clk: sunxi-ng: Remove the use of rational computations

While the rational library works great, it doesn't really allow us to add
more constraints, like the minimum.

Remove that in order to be able to deal with the constraints we'll need.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>

drivers/clk/sunxi-ng/ccu_nkmp.c

@@ -9,7 +9,6 @@
  */
 
 #include <linux/clk-provider.h>
-#include <linux/rational.h>
 
 #include "ccu_gate.h"
 #include "ccu_nkmp.h"
@@ -29,24 +28,24 @@ static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate,
 	unsigned long _n, _k, _m, _p;
 
 	for (_k = 1; _k <= nkmp->max_k; _k++) {
-		for (_p = 1; _p <= nkmp->max_p; _p <<= 1) {
-			unsigned long tmp_rate;
+		for (_n = 1; _n <= nkmp->max_n; _n++) {
+			for (_m = 1; _n <= nkmp->max_m; _m++) {
+				for (_p = 1; _p <= nkmp->max_p; _p <<= 1) {
+					unsigned long tmp_rate;
 
-			rational_best_approximation(rate / _k, parent / _p,
-						    nkmp->max_n, nkmp->max_m,
-						    &_n, &_m);
+					tmp_rate = parent * _n * _k / (_m * _p);
 
-			tmp_rate = parent * _n * _k / (_m * _p);
+					if (tmp_rate > rate)
+						continue;
 
-			if (tmp_rate > rate)
-				continue;
-
-			if ((rate - tmp_rate) < (rate - best_rate)) {
-				best_rate = tmp_rate;
-				best_n = _n;
-				best_k = _k;
-				best_m = _m;
-				best_p = _p;
+					if ((rate - tmp_rate) < (rate - best_rate)) {
+						best_rate = tmp_rate;
+						best_n = _n;
+						best_k = _k;
+						best_m = _m;
+						best_p = _p;
+					}
+				}
 			}
 		}
 	}