lp8788-charger: Fix wrong ADC conversion

To get the battery voltage and temperature, IIO ADC functions are used.
LP8788 ADC driver provides RAW and SCALE channel information. This patch
fixes wrong ADC result.

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Reviewed-by Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>

drivers/power/lp8788-charger.c

@@ -235,25 +235,14 @@ static int lp8788_get_battery_present(struct lp8788_charger *pchg,
 	return 0;
 }
 
-static int lp8788_get_vbatt_adc(struct lp8788_charger *pchg,
-				unsigned int *result)
+static int lp8788_get_vbatt_adc(struct lp8788_charger *pchg, int *result)
 {
 	struct iio_channel *channel = pchg->chan[LP8788_VBATT];
-	int scaleint;
-	int scalepart;
-	int ret;
 
 	if (!channel)
 		return -EINVAL;
 
-	ret = iio_read_channel_scale(channel, &scaleint, &scalepart);
-	if (ret != IIO_VAL_INT_PLUS_MICRO)
-		return -EINVAL;
-
-	/* unit: mV */
-	*result = (scaleint + scalepart * 1000000) / 1000;
-
-	return 0;
+	return iio_read_channel_processed(channel, result);
 }
 
 static int lp8788_get_battery_voltage(struct lp8788_charger *pchg,
@@ -268,7 +257,7 @@ static int lp8788_get_battery_capacity(struct lp8788_charger *pchg,
 	struct lp8788 *lp = pchg->lp;
 	struct lp8788_charger_platform_data *pdata = pchg->pdata;
 	unsigned int max_vbatt;
-	unsigned int vbatt;
+	int vbatt;
 	enum lp8788_charging_state state;
 	u8 data;
 	int ret;
@@ -304,19 +293,18 @@ static int lp8788_get_battery_temperature(struct lp8788_charger *pchg,
 				union power_supply_propval *val)
 {
 	struct iio_channel *channel = pchg->chan[LP8788_BATT_TEMP];
-	int scaleint;
-	int scalepart;
+	int result;
 	int ret;
 
 	if (!channel)
 		return -EINVAL;
 
-	ret = iio_read_channel_scale(channel, &scaleint, &scalepart);
-	if (ret != IIO_VAL_INT_PLUS_MICRO)
+	ret = iio_read_channel_processed(channel, &result);
+	if (ret < 0)
 		return -EINVAL;
 
 	/* unit: 0.1 'C */
-	val->intval = (scaleint + scalepart * 1000000) / 100;
+	val->intval = result * 10;
 
 	return 0;
 }