staging:iio:scan element types: introduce endian description to the d…

…ata format.

If not set in chan_spec, cpu endianness used.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/iio.h

@@ -80,6 +80,12 @@ enum iio_chan_info_enum {
 	IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW_SEPARATE,
 };
 
+enum iio_endian {
+	IIO_CPU,
+	IIO_BE,
+	IIO_LE,
+};
+
 /**
  * struct iio_chan_spec - specification of a single channel
  * @type:		What type of measurement is the channel making.
@@ -95,6 +101,7 @@ enum iio_chan_info_enum {
  *			storage_bits:	Realbits + padding
  *			shift:		Shift right by this before masking out
  *					realbits.
+ *			endianness:	little or big endian
  * @info_mask:		What information is to be exported about this channel.
  *			This includes calibbias, scale etc.
  * @event_mask:	What events can this channel produce.
@@ -123,6 +130,7 @@ struct iio_chan_spec {
 		u8	realbits;
 		u8	storagebits;
 		u8	shift;
+		enum iio_endian endianness;
 	} scan_type;
 	long			info_mask;
 	long			event_mask;

drivers/staging/iio/industrialio-ring.c

@@ -25,6 +25,10 @@
 #include "sysfs.h"
 #include "ring_generic.h"
 
+static const char * const iio_endian_prefix[] = {
+	[IIO_BE] = "be",
+	[IIO_LE] = "le",
+};
 
 /**
  * iio_ring_read_first_n_outer() - chrdev read for ring buffer access
@@ -96,7 +100,16 @@ static ssize_t iio_show_fixed_type(struct device *dev,
 				   char *buf)
 {
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
-	return sprintf(buf, "%c%d/%d>>%u\n",
+	u8 type = this_attr->c->scan_type.endianness;
+
+	if (type == IIO_CPU) {
+		if (__LITTLE_ENDIAN)
+			type = IIO_LE;
+		else
+			type = IIO_BE;
+	}
+	return sprintf(buf, "%s:%c%d/%d>>%u\n",
+		       iio_endian_prefix[type],
 		       this_attr->c->scan_type.sign,
 		       this_attr->c->scan_type.realbits,
 		       this_attr->c->scan_type.storagebits,