regulator: max8998: Use simple equation to get selector

It's more efficient to get the best selector by simple equation.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 10 insertions, 9 deletions

diff --git a/drivers/regulator/max8998.c b/drivers/regulator/max8998.c
index 74b0b0c94120..7e831a94bf84 100644
--- a/drivers/regulator/max8998.c
+++ b/drivers/regulator/max8998.c
@@ -306,8 +306,7 @@ static int max8998_set_voltage_ldo(struct regulator_dev *rdev,
         int min_vol = min_uV / 1000, max_vol = max_uV / 1000;
         const struct voltage_map_desc *desc;
         int ldo = rdev_get_id(rdev);
-        int reg, shift = 0, mask, ret;
-        int i = 0;
+        int reg, shift = 0, mask, ret, i;
 
         if (ldo >= ARRAY_SIZE(ldo_voltage_map))
                 return -EINVAL;
@@ -319,9 +318,10 @@ static int max8998_set_voltage_ldo(struct regulator_dev *rdev,
         if (max_vol < desc->min || min_vol > desc->max)
                 return -EINVAL;
 
-        while (desc->min + desc->step*i < min_vol &&
-               desc->min + desc->step*i < desc->max)
-                i++;
+        if (min_vol < desc->min)
+                min_vol = desc->min;
+
+        i = DIV_ROUND_UP(min_vol - desc->min, desc->step);
 
         if (desc->min + desc->step*i > max_vol)
                 return -EINVAL;
@@ -359,7 +359,7 @@ static int max8998_set_voltage_buck(struct regulator_dev *rdev,
         const struct voltage_map_desc *desc;
         int buck = rdev_get_id(rdev);
         int reg, shift = 0, mask, ret;
-        int difference = 0, i = 0, j = 0, previous_vol = 0;
+        int difference = 0, i, j = 0, previous_vol = 0;
         u8 val = 0;
         static u8 buck1_last_val;
 
@@ -374,9 +374,10 @@ static int max8998_set_voltage_buck(struct regulator_dev *rdev,
         if (max_vol < desc->min || min_vol > desc->max)
                 return -EINVAL;
 
-        while (desc->min + desc->step*i < min_vol &&
-               desc->min + desc->step*i < desc->max)
-                i++;
+        if (min_vol < desc->min)
+                min_vol = desc->min;
+
+        i = DIV_ROUND_UP(min_vol - desc->min, desc->step);
 
         if (desc->min + desc->step*i > max_vol)
                 return -EINVAL;