ieee1284_open
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Name

ieee1284_open — open a port

Synopsis

#include <ieee1284.h>
int ieee1284_open(port,  
 flags,  
 capabilities); 
struct parport * port;
int  flags;
int * capabilities;

Description

In order to begin using a port it must be opened. Any initial set-up of the port is done at this stage. When an open port is no longer needed it should be closed with ieee1284_close(3).

The possible flags are:

F1284_EXCL

This device cannot share the port with any other device. If this is the case it must be declared at this stage, so that other drivers trying to access the port know not to bother; otherwise they will wait until this driver releases the port, i.e. never.

The iopl/dev-port access methods don't support this yet, but the ppdev ones do.

If capabilities is not NULL it must point to storage for an int, which will be treated as a set of flags, one per bit, which the library sets or clears as appropriate. If a capability is present it will be used when asked for. They are:

CAP1284_RAW

Pin-level access is available. If this capability is present then the following functions are effective: ieee1284_write_data, ieee1284_read_status, ieee1284_wait_status, ieee1284_write_control, ieee1284_read_control, ieee1284_frob_control.

CAP1284_NIBBLE

There is an implementation of nibble mode for this port.

CAP1284_BYTE

There is an implementation of byte mode for this port.

CAP1284_COMPAT

There is an implementation of compatibility mode for this port.

CAP1284_ECP

There is a hardware implementation of ECP mode for this port.

CAP1284_ECPRLE

There is an RLE-aware implementation of ECP mode for this port (the F1284_RLE flag is recognised by the ECP transfer functions).

CAP1284_ECPSWE

There is a software implementation of ECP mode for this port.

CAP1284_BECP

There is an implementation of bounded ECP mode for this port.

CAP1284_EPP

There is a hardware implementation of EPP mode for this port.

CAP1284_EPPSWE

There is a software implementation of EPP mode for this port.

CAP1284_IRQ

An interrupt line is configured for this port and interrupt notifications can be received using ieee1284_get_irq_fd(3).

CAP1284_DMA

A DMA channel is configured for this port.

Return value

E1284_OK

The port is now opened.

E1284_INIT

There was a problem during port initialization. This could be because another driver has opened the port exclusively, or some other reason.

E1284_NOMEM

There is not enough memory.

E1284_NOTAVAIL

One or more of the supplied flags is not supported by this type of port.

E1284_INVALIDPORT

The port parameter is invalid (for instance, the port may already be open).

E1284_SYS

There was a problem at the operating system level. The global variable errno has been set appropriately.

See also

ieee1284_close(3)

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