1 files changed, 45 insertions, 13 deletions

diff --git a/drivers/clk/sunxi-ng/ccu_nm.c b/drivers/clk/sunxi-ng/ccu_nm.c
index b61bdd8c7a7f..c9f3b6c982f0 100644
--- a/drivers/clk/sunxi-ng/ccu_nm.c
+++ b/drivers/clk/sunxi-ng/ccu_nm.c
@@ -9,12 +9,42 @@
  */
 
 #include <linux/clk-provider.h>
-#include <linux/rational.h>
 
 #include "ccu_frac.h"
 #include "ccu_gate.h"
 #include "ccu_nm.h"
 
+struct _ccu_nm {
+	unsigned long	n, min_n, max_n;
+	unsigned long	m, min_m, max_m;
+};
+
+static void ccu_nm_find_best(unsigned long parent, unsigned long rate,
+			     struct _ccu_nm *nm)
+{
+	unsigned long best_rate = 0;
+	unsigned long best_n = 0, best_m = 0;
+	unsigned long _n, _m;
+
+	for (_n = nm->min_n; _n <= nm->max_n; _n++) {
+		for (_m = nm->min_m; _m <= nm->max_m; _m++) {
+			unsigned long tmp_rate = parent * _n  / _m;
+
+			if (tmp_rate > rate)
+				continue;
+
+			if ((rate - tmp_rate) < (rate - best_rate)) {
+				best_rate = tmp_rate;
+				best_n = _n;
+				best_m = _m;
+			}
+		}
+	}
+
+	nm->n = best_n;
+	nm->m = best_m;
+}
+
 static void ccu_nm_disable(struct clk_hw *hw)
 {
 	struct ccu_nm *nm = hw_to_ccu_nm(hw);
@@ -61,24 +91,24 @@ static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate,
 			      unsigned long *parent_rate)
 {
 	struct ccu_nm *nm = hw_to_ccu_nm(hw);
-	unsigned long max_n, max_m;
-	unsigned long n, m;
+	struct _ccu_nm _nm;
 
-	max_n = 1 << nm->n.width;
-	max_m = nm->m.max ?: 1 << nm->m.width;
+	_nm.min_n = nm->n.min;
+	_nm.max_n = 1 << nm->n.width;
+	_nm.min_m = 1;
+	_nm.max_m = nm->m.max ?: 1 << nm->m.width;
 
-	rational_best_approximation(rate, *parent_rate, max_n, max_m, &n, &m);
+	ccu_nm_find_best(*parent_rate, rate, &_nm);
 
-	return *parent_rate * n / m;
+	return *parent_rate * _nm.n / _nm.m;
 }
 
 static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate,
 			   unsigned long parent_rate)
 {
 	struct ccu_nm *nm = hw_to_ccu_nm(hw);
+	struct _ccu_nm _nm;
 	unsigned long flags;
-	unsigned long max_n, max_m;
-	unsigned long n, m;
 	u32 reg;
 
 	if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate))
@@ -86,10 +116,12 @@ static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate,
 	else
 		ccu_frac_helper_disable(&nm->common, &nm->frac);
 
-	max_n = 1 << nm->n.width;
-	max_m = nm->m.max ?: 1 << nm->m.width;
+	_nm.min_n = 1;
+	_nm.max_n = 1 << nm->n.width;
+	_nm.min_m = 1;
+	_nm.max_m = nm->m.max ?: 1 << nm->m.width;
 
-	rational_best_approximation(rate, parent_rate, max_n, max_m, &n, &m);
+	ccu_nm_find_best(parent_rate, rate, &_nm);
 
 	spin_lock_irqsave(nm->common.lock, flags);
 
@@ -97,7 +129,7 @@ static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate,
 	reg &= ~GENMASK(nm->n.width + nm->n.shift - 1, nm->n.shift);
 	reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift);
 
-	writel(reg | ((m - 1) << nm->m.shift) | ((n - 1) << nm->n.shift),
+	writel(reg | ((_nm.m - 1) << nm->m.shift) | ((_nm.n - 1) << nm->n.shift),
 	       nm->common.base + nm->common.reg);
 
 	spin_unlock_irqrestore(nm->common.lock, flags);