iio: adc: max1027: Reset the device at probe time

BugLink: https://bugs.launchpad.net/bugs/1858462

[ Upstream commit db033831 ]

All the registers are configured by the driver, let's reset the chip
at probe time, avoiding any conflict with a possible earlier
configuration.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/iio/adc/max1027.c

@@ -470,6 +470,14 @@ static int max1027_probe(struct spi_device *spi)
 		goto fail_dev_register;
 	}
 
+	/* Internal reset */
+	st->reg = MAX1027_RST_REG;
+	ret = spi_write(st->spi, &st->reg, 1);
+	if (ret < 0) {
+		dev_err(&indio_dev->dev, "Failed to reset the ADC\n");
+		return ret;
+	}
+
 	/* Disable averaging */
 	st->reg = MAX1027_AVG_REG;
 	ret = spi_write(st->spi, &st->reg, 1);