Device operations

Device operations — Device operation functions

Functions

struct fp_dev * FP_DEV ()
struct fp_img_dev * FP_IMG_DEV ()
void fp_dev_set_instance_data ()
void * FP_INSTANCE_DATA ()
libusb_device_handle * fpi_dev_get_usb_dev ()
struct fp_print_data * fpi_dev_get_verify_data ()
void fpi_dev_set_nr_enroll_stages ()

Types and Values

struct fp_img_dev

Includes

#include <fpi-dev.h>

Description

Those macros and functions will help get access to and from struct fp_dev, and struct fp_img_dev types, as well as get and set the instance struct data, eg. the structure containing the data specific to each driver.

Functions

FP_DEV ()

struct fp_dev *
FP_DEV (struct fp_img_dev *dev);

Returns the struct fp_dev associated with dev , or NULL on failure.

Parameters

dev

a struct fp_img_dev

 

Returns

a struct fp_dev or NULL


FP_IMG_DEV ()

struct fp_img_dev *
FP_IMG_DEV (struct fp_dev *dev);

Returns a struct fp_img_dev associated with dev , or NULL on failure.

Parameters

dev

a struct fp_dev representing an imaging device.

 

Returns

a struct fp_img_dev or NULL


fp_dev_set_instance_data ()

void
fp_dev_set_instance_data (struct fp_dev *dev,
                          void *instance_data);

Set the instance data for a struct fp_dev. This is usually a structure private to the driver used to keep state and pass it as user_data to asynchronous functions.

The core does not do any memory management for this data, so the driver itself will have to create and free its own structure when appropriate.

Parameters

dev

a struct fp_dev

 

instance_data

a pointer to the instance data

 

FP_INSTANCE_DATA ()

void *
FP_INSTANCE_DATA (struct fp_dev *dev);

Returns the instance data set using fp_dev_set_instance_data().

Parameters

dev

a struct fp_dev

 

fpi_dev_get_usb_dev ()

libusb_device_handle *
fpi_dev_get_usb_dev (struct fp_dev *dev);

Returns the libusb_device_handle associated with dev or NULL if none are associated.

Parameters

dev

a struct fp_dev

 

Returns

a libusb_device_handle pointer or NULL


fpi_dev_get_verify_data ()

struct fp_print_data *
fpi_dev_get_verify_data (struct fp_dev *dev);

Returns the verify data associated with dev . This is usually only necessary for primitive devices which need to have access to the raw verify data as it might have been stored on disk.

Parameters

dev

a struct fp_dev

 

Returns

a struct fp_print_data pointer or NULL


fpi_dev_set_nr_enroll_stages ()

void
fpi_dev_set_nr_enroll_stages (struct fp_dev *dev,
                              int nr_enroll_stages);

Sets the number of enroll stages that this device uses. This is usually only necessary for primitive devices which have a hard-coded number of enroll stages baked into their protocol.

Parameters

dev

a struct fp_dev

 

nr_enroll_stages

the number of enroll stages

 

Types and Values

struct fp_img_dev

struct fp_img_dev;

fp_img_dev is an opaque structure type. You must access it using the appropriate functions.