Date: Sat, 18 Jul 2009 10:10:11 +0200 From: Andre Albsmeier <Andre.Albsmeier@siemens.com> To: Julian Elischer <julian@elischer.org> Cc: freebsd-hackers@freebsd.org, Rui Paulo <rpaulo@freebsd.org>, Andre Albsmeier <Andre.Albsmeier@siemens.com> Subject: Re: Reading acpi memory from a driver attached to hostb Message-ID: <20090718081011.GA6920@curry.mchp.siemens.de> In-Reply-To: <4A60D6D1.3050703@elischer.org> References: <20090717190450.GA4697@curry.mchp.siemens.de> <4A60D6D1.3050703@elischer.org>
next in thread | previous in thread | raw e-mail | index | archive | help
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.
Thanks,
-Andre
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20090718081011.GA6920>