Microblaze Linux support for AXI PCIe RC is missing?

memset · ‎12-23-2009

Is where Linux driver available for LogiCORE IP AXI Bridge for PCI Root Complex (PCI host/PCI bridge)?

Datasheet DS820 says this core is supported by Linux, but in fact, its RC functionality can't be used in embdded Linux due to lack of the driver. Old PCI host bridge driver found in both mainline kernel and git.xilinx.com kernel doesn't seems to have any support for AXI PCIe RC.

Are any ready to use solutions exiests for this?

Thank you.

linnj · ‎09-10-2008

Work is still going on for PCIe to make it work properly in a software system. We are debating about putting it into the tree as a development (not released) driver.

Thanks.

John Linn

memset · ‎12-23-2009

Thanks for the reply, John. That's good news.

Is it possible to get this (incomplete) driver now?

It should be better anyway than reinventing the wheel by myself from the scratch.

Thanks!

linnj · ‎09-10-2008

Sure, we're discussing that now and yes I think we can. We will mark it as a development driver and not released so there would not be any support from Xilinx on it yet.

John Linn

memset · ‎12-23-2009

Good! But how to get it?
Should I wait for it to appear in linux-xlnx.git, or its going to be available as separate download?
Thank you very much!

memset · ‎12-23-2009

Now I can see the AXI PCIe RC driver for Microblaze in master-next of linux-xlnx.git.

Big thanks for the opportunity to have early access to this code!

linnj · ‎09-10-2008

Great! Let us know how it goes. The device tree generator repo was updated to help generate a device tree. Please remember this is not a released driver and I need to document that on the wiki. Thanks.

John Linn

memset · ‎12-23-2009

I'v tried it and, in short words, it works.
I'v got a minor headache with adding this code to mainline 3.4.4 kernel used in my project, but finally it worked. I'm getting some difficulties with MSI's and the ranges property generated by new device tree generator looks like a hack and angers kernel dts compiler, but in general that driver is good enough to use.

A question left: is it possible to use (emulate?) PCI IO resource with AXI PCIe RC? All bridge's AXIBAR's are of memory type by their nature and I'v failed to mimic one them as IO window - both with my own driver and with this one.