Index: head/lib/libusb/libusb.3
===================================================================
--- head/lib/libusb/libusb.3	(revision 339304)
+++ head/lib/libusb/libusb.3	(revision 339305)
@@ -1,754 +1,758 @@
 .\"
 .\" Copyright (c) 2009 Sylvestre Gallon
 .\"
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
 .\" are met:
 .\" 1. Redistributions of source code must retain the above copyright
 .\"    notice, this list of conditions and the following disclaimer.
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
 .\"
 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .\" $FreeBSD$
 .\"
-.Dd June 23, 2016
+.Dd October 11, 2018
 .Dt LIBUSB 3
 .Os
 .Sh NAME
 .Nm libusb
 .Nd "USB access library"
 .Sh LIBRARY
 USB access library
 .Pq libusb, -lusb
 .Sh SYNOPSIS
 .In libusb.h
 .Sh DESCRIPTION
 The
 .Nm
 library contains interfaces for directly managing a usb device.
 The current implementation supports v1.0 of the libusb API.
 .Sh LIBRARY INITIALISATION AND DEINITIALISATION
 .Ft "const struct libusb_version *"
 .Fn libusb_get_version "void"
 This function returns version information about LibUSB.
 .Pp
 .Ft int
 .Fn libusb_init "libusb_context **ctx"
 This function initialises libusb.
 It must be called at the beginning
 of the program, before other libusb routines are used.
 This function returns 0 on success or LIBUSB_ERROR on
 failure.
 .Pp
 .Ft void
 .Fn libusb_exit "libusb_context *ctx"
 Deinitialise libusb.
 Must be called at the end of the application.
 Other libusb routines may not be called after this function.
 .Pp
 .Ft const char *
 .Fn libusb_strerror "int code"
 Get the ASCII representation of the error given by the
 .Fa code
 argument.
 This function does not return NULL.
 .Pp
 .Ft const char *
 .Fn libusb_error_name "int code"
 Get the ASCII representation of the error enum given by the
 .Fa code
 argument.
 This function does not return NULL.
 .Pp
 .Ft void
 .Fn libusb_set_debug "libusb_context *ctx" "int level"
 Set the debug level to
 .Fa level .
 .Pp
 .Ft ssize_t
 .Fn libusb_get_device_list "libusb_context *ctx" "libusb_device ***list"
 Populate
 .Fa list
 with the list of usb devices available, adding a reference to each
 device in the list.
 All the list entries created by this
 function must have their reference counter
 decremented when you are done with them,
 and the list itself must be freed.
 This
 function returns the number of devices in the list or a LIBUSB_ERROR code.
 .Pp
 .Ft void
 .Fn libusb_free_device_list "libusb_device **list" "int unref_devices"
 Free the list of devices discovered by libusb_get_device_list.
 If
 .Fa unref_device
 is set to 1 all devices in the list have their reference
 counter decremented once.
 .Pp
 .Ft uint8_t
 .Fn libusb_get_bus_number "libusb_device *dev"
 Returns the number of the bus contained by the device
 .Fa dev .
 .Pp
 .Ft uint8_t
 .Fn libusb_get_port_number "libusb_device *dev"
 Returns the port number which the device given by
 .Fa dev
 is attached to.
 .Pp
 .Ft int
 .Fn libusb_get_port_numbers "libusb_device *dev" "uint8_t *buf" "uint8_t bufsize"
 Stores, in the buffer
 .Fa buf
 of size
 .Fa bufsize ,
 the list of all port numbers from root for the device
 .Fa dev .
 .Pp
 .Ft int
 .Fn libusb_get_port_path "libusb_context *ctx" "libusb_device *dev" "uint8_t *buf" "uint8_t bufsize"
 Deprecated function equivalent to libusb_get_port_numbers.
 .Pp
 .Ft uint8_t
 .Fn libusb_get_device_address "libusb_device *dev"
 Returns the device_address contained by the device
 .Fa dev .
 .Pp
 .Ft enum libusb_speed
 .Fn libusb_get_device_speed "libusb_device *dev"
 Returns the wire speed at which the device is connected.
 See the LIBUSB_SPEED_XXX enums for more information.
 LIBUSB_SPEED_UNKNOWN is returned in case of unknown wire speed.
 .Pp
 .Ft int
 .Fn libusb_get_max_packet_size "libusb_device *dev" "unsigned char endpoint"
 Returns the wMaxPacketSize value on success, LIBUSB_ERROR_NOT_FOUND if the
 endpoint does not exist and LIBUSB_ERROR_OTHERS on other failure.
 .Pp
 .Ft int
 .Fn libusb_get_max_iso_packet_size "libusb_device *dev" "unsigned char endpoint"
 Returns the packet size multiplied by the packet multiplier on success,
 LIBUSB_ERROR_NOT_FOUND if the endpoint does not exist and
 LIBUSB_ERROR_OTHERS on other failure.
 .Pp
 .Ft libusb_device *
 .Fn libusb_ref_device "libusb_device *dev"
 Increment the reference counter of the device
 .Fa dev .
 .Pp
 .Ft void
 .Fn libusb_unref_device "libusb_device *dev"
 Decrement the reference counter of the device
 .Fa dev .
 .Pp
 .Ft int
 .Fn libusb_open "libusb_device *dev" "libusb_device_handle **devh"
 Open a device and obtain a device_handle.
 Returns 0 on success,
 LIBUSB_ERROR_NO_MEM on memory allocation problems, LIBUSB_ERROR_ACCESS
 on permissions problems, LIBUSB_ERROR_NO_DEVICE if the device has been
 disconnected and a LIBUSB_ERROR code on other errors.
 .Pp
 .Ft libusb_device_handle *
 .Fn libusb_open_device_with_vid_pid "libusb_context *ctx" "uint16_t vid" "uint16_t pid"
 A convenience function to open a device by vendor and product IDs
 .Fa vid
 and
 .Fa pid .
 Returns NULL on error.
 .Pp
 .Ft void
 .Fn libusb_close "libusb_device_handle *devh"
 Close a device handle.
 .Pp
 .Ft libusb_device *
 .Fn libusb_get_device "libusb_device_handle *devh"
 Get the device contained by devh.
 Returns NULL on error.
 .Pp
 .Ft int
 .Fn libusb_get_configuration "libusb_device_handle *devh" "int *config"
 Returns the value of the current configuration.
 Returns 0
 on success, LIBUSB_ERROR_NO_DEVICE if the device has been disconnected
 and a LIBUSB_ERROR code on error.
 .Pp
 .Ft int
 .Fn libusb_set_configuration "libusb_device_handle *devh" "int config"
 Set the active configuration to
 .Fa config
 for the device contained by
 .Fa devh .
 This function returns 0 on success, LIBUSB_ERROR_NOT_FOUND if the requested
 configuration does not exist, LIBUSB_ERROR_BUSY if the interfaces are currently
 claimed, LIBUSB_ERROR_NO_DEVICE if the device has been disconnected and a
 LIBUSB_ERROR code on failure.
 .Pp
 .Ft int
 .Fn libusb_claim_interface "libusb_device_handle *devh" "int interface_number"
 Claim an interface in a given libusb_handle
 .Fa devh .
 This is a non-blocking function.
 It returns 0 on success, LIBUSB_ERROR_NOT_FOUND
 if the requested interface does not exist, LIBUSB_ERROR_BUSY if a program or
 driver has claimed the interface, LIBUSB_ERROR_NO_DEVICE if the device has
 been disconnected and a LIBUSB_ERROR code on failure.
 .Pp
 .Ft int
 .Fn libusb_release_interface "libusb_device_handle *devh" "int interface_number"
 This function releases an interface.
 All the claimed interfaces on a device must be released
 before closing the device.
 Returns 0 on success, LIBUSB_ERROR_NOT_FOUND if the
 interface was not claimed, LIBUSB_ERROR_NO_DEVICE if the device has been
 disconnected and LIBUSB_ERROR on failure.
 .Pp
 .Ft int
 .Fn libusb_set_interface_alt_setting "libusb_device_handle *dev" "int interface_number" "int alternate_setting"
 Activate an alternate setting for an interface.
 Returns 0 on success,
 LIBUSB_ERROR_NOT_FOUND if the interface was not claimed or the requested
 setting does not exist, LIBUSB_ERROR_NO_DEVICE if the device has been
 disconnected and a LIBUSB_ERROR code on failure.
 .Pp
 .Ft int
 .Fn libusb_clear_halt "libusb_device_handle *devh" "unsigned char endpoint"
 Clear an halt/stall for a endpoint.
 Returns 0 on success, LIBUSB_ERROR_NOT_FOUND
 if the endpoint does not exist, LIBUSB_ERROR_NO_DEVICE if the device has been
 disconnected and a LIBUSB_ERROR code on failure.
 .Pp
 .Ft int
 .Fn libusb_reset_device "libusb_device_handle *devh"
 Perform an USB port reset for an usb device.
 Returns 0 on success,
 LIBUSB_ERROR_NOT_FOUND if re-enumeration is required or if the device has
 been disconnected and a LIBUSB_ERROR code on failure.
 .Pp
 .Ft int
 .Fn libusb_check_connected "libusb_device_handle *devh"
 Test if the USB device is still connected.
 Returns 0 on success,
 LIBUSB_ERROR_NO_DEVICE if it has been disconnected and a LIBUSB_ERROR
 code on failure.
 .Pp
 .Ft int
 .Fn libusb_kernel_driver_active "libusb_device_handle *devh" "int interface"
 Determine if a driver is active on a interface.
 Returns 0 if no kernel driver is active
 and 1 if a kernel driver is active, LIBUSB_ERROR_NO_DEVICE
 if the device has been disconnected and a LIBUSB_ERROR code on failure.
 .Pp
 .Ft int
 .Fn libusb_get_driver "libusb_device_handle *devh" "int interface" "char *name" "int namelen"
 or
 .Ft int
 .Fn libusb_get_driver_np "libusb_device_handle *devh" "int interface" "char *name" "int namelen"
 Copy the name of the driver attached to the given
 .Fa device
 and
 .Fa interface
 into the buffer
 .Fa name
 of length
 .Fa namelen .
 Returns 0 on success, LIBUSB_ERROR_NOT_FOUND if no kernel driver is attached
 to the given interface and LIBUSB_ERROR_INVALID_PARAM if the interface does
 not exist.
 This function is non-portable.
 The buffer pointed to by
 .Fa name
 is only zero terminated on success.
 .Pp
 .Ft int
 .Fn libusb_detach_kernel_driver "libusb_device_handle *devh" "int interface"
 or
 .Ft int
 .Fn libusb_detach_kernel_driver_np "libusb_device_handle *devh" "int interface"
 Detach a kernel driver from an interface.
 This is needed to claim an interface already claimed by a kernel driver.
 Returns 0 on success, LIBUSB_ERROR_NOT_FOUND if no kernel driver was active,
 LIBUSB_ERROR_INVALID_PARAM if the interface does not exist,
 LIBUSB_ERROR_NO_DEVICE if the device has been disconnected
 and a LIBUSB_ERROR code on failure.
 This function is non-portable.
 .Pp
 .Ft int
 .Fn libusb_attach_kernel_driver "libusb_device_handle *devh" "int interface"
 Re-attach an interface kernel driver that was previously detached.
 Returns 0 on success,
 LIBUSB_ERROR_INVALID_PARAM if the interface does not exist,
 LIBUSB_ERROR_NO_DEVICE
 if the device has been disconnected, LIBUSB_ERROR_BUSY if the driver cannot be
 attached because the interface is claimed by a program or driver and a
 LIBUSB_ERROR code on failure.
 .Pp
 .Ft int
 .Fn libusb_set_auto_detach_kernel_driver "libusb_device_handle *devh" "int enable"
 This function enables automatic kernel interface driver detach when an
 interface is claimed.
 When the interface is restored the kernel driver is allowed to be re-attached.
 If the
 .Fa enable
 argument is non-zero the feature is enabled.
 Else disabled.
 Returns 0 on success and a LIBUSB_ERROR code on
 failure.
 .Sh USB DESCRIPTORS
 .Ft int
 .Fn libusb_get_device_descriptor "libusb_device *dev" "libusb_device_descriptor *desc"
 Get the USB device descriptor for the device
 .Fa dev .
 This is a non-blocking function.
 Returns 0 on success and a LIBUSB_ERROR code on
 failure.
 .Pp
 .Ft int
 .Fn libusb_get_active_config_descriptor "libusb_device *dev" "struct libusb_config_descriptor **config"
 Get the USB configuration descriptor for the active configuration.
 Returns 0 on
 success, LIBUSB_ERROR_NOT_FOUND if the device is in
 an unconfigured state
 and a LIBUSB_ERROR code on error.
 .Pp
 .Ft int
 .Fn libusb_get_config_descriptor "libusb_device *dev" "uint8_t config_index" "libusb_config_descriptor **config"
 Get a USB configuration descriptor based on its index
-.Fa idx.
+.Fa idx .
 Returns 0 on success, LIBUSB_ERROR_NOT_FOUND if the configuration does not exist
 and a LIBUSB_ERROR code on error.
 .Pp
 .Ft int
 .Fn libusb_get_config_descriptor_by_value "libusb_device *dev" "uint8 bConfigurationValue" "libusb_config_descriptor **config"
 Get a USB configuration descriptor with a specific bConfigurationValue.
 This is
 a non-blocking function which does not send a request through the device.
 Returns 0
 on success, LIBUSB_ERROR_NOT_FOUND if the configuration
 does not exist and a
 LIBUSB_ERROR code on failure.
 .Pp
 .Ft void
 .Fn libusb_free_config_descriptor "libusb_config_descriptor *config"
 Free a configuration descriptor.
 .Pp
 .Ft int
 .Fn libusb_get_string_descriptor "libusb_device_handle *devh" "uint8_t desc_idx" "uint16_t langid" "unsigned char *data" "int length"
 Retrieve a string descriptor in raw format.
 Returns the number of bytes actually transferred on success
 or a negative LIBUSB_ERROR code on failure.
 .Pp
 .Ft int
 .Fn libusb_get_string_descriptor_ascii "libusb_device_handle *devh" "uint8_t desc_idx" "unsigned char *data" "int length"
 Retrieve a string descriptor in C style ASCII.
 Returns the positive number of bytes in the resulting ASCII string
 on success and a LIBUSB_ERROR code on failure.
 .Pp
 .Ft int
 .Fn libusb_parse_ss_endpoint_comp "const void *buf" "int len" "libusb_ss_endpoint_companion_descriptor **ep_comp"
 This function parses the USB 3.0 endpoint companion descriptor in host endian format pointed to by
 .Fa buf
 and having a length of
 .Fa len .
 Typically these arguments are the extra and extra_length fields of the
 endpoint descriptor.
 On success the pointer to resulting descriptor is stored at the location given by
 .Fa ep_comp .
 Returns zero on success and a LIBUSB_ERROR code on failure.
 On success the parsed USB 3.0 endpoint companion descriptor must be
 freed using the libusb_free_ss_endpoint_comp function.
 .Pp
 .Ft void
 .Fn libusb_free_ss_endpoint_comp "libusb_ss_endpoint_companion_descriptor *ep_comp"
 This function is NULL safe and frees a parsed USB 3.0 endpoint companion descriptor given by
 .Fa ep_comp .
 .Pp
 .Ft int
 .Fn libusb_get_ss_endpoint_companion_descriptor "struct libusb_context *ctx" "const struct libusb_endpoint_descriptor *endpoint" "struct libusb_ss_endpoint_companion_descriptor **ep_comp"
 This function finds and parses the USB 3.0 endpoint companion descriptor given by
 .Fa endpoint .
 Returns zero on success and a LIBUSB_ERROR code on failure.
 On success the parsed USB 3.0 endpoint companion descriptor must be
 freed using the libusb_free_ss_endpoint_companion_descriptor function.
 .Pp
 .Ft void
 .Fn libusb_free_ss_endpoint_companion_descriptor "struct libusb_ss_endpoint_companion_descriptor *ep_comp"
 This function is NULL safe and frees a parsed USB 3.0 endpoint companion descriptor given by
 .Fa ep_comp .
 .Pp
 .Ft int
 .Fn libusb_get_bos_descriptor "libusb_device_handle *handle" "struct libusb_bos_descriptor **bos"
 This function queries the USB device given by
 .Fa handle
 and stores a pointer to a parsed BOS descriptor into
 .Fa bos .
 Returns zero on success and a LIBUSB_ERROR code on failure.
 On success the parsed BOS descriptor must be
 freed using the libusb_free_bos_descriptor function.
 .Pp
 .Ft int
 .Fn libusb_parse_bos_descriptor "const void *buf" "int len" "libusb_bos_descriptor **bos"
 This function parses a Binary Object Store, BOS, descriptor into host endian format pointed to by
 .Fa buf
 and having a length of
 .Fa len .
 On success the pointer to resulting descriptor is stored at the location given by
 .Fa bos .
 Returns zero on success and a LIBUSB_ERROR code on failure.
 On success the parsed BOS descriptor must be freed using the
 libusb_free_bos_descriptor function.
 .Pp
 .Ft void
 .Fn libusb_free_bos_descriptor "libusb_bos_descriptor *bos"
 This function is NULL safe and frees a parsed BOS descriptor given by
 .Fa bos .
 .Pp
 .Ft int
 .Fn libusb_get_usb_2_0_extension_descriptor "struct libusb_context *ctx" "struct libusb_bos_dev_capability_descriptor *dev_cap" "struct libusb_usb_2_0_extension_descriptor **usb_2_0_extension"
 This function parses the USB 2.0 extension descriptor from the descriptor given by
 .Fa dev_cap
 and stores a pointer to the parsed descriptor into
 .Fa usb_2_0_extension .
 Returns zero on success and a LIBUSB_ERROR code on failure.
 On success the parsed USB 2.0 extension descriptor must be freed using the
 libusb_free_usb_2_0_extension_descriptor function.
 .Pp
 .Ft void
 .Fn libusb_free_usb_2_0_extension_descriptor "struct libusb_usb_2_0_extension_descriptor *usb_2_0_extension"
 This function is NULL safe and frees a parsed USB 2.0 extension descriptor given by
 .Fa usb_2_0_extension .
 .Pp
 .Ft int
 .Fn libusb_get_ss_usb_device_capability_descriptor "struct libusb_context *ctx" "struct libusb_bos_dev_capability_descriptor *dev_cap" "struct libusb_ss_usb_device_capability_descriptor **ss_usb_device_capability"
 This function parses the SuperSpeed device capability descriptor from the descriptor given by
 .Fa dev_cap
 and stores a pointer to the parsed descriptor into
 .Fa ss_usb_device_capability .
 Returns zero on success and a LIBUSB_ERROR code on failure.
 On success the parsed SuperSpeed device capability descriptor must be freed using the
 libusb_free_ss_usb_device_capability_descriptor function.
 .Pp
 .Ft void
 .Fn libusb_free_ss_usb_device_capability_descriptor "struct libusb_ss_usb_device_capability_descriptor *ss_usb_device_capability"
 This function is NULL safe and frees a parsed SuperSpeed device capability descriptor given by
 .Fa ss_usb_device_capability .
 .Pp
 .Ft int
 .Fn libusb_get_container_id_descriptor "struct libusb_context *ctx" "struct libusb_bos_dev_capability_descriptor *dev_cap" "struct libusb_container_id_descriptor **container_id"
 This function parses the container ID descriptor from the descriptor given by
 .Fa dev_cap
 and stores a pointer to the parsed descriptor into
 .Fa container_id .
 Returns zero on success and a LIBUSB_ERROR code on failure.
 On success the parsed container ID descriptor must be freed using the
 libusb_free_container_id_descriptor function.
 .Pp
 .Ft void
 .Fn libusb_free_container_id_descriptor "struct libusb_container_id_descriptor *container_id"
 This function is NULL safe and frees a parsed container ID descriptor given by
 .Fa container_id .
 .Sh USB ASYNCHRONOUS I/O
 .Ft struct libusb_transfer *
 .Fn libusb_alloc_transfer "int iso_packets"
 Allocate a transfer with the number of isochronous packet descriptors
 specified by
 .Fa iso_packets .
 Returns NULL on error.
 .Pp
 .Ft void
 .Fn libusb_free_transfer "struct libusb_transfer *tr"
 Free a transfer.
 .Pp
 .Ft int
 .Fn libusb_submit_transfer "struct libusb_transfer *tr"
 This function will submit a transfer and returns immediately.
 Returns 0 on success, LIBUSB_ERROR_NO_DEVICE if
 the device has been disconnected and a
 LIBUSB_ERROR code on other failure.
 .Pp
 .Ft int
 .Fn libusb_cancel_transfer "struct libusb_transfer *tr"
 This function asynchronously cancels a transfer.
 Returns 0 on success and a LIBUSB_ERROR code on failure.
 .Sh USB SYNCHRONOUS I/O
 .Ft int
 .Fn libusb_control_transfer "libusb_device_handle *devh" "uint8_t bmRequestType" "uint8_t bRequest" "uint16_t wValue" "uint16_t wIndex" "unsigned char *data" "uint16_t wLength" "unsigned int timeout"
 Perform a USB control transfer.
 Returns the actual number of bytes
 transferred on success, in the range from and including zero up to and
 including
 .Fa wLength .
 On error a LIBUSB_ERROR code is returned, for example
 LIBUSB_ERROR_TIMEOUT if the transfer timed out, LIBUSB_ERROR_PIPE if the
 control request was not supported, LIBUSB_ERROR_NO_DEVICE if the
 device has been disconnected and another LIBUSB_ERROR code on other failures.
 The LIBUSB_ERROR codes are all negative.
 .Pp
 .Ft int
 .Fn libusb_bulk_transfer "struct libusb_device_handle *devh" "unsigned char endpoint" "unsigned char *data" "int length" "int *transferred" "unsigned int timeout"
 Perform an USB bulk transfer.
 A timeout value of zero means no timeout.
 The timeout value is given in milliseconds.
 Returns 0 on success, LIBUSB_ERROR_TIMEOUT
 if the transfer timed out, LIBUSB_ERROR_PIPE if the control request was not
 supported, LIBUSB_ERROR_OVERFLOW if the device offered more data,
 LIBUSB_ERROR_NO_DEVICE if the device has been disconnected and
 a LIBUSB_ERROR code on other failure.
 .Pp
 .Ft int
 .Fn libusb_interrupt_transfer "struct libusb_device_handle *devh" "unsigned char endpoint" "unsigned char *data" "int length" "int *transferred" "unsigned int timeout"
 Perform an USB Interrupt transfer.
 A timeout value of zero means no timeout.
 The timeout value is given in milliseconds.
 Returns 0 on success, LIBUSB_ERROR_TIMEOUT
 if the transfer timed out, LIBUSB_ERROR_PIPE if the control request was not
 supported, LIBUSB_ERROR_OVERFLOW if the device offered more data,
 LIBUSB_ERROR_NO_DEVICE if the device has been disconnected and
 a LIBUSB_ERROR code on other failure.
 .Sh USB STREAMS SUPPORT
 .Ft int
 .Fn libusb_alloc_streams "libusb_device_handle *dev" "uint32_t num_streams" "unsigned char *endpoints" "int num_endpoints"
 This function verifies that the given number of streams using the
 given number of endpoints is allowed and allocates the resources
 needed to use so-called USB streams.
 Currently only a single stream per endpoint is supported to simplify
 the internals of LibUSB.
 This function returns 0 on success or a LIBUSB_ERROR code on failure.
 .Pp
 .Ft int
 .Fn libusb_free_streams "libusb_device_handle *dev" "unsigned char *endpoints" "int num_endpoints"
 This function release resources needed for streams usage.
 Returns 0 on success or a LIBUSB_ERROR code on failure.
 .Pp
 .Ft void
 .Fn libusb_transfer_set_stream_id "struct libusb_transfer *transfer" "uint32_t stream_id"
 This function sets the stream ID for the given USB transfer.
 .Pp
 .Ft uint32_t
 .Fn libusb_transfer_get_stream_id "struct libusb_transfer *transfer"
 This function returns the stream ID for the given USB transfer.
 If no stream ID is used a value of zero is returned.
 .Sh USB EVENTS
 .Ft int
 .Fn libusb_try_lock_events "libusb_context *ctx"
 Try to acquire the event handling lock.
 Returns 0 if the lock was obtained and 1 if not.
 .Pp
 .Ft void
 .Fn libusb_lock_events "libusb_context *ctx"
 Acquire the event handling lock.
 This function is blocking.
 .Pp
 .Ft void
 .Fn libusb_unlock_events "libusb_context *ctx"
 Release the event handling lock.
 This will wake up any thread blocked
 on
 .Fn libusb_wait_for_event .
 .Pp
 .Ft int
 .Fn libusb_event_handling_ok "libusb_context *ctx"
 Determine if it still OK for this thread to be doing event handling.
 Returns 1
 if event handling can start or continue.
 Returns 0 if this thread must give up
 the events lock.
 .Pp
 .Ft int
 .Fn libusb_event_handler_active "libusb_context *ctx"
 Determine if an active thread is handling events.
 Returns 1 if there is a thread handling events and 0 if there
 are no threads currently handling events.
 .Pp
 .Ft void
 .Fn libusb_lock_event_waiters "libusb_context *ctx"
 Acquire the event_waiters lock.
 This lock is designed to be obtained in the
 situation where you want to be aware when events are completed, but some other
-thread is event handling so calling libusb_handle_events() is not allowed.
+thread is event handling so calling
+.Fn libusb_handle_events
+is not allowed.
 .Pp
 .Ft void
 .Fn libusb_unlock_event_waiters "libusb_context *ctx"
 Release the event_waiters lock.
 .Pp
 .Ft int
 .Fn libusb_wait_for_event "libusb_context *ctx" "struct timeval *tv"
 Wait for another thread to signal completion of an event.
 Must be called
-with the event waiters lock held, see libusb_lock_event_waiters().
+with the event waiters lock held, see
+.Fn libusb_lock_event_waiters .
 This will
 block until the timeout expires or a transfer completes or a thread releases
-the event handling lock through libusb_unlock_events().
+the event handling lock through
+.Fn libusb_unlock_events .
 Returns 0 after a
 transfer completes or another thread stops event handling, and 1 if the
 timeout expired.
 .Pp
 .Ft int
 .Fn libusb_handle_events_timeout_completed "libusb_context *ctx" "struct timeval *tv" "int *completed"
 Handle any pending events by checking if timeouts have expired and by
 checking the set of file descriptors for activity.
 If the
 .Fa completed
 argument is not equal to NULL, this function will
 loop until a transfer completion callback sets the variable pointed to
 by the
 .Fa completed
 argument to non-zero.
 If the
 .Fa tv
 argument is not equal to NULL, this function will return
 LIBUSB_ERROR_TIMEOUT after the given timeout.
 Returns 0 on success, or a LIBUSB_ERROR code on failure or timeout.
 .Pp
 .Ft int
 .Fn libusb_handle_events_completed "libusb_context *ctx" "int *completed"
 Handle any pending events by checking the set of file descriptors for activity.
 If the
 .Fa completed
 argument is not equal to NULL, this function will
 loop until a transfer completion callback sets the variable pointed to
 by the
 .Fa completed
 argument to non-zero.
 Returns 0 on success, or a LIBUSB_ERROR code on failure.
 .Pp
 .Ft int
 .Fn libusb_handle_events_timeout "libusb_context *ctx" "struct timeval *tv"
 Handle any pending events by checking if timeouts have expired and by
 checking the set of file descriptors for activity.
 Returns 0 on success, or a
 LIBUSB_ERROR code on failure or timeout.
 .Pp
 .Ft int
 .Fn libusb_handle_events "libusb_context *ctx"
 Handle any pending events in blocking mode with a sensible timeout.
 Returns 0
 on success and a LIBUSB_ERROR code on failure.
 .Pp
 .Ft int
 .Fn libusb_handle_events_locked "libusb_context *ctx" "struct timeval *tv"
 Handle any pending events by polling file descriptors, without checking if
 another thread is already doing so.
 Must be called with the event lock held.
 .Pp
 .Ft int
 .Fn libusb_get_next_timeout "libusb_context *ctx" "struct timeval *tv"
 Determine the next internal timeout that libusb needs to handle.
 Returns 0
 if there are no pending timeouts, 1 if a timeout was returned, or a LIBUSB_ERROR
 code on failure or timeout.
 .Pp
 .Ft void
 .Fn libusb_set_pollfd_notifiers "libusb_context *ctx" "libusb_pollfd_added_cb added_cb" "libusb_pollfd_removed_cb remove_cb" "void *user_data"
 Register notification functions for file descriptor additions/removals.
 These functions will be invoked for every new or removed file descriptor
 that libusb uses as an event source.
 .Pp
 .Ft const struct libusb_pollfd **
 .Fn libusb_get_pollfds "libusb_context *ctx"
-Retrive a list of file descriptors that should be polled by your main loop as
+Retrieve a list of file descriptors that should be polled by your main loop as
 libusb event sources.
 Returns a NULL-terminated list on success or NULL on failure.
 .Pp
 .Ft int
 .Fn libusb_hotplug_register_callback "libusb_context *ctx" "libusb_hotplug_event events" "libusb_hotplug_flag flags" "int vendor_id" "int product_id" "int dev_class" "libusb_hotplug_callback_fn cb_fn" "void *user_data" "libusb_hotplug_callback_handle *handle"
 This function registers a hotplug filter.
 The
 .Fa events
 argument select which events makes the hotplug filter trigger.
 Available event values are LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED and LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT.
 One or more events must be specified.
 The
 .Fa vendor_id ,
 .Fa product_id
 and
 .Fa dev_class
 arguments can be set to LIBUSB_HOTPLUG_MATCH_ANY to match any value in the USB device descriptor.
 Else the specified value is used for matching.
 If the
 .Fa flags
 argument is set to LIBUSB_HOTPLUG_ENUMERATE, all currently attached and matching USB devices will be passed to the hotplug filter, given by the
 .Fa cb_fn
 argument.
 Else the
 .Fa flags
 argument should be set to LIBUSB_HOTPLUG_NO_FLAGS.
 This function returns 0 upon success or a LIBUSB_ERROR code on failure.
 .Pp
 .Ft int
 .Fn libusb_hotplug_callback_fn "libusb_context *ctx" "libusb_device *device" "libusb_hotplug_event event" "void *user_data"
 The hotplug filter function.
 If this function returns non-zero, the filter is removed.
 Else the filter is kept and can receive more events.
 The
 .Fa user_data
 argument is the same as given when the filter was registered.
 The
 .Fa event
 argument can be either of LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED or LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT.
 .Pp
 .Ft void
 .Fn libusb_hotplug_deregister_callback "libusb_context *ctx" "libusb_hotplug_callback_handle handle"
 This function unregisters a hotplug filter.
 .Sh LIBUSB VERSION 0.1 COMPATIBILITY
 The library is also compliant with LibUSB version 0.1.12.
 .Pp
 .Fn usb_open
 .Fn usb_close
 .Fn usb_get_string
 .Fn usb_get_string_simple
 .Fn usb_get_descriptor_by_endpoint
 .Fn usb_get_descriptor
 .Fn usb_parse_descriptor
 .Fn usb_parse_configuration
 .Fn usb_destroy_configuration
 .Fn usb_fetch_and_parse_descriptors
 .Fn usb_bulk_write
 .Fn usb_bulk_read
 .Fn usb_interrupt_write
 .Fn usb_interrupt_read
 .Fn usb_control_msg
 .Fn usb_set_configuration
 .Fn usb_claim_interface
 .Fn usb_release_interface
 .Fn usb_set_altinterface
 .Fn usb_resetep
 .Fn usb_clear_halt
 .Fn usb_reset
 .Fn usb_strerror
 .Fn usb_init
 .Fn usb_set_debug
 .Fn usb_find_busses
 .Fn usb_find_devices
 .Fn usb_device
 .Fn usb_get_busses
 .Fn usb_check_connected
 .Fn usb_get_driver_np
 .Fn usb_detach_kernel_driver_np
 .Sh SEE ALSO
 .Xr libusb20 3 ,
 .Xr usb 4 ,
 .Xr usbconfig 8 ,
 .Xr usbdump 8
 .Pp
-.Pa http://libusb.sourceforge.net/
+.Lk https://libusb.info/
 .Sh HISTORY
 .Nm
 support first appeared in
 .Fx 8.0 .