pci-mvebu driver on km_kirkwood
Gerlando Falauto
gerlando.falauto at keymile.com
Mon Nov 4 09:49:59 EST 2013
Hi folks,
thank you for your patience...
So, thanks to Thierry's example:
>
https://gitorious.org/thierryreding/linux/commit/b85c03d73288f6e376fc158ceac30f29680b4192
and Jason's explanation:
> The reg must encode the bus number according to the OF format:
>
> 33222222 22221111 11111100 00000000
> 10987654 32109876 54321098 76543210
> phys.hi cell: npt000ss bbbbbbbb dddddfff rrrrrrrr
> phys.mid cell: hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh
> phys.lo cell: llllllll llllllll llllllll llllllll
>
> bbbbbbbb is the 8-bit Bus Number
> ddddd is the 5-bit Device Number
> fff is the 3-bit Function Number
>
> Others are 0.
I'm finally starting to make some sense out of this, and I checked that
Jason's statement is indeed true, at least on 3.10:
> Device tree can include the discovered PCI devices, you have to use
> the special reg encoding and all that weirdness, but it does work. The
> of_node will be attached to the struct pci device automatically.
[Hi latency was also due to other activities, not just the low
throughput of my brain cells] ;-)
I have one last question for Thierry though: what's the point of things
such as
+ pci at 0,0 {
+ compatible = "opencores,spi";
(apart from clarity, of course)?
I mean, wouldn't the driver be bound to the device through its PCI
vendor ID / device ID?
Are we also supposed to register a platform driver based on a compatible
string instead?
Thanks again guys!
Gerlando
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