Add iio backend support for synchronization status read.
The return value is a boolean stating if the data alignment has been
correctly performed and capture is synchronized. If successful, the
return value will be true.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
---
changes in v3:
 - update commit description.
 drivers/iio/industrialio-backend.c | 14 ++++++++++++++
 include/linux/iio/backend.h        |  3 +++
 2 files changed, 17 insertions(+)

diff --git a/drivers/iio/industrialio-backend.c b/drivers/iio/industrialio-backend.c
index b77a31b16aa5..f7c8167a248d 100644
--- a/drivers/iio/industrialio-backend.c
+++ b/drivers/iio/industrialio-backend.c
@@ -819,6 +819,20 @@ int iio_backend_data_alignment_disable(struct iio_backend *back)
 }
 EXPORT_SYMBOL_NS_GPL(iio_backend_data_alignment_disable, "IIO_BACKEND");
 
+/**
+ * iio_backend_sync_status_get - Read the syncronization status
+ * @back: Backend device
+ * @sync_en: Synchronization status returned (enabled or disabled)
+ *
+ * RETURNS:
+ * 0 on success, negative error number on failure.
+ */
+int iio_backend_sync_status_get(struct iio_backend *back, bool *sync_en)
+{
+	return iio_backend_op_call(back, sync_status_get, sync_en);
+}
+EXPORT_SYMBOL_NS_GPL(iio_backend_sync_status_get, "IIO_BACKEND");
+
 /**
  * iio_backend_ddr_enable - Enable interface DDR (Double Data Rate) mode
  * @back: Backend device
diff --git a/include/linux/iio/backend.h b/include/linux/iio/backend.h
index bd973de8cad9..e93d1a98e066 100644
--- a/include/linux/iio/backend.h
+++ b/include/linux/iio/backend.h
@@ -111,6 +111,7 @@ enum iio_backend_filter_type {
  * @filter_type_set: Set filter type.
  * @data_alignment_enable: Enable sync process.
  * @data_alignment_disable: Disable sync process.
+ * @sync_status_get: Get the syncronization status (enabled/disabled).
  * @ddr_enable: Enable interface DDR (Double Data Rate) mode.
  * @ddr_disable: Disable interface DDR (Double Data Rate) mode.
  * @data_stream_enable: Enable data stream.
@@ -165,6 +166,7 @@ struct iio_backend_ops {
 			       enum iio_backend_filter_type type);
 	int (*data_alignment_enable)(struct iio_backend *back);
 	int (*data_alignment_disable)(struct iio_backend *back);
+	int (*sync_status_get)(struct iio_backend *back, bool *sync_en);
 	int (*ddr_enable)(struct iio_backend *back);
 	int (*ddr_disable)(struct iio_backend *back);
 	int (*data_stream_enable)(struct iio_backend *back);
@@ -209,6 +211,7 @@ int iio_backend_filter_type_set(struct iio_backend *back,
 				enum iio_backend_filter_type type);
 int iio_backend_data_alignment_enable(struct iio_backend *back);
 int iio_backend_data_alignment_disable(struct iio_backend *back);
+int iio_backend_sync_status_get(struct iio_backend *back, bool *sync_en);
 int iio_backend_ddr_enable(struct iio_backend *back);
 int iio_backend_ddr_disable(struct iio_backend *back);
 int iio_backend_data_stream_enable(struct iio_backend *back);
-- 
2.49.0