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			6.0 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			240 lines
		
	
	
		
			6.0 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
From ee28648cb2b4d4ab5c2eb8199ea86675fe19016b Mon Sep 17 00:00:00 2001
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From: Maxime Ripard <maxime.ripard@free-electrons.com>
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Date: Thu, 29 Sep 2016 22:53:12 +0200
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Subject: clk: sunxi-ng: Remove the use of rational computations
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While the rational library works great, it doesn't really allow us to add
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more constraints, like the minimum.
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Remove that in order to be able to deal with the constraints we'll need.
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Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
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Acked-by: Chen-Yu Tsai <wens@csie.org>
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---
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 drivers/clk/sunxi-ng/Kconfig    |  3 ---
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 drivers/clk/sunxi-ng/ccu_nkm.c  | 31 ++++++++++++-----------
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 drivers/clk/sunxi-ng/ccu_nkmp.c | 37 ++++++++++++++--------------
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 drivers/clk/sunxi-ng/ccu_nm.c   | 54 +++++++++++++++++++++++++++++++----------
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 4 files changed, 74 insertions(+), 51 deletions(-)
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--- a/drivers/clk/sunxi-ng/Kconfig
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+++ b/drivers/clk/sunxi-ng/Kconfig
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@@ -36,17 +36,14 @@ config SUNXI_CCU_NK
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 config SUNXI_CCU_NKM
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 	bool
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-	select RATIONAL
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 	select SUNXI_CCU_GATE
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 config SUNXI_CCU_NKMP
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 	bool
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-	select RATIONAL
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 	select SUNXI_CCU_GATE
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 config SUNXI_CCU_NM
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 	bool
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-	select RATIONAL
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 	select SUNXI_CCU_FRAC
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 	select SUNXI_CCU_GATE
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--- a/drivers/clk/sunxi-ng/ccu_nkm.c
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+++ b/drivers/clk/sunxi-ng/ccu_nkm.c
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@@ -9,7 +9,6 @@
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  */
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 #include <linux/clk-provider.h>
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-#include <linux/rational.h>
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 #include "ccu_gate.h"
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 #include "ccu_nkm.h"
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@@ -28,21 +27,21 @@ static void ccu_nkm_find_best(unsigned l
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 	unsigned long _n, _k, _m;
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 	for (_k = 1; _k <= nkm->max_k; _k++) {
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-		unsigned long tmp_rate;
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-
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-		rational_best_approximation(rate / _k, parent,
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-					    nkm->max_n, nkm->max_m, &_n, &_m);
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-
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-		tmp_rate = parent * _n * _k / _m;
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-
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-		if (tmp_rate > rate)
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-			continue;
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-
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-		if ((rate - tmp_rate) < (rate - best_rate)) {
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-			best_rate = tmp_rate;
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-			best_n = _n;
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-			best_k = _k;
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-			best_m = _m;
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+		for (_n = 1; _n <= nkm->max_n; _n++) {
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+			for (_m = 1; _n <= nkm->max_m; _m++) {
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+				unsigned long tmp_rate;
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+
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+				tmp_rate = parent * _n * _k / _m;
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+
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+				if (tmp_rate > rate)
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+					continue;
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+				if ((rate - tmp_rate) < (rate - best_rate)) {
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+					best_rate = tmp_rate;
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+					best_n = _n;
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+					best_k = _k;
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+					best_m = _m;
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+				}
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+			}
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 		}
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 	}
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--- a/drivers/clk/sunxi-ng/ccu_nkmp.c
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+++ b/drivers/clk/sunxi-ng/ccu_nkmp.c
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@@ -9,7 +9,6 @@
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  */
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 #include <linux/clk-provider.h>
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-#include <linux/rational.h>
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 #include "ccu_gate.h"
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 #include "ccu_nkmp.h"
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@@ -29,24 +28,24 @@ static void ccu_nkmp_find_best(unsigned
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 	unsigned long _n, _k, _m, _p;
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 	for (_k = 1; _k <= nkmp->max_k; _k++) {
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-		for (_p = 1; _p <= nkmp->max_p; _p <<= 1) {
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-			unsigned long tmp_rate;
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-
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-			rational_best_approximation(rate / _k, parent / _p,
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-						    nkmp->max_n, nkmp->max_m,
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-						    &_n, &_m);
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-
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-			tmp_rate = parent * _n * _k / (_m * _p);
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-
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-			if (tmp_rate > rate)
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-				continue;
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-
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-			if ((rate - tmp_rate) < (rate - best_rate)) {
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-				best_rate = tmp_rate;
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-				best_n = _n;
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-				best_k = _k;
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-				best_m = _m;
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-				best_p = _p;
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+		for (_n = 1; _n <= nkmp->max_n; _n++) {
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+			for (_m = 1; _n <= nkmp->max_m; _m++) {
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+				for (_p = 1; _p <= nkmp->max_p; _p <<= 1) {
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+					unsigned long tmp_rate;
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+
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+					tmp_rate = parent * _n * _k / (_m * _p);
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+
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+					if (tmp_rate > rate)
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+						continue;
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+
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+					if ((rate - tmp_rate) < (rate - best_rate)) {
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+						best_rate = tmp_rate;
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+						best_n = _n;
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+						best_k = _k;
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+						best_m = _m;
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+						best_p = _p;
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+					}
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+				}
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 			}
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 		}
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 	}
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--- a/drivers/clk/sunxi-ng/ccu_nm.c
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+++ b/drivers/clk/sunxi-ng/ccu_nm.c
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@@ -9,12 +9,42 @@
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  */
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 #include <linux/clk-provider.h>
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-#include <linux/rational.h>
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 #include "ccu_frac.h"
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 #include "ccu_gate.h"
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 #include "ccu_nm.h"
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+struct _ccu_nm {
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+	unsigned long	n, max_n;
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+	unsigned long	m, max_m;
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+};
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+
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+static void ccu_nm_find_best(unsigned long parent, unsigned long rate,
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+			     struct _ccu_nm *nm)
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+{
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+	unsigned long best_rate = 0;
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+	unsigned long best_n = 0, best_m = 0;
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+	unsigned long _n, _m;
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+
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+	for (_n = 1; _n <= nm->max_n; _n++) {
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+		for (_m = 1; _n <= nm->max_m; _m++) {
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+			unsigned long tmp_rate = parent * _n  / _m;
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+
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+			if (tmp_rate > rate)
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+				continue;
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+
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+			if ((rate - tmp_rate) < (rate - best_rate)) {
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+				best_rate = tmp_rate;
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+				best_n = _n;
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+				best_m = _m;
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+			}
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+		}
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+	}
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+
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+	nm->n = best_n;
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+	nm->m = best_m;
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+}
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+
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 static void ccu_nm_disable(struct clk_hw *hw)
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 {
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 	struct ccu_nm *nm = hw_to_ccu_nm(hw);
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@@ -61,24 +91,22 @@ static long ccu_nm_round_rate(struct clk
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 			      unsigned long *parent_rate)
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 {
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 	struct ccu_nm *nm = hw_to_ccu_nm(hw);
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-	unsigned long max_n, max_m;
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-	unsigned long n, m;
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+	struct _ccu_nm _nm;
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-	max_n = 1 << nm->n.width;
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-	max_m = nm->m.max ?: 1 << nm->m.width;
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+	_nm.max_n = 1 << nm->n.width;
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+	_nm.max_m = nm->m.max ?: 1 << nm->m.width;
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-	rational_best_approximation(rate, *parent_rate, max_n, max_m, &n, &m);
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+	ccu_nm_find_best(*parent_rate, rate, &_nm);
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-	return *parent_rate * n / m;
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+	return *parent_rate * _nm.n / _nm.m;
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 }
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 static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate,
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 			   unsigned long parent_rate)
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 {
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 	struct ccu_nm *nm = hw_to_ccu_nm(hw);
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+	struct _ccu_nm _nm;
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 	unsigned long flags;
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-	unsigned long max_n, max_m;
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-	unsigned long n, m;
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 	u32 reg;
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 	if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate))
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@@ -86,10 +114,10 @@ static int ccu_nm_set_rate(struct clk_hw
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 	else
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 		ccu_frac_helper_disable(&nm->common, &nm->frac);
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-	max_n = 1 << nm->n.width;
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-	max_m = nm->m.max ?: 1 << nm->m.width;
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+	_nm.max_n = 1 << nm->n.width;
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+	_nm.max_m = nm->m.max ?: 1 << nm->m.width;
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-	rational_best_approximation(rate, parent_rate, max_n, max_m, &n, &m);
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+	ccu_nm_find_best(parent_rate, rate, &_nm);
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 	spin_lock_irqsave(nm->common.lock, flags);
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@@ -97,7 +125,7 @@ static int ccu_nm_set_rate(struct clk_hw
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 	reg &= ~GENMASK(nm->n.width + nm->n.shift - 1, nm->n.shift);
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 	reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift);
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-	writel(reg | ((m - 1) << nm->m.shift) | ((n - 1) << nm->n.shift),
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+	writel(reg | ((_nm.m - 1) << nm->m.shift) | ((_nm.n - 1) << nm->n.shift),
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 	       nm->common.base + nm->common.reg);
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 	spin_unlock_irqrestore(nm->common.lock, flags);
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