From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: using cpm interrupts on 8xx From: Nate Pletcher To: linuxppc-embedded@lists.linuxppc.org Content-Type: text/plain Date: 22 May 2002 10:58:47 -0400 Message-Id: <1022079528.1226.15.camel@soundgarden> Mime-Version: 1.0 Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Hello, I'm trying to use IDMA CPM interrupts on custom MPC855t hardware similar to an Embedded Planet CLLF or RPX Lite board. We're using MontaVista's Hard Hat Linux CDK 1.2 with the 2.2.14 kernel and included tools. I'm writing a kernel module to control an onboard FPGA that must DMA data. I've read through the kernel source in arch/ppc/kernel/irq.c and arch/ppc/8xx_io/commproc.c and searched the linuxppc-embedded archives, but I'm still not clear on how to use request_8xxirq() and cpm_install_handler(). Do I need to register a handler for the SIU interrupt for the CPM and then another handler for the individual IDMA interrupt from the CPM? Perhaps someone could point me to some documentation on how to register a CPM interrupt handler. The interrupt hardware on the 8xx is multilevel (CPM interrupts multiplexed into SIU) so it seems that both functions would be necessary. I have read all the MPC8xx documentation on the interrupt hardware so I'm familiar with the structure, but I'm unsure how PPC Linux is setup to handle this. What do I need to do myself and what is provided by the request_/free_irq interface? This is my first Linux device driver so any help on registering interrupt handlers on PPC 8xx would be appreciated. Thanks, Nate ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/