Re: [Adeos-main] Porting to Intel IXP425

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Richard Cochran wrote:
>>Right. And I think the IXP425 has no cascaded IRQ, so you can define
>>__ipipe_mach_irq_mux_p to 0, and do not have to implement
>>__ipipe_mach_demux_irq.
> 
> 
> That was easy.
> 
> (The IXP425 has no cascaded interrupts.)
> 
> Now, about the rest, by reading the other arm ports, I learned the
> following:
> 
> __ipipe_mach_get_dec()
> 
> Returns the periodic timer interval in HW ticks.
> 
> __ipipe_mach_set_dec()
> 
> Sets the periodic timer interval.

The timer is aperiodic (most of the time) when running Xenomai, so
__ipipe_mach_set_dec is called for each timer tick and programs the
timer hardware for the next tick.

> 
> __ipipe_mach_get_tsc()
> 
> Returns the free flowing time stamp register as a 64 bit integer.
> 
> __ipipe_mach_acktimer()
> 
> Called by the timer ISR, clears the timer interrupt.
> 
> __ipipe_mach_release_timer()
> 
> Restores the timer interval to the value expected by Linux.

__ipipe_mach_release_timer is called when Xenomai stops handling the
timer and let Linux handle it.


-- 
                                                 Gilles Chanteperdrix