[PATCH v13 3/6] clk: Make clk API return per-user struct clk instances

On 02/02/15 14:41, Mike Turquette wrote:

Quoting Tero Kristo (2015-02-02 11:32:01)

quoted

On 02/01/2015 11:24 PM, Mike Turquette wrote:

quoted

AFAICT this doesn't break anything, but booting on OMAP3+ results in
noisy WARNs.

I think the correct fix is to replace clk_bypass and clk_ref pointers
with a simple integer parent_index. In fact we already have this index.
See how the pointers are populated in ti_clk_register_dpll:

The problem is we still need to be able to get runtime parent clock 
rates (the parent rate may change also), so simple index value is not 
sufficient. We need a handle of some sort to the bypass/ref clocks. The 
DPLL code generally requires knowledge of the bypass + reference clock 
rates to work properly, as it calculates the M/N values based on these.

We can maybe introduce something like of_clk_get_parent_rate, as we have
analogous stuff for getting parent names and indexes. Without
introducing a new helper you could probably just do:

	clk_ref = clk_get_parent_by_index(dpll_clk, 0);
	ref_rate = clk_get_rate(clk_ref);

	clk_bypass = clk_get_parent_by_index(dpll_clk, 1);
	bypass_rate = clk_get_rate(clk_bypass);

Currently the semantics around this call are weird. It seems like it
would create a new struct clk pointer but it does not. So don't call
clk_put on clk_ref and clk_bypass yet. That might change in the future
as we iron out this brave new world that we all live in. Probably best
to leave a FIXME in there.

Stephen & Tomeu, let me know if I got any of that wrong.

The plan is to make clk_get_parent_by_index() return a clk_hw pointer
instead of a clk pointer (probably with a new
clk_get_parent_hw_by_index() API). Then drivers that are clk providers
can deal in struct clk_hw and clk consumers can deal in struct clk,
nicely splitting the API between consumers and providers on the
structures they use to interact with the framework.

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