[PATCH v4 1/4] iio: core: introduce trough modifier for minimum values

[Li peiyu <579lpy@gmail.com>]

From: Javier Carrasco <javier.carrasco.cruz@gmail.com>

The IIO_CHAN_INFO_PEAK modifier is used for maximum values and currently
there is no equivalent for minimum values. Instead of overloading the
existing peak modifier, a new modifier can be added.

In principle there is no need to add a _TROUGH_SCALE modifier as the
scale will be the same as the one required for the INFO_PEAK modifier,
which in turn is sometimes omitted if a single scale for peaks and raw
values is required.

Add an IIO_CHAN_INFO_TROUGH modifier for minimum values.

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
---
 drivers/iio/industrialio-core.c | 1 +
 include/linux/iio/types.h       | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index c77745b594bd..351c64c2f4da 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -182,6 +182,7 @@ static const char * const iio_chan_info_postfix[] = {
 	[IIO_CHAN_INFO_THERMOCOUPLE_TYPE] = "thermocouple_type",
 	[IIO_CHAN_INFO_CALIBAMBIENT] = "calibambient",
 	[IIO_CHAN_INFO_ZEROPOINT] = "zeropoint",
+	[IIO_CHAN_INFO_TROUGH] = "trough_raw",
 };
 /**
  * iio_device_id() - query the unique ID for the device
diff --git a/include/linux/iio/types.h b/include/linux/iio/types.h
index 117bde7d6ad7..d89982c98368 100644
--- a/include/linux/iio/types.h
+++ b/include/linux/iio/types.h
@@ -68,6 +68,7 @@ enum iio_chan_info_enum {
 	IIO_CHAN_INFO_THERMOCOUPLE_TYPE,
 	IIO_CHAN_INFO_CALIBAMBIENT,
 	IIO_CHAN_INFO_ZEROPOINT,
+	IIO_CHAN_INFO_TROUGH,
 };
 
 #endif /* _IIO_TYPES_H_ */
-- 
2.34.1