0001 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
0002 %YAML 1.2
0003 ---
0004 $id: http://devicetree.org/schemas/media/video-interfaces.yaml#
0005 $schema: http://devicetree.org/meta-schemas/core.yaml#
0006
0007 title: Common bindings for video receiver and transmitter interface endpoints
0008
0009 maintainers:
0010 - Sakari Ailus <sakari.ailus@linux.intel.com>
0011 - Laurent Pinchart <laurent.pinchart@ideasonboard.com>
0012
0013 description: |
0014 Video data pipelines usually consist of external devices, e.g. camera sensors,
0015 controlled over an I2C, SPI or UART bus, and SoC internal IP blocks, including
0016 video DMA engines and video data processors.
0017
0018 SoC internal blocks are described by DT nodes, placed similarly to other SoC
0019 blocks. External devices are represented as child nodes of their respective
0020 bus controller nodes, e.g. I2C.
0021
0022 Data interfaces on all video devices are described by their child 'port' nodes.
0023 Configuration of a port depends on other devices participating in the data
0024 transfer and is described by 'endpoint' subnodes.
0025
0026 device {
0027 ...
0028 ports {
0029 #address-cells = <1>;
0030 #size-cells = <0>;
0031
0032 port@0 {
0033 ...
0034 endpoint@0 { ... };
0035 endpoint@1 { ... };
0036 };
0037 port@1 { ... };
0038 };
0039 };
0040
0041 If a port can be configured to work with more than one remote device on the same
0042 bus, an 'endpoint' child node must be provided for each of them. If more than
0043 one port is present in a device node or there is more than one endpoint at a
0044 port, or port node needs to be associated with a selected hardware interface,
0045 a common scheme using '#address-cells', '#size-cells' and 'reg' properties is
0046 used.
0047
0048 All 'port' nodes can be grouped under optional 'ports' node, which allows to
0049 specify #address-cells, #size-cells properties independently for the 'port'
0050 and 'endpoint' nodes and any child device nodes a device might have.
0051
0052 Two 'endpoint' nodes are linked with each other through their 'remote-endpoint'
0053 phandles. An endpoint subnode of a device contains all properties needed for
0054 configuration of this device for data exchange with other device. In most
0055 cases properties at the peer 'endpoint' nodes will be identical, however they
0056 might need to be different when there is any signal modifications on the bus
0057 between two devices, e.g. there are logic signal inverters on the lines.
0058
0059 It is allowed for multiple endpoints at a port to be active simultaneously,
0060 where supported by a device. For example, in case where a data interface of
0061 a device is partitioned into multiple data busses, e.g. 16-bit input port
0062 divided into two separate ITU-R BT.656 8-bit busses. In such case bus-width
0063 and data-shift properties can be used to assign physical data lines to each
0064 endpoint node (logical bus).
0065
0066 Documenting bindings for devices
0067 --------------------------------
0068
0069 All required and optional bindings the device supports shall be explicitly
0070 documented in device DT binding documentation. This also includes port and
0071 endpoint nodes for the device, including unit-addresses and reg properties
0072 where relevant.
0073
0074 allOf:
0075 - $ref: /schemas/graph.yaml#/$defs/endpoint-base
0076
0077 properties:
0078 slave-mode:
0079 type: boolean
0080 description:
0081 Indicates that the link is run in slave mode. The default when this
0082 property is not specified is master mode. In the slave mode horizontal and
0083 vertical synchronization signals are provided to the slave device (data
0084 source) by the master device (data sink). In the master mode the data
0085 source device is also the source of the synchronization signals.
0086
0087 bus-type:
0088 $ref: /schemas/types.yaml#/definitions/uint32
0089 enum:
0090 - 1 # MIPI CSI-2 C-PHY
0091 - 2 # MIPI CSI1
0092 - 3 # CCP2
0093 - 4 # MIPI CSI-2 D-PHY
0094 - 5 # Parallel
0095 - 6 # BT.656
0096 - 7 # DPI
0097 description:
0098 Data bus type.
0099
0100 bus-width:
0101 $ref: /schemas/types.yaml#/definitions/uint32
0102 maximum: 64
0103 description:
0104 Number of data lines actively used, valid for the parallel busses.
0105
0106 data-shift:
0107 $ref: /schemas/types.yaml#/definitions/uint32
0108 maximum: 64
0109 description:
0110 On the parallel data busses, if bus-width is used to specify the number of
0111 data lines, data-shift can be used to specify which data lines are used,
0112 e.g. "bus-width=<8>; data-shift=<2>;" means, that lines 9:2 are used.
0113
0114 hsync-active:
0115 $ref: /schemas/types.yaml#/definitions/uint32
0116 enum: [ 0, 1 ]
0117 description:
0118 Active state of the HSYNC signal, 0/1 for LOW/HIGH respectively.
0119
0120 vsync-active:
0121 $ref: /schemas/types.yaml#/definitions/uint32
0122 enum: [ 0, 1 ]
0123 description:
0124 Active state of the VSYNC signal, 0/1 for LOW/HIGH respectively. Note,
0125 that if HSYNC and VSYNC polarities are not specified, embedded
0126 synchronization may be required, where supported.
0127
0128 data-active:
0129 $ref: /schemas/types.yaml#/definitions/uint32
0130 enum: [ 0, 1 ]
0131 description:
0132 Similar to HSYNC and VSYNC, specifies data line polarity.
0133
0134 data-enable-active:
0135 $ref: /schemas/types.yaml#/definitions/uint32
0136 enum: [ 0, 1 ]
0137 description:
0138 Similar to HSYNC and VSYNC, specifies the data enable signal polarity.
0139
0140 field-even-active:
0141 $ref: /schemas/types.yaml#/definitions/uint32
0142 enum: [ 0, 1 ]
0143 description:
0144 Field signal level during the even field data transmission.
0145
0146 pclk-sample:
0147 $ref: /schemas/types.yaml#/definitions/uint32
0148 enum: [ 0, 1 ]
0149 description:
0150 Sample data on rising (1) or falling (0) edge of the pixel clock signal.
0151
0152 sync-on-green-active:
0153 $ref: /schemas/types.yaml#/definitions/uint32
0154 enum: [ 0, 1 ]
0155 description:
0156 Active state of Sync-on-green (SoG) signal, 0/1 for LOW/HIGH respectively.
0157
0158 data-lanes:
0159 $ref: /schemas/types.yaml#/definitions/uint32-array
0160 minItems: 1
0161 maxItems: 8
0162 items:
0163 # Assume up to 9 physical lane indices
0164 maximum: 8
0165 description:
0166 An array of physical data lane indexes. Position of an entry determines
0167 the logical lane number, while the value of an entry indicates physical
0168 lane, e.g. for 2-lane MIPI CSI-2 bus we could have "data-lanes = <1 2>;",
0169 assuming the clock lane is on hardware lane 0. If the hardware does not
0170 support lane reordering, monotonically incremented values shall be used
0171 from 0 or 1 onwards, depending on whether or not there is also a clock
0172 lane. This property is valid for serial busses only (e.g. MIPI CSI-2).
0173
0174 clock-lanes:
0175 $ref: /schemas/types.yaml#/definitions/uint32
0176 # Assume up to 9 physical lane indices
0177 maximum: 8
0178 description:
0179 Physical clock lane index. Position of an entry determines the logical
0180 lane number, while the value of an entry indicates physical lane, e.g. for
0181 a MIPI CSI-2 bus we could have "clock-lanes = <0>;", which places the
0182 clock lane on hardware lane 0. This property is valid for serial busses
0183 only (e.g. MIPI CSI-2).
0184
0185 clock-noncontinuous:
0186 type: boolean
0187 description:
0188 Allow MIPI CSI-2 non-continuous clock mode.
0189
0190 link-frequencies:
0191 $ref: /schemas/types.yaml#/definitions/uint64-array
0192 description:
0193 Allowed data bus frequencies. For MIPI CSI-2, for instance, this is the
0194 actual frequency of the bus, not bits per clock per lane value. An array
0195 of 64-bit unsigned integers.
0196
0197 lane-polarities:
0198 $ref: /schemas/types.yaml#/definitions/uint32-array
0199 minItems: 1
0200 maxItems: 9
0201 items:
0202 enum: [ 0, 1 ]
0203 description:
0204 An array of polarities of the lanes starting from the clock lane and
0205 followed by the data lanes in the same order as in data-lanes. Valid
0206 values are 0 (normal) and 1 (inverted). The length of the array should be
0207 the combined length of data-lanes and clock-lanes properties. If the
0208 lane-polarities property is omitted, the value must be interpreted as 0
0209 (normal). This property is valid for serial busses only.
0210
0211 strobe:
0212 $ref: /schemas/types.yaml#/definitions/uint32
0213 enum: [ 0, 1 ]
0214 description:
0215 Whether the clock signal is used as clock (0) or strobe (1). Used with
0216 CCP2, for instance.
0217
0218 additionalProperties: true
