My question was more about general concept of PCI device driver.
I didn't see how a driver can't interact with a PCI card with base
address space I/O.
I just saw that base address are define when the system boot. (Is that right ?)
So, if that is right, I can use inb/outb to access I/O PCI space.
If not, how can I config a proper base address to avoid confusion ?
> > >
> > > >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.
> > >
> > yes, I can't config it.
> oups, i can config it, sorry :)
> > The problem is to interact with the device. The FPGA do some calcul
> > and I need to change some value (register) of the algo that it
> > perform.
> >
> > Here a partial code :
> >
> > u32 io_addr;
> > #define SLOPE_REGISTER 0x04
> > ...
> > pci_read_config_dword(dev, PCI_BASE_ADDRESS_0, &io_addr);
> > ...
> > if(PCI_BASE_ADDRESS_SPACE_IO& io_addr)
> > {
> > //here I want set a register
> > u8 slope = 10;
> > outb(slope , io_addr + SLOPE_REGISTER ); //can I do 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
> > > >>
> > > >>
> > > >>
> > > >
> > > >--
> > > >Kernelnewbies: Help each other learn about the Linux kernel.
> > > >Archive: http://mail.nl.linux.org/kernelnewbies/
> > > >FAQ: http://kernelnewbies.org/faq/
> > > >
> > > >
> > > >
> > >
> > >
> >
>
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