Eric Clément wrote:
I create a pci device which I want to interact with Linux for a user
application. This pci device is a FPGA. I create a kernel module for
communication kernel - user space and now I want to send settings
information to this pci device.
Ive been looking for a PCI card with a user-programmable FPGA, tell us more.
does it have a hardwired PCI interface (ie already in silicon)
if so, it should have a pci-config-space (64 bytes, i think), and
could be programmable thru that.
I need to use (I/O memory) to do that. But I don't how. I can't get
the base address with pci_read_config and after that I am confuse.
yeah - something doesnt add up. Does it appear in /sys ?
$> file /sys/bus/pci/devices/0000\:00\:00.0/config
/sys/bus/pci/devices/0000:00:00.0/config: data
I
think I can use both function outb or writeb to send information but I
don't know which is better.
Read LDD-3, both ch 3(chr-driver), 8-(mem) IIRC.
The choice between them is basically ioport or iomem,
and I think its somewhat dicated by the processor.
x86 has a separate IO-addr-space so inb, outb just work,
68k does not, so those boards must map IO ops into memory,
and U must use ioremap to tell the kernel where the IO-space is.
But I dont have one of these, and U shouldnt just take my word for it.
what kind of board are u using.
outb seem to be Intel specific and writeb need to map I/0 memory with ioremap
I think youve got ioremap usage backwards.
I have intel board, im using inb,outb, and have no ioremap,
and Im getting expected results.
Which method is more standard for a pci device (portable)?
On 6/22/05, Christophe Lucas <clucas@xxxxxxxxxxxxx> wrote:
Eric Clément (clement.eric@xxxxxxxxx) wrote:
Hi,
I know the base address (I/O memory) of my device, but I don't know
how to write information to the device.
Which fonction shoud I use :
outb, writeb or ... ?
I think you should use outb();
You can see how is declared writeb() for x86 :
http://lxr.linux.no/source/include/asm-i386/io.h#L165
But I think you should give more information to us to be able to help
you.
- Christophe
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