From mboxrd@z Thu Jan 1 00:00:00 1970 From: bilhuang@nvidia.com (Bill Huang) Date: Fri, 15 Mar 2013 19:23:19 -0700 Subject: [RFC 1/1] clk: Add notifier support in clk_prepare_enable/clk_disable_unprepare In-Reply-To: References: <1363151317.3311.9.camel@bilhuang-vm1> <51400D9D.9060305@wwwdotorg.org> <1363153204.3311.14.camel@bilhuang-vm1> <5140C12A.4060900@wwwdotorg.org> <1363227311.3311.30.camel@bilhuang-vm1> <20130314092132.GE18519@tbergstrom-lnx.Nvidia.com> <1363253287.3311.32.camel@bilhuang-vm1> <51420EBB.7080503@wwwdotorg.org> <1363310454.3311.44.camel@bilhuang-vm1> <5142B027.4040403@wwwdotorg.org> <20130315093951.GV18519@tbergstrom-lnx.Nvidia.com> <1363349206.5827.10.camel@bilhuang-vm1> Message-ID: <1363400599.2879.18.camel@bilhuang-vm1> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, 2013-03-15 at 20:33 +0800, Ulf Hansson wrote: > I guess you did not fully got what I meant with "dvfs clock type". It > will not affect the clock API. But instead the dvfs is handled by > implementing a specific clk hw type. So the same thing is accomplished > as with clk notifiers, no changes should be needed to device drivers. > > The difference is only that no notifiers will be needed, and all the > dvfs stuff will be handled in the clk hw instead. It will mean that we > will bundle dvfs stuff into the clock drivers, instead of separating > the code outside the clock drivers. But, on the other hand no > notifiers will be needed. > Oh yes I misunderstand your origin point, but my thought is using existing devfreq framework as frequency/voltage policy driver instead of creating another one in clock driver and that's why I think we need the notifier work. By the way, some centralized DVFS implementation like Tegra's VDD_CORE rail has association with tens of clocks which will need to be taken care specially if we're doing those in clock driver I think. > Kind regards > Ulf Hansson