clk: at91: clk-generated: remove useless divisor loop

The driver requests the current clk rate of each of its parent clocks to
decide whether a clock rate is suitable or not. It does not request
determine_rate from a parent clock which could request a rate change in
parent clock (i.e. there is no parent rate propagation).

We know the rate we want (passed along req argument of the function) and
the parent clock rate, thus we know the closest rounded divisor, we
don't need to iterate over the available divisors to find the best one
for a given clock.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
index f0b7ae904ce2c991d8a5f998734a77235de194ee..ef4b4e03de04f1a71b0bd99625818c074df415b2 100644 (file)
--- a/drivers/clk/at91/clk-generated.c
+++ b/drivers/clk/at91/clk-generated.c
@@ -124,19 +124,18 @@ static int clk_generated_determine_rate(struct clk_hw *hw,
                    (gck->range.max && min_rate > gck->range.max))
                        continue;
 
-               for (div = 1; div < GENERATED_MAX_DIV + 2; div++) {
-                       tmp_rate = DIV_ROUND_CLOSEST(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;
-                       }
-
-                       if (!best_diff || tmp_rate < req->rate)
-                               break;
+               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) {
+                       best_rate = tmp_rate;
+                       best_diff = tmp_diff;
+                       req->best_parent_rate = parent_rate;
+                       req->best_parent_hw = parent;
                }
 
                if (!best_diff)