[PATCH v4 04/16] iio: adc: at91-sama5d2_adc: add condition to validate calibration data

[Varshini Rajendran <varshini.rajendran@microchip.com>]

Add additional condition to validate the calibration data read from the
NVMEM cell using the TAG of the packet.

Signed-off-by: Varshini Rajendran <varshini.rajendran@microchip.com>
---
 drivers/iio/adc/at91-sama5d2_adc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index 798e4d60bf69..15dc88f4961b 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -2297,7 +2297,8 @@ static int at91_adc_temp_sensor_init(struct at91_adc_state *st,
 		return dev_err_probe(dev, PTR_ERR(buf),
 				     "Failed to read calibration data!\n");
 
-	if (len < layout->min_len * sizeof(*buf)) {
+	if (len < layout->min_len * sizeof(*buf) ||
+	    buf[layout->tag_idx] != AT91_TEMP_CALIB_TAG_ACST) {
 		dev_err(dev, "Invalid calibration data!\n");
 		return -EINVAL;
 	}
-- 
2.34.1