pmic:max8997: Function for calculating LDO internal register value

Function for calculating LDO internal register value from passed micro
Volt.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Stefano Babic <sbabic@denx.de>

drivers/power/pmic/pmic_max8997.c

@@ -27,6 +27,22 @@
 #include <i2c.h>
 #include <errno.h>
 
+unsigned char max8997_reg_ldo(int uV)
+{
+	unsigned char ret;
+	if (uV <= 800000)
+		return 0;
+	if (uV >= 3950000)
+		return MAX8997_LDO_MAX_VAL;
+	ret = (uV - 800000) / 50000;
+	if (ret > MAX8997_LDO_MAX_VAL) {
+		printf("MAX8997 LDO SETTING ERROR (%duV) -> %u\n", uV, ret);
+		ret = MAX8997_LDO_MAX_VAL;
+	}
+
+	return ret;
+}
+
 int pmic_init(unsigned char bus)
 {
 	static const char name[] = "MAX8997_PMIC";

include/power/max8997_pmic.h

@@ -200,4 +200,6 @@ enum {
 	EN_LDO = (0x3 << 6),
 };
 
+#define MAX8997_LDO_MAX_VAL 0x3F
+unsigned char max8997_reg_ldo(int uV);
 #endif /* __MAX8997_PMIC_H_ */