Fabio Giovagnini wrote:
> Hi Dale, 

Hi Fabio,

Sorry for the delay in responding. I was at the ESC conference this week.

> maybe I need to be more clear about my condition.
> 1) I connected the ads7843 to general I/O ports because the SPIs available on 
> sh2a7203 have been be used for other functions;
> 2) My real problem is the following: I wrote an ADS7843 device driver as a 
> button driver of the input subsystem. I configured the ads7843 with INT 

You wrote the driver? I just used the existing one in the 2.6.28.2 kernel.

> enabled; so when the touch is pressed I have a burst of IRQ. The IRQ handler 
> read the ads7843 and return to the input subsystem the abs values of the 
> touchscreen.

I seem to recall you need disable the interrupt upon #PENIRQ and allow the
polling code to do the job of determining the pen up event.

> The user program open the file /dev/input/event0 and with the select waits for 
> data; what I see is: during all the time I have a finger on the touch only IRQ 
> handler is exeuted and no action is done in the user program. I tried also 
> opening /dev/input/event0 with O_NONBLOCK flag but nothing changes.

The existing driver uses the event system. The easiest way to see what I did
is to unpack a 2.6.28.2 linux tarball and apply the patch I've attached to this post.

Dale Larson
Johnson Controls, Inc