If only adc differential channels are defined driver will fail with
stm32-adc: probe of 48003000.adc:adc@0 failed with error -22
Fix this by skipping the initialization if no channels are defined.
This applies only to the legacy way of initializing adc channels.
Fixes: d7705f35448a ("iio: adc: stm32-adc: convert to device properties")
Signed-off-by: Sean Nyekjaer <sean@xxxxxxxxxx>
---
Changes since v1:
- Ignore extra channel for timestamps in PIO mode
- Use single ended count in channel creation (Thanks Olivier Moysan)
Changes since v2:
- Avoid calling device_property_read_u32_array with num_se 0 (Thanks Olivier Moysan)
drivers/iio/adc/stm32-adc.c | 42 ++++++++++++++++++++-----------------
1 file changed, 23 insertions(+), 19 deletions(-)
diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index 14524c1b5583..f7613efb870d 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -2038,6 +2038,7 @@ static int stm32_adc_legacy_chan_init(struct iio_dev *indio_dev,
struct stm32_adc_diff_channel diff[STM32_ADC_CH_MAX];
struct device *dev = &indio_dev->dev;
u32 num_diff = adc->num_diff;
+ int num_se = nchans - num_diff;
int size = num_diff * sizeof(*diff) / sizeof(u32);
int scan_index = 0, ret, i, c;
u32 smp = 0, smps[STM32_ADC_CH_MAX], chans[STM32_ADC_CH_MAX];
@@ -2064,29 +2065,32 @@ static int stm32_adc_legacy_chan_init(struct iio_dev *indio_dev,
scan_index++;
}
}
-
- ret = device_property_read_u32_array(dev, "st,adc-channels", chans,
- nchans);
- if (ret)
- return ret;
-
- for (c = 0; c < nchans; c++) {
- if (chans[c] >= adc_info->max_channels) {
- dev_err(&indio_dev->dev, "Invalid channel %d\n",
- chans[c]);
- return -EINVAL;
+ if (num_se > 0) {
+ ret = device_property_read_u32_array(dev, "st,adc-channels", chans, num_se);
+ if (ret) {
+ dev_err(&indio_dev->dev, "Failed to get st,adc-channels %d\n", ret);
+ return ret;
}
- /* Channel can't be configured both as single-ended & diff */
- for (i = 0; i < num_diff; i++) {
- if (chans[c] == diff[i].vinp) {
- dev_err(&indio_dev->dev, "channel %d misconfigured\n", chans[c]);
+ for (c = 0; c < num_se; c++) {
+ if (chans[c] >= adc_info->max_channels) {
+ dev_err(&indio_dev->dev, "Invalid channel %d\n",
+ chans[c]);
return -EINVAL;
}
+
+ /* Channel can't be configured both as single-ended & diff */
+ for (i = 0; i < num_diff; i++) {
+ if (chans[c] == diff[i].vinp) {
+ dev_err(&indio_dev->dev, "channel %d misconfigured\n",
+ chans[c]);
+ return -EINVAL;
+ }
+ }
+ stm32_adc_chan_init_one(indio_dev, &channels[scan_index],
+ chans[c], 0, scan_index, false);
+ scan_index++;
}
- stm32_adc_chan_init_one(indio_dev, &channels[scan_index],
- chans[c], 0, scan_index, false);
- scan_index++;
}
if (adc->nsmps > 0) {
@@ -2307,7 +2311,7 @@ static int stm32_adc_chan_fw_init(struct iio_dev *indio_dev, bool timestamping)
if (legacy)
ret = stm32_adc_legacy_chan_init(indio_dev, adc, channels,
- num_channels);
+ timestamping ? num_channels - 1 : num_channels);
else
ret = stm32_adc_generic_chan_init(indio_dev, adc, channels);
if (ret < 0)
--
2.40.0
