[ECOS] 80312 hal support for Intel XScale board

[Richard Wicks <rich at accetnetwork dot com>]

Hello,

I think I've found some bugs with the hal support with the Intel XScale board.

I'm trying to enable a doorbell register so that the host (the PC running 
linux) can interrupt the XScale through the PCI.  I am using the vector 
CYGNUM_HAL_INTERRUPT_DOORBELL which is defined as "21".

In iq80310_misc.c on line 745 within the function "hal_interrupt_mask" is the 
following code:

    case CYGNUM_HAL_INTERRUPT_MESSAGE_0 ...
        CYGNUM_HAL_INTERRUPT_INDEX_REGISTER:
        *IIMR_REG &= ~(1<<(vector - CYGNUM_HAL_INTERRUPT_MESSAGE_0));
	return;

According to the documentation* of the 80312 chip, in section 6.8.5 this 
UNmasks the interrupt rather than masking it.  There is a similar problem 
with hal_interrupt_unmask.  In fact, I think nearly all calls to 
hal_interrupt_mask() actually unmask the interrupt and nearly all calls to 
hal_interrupt_unmask() actually mask the interrupt.

If anybody has gotten doorbell interrupts working on this board, I'd sure 
appreciate it if you can tell me what you did.  As soon as I send an 
interrupt to the board, it locks up.  We can go to polling temporarily but 
would like to avoid it naturally.

Thanks,
-Rich

*Documentation for 80312 can be found here: 
http://developer.intel.com/design/IIO/manuals/273410.htm