Unverified Commit 75604180 authored by Herve Codina's avatar Herve Codina Committed by Mark Brown
Browse files

iio: inkern: Add a helper to query an available minimum raw value 



A helper, iio_read_max_channel_raw() exists to read the available
maximum raw value of a channel but nothing similar exists to read the
available minimum raw value.

This new helper, iio_read_min_channel_raw(), fills the hole and can be
used for reading the available minimum raw value of a channel.
It is fully based on the existing iio_read_max_channel_raw().

Signed-off-by: default avatarHerve Codina <herve.codina@bootlin.com>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/20230623085830.749991-11-herve.codina@bootlin.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 4dc60373

drivers/iio/inkern.c

+63 −0
Original line number Diff line number Diff line
@@ -909,6 +909,69 @@ int iio_read_max_channel_raw(struct iio_channel *chan, int *val) 
}

EXPORT_SYMBOL_GPL(iio_read_max_channel_raw);



static int iio_channel_read_min(struct iio_channel *chan,

				int *val, int *val2, int *type,

				enum iio_chan_info_enum info)

{

	const int *vals;

	int length;

	int ret;



	ret = iio_channel_read_avail(chan, &vals, type, &length, info);

	if (ret < 0)

		return ret;



	switch (ret) {

	case IIO_AVAIL_RANGE:

		switch (*type) {

		case IIO_VAL_INT:

			*val = vals[0];

			break;

		default:

			*val = vals[0];

			if (val2)

				*val2 = vals[1];

		}

		return 0;



	case IIO_AVAIL_LIST:

		if (length <= 0)

			return -EINVAL;

		switch (*type) {

		case IIO_VAL_INT:

			*val = min_array(vals, length);

			break;

		default:

			/* TODO: learn about min for other iio values */

			return -EINVAL;

		}

		return 0;



	default:

		return -EINVAL;

	}

}



int iio_read_min_channel_raw(struct iio_channel *chan, int *val)

{

	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);

	int ret;

	int type;



	mutex_lock(&iio_dev_opaque->info_exist_lock);

	if (!chan->indio_dev->info) {

		ret = -ENODEV;

		goto err_unlock;

	}



	ret = iio_channel_read_min(chan, val, NULL, &type, IIO_CHAN_INFO_RAW);

err_unlock:

	mutex_unlock(&iio_dev_opaque->info_exist_lock);



	return ret;

}

EXPORT_SYMBOL_GPL(iio_read_min_channel_raw);



int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)

{

	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);

include/linux/iio/consumer.h

+12 −0
Original line number Diff line number Diff line
@@ -301,6 +301,18 @@ int iio_write_channel_raw(struct iio_channel *chan, int val); 
 */

int iio_read_max_channel_raw(struct iio_channel *chan, int *val);



/**

 * iio_read_min_channel_raw() - read minimum available raw value from a given

 *				channel, i.e. the minimum possible value.

 * @chan:		The channel being queried.

 * @val:		Value read back.

 *

 * Note, if standard units are required, raw reads from iio channels

 * need the offset (default 0) and scale (default 1) to be applied

 * as (raw + offset) * scale.

 */

int iio_read_min_channel_raw(struct iio_channel *chan, int *val);



/**

 * iio_read_avail_channel_raw() - read available raw values from a given channel

 * @chan:		The channel being queried.