165 lines
6.4 KiB
OCaml
165 lines
6.4 KiB
OCaml
(** Binding to a tiny part of {{:http://libusb.info} libusb}. *)
|
|
|
|
|
|
(** For a more complete binding, have a look at the more complete and more advanced
|
|
{{:https://github.com/letoh/ocaml-usb} ocaml-usb}.
|
|
|
|
I wrote this alternate binding:
|
|
- in order to experiment more in depth with {{:https://github.com/ocamllabs/ocaml-ctypes} Ctypes};
|
|
- and because I needed something more portable than {{:https://github.com/letoh/ocaml-usb} ocaml-usb}: this one is working on Windows, which was not the case of ocaml-usb when I started this project. *)
|
|
|
|
include module type of T
|
|
|
|
(** {1 Getting more of errors} *)
|
|
|
|
val string_of_error: error -> string
|
|
|
|
val description_of_error: error -> string
|
|
|
|
(** {1 Flags} *)
|
|
|
|
(** {2 Request types} *)
|
|
|
|
val request_type_standard: int
|
|
val request_type_class: int
|
|
val request_type_vendor: int
|
|
val request_type_reserved: int
|
|
|
|
(** {2 Endpoint directions} *)
|
|
|
|
val endpoint_direction_in: int
|
|
val endpoint_direction_out: int
|
|
|
|
(** {2 Recipients} *)
|
|
|
|
val recipient_device: int
|
|
val recipient_interface: int
|
|
val recipient_endpoint: int
|
|
val recipient_other: int
|
|
|
|
(** {1 Initialisation} *)
|
|
|
|
val init_libusb: unit -> (unit, error) result
|
|
(** This function must be called before calling any other libusb function. *)
|
|
|
|
val exit_libusb: unit -> unit
|
|
(** Should be called after closing all opened devices and before your application
|
|
terminates. *)
|
|
|
|
val get_version: unit -> version
|
|
(** @return the version of the used C libusb library *)
|
|
|
|
(** {1 Devices enumeration} *)
|
|
|
|
type device
|
|
(** Opaque type representing a C pointer to a device *)
|
|
|
|
val get_device_list: unit -> (device list, error) result
|
|
(** @return a list of C pointers to libusb devices.
|
|
|
|
Each device returned in the list has it's reference counter set to 1. Do not
|
|
forget to {!Libusb.unref_device} each of them after use (see below). *)
|
|
|
|
val unref_device: device -> unit
|
|
(** [unref_device d] decrements the reference count of [d].
|
|
|
|
If the decrement operation causes the reference count to reach zero, the
|
|
device shall be destroyed by libusb C library. *)
|
|
|
|
val unref_devices: device list -> unit
|
|
(** [unref_devices l == List.iter unref_device l] *)
|
|
|
|
val is_vendor: int -> device -> bool
|
|
(** [is_vendor vend d] checks if device [d] vendor id is [vend] *)
|
|
|
|
val is_product: int -> device -> bool
|
|
(** [is_product prod d] checks if device [d] product id is [prod] *)
|
|
|
|
val filter_devices: (device -> bool) -> device list -> device list
|
|
(** [filter_devices f dl] filters [dl] devices list using [f].
|
|
The devices of [dl] which are not part of the returned list are
|
|
unreferenced with {!Libusb.unref_device}. *)
|
|
|
|
(** {1 Device opening} *)
|
|
|
|
type device_handle
|
|
(** A opaque type to manipulate opened devices *)
|
|
|
|
val open_device: ?unref:bool -> device -> (device_handle, error) result
|
|
(** The C libusb library device opening increments the device reference count.
|
|
|
|
If the operation is successfull, and if [unref] is true (which is it's
|
|
default value) {!Libusb.open_device} decrements the device reference counter
|
|
of the device: this allows the device to be destroyed automatically when
|
|
{!Libusb.close_device} will be called. *)
|
|
|
|
val close_device: device_handle -> unit
|
|
(** Closes the device. This operation decrements the reference counter.
|
|
|
|
TODO: make the reference counter decrement optionnal? *)
|
|
|
|
val get_device_descriptor: device -> (device_descriptor, error) result
|
|
|
|
val get_string_descriptor: device_handle -> int -> (string, error) result
|
|
|
|
val claim_interface: device_handle -> int -> (unit, error) result
|
|
(** 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.
|
|
|
|
It is legal to attempt to claim an already-claimed interface, in which case
|
|
libusb just returns without doing anything.
|
|
|
|
Claiming of interfaces is a purely logical operation; it does not cause any
|
|
requests to be sent over the bus. Interface claiming is used to instruct the
|
|
underlying operating system that your application wishes to take ownership of
|
|
the interface.
|
|
|
|
This is a non-blocking function. *)
|
|
|
|
val release_interface: device_handle -> int -> (unit, error) result
|
|
(** Release an interface previously claimed with {! 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. *)
|
|
|
|
(** {1 Synchronous device I/O} *)
|
|
|
|
val control_transfer: device_handle:device_handle -> request_type:int -> request:int -> value:int -> index:int -> buffer:(char, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array1.t -> timeout:int -> unit -> error
|
|
(** Perform a USB control transfer.
|
|
|
|
@param request_type is a bitfield used to parameter the transfer. It can be
|
|
constructed with a logical or between constants. By instance, to make a
|
|
vendor request output, this parameter can be set to [(]{!
|
|
endpoint_direction_in} [ lor ] {! request_type_vendor} [ lor ] {!
|
|
recipient_device} [)].
|
|
|
|
The [value] and [index] fields values should be given in host-endian byte
|
|
order. TODO: check if something can be done to have the OCaml binding take
|
|
care of this. *)
|
|
|
|
val bulk_transfer: device_handle:device_handle -> endpoint:int -> buffer:(char, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array1.t -> timeout:int -> unit -> (int, error) result
|
|
(** Perform a USB bulk transfer.
|
|
|
|
The direction of the transfer is inferred from the direction bits of the
|
|
[endpoint] address. By instance, to write on the [#1] endpoint, [endpoint]
|
|
should be passed : [(] {! Libusb.endpoint_direction_out} [ lor 1] [)].
|
|
|
|
For bulk reads, the length of [buffer] indicates the maximum length of data
|
|
you are expecting to receive. If less data arrives than expected, this
|
|
function will return that data, so be sure to check the transferred output
|
|
parameter.
|
|
|
|
You should also check the transferred parameter for bulk writes. Not all of
|
|
the data may have been written.
|
|
|
|
Also check transferred when dealing with a timeout error code. libusb may
|
|
have to split your transfer into a number of chunks to satisfy underlying O/S
|
|
requirements, meaning that the timeout may expire after the first few chunks
|
|
have completed. libusb is careful not to lose any data that may have been
|
|
transferred; do not assume that timeout conditions indicate a complete lack of
|
|
I/O. *)
|