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: 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>

1 files changed, 27 insertions, 14 deletions

diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
index ef4b4e03de04..7260e498e059 100644
--- a/drivers/clk/at91/clk-generated.c
+++ b/drivers/clk/at91/clk-generated.c
@@ -99,15 +99,36 @@ clk_generated_recalc_rate(struct clk_hw *hw,
         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,
                                         struct clk_rate_request *req)
 {
         struct clk_generated *gck = to_clk_generated(hw);
         struct clk_hw *parent = NULL;
         long best_rate = -EINVAL;
-        unsigned long tmp_rate, min_rate;
+        unsigned long min_rate;
         int best_diff = -1;
-        int tmp_diff;
         int 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;
 
                 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;
-                }
+
+                clk_generated_best_diff(req, parent, parent_rate, div,
+                                        &best_diff, &best_rate);
+
 
                 if (!best_diff)
                         break;