83xx: requesting external interrupts

Hi list,

I'm trying to port a driver from 2.6.11 to 2.6.21 and I'm stuck on the following line:

	request_irq(MPC83xx_IRQ_EXT5, mpc832xemds_phy_interrupt, SA_SHIRQ, "pm5384", dev);

The first problem is that MPC83xx_IRQ_EXT5 is no longer defined.  If I hard code this to
what I think is the right value (i.e. 21) then request_irq fails on insmod.

I obviously need to do something different now that ARCH=powerpc, but I can't find any
examples of code which requests 83xx external interrupts.  Can anybody help?

TIA,

Alex