From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3B77F899.5964F88F@aps.anl.gov> Date: Mon, 13 Aug 2001 10:56:09 -0500 From: Andrew Johnson MIME-Version: 1.0 To: Dan Malek Cc: James F Dougherty , linuxppc-embedded@lists.linuxppc.org, cort@cs.nmt.edu, jfd@cs.stanford.edu Subject: Re: MPC8240 EPIC Driver (Attached) References: <200108110718.AAA01730@krakatoa.gigabitnetworks.com> <3B75C40B.8BCDDD2B@mvista.com> Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Dan Malek wrote: > > James F Dougherty wrote: > > > > A while ago, I posted some questions on getting the OpenPIC driver working > > correctly for the EPIC (Embedded Programmable Interrupt Controller) internal > > to the MPC8240. After several attempts on open_pic.*, I gave up, and ported a > > an existing driver. > > Ummm, I'm confused. The existing PowerPC OpenPIC works just fine with > the 8240/8245/MPC107 EPICs, at least on the Sandpoint. Not quite - the Sandpoint has an i8259 as well, and the OpenPic code as shipped with HHL-2.0 assumes that there is one present (at least you have to link in the i8259 code, although you can arrange that it is never called). Not all 8240 systems have an 8259 such as the MVME2100, and I had to #if out some stuff from OpenPic.c to be able to omit the i8259. Then there's the problem of accessing the 8240's interrupts for I2C, 2 DMA channels and Message Unit, which are highly dis-contiguous with the other interrupts; these would appear at IRQs 129, 130, 131 and 134 in the current scheme (needing a rather large and sparse interrupt senses table). Oh, and the 4 Global timer interrupts would have to appear at negative IRQ numbers, so it's a good thing Linux doesn't need to use these. I haven't looked at James' code, but the OpenPIC stuff certainly does need some changes to be truly universal. - 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/