@@ -29,6 +29,20 @@ used in the system. Using another frequency may cause harmful effects
elsewhere. Therefore only the pre-determined frequencies are configurable by the
user.
+On choosing link frequencies
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Choosing link frequencies for a board is generally a part of the hardware design
+process as one needs to ensure an EMC-safe frequency the sensor supports with
+the given external clock frequency exists. On development systems this may be
+less than an immediate concern, so more or less anything that sensor and the
+rest of the applicable hardware supports can be used.
+
+If the sensor's PLL tree is not documented and all that is available are
+register lists, even knowing the frequency a driver uses may be difficult. This
+could still be :ref:`calculated from the number of lanes, sensor's output image
+size, blanking values and frame rate <media_camera_raw_frame_interval>`.
+
ACPI
~~~~
@@ -44,6 +44,8 @@ There are two different methods for obtaining possibilities for different frame
intervals as well as configuring the frame interval. Which one to implement
depends on the type of the device.
+.. _media_camera_raw_frame_interval:
+
Raw camera sensors
~~~~~~~~~~~~~~~~~~
Document how link frequencies can be selected for the link-frequencies property. Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> --- Documentation/driver-api/media/camera-sensor.rst | 14 ++++++++++++++ .../userspace-api/media/drivers/camera-sensor.rst | 2 ++ 2 files changed, 16 insertions(+)