iio: adc: stm32-adc: skip adc-channels setup if none is present

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: d7705f3544 ("iio: adc: stm32-adc: convert to device properties")
Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Reviewed-by: Olivier Moysan <olivier.moysan@foss.st.com>
Link: https://lore.kernel.org/r/20230503162029.3654093-2-sean@geanix.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Sean Nyekjaer 2023-05-03 18:20:29 +02:00 committed by Jonathan Cameron
parent 9c0d6ccd7d
commit 3e27ef0ced

View File

@ -2036,6 +2036,7 @@ 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];
@ -2062,29 +2063,32 @@ 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) {
@ -2305,7 +2309,7 @@ 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)