[PATCH v2 5/9] clk: at91: clk-generated: create function to find best_diff

[Quentin Schulz]

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.sch...@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezil...@free-electrons.com>
---
 drivers/clk/at91/clk-generated.c | 41 ++++++++++++++++++++++++++--------------
 1 file changed, 27 insertions(+), 14 deletions(-)

diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
index dab7002937e6..6530a2e7e84d 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;
-- 
2.11.0