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

Quentin Schulz
2017-07-04T11:59:23Z

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>
---
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