On Sat, 18-Jul-2009 at 10:25:06 +0100, Rui Paulo wrote:
> On 18 Jul 2009, at 09:10, Andre Albsmeier wrote:
>
> > On Fri, 17-Jul-2009 at 12:53:53 -0700, Julian Elischer wrote:
> >> Andre Albsmeier wrote:
> >>> [CC'ing this to Rui Paulo since he tried to help me a while ago]
> >>>
> >>> Since my driver is a child of hostb0, I have no idea of how to
> >>> access
> >>> acpi0's memory area. Here is a devinfo -r to make things clear:
> >>>
> >> ...
> >>>
> >>> Earlier, I was given the hint to attach as a child of acpi (see the
> >>> old mail attached below) but in this case I didn't have access to
> >>> the
> >>> hostb registers which I need as well.
> >>>
> >>> The only thing I see is: Attach two drivers -- one as child of acpi
> >>> and another as child of hostb and let them communicate somehow (no
> >>> idea how to do this).
> >>>
> >>> I have also done crazy things like searching for acpi0 and trying
> >>> to bus_alloc_resource() the memory I am interested in but this also
> >>> failed.
> >>>
> >>> Or is it possible to free(!) somehow the address space from acpi0
> >>> and pass it to hostb0 so I can bus_alloc_resource() it?
> >>>
> >>
> >> You can probably make two drivers in one which cooperate to
> >> allow access to both sets of resources.
> >
> > Hmm, that's what I meant by: Attach two drivers -- one as child of
> > acpi
> > and another as child of hostb...
> >
> > And that's similar to Rui Paulo's suggestion a while ago:
> >
> >> You'll probably need to create a fake ACPI child driver to access it.
> >>
> >> Create your identify routine with something like:
> >>
> >> static void mydriver_identify(driver_t *driver, device_t parent)
> >> {
> >> if (device_find_child(parent, "mydriver", -1) == NULL &&
> >> mydriver_match(parent))
> >> device_add_child(parent, "mydriver", -1);
> >> }
> >>
> >> mydriver_match() should check if you were given the acpi0 device.
> >
> > But in order to attach to acpi0, I need to say
> >
> > DRIVER_MODULE( eccmon, acpi, eccmon_driver, eccmon_devclass, NULL,
> > NULL );
> >
> > instead of
> >
> > DRIVER_MODULE( eccmon, hostb, eccmon_driver, eccmon_devclass, NULL,
> > NULL );
> >
> > This way I could attach to acpi but not to hostb anymore....
> >
> > I have searched the net for solutions, I have read newbus-draft.txt
> > and newbus-intro.txt and Warner Losh's newbus-led.c (thanks to all
> > of these my driver is working on other mainboards where it doesn't
> > have to access foreign memory) but didn't find anything.
>
> I'm out of ideas.
> John, do you know if this is a newbus limitation or if it can be
> worked around ?
I assume it is possible somehow, I am just too stupid (it is the first
driver I wrote). John, for easy reference, here is my initial message:
http://lists.freebsd.org/pipermail/freebsd-hackers/2009-July/029127.html
Please remember all, that I need the access to the acpi0 memory location
only for a few reads during probing/attaching, not later.
I have also read somewhere that, when resources are allocated, the
system "walks up" the device tree until it finds the resource. Since
my driver is below hostb0 and hostb0 is below acpi0 I thought it
should work but it doesn't..
Thanks again,
-Andre
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