parport_claim(9) [centos man page]

PARPORT_CLAIM(9)					       Parallel Port Devices						  PARPORT_CLAIM(9)

NAME

       parport_claim - claim access to a parallel port device

SYNOPSIS

       int parport_claim(struct pardevice * dev);

ARGUMENTS

       dev
	   pointer to structure representing a device on the port

DESCRIPTION

       This function will not block and so can be used from interrupt context. If parport_claim succeeds in claiming access to the port it returns
       zero and the port is available to use. It may fail (returning non-zero) if the port is in use by another driver and that driver is not
       willing to relinquish control of the port.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014							  PARPORT_CLAIM(9)

PARPORT_REGISTER_POR(9) 				       Parallel Port Devices					   PARPORT_REGISTER_POR(9)

NAME

       parport_register_port - register a parallel port

SYNOPSIS

       struct parport * parport_register_port(unsigned long base, int irq, int dma, struct parport_operations * ops);

ARGUMENTS

       base
	   base I/O address

       irq
	   IRQ line

       dma
	   DMA channel

       ops
	   pointer to the port driver's port operations structure

DESCRIPTION

       When a parallel port (lowlevel) driver finds a port that should be made available to parallel port device drivers, it should call
       parport_register_port. The base, irq, and dma parameters are for the convenience of port drivers, and for ports where they aren't
       meaningful needn't be set to anything special. They can be altered afterwards by adjusting the relevant members of the parport structure
       that is returned and represents the port. They should not be tampered with after calling parport_announce_port, however.

       If there are parallel port device drivers in the system that have registered themselves using parport_register_driver, they are not told
       about the port at this time; that is done by parport_announce_port.

       The ops structure is allocated by the caller, and must not be deallocated before calling parport_remove_port.

       If there is no memory to allocate a new parport structure, this function will return NULL.

COPYRIGHT

Kernel Hackers Manual 2.6.					     July 2010						   PARPORT_REGISTER_POR(9)