On Mon, Feb 09, 2009 at 06:44:40PM +0100, Davide Rizzo wrote:
> >> This driver is for user level programs to interact with system clocks.
> >> It allows to read and modify rates and parents, using virtual files.
> >> It requires the implementation of 2 additional functions in the clk interface:
> >> clk_for_each() and clk_name().
> >> Actually I implemented that functions only for Samsung S3C24xx platform.
> >
> > NAK.
> >
> >> + name = clk_get_name(clk);
> >
> > This implies that there is a 1:1 relationship between a 'name' and a
> > struct clk. No such thing exists (and where it does, it's being
> > eliminated in ARM because it's just plain and simple WRONG.)
>
> Not exactly, clk_get() could work in both way: a struct clk can be
> exactly identified by name and device id (like clk_get is acting now)
> or by full name, in the format clkname.device
You're not understanding the issue(s).
1. there is no 1:1 mapping between the identifiers (struct device +
connection ID) and the struct clk. It's actually a many-to-one
mapping.
That means there is _no_ name associated with a struct clk.
Conceptually, clk_get() gives you a struct clk for the struct device
and a connection ID. How that mapping is achieved isn't specified
in the API, all that's required is that such a mapping is performed.
It is _specifically_ intended that more than one set of {device,id}
pairs will map to the same clk.
So, now to insist that you can go from a struct clk to some kind of
string identifier for it is changing this - you're now requiring
that every struct clk has a unique name. This is not the case.
PXA, for instance, struct clk's are now completely nameless. They
have no identifier.
If you want to have a string identifier which works in every case,
this will:
sprintf(identifer, "%p", clk);
Or, I guess you could force every struct clk to have a 'sysfs_name'
field just to export them out via sysfs - and that'll be all that
it's used for.
2. there is no generic way to walk a set of struct clk's - indeed, there
may be no list of them (and there exists implmentations where that is
true) and the only list which does exist is a set ID to clk mapping
structures.
> Otherwise, what do you suggest to enumerate and distinguish all system
> clocks ?
There exists no such concept in the API, what you're asking for is
implementation specific.
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