1 /*- 2 * Copyright (c) 1998, 2001 Nicolas Souchu 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 * $FreeBSD$ 27 * 28 */ 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/module.h> 32 #include <sys/bus.h> 33 34 #include <dev/smbus/smbconf.h> 35 #include <dev/smbus/smbus.h> 36 #include "smbus_if.h" 37 38 /* 39 * smbus_intr() 40 */ 41 void 42 smbus_intr(device_t bus, u_char devaddr, char low, char high, int error) 43 { 44 struct smbus_softc *sc = (struct smbus_softc *)device_get_softc(bus); 45 46 /* call owner's intr routine */ 47 if (sc->owner) 48 SMBUS_INTR(sc->owner, devaddr, low, high, error); 49 50 return; 51 } 52 53 /* 54 * smbus_error() 55 * 56 * Converts an smbus error to a unix error. 57 */ 58 int 59 smbus_error(int smb_error) 60 { 61 int error = 0; 62 63 if (smb_error == SMB_ENOERR) 64 return (0); 65 66 if (smb_error & (SMB_ENOTSUPP)) { 67 error = ENODEV; 68 } else if (smb_error & (SMB_ENOACK)) { 69 error = ENXIO; 70 } else if (smb_error & (SMB_ETIMEOUT)) { 71 error = EWOULDBLOCK; 72 } else if (smb_error & (SMB_EBUSY)) { 73 error = EBUSY; 74 } else { 75 error = EINVAL; 76 } 77 78 return (error); 79 } 80 81 static int 82 smbus_poll(struct smbus_softc *sc, int how) 83 { 84 int error; 85 86 switch (how) { 87 case (SMB_WAIT | SMB_INTR): 88 error = tsleep(sc, SMBPRI|PCATCH, "smbreq", 0); 89 break; 90 91 case (SMB_WAIT | SMB_NOINTR): 92 error = tsleep(sc, SMBPRI, "smbreq", 0); 93 break; 94 95 default: 96 return (EWOULDBLOCK); 97 break; 98 } 99 100 return (error); 101 } 102 103 /* 104 * smbus_request_bus() 105 * 106 * Allocate the device to perform transfers. 107 * 108 * how : SMB_WAIT or SMB_DONTWAIT 109 */ 110 int 111 smbus_request_bus(device_t bus, device_t dev, int how) 112 { 113 struct smbus_softc *sc = (struct smbus_softc *)device_get_softc(bus); 114 int s, error = 0; 115 116 /* first, ask the underlying layers if the request is ok */ 117 do { 118 error = SMBUS_CALLBACK(device_get_parent(bus), 119 SMB_REQUEST_BUS, (caddr_t)&how); 120 if (error) 121 error = smbus_poll(sc, how); 122 } while (error == EWOULDBLOCK); 123 124 while (!error) { 125 s = splhigh(); 126 if (sc->owner && sc->owner != dev) { 127 splx(s); 128 129 error = smbus_poll(sc, how); 130 } else { 131 sc->owner = dev; 132 133 splx(s); 134 return (0); 135 } 136 137 /* free any allocated resource */ 138 if (error) 139 SMBUS_CALLBACK(device_get_parent(bus), SMB_RELEASE_BUS, 140 (caddr_t)&how); 141 } 142 143 return (error); 144 } 145 146 /* 147 * smbus_release_bus() 148 * 149 * Release the device allocated with smbus_request_dev() 150 */ 151 int 152 smbus_release_bus(device_t bus, device_t dev) 153 { 154 struct smbus_softc *sc = (struct smbus_softc *)device_get_softc(bus); 155 int s, error; 156 157 /* first, ask the underlying layers if the release is ok */ 158 error = SMBUS_CALLBACK(device_get_parent(bus), SMB_RELEASE_BUS, NULL); 159 160 if (error) 161 return (error); 162 163 s = splhigh(); 164 if (sc->owner != dev) { 165 splx(s); 166 return (EACCES); 167 } 168 169 sc->owner = 0; 170 splx(s); 171 172 /* wakeup waiting processes */ 173 wakeup(sc); 174 175 return (0); 176 } 177