Date: Fri, 26 Jan 2001 18:02:50 -0800 (PST) From: Richard Hodges <rh@matriplex.com> To: freebsd-hackers@FreeBSD.ORG Subject: NEWBUS: multiple calls needed? Message-ID: <Pine.BSF.4.10.10101261750060.31475-100000@mail.matriplex.com>
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Hi, all!
I am writing a device driver for a device that has three separate
memory areas (plus a 256-byte IO block). At first glance, it
would seem that the correct thing would be something like:
for(x = 0; x < 3; x++) {
device->mem[x] = bus_alloc_resource(dev, SYS_RES_MEMORY,
&device->rid_mem[x], 0, ~0, 1, RF_ACTIVE);
if(device->mem[x] == NULL)
FAIL;
device->bustag[x] = rman_get_bustag(device->mem[x]);
device->bushandle[x] = rman_get_bushandle(device->mem[x]);
device->virt_addr[x] = rman_get_virtual(device->mem[x]);
}
The memory areas "appear" to be fixed relative to each other:
mem1 == base + 0x000000 (size==0x200000)
mem2 == base + 0x201000 (size==0x000100)
mem3 == base + 0x203000 (size==0x000400)
So of course, it is tempting to wonder whether it is really neccessary
to allocate three newbus entities for them. On the other hand, I have
to believe that the BIOS has already set the base and sizes of these
areas, and it would be a really bad idea to pretend that they are a
single (say 3-meg) resource.
I think I will just go ahead with allocating three separate resources
for them, but I would be very interested in other opinions.
Thanks,
-Richard
-------------------------------------------
Richard Hodges | Matriplex, inc.
<title> | 769 Basque Way
rh@matriplex.com | Carson City, NV 89706
775-886-6477 | www.matriplex.com
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