BUS_CONFIG_INTR(9)

NAME

     BUS_CONFIG_INTR -- configure interrupt polarity and trigger mode

SYNOPSIS

     #include <sys/param.h>
     #include <sys/bus.h>

     int
     BUS_CONFIG_INTR(device_t dev, int irq, enum intr_trigger trig,
	 enum intr_polarity pol);

DESCRIPTION

     The BUS_CONFIG_INTR() method allows bus or device drivers to provide
     interrupt polarity and trigger mode to parent busses.  This typically
     bubbles all the way up to the root bus (e.g. nexus) where the necessary
     actions are taken to actually program the hardware.  Since the
     BUS_CONFIG_INTR() method takes an interrupt number, it is assumed but not
     necessarily required that it is called prior to BUS_SETUP_INTR(9).

     The trig argument can be one of:

     INTR_TRIGGER_CONFORM  The interrupt trigger mode is standard for the bus
			   to which the device is attached.

     INTR_TRIGGER_EDGE	   The interrupt is edge triggered.  This means that
			   the interrupt is raised by the rising edge of the
			   signal on the interrupt line.  The signal typically
			   reverts to the original state so as to cause a
			   spike.  INTR_TRIGGER_LEVEL The interrupt is level
			   triggered.  This means that the interrupt is raised
			   when the signal on the interrupt line transitions
			   and remains unchanged after that until the inter-
			   rupt has been serviced, after which the signal
			   transitions back.

     The pol argument can be any one of:

     INTR_POLARITY_CONFORM  The interrupt polarity is standard for the bus to
			    which the device is attached.

     INTR_POLARITY_HIGH     The interrupt is activated by a high voltage on
			    the interrupt line.

     INTR_POLARITY_LOW	    The interrupt is activated by a low voltage on the
			    interrupt line.

RETURN VALUES

     Zero is returned on success, otherwise an appropriate error is returned.

SEE ALSO

     BUS_SETUP_INTR(9), BUS_TEARDOWN_INTR(9), device(9), driver(9)

HISTORY

     The BUS_CONFIG_INTR() method first appeared in FreeBSD 5.2.

AUTHORS

     This manual page was written by Marcel Moolenaar <marcel@xcllnt.net>.