libusb
Macros | Enumerations | Functions
Miscellaneous

Macros

#define LIBUSB_CALL
 libusb's Windows calling convention. More...
 
#define libusb_le16_to_cpu   libusb_cpu_to_le16
 Convert a 16-bit value from little-endian to host-endian format. More...
 

Enumerations

enum  libusb_standard_request {
  LIBUSB_REQUEST_GET_STATUS = 0x00, LIBUSB_REQUEST_CLEAR_FEATURE = 0x01, LIBUSB_REQUEST_SET_FEATURE = 0x03, LIBUSB_REQUEST_SET_ADDRESS = 0x05,
  LIBUSB_REQUEST_GET_DESCRIPTOR = 0x06, LIBUSB_REQUEST_SET_DESCRIPTOR = 0x07, LIBUSB_REQUEST_GET_CONFIGURATION = 0x08, LIBUSB_REQUEST_SET_CONFIGURATION = 0x09,
  LIBUSB_REQUEST_GET_INTERFACE = 0x0A, LIBUSB_REQUEST_SET_INTERFACE = 0x0B, LIBUSB_REQUEST_SYNCH_FRAME = 0x0C
}
 Standard requests, as defined in table 9-3 of the USB2 specifications. More...
 
enum  libusb_request_type { LIBUSB_REQUEST_TYPE_STANDARD = (0x00 << 5), LIBUSB_REQUEST_TYPE_CLASS = (0x01 << 5), LIBUSB_REQUEST_TYPE_VENDOR = (0x02 << 5), LIBUSB_REQUEST_TYPE_RESERVED = (0x03 << 5) }
 Request type bits of the bmRequestType field in control transfers. More...
 
enum  libusb_request_recipient { LIBUSB_RECIPIENT_DEVICE = 0x00, LIBUSB_RECIPIENT_INTERFACE = 0x01, LIBUSB_RECIPIENT_ENDPOINT = 0x02, LIBUSB_RECIPIENT_OTHER = 0x03 }
 Recipient bits of the bmRequestType field in control transfers. More...
 
enum  libusb_error {
  LIBUSB_SUCCESS = 0, LIBUSB_ERROR_IO = -1, LIBUSB_ERROR_INVALID_PARAM = -2, LIBUSB_ERROR_ACCESS = -3,
  LIBUSB_ERROR_NO_DEVICE = -4, LIBUSB_ERROR_NOT_FOUND = -5, LIBUSB_ERROR_BUSY = -6, LIBUSB_ERROR_TIMEOUT = -7,
  LIBUSB_ERROR_OVERFLOW = -8, LIBUSB_ERROR_PIPE = -9, LIBUSB_ERROR_INTERRUPTED = -10, LIBUSB_ERROR_NO_MEM = -11,
  LIBUSB_ERROR_NOT_SUPPORTED = -12, LIBUSB_ERROR_OTHER = -99
}
 Error codes. More...
 
enum  libusb_capability { LIBUSB_CAP_HAS_CAPABILITY = 0 }
 Capabilities supported by this instance of libusb. More...
 

Functions

int libusb_has_capability (uint32_t capability)
 Check at runtime if the loaded library has a given capability. More...
 
const char * libusb_error_name (int error_code)
 Returns a constant NULL-terminated string with the ASCII name of a libusb error code. More...
 
struct libusb_versionlibusb_get_version (void)
 Returns a pointer to const struct libusb_version with the version (major, minor, micro, rc, and nano) of the running library.
 

Detailed Description

Macro Definition Documentation

#define LIBUSB_CALL

libusb's Windows calling convention.

Under Windows, the selection of available compilers and configurations means that, unlike other platforms, there is not one true calling convention (calling convention: the manner in which parameters are passed to funcions in the generated assembly code).

Matching the Windows API itself, libusb uses the WINAPI convention (which translates to the stdcall convention) and guarantees that the library is compiled in this way. The public header file also includes appropriate annotations so that your own software will use the right convention, even if another convention is being used by default within your codebase.

The one consideration that you must apply in your software is to mark all functions which you use as libusb callbacks with this LIBUSB_CALL annotation, so that they too get compiled for the correct calling convention.

On non-Windows operating systems, this macro is defined as nothing. This means that you can apply it to your code without worrying about cross-platform compatibility.

#define libusb_le16_to_cpu   libusb_cpu_to_le16

Convert a 16-bit value from little-endian to host-endian format.

On little endian systems, this function does nothing. On big endian systems, the bytes are swapped.

Parameters
xthe little-endian value to convert
Returns
the value in host-endian byte order

Enumeration Type Documentation

Standard requests, as defined in table 9-3 of the USB2 specifications.

Enumerator
LIBUSB_REQUEST_GET_STATUS 

Request status of the specific recipient.

LIBUSB_REQUEST_CLEAR_FEATURE 

Clear or disable a specific feature.

LIBUSB_REQUEST_SET_FEATURE 

Set or enable a specific feature.

LIBUSB_REQUEST_SET_ADDRESS 

Set device address for all future accesses.

LIBUSB_REQUEST_GET_DESCRIPTOR 

Get the specified descriptor.

LIBUSB_REQUEST_SET_DESCRIPTOR 

Used to update existing descriptors or add new descriptors.

LIBUSB_REQUEST_GET_CONFIGURATION 

Get the current device configuration value.

LIBUSB_REQUEST_SET_CONFIGURATION 

Set device configuration.

LIBUSB_REQUEST_GET_INTERFACE 

Return the selected alternate setting for the specified interface.

LIBUSB_REQUEST_SET_INTERFACE 

Select an alternate interface for the specified interface.

LIBUSB_REQUEST_SYNCH_FRAME 

Set then report an endpoint's synchronization frame.

Request type bits of the bmRequestType field in control transfers.

Enumerator
LIBUSB_REQUEST_TYPE_STANDARD 

Standard.

LIBUSB_REQUEST_TYPE_CLASS 

Class.

LIBUSB_REQUEST_TYPE_VENDOR 

Vendor.

LIBUSB_REQUEST_TYPE_RESERVED 

Reserved.

Recipient bits of the bmRequestType field in control transfers.

Values 4 through 31 are reserved.

Enumerator
LIBUSB_RECIPIENT_DEVICE 

Device.

LIBUSB_RECIPIENT_INTERFACE 

Interface.

LIBUSB_RECIPIENT_ENDPOINT 

Endpoint.

LIBUSB_RECIPIENT_OTHER 

Other.

Error codes.

Most libusb functions return 0 on success or one of these codes on failure. You can call libusb_error_name() to retrieve a string representation of an error code.

Enumerator
LIBUSB_SUCCESS 

Success (no error)

LIBUSB_ERROR_IO 

Input/output error.

LIBUSB_ERROR_INVALID_PARAM 

Invalid parameter.

LIBUSB_ERROR_ACCESS 

Access denied (insufficient permissions)

LIBUSB_ERROR_NO_DEVICE 

No such device (it may have been disconnected)

LIBUSB_ERROR_NOT_FOUND 

Entity not found.

LIBUSB_ERROR_BUSY 

Resource busy.

LIBUSB_ERROR_TIMEOUT 

Operation timed out.

LIBUSB_ERROR_OVERFLOW 

Overflow.

LIBUSB_ERROR_PIPE 

Pipe error.

LIBUSB_ERROR_INTERRUPTED 

System call interrupted (perhaps due to signal)

LIBUSB_ERROR_NO_MEM 

Insufficient memory.

LIBUSB_ERROR_NOT_SUPPORTED 

Operation not supported or unimplemented on this platform.

LIBUSB_ERROR_OTHER 

Other error.

Capabilities supported by this instance of libusb.

Test if the loaded library supports a given capability by calling libusb_has_capability().

Enumerator
LIBUSB_CAP_HAS_CAPABILITY 

The libusb_has_capability() API is available.

Function Documentation

int libusb_has_capability ( uint32_t  capability)

Check at runtime if the loaded library has a given capability.

Parameters
capabilitythe libusb_capability to check for
Returns
1 if the running library has the capability, 0 otherwise
const char* libusb_error_name ( int  error_code)

Returns a constant NULL-terminated string with the ASCII name of a libusb error code.

The caller must not free() the returned string.

Parameters
error_codeThe libusb_error code to return the name of.
Returns
The error name, or the string UNKNOWN if the value of error_code is not a known error code.