1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 %YAML 1.2
3 ---
4 $id: http://devicetree.org/schemas/media/video-interfaces.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6
7 title: Common Properties for Video Receiver and Transmitter Interface Endpoints
8
9 maintainers:
10 - Sakari Ailus <sakari.ailus@linux.intel.com>
11 - Laurent Pinchart <laurent.pinchart@ideasonboard.com>
12
13 description: |
14 Video data pipelines usually consist of external devices, e.g. camera sensors,
15 controlled over an I2C, SPI or UART bus, and SoC internal IP blocks, including
16 video DMA engines and video data processors.
17
18 SoC internal blocks are described by DT nodes, placed similarly to other SoC
19 blocks. External devices are represented as child nodes of their respective
20 bus controller nodes, e.g. I2C.
21
22 Data interfaces on all video devices are described by their child 'port' nodes.
23 Configuration of a port depends on other devices participating in the data
24 transfer and is described by 'endpoint' subnodes.
25
26 device {
27 ...
28 ports {
29 #address-cells = <1>;
30 #size-cells = <0>;
31
32 port@0 {
33 ...
34 endpoint@0 { ... };
35 endpoint@1 { ... };
36 };
37 port@1 { ... };
38 };
39 };
40
41 If a port can be configured to work with more than one remote device on the same
42 bus, an 'endpoint' child node must be provided for each of them. If more than
43 one port is present in a device node or there is more than one endpoint at a
44 port, or port node needs to be associated with a selected hardware interface,
45 a common scheme using '#address-cells', '#size-cells' and 'reg' properties is
46 used.
47
48 All 'port' nodes can be grouped under optional 'ports' node, which allows to
49 specify #address-cells, #size-cells properties independently for the 'port'
50 and 'endpoint' nodes and any child device nodes a device might have.
51
52 Two 'endpoint' nodes are linked with each other through their 'remote-endpoint'
53 phandles. An endpoint subnode of a device contains all properties needed for
54 configuration of this device for data exchange with other device. In most
55 cases properties at the peer 'endpoint' nodes will be identical, however they
56 might need to be different when there is any signal modifications on the bus
57 between two devices, e.g. there are logic signal inverters on the lines.
58
59 It is allowed for multiple endpoints at a port to be active simultaneously,
60 where supported by a device. For example, in case where a data interface of
61 a device is partitioned into multiple data busses, e.g. 16-bit input port
62 divided into two separate ITU-R BT.656 8-bit busses. In such case bus-width
63 and data-shift properties can be used to assign physical data lines to each
64 endpoint node (logical bus).
65
66 Documenting bindings for devices
67 --------------------------------
68
69 All required and optional bindings the device supports shall be explicitly
70 documented in device DT binding documentation. This also includes port and
71 endpoint nodes for the device, including unit-addresses and reg properties
72 where relevant.
73
74 allOf:
75 - $ref: /schemas/graph.yaml#/$defs/endpoint-base
76
77 properties:
78 slave-mode:
79 type: boolean
80 description:
81 Indicates that the link is run in slave mode. The default when this
82 property is not specified is master mode. In the slave mode horizontal and
83 vertical synchronization signals are provided to the slave device (data
84 source) by the master device (data sink). In the master mode the data
85 source device is also the source of the synchronization signals.
86
87 bus-type:
88 $ref: /schemas/types.yaml#/definitions/uint32
89 enum:
90 - 1 # MIPI CSI-2 C-PHY
91 - 2 # MIPI CSI1
92 - 3 # CCP2
93 - 4 # MIPI CSI-2 D-PHY
94 - 5 # Parallel
95 - 6 # BT.656
96 - 7 # DPI
97 description:
98 Data bus type.
99
100 bus-width:
101 $ref: /schemas/types.yaml#/definitions/uint32
102 maximum: 64
103 description:
104 Number of data lines actively used, valid for the parallel busses.
105
106 data-shift:
107 $ref: /schemas/types.yaml#/definitions/uint32
108 maximum: 64
109 description:
110 On the parallel data busses, if bus-width is used to specify the number of
111 data lines, data-shift can be used to specify which data lines are used,
112 e.g. "bus-width=<8>; data-shift=<2>;" means, that lines 9:2 are used.
113
114 hsync-active:
115 $ref: /schemas/types.yaml#/definitions/uint32
116 enum: [ 0, 1 ]
117 description:
118 Active state of the HSYNC signal, 0/1 for LOW/HIGH respectively.
119
120 vsync-active:
121 $ref: /schemas/types.yaml#/definitions/uint32
122 enum: [ 0, 1 ]
123 description:
124 Active state of the VSYNC signal, 0/1 for LOW/HIGH respectively. Note,
125 that if HSYNC and VSYNC polarities are not specified, embedded
126 synchronization may be required, where supported.
127
128 data-active:
129 $ref: /schemas/types.yaml#/definitions/uint32
130 enum: [ 0, 1 ]
131 description:
132 Similar to HSYNC and VSYNC, specifies data line polarity.
133
134 data-enable-active:
135 $ref: /schemas/types.yaml#/definitions/uint32
136 enum: [ 0, 1 ]
137 description:
138 Similar to HSYNC and VSYNC, specifies the data enable signal polarity.
139
140 field-even-active:
141 $ref: /schemas/types.yaml#/definitions/uint32
142 enum: [ 0, 1 ]
143 description:
144 Field signal level during the even field data transmission.
145
146 pclk-sample:
147 $ref: /schemas/types.yaml#/definitions/uint32
148 enum: [ 0, 1, 2 ]
149 description:
150 Sample data on falling (0), rising (1) or both (2) edges of the pixel
151 clock signal.
152
153 sync-on-green-active:
154 $ref: /schemas/types.yaml#/definitions/uint32
155 enum: [ 0, 1 ]
156 description:
157 Active state of Sync-on-green (SoG) signal, 0/1 for LOW/HIGH respectively.
158
159 data-lanes:
160 $ref: /schemas/types.yaml#/definitions/uint32-array
161 minItems: 1
162 maxItems: 8
163 uniqueItems: true
164 items:
165 # Assume up to 9 physical lane indices
166 maximum: 8
167 description:
168 An array of physical data lane indexes. Position of an entry determines
169 the logical lane number, while the value of an entry indicates physical
170 lane, e.g. for 2-lane MIPI CSI-2 bus we could have "data-lanes = <1 2>;",
171 assuming the clock lane is on hardware lane 0. If the hardware does not
172 support lane reordering, monotonically incremented values shall be used
173 from 0 or 1 onwards, depending on whether or not there is also a clock
174 lane. This property is valid for serial busses only (e.g. MIPI CSI-2).
175
176 clock-lanes:
177 $ref: /schemas/types.yaml#/definitions/uint32
178 # Assume up to 9 physical lane indices
179 maximum: 8
180 description:
181 Physical clock lane index. Position of an entry determines the logical
182 lane number, while the value of an entry indicates physical lane, e.g. for
183 a MIPI CSI-2 bus we could have "clock-lanes = <0>;", which places the
184 clock lane on hardware lane 0. This property is valid for serial busses
185 only (e.g. MIPI CSI-2).
186
187 clock-noncontinuous:
188 type: boolean
189 description:
190 Allow MIPI CSI-2 non-continuous clock mode.
191
192 link-frequencies:
193 $ref: /schemas/types.yaml#/definitions/uint64-array
194 description:
195 Allowed data bus frequencies. For MIPI CSI-2, for instance, this is the
196 actual frequency of the bus, not bits per clock per lane value. An array
197 of 64-bit unsigned integers.
198
199 lane-polarities:
200 $ref: /schemas/types.yaml#/definitions/uint32-array
201 minItems: 1
202 maxItems: 9
203 items:
204 enum: [ 0, 1 ]
205 description:
206 An array of polarities of the lanes starting from the clock lane and
207 followed by the data lanes in the same order as in data-lanes. Valid
208 values are 0 (normal) and 1 (inverted). The length of the array should be
209 the combined length of data-lanes and clock-lanes properties. If the
210 lane-polarities property is omitted, the value must be interpreted as 0
211 (normal). This property is valid for serial busses only.
212
213 strobe:
214 $ref: /schemas/types.yaml#/definitions/uint32
215 enum: [ 0, 1 ]
216 description:
217 Whether the clock signal is used as clock (0) or strobe (1). Used with
218 CCP2, for instance.
219
220 additionalProperties: true
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