1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 1998, 2001 Nicolas Souchu 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * 29 */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/lock.h> 36 #include <sys/module.h> 37 #include <sys/mutex.h> 38 #include <sys/bus.h> 39 40 #include <dev/smbus/smbconf.h> 41 #include <dev/smbus/smbus.h> 42 #include "smbus_if.h" 43 44 /* 45 * smbus_intr() 46 */ 47 void 48 smbus_intr(device_t bus, u_char devaddr, char low, char high, int error) 49 { 50 struct smbus_softc *sc = device_get_softc(bus); 51 52 /* call owner's intr routine */ 53 mtx_lock(&sc->lock); 54 if (sc->owner) 55 SMBUS_INTR(sc->owner, devaddr, low, high, error); 56 mtx_unlock(&sc->lock); 57 } 58 59 /* 60 * smbus_error() 61 * 62 * Converts an smbus error to a unix error. 63 */ 64 int 65 smbus_error(int smb_error) 66 { 67 int error = 0; 68 69 if (smb_error == SMB_ENOERR) 70 return (0); 71 72 if (smb_error & (SMB_ENOTSUPP)) 73 error = ENODEV; 74 else if (smb_error & (SMB_ENOACK)) 75 error = ENXIO; 76 else if (smb_error & (SMB_ETIMEOUT)) 77 error = EWOULDBLOCK; 78 else if (smb_error & (SMB_EBUSY)) 79 error = EBUSY; 80 else if (smb_error & (SMB_EABORT | SMB_EBUSERR | SMB_ECOLLI)) 81 error = EIO; 82 else 83 error = EINVAL; 84 85 return (error); 86 } 87 88 static int 89 smbus_poll(struct smbus_softc *sc, int how) 90 { 91 int error; 92 93 switch (how) { 94 case SMB_WAIT | SMB_INTR: 95 error = msleep(sc, &sc->lock, SMBPRI|PCATCH, "smbreq", 0); 96 break; 97 98 case SMB_WAIT | SMB_NOINTR: 99 error = msleep(sc, &sc->lock, SMBPRI, "smbreq", 0); 100 break; 101 102 default: 103 error = EWOULDBLOCK; 104 break; 105 } 106 107 return (error); 108 } 109 110 /* 111 * smbus_request_bus() 112 * 113 * Allocate the device to perform transfers. 114 * 115 * how : SMB_WAIT or SMB_DONTWAIT 116 */ 117 int 118 smbus_request_bus(device_t bus, device_t dev, int how) 119 { 120 struct smbus_softc *sc = device_get_softc(bus); 121 device_t parent; 122 int error; 123 124 /* first, ask the underlying layers if the request is ok */ 125 parent = device_get_parent(bus); 126 mtx_lock(&sc->lock); 127 do { 128 mtx_unlock(&sc->lock); 129 error = SMBUS_CALLBACK(parent, SMB_REQUEST_BUS, &how); 130 mtx_lock(&sc->lock); 131 132 if (error) 133 error = smbus_poll(sc, how); 134 } while (error == EWOULDBLOCK); 135 136 while (error == 0) { 137 if (sc->owner && sc->owner != dev) 138 error = smbus_poll(sc, how); 139 else { 140 sc->owner = dev; 141 break; 142 } 143 144 /* free any allocated resource */ 145 if (error) { 146 mtx_unlock(&sc->lock); 147 SMBUS_CALLBACK(parent, SMB_RELEASE_BUS, &how); 148 return (error); 149 } 150 } 151 mtx_unlock(&sc->lock); 152 153 return (error); 154 } 155 156 /* 157 * smbus_release_bus() 158 * 159 * Release the device allocated with smbus_request_dev() 160 */ 161 int 162 smbus_release_bus(device_t bus, device_t dev) 163 { 164 struct smbus_softc *sc = device_get_softc(bus); 165 int error; 166 167 /* first, ask the underlying layers if the release is ok */ 168 error = SMBUS_CALLBACK(device_get_parent(bus), SMB_RELEASE_BUS, NULL); 169 170 if (error) 171 return (error); 172 173 mtx_lock(&sc->lock); 174 if (sc->owner == dev) { 175 sc->owner = NULL; 176 177 /* wakeup waiting processes */ 178 wakeup(sc); 179 } else 180 error = EACCES; 181 mtx_unlock(&sc->lock); 182 183 return (error); 184 } 185