key briefly. This state is such idle, not suspend.
> 
> The framebuffer device driver of kernel supplies sysfs interface to
> control blanking level of framebuffer and  we can turn off LCD panel
> using this sysfs at the above case.
> 
> Currently i know there isn't the generic way for disabling input device
> via user interface, so i am looking for the way for disabling
> input device on kernel side for above case.
> 
> The above case has a condition which the touchscreen is disabled if LCD
> panel is turned off. The framebuffer framework of kernel has notifier
> block to callback on events like hardware display blank change occured,
> so the callback function disabling and enabling input device can be
> called using notifier block of framebuffer. The callback function is
> implemented in each touchscreen driver or can be implemented though
> input core if this can be generic way for input device.
> 
> Actually i wonder whether this approach makes sense. I know this is a
> specific case but certainly necessary function in the smartphone and
> embedded devices.

I do not believe that we should tie the 2 together. I can come up with
scenarios where you woudl want to put the keeboard/touchcsreen to sleep
before turning off the display and vice versa.

Thanks.

-- 
Dmitry