On Sun, Oct 16, 2011 at 07:55:21PM +0200, Sascha Hauer wrote: > On Fri, Oct 14, 2011 at 06:32:33PM +0800, Richard Zhao wrote: > > On Fri, Oct 14, 2011 at 11:05:04AM +0100, Mark Brown wrote: > > > On Fri, Oct 14, 2011 at 04:10:26PM +0800, Richard Zhao wrote: > > > > On Thu, Sep 22, 2011 at 03:26:56PM -0700, Mike Turquette wrote: > > > > > > snip essentially Mike's entire mail - *please* delete irrelevant quotes > > > from your replies, it makes it very much easier to find the new text in > > > your mail and is much more friendly to people reading mail on mobile > > > devices. > > I snip not enough? sorry for that. I'll be carefull. > > > > > > > > +static int __clk_enable(struct clk *clk) > > > > > +{ > > > > > > > Could you expose __clk_enable/__clk_disable? I find it hard to implement > > > > clk group. clk group means, when a major clk enable/disable, it want a > > > > set > > > > of other clks enable/disable accordingly. > > > > > > Shouldn't this be something the core is implementing? I'd strongly > > > expect that the clock drivers are relatively dumb and delegate all the > > > decision making to the core API. Otherwise it's going to be hard for > > > the core to implement any logic that involves working with more than one > > > clock like rate change notification, or guarantee that driver requests > > > made through the API are satisfied, as the state of the clocks will be > > > changing underneath it. > > From my point of view, the first step of generic clk can be, easy to adopt > > features of clocks in current mainline git. > > Back to the clk group, I have a patch based on Sascha's work. > > http://git.linaro.org/gitweb?p=people/riczhao/linux-2.6.git;a=shortlog;h=refs/heads/imx-clk > > I thought further about this and a clock group is not something we want > to have at all. Clocks are supposed to be arranged in a tree and > grouping clocks together violates this which leads to problems. > This grouping should be done at driver level, so when a driver needs > more than one clock it should request them all, maybe with a clk_get_all > helper function. clock group is not limited to help driver get clock. It refects clock dependency. For example, devices that possible access to on-chip RAM, depend on OCRAM clock. On imx53, VPU depends on OCRAM clock, even when VPU does not use OCRAM.
Thanks Richard > > Sascha > > -- > Pengutronix e.K. | | > Industrial Linux Solutions | http://www.pengutronix.de/ | > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-ker...@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev