1 .. SPDX-License-Identifier: GPL-2.0
2
3 The Virtual Media Controller Driver (vimc)
4 ==========================================
5
6 The vimc driver emulates complex video hardwar
7 API. It has a capture device and three subdevi
8
9 Topology
10 --------
11
12 The topology is hardcoded, although you could
13 recompile the driver to achieve your own topol
14
15 .. _vimc_topology_graph:
16
17 .. kernel-figure:: vimc.dot
18 :alt: Diagram of the default media pipel
19 :align: center
20
21 Media pipeline graph on vimc
22
23 Configuring the topology
24 ~~~~~~~~~~~~~~~~~~~~~~~~
25
26 Each subdevice will come with its default conf
27 width, ...). One needs to configure the topolo
28 configuration on each linked subdevice to stre
29 If the configuration doesn't match, the stream
30 package is a bundle of user-space applications
31 ``v4l2-ctl`` that can be used to configure the
32 of commands fits for the default topology:
33
34 .. code-block:: bash
35
36 media-ctl -d platform:vimc -V '"Sensor
37 media-ctl -d platform:vimc -V '"Debaye
38 media-ctl -d platform:vimc -V '"Scaler
39 media-ctl -d platform:vimc -V '"Scaler
40 media-ctl -d platform:vimc -V '"Scaler
41 v4l2-ctl -z platform:vimc -d "RGB/YUV
42 v4l2-ctl -z platform:vimc -d "Raw Capt
43
44 Subdevices
45 ----------
46
47 Subdevices define the behavior of an entity in
48 subdevice, the entity can have multiple pads o
49
50 vimc-sensor:
51 Generates images in several formats us
52 Exposes:
53
54 * 1 Pad source
55
56 vimc-lens:
57 Ancillary lens for a sensor. Supports
58 a vimc-sensor using an ancillary link.
59 control.
60
61 .. code-block:: bash
62
63 media-ctl -p
64 ...
65 - entity 28: Lens A (0 pad, 0 link)
66 type V4L2 subdev subty
67 device node name /dev/
68 - entity 29: Lens B (0 pad, 0 link)
69 type V4L2 subdev subty
70 device node name /dev/
71 v4l2-ctl -d /dev/v4l-subdev7 -C focus_
72 focus_absolute: 0
73
74
75 vimc-debayer:
76 Transforms images in bayer format into
77 Exposes:
78
79 * 1 Pad sink
80 * 1 Pad source
81
82 vimc-scaler:
83 Re-size the image to meet the source p
84 pad is configured to 360x480 and the s
85 be stretched to fit the source resolut
86 within the vimc limitations (even shri
87 Exposes:
88
89 * 1 Pad sink
90 * 1 Pad source
91
92 vimc-capture:
93 Exposes node /dev/videoX to allow user
94 Exposes:
95
96 * 1 Pad sink
97 * 1 Pad source
98
99 Module options
100 --------------
101
102 Vimc has a module parameter to configure the d
103
104 * ``allocator=<unsigned int>``
105
106 memory allocator selection, default is
107 will be allocated.
108
109 - 0: vmalloc
110 - 1: dma-contig
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