[PATCH 1/4] iio: adc: ad7124: fix chip ID mismatch

From: Dumitru Ceclan
Date: Wed Jul 31 2024 - 08:37:45 EST


The ad7124_soft_reset() function has the assumption that the chip will
assert the "power-on reset" bit in the STATUS register after a software
reset without any delay. The POR bit =0 is used to check if the chip
initialization is done.

A chip ID mismatch probe error appears intermittently when the probe
continues too soon and the ID register does not contain the expected
value.

Fix by adding a 200us delay after the software reset command is issued.

Fixes: b3af341bbd96 ("iio: adc: Add ad7124 support")
Signed-off-by: Dumitru Ceclan <dumitru.ceclan@xxxxxxxxxx>
---
drivers/iio/adc/ad7124.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c
index e7b1d517d3de..54d4c5597696 100644
--- a/drivers/iio/adc/ad7124.c
+++ b/drivers/iio/adc/ad7124.c
@@ -762,6 +762,7 @@ static int ad7124_soft_reset(struct ad7124_state *st)
if (ret < 0)
return ret;

+ fsleep(200);
timeout = 100;
do {
ret = ad_sd_read_reg(&st->sd, AD7124_STATUS, 1, &readval);

--
2.43.0