|
Hi,
>a) Do I need to do a request_region()/release_region()
for both
>addresses around these lines of code ?
Yes u have to. U can find out the range of address(s) that u need to map
and then request it.
>/* Write to the pci configuration address register
*/
> outl(0x80000000 | (0xc << 11) | (0x40 << 2),
0xcf8)
U shouldnt do it like this.
U hv to use pci_read/write_config_byte/word to read/write the config
data.
>b) Do I need to disable interrupts while writing to these
registers ?
Depends on the scenario...usually NO.
>c) Do I need to reset 0xcf8 after having written to 0xcfc
?
Can't think of any reason.
Geeks, correct me if im wrong anywhere.
Regds.
-nagaraj
\(*_*)/
-----Original Message-----
From: Jules Bjørn
Colding [mailto:JuBColding@yorkref.com]
Sent: Tue 2/4/2003 5:04 PM
To: Kernel Newbies
Cc:
Subject: PCI register
questions..
Hi all,
My problem is that I have to write a driver for
a co-processor on a
board which we will use, at my work, as an embedded
controller. The
board itself is based upon a 486. The co-processor has been
bolted onto
the PCI/ISA bridge with nine of its pins.
I am almost
where I can start to access it but I have a few
remaining
questions.
This is what I know:
1) I have to enable
all GPIOs on the board before I can access the
co-processor. This is done
by writing 0x2 to register offset 0x40 at the
PCI data configuration
register. Before doing so I have to enable reads
and writes to this
register. These two lines does that:
/* Write to the pci configuration
address register */
outl(0x80000000 | (0xc << 11) | (0x40 <<
2), 0xcf8)
/* Write to the pci configuration data register
*/
outb(0x02, 0xcfc)
But..
a) Do I need to do a
request_region()/release_region() for both
addresses around these lines of
code ?
b) Do I need to disable interrupts while writing to these
registers ?
c) Do I need to reset 0xcf8 after having written to 0xcfc
?
Thanks a lot in advance!
jules
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