Messages in this thread | | | Date | Tue, 31 Jan 2017 09:20:58 -0800 | From | Guenter Roeck <> | Subject | Re: [PATCH v2] clk: add more managed APIs |
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On Mon, Jan 30, 2017 at 04:59:57PM -0800, Dmitry Torokhov wrote: > On Mon, Jan 30, 2017 at 11:22:14AM -0800, Guenter Roeck wrote: > > On Mon, Jan 30, 2017 at 10:55:51AM -0800, Stephen Boyd wrote: > > > On 01/29, Dmitry Torokhov wrote: > > > > When converting a driver to managed resources it is desirable to be able to > > > > manage all resources in the same fashion. This change allows managing > > > > clocks in the same way we manage many other resources. > > > > > > Can you please add 'managing clock prepared and enabled state in > > > the same way'? > > > > > > The current wording makes it sound like we don't have > > > devm_clk_get() when we do. > > > > > > > > > > > This adds the following managed APIs: > > > > > > > > - devm_clk_prepare()/devm_clk_unprepare(); > > > > - devm_clk_prepare_enable()/devm_clk_disable_unprepare(). > > > > > > Wouldn't this be preceded by a devm_clk_get() call? Wouldn't it > > > be even shorter to have the APIs > > > > > > devm_clk_get_and_prepare()/devm_clk_unprepare_and_put() > > > devm_clk_get_and_prepare_enable()/devm_clk_disable_unprepare_and_put() > > > > > > instead? > > > > > In many cases I see > > > > devm_clk_get(clk1); > > devm_clk_get(clk2); > > clk_prepare_enable(clk1); > > clk_prepare_enable(clk2); > > > > Sometimes the calls are intertwined with setting the clock rates. > > > > devm_clk_get(clk); > > clk_set_rate(clk, rate); > > clk_prepare_enable(clk); > > > > Maybe the additional calls make sense; I can imagine they would. > > However, I personally would be a bit wary of changing the initialization > > order of multi-clock initializations, and I am not sure how a single call > > could address setting the rate ([devm_]clk_get_setrate_prepare_enable() > > seems like a bit too much). > > > > [ On a side note, why is there no clk_get_prepare_enable() and > > clk_get_prepare() ? Maybe it would be better to introduce those > > together with the matching devm_ functions in a separate patch > > if they are useful. ] > > > > > Is there any other subsystem that has similar functionality? > > > Regulators? GPIOs? Resets? I'm just curious if those subsystems > > > also need similar changes. > > > > > Ultimately yes, and most already do. If I recall correctly, I tried to > > introduce devm_ functions for regulators some time ago, but that was > > rejected with the comment that it would invite misuse. At the time > > I accepted that; today my reaction would be to counter that pretty much > > everything can be misused, and that the potential for misuse should not > > penaltize all the valid use cases. > > I think we should ping Mark again. The only thing we are achieving is > that everyone is using devm_add_action_or_reset() with wrappers around > regulator_put(). > regulator_get() has an equivalent devm_regulator_get(). Maybe it was since added, or I was thinking about a different function.
Guenter
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