Tizen Native API  10.0
Functions | Typedefs
Hotplug event notification
USB Host

This API is used to register callbacks to be called when devices are connected or disconnected.

This API allows us to receive information on appearing and disappearing devices.

Overview

Functions described here can be used to register callbacks to be called on events such as device connection or disconnection.

Related Features

This API is related with the following features:

  • http://tizen.org/feature/usb.host

It is recommended to design feature related codes in your application for reliability.

You can check if a device supports the related features for this API by using System Information, thereby controlling the procedure of your application.

To ensure your application is only running on the device with specific features, please define the features in your manifest file using the manifest editor in the SDK.

More details on featuring your application can be found from Feature Element.

Functions

int usb_host_set_hotplug_cb (usb_host_context_h ctx, usb_host_hotplug_cb cb, usb_host_hotplug_event_e event, void *user_data, usb_host_hotplug_h *handle)
 Sets a callback function to be invoked when a device is connected or disconnected.
int usb_host_unset_hotplug_cb (usb_host_hotplug_h handle)
 Unsets the (dis)connection hotplug callback function.

Typedefs

typedef struct usb_host_hotplug_s * usb_host_hotplug_h
 An opaque handle representing a USB hotplug callback manager.
typedef void(* usb_host_hotplug_cb )(usb_host_device_h dev, void *user_data)
 An type representing a USB hotplug callback handler.

Typedef Documentation

typedef void(* usb_host_hotplug_cb)(usb_host_device_h dev, void *user_data)

An type representing a USB hotplug callback handler.

The device handle should be unreffed with usb_host_unref_device() when no longer needed.

Since :
4.0
Parameters:
[in]devDevice which was connected/disconnected
[in]user_dataUser data pointer passed on callback registration
typedef struct usb_host_hotplug_s* usb_host_hotplug_h

An opaque handle representing a USB hotplug callback manager.

This handle is used for managing registered hotplug callbacks.

Since :
4.0

Enumeration Type Documentation

enum usb_host_hotplug_event_e

An enumeration representing USB hotplug event types.

Says whether a hotplug event was about attachment or detachment.

Since :
4.0
Enumerator:
USB_HOST_HOTPLUG_EVENT_ATTACH 

Device was connected 

USB_HOST_HOTPLUG_EVENT_DETACH 

Device was disconnected 

USB_HOST_HOTPLUG_EVENT_ANY 

Any event 

Function Documentation

int usb_host_set_hotplug_cb ( usb_host_context_h  ctx,
usb_host_hotplug_cb  cb,
usb_host_hotplug_event_e  event,
void *  user_data,
usb_host_hotplug_h *  handle 
)

Sets a callback function to be invoked when a device is connected or disconnected.

After this call, a callback function will be invoked whenever a device is connected or disconnected.

Since :
4.0
Parameters:
[in]ctxContext handle
[in]cbThe callback function to be registered
[in]eventEvent that will trigger registered callback
[in]user_dataThe user data to be passed to the callback function
[out]handleHandle of the registered callback
Returns:
0 on success, negative error code on error
Return values:
USB_HOST_ERROR_NONESuccessful
USB_HOST_ERROR_NOT_SUPPORTEDNot supported
USB_HOST_ERROR_INVALID_PARAMETERInvalid parameter was passed
USB_HOST_ERROR_OUT_OF_MEMORYOut of memory
#include <usb_host.h>

void hotplug_callback(usb_host_device_h dev, void *user_data)
{
    struct our_data_type *callback_data = user_data;

    process_new_device(data);
}

usb_host_hotplug_h set_callback(usb_host_context_h ctx)
{
    struct our_data_type *callback_data = create_callback_data();
    int ret;
    usb_host_hotplug_h handle;

    ret = usb_host_set_hotplug_cb(ctx, hotplug_callback, USB_HOST_HOTPLUG_EVENT_ATTACH, callback_data, &handle);
    if (ret != USB_HOST_ERROR_NONE)
        handle_error(ret);

    return handle;
}
int usb_host_unset_hotplug_cb ( usb_host_hotplug_h  handle)

Unsets the (dis)connection hotplug callback function.

After this call, the callback will not be connected anymore.

Since :
4.0
Parameters:
[in]handleHandle of the callback to be unregistered
Returns:
0 on success, negative error code on error
Return values:
USB_HOST_ERROR_NONESuccessful
USB_HOST_ERROR_INVALID_PARAMETERInvalid parameter was passed
USB_HOST_ERROR_NOT_SUPPORTEDNot supported
#include <usb_host.h>

void unset_callback(usb_host_hotplug_h handle, struct our_data_type *callback_data)
{
    int ret = usb_host_unset_hotplug_cb(handle);
    if (ret != USB_HOST_ERROR_NONE)
        handle_error(ret);

    // Make sure the callback is not running in parallel!
    destroy_callback_data(callback_data);
}