Commit 8a8f4bf0 authored by Quentin Schulz's avatar Quentin Schulz Committed by Stephen Boyd
Browse files

clk: at91: clk-generated: create function to find best_diff 



The way to find the best_diff and do the appropriate process afterwards
can be re-used.

This patch prepares the driver for an upcoming patch that will allow
clk_generated to determine the rate of the audio_pll.

Signed-off-by: default avatarQuentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: default avatarNicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
parent 0865805d

drivers/clk/at91/clk-generated.c

+27 −14
Original line number Original line Diff line number Diff line
@@ -99,15 +99,36 @@ clk_generated_recalc_rate(struct clk_hw *hw, 
	return DIV_ROUND_CLOSEST(parent_rate, gck->gckdiv + 1);

	return DIV_ROUND_CLOSEST(parent_rate, gck->gckdiv + 1);

}

}





static void clk_generated_best_diff(struct clk_rate_request *req,

				    struct clk_hw *parent,

				    unsigned long parent_rate, u32 div,

				    int *best_diff, long *best_rate)

{

	unsigned long tmp_rate;

	int tmp_diff;



	if (!div)

		tmp_rate = parent_rate;

	else

		tmp_rate = parent_rate / div;

	tmp_diff = abs(req->rate - tmp_rate);



	if (*best_diff < 0 || *best_diff > tmp_diff) {

		*best_rate = tmp_rate;

		*best_diff = tmp_diff;

		req->best_parent_rate = parent_rate;

		req->best_parent_hw = parent;

	}

}



static int clk_generated_determine_rate(struct clk_hw *hw,

static int clk_generated_determine_rate(struct clk_hw *hw,

					struct clk_rate_request *req)

					struct clk_rate_request *req)

{

{

	struct clk_generated *gck = to_clk_generated(hw);

	struct clk_generated *gck = to_clk_generated(hw);

	struct clk_hw *parent = NULL;

	struct clk_hw *parent = NULL;

	long best_rate = -EINVAL;

	long best_rate = -EINVAL;

	unsigned long tmp_rate, min_rate;

	unsigned long min_rate;

	int best_diff = -1;

	int best_diff = -1;

	int tmp_diff;

	int i;

	int i;





	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {

	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
@@ -125,18 +146,10 @@ static int clk_generated_determine_rate(struct clk_hw *hw, 
			continue;

			continue;





		div = DIV_ROUND_CLOSEST(parent_rate, req->rate);

		div = DIV_ROUND_CLOSEST(parent_rate, req->rate);

		if (!div)

			tmp_rate = parent_rate;

		else

			tmp_rate = parent_rate / div;

		tmp_diff = abs(req->rate - tmp_rate);





		if (best_diff < 0 || best_diff > tmp_diff) {

		clk_generated_best_diff(req, parent, parent_rate, div,

			best_rate = tmp_rate;

					&best_diff, &best_rate);

			best_diff = tmp_diff;



			req->best_parent_rate = parent_rate;

			req->best_parent_hw = parent;

		}





		if (!best_diff)

		if (!best_diff)

			break;

			break;

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