2.17. V4L2 flash functions and data structures

struct v4l2_flash_ctrl_data

flash control initialization data, filled basing on the features declared by the LED flash class driver in the v4l2_flash_config

Definition

struct v4l2_flash_ctrl_data {
  struct v4l2_ctrl_config config;
  u32 cid;
};

Members

config
initialization data for a control
cid
contains v4l2 flash control id if the config field was initialized, 0 otherwise
struct v4l2_flash_ops

V4L2 flash operations

Definition

struct v4l2_flash_ops {
  int (*external_strobe_set)(struct v4l2_flash *v4l2_flash, bool enable);
  enum led_brightness (*intensity_to_led_brightness) (struct v4l2_flash *v4l2_flash, s32 intensity);
  s32 (*led_brightness_to_intensity) (struct v4l2_flash *v4l2_flash, enum led_brightness);
};

Members

external_strobe_set
Setup strobing the flash by hardware pin state assertion.
intensity_to_led_brightness
Convert intensity to brightness in a device specific manner
led_brightness_to_intensity
convert brightness to intensity in a device specific manner.
struct v4l2_flash_config

V4L2 Flash sub-device initialization data

Definition

struct v4l2_flash_config {
  char dev_name[32];
  struct led_flash_setting intensity;
  u32 flash_faults;
  unsigned int has_external_strobe:1;
};

Members

dev_name
the name of the media entity, unique in the system
intensity
non-flash strobe constraints for the LED
flash_faults
bitmask of flash faults that the LED flash class device can report; corresponding LED_FAULT* bit definitions are available in the header file <linux/led-class-flash.h>
has_external_strobe
external strobe capability
struct v4l2_flash

Flash sub-device context

Definition

struct v4l2_flash {
  struct led_classdev_flash *fled_cdev;
  struct led_classdev *iled_cdev;
  const struct v4l2_flash_ops *ops;
  struct v4l2_subdev sd;
  struct v4l2_ctrl_handler hdl;
  struct v4l2_ctrl **ctrls;
};

Members

fled_cdev
LED flash class device controlled by this sub-device
iled_cdev
LED class device representing indicator LED associated with the LED flash class device
ops
V4L2 specific flash ops
sd
V4L2 sub-device
hdl
flash controls handler
ctrls
array of pointers to controls, whose values define the sub-device state
struct v4l2_flash * v4l2_subdev_to_v4l2_flash(struct v4l2_subdev *sd)

Returns a struct v4l2_flash from the struct v4l2_subdev embedded on it.

Parameters

struct v4l2_subdev *sd
pointer to struct v4l2_subdev
struct v4l2_flash * v4l2_ctrl_to_v4l2_flash(struct v4l2_ctrl *c)

Returns a struct v4l2_flash from the struct v4l2_ctrl embedded on it.

Parameters

struct v4l2_ctrl *c
pointer to struct v4l2_ctrl
struct v4l2_flash * v4l2_flash_init(struct device *dev, struct fwnode_handle *fwn, struct led_classdev_flash *fled_cdev, const struct v4l2_flash_ops *ops, struct v4l2_flash_config *config)

initialize V4L2 flash led sub-device

Parameters

struct device *dev
flash device, e.g. an I2C device
struct fwnode_handle *fwn
fwnode_handle of the LED, may be NULL if the same as device’s
struct led_classdev_flash *fled_cdev
LED flash class device to wrap
const struct v4l2_flash_ops *ops
V4L2 Flash device ops
struct v4l2_flash_config *config
initialization data for V4L2 Flash sub-device

Description

Create V4L2 Flash sub-device wrapping given LED subsystem device. The ops pointer is stored by the V4L2 flash framework. No references are held to config nor its contents once this function has returned.

Return

A valid pointer, or, when an error occurs, the return value is encoded using ERR_PTR(). Use IS_ERR() to check and PTR_ERR() to obtain the numeric return value.

struct v4l2_flash * v4l2_flash_indicator_init(struct device *dev, struct fwnode_handle *fwn, struct led_classdev *iled_cdev, struct v4l2_flash_config *config)

initialize V4L2 indicator sub-device

Parameters

struct device *dev
flash device, e.g. an I2C device
struct fwnode_handle *fwn
fwnode_handle of the LED, may be NULL if the same as device’s
struct led_classdev *iled_cdev
LED flash class device representing the indicator LED
struct v4l2_flash_config *config
initialization data for V4L2 Flash sub-device

Description

Create V4L2 Flash sub-device wrapping given LED subsystem device. The ops pointer is stored by the V4L2 flash framework. No references are held to config nor its contents once this function has returned.

Return

A valid pointer, or, when an error occurs, the return value is encoded using ERR_PTR(). Use IS_ERR() to check and PTR_ERR() to obtain the numeric return value.

void v4l2_flash_release(struct v4l2_flash *v4l2_flash)

release V4L2 Flash sub-device

Parameters

struct v4l2_flash *v4l2_flash
the V4L2 Flash sub-device to release

Description

Release V4L2 Flash sub-device.