On Mon, Jun 14, 2004 at 11:10:04AM +0100, Adrian Cox wrote: > The attached patch is a start at adding the internal peripherals of the > MPC107/MPC8240/MPC8245 to the OCP bus. I've used thus in the 2.6 port of > my MPC107 I2C driver, which follows shortly. I intend to use this for > the DMA controller later, once I decide what device ID to give it.
Excellent...I was hoping someone would take care of this for MPC10x-ish on-chip devices. > I'm a little uncertain about OCP device IDs. Should there be a separate > I2C device ID for each different I2C programming interface from the same > vendor? Motorola have already given us two separate implementations on > PowerPC. Well, I've been asked this question a few times in similar contexts, but I haven't had a solid answer to give yet. Basically, the question boils down to, "What are the rules for assigning new OCP IDs?". Right now, there are no written rules. However, we have a software "bus" abstraction with a massive amount (32-bit) of IDs available for our use per vendor. My current suggestion is to use this space to assign unique IDs per device even though devices don't show up between architectures (normally). I can actually see cases where two different OCP systems might share a device, but it would be rare if anybody ever implements such a thing at all. Please assign unique IDs per device and per vendor for now. If it gets out of hand in the future, we can revisit the situation. > This is a little bit different from the PPC40x use of OCP, because it's > hard to calculate everything at compile time. This is particularly > caused by the pcore boards, which use the MPC107 but don't use the > interrupt controller. Mark Greer and Kumar Gala each have platforms doing runtime mods, so the Marvell and 85xx ports are good examples to follow. -Matt ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
