[PATCH v7 2/6] iio: Replace 'sign' field with union in struct iio_scan_type

[Francesco Lavra <flavra@baylibre.com>]

This field is used to differentiate between signed and unsigned integers.
A following commit will extend its use in order to add support for non-
integer scan elements; therefore, replace it with a union that contains a
more generic 'format' field. This union will be dropped when all drivers
are changed to use the format field.

Signed-off-by: Francesco Lavra <flavra@baylibre.com>
---
 Documentation/driver-api/iio/buffers.rst | 4 ++--
 include/linux/iio/iio.h                  | 7 +++++--
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/Documentation/driver-api/iio/buffers.rst b/Documentation/driver-api/iio/buffers.rst
index 63f364e862d1..f36e6d00173f 100644
--- a/Documentation/driver-api/iio/buffers.rst
+++ b/Documentation/driver-api/iio/buffers.rst
@@ -78,7 +78,7 @@ fields in iio_chan_spec definition::
    /* other members */
            int scan_index
            struct {
-                   char sign;
+                   char format;
                    u8 realbits;
                    u8 storagebits;
                    u8 shift;
@@ -98,7 +98,7 @@ following channel definition::
 		   /* other stuff here */
 		   .scan_index = 0,
 		   .scan_type = {
-		           .sign = 's',
+		           .format = 's',
 			   .realbits = 12,
 			   .storagebits = 16,
 			   .shift = 4,
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index a9ecff191bd9..61f1dfc14e02 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -178,7 +178,7 @@ struct iio_event_spec {
 
 /**
  * struct iio_scan_type - specification for channel data format in buffer
- * @sign:		's' or 'u' to specify signed or unsigned
+ * @format:		(signed or unsigned) integer, or floating point
  * @realbits:		Number of valid bits of data
  * @storagebits:	Realbits + padding
  * @shift:		Shift right by this before masking out realbits.
@@ -189,7 +189,10 @@ struct iio_event_spec {
  * @endianness:		little or big endian
  */
 struct iio_scan_type {
-	char	sign;
+	union {
+		char sign;
+		char format;
+	};
 	u8	realbits;
 	u8	storagebits;
 	u8	shift;
-- 
2.39.5