1 files changed, 5 insertions, 3 deletions

diff --git a/include/linux/iio/buffer.h b/include/linux/iio/buffer.h
index b65850a41127..eb8622b78ec9 100644
--- a/include/linux/iio/buffer.h
+++ b/include/linux/iio/buffer.h
@@ -21,8 +21,8 @@ struct iio_buffer;
  * struct iio_buffer_access_funcs - access functions for buffers.
  * @store_to:           actually store stuff to the buffer
  * @read_first_n:       try to get a specified number of bytes (must exist)
- * @data_available:     indicates whether data for reading from the buffer is
- *                      available.
+ * @data_available:     indicates how much data is available for reading from
+ *                      the buffer.
  * @request_update:     if a parameter change has been marked, update underlying
  *                      storage.
  * @set_bytes_per_datum:set number of bytes per datum
@@ -43,7 +43,7 @@ struct iio_buffer_access_funcs {
         int (*read_first_n)(struct iio_buffer *buffer,
                             size_t n,
                             char __user *buf);
-        bool (*data_available)(struct iio_buffer *buffer);
+        size_t (*data_available)(struct iio_buffer *buffer);
 
         int (*request_update)(struct iio_buffer *buffer);
 
@@ -72,6 +72,7 @@ struct iio_buffer_access_funcs {
  * @demux_bounce:       [INTERN] buffer for doing gather from incoming scan.
  * @buffer_list:        [INTERN] entry in the devices list of current buffers.
  * @ref:                [INTERN] reference count of the buffer.
+ * @watermark:          [INTERN] number of datums to wait for poll/read.
  */
 struct iio_buffer {
         int                                     length;
@@ -90,6 +91,7 @@ struct iio_buffer {
         void                                    *demux_bounce;
         struct list_head                        buffer_list;
         struct kref                             ref;
+        unsigned int                            watermark;
 };
 
 /**