From 8050ab260b3e7ffd5ef52ab5e6da9b254587ca52 Mon Sep 17 00:00:00 2001 From: Sean Nyekjaer Date: Wed, 10 May 2023 10:59:38 +0200 Subject: [PATCH] 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: d7705f35448a ("iio: adc: stm32-adc: convert to device properties") Signed-off-by: Sean Nyekjaer Reviewed-by: Olivier Moysan Link: https://lore.kernel.org/r/20230503162029.3654093-2-sean@geanix.com Cc: Signed-off-by: Jonathan Cameron Change-Id: Ie16dd1c1326fd84c0a4daa46205cbf498741d449 Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/linux-stm32/+/305094 ACI: CITOOLS ACI: CIBUILD Tested-by: Olivier MOYSAN Reviewed-by: Olivier MOYSAN Reviewed-by: Fabrice GASNIER Domain-Review: Fabrice GASNIER --- drivers/iio/adc/stm32-adc.c | 44 +++++++++++++++++++------------------ 1 file changed, 23 insertions(+), 21 deletions(-) diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c index 5f5caf5688d8..04a4fa49c13c 100644 --- a/drivers/iio/adc/stm32-adc.c +++ b/drivers/iio/adc/stm32-adc.c @@ -2174,6 +2174,7 @@ 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]; @@ -2200,31 +2201,32 @@ 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 - num_diff); - if (ret) { - dev_err(&indio_dev->dev, "Failed to get st,adc-channels %d\n", ret); - return ret; - } - - for (c = 0; c < (nchans - num_diff); 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) { @@ -2445,7 +2447,7 @@ 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)