[PATCH 1/8] iio: adc: stm32-adc: fix channel sampling time init

Olivier Moysan
2022-09-28T16:43:47Z

Fix channel init for ADC generic channel bindings.
In generic channel initialization, stm32_adc_smpr_init() is called
to initialize channel sampling time. The "st,min-sample-time-ns"
property is an optional property. If it is not defined,
stm32_adc_smpr_init() is currently skipped. However stm32_adc_smpr_init()
must always be called, to force a minimum sampling time for
the internal channels, as the minimum sampling time is known.
Make stm32_adc_smpr_init() call unconditional.

Fixes: 796e5d0b1e9b ("iio: adc: stm32-adc: use generic binding for sample-time")

Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com>
---
drivers/iio/adc/stm32-adc.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index 6256977eb7f7..3cda529f081d 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -2086,18 +2086,19 @@ static int stm32_adc_generic_chan_init(struct iio_dev *indio_dev,
stm32_adc_chan_init_one(indio_dev, &channels[scan_index], val,
vin[1], scan_index, differential);

+ val = 0;
ret = fwnode_property_read_u32(child, "st,min-sample-time-ns", &val);
/* st,min-sample-time-ns is optional */
- if (!ret) {
- stm32_adc_smpr_init(adc, channels[scan_index].channel, val);
- if (differential)
- stm32_adc_smpr_init(adc, vin[1], val);
- } else if (ret != -EINVAL) {
+ if (ret && ret != -EINVAL) {
dev_err(&indio_dev->dev, "Invalid st,min-sample-time-ns property %d\n",
ret);
goto err;
}

+ stm32_adc_smpr_init(adc, channels[scan_index].channel, val);
+ if (differential)
+ stm32_adc_smpr_init(adc, vin[1], val);
+
scan_index++;
}