[PATCH v6 10/12] media: ov5640: Make the FPS clamping / rounding more extendable

[Maxime Ripard]

The current code uses an algorithm to clamp the FPS values and round them
to the closest supported one that isn't really allows to be extended to
more than two values.

Rework it a bit to make it much easier to extend the amount of FPS options
we support.

Signed-off-by: Maxime Ripard <maxime.rip...@bootlin.com>
Tested-by: Adam Ford <aford...@gmail.com> #imx6dq
---
 drivers/media/i2c/ov5640.c | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
index 6cdf5ee0e4fa..93fa072135ad 100644
--- a/drivers/media/i2c/ov5640.c
+++ b/drivers/media/i2c/ov5640.c
@@ -2053,7 +2053,8 @@ static int ov5640_try_frame_interval(struct ov5640_dev 
*sensor,
 {
        const struct ov5640_mode_info *mode;
        enum ov5640_frame_rate rate = OV5640_30_FPS;
-       u32 minfps, maxfps, fps;
+       int minfps, maxfps, best_fps, fps;
+       int i;
 
        minfps = ov5640_framerates[OV5640_15_FPS];
        maxfps = ov5640_framerates[OV5640_30_FPS];
@@ -2064,19 +2065,21 @@ static int ov5640_try_frame_interval(struct ov5640_dev 
*sensor,
                return OV5640_30_FPS;
        }
 
-       fps = DIV_ROUND_CLOSEST(fi->denominator, fi->numerator);
+       fps = clamp_val(DIV_ROUND_CLOSEST(fi->denominator, fi->numerator),
+                       minfps, maxfps);
 
-       fi->numerator = 1;
-       if (fps > maxfps)
-               fi->denominator = maxfps;
-       else if (fps < minfps)
-               fi->denominator = minfps;
-       else if (2 * fps >= 2 * minfps + (maxfps - minfps))
-               fi->denominator = maxfps;
-       else
-               fi->denominator = minfps;
+       best_fps = minfps;
+       for (i = 0; i < ARRAY_SIZE(ov5640_framerates); i++) {
+               int curr_fps = ov5640_framerates[i];
 
-       rate = (fi->denominator == minfps) ? OV5640_15_FPS : OV5640_30_FPS;
+               if (abs(curr_fps - fps) < abs(best_fps - fps)) {
+                       best_fps = curr_fps;
+                       rate = i;
+               }
+       }
+
+       fi->numerator = 1;
+       fi->denominator = best_fps;
 
        mode = ov5640_find_mode(sensor, rate, width, height, false);
        return mode ? rate : -EINVAL;
-- 
git-series 0.9.1