[PATCH v4 03/14] iio: backend: Add support for CRC

Add a backend operation to enable or disable direction-specific CRC
handling. On input data paths, the backend handles CRC data generated by
the frontend. On output data paths, the backend generates CRC data for
the frontend to verify.

Signed-off-by: Janani Sunil <[email protected]>
---
 drivers/iio/industrialio-backend.c | 33 +++++++++++++++++++++++++++++++++
 include/linux/iio/backend.h        |  6 ++++++
 2 files changed, 39 insertions(+)

diff --git a/drivers/iio/industrialio-backend.c b/drivers/iio/industrialio-backend.c
index f7a4be8ec320..fbf5c39d7655 100644
--- a/drivers/iio/industrialio-backend.c
+++ b/drivers/iio/industrialio-backend.c
@@ -886,6 +886,39 @@ int iio_backend_num_lanes_set(struct iio_backend *back, unsigned int num_lanes)
 }
 EXPORT_SYMBOL_NS_GPL(iio_backend_num_lanes_set, "IIO_BACKEND");
 
+/**
+ * iio_backend_crc_enable - Enable CRC handling
+ * @back: Backend device
+ *
+ * On input data paths, enable backend handling of CRC data generated by the
+ * frontend. On output data paths, enable the backend to generate CRC data for
+ * the frontend to verify.
+ *
+ * RETURNS:
+ * 0 on success, negative error number on failure.
+ */
+int iio_backend_crc_enable(struct iio_backend *back)
+{
+	return iio_backend_op_call(back, crc_enable);
+}
+EXPORT_SYMBOL_NS_GPL(iio_backend_crc_enable, "IIO_BACKEND");
+
+/**
+ * iio_backend_crc_disable - Disable CRC handling
+ * @back: Backend device
+ *
+ * On input data paths, disable backend handling of CRC data generated by the
+ * frontend. On output data paths, disable CRC generation by the backend.
+ *
+ * RETURNS:
+ * 0 on success, negative error number on failure.
+ */
+int iio_backend_crc_disable(struct iio_backend *back)
+{
+	return iio_backend_op_call(back, crc_disable);
+}
+EXPORT_SYMBOL_NS_GPL(iio_backend_crc_disable, "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 3f95ed1fdf9e..9c16b695a602 100644
--- a/include/linux/iio/backend.h
+++ b/include/linux/iio/backend.h
@@ -133,6 +133,8 @@ enum iio_backend_capabilities {
  * @filter_type_set: Set filter type.
  * @interface_data_align: Perform the data alignment process.
  * @num_lanes_set: Set the number of lanes enabled.
+ * @crc_enable: Enable direction-specific CRC handling.
+ * @crc_disable: Disable direction-specific CRC handling.
  * @ddr_enable: Enable interface DDR (Double Data Rate) mode.
  * @ddr_disable: Disable interface DDR (Double Data Rate) mode.
  * @data_stream_enable: Enable data stream.
@@ -189,6 +191,8 @@ struct iio_backend_ops {
 			       enum iio_backend_filter_type type);
 	int (*interface_data_align)(struct iio_backend *back, u32 timeout_us);
 	int (*num_lanes_set)(struct iio_backend *back, unsigned int num_lanes);
+	int (*crc_enable)(struct iio_backend *back);
+	int (*crc_disable)(struct iio_backend *back);
 	int (*ddr_enable)(struct iio_backend *back);
 	int (*ddr_disable)(struct iio_backend *back);
 	int (*data_stream_enable)(struct iio_backend *back);
@@ -237,6 +241,8 @@ int iio_backend_filter_type_set(struct iio_backend *back,
 				enum iio_backend_filter_type type);
 int iio_backend_interface_data_align(struct iio_backend *back, u32 timeout_us);
 int iio_backend_num_lanes_set(struct iio_backend *back, unsigned int num_lanes);
+int iio_backend_crc_enable(struct iio_backend *back);
+int iio_backend_crc_disable(struct iio_backend *back);
 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);

-- 
2.43.0