regulator: max8997: Remove n_bits from struct voltage_map_desc

The n_bits is only used in max8997_get_voltage_proper_val to check the valid
range for variable i.

Current code already ensures min_vol never greater than desc->max,
which means the variable i always in the valid range:
0 .. (desc->max - desc->min)/desc->step.

Thus we can remove the checking (i >= (1 << desc->n_bits) and then remove
n_bits from struct voltage_map_desc.

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

drivers/regulator/max8997.c

@@ -68,29 +68,28 @@ struct voltage_map_desc {
 	int min;
 	int max;
 	int step;
-	unsigned int n_bits;
 };
 
 /* Voltage maps in mV */
 static const struct voltage_map_desc ldo_voltage_map_desc = {
-	.min = 800,	.max = 3950,	.step = 50,	.n_bits = 6,
+	.min = 800,	.max = 3950,	.step = 50,
 }; /* LDO1 ~ 18, 21 all */
 
 static const struct voltage_map_desc buck1245_voltage_map_desc = {
-	.min = 650,	.max = 2225,	.step = 25,	.n_bits = 6,
+	.min = 650,	.max = 2225,	.step = 25,
 }; /* Buck1, 2, 4, 5 */
 
 static const struct voltage_map_desc buck37_voltage_map_desc = {
-	.min = 750,	.max = 3900,	.step = 50,	.n_bits = 6,
+	.min = 750,	.max = 3900,	.step = 50,
 }; /* Buck3, 7 */
 
 /* current map in mA */
 static const struct voltage_map_desc charger_current_map_desc = {
-	.min = 200,	.max = 950,	.step = 50,	.n_bits = 4,
+	.min = 200,	.max = 950,	.step = 50,
 };
 
 static const struct voltage_map_desc topoff_current_map_desc = {
-	.min = 50,	.max = 200,	.step = 10,	.n_bits = 4,
+	.min = 50,	.max = 200,	.step = 10,
 };
 
 static const struct voltage_map_desc *reg_voltage_map[] = {
@@ -431,9 +430,6 @@ static inline int max8997_get_voltage_proper_val(
 	if (desc->min + desc->step * i > max_vol)
 		return -EINVAL;
 
-	if (i >= (1 << desc->n_bits))
-		return -EINVAL;
-
 	return i;
 }