device_if.m revision 47178
1# 2# Copyright (c) 1998 Doug Rabson 3# All rights reserved. 4# 5# Redistribution and use in source and binary forms, with or without 6# modification, are permitted provided that the following conditions 7# are met: 8# 1. Redistributions of source code must retain the above copyright 9# notice, this list of conditions and the following disclaimer. 10# 2. Redistributions in binary form must reproduce the above copyright 11# notice, this list of conditions and the following disclaimer in the 12# documentation and/or other materials provided with the distribution. 13# 14# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24# SUCH DAMAGE. 25# 26# $Id: device_if.m,v 1.4 1999/05/10 17:06:13 dfr Exp $ 27# 28 29INTERFACE device; 30 31# 32# Default implementations of some methods. 33# 34CODE { 35 static int null_shutdown(device_t dev) 36 { 37 return 0; 38 } 39 40 static int null_suspend(device_t dev) 41 { 42 return 0; 43 } 44 45 static int null_resume(device_t dev) 46 { 47 return 0; 48 } 49}; 50 51# 52# Probe to see if the device is present. Return 0 if the device exists, 53# ENXIO if it cannot be found. For cases where more than one driver 54# matches a device, a priority value can be returned. In this case, 55# success codes are values less than or equal to zero with the highest 56# value representing the best match. Failure codes are represented by 57# positive values and the regular unix error codes should be used for 58# the purpose. 59# 60# If a driver returns a success code which is less than zero, it must 61# not assume that it will be the same driver which is attached to the 62# device. In particular, it must not assume that any values stored in 63# the softc structure will be available for its attach method and any 64# resources allocated during probe must be released and re-allocated 65# if the attach method is called. If a success code of zero is 66# returned, the driver can assume that it will be the one attached. 67# 68# Devices which implement busses should use this method to probe for 69# the existence of devices attached to the bus and add them as 70# children. If this is combined with the use of bus_generic_attach, 71# the child devices will be automatically probed and attached. 72# 73METHOD int probe { 74 device_t dev; 75}; 76 77# 78# Called by a parent bus to add new devices to the bus. 79# 80STATICMETHOD void identify { 81 driver_t *driver; 82 device_t parent; 83}; 84 85# 86# Attach a device to the system. The probe method will have been 87# called and will have indicated that the device exists. This routine 88# should initialise the hardware and allocate other system resources 89# (such as devfs entries). Returns 0 on success. 90# 91METHOD int attach { 92 device_t dev; 93}; 94 95# 96# Detach a device. This can be called if the user is replacing the 97# driver software or if a device is about to be physically removed 98# from the system (e.g. for pccard devices). Returns 0 on success. 99# 100METHOD int detach { 101 device_t dev; 102}; 103 104# 105# This is called during system shutdown to allow the driver to put the 106# hardware into a consistent state for rebooting the computer. 107# 108METHOD int shutdown { 109 device_t dev; 110} DEFAULT null_shutdown; 111 112# 113# This is called by the power-management subsystem when a suspend has been 114# requested by the user or by some automatic mechanism. This gives 115# drivers a chance to veto the suspend or save their configuration before 116# power is removed. 117# 118METHOD int suspend { 119 device_t dev; 120} DEFAULT null_suspend; 121 122METHOD int resume { 123 device_t dev; 124} DEFAULT null_resume; 125