power: supply: rn5t618: Add voltage_now property

Read voltage_now via IIO and provide the property.
Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Reported-by: kernel test robot <lkp@intel.com> # missing depends on IIO
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/supply/Kconfig

@@ -792,6 +792,8 @@ config CHARGER_WILCO
 config RN5T618_POWER
 	tristate "RN5T618 charger/fuel gauge support"
 	depends on MFD_RN5T618
+	depends on RN5T618_ADC
+	depends on IIO
 	help
 	  Say Y here to have support for RN5T618 PMIC family fuel gauge and charger.
 	  This driver can also be built as a module. If so, the module will be

drivers/power/supply/rn5t618_power.c

@@ -9,10 +9,12 @@
 #include <linux/device.h>
 #include <linux/bitops.h>
 #include <linux/errno.h>
+#include <linux/iio/consumer.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/mfd/rn5t618.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/power_supply.h>
 #include <linux/regmap.h>
@@ -64,6 +66,8 @@ struct rn5t618_power_info {
 	struct power_supply *battery;
 	struct power_supply *usb;
 	struct power_supply *adp;
+	struct iio_channel *channel_vusb;
+	struct iio_channel *channel_vadp;
 	int irq;
 };
 
@@ -77,6 +81,7 @@ static enum power_supply_usb_type rn5t618_usb_types[] = {
 static enum power_supply_property rn5t618_usb_props[] = {
 	/* input current limit is not very accurate */
 	POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
 	POWER_SUPPLY_PROP_STATUS,
 	POWER_SUPPLY_PROP_USB_TYPE,
 	POWER_SUPPLY_PROP_ONLINE,
@@ -85,6 +90,7 @@ static enum power_supply_property rn5t618_usb_props[] = {
 static enum power_supply_property rn5t618_adp_props[] = {
 	/* input current limit is not very accurate */
 	POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
 	POWER_SUPPLY_PROP_STATUS,
 	POWER_SUPPLY_PROP_ONLINE,
 };
@@ -463,6 +469,15 @@ static int rn5t618_adp_get_property(struct power_supply *psy,
 			return ret;
 
 		val->intval = FROM_CUR_REG(regval);
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		if (!info->channel_vadp)
+			return -ENODATA;
+
+		ret = iio_read_channel_processed_scale(info->channel_vadp, &val->intval, 1000);
+		if (ret < 0)
+			return ret;
+
 		break;
 	default:
 		return -EINVAL;
@@ -588,6 +603,15 @@ static int rn5t618_usb_get_property(struct power_supply *psy,
 
 			val->intval = FROM_CUR_REG(regval);
 		}
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		if (!info->channel_vusb)
+			return -ENODATA;
+
+		ret = iio_read_channel_processed_scale(info->channel_vusb, &val->intval, 1000);
+		if (ret < 0)
+			return ret;
+
 		break;
 	default:
 		return -EINVAL;
@@ -711,6 +735,20 @@ static int rn5t618_power_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, info);
 
+	info->channel_vusb = devm_iio_channel_get(&pdev->dev, "vusb");
+	if (IS_ERR(info->channel_vusb)) {
+		if (PTR_ERR(info->channel_vusb) == -ENODEV)
+			return -EPROBE_DEFER;
+		return PTR_ERR(info->channel_vusb);
+	}
+
+	info->channel_vadp = devm_iio_channel_get(&pdev->dev, "vadp");
+	if (IS_ERR(info->channel_vadp)) {
+		if (PTR_ERR(info->channel_vadp) == -ENODEV)
+			return -EPROBE_DEFER;
+		return PTR_ERR(info->channel_vadp);
+	}
+
 	ret = regmap_read(info->rn5t618->regmap, RN5T618_CONTROL, &v);
 	if (ret)
 		return ret;