Copyright (c) 2004, Sun Microsystems, Inc., All Rights Reserved
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
#include <sys/usb/usba.h> usb_frame_number_t usb_get_current_frame_number(dev_info_t *dip);
Solaris DDI specific (Solaris DDI)
Pointer to the device's dev_info structure.
The usb_get_current_frame_number() function retrieves the current logical USB frame number.
Isochronous requests can be started on a particular numbered frame. An offset number of frames (typically between 4 and 10) can be added to the current logical frame number to specify the number of an upcoming frame to start an isochronous request.
The USB specification requires that the frame frequency (the period between start-of-frame packets) is one millisecond. The Solaris operating environment USB implementation uses a running counter of the number of milliseconds since boot as the current logical frame number.
On success, the usb_get_current_frame_number() function returns the current USB frame number. On failure it returns 0. The function fails if dip is NULL.
May be called from user, kernel or interrupt context.
usb_pipe_handle_t handle;
usb_frame_number_t offset = 10;
usb_isoc_req_t *isoc_req;
isoc_req = usb_alloc_isoc_req(...);
...
...
isoc_req->isoc_frame_no = usb_get_current_frame_number(dip) + offset;
isoc_req->isoc_attributes = USB_ATTRS_ISOC_START_FRAME;
...
...
if (usb_pipe_isoc_xfer(handle, isoc_req, 0) != USB_SUCCESS) {
...
}
See attributes(5) for descriptions of the following attributes:
| ATTRIBUTE TYPE ATTRIBUTE VALUE |
| Architecture PCI-based systems |
| Interface stability Committed |
attributes(5), usb_alloc_isoc_req(9F), usb_get_max_pkts_per_isoc_request(9F), usb_pipe_isoc_xfer(9F), usb_pipe_get_max_bulk_transfer_size(9F), usb_isoc_request(9S)