Some sensors do not always start fast enough to read a valid ID from
registers at first attempt. Let's retry at most 3 times with short sleep
in between to fix random timing issues.
Signed-off-by: Matti Lehtimäki <matti.lehtimaki@xxxxxxxxx>
---
drivers/iio/common/st_sensors/st_sensors_core.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/iio/common/st_sensors/st_sensors_core.c b/drivers/iio/common/st_sensors/st_sensors_core.c
index 9910ba1da085..106f7953683e 100644
--- a/drivers/iio/common/st_sensors/st_sensors_core.c
+++ b/drivers/iio/common/st_sensors/st_sensors_core.c
@@ -21,6 +21,8 @@
#include "st_sensors_core.h"
+#define VERIFY_ID_RETRY_COUNT 3
+
int st_sensors_write_data_with_mask(struct iio_dev *indio_dev,
u8 reg_addr, u8 mask, u8 data)
{
@@ -619,11 +621,18 @@ EXPORT_SYMBOL_NS(st_sensors_get_settings_index, IIO_ST_SENSORS);
int st_sensors_verify_id(struct iio_dev *indio_dev)
{
struct st_sensor_data *sdata = iio_priv(indio_dev);
- int wai, err;
+ int wai, err, i;
if (sdata->sensor_settings->wai_addr) {
- err = regmap_read(sdata->regmap,
- sdata->sensor_settings->wai_addr, &wai);
+ for (i = 0; i < VERIFY_ID_RETRY_COUNT; i++) {
+ err = regmap_read(sdata->regmap,
+ sdata->sensor_settings->wai_addr, &wai);
+
+ if (!err && sdata->sensor_settings->wai == wai)
+ return 0;
+
+ msleep(20);
+ }
if (err < 0) {
dev_err(&indio_dev->dev,
"failed to read Who-Am-I register.\n");
--
2.34.1
