On Wed, Feb 05, 2003 at 11:39:27AM +0100, Jules Bj?rn Colding wrote:
> On Wed, 2003-02-05 at 10:04, Erik Mouw wrote:
> > Don't fiddle with the PCI config space like that. We have the function
> > pci_write_config_byte() and friends for that. If you use those
> > functions, your driver will be portable, so it will work without
> > changing a single line of code the minute you put it in a PowerPC
> > machine. Another advantage is that using the pci_*() functions make
> > your code much more readable.
>
> I would love to do that, but I need a struct pci_dev before I can use
> pci_write_config_byte() and friends. To find a pci_dev (with
> pci_find_device() I think) I need a vendor and device id. My problem is
> that I don't have these. My device is a CR16MCS9 (see google) which has
> been bolted onto the PCI/ISA bridge. This device reports no vendor or
> device id to the system, well.. maybe it does, but then I can't find it.
>
> I can therefore not see how I can get a pci_dev pointer and thought that
> my only solution was to write directly to the pci registers. Is there
> another way around this problem ?
Yes. The CR16MCS9 is bolted to the PCI/ISA bridge. In order to fiddle
with it, you need to talk to the bridge. The bridge has a PCI ID, so
you can get the a struct pci_dev. (I suppose your PCI/ISA bridge is
something like the PLX 9080). There are several ways to get a struct
pci_dev, but the preferred way is to use a PCI ID table:
static int __devinit my_init_one (struct pci_dev *pdev, const
struct pci_device_id *ent)
{
int rv;
rv = pci_enable_device(pdev);
/* all other initialisation, like pci_reserve_regions() */
return 0;
}
static void __devexit my_remove_one (struct pci_dev *pdev)
{
pci_release_regions(pdev);
}
const static struct pci_device_id my_pci_tbl[] __devinitdata =
{
{ PCI_VENDOR_ID_MYCARD, PCI_DEVICE_ID_MYCARD, PCI_ANY_ID, PCI_ANY_ID, },
{ 0, }
};
MODULE_DEVICE_TABLE(pci, my_pci_tbl);
static struct pci_driver my_driver = {
name: MY_NAME,
id_table: my_pci_tbl,
probe: my_init_one,
remove: my_remove_one,
};
static int __init my_init_module (void)
{
return pci_module_init(&my_driver);
}
static void __exit my_exit_module (void)
{
pci_unregister_driver(&my_driver);
}
module_init(my_init_module);
module_exit(my_exit_module);
Another way to get a struct pci_dev is pci_find_device(), which can be
called with a NULL parameter to start a new search. Just run "make
psdocs" in your kernel tree, and you'll get
Documentation/DocBook/kernel-api.ps, which documents the Linux PCI
interface (among others).
Erik
--
J.A.K. (Erik) Mouw
Email: J.A.K.Mouw@its.tudelft.nl mouw@nl.linux.org
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