Date: Tue, 19 Sep 2000 07:01:33 -0700 (PDT) From: papowell@astart.com To: imp@village.org, papowell@astart.com Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: Device driver, memory map failing, and it is probably obvious Message-ID: <200009191401.HAA16643@h4.private>
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> From owner-freebsd-hackers@FreeBSD.ORG Sun Sep 17 20:03:11 2000
> To: papowell@astart.com
> Subject: Re: Device driver, memory map failing, and it is probably obvious
> Cc: freebsd-hackers@FreeBSD.ORG
> Date: Sun, 17 Sep 2000 21:01:44 -0600
> From: Warner Losh <imp@village.org>
>
> In message <200009180220.TAA12263@h4.private> papowell@astart.com writes:
> : I am making a driver for a VERY old PCI device.
> : > digic->digic_mem_res = bus_alloc_resource(dev, SYS_RES_MEMORY,
> : > &digic->digic_mem_rid,
> : > 0, ~0, 256, RF_ACTIVE|RF_SHAREABLE);
>
> : Could this be the problem?
>
> Where do you initialize digic_mem_rid? You should set this equal to
> the BAR offset in the PCI config space that corresponds to this
> memory.
>
> Warner
>
BINGO! I added the following:
/* now get the memory resources */
digic->digic_mem_rid = DIGI_LOMEM;
digic->digic_mem_res = bus_alloc_resource(dev, SYS_RES_MEMORY,
&digic->digic_mem_rid,
0, ~0, 256, RF_ACTIVE|RF_SHAREABLE);
By the way, from the bus_alloc_resource man page:
/* now get the memory resources */
digic->digic_mem_rid = DIGI_LOMEM;
digic->digic_mem_res = bus_alloc_resource(dev, SYS_RES_MEMORY,
&digic->digic_mem_rid,
0, ~0, 256, RF_ACTIVE|RF_SHAREABLE);
> rid points to a bus specific handle that identifies the resource being
> allocated. For ISA this is an index into an array of resources that have
> been setup for this device by either the PnP mechanism, or via the hints
> mechanism. For PCCARD, similar things are used as of writing, but that
> may change in the future with newcard. For PCI it just happens to be the
> offset into pci config space which has a word that describes the re-
> source. The bus methods are free to change the RIDs that they are given
> as a parameter. You must not depend on the value you gave it earlier.
I might suggest a small rewording:
rid points to a value that contains a bus specific handle
that identifies the resource being
allocated. For ISA this is an index into an array of resources that have
been setup for this device by either the PnP mechanism, or via the hints
mechanism. A value of 0 will use the first resource. See XXXXX for
more details. For PCCARD, similar things are used as of writing, but that
may change in the future with newcard. For PCI it is the
offset into pci config space which has a word that describes the re-
source. The bus methods are may change the values of the RIDs that they are given
as a parameter. You must not depend on the value you gave it earlier.
You might want to fill in XXXXX.
EXAMPLES
This is an example for an ISA bus interface. The values of portid and irqid should be
saved in the softc of the device after these calls.
struct resource *portres, irqres;
int portid, irqid, value;
#define REG1_OFFSET 0
portid = 0; /* use the first port resource */
irqid = 0; /* use the first interrupt resource */
portres = bus_alloc_resource(dev, SYS_RES_IOPORT, &portid,
0ul, ~0ul, 32, RF_ACTIVE);
irqres = bus_alloc_resource(dev, SYS_RES_IRQ, &irqid,
0ul, ~0ul, 1, RF_ACTIVE | RF_SHAREABLE);
value = bus_space_read_1( rman_get_bustag(portres),
rman_get_bustag(portres), REG1_OFFSET );
This is an example for a PCI bus interface. We assume that
for this particular device the device registers are available
through PIO instructions or have been mapped into the PCI
memory space. We can choose which method we want to use by
setting the rid value to the appropriate offset in the PCI
configuration that has the IO port or memory information.
struct resource *portres;
int portid, value;
#define REG1_OFFSET 0
#define LOMEM 0x10
#define LOIO 0x14
if( use_io ){
portid = LOIO;
} else {
portid = LOMEM;
}
portres = bus_alloc_resource(dev, SYS_RES_IOPORT, &portid,
0ul, ~0ul, 32, RF_ACTIVE);
value = bus_space_read_1( rman_get_bustag(portres),
rman_get_bustag(portres), REG1_OFFSET );
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