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usbd

Looping

Another way to attach is to loop and attach to all devices (in which case you build the

instance yourself). For example:

for (busno = 0; busno < 10; ++busno) {

for (devno = 0; devno < 64; ++devno) {

memset(&instance, USBD_CONNECT_WILDCARD, sizeof(usbd_device_instance_t));

instance.path = busno, instance.devno = devno;

if (usbd_attach(connection, &instance, 0, &device) == EOK) {

......

}

The degree of “attachedness” depends on how you connected:

• If you speciﬁed insertion/removal callback functions, then you’ll get exclusive

access to the device and can make I/O to it.

• If you didn’t use callbacks and you attached as in the loop above, you get shared

access, so you can only read device conﬁguration.

Returns:

EOK Success.

ENODEV Speciﬁed device doesn’t exist. If in a loop, then there’s nothing at that

devno. If from a callback, then the device has since been removed.

EBUSY A shared/exclusive conﬂict.

ENOMEM No memory for internal device structures.

Classiﬁcation:

QNX Neutrino, QNX 4

Safety

Cancellation point Yes

Interrupt handler No

Signal handler No

Thread Yes

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Belkin F8E211 Guida Utente Pagina 38