Re: power management

[Vojtech P. <vo...@su...>]

On Tue, Jun 19, 2001 at 02:30:02PM -0700, James Simmons wrote:

> 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.

Hmmm, I'll have to take a closer look at how powermanagement is
implement in Linux.

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

Yes, it has been designed for low speed devices, where the overhead
doesn't matter. But there is not a problem with redesigning it.

-- 
Vojtech Pavlik
SuSE Labs