Switch to indicate ebook mode

[Jordan Crouse]

On 17/12/06 20:50 +0000, Chris Ball wrote:
> >> On Sun, 17 Dec 2006 13:05:52, Dan Williams <dcbw at redhat.com> said:
> 
>    > I can't remember if I ever got a straight answer on this.  Is there
>    > a switch somewhere that we can access that indicates whether or not
>    > the laptop has been swiveled into ebook mode?
> 
> This is <http://dev.laptop.org/ticket/467>.
> 
>    > Ideally, the switch would generate an interrupt which we could
>    > receive and automatically rotate the X display and switch to B&W
>    > mode when the keyboard is hidden [1].  It's not a great experience
>    > to have to expose a toggle somewhere if we can't figure out when
>    > we're in ebook mode, especially if we had to rely on activities to
>    > provide that toggle in their own UI.
> 
> Yeah, it looks like we have the bit, but we don't want to poll it and
> Quanta are blocking on us working out an interface for interrupts, as in
> <http://dev.laptop.org/ticket/224>.  Could we get someone to own that?

This reminds me - I've been meaning to ask how the switches actually work.
There are two of them - one with the output marked PWR_BUT_in and the other
with the output marked EB_MODE.  I understand from the product datasheets
that these are Hall Effect sensors, which in effect detect the presence 
of a magnetic field nearby.  Sensor one (PWR_BUT_in) is located on the
LCD side of the board at the top right near the notch.  Sensor two 
(EB_MODE) is located on the processor side in the same location.  From
the position of sensor 1, I am assuming that it detects a lid opening, and
the magnetic field is located in the base.  I can't at all figure out where
the magnet is for sensor 2, nor how it detects EB mode.

So - long story short, where the heck are the magnets? :)

Jordan

-- 
Jordan Crouse
Senior Linux Engineer
Advanced Micro Devices, Inc.
<www.amd.com/embeddedprocessors>