The AXP209 has a few 'magisc-ish' values that are better served with

clear defines.

drivers/power/axp209.c

@@ -81,8 +81,7 @@ int axp_set_aldo2(unsigned int mvolt)
 	if (rc)
 		return rc;
 
-	/* LDO2 configuration is in upper 4 bits */
-	reg = (reg & 0x0f) | (cfg << 4);
+	reg |= AXP209_LDO24_LDO2_SET(reg, cfg);
 	rc = pmic_bus_write(AXP209_LDO24_VOLTAGE, reg);
 	if (rc)
 		return rc;
@@ -100,9 +99,9 @@ int axp_set_aldo3(unsigned int mvolt)
 					AXP209_OUTPUT_CTRL_LDO3);
 
 	if (mvolt == -1)
-		cfg = 0x80;	/* determined by LDO3IN pin */
+		cfg = AXP209_LDO3_VOLTAGE_FROM_LDO3IN;
 	else
-		cfg = axp209_mvolt_to_cfg(mvolt, 700, 3500, 25);
+		cfg = AXP209_LDO3_VOLTAGE_SET(axp209_mvolt_to_cfg(mvolt, 700, 3500, 25));
 
 	rc = pmic_bus_write(AXP209_LDO3_VOLTAGE, cfg);
 	if (rc)
@@ -131,8 +130,7 @@ int axp_set_aldo4(unsigned int mvolt)
 	if (rc)
 		return rc;
 
-	/* LDO4 configuration is in lower 4 bits */
-	reg = (reg & 0xf0) | (cfg << 0);
+	reg |= AXP209_LDO24_LDO4_SET(reg, cfg);
 	rc = pmic_bus_write(AXP209_LDO24_VOLTAGE, reg);
 	if (rc)
 		return rc;

include/axp209.h

@@ -34,6 +34,20 @@ enum axp209_reg {
 #define AXP209_OUTPUT_CTRL_DCDC2	BIT(4)
 #define AXP209_OUTPUT_CTRL_LDO3		BIT(6)
 
+#define AXP209_LDO24_LDO2_MASK		0xf0
+#define AXP209_LDO24_LDO4_MASK		0x0f
+#define AXP209_LDO24_LDO2_SET(reg, cfg)	\
+	(((reg) & ~AXP209_LDO24_LDO2_MASK) | \
+	(((cfg) << 4) & AXP209_LDO24_LDO2_MASK))
+#define AXP209_LDO24_LDO4_SET(reg, cfg)	\
+	(((reg) & ~AXP209_LDO24_LDO4_MASK) | \
+	(((cfg) << 0) & AXP209_LDO24_LDO4_MASK))
+
+
+#define AXP209_LDO3_VOLTAGE_FROM_LDO3IN	BIT(7)
+#define AXP209_LDO3_VOLTAGE_MASK	0x7f
+#define AXP209_LDO3_VOLTAGE_SET(x)	((x) & AXP209_LDO3_VOLTAGE_MASK)
+
 #define AXP209_IRQ5_PEK_UP		BIT(6)
 #define AXP209_IRQ5_PEK_DOWN		BIT(5)