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 * 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/lock.h> 34 #include <sys/module.h> 35 #include <sys/mutex.h> 36 #include <sys/bus.h> 37 38 #include <dev/smbus/smbconf.h> 39 #include <dev/smbus/smbus.h> 40 #include "smbus_if.h" 41 42 /* 43 * smbus_intr() 44 */ 45 void 46 smbus_intr(device_t bus, u_char devaddr, char low, char high, int error) 47 { 48 struct smbus_softc *sc = device_get_softc(bus); 49 50 /* call owner's intr routine */ 51 mtx_lock(&sc->lock); 52 if (sc->owner) 53 SMBUS_INTR(sc->owner, devaddr, low, high, error); 54 mtx_unlock(&sc->lock); 55 } 56 57 /* 58 * smbus_error() 59 * 60 * Converts an smbus error to a unix error. 61 */ 62 int 63 smbus_error(int smb_error) 64 { 65 int error = 0; 66 67 if (smb_error == SMB_ENOERR) 68 return (0); 69 70 if (smb_error & (SMB_ENOTSUPP)) 71 error = ENODEV; 72 else if (smb_error & (SMB_ENOACK)) 73 error = ENXIO; 74 else if (smb_error & (SMB_ETIMEOUT)) 75 error = EWOULDBLOCK; 76 else if (smb_error & (SMB_EBUSY)) 77 error = EBUSY; 78 else if (smb_error & (SMB_EABORT | SMB_EBUSERR | SMB_ECOLLI)) 79 error = EIO; 80 else 81 error = EINVAL; 82 83 return (error); 84 } 85 86 static int 87 smbus_poll(struct smbus_softc *sc, int how) 88 { 89 int error; 90 91 switch (how) { 92 case SMB_WAIT | SMB_INTR: 93 error = msleep(sc, &sc->lock, SMBPRI|PCATCH, "smbreq", 0); 94 break; 95 96 case SMB_WAIT | SMB_NOINTR: 97 error = msleep(sc, &sc->lock, SMBPRI, "smbreq", 0); 98 break; 99 100 default: 101 error = EWOULDBLOCK; 102 break; 103 } 104 105 return (error); 106 } 107 108 /* 109 * smbus_request_bus() 110 * 111 * Allocate the device to perform transfers. 112 * 113 * how : SMB_WAIT or SMB_DONTWAIT 114 */ 115 int 116 smbus_request_bus(device_t bus, device_t dev, int how) 117 { 118 struct smbus_softc *sc = device_get_softc(bus); 119 device_t parent; 120 int error; 121 122 /* first, ask the underlying layers if the request is ok */ 123 parent = device_get_parent(bus); 124 mtx_lock(&sc->lock); 125 do { 126 mtx_unlock(&sc->lock); 127 error = SMBUS_CALLBACK(parent, SMB_REQUEST_BUS, &how); 128 mtx_lock(&sc->lock); 129 130 if (error) 131 error = smbus_poll(sc, how); 132 } while (error == EWOULDBLOCK); 133 134 while (error == 0) { 135 if (sc->owner && sc->owner != dev) 136 error = smbus_poll(sc, how); 137 else { 138 sc->owner = dev; 139 break; 140 } 141 142 /* free any allocated resource */ 143 if (error) { 144 mtx_unlock(&sc->lock); 145 SMBUS_CALLBACK(parent, SMB_RELEASE_BUS, &how); 146 return (error); 147 } 148 } 149 mtx_unlock(&sc->lock); 150 151 return (error); 152 } 153 154 /* 155 * smbus_release_bus() 156 * 157 * Release the device allocated with smbus_request_dev() 158 */ 159 int 160 smbus_release_bus(device_t bus, device_t dev) 161 { 162 struct smbus_softc *sc = device_get_softc(bus); 163 int error; 164 165 /* first, ask the underlying layers if the release is ok */ 166 error = SMBUS_CALLBACK(device_get_parent(bus), SMB_RELEASE_BUS, NULL); 167 168 if (error) 169 return (error); 170 171 mtx_lock(&sc->lock); 172 if (sc->owner == dev) { 173 sc->owner = NULL; 174 175 /* wakeup waiting processes */ 176 wakeup(sc); 177 } else 178 error = EACCES; 179 mtx_unlock(&sc->lock); 180 181 return (error); 182 } 183