On Wed, Apr 25, 2012 at 06:33:26, Paul Walmsley wrote: > Hello Vaibhav, Afzal, Vaibhav, > > On Tue, 3 Apr 2012, Vaibhav Hiremath wrote: > > > AM33XX clock implementation is different than any existing OMAP > > family of devices. Although DPLL module is similar to OMAP4 > > device, but the usage is very much different than OMAP4. > > AM33XX has different peripheral set and each module gets > > integrated to the clock framework differently than OMAP > > family of devices. > > > > This patch adds full Clock tree data for AM33XX family > > of devices and also integrates it into existing OMAP framework. > > What do you think about the possibility of removing all of the leaf clocks > that have AM33XX_MODULEMODE_SWCTRL as their .enable_bit, assuming there > are no .fixed_div or .clksel* fields associated with the clocks? > > In theory, I don't think they are needed. The drivers should be using > runtime PM, and that should enable and disable the module via the hwmod > code, rather than the clock code. > > Of course some clocks would still be needed for the main_clk fields for > the hwmods, but the hwmods should be able to use the leaf clock's parent > clocks for that. > > That would save quite a few lines of data. And I think Benoît is planning > to do that for OMAP4+. > > What do you think? > Paul, Yes, theoretically it is possible to do it. But it will also break some of the existing things, like, 1. DebugFS clock interface I believe, with this change, you will not have all the leaf nodes as part of clock tree, so they will not be populated in /debug/clock/ 2. Enable and disable of the module is one part, but what about, changing the rate of the clock (followparent_recalc)? With the proper and complete clock tree, you can traverse the clock and driver code doesn't need to know about parent. Driver can simply call clk_set_rate() on leaf clock, and clock tree will handle it. If at all we take this path, we have to build the clk node runtime (on-the-fly), AND/OR add new pm_runtime_set_rate() api. Are you available on IRC chat anytime? We can discuss on this and align quickly. I am available on linux-omap irc channel (with the name = "hvaibhav") Thanks, Vaibhav > > - Paul > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
