Messages in this thread | | | Date | Wed, 29 Jul 2009 21:51:30 +0900 | Subject | Re: MMC: Make the configuration memory resource optional | From | Magnus Damm <> |
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On Wed, Jul 29, 2009 at 9:42 PM, Mark Brown<broonie@opensource.wolfsonmicro.com> wrote: > On Wed, Jul 29, 2009 at 09:27:54PM +0900, Magnus Damm wrote: >> On Wed, Jul 29, 2009 at 8:58 PM, Mark >> Brown<broonie@opensource.wolfsonmicro.com> wrote: > >> > While it's true that this doesn't bother SoCs the fact that most clock >> > API implementations don't allow any off-chip drivers to register clocks >> > renders the clock API essentially unusable for fairly large parts of the > >> Yeah, clocks outside the SoC are not well supported today. From what >> I've seen, most embedded boards come with external chips for cameras, >> audio codecs and/or phy devices. These devices often get their clocks >> from the main SoC. Allowing the drivers for such chips to use the >> clock framework to register clocks for internal divisors would allow >> driver writers to write better code which in turn would make life >> easier for most people hacking on embedded kernels. > > That's not actually abundantly clear for the audio stuff, or rather the > audio stuff would like additional features like constraint based > configuration.
Without knowing too much about this, wouldn't camera sensors want similar features?
>> The problem with the clock framework API is that the data structures >> varies depending on implementation. So the ops callback structure on >> SuperH is different compared to ARM. I suspect that adding generic >> clocklib support across the architectures will take quite a bit of >> time to implement propely. > > Indeed. It's actually much worse than you say, each individual ARM > architecture has its own clock API implementation of varying quality and > of course there are architectures that don't do the clock API at all.
Yeah. This is exactly why I don't want to block on the clocklib implementation.
Cheers,
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