Re: MPC8240 EPIC Driver (Attached)

[Andrew Johnson <anj@aps.anl.gov>]

"Mark A. Greer" wrote:
>
> The changes to the openpic code for supporting serial interrupt mode are very minor.

Actually IIRC they're already present in the version shipped with
HHL-2.0.  I don't remember making any changes for that at all on the
MVME2100 support, but my memory has been known to be faulty.

> What I mean is a table where you specify the irq, the offset fo the regs from the base
> address, the sensitivity, and the polarity all separately.  Also the appropriate
> extensions to support serial interrupt mode (e.g., MVME2100 uses that).  With a table
> format something like that, you can avoid the sparse and negative irq's on the
> 8240/107 and still keep things pretty clean looking.

That sounds right.  It could also use the NIRQ field of the Feature
Reporting Register to cross-check that the table given is the correct size
for the chip it's controlling, and have some way of specifying the
presence or absensce of a cascaded i8259 (presumably with its own table).

- Andrew
--
The world is such a cheerful place when viewed from upside-down
It makes a rise of every fall, a smile of every frown

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/