At Mon, 9 Sep 2002 10:47:04 +0100,
David Laight wrote:
> 
> On Mon, Sep 09, 2002 at 07:44:52AM +0200, Emmanuel Dreyfus wrote:
> > Here is a better patch for the touchpanel bug. It gives me a much better
> > compromise between stylus move accuracy and interrupt overhead.
> 
> Am I right in thinking that the jornada touchpanel is a resistive
> one connected to a UCB1200 (or maybe UCB1100) and hence to the
> codec/sib serial interface on the SA1100?

IIRC, I could not find much info about the device connected to the
SA1100 serial (SSP), which does the touchpanel and the keyboard.
I think it is some ASIC.

> I would use callouts to generate the touchscreen events while
> the pen is 'down'.  The ISR would just ramp up the voltage
> generator and disable itself.

If the device isn't generating interrupts at a constant rate,
I think disabling interrupt (by writing to a GPIO register) and using
callout is a good idea.

Similar thing could be done for keyboard handling, also.

--
IWAMOTO Toshihiro