| # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) |
| %YAML 1.2 |
| --- |
| $id: http://devicetree.org/schemas/media/video-interfaces.yaml# |
| $schema: http://devicetree.org/meta-schemas/core.yaml# |
| |
| title: Common Properties for Video Receiver and Transmitter Interface Endpoints |
| |
| maintainers: |
| - Sakari Ailus <sakari.ailus@linux.intel.com> |
| - Laurent Pinchart <laurent.pinchart@ideasonboard.com> |
| |
| description: | |
| Video data pipelines usually consist of external devices, e.g. camera sensors, |
| controlled over an I2C, SPI or UART bus, and SoC internal IP blocks, including |
| video DMA engines and video data processors. |
| |
| SoC internal blocks are described by DT nodes, placed similarly to other SoC |
| blocks. External devices are represented as child nodes of their respective |
| bus controller nodes, e.g. I2C. |
| |
| Data interfaces on all video devices are described by their child 'port' nodes. |
| Configuration of a port depends on other devices participating in the data |
| transfer and is described by 'endpoint' subnodes. |
| |
| device { |
| ... |
| ports { |
| #address-cells = <1>; |
| #size-cells = <0>; |
| |
| port@0 { |
| ... |
| endpoint@0 { ... }; |
| endpoint@1 { ... }; |
| }; |
| port@1 { ... }; |
| }; |
| }; |
| |
| If a port can be configured to work with more than one remote device on the same |
| bus, an 'endpoint' child node must be provided for each of them. If more than |
| one port is present in a device node or there is more than one endpoint at a |
| port, or port node needs to be associated with a selected hardware interface, |
| a common scheme using '#address-cells', '#size-cells' and 'reg' properties is |
| used. |
| |
| All 'port' nodes can be grouped under optional 'ports' node, which allows to |
| specify #address-cells, #size-cells properties independently for the 'port' |
| and 'endpoint' nodes and any child device nodes a device might have. |
| |
| Two 'endpoint' nodes are linked with each other through their 'remote-endpoint' |
| phandles. An endpoint subnode of a device contains all properties needed for |
| configuration of this device for data exchange with other device. In most |
| cases properties at the peer 'endpoint' nodes will be identical, however they |
| might need to be different when there is any signal modifications on the bus |
| between two devices, e.g. there are logic signal inverters on the lines. |
| |
| It is allowed for multiple endpoints at a port to be active simultaneously, |
| where supported by a device. For example, in case where a data interface of |
| a device is partitioned into multiple data busses, e.g. 16-bit input port |
| divided into two separate ITU-R BT.656 8-bit busses. In such case bus-width |
| and data-shift properties can be used to assign physical data lines to each |
| endpoint node (logical bus). |
| |
| Documenting bindings for devices |
| -------------------------------- |
| |
| All required and optional bindings the device supports shall be explicitly |
| documented in device DT binding documentation. This also includes port and |
| endpoint nodes for the device, including unit-addresses and reg properties |
| where relevant. |
| |
| allOf: |
| - $ref: /schemas/graph.yaml#/$defs/endpoint-base |
| |
| properties: |
| slave-mode: |
| type: boolean |
| description: |
| Indicates that the link is run in slave mode. The default when this |
| property is not specified is master mode. In the slave mode horizontal and |
| vertical synchronization signals are provided to the slave device (data |
| source) by the master device (data sink). In the master mode the data |
| source device is also the source of the synchronization signals. |
| |
| bus-type: |
| $ref: /schemas/types.yaml#/definitions/uint32 |
| enum: |
| - 1 # MIPI CSI-2 C-PHY |
| - 2 # MIPI CSI1 |
| - 3 # CCP2 |
| - 4 # MIPI CSI-2 D-PHY |
| - 5 # Parallel |
| - 6 # BT.656 |
| - 7 # DPI |
| description: |
| Data bus type. |
| |
| bus-width: |
| $ref: /schemas/types.yaml#/definitions/uint32 |
| maximum: 64 |
| description: |
| Number of data lines actively used, valid for the parallel busses. |
| |
| data-shift: |
| $ref: /schemas/types.yaml#/definitions/uint32 |
| maximum: 64 |
| description: |
| On the parallel data busses, if bus-width is used to specify the number of |
| data lines, data-shift can be used to specify which data lines are used, |
| e.g. "bus-width=<8>; data-shift=<2>;" means, that lines 9:2 are used. |
| |
| hsync-active: |
| $ref: /schemas/types.yaml#/definitions/uint32 |
| enum: [ 0, 1 ] |
| description: |
| Active state of the HSYNC signal, 0/1 for LOW/HIGH respectively. |
| |
| vsync-active: |
| $ref: /schemas/types.yaml#/definitions/uint32 |
| enum: [ 0, 1 ] |
| description: |
| Active state of the VSYNC signal, 0/1 for LOW/HIGH respectively. Note, |
| that if HSYNC and VSYNC polarities are not specified, embedded |
| synchronization may be required, where supported. |
| |
| data-active: |
| $ref: /schemas/types.yaml#/definitions/uint32 |
| enum: [ 0, 1 ] |
| description: |
| Similar to HSYNC and VSYNC, specifies data line polarity. |
| |
| data-enable-active: |
| $ref: /schemas/types.yaml#/definitions/uint32 |
| enum: [ 0, 1 ] |
| description: |
| Similar to HSYNC and VSYNC, specifies the data enable signal polarity. |
| |
| field-even-active: |
| $ref: /schemas/types.yaml#/definitions/uint32 |
| enum: [ 0, 1 ] |
| description: |
| Field signal level during the even field data transmission. |
| |
| pclk-sample: |
| $ref: /schemas/types.yaml#/definitions/uint32 |
| enum: [ 0, 1, 2 ] |
| description: |
| Sample data on falling (0), rising (1) or both (2) edges of the pixel |
| clock signal. |
| |
| sync-on-green-active: |
| $ref: /schemas/types.yaml#/definitions/uint32 |
| enum: [ 0, 1 ] |
| description: |
| Active state of Sync-on-green (SoG) signal, 0/1 for LOW/HIGH respectively. |
| |
| data-lanes: |
| $ref: /schemas/types.yaml#/definitions/uint32-array |
| minItems: 1 |
| maxItems: 8 |
| items: |
| # Assume up to 9 physical lane indices |
| maximum: 8 |
| description: |
| An array of physical data lane indexes. Position of an entry determines |
| the logical lane number, while the value of an entry indicates physical |
| lane, e.g. for 2-lane MIPI CSI-2 bus we could have "data-lanes = <1 2>;", |
| assuming the clock lane is on hardware lane 0. If the hardware does not |
| support lane reordering, monotonically incremented values shall be used |
| from 0 or 1 onwards, depending on whether or not there is also a clock |
| lane. This property is valid for serial busses only (e.g. MIPI CSI-2). |
| |
| clock-lanes: |
| $ref: /schemas/types.yaml#/definitions/uint32 |
| # Assume up to 9 physical lane indices |
| maximum: 8 |
| description: |
| Physical clock lane index. Position of an entry determines the logical |
| lane number, while the value of an entry indicates physical lane, e.g. for |
| a MIPI CSI-2 bus we could have "clock-lanes = <0>;", which places the |
| clock lane on hardware lane 0. This property is valid for serial busses |
| only (e.g. MIPI CSI-2). |
| |
| clock-noncontinuous: |
| type: boolean |
| description: |
| Allow MIPI CSI-2 non-continuous clock mode. |
| |
| link-frequencies: |
| $ref: /schemas/types.yaml#/definitions/uint64-array |
| description: |
| Allowed data bus frequencies. For MIPI CSI-2, for instance, this is the |
| actual frequency of the bus, not bits per clock per lane value. An array |
| of 64-bit unsigned integers. |
| |
| lane-polarities: |
| $ref: /schemas/types.yaml#/definitions/uint32-array |
| minItems: 1 |
| maxItems: 9 |
| items: |
| enum: [ 0, 1 ] |
| description: |
| An array of polarities of the lanes starting from the clock lane and |
| followed by the data lanes in the same order as in data-lanes. Valid |
| values are 0 (normal) and 1 (inverted). The length of the array should be |
| the combined length of data-lanes and clock-lanes properties. If the |
| lane-polarities property is omitted, the value must be interpreted as 0 |
| (normal). This property is valid for serial busses only. |
| |
| strobe: |
| $ref: /schemas/types.yaml#/definitions/uint32 |
| enum: [ 0, 1 ] |
| description: |
| Whether the clock signal is used as clock (0) or strobe (1). Used with |
| CCP2, for instance. |
| |
| additionalProperties: true |