From f453753900e99b26533ffa33588cfb35f59eaa15 Mon Sep 17 00:00:00 2001 From: Sean Nyekjaer Date: Wed, 3 May 2023 18:20:28 +0200 Subject: [PATCH] iio: adc: stm32-adc: skip adc-diff-channels setup if none is present commit 9c0d6ccd7d6bbd275e390b55a3390b4274291d95 upstream. If no adc differential channels are defined driver will fail with EINVAL: 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 Link: https://lore.kernel.org/r/20230503162029.3654093-1-sean@geanix.com Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/adc/stm32-adc.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c index b5d7ba2..a5d5b7b 100644 --- a/drivers/iio/adc/stm32-adc.c +++ b/drivers/iio/adc/stm32-adc.c @@ -1882,16 +1882,15 @@ static int stm32_adc_get_legacy_chan_count(struct iio_dev *indio_dev, struct stm * to get the *real* number of channels. */ ret = device_property_count_u32(dev, "st,adc-diff-channels"); - if (ret < 0) - return ret; - - ret /= (int)(sizeof(struct stm32_adc_diff_channel) / sizeof(u32)); - if (ret > adc_info->max_channels) { - dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n"); - return -EINVAL; - } else if (ret > 0) { - adc->num_diff = ret; - num_channels += ret; + if (ret > 0) { + ret /= (int)(sizeof(struct stm32_adc_diff_channel) / sizeof(u32)); + if (ret > adc_info->max_channels) { + dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n"); + return -EINVAL; + } else if (ret > 0) { + adc->num_diff = ret; + num_channels += ret; + } } /* Optional sample time is provided either for each, or all channels */ -- 2.7.4