iio: adc: ad_sigma_delta: Export ad_sd_calibrate

This patch exports the ad_sd_calibrate function in order to be able to
call it from outside ad_sigma_delta.

There are cases where the option to calibrate one channel at a time is
necessary (ex. system calibration for zero scale and full scale).
Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ad_sigma_delta.c

@@ -205,7 +205,7 @@ int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
 }
 EXPORT_SYMBOL_GPL(ad_sd_reset);
 
-static int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
+int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
 	unsigned int mode, unsigned int channel)
 {
 	int ret;
@@ -242,6 +242,7 @@ static int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(ad_sd_calibrate);
 
 /**
  * ad_sd_calibrate_all() - Performs channel calibration

include/linux/iio/adc/ad_sigma_delta.h

@@ -119,6 +119,8 @@ int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
 
 int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
 	const struct iio_chan_spec *chan, int *val);
+int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
+	unsigned int mode, unsigned int channel);
 int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
 	const struct ad_sd_calib_data *cd, unsigned int n);
 int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev,