[PATCH v3 3/4] media: Documentation: Update link frequency driver documentation

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Add the get_mbus_config() as the means for conveying the link frequency
towards the receiver drivers.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 Documentation/driver-api/media/tx-rx.rst | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/driver-api/media/tx-rx.rst b/Documentation/driver-api/media/tx-rx.rst
index 29d66a47b56e..2f22a1534da9 100644
--- a/Documentation/driver-api/media/tx-rx.rst
+++ b/Documentation/driver-api/media/tx-rx.rst
@@ -49,6 +49,10 @@ Link frequency
 The :ref:`V4L2_CID_LINK_FREQ <v4l2-cid-link-freq>` control is used to tell the
 receiver the frequency of the bus (i.e. it is not the same as the symbol rate).
 
+For devices where the link frequency is read-only, the link_freq field of struct
+v4l2_mbus_config is recommended over controls for conveying the link frequency
+to the downstream driver in the pipeline.
+
 ``.s_stream()`` callback
 ^^^^^^^^^^^^^^^^^^^^^^^^
 
-- 
2.39.2