power management

[James S. <jsi...@tr...>]

So far for power management I have:

Placed a pm_dev inside input_dev.

If the input_dev has a struct pm_dev we do the following.

Every time input_open is called pm_access is called.

When input_close is called and handle->open==0 I call pm_idle_dev

For input_unregister_device I call pm_unregister(dev->pm_dev);

I find pm_register_device too driver specific to make generic. 
The next problem is power management for that particular device via a
key/button. I like to power the device off/on and control the level of
power going to the device. For example the touchscreen I'm working on. It
would be nice to dim/brighten the frontlight. The question is how to
implement this fine grain control.

P.S
   serio->write can send only one char at a time?