1.22. V4L2 fwnode kAPI¶

struct v4l2_fwnode_bus_mipi_csi2: MIPI CSI-2 bus data structure

Definition

struct v4l2_fwnode_bus_mipi_csi2 {
  unsigned int flags;
  unsigned char data_lanes[V4L2_FWNODE_CSI2_MAX_DATA_LANES];
  unsigned char clock_lane;
  unsigned short num_data_lanes;
  bool lane_polarities[1 + V4L2_FWNODE_CSI2_MAX_DATA_LANES];
};

Members

flags: media bus (V4L2_MBUS_*) flags
data_lanes: an array of physical data lane indexes
clock_lane: physical lane index of the clock lane
num_data_lanes: number of data lanes
lane_polarities: polarity of the lanes. The order is the same of the physical lanes.

struct v4l2_fwnode_bus_parallel: parallel data bus data structure

Definition

struct v4l2_fwnode_bus_parallel {
  unsigned int flags;
  unsigned char bus_width;
  unsigned char data_shift;
};

Members

flags: media bus (V4L2_MBUS_*) flags
bus_width: bus width in bits
data_shift: data shift in bits

struct v4l2_fwnode_bus_mipi_csi1: CSI-1/CCP2 data bus structure

Definition

struct v4l2_fwnode_bus_mipi_csi1 {
  unsigned char clock_inv:1;
  unsigned char strobe:1;
  bool lane_polarity[2];
  unsigned char data_lane;
  unsigned char clock_lane;
};

Members

clock_inv: polarity of clock/strobe signal false - not inverted, true - inverted
strobe: false - data/clock, true - data/strobe
lane_polarity: the polarities of the clock (index 0) and data lanes index (1)
data_lane: the number of the data lane
clock_lane: the number of the clock lane

struct v4l2_fwnode_endpoint: the endpoint data structure

Definition

struct v4l2_fwnode_endpoint {
  struct fwnode_endpoint base;
  enum v4l2_mbus_type bus_type;
  union {
    struct v4l2_fwnode_bus_parallel parallel;
    struct v4l2_fwnode_bus_mipi_csi1 mipi_csi1;
    struct v4l2_fwnode_bus_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: union with bus configuration data structure
bus.parallel: embedded struct v4l2_fwnode_bus_parallel. Used if the bus is parallel.
bus.mipi_csi1: embedded struct v4l2_fwnode_bus_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_fwnode_bus_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

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

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. The caller is responsible for assigning vep.bus_type to a valid media bus type. The caller may also set the default configuration for the endpoint — a configuration that shall be in line with the DT binding documentation. Should a device support multiple bus types, the caller may call this function once the correct type is found — with a default configuration valid for that type.

As a compatibility means guessing the bus type is also supported by setting vep.bus_type to V4L2_MBUS_UNKNOWN. The caller may not provide a default configuration in this case as the defaults are specific to a given bus type. This functionality is deprecated and should not be used in new drivers and it is only supported for CSI-2 D-PHY, parallel and Bt.656 buses.

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

NOTE

This function does not parse properties the size of which is variable without a low fixed limit. Please use v4l2_fwnode_endpoint_alloc_parse() in new drivers instead.

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. The caller is responsible for assigning vep.bus_type to a valid media bus type. The caller may also set the default configuration for the endpoint — a configuration that shall be in line with the DT binding documentation. Should a device support multiple bus types, the caller may call this function once the correct type is found — with a default configuration valid for that type.

As a compatibility means guessing the bus type is also supported by setting vep.bus_type to V4L2_MBUS_UNKNOWN. The caller may not provide a default configuration in this case as the defaults are specific to a given bus type. This functionality is deprecated and should not be used in new drivers and it is only supported for CSI-2 D-PHY, parallel and Bt.656 buses.

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

type parse_endpoint_func¶: Typedef: Driver’s callback function to be called on each V4L2 fwnode endpoint.

Syntax

int parse_endpoint_func (struct device * dev, struct v4l2_fwnode_endpoint * vep, struct v4l2_async_subdev * asd);

Parameters

struct device * dev: pointer to struct device
struct v4l2_fwnode_endpoint * vep: pointer to struct v4l2_fwnode_endpoint
struct v4l2_async_subdev * asd: pointer to struct v4l2_async_subdev

Return

0 on success
-ENOTCONN if the endpoint is to be skipped but this should not be considered as an error
-EINVAL if the endpoint configuration is invalid

int v4l2_async_notifier_parse_fwnode_endpoints(struct device *dev, struct v4l2_async_notifier *notifier, size_t asd_struct_size, parse_endpoint_func parse_endpoint)¶: Parse V4L2 fwnode endpoints in a device node

Parameters

struct device * dev: the device the endpoints of which are to be parsed
struct v4l2_async_notifier * notifier: notifier for dev
size_t asd_struct_size: size of the driver’s async sub-device struct, including sizeof(struct v4l2_async_subdev). The struct v4l2_async_subdev shall be the first member of the driver’s async sub-device struct, i.e. both begin at the same memory address.
parse_endpoint_func parse_endpoint: Driver’s callback function called on each V4L2 fwnode endpoint. Optional.

Description

Parse the fwnode endpoints of the dev device and populate the async sub- devices list in the notifier. The parse_endpoint callback function is called for each endpoint with the corresponding async sub-device pointer to let the caller initialize the driver-specific part of the async sub-device structure.

The notifier memory shall be zeroed before this function is called on the notifier.

This function may not be called on a registered notifier and may be called on a notifier only once.

The struct v4l2_fwnode_endpoint passed to the callback function parse_endpoint is released once the function is finished. If there is a need to retain that configuration, the user needs to allocate memory for it.

Any notifier populated using this function must be released with a call to v4l2_async_notifier_cleanup() after it has been unregistered and the async sub-devices are no longer in use, even if the function returned an error.

Return

0 on success, including when no async sub-devices are found: -ENOMEM if memory allocation failed -EINVAL if graph or endpoint parsing failed Other error codes as returned by parse_endpoint

int v4l2_async_notifier_parse_fwnode_endpoints_by_port(struct device *dev, struct v4l2_async_notifier *notifier, size_t asd_struct_size, unsigned int port, parse_endpoint_func parse_endpoint)¶: Parse V4L2 fwnode endpoints of a port in a device node

Parameters

struct device * dev: the device the endpoints of which are to be parsed
struct v4l2_async_notifier * notifier: notifier for dev
size_t asd_struct_size: size of the driver’s async sub-device struct, including sizeof(struct v4l2_async_subdev). The struct v4l2_async_subdev shall be the first member of the driver’s async sub-device struct, i.e. both begin at the same memory address.
unsigned int port: port number where endpoints are to be parsed
parse_endpoint_func parse_endpoint: Driver’s callback function called on each V4L2 fwnode endpoint. Optional.

Description

This function is just like v4l2_async_notifier_parse_fwnode_endpoints() with the exception that it only parses endpoints in a given port. This is useful on devices that have both sinks and sources: the async sub-devices connected to sources have already been configured by another driver (on capture devices). In this case the driver must know which ports to parse.

Parse the fwnode endpoints of the dev device on a given port and populate the async sub-devices list of the notifier. The parse_endpoint callback function is called for each endpoint with the corresponding async sub-device pointer to let the caller initialize the driver-specific part of the async sub-device structure.

The notifier memory shall be zeroed before this function is called on the notifier the first time.

This function may not be called on a registered notifier and may be called on a notifier only once per port.

The struct v4l2_fwnode_endpoint passed to the callback function parse_endpoint is released once the function is finished. If there is a need to retain that configuration, the user needs to allocate memory for it.

Any notifier populated using this function must be released with a call to v4l2_async_notifier_cleanup() after it has been unregistered and the async sub-devices are no longer in use, even if the function returned an error.

Return

0 on success, including when no async sub-devices are found: -ENOMEM if memory allocation failed -EINVAL if graph or endpoint parsing failed Other error codes as returned by parse_endpoint

int v4l2_async_notifier_parse_fwnode_sensor_common(struct device *dev, struct v4l2_async_notifier *notifier)¶: parse common references on sensors for async sub-devices

Parameters

struct device * dev: the device node the properties of which are parsed for references
struct v4l2_async_notifier * notifier: the async notifier where the async subdevs will be added

Description

Parse common sensor properties for remote devices related to the sensor and set up async sub-devices for them.

Any notifier populated using this function must be released with a call to v4l2_async_notifier_release() after it has been unregistered and the async sub-devices are no longer in use, even in the case the function returned an error.

Return

0 on success: -ENOMEM if memory allocation failed -EINVAL if property parsing failed

int v4l2_async_register_fwnode_subdev(struct v4l2_subdev *sd, size_t asd_struct_size, unsigned int *ports, unsigned int num_ports, parse_endpoint_func parse_endpoint)¶: registers a sub-device to the asynchronous sub-device framework and parses fwnode endpoints

Parameters

struct v4l2_subdev * sd: pointer to struct v4l2_subdev
size_t asd_struct_size: size of the driver’s async sub-device struct, including sizeof(struct v4l2_async_subdev). The struct v4l2_async_subdev shall be the first member of the driver’s async sub-device struct, i.e. both begin at the same memory address.
unsigned int * ports: array of port id’s to parse for fwnode endpoints. If NULL, will parse all ports owned by the sub-device.
unsigned int num_ports: number of ports in ports array. Ignored if ports is NULL.
parse_endpoint_func parse_endpoint: Driver’s callback function called on each V4L2 fwnode endpoint. Optional.

Description

This function is just like v4l2_async_register_subdev() with the exception that calling it will also allocate a notifier for the sub-device, parse the sub-device’s firmware node endpoints using v4l2_async_notifier_parse_fwnode_endpoints() or v4l2_async_notifier_parse_fwnode_endpoints_by_port(), and registers the sub-device notifier. The sub-device is similarly unregistered by calling v4l2_async_unregister_subdev().

While registered, the subdev module is marked as in-use.

An error is returned if the module is no longer loaded on any attempts to register it.

1.22. V4L2 fwnode kAPI¶

The Linux Kernel

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