Messages in this thread Patch in this message | | | Date | Fri, 26 Sep 2014 17:15:00 -0700 | From | Stephen Boyd <> | Subject | Re: [PATCH v13 0/9] Per-user clock constraints |
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On 09/26/14 16:20, Mike Turquette wrote: > Quoting Tomeu Vizoso (2014-09-26 01:09:20) >> On 09/26/2014 03:29 AM, Stephen Boyd wrote: >> >>> We already have the consumer/provider split in the struct clk_hw and >>> struct clk separation. Why don't we just use struct clk_hw throughout >>> the provider APIs? The only op that isn't doing this is determine_rate() >>> which might be able to accept a flag day. Otherwise we rename it to >>> something else and migrate everyone over to a different named function >>> that doesn't take a struct clk **. Then we introduce new APIs for the >>> providers to use that are struct clk_hw focused instead of struct clk >>> focused and migrate them too. The benefit being that we get proper >>> review of this stuff because the patches are small. We can let >>> coccinelle do it too. > I have been opposed to mucking with clk_hw before, but that was because > the goal was never clear. Now that we know that we're trying to split > the API then it might be reasonable to use it. > > Stephen, does your above proposal still allow for unique struct clk > cookies for each user of a clock? > >
Yes. The clkdev code would know that it's getting clk_hw pointers back from the provider instead of struct clk pointers because it uses a different callback:
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index bacc06ff939b..76c356b779d1 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -2337,6 +2337,7 @@ struct of_clk_provider { struct device_node *node; struct clk *(*get)(struct of_phandle_args *clkspec, void *data); + struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data); void *data; };
It would test for the presence of the get_hw callback and then fall back to the get callback. Similarly we would have a clk_hw pointer in the clkdev lookup structure. Once clkdev has the hw pointer it can ask the ccf to generate a struct clk cookie. This would happen either in __of_clk_get_from_provider() or clk_get_sys() depending on if we're using DT or not.
The clk_hw structure will need to be updated to have a pointer to clk_core. During the transition we would have struct clk and struct clk_core next to each other in struct clk_hw. Eventually once we convert all drivers we can remove struct clk from clk_hw. This would require getting rid of the DEFINE_CLK macro in clk-private.h though.
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