[PATCH v5 4/4] clk: basic clock hardware types

Turquette, Mike mturquette at ti.com
Fri Mar 9 23:38:39 UTC 2012

On Mon, Mar 5, 2012 at 2:17 AM, Andrew Lunn <andrew at lunn.ch> wrote:
>> > I think i can wrap your simple gate clock, to make my "complex" gate
>> > clock. What would help is if you would EXPORT_SYMBOL_GPL
>> > clk_gate_enable() and clk_gate_disable(), since they do exactly what i
>> > want. I can then build my own clk_ops structure, with my own
>> > unprepare() function. I would probably use DEFINE_CLK_GATE as is, and
>> > then at run time, before calling __clk_init() overwrite the .ops with
>> > my own version.
>> Maybe I don't get your point, but clk_unprepare should be used when
>> you have to sleep to disable your clock. When clk_gate_disable() is
>> exactly why do you want to use clk_unprepare instead of clk_disable?
> I'm trying to avoid having to implement a new clock provider. The
> whole point of the generic clk code is to consolidate code. It seems
> silly to create a new clk provider which is 95% identical to Mike's
> gated provider, if i can avoid it.

I will export the operations in my next patchset, but I'm concerned
over how useful this might be...

Using your example of struct clk_gate, both clk_gate_enable and
clk_gate_disable call to_clk_gate.  So you would either have to re-use
struct clk_gate for your own needs (which involves hacking up a
specific struct clk_gate_foo_ops for your needs) or you could not use
struct clk_gate and pack your data identically (struct clk_hw must be
the first member) which is too horrible to imagine.

Hmm, or you could re-use struct clk_gate but provide your own struct
clk_ops AND your own registration functions (since you won't be able
to pass in the ops to your clk_register_gate).  So that sounds sane,
if a bit convoluted.  It does re-use code though...


> If i stuff it into clk_disable(), it means i cannot use the basic gate
> clock Mike provides in the generic clock framework. Which is a shame,
> since it does exactly what i want in terms of gating the clock.
> If i can use unprepare(), which basic gate does not use, i can use
> Mikes code, and just extend it. It is there, it is unused, so why not
> use it?
>    Andrew

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