ARM clock API to PowerPC
benh at kernel.crashing.org
Thu Aug 13 09:15:22 EST 2009
> The problem is that you've got a chip which has a clock tree of its own
> which could benefit from using the clock API internally (in this case
> because it helps generalisation to the case where it's on the CPU for
> the MMC block to be able to just use the clock API for its clocks).
> Ideally the MFD core for the tmio would be able to extend the clock tree
> so that the MMC driver can work without knowing what sort of device it's
> part of. Having the platform know about the clocks in the MFD means
> teaching each platform that might use the chip about the clocking
> structure of the chip in some way. However, there's a concern about
> making the clock API too heavyweight for the on-SoC clocks that are the
> major application. Things like per-clock memory consumption are an
> issue on bigger chips.
Right. Well, my proposal of linkage of clock providers via the
device-tree would definitely solve that problem for us at least,
provided the various parts of the chip are represented as nodes in the
> > Having more "generic" clock providers for off-SoC clock chips is an idea
> > that went through my mind but you may be right that it's not necessarily
> > something we need to cater for initially, it can be handled by platform
> > for now easily enough.
> So long as that's clear to device tree users that should be fine.
That's my thought too.
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