1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/hwmon/ads7828.c b/drivers/hwmon/ads7828.c
index 6c99ee7bafa3..ee396ff167d9 100644
--- a/drivers/hwmon/ads7828.c
+++ b/drivers/hwmon/ads7828.c
@@ -120,6 +120,7 @@ static int ads7828_probe(struct i2c_client *client,
         unsigned int vref_mv = ADS7828_INT_VREF_MV;
         bool diff_input = false;
         bool ext_vref = false;
+        unsigned int regval;
 
         data = devm_kzalloc(dev, sizeof(struct ads7828_data), GFP_KERNEL);
         if (!data)
@@ -154,6 +155,15 @@ static int ads7828_probe(struct i2c_client *client,
         if (!diff_input)
                 data->cmd_byte |= ADS7828_CMD_SD_SE;
 
+        /*
+         * Datasheet specifies internal reference voltage is disabled by
+         * default. The internal reference voltage needs to be enabled and
+         * voltage needs to settle before getting valid ADC data. So perform a
+         * dummy read to enable the internal reference voltage.
+         */
+        if (!ext_vref)
+                regmap_read(data->regmap, data->cmd_byte, &regval);
+
         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
                                                            data,
                                                            ads7828_groups);