Date: Thu, 17 Jul 1997 16:35:22 -0700 (PDT) From: Simon Shapiro <Shimon@i-Connect.Net> To: Stefan Esser <se@freebsd.org> Cc: freebsd-hackers@freebsd.org Subject: Re: pcireg.h lost children... ? Message-ID: <XFMail.970717212105.Shimon@i-Connect.Net> In-Reply-To: <19970716214222.61218@mi.uni-koeln.de>
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Hi Stefan Esser; On 16-Jul-97 you wrote:
... Excellent explanation deleted ...
It did, for a while, break compatability...
> I did not expect drivers to actually care for the class code
> or command register values of a device, since higher level
> code should take care of things ...
>
> What are you using those values for ?
In pci/dpt_pci.c:
dpt_pci_probe()
...
if ((dpt_id = (type & 0xffff0000) >> 16) == DPT_DEVICE_ID) {
/* This one appears to belong to us, but what is it? */
class = pci_conf_read(tag, PCI_CLASS_REG);
if (((class & PCI_CLASS_MASK) == PCI_CLASS_MASS_STORAGE) &&
((class & PCI_SUBCLASS_MASK) == PCI_SUBCLASS_MASS_STORAGE_SCSI) ) {
/* It is a SCSI storage device. How do talk to it? */
command = pci_conf_read(tag, PCI_COMMAND_STATUS_REG);
if ( ((command & PCI_COMMAND_MEM_ENABLE) == 0)
&& ((command & PCI_COMMAND_IO_ENABLE) == 0) ) {
printf("DPT: Cannot map the controller as memory, nor as I/O :-(\n");
return(NULL);
}
} else {
printf("DPT: Device is not Mass Storage, nor SCSI controller :-(\n");
return(NULL);
}
command = pci_conf_read(tag, PCI_COMMAND_STATUS_REG);
if ( (command & PCI_COMMAND_MASTER_ENABLE) == 0 ) {
printf("DPT: BUSMASTER disabled :-(\n");
return (NULL);
}
And in dpt_pci_attach()
...
io_base = 0;
vaddr = 0;
paddr = 0;
data = pci_conf_read(config_id, PCI_BASEADR0);
command = pci_conf_read(config_id, PCI_COMMAND_STATUS_REG);
if ( ((command & PCI_COMMAND_MEM_ENABLE) == 0)
|| (pci_map_mem(config_id, PCI_BASEADR0, &vaddr, &paddr) == 0) ) {
/* Either not memory mappable or mapping failed. Try I/O mapping */
if ((command & PCI_COMMAND_IO_ENABLE) == 0
|| (pci_map_port(config_id, PCI_BASEADR0, &io_base) == 0) ) {
free(dpt, M_DEVBUF);
printf ("dpt%d: Failed to map memory or I/O registers :-(\n", unit);
return;
}
}
Makes sense?
Simon
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