David Gibson wrote: > On Fri, Jun 21, 2002 at 07:39:03AM -0700, Tom Rini wrote: > >>On Fri, Jun 21, 2002 at 10:52:16AM +1000, David Gibson wrote: >> >>>On Thu, Jun 20, 2002 at 08:50:26AM -0700, Tom Rini wrote: >>> >>>>And I think it can be used, once it gets registered to the ocp_list (and >>>>something later accesses it). >>>> >>> > I can't see why it would need to: ocp_register() will just be calling > pm_register() which will directly provide a usable device identifier > to its callbacks. For that matter I don't see much point in running > the PM stuff through the OCP layer at all rather than just having the > relevant drivers call pm_register() directly. But the last point > might change if useful default power management handlers could be > implemented through the CPM constants added to core_ocp in Armin's > recent patch. > > Incidentally I think a "register" interface could make sense if the > "registration" occured at the point the device was discovered - which > for these embedded devices means unconditionally during board and/or > chip initialization. This is the obvious way to map embedded devices > onto the 2.5 unified device model. Registration at driver > initialization like ocp_register() makes no sense to me.
Thats obvious ^^^^^^^^^^^^^^^^^^ > > Basically there are two quite distinct approaches either of which > would make sense (for any given peripheral/bus type): > a) Register each device as it is discovered. Register each > driver as the appropriate module loads. Whenever either event happens > the common code calls init or probe callbacks in a driver to connect > it to any devices of appropriate type. > b) No registration. When a driver loads, it searches for all > devices of appropriate type, and initializes each of them in turn. I'll need to fix that won't I :) > > Examples of (a) include the new PCI interface, PCMCIA, and the 2.5 > unified device model. Examples of (b) include the old PCI interface > (pci_find_device()) and (some?/all?) non-PCI devices on OF machines > (e.g. Airport). > > Approach (a) is clearly needed to handle hotplug. But that's not an > issue for OCPs (indeed device (not driver) registration will always be > degenerate) so either approach would do. Frankly (a) seems overkill > for OCPs, but it does have the advantage of being easily integrated > into the unified device model. It's not over kill. if I used the entire PCI model, it would be. > > What we have at the moment is mishmash of both models, which *doesn't* > make sense). > This is in devel, I guess what I should have done was fork and do all the work there and then provide a complete solution to devel. :) > armin ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
