PCI hotplug supported on ARM (Kirkwood)?

PCI hotplug supported on ARM (Kirkwood)?

[Dieter Kiermaier]

Hi list,

is it possible to boot a FPGA which is connected to an PCI bus on a kirkwood cpu (via a pcie->pci bridge)
at runtime (I call it hotplug)?

And after booting the FPGA e.g. via slave serial protocol loading the pci driver and access the device?
This would be much easier to handle than flashing the fpga using u-boot.

Is there any special framework I have to use? How can I tell the kernel to reenumerate the bus and reasign
the pci resources?

I have googled a lot and also tried to find something at newsgroups or mailinglists but I haven't found some
valuable information - at least not for me ;).
Is this possible?

Many thanks,
Dieter

PCI hotplug supported on ARM (Kirkwood)?

[Alexander Clouter]

Dieter Kiermaier <dk-arm-linux@gmx.de> wrote:
> 
> is it possible to boot a FPGA which is connected to an PCI bus on a 
> kirkwood cpu (via a pcie->pci bridge) at runtime (I call it hotplug)?
> 
> And after booting the FPGA e.g. via slave serial protocol loading the 
> pci driver and access the device? This would be much easier to handle 
> than flashing the fpga using u-boot.
> 
> Is there any special framework I have to use? How can I tell the 
> kernel to reenumerate the bus and reasign the pci resources?
> 
> I have googled a lot and also tried to find something at newsgroups or 
> mailinglists but I haven't found some valuable information - at least 
> not for me ;). Is this possible?
> 
I tried tackling this on my board by creating a new 'bus' and trying to 
work around making the FPGA 'hotplugable' that way.  As the bus would 
know about the process of reprogramming the FPGA, it could cleanly 
unload and reload everything.

http://marc.info/?l=linux-kernel&m=124441477117607&w=2

Never did get it to work and no one expressed any real interest in it 
for the platform sadly; so I drifted off looking for other geeky things 
to do.

I am still personally keener on the bus model, but Geert suggested I 
lump for a MFD.

Whatever you do, if you can keep me in the loop then I can nick your 
ideas/code and maybe get back into tinkering with my ARM board, that's 
if I stop bricking my MIPS boards :-/

Cheers

-- 
Alexander Clouter
.sigmonster says: There's a lot to be said for not saying a lot.

PCI hotplug supported on ARM (Kirkwood)? - fakephp?

[Dieter Kiermaier]

Am Donnerstag 12 November 2009 20:01:32 schrieb Alexander Clouter:

> Dieter Kiermaier <dk-arm-linux@gmx.de> wrote:
> > 
> > is it possible to boot a FPGA which is connected to an PCI bus on a 
> > kirkwood cpu (via a pcie->pci bridge) at runtime (I call it hotplug)?
> > 
> > And after booting the FPGA e.g. via slave serial protocol loading the 
> > pci driver and access the device? This would be much easier to handle 
> > than flashing the fpga using u-boot.
> > 
> > Is there any special framework I have to use? How can I tell the 
> > kernel to reenumerate the bus and reasign the pci resources?
> > 
> > I have googled a lot and also tried to find something at newsgroups or 
> > mailinglists but I haven't found some valuable information - at least 
> > not for me ;). Is this possible?
> > 
> I tried tackling this on my board by creating a new 'bus' and trying to 
> work around making the FPGA 'hotplugable' that way.  As the bus would 
> know about the process of reprogramming the FPGA, it could cleanly 
> unload and reload everything.
> 
> http://marc.info/?l=linux-kernel&m=124441477117607&w=2
> 
> Never did get it to work and no one expressed any real interest in it 
> for the platform sadly; so I drifted off looking for other geeky things 
> to do.
> 
> I am still personally keener on the bus model, but Geert suggested I 
> lump for a MFD.

Hm, it looks like fakephp is what I was looking for but I see no way to compile
this module on my arm (kirkwood).

Does anybody know a way to compile it?

Many thanks,
Dieter



> 
> Whatever you do, if you can keep me in the loop then I can nick your 
> ideas/code and maybe get back into tinkering with my ARM board, that's 
> if I stop bricking my MIPS boards :-/
> 
> Cheers
> 

PCI hotplug supported on ARM (Kirkwood)? - fakephp?

[Dieter Kiermaier]

Am Freitag 13 November 2009 12:21:43 schrieb Dieter Kiermaier:
> Am Donnerstag 12 November 2009 20:01:32 schrieb Alexander Clouter:
> 
> > Dieter Kiermaier <dk-arm-linux@gmx.de> wrote:
> > > 
> > > is it possible to boot a FPGA which is connected to an PCI bus on a 
> > > kirkwood cpu (via a pcie->pci bridge) at runtime (I call it hotplug)?
> > > 
> > > And after booting the FPGA e.g. via slave serial protocol loading the 
> > > pci driver and access the device? This would be much easier to handle 
> > > than flashing the fpga using u-boot.
> > > 
> > > Is there any special framework I have to use? How can I tell the 
> > > kernel to reenumerate the bus and reasign the pci resources?
> > > 
> > > I have googled a lot and also tried to find something at newsgroups or 
> > > mailinglists but I haven't found some valuable information - at least 
> > > not for me ;). Is this possible?
> > > 
> > I tried tackling this on my board by creating a new 'bus' and trying to 
> > work around making the FPGA 'hotplugable' that way.  As the bus would 
> > know about the process of reprogramming the FPGA, it could cleanly 
> > unload and reload everything.
> > 
> > http://marc.info/?l=linux-kernel&m=124441477117607&w=2

Hm, your link seems to be down. Do you have a newer version of your code
somewhere?

> > 
> > Never did get it to work and no one expressed any real interest in it 
> > for the platform sadly; so I drifted off looking for other geeky things 
> > to do.
> > 
> > I am still personally keener on the bus model, but Geert suggested I 
> > lump for a MFD.
> 
> Hm, it looks like fakephp is what I was looking for but I see no way to compile
> this module on my arm (kirkwood).
> 

fakephp seems to be integrated / ported into the pci layer?
I have a /sys/bus/pci interface:

It is possible to deactivate devices by doing:
echo 1 > /sys/bus/pci/devices/0000\:01\:08.0/remove

But it looks like  there is no way of reactivating /rescanning it?

I've tried
echo 1 > /sys/bus/pci/rescan
but without any success.

Does anybody have an idea?

Many thanks,
Dieter





> Does anybody know a way to compile it?
> 
> Many thanks,
> Dieter
> 
> 
> 
> > 
> > Whatever you do, if you can keep me in the loop then I can nick your 
> > ideas/code and maybe get back into tinkering with my ARM board, that's 
> > if I stop bricking my MIPS boards :-/
> > 
> > Cheers
> > 
> 
> 
> 
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