power: supply: axp20x_usb_power: Use regmap fields for VBUS monitor feature

Use regmap fields to describe the VBUS valid bit and VBUS monitor
enable bit. This allows the driver to easily support other chips,
eg. the AXP192, that have the VBUS valid bit in a different register.

Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

Author: Aidan MacDonald

drivers/power/supply/axp20x_usb_power.c

@@ -41,8 +41,6 @@
 #define AXP20X_ADC_EN1_VBUS_CURR	BIT(2)
 #define AXP20X_ADC_EN1_VBUS_VOLT	BIT(3)
 
-#define AXP20X_VBUS_MON_VBUS_VALID	BIT(3)
-
 #define AXP813_BC_EN		BIT(0)
 
 /*
@@ -58,11 +56,15 @@ struct axp_data {
 	enum axp20x_variants		axp20x_id;
 	const int			*curr_lim_table;
 	struct reg_field		curr_lim_fld;
+	struct reg_field		vbus_valid_bit;
+	struct reg_field		vbus_mon_bit;
 };
 
 struct axp20x_usb_power {
 	struct regmap *regmap;
 	struct regmap_field *curr_lim_fld;
+	struct regmap_field *vbus_valid_bit;
+	struct regmap_field *vbus_mon_bit;
 	struct power_supply *supply;
 	enum axp20x_variants axp20x_id;
 	const struct axp_data *axp_data;
@@ -206,16 +208,15 @@ static int axp20x_usb_power_get_property(struct power_supply *psy,
 
 		val->intval = POWER_SUPPLY_HEALTH_GOOD;
 
-		if (power->axp20x_id == AXP202_ID) {
-			ret = regmap_read(power->regmap,
-					  AXP20X_USB_OTG_STATUS, &v);
+		if (power->vbus_valid_bit) {
+			ret = regmap_field_read(power->vbus_valid_bit, &v);
 			if (ret)
 				return ret;
 
-			if (!(v & AXP20X_USB_STATUS_VBUS_VALID))
-				val->intval =
-					POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+			if (v == 0)
+				val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
 		}
+
 		break;
 	case POWER_SUPPLY_PROP_PRESENT:
 		val->intval = !!(input & AXP20X_PWR_STATUS_VBUS_PRESENT);
@@ -403,6 +404,8 @@ static const struct axp_data axp202_data = {
 	.axp20x_id	= AXP202_ID,
 	.curr_lim_table = axp20x_usb_curr_lim_table,
 	.curr_lim_fld   = REG_FIELD(AXP20X_VBUS_IPSOUT_MGMT, 0, 1),
+	.vbus_valid_bit = REG_FIELD(AXP20X_USB_OTG_STATUS, 2, 2),
+	.vbus_mon_bit   = REG_FIELD(AXP20X_VBUS_MON, 3, 3),
 };
 
 static const struct axp_data axp221_data = {
@@ -501,6 +504,26 @@ static int configure_adc_registers(struct axp20x_usb_power *power)
 				  AXP20X_ADC_EN1_VBUS_VOLT);
 }
 
+static int axp20x_regmap_field_alloc_optional(struct device *dev,
+					      struct regmap *regmap,
+					      struct reg_field fdesc,
+					      struct regmap_field **fieldp)
+{
+	struct regmap_field *field;
+
+	if (fdesc.reg == 0) {
+		*fieldp = NULL;
+		return 0;
+	}
+
+	field = devm_regmap_field_alloc(dev, regmap, fdesc);
+	if (IS_ERR(field))
+		return PTR_ERR(field);
+
+	*fieldp = field;
+	return 0;
+}
+
 static int axp20x_usb_power_probe(struct platform_device *pdev)
 {
 	struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
@@ -537,16 +560,26 @@ static int axp20x_usb_power_probe(struct platform_device *pdev)
 	if (IS_ERR(power->curr_lim_fld))
 		return PTR_ERR(power->curr_lim_fld);
 
+	ret = axp20x_regmap_field_alloc_optional(&pdev->dev, power->regmap,
+						 axp_data->vbus_valid_bit,
+						 &power->vbus_valid_bit);
+	if (ret)
+		return ret;
+
+	ret = axp20x_regmap_field_alloc_optional(&pdev->dev, power->regmap,
+						 axp_data->vbus_mon_bit,
+						 &power->vbus_mon_bit);
+	if (ret)
+		return ret;
+
 	ret = devm_delayed_work_autocancel(&pdev->dev, &power->vbus_detect,
 					   axp20x_usb_power_poll_vbus);
 	if (ret)
 		return ret;
 
-	if (power->axp20x_id == AXP202_ID) {
+	if (power->vbus_mon_bit) {
 		/* Enable vbus valid checking */
-		ret = regmap_update_bits(power->regmap, AXP20X_VBUS_MON,
-					 AXP20X_VBUS_MON_VBUS_VALID,
-					 AXP20X_VBUS_MON_VBUS_VALID);
+		ret = regmap_field_write(power->vbus_mon_bit, 1);
 		if (ret)
 			return ret;