illumos: manual page: usb_ep_xdescr

USB_EP_XDESCR_FILL(9F) Kernel Functions for Drivers USB_EP_XDESCR_FILL(9F)

NAME

usb_ep_xdescr_fill - fill extended endpoint description from endpoint data

SYNOPSIS

#include <sys/usb/usba.h>

int
usb_ep_xdescr_fill(uint_t version, dev_info_t *dip, usb_ep_data_t *ep_data,
usb_ep_xdescr_t *ep_xdescr);

INTERFACE STABILITY

illumos DDI specific

PARAMETESR

version Indicates the current version of the usb_ep_xdescr_t
structure the driver is using. Callers should always specify
USB_EP_XDESCR_CURRENT_VERSION.

dip Pointer to the device's dev_info structure.

ep_data Pointer to endpoint data retrieved by calling
usb_lookup_ep_data(9F).

ep_xdescr Pointer to the extended endpoint descriptor that will be
filled out.

DESCRIPTION

The usb_ep_xdescr_fill() function is used to fill in the members of the
extended endpoint descriptor ep_xdescr based on the endpoint descriptor
data in ep_data. Once filled in, ep_xdescr can be used to open a pipe by
calling usb_pipe_xopen(9F).

Prior to USB 3.0, only one descriptor, the usb_ep_descr(9S), was needed to
describe an endpoint. However, with USB 3.0, additional companion
descriptors have been added and are required to successfully open an
endpoint. After calling this, all descriptors needed to successfully open
a pipe will be placed into ep_xdescr and the endpoint data, ep_data, is no
longer required.

CONTEXT

The usb_ep_xdescr_fill() is generally only called from a drivers attach(9E)
entry point; however, it may be called from either user or kernel context.

RETURN VALUES

Upon successful completion, the usb_ep_xdescr_fill() function returns
USB_SUCCESS. Otherwise an error number is returned.

ERRORS

USB_INVALID_ARGS The value of version is unknown, or one of dip, ep_data,
and ep_xdescr was an invalid pointer.

USB_FAILURE An unknown error occurred.