On Tue, Mar 20, 2012 at 10:46 AM, Saravana Kannan <skan...@codeaurora.org> wrote: > On Tue, March 20, 2012 7:02 am, Shawn Guo wrote: >> On Thu, Mar 15, 2012 at 11:11:19PM -0700, Mike Turquette wrote: >> ... >>> +struct clk_ops { >>> + int (*prepare)(struct clk_hw *hw); >>> + void (*unprepare)(struct clk_hw *hw); >>> + int (*enable)(struct clk_hw *hw); >>> + void (*disable)(struct clk_hw *hw); >>> + int (*is_enabled)(struct clk_hw *hw); >>> + unsigned long (*recalc_rate)(struct clk_hw *hw, >>> + unsigned long parent_rate); >> >> I believe I have heard people love the interface with parent_rate >> passed in. I love that too. But I would like to ask the same thing >> on .round_rate and .set_rate as well for the same reason why we have >> it for .recalc_rate. > > In my case, for most clocks, set rate involves reparenting. So, what does > passing parent_rate for these even mean? Passing parent_rate seems more > apt for recalc_rate since it's called when the parent rate changes -- so, > the actual parent itself is not expected to change.
>From my conversations with folks across many platforms, I think that the way your clock tree expects to change rates is the exception, not the rule. As such you should just ignore the parent_rate parameter as it useless to you. > I could ignore the parameter, but just wondering how many of the others > see value in this. And if we do add this parameter, it shouldn't be made > mandatory for the platform driver to use it (due to other assumptions the > clock framework might make). >From my rough census of folks that actually need .set_rate support, I think that everyone except MSM could benefit from this. Your concept of clk_set_rate is everyone else's clk_set_parent. Ignoring the new parameter should cause you no harm. It does make me wonder if it would be a good idea to pass in the parent rate for .set_parent, which is analogous to .set_rate in many ways. Regards, Mike > -Saravana _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev