regulator: as3711: Fix valid min_uV/max_UV checking in as3711_bound_check

Below equation means the "voltage" is the "smallest" voltage within specific range.

ret = DIV_ROUND_UP(min - bottom) / step;
voltage = ret * step + bottom;

If we do try 1 down when (voltage > max), new voltage is then less than min voltage. Which means the new voltage is not in the requested voltage range.

This patch also includes below cleanups:
- Use DIV_ROUND_UP
- rename variable 'ret' to 'sel' for better readability because as3711_sel_check returns the selector.

Signed-off-by Axel Lin <[email protected]>

---
 drivers/regulator/as3711-regulator.c |   23 ++++++++---------------
 1 file changed, 8 insertions(+), 15 deletions(-)

drivers/regulator/as3711-regulator.c +8 -15

index 5e813b9..2f1341d 100644
@@ -93,24 +93,17 @@ static int as3711_bound_check(struct regulator_dev *rdev,
 
 static int as3711_sel_check(int min, int max, int bottom, int step)
 {
-	int ret, voltage;
+	int sel, voltage;
 
 	/* Round up min, when dividing: keeps us within the range */
-	ret = (min - bottom + step - 1) / step;
-	voltage = ret * step + bottom;
+	sel = DIV_ROUND_UP(min - bottom, step);
+	voltage = sel * step + bottom;
 	pr_debug("%s(): select %d..%d in %d+N*%d: %d\n", __func__,
-	       min, max, bottom, step, ret);
-	if (voltage > max) {
-		/*
-		 * Try 1 down. It will take us below min, but as long we stay
-		 * above bottom, we're fine.
-		 */
-		ret--;
-		voltage = ret * step + bottom;
-		if (voltage < bottom)
-			return -EINVAL;
-	}
-	return ret;
+	       min, max, bottom, step, sel);
+	if (voltage > max)
+		return -EINVAL;
+
+	return sel;
 }
 
 static int as3711_map_voltage_sd(struct regulator_dev *rdev,

Signature · 1 line

1.7.9.5

Below cases are supposed to be valid:

min_uV == max_uV == info->max_uV
min_uV == max_uV == rdev->desc->min_uV

Don't return -EINVAL for above cases.

This patch also includes below cleanups:
- Use rdev_get_drvdata(rdev) instead of rdev->reg_data.
- Remove unnecessary WARN_ON, it looks pointless.

Signed-off-by Axel Lin <[email protected]>

---
 drivers/regulator/as3711-regulator.c |    9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

drivers/regulator/as3711-regulator.c +3 -6

index 81578bf..5e813b9 100644
@@ -69,17 +69,14 @@ static int as3711_list_voltage_dldo(struct regulator_dev *rdev,
 static int as3711_bound_check(struct regulator_dev *rdev,
 			      int *min_uV, int *max_uV)
 {
-	struct as3711_regulator_info *info = container_of(rdev->desc,
-					struct as3711_regulator_info, desc);
-	struct as3711_regulator *reg = rdev->reg_data;
-
-	WARN_ON(reg->reg_info != info);
+	struct as3711_regulator *reg = rdev_get_drvdata(rdev);
+	struct as3711_regulator_info *info = reg->reg_info;
 
 	dev_dbg(&rdev->dev, "%s(), %d, %d, %d\n", __func__,
 		*min_uV, rdev->desc->min_uV, info->max_uV);
 
 	if (*max_uV < *min_uV ||
-	    *min_uV >= info->max_uV || rdev->desc->min_uV >= *max_uV)
+	    *min_uV > info->max_uV || rdev->desc->min_uV > *max_uV)
 		return -EINVAL;
 
 	if (rdev->desc->n_voltages == 1)

Signature · 1 line

1.7.9.5

Below cases are supposed to be valid:

min_uV == max_uV == info->max_uV
min_uV == max_uV == rdev->desc->min_uV