Library
Module
Module type
Parameter
Class
Class type
Module for USB communication
handle_error f x
applies f
to x
and returns the result. If the exception Error
or Transport
is raised, it prints a message describing the error and exits with code 2.
type error =
| Error_io
Error on IOs
*)| Error_invalid_param
Invalid parameter. If this error is raised, then there is a bug in ocaml-usb. Please fill a bug report in this case.
*)| Error_access
Access denied to a peripheral
*)| Error_no_device
No such device (it may have been disconnected)
*)| Error_not_found
Entity not found
*)| Error_busy
Resource busy
*)| Error_timeout
Operation timed out
*)| Error_overflow
Overflow
*)| Error_pipe
Pipe error
*)| Error_interrupted
System call interrupted (perhaps due to signal)
*)| Error_no_mem
Insufficient memory
*)| Error_not_supported
Operation not supported or unimplemented on this platform
*)| Error_other
Other error
*)Any function of this module may raise one of the following errors:
exception Error of error * string
Error(error, func_name)
is raised when libusb returns an error. func_name
is a the name of the function which failed.
val error_message : error -> string
error_message error
returns a human readable description of the error
When forced, init
initialises libusb. This is automatically done so you do not need to do it manually. By the way you can do it to catch initialisation errors.
set_debug level
set the debug level.
val get_device_list : unit -> device list
Returns a list of USB devices currently attached to the system.
val get_bus_number : device -> int
Get the number of the bus that a device is connected to.
val get_device_address : device -> int
Get the address of the device on the bus it is connected to.
get_max_packet_size ~device ~direction ~endpoint
Convenience function to retrieve the wMaxPacketSize
value for a particular endpoint in the active device configuration.
Open a device and obtain a device handle.
A handle allows you to perform I/O on the device in question.
val close : handle -> unit
Close a previously opened device handle
val open_device_with : vendor_id:int -> product_id:int -> handle
open_device_with ~vendor_id ~product_id
Convenience function for finding a device with a particular idVendor/idProduct combination.
Determine if a kernel driver is active on an interface.
If a kernel driver is active, you cannot claim the interface, and libusb will be unable to perform I/O.
Detach a kernel driver from an interface.
If successful, you will then be able to claim the interface and perform I/O.
Re-attach an interface's kernel driver, which was previously detached using detach_kernel_driver
.
claim_interface handle interface_number
Claim an interface on a given device handle.
You must claim the interface you wish to use before you can perform I/O on any of its endpoints.
Release an interface previously claimed with libusb_claim_interface().
You should release all claimed interfaces before closing a device handle.
This is a blocking function. A SET_INTERFACE
control request will be sent to the device, resetting interface state to the first alternate setting.
val get_configuration : handle -> configuration Lwt.t
get_configuration handle
returns the current configuration of a device
val set_configuration : handle -> configuration -> unit Lwt.t
set_configuration handle conf
change the current configuration of a device
set_interface_alt_setting handle interface alternate_setting
activates an alternate setting for an interface.
clear_halt handle endpoint
clears the halt/stall condition for an endpoint.
val reset_device : handle -> unit Lwt.t
reset_device handle
reset the given device
module Class : sig ... end
Device class codes
type device_descriptor = {
dd_usb : int;
USB specification release number in binary-coded decimal.
A value of 0x0200 indicates USB 2.0, 0x0110 indicates USB 1.1, etc.
*)dd_device_class : Class.t;
USB-IF class code for the device.
*)dd_device_sub_class : int;
USB-IF subclass code for the device, qualified by the dd_device_class
value.
dd_device_protocol : int;
USB-IF protocol code for the device, qualified by the dd_device_class
and dd_device_subclass
values.
dd_max_packet_size : int;
Maximum packet size for endpoint 0.
*)dd_vendor_id : int;
USB-IF vendor ID.
*)dd_product_id : int;
USB-IF product ID.
*)dd_device : int;
Device release number in binary-coded decimal.
*)dd_index_manufacturer : int;
Index of string descriptor describing manufacturer.
*)dd_index_product : int;
Index of string descriptor describing product.
*)dd_index_serial_number : int;
Index of string descriptor containing device serial number.
*)dd_configurations : int;
Number of possible configurations.
*)}
val get_device_descriptor : device -> device_descriptor
Get the USB device descriptor for a given device.
type endpoint_descriptor = {
ed_endpoint_address : int;
The address of the endpoint described by this descriptor.
*)ed_attributes : int;
ed_max_packet_size : int;
Maximum packet size this endpoint is capable of sending/receiving.
*)ed_interval : int;
Interval for polling endpoint for data transfers.
*)ed_refresh : int;
For audio devices only: the rate at which synchronization feedback is provided.
*)ed_synch_address : int;
For audio devices only: the address if the synch endpoint.
*)}
type interface_descriptor = {
id_interface : int;
Number of this interface.
*)id_alternate_setting : int;
Value used to select this alternate setting for this interface.
*)id_interface_class : Class.t;
USB-IF class code for this interface.
*)id_interface_sub_class : int;
USB-IF subclass code for this interface, qualified by the id_interface_class
value.
id_interface_protocol : int;
USB-IF protocol code for this interface, qualified by the id_interface_class
and id_interface_sub_class
values.
id_index_interface : int;
Index of string descriptor describing this interface.
*)id_endpoints : endpoint_descriptor array;
Array of endpoint descriptors.
*)}
type config_descriptor = {
cd_configuration_value : int;
Identifier value for this configuration
*)cd_index_configuration : int;
Index of string descriptor describing this configuration.
*)cd_attributes : int;
A bitmask, representing configuration characteristics.
*)cd_max_power : int;
Maximum power consumption of the USB device from this bus in this configuration when the device is fully opreation.
Expressed in units of 2 mA.
*)cd_interfaces : interface_descriptor array array;
Array of interfaces supported by this configuration.
cd_interface.(iface).(altsetting)
designate the interface descriptor for interface iface
with alternate setting altsetting
.
}
val get_active_config_descriptor : device -> config_descriptor
Get the USB configuration descriptor for the currently active configuration.
val get_config_descriptor : device -> int -> config_descriptor
Get a USB configuration descriptor based on its index.
val get_config_descriptor_by_value : device -> int -> config_descriptor
Get a USB configuration descriptor with a specific cd_configuration_value
.
module DT : sig ... end
Descriptor types
val get_string_descriptor :
handle ->
?timeout:float ->
?lang_id:int ->
index:int ->
string Lwt.t
Retrieve a string descriptor from a device.
type transfer_error =
| Transfer_error
Transfer failed
*)| Transfer_timed_out
Transfer timed out
*)| Transfer_cancelled
Transfer was cancelled
*)| Transfer_stall
For bulk/interrupt endpoints: halt condition detected (endpoint stalled). For control endpoints: control request not supported.
*)| Transfer_no_device
Device was disconnected
*)| Transfer_overflow
Device sent more data than requested
*)Transfers may fails with any of the following error:
exception Transfer of transfer_error * string
Transfer(error, func_name)
Exception raised when a transfer fail.
val transfer_error_message : transfer_error -> string
transfer_error_message error
val bulk_recv :
handle:handle ->
endpoint:endpoint ->
?timeout:float ->
string ->
int ->
int ->
int Lwt.t
bulk_recv ~handle ~endpoint ?timeout buffer offset length
val bulk_send :
handle:handle ->
endpoint:endpoint ->
?timeout:float ->
string ->
int ->
int ->
int Lwt.t
bulk_send ~handle ~endpoint ?timeout buffer offset length
val interrupt_recv :
handle:handle ->
endpoint:endpoint ->
?timeout:float ->
string ->
int ->
int ->
int Lwt.t
interrupt_recv ~handle ~endpoint ?timeout buffer offset length
val interrupt_send :
handle:handle ->
endpoint:endpoint ->
?timeout:float ->
string ->
int ->
int ->
int Lwt.t
interrupt_send ~handle ~endpoint ?timeout buffer offset length
type iso_result =
| Iso_ok of int
The packet has been transfered successfully
*)| Iso_error of transfer_error * string
Iso_error(error, func_name)
An error occured
Result of the transfer of one packet in an isochronous transfer:
val iso_recv :
handle:handle ->
endpoint:endpoint ->
?timeout:float ->
string ->
int ->
int list ->
iso_result list Lwt.t
val iso_send :
handle:handle ->
endpoint:endpoint ->
?timeout:float ->
string ->
int ->
int list ->
iso_result list Lwt.t
val control_send :
handle:handle ->
endpoint:endpoint ->
?timeout:float ->
?recipient:recipient ->
?request_type:request_type ->
request:request ->
value:int ->
index:int ->
string ->
int ->
int ->
int Lwt.t
Sends a control packet.
val control_recv :
handle:handle ->
endpoint:endpoint ->
?timeout:float ->
?recipient:recipient ->
?request_type:request_type ->
request:request ->
value:int ->
index:int ->
string ->
int ->
int ->
int Lwt.t
Receives a control packet.
module Request : sig ... end
Standard requests