If not set in chan_spec, cpu endianness used.
Signed-off-by: Jonathan Cameron <jic23@xxxxxxxxx>
---
Result of discussion in [PATCH 0/2] blue part 6: IIO abi rework.
Michael highlighted that we need to specify the endianness of buffer
contents. This patch does that. The IIO_CPU option exists so that
existing drivers which do conversion to cpu endian should work
without change.
Based on all sorts of fun I haven't pushed, so if you really want to
play with this see the iio-blue.git tree.
Jonathan
drivers/staging/iio/iio.h | 8 ++++++++
drivers/staging/iio/industrialio-ring.c | 15 ++++++++++++++-
2 files changed, 22 insertions(+), 1 deletions(-)
diff --git a/drivers/staging/iio/iio.h b/drivers/staging/iio/iio.h
index bde8b87..d09f84b 100644
--- a/drivers/staging/iio/iio.h
+++ b/drivers/staging/iio/iio.h
@@ -86,6 +86,12 @@ 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.
@@ -101,6 +107,7 @@ 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.
@@ -129,6 +136,7 @@ struct iio_chan_spec {
u8 realbits;
u8 storagebits;
u8 shift;
+ enum iio_endian endianness;
} scan_type;
const long info_mask;
const long event_mask;
diff --git a/drivers/staging/iio/industrialio-ring.c b/drivers/staging/iio/industrialio-ring.c
index 5edc6d8..aa1748b 100644
--- a/drivers/staging/iio/industrialio-ring.c
+++ b/drivers/staging/iio/industrialio-ring.c
@@ -24,6 +24,10 @@
#include "iio_core.h"
#include "ring_generic.h"
+const static char *iio_endian_prefix[] = {
+ [IIO_BE] = "be",
+ [IIO_LE] = "le",
+};
/**
* iio_ring_read_first_n_outer() - chrdev read for ring buffer access
@@ -95,7 +99,16 @@ 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,
--
1.7.3.4
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