2.23. V4L2 fwnode kAPI¶

struct v4l2_fwnode_endpoint¶: the endpoint data structure

Definition:

struct v4l2_fwnode_endpoint {
    struct fwnode_endpoint base;
    enum v4l2_mbus_type bus_type;
    struct {
        struct v4l2_mbus_config_parallel parallel;
        struct v4l2_mbus_config_mipi_csi1 mipi_csi1;
        struct v4l2_mbus_config_mipi_csi2 mipi_csi2;
    } bus;
    u64 *link_frequencies;
    unsigned int nr_of_link_frequencies;
};

Members

base: fwnode endpoint of the v4l2_fwnode
bus_type: bus type
bus: bus configuration data structure
bus.parallel: embedded struct v4l2_mbus_config_parallel. Used if the bus is parallel.
bus.mipi_csi1: embedded struct v4l2_mbus_config_mipi_csi1. Used if the bus is MIPI Alliance’s Camera Serial Interface version 1 (MIPI CSI1) or Standard Mobile Imaging Architecture’s Compact Camera Port 2 (SMIA CCP2).
bus.mipi_csi2: embedded struct v4l2_mbus_config_mipi_csi2. Used if the bus is MIPI Alliance’s Camera Serial Interface version 2 (MIPI CSI2).
link_frequencies: array of supported link frequencies
nr_of_link_frequencies: number of elements in link_frequenccies array

V4L2_FWNODE_PROPERTY_UNSET¶

V4L2_FWNODE_PROPERTY_UNSET ()

identify a non initialized property

Parameters

Description

All properties in struct v4l2_fwnode_device_properties are initialized to this value.

enum v4l2_fwnode_orientation¶: possible device orientation

Constants

V4L2_FWNODE_ORIENTATION_FRONT: device installed on the front side
V4L2_FWNODE_ORIENTATION_BACK: device installed on the back side
V4L2_FWNODE_ORIENTATION_EXTERNAL: device externally located

struct v4l2_fwnode_device_properties¶: fwnode device properties

Definition:

struct v4l2_fwnode_device_properties {
    enum v4l2_fwnode_orientation orientation;
    unsigned int rotation;
};

Members

orientation: device orientation. See enum v4l2_fwnode_orientation
rotation: device rotation

struct v4l2_fwnode_link¶: a link between two endpoints

Definition:

struct v4l2_fwnode_link {
    struct fwnode_handle *local_node;
    unsigned int local_port;
    unsigned int local_id;
    struct fwnode_handle *remote_node;
    unsigned int remote_port;
    unsigned int remote_id;
};

Members

local_node: pointer to device_node of this endpoint
local_port: identifier of the port this endpoint belongs to
local_id: identifier of the id this endpoint belongs to
remote_node: pointer to device_node of the remote endpoint
remote_port: identifier of the port the remote endpoint belongs to
remote_id: identifier of the id the remote endpoint belongs to

enum v4l2_connector_type¶: connector type

Constants

V4L2_CONN_UNKNOWN: unknown connector type, no V4L2 connector configuration
V4L2_CONN_COMPOSITE: analog composite connector
V4L2_CONN_SVIDEO: analog svideo connector

struct v4l2_connector_link¶: connector link data structure

Definition:

struct v4l2_connector_link {
    struct list_head head;
    struct v4l2_fwnode_link fwnode_link;
};

Members

head: structure to be used to add the link to the struct v4l2_fwnode_connector
fwnode_link: struct v4l2_fwnode_link link between the connector and the device the connector belongs to.

struct v4l2_fwnode_connector_analog¶: analog connector data structure

Definition:

struct v4l2_fwnode_connector_analog {
    v4l2_std_id sdtv_stds;
};

Members

sdtv_stds: sdtv standards this connector supports, set to V4L2_STD_ALL if no restrictions are specified.

struct v4l2_fwnode_connector¶: the connector data structure

Definition:

struct v4l2_fwnode_connector {
    const char *name;
    const char *label;
    enum v4l2_connector_type type;
    struct list_head links;
    unsigned int nr_of_links;
    union {
        struct v4l2_fwnode_connector_analog analog;
    } connector;
};

Members

name: the connector device name
label: optional connector label
type: connector type
links: list of all connector struct v4l2_connector_link links
nr_of_links: total number of links
connector: connector configuration
connector.analog: analog connector configuration struct v4l2_fwnode_connector_analog

enum v4l2_fwnode_bus_type¶: Video bus types defined by firmware properties

Constants

V4L2_FWNODE_BUS_TYPE_GUESS: Default value if no bus-type fwnode property
V4L2_FWNODE_BUS_TYPE_CSI2_CPHY: MIPI CSI-2 bus, C-PHY physical layer
V4L2_FWNODE_BUS_TYPE_CSI1: MIPI CSI-1 bus
V4L2_FWNODE_BUS_TYPE_CCP2: SMIA Compact Camera Port 2 bus
V4L2_FWNODE_BUS_TYPE_CSI2_DPHY: MIPI CSI-2 bus, D-PHY physical layer
V4L2_FWNODE_BUS_TYPE_PARALLEL: Camera Parallel Interface bus
V4L2_FWNODE_BUS_TYPE_BT656: BT.656 video format bus-type
V4L2_FWNODE_BUS_TYPE_DPI: Video Parallel Interface bus
NR_OF_V4L2_FWNODE_BUS_TYPE: Number of bus-types

int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode, struct v4l2_fwnode_endpoint *vep)¶: parse all fwnode node properties

Parameters

struct fwnode_handle *fwnode: pointer to the endpoint’s fwnode handle
struct v4l2_fwnode_endpoint *vep: pointer to the V4L2 fwnode data structure

Description

This function parses the V4L2 fwnode endpoint specific parameters from the firmware. There are two ways to use this function, either by letting it obtain the type of the bus (by setting the vep.bus_type field to V4L2_MBUS_UNKNOWN) or specifying the bus type explicitly to one of the enum v4l2_mbus_type types.

When vep.bus_type is V4L2_MBUS_UNKNOWN, the function will use the “bus-type” property to determine the type when it is available. The caller is responsible for validating the contents of vep.bus_type field after the call returns.

As a deprecated functionality to support older DT bindings without “bus-type” property for devices that support multiple types, if the “bus-type” property does not exist, the function will attempt to guess the type based on the endpoint properties available. NEVER RELY ON GUESSING THE BUS TYPE IN NEW DRIVERS OR BINDINGS.

It is also possible to set vep.bus_type corresponding to an actual bus. In this case the function will only attempt to parse properties related to this bus, and it will return an error if the value of the “bus-type” property corresponds to a different bus.

The caller is required to initialise all fields of vep, either with explicitly values, or by zeroing them.

The function does not change the V4L2 fwnode endpoint state if it fails.

NOTE

This function does not parse “link-frequencies” property as its size is not known in advance. Please use v4l2_fwnode_endpoint_alloc_parse() if you need properties of variable size.

Return

0 on success or a negative error code on failure:: -ENOMEM on memory allocation failure -EINVAL on parsing failure -ENXIO on mismatching bus types

void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep)¶: free the V4L2 fwnode acquired by v4l2_fwnode_endpoint_alloc_parse()

Parameters

struct v4l2_fwnode_endpoint *vep: the V4L2 fwnode the resources of which are to be released

Description

It is safe to call this function with NULL argument or on a V4L2 fwnode the parsing of which failed.

int v4l2_fwnode_endpoint_alloc_parse(struct fwnode_handle *fwnode, struct v4l2_fwnode_endpoint *vep)¶: parse all fwnode node properties

Parameters

struct fwnode_handle *fwnode: pointer to the endpoint’s fwnode handle
struct v4l2_fwnode_endpoint *vep: pointer to the V4L2 fwnode data structure

Description

This function parses the V4L2 fwnode endpoint specific parameters from the firmware. There are two ways to use this function, either by letting it obtain the type of the bus (by setting the vep.bus_type field to V4L2_MBUS_UNKNOWN) or specifying the bus type explicitly to one of the enum v4l2_mbus_type types.

When vep.bus_type is V4L2_MBUS_UNKNOWN, the function will use the “bus-type” property to determine the type when it is available. The caller is responsible for validating the contents of vep.bus_type field after the call returns.

As a deprecated functionality to support older DT bindings without “bus-type” property for devices that support multiple types, if the “bus-type” property does not exist, the function will attempt to guess the type based on the endpoint properties available. NEVER RELY ON GUESSING THE BUS TYPE IN NEW DRIVERS OR BINDINGS.

It is also possible to set vep.bus_type corresponding to an actual bus. In this case the function will only attempt to parse properties related to this bus, and it will return an error if the value of the “bus-type” property corresponds to a different bus.

The caller is required to initialise all fields of vep, either with explicitly values, or by zeroing them.

The function does not change the V4L2 fwnode endpoint state if it fails.

v4l2_fwnode_endpoint_alloc_parse() has two important differences to v4l2_fwnode_endpoint_parse():

It also parses variable size data.
The memory it has allocated to store the variable size data must be freed using v4l2_fwnode_endpoint_free() when no longer needed.

Return

0 on success or a negative error code on failure:: -ENOMEM on memory allocation failure -EINVAL on parsing failure -ENXIO on mismatching bus types

int v4l2_fwnode_parse_link(struct fwnode_handle *fwnode, struct v4l2_fwnode_link *link)¶: parse a link between two endpoints

Parameters

struct fwnode_handle *fwnode: pointer to the endpoint’s fwnode at the local end of the link
struct v4l2_fwnode_link *link: pointer to the V4L2 fwnode link data structure

Description

Fill the link structure with the local and remote nodes and port numbers. The local_node and remote_node fields are set to point to the local and remote port’s parent nodes respectively (the port parent node being the parent node of the port node if that node isn’t a ‘ports’ node, or the grand-parent node of the port node otherwise).

A reference is taken to both the local and remote nodes, the caller must use v4l2_fwnode_put_link() to drop the references when done with the link.

Return

0 on success, or -ENOLINK if the remote endpoint fwnode can’t be found.

void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link)¶: drop references to nodes in a link

Parameters

struct v4l2_fwnode_link *link: pointer to the V4L2 fwnode link data structure

Description

Drop references to the local and remote nodes in the link. This function must be called on every link parsed with v4l2_fwnode_parse_link().

void v4l2_fwnode_connector_free(struct v4l2_fwnode_connector *connector)¶: free the V4L2 connector acquired memory

Parameters

struct v4l2_fwnode_connector *connector: the V4L2 connector resources of which are to be released

Description

Free all allocated memory and put all links acquired by v4l2_fwnode_connector_parse() and v4l2_fwnode_connector_add_link().

It is safe to call this function with NULL argument or on a V4L2 connector the parsing of which failed.

int v4l2_fwnode_connector_parse(struct fwnode_handle *fwnode, struct v4l2_fwnode_connector *connector)¶: initialize the ‘struct v4l2_fwnode_connector’

Parameters

struct fwnode_handle *fwnode: pointer to the subdev endpoint’s fwnode handle where the connector is connected to or to the connector endpoint fwnode handle.
struct v4l2_fwnode_connector *connector: pointer to the V4L2 fwnode connector data structure

Description

Fill the struct v4l2_fwnode_connector with the connector type, label and all enum v4l2_connector_type specific connector data. The label is optional so it is set to NULL if no one was found. The function initialize the links to zero. Adding links to the connector is done by calling v4l2_fwnode_connector_add_link().

The memory allocated for the label must be freed when no longer needed. Freeing the memory is done by v4l2_fwnode_connector_free().

Return

0 on success or a negative error code on failure:
-EINVAL if fwnode is invalid
-ENOTCONN if connector type is unknown or connector device can’t be found

int v4l2_fwnode_connector_add_link(struct fwnode_handle *fwnode, struct v4l2_fwnode_connector *connector)¶: add a link between a connector node and a v4l2-subdev node.

Parameters

struct fwnode_handle *fwnode: pointer to the subdev endpoint’s fwnode handle where the connector is connected to
struct v4l2_fwnode_connector *connector: pointer to the V4L2 fwnode connector data structure

Description

Add a new struct v4l2_connector_link link to the struct v4l2_fwnode_connector connector links list. The link local_node points to the connector node, the remote_node to the host v4l2 (sub)dev.

The taken references to remote_node and local_node must be dropped and the allocated memory must be freed when no longer needed. Both is done by calling v4l2_fwnode_connector_free().

Return

0 on success or a negative error code on failure:
-EINVAL if fwnode or connector is invalid or connector type is unknown
-ENOMEM on link memory allocation failure
-ENOTCONN if remote connector device can’t be found
-ENOLINK if link parsing between v4l2 (sub)dev and connector fails

int v4l2_fwnode_device_parse(struct device *dev, struct v4l2_fwnode_device_properties *props)¶: parse fwnode device properties

Parameters

struct device *dev: pointer to struct device
struct v4l2_fwnode_device_properties *props: pointer to struct v4l2_fwnode_device_properties where to store the parsed properties values

Description

This function parses and validates the V4L2 fwnode device properties from the firmware interface, and fills the struct v4l2_fwnode_device_properties provided by the caller.

Return

% 0 on success -EINVAL if a parsed property value is not valid

The Linux Kernel

Contents

This Page

2.23. V4L2 fwnode kAPI¶