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 interrupt 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>.