2.18. 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.

The Linux Kernel

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2.18. V4L2 flash functions and data structures¶