1IEEE1284_GET_IRQ_FD(3)             Functions            IEEE1284_GET_IRQ_FD(3)
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NAME

6       ieee1284_get_irq_fd, ieee1284_clear_irq - interrupt notification
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SYNOPSIS

9       #include <ieee1284.h>
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11       int ieee1284_get_irq_fd(struct parport *port);
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13       int ieee1284_clear_irq(struct parport *port, unsigned int *count);
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DESCRIPTION

16       If the port has a configured interrupt line and the port type supports
17       interrupt notification, it is possible to obtain a file descriptor that
18       may be used for select(2) or poll(2). Any event (readable, writable or
19       exception) means that an interrupt has been triggered. No operations
20       other than select or poll may be performed on the file descriptor.
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22       The port must be open in order to call ieee1284_get_irq_fd, and must be
23       claimed when using select or poll.
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25       The caller must not close the file descriptor, and may not use it at
26       all when the port is not claimed.
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28       When an interrupt has been detected, the caller must call
29       ieee1284_clear_irq to clear the interrupt condition, at which point the
30       number of interrupts raised can be obtained by supplying a non-NULL
31       count.
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RETURN VALUE

34       For ieee1284_get_irq_fd: If the return value is negative then it is an
35       error code listed below. Otherwise it is a valid file descriptor.
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37       E1284_NOTAVAIL
38           No such file descriptor is available.
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40       E1284_INVALIDPORT
41           The port parameter is invalid (for instance, perhaps the port is
42           not open).
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44       For ieee1284_clear_irq:
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46       E1284_OK
47           The interrupt has been cleared. If count was not NULL the count of
48           interrupts has been atomically stored to count and reset.
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50       E1284_NOTAVAIL
51           The count parameter was not NULL but interrupt counting is not
52           supported on this type of port. The interrupt has been cleared.
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54       E1284_SYS
55           There was a problem clearing the interrupt.
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57       E1284_INVALIDPORT
58           The port parameter is invalid (for instance, perhaps the port is
59           not claimed).
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AUTHOR

62       Tim Waugh <twaugh@redhat.com>
63           Author.
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66       Copyright © 2001-2003 Tim Waugh
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70[FIXME: source]                   01/26/2021            IEEE1284_GET_IRQ_FD(3)
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