On 10/10/07, David Gibson <[EMAIL PROTECTED]> wrote:
> > My main concern is that I don't like the implicit numbering that
> > occurs simply based on the order of devices in the device tree. If
> > the probe algorithm ever changes to parse in reverse order or
> > something reorders the tree, then the device numbers also change. :-(
>
> Way of the future, apparently, everything's supposed to use udev to
> give things logical names. No, I'm not thrilled at the prospect
> either.
...
So in the OF aliases approach, would udev need to read the aliases
node when assigning names to devices?
>
> > I'd rather be explicit. In fact I've already been bitten by this
> > where the mpc5200 has 6 PSC, each of which can be configured as a
> > serial port. However, I've got access to 3 different boards; each of
> > which has the logical port numbers 100% unrelated to the 'cell'
> > number.
>
> In any case, this can't really belong in a *device* binding. Because
> the numbering has to cross devices of the same basic type, but
> different implementations. Where "basic type" is based on how device
> names are allocated, and is thus inherently Linux specific.
Okay, that makes sense.
> > > Segher's suggestion of using OF-style aliases for this is a fairly
> > > good one, actually. I just need to get to implementing it...
> >
> > /me needs to look up what that look like and how I would use it. My
> > knowledge of OF is sadly lacking.
>
> Short version by example:
> / {
> /* ... */
> aliases {
> hd = "/[EMAIL PROTECTED]/[EMAIL PROTECTED]/....";
> enet0 = "/soc/[EMAIL PROTECTED]";
> enet1 = "/soc/[EMAIL PROTECTED]";
> enet2 = "/[EMAIL PROTECTED]/isa/[EMAIL PROTECTED]"
> ttya = "/soc/[EMAIL PROTECTED]";
> ttyb = "/pci/isa/[EMAIL PROTECTED]";
> }
> }
Ah, my plan worked... I got you to teach me about OF aliases and I
have to do any work myself. :-)
Hmm, yes that would provide the information nicely. As long as the
data is in the tree, I'm pretty happy.
Cheers,
g.
>
> --
> David Gibson | I'll have my music baroque, and my code
> david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
> | _way_ _around_!
> http://www.ozlabs.org/~dgibson
>
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
[EMAIL PROTECTED]
(403) 399-0195
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