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

NAME


usb_lookup_ep_data - Lookup endpoint information

SYNOPSIS


#include <sys/usb/usba.h>


usb_ep_data_t *usb_lookup_ep_data(dev_info_t *dip,
usb_client_dev_data_t *dev_datap, uint_t interface,
uint_t alternate, uint_t skip, uint_t type, uint_t direction);


INTERFACE LEVEL


illumos DDI specific (illumos DDI)

PARAMETERS


dip
Pointer to the device's dev_info structure.


dev_datap
Pointer to a usb_client_dev_data_t structure containing
tree.


interface
Number of interface in which endpoint resides.


alternate
Number of interface alternate setting in which endpoint
resides.


skip
Number of endpoints which match the requested type and
direction to skip before finding one to retrieve.


type
Type of endpoint. This is one of: USB_EP_ATTR_CONTROL,
USB_EP_ATTR_ISOCH, USB_EP_ATTR_BULK, or USB_EP_ATTR_INTR.
Please see usb_pipe_xopen(9F) for more information.


direction
Direction of endpoint, either USB_EP_DIR_OUT or
USB_EP_DIR_IN. This argument is ignored for bi-directional
control endpoints.


DESCRIPTION


The usb_lookup_ep_data() function returns endpoint information from the
tree embedded in client data returned from usb_get_dev_data. It operates
on the current configuration (pointed to by the dev_curr_cfg field of the
usb_client_dev_data_t argument). It skips the first <skip> number of
endpoints it finds which match the specifications of the other arguments,
and then retrieves information on the next matching endpoint it finds.
Note that it does not make a copy of the data, but points to the tree
itself.

RETURN VALUES


On success: the tree node corresponding to the desired endpoint.


On failure: returns NULL. Fails if dip or dev_datap are NULL, if the
desired endpoint does not exist in the tree, or no tree is present in
dev_datap.

CONTEXT


May be called from user, kernel or interrupt context.

EXAMPLES


Retrieve the polling interval for the second interrupt endpoint at
interface 0, alt 3:

uint8_t interval = 0;
usb_ep_data_t *ep_node = usb_lookup_ep_data(
dip, dev_datap, 0, 3, 1, USB_EP_ATTR_INTR, USB_EP_DIR_IN);
if (ep_node != NULL) {
interval = ep_node->ep_descr.bInterval;
}


Retrieve the maximum packet size for the first control pipe at interface
0, alt 4:

uint16_t maxPacketSize = 0;
usb_ep_data_t *ep_node = usb_lookup_ep_data(
dip, dev_datap, 0, 4, 0, USB_EP_ATTR_CONTROL, 0);
if (ep_node != NULL) {
maxPacketSize = ep_node->ep_descr.wMaxPacketSize;
}


ATTRIBUTES


See attributes(7) for descriptions of the following attributes:


+--------------------+-------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------+
|Architecture | PCI-based systems |
+--------------------+-------------------+
|Interface stability | Committed |
+--------------------+-------------------+

SEE ALSO


attributes(7), usb_get_dev_data(9F), usb_pipe_open(9F),
usb_cfg_descr(9S), usb_ep_descr(9S), usb_if_descr(9S)

illumos September 16, 2016 USB_LOOKUP_EP_DATA(9F)