driver-api/media/csi2.rst

1 .. SPDX-License-Identifier: GPL-2.0
5 MIPI CSI-2
8 CSI-2 is a data bus intended for transferring images from cameras to
14 -----------------
16 See :ref:`v4l2-mbus-pixelcode` for details on which media bus formats should
17 be used for CSI-2 interfaces.
20 -------------------
22 CSI-2 transmitter, such as a sensor or a TV tuner, drivers need to
23 provide the CSI-2 receiver with information on the CSI-2 bus
26 (:c:type:`v4l2_subdev_video_ops`->s_stream() callback). These
27 interface elements must be present on the sub-device represents the
28 CSI-2 transmitter.
34 :c:type:`v4l2_subdev_video_ops`->s_stream() callback provides an
39 	pixel_rate = link_freq * 2 * nr_of_lanes / bits_per_sample
43 .. list-table:: variables in pixel rate calculation
44    :header-rows: 1
46    * - variable or constant
47      - description
48    * - link_freq
49      - The value of the V4L2_CID_LINK_FREQ integer64 menu item.
50    * - nr_of_lanes
51      - Number of data lanes used on the CSI-2 link. This can
53    * - 2
54      - Two bits are transferred per clock cycle per lane.
55    * - bits_per_sample
56      - Number of bits per sample.
58 The transmitter drivers must, if possible, configure the CSI-2
59 transmitter to *LP-11 mode* whenever the transmitter is powered on but
60 not active, and maintain *LP-11 mode* until stream on. Only at stream
79 ----------------
81 Before the receiver driver may enable the CSI-2 transmitter by using
82 the :c:type:`v4l2_subdev_video_ops`->s_stream(), it must have powered
84 :c:type:`v4l2_subdev_core_ops`->s_power() callback. This may take
89 -------