freebsd-dev/sys/kern/bus_if.m
Doug Rabson b1bf661000 [Add missing files from previous commit]
Major changes to the generic device framework for FreeBSD/alpha:

* Eliminate bus_t and make it possible for all devices to have
  attached children.

* Support dynamically extendable interfaces for drivers to replace
  both the function pointers in driver_t and bus_ops_t (which has been
  removed entirely.  Two system defined interfaces have been defined,
  'device' which is mandatory for all devices and 'bus' which is
  recommended for all devices which support attached children.

* In addition, the alpha port defines two simple interfaces 'clock'
  for attaching various real time clocks to the system and 'mcclock'
  for the many different variations of mc146818 clocks which can be
  attached to different alpha platforms.  This eliminates two more
  function pointer tables in favour of the generic method dispatch
  system provided by the device framework.

Future device interfaces may include:

* cdev and bdev interfaces for devfs to use in replacement for specfs
  and the fixed interfaces bdevsw and cdevsw.

* scsi interface to replace struct scsi_adapter (not sure how this
  works in CAM but I imagine there is something similar there).

* various tailored interfaces for different bus types such as pci,
  isa, pccard etc.
1998-06-14 13:53:12 +00:00

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Objective-C

#
# Copyright (c) 1998 Doug Rabson
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# $Id$
#
INTERFACE bus
#
# This is called from system code which prints out a description of a
# device. It should describe the attachment that the child has with
# the parent. For instance the TurboLaser bus prints which node the
# device is attached to.
#
METHOD void print_child {
device_t dev;
device_t child;
};
#
# These two methods manage a bus specific set of instance variables of
# a child device. The intention is that each different type of bus
# defines a set of appropriate instance variables (such as ports and
# irqs for ISA bus etc.)
#
# This information could be given to the child device as a struct but
# that makes it hard for a bus to add or remove variables without
# forcing an edit and recompile for all drivers which may not be
# possible for vendor supplied binary drivers.
#
# Read an instance variable. Return 0 on success.
#
METHOD int read_ivar {
device_t dev;
device_t child;
int index;
u_long *result;
};
#
# Write an instance variable. Return 0 on success.
#
METHOD int write_ivar {
device_t dev;
device_t child;
int index;
u_long value;
};
#
# Register an interrupt handler for the child device. The handler
# will be called with the value 'arg' as its only argument.
#
METHOD int map_intr {
device_t dev;
device_t child;
driver_intr_t *intr;
void *arg;
};