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Commit 0f6cc2b8 authored by Jerome Brunet's avatar Jerome Brunet Committed by Michael Turquette
Browse files

clk: rework calls to round and determine rate callbacks 



Rework the way the callbacks round_rate() and determine_rate() are called.
The goal is to do this at a single point and make it easier to add
conditions before calling them.

Because of this factorization, rate returned by determine_rate() is also
checked against the min and max rate values

This rework is done to ease the integration of "protected" clock
functionality.

Acked-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Tested-by: default avatarQuentin Schulz <quentin.schulz@free-electrons.com>
Tested-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: default avatarMichael Turquette <mturquette@baylibre.com>
Signed-off-by: default avatarJerome Brunet <jbrunet@baylibre.com>
Signed-off-by: default avatarMichael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-5-jbrunet@baylibre.com
parent 9e4d04ad

drivers/clk/clk.c

+52 −30
Original line number Diff line number Diff line
@@ -905,10 +905,9 @@ static int clk_disable_unused(void) 
}

late_initcall_sync(clk_disable_unused);



static int clk_core_round_rate_nolock(struct clk_core *core,

static int clk_core_determine_round_nolock(struct clk_core *core,

					   struct clk_rate_request *req)

{

	struct clk_core *parent;

	long rate;



	lockdep_assert_held(&prepare_lock);
@@ -916,15 +915,6 @@ static int clk_core_round_rate_nolock(struct clk_core *core, 
	if (!core)

		return 0;



	parent = core->parent;

	if (parent) {

		req->best_parent_hw = parent->hw;

		req->best_parent_rate = parent->rate;

	} else {

		req->best_parent_hw = NULL;

		req->best_parent_rate = 0;

	}



	if (core->ops->determine_rate) {

		return core->ops->determine_rate(core->hw, req);

	} else if (core->ops->round_rate) {
@@ -934,15 +924,58 @@ static int clk_core_round_rate_nolock(struct clk_core *core, 
			return rate;



		req->rate = rate;

	} else if (core->flags & CLK_SET_RATE_PARENT) {

		return clk_core_round_rate_nolock(parent, req);

	} else {

		req->rate = core->rate;

		return -EINVAL;

	}



	return 0;

}



static void clk_core_init_rate_req(struct clk_core * const core,

				   struct clk_rate_request *req)

{

	struct clk_core *parent;



	if (WARN_ON(!core || !req))

		return;



	parent = core->parent;

	if (parent) {

		req->best_parent_hw = parent->hw;

		req->best_parent_rate = parent->rate;

	} else {

		req->best_parent_hw = NULL;

		req->best_parent_rate = 0;

	}

}



static bool clk_core_can_round(struct clk_core * const core)

{

	if (core->ops->determine_rate || core->ops->round_rate)

		return true;



	return false;

}



static int clk_core_round_rate_nolock(struct clk_core *core,

				      struct clk_rate_request *req)

{

	lockdep_assert_held(&prepare_lock);



	if (!core)

		return 0;



	clk_core_init_rate_req(core, req);



	if (clk_core_can_round(core))

		return clk_core_determine_round_nolock(core, req);

	else if (core->flags & CLK_SET_RATE_PARENT)

		return clk_core_round_rate_nolock(core->parent, req);



	req->rate = core->rate;

	return 0;

}



/**

 * __clk_determine_rate - get the closest rate actually supported by a clock

 * @hw: determine the rate of this clock
@@ -1432,34 +1465,23 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *core, 
	clk_core_get_boundaries(core, &min_rate, &max_rate);



	/* find the closest rate and parent clk/rate */

	if (core->ops->determine_rate) {

	if (clk_core_can_round(core)) {

		struct clk_rate_request req;



		req.rate = rate;

		req.min_rate = min_rate;

		req.max_rate = max_rate;

		if (parent) {

			req.best_parent_hw = parent->hw;

			req.best_parent_rate = parent->rate;

		} else {

			req.best_parent_hw = NULL;

			req.best_parent_rate = 0;

		}



		ret = core->ops->determine_rate(core->hw, &req);

		clk_core_init_rate_req(core, &req);



		ret = clk_core_determine_round_nolock(core, &req);

		if (ret < 0)

			return NULL;



		best_parent_rate = req.best_parent_rate;

		new_rate = req.rate;

		parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;

	} else if (core->ops->round_rate) {

		ret = core->ops->round_rate(core->hw, rate,

					    &best_parent_rate);

		if (ret < 0)

			return NULL;



		new_rate = ret;

		if (new_rate < min_rate || new_rate > max_rate)

			return NULL;

	} else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {