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 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/lock.h> 35 #include <sys/module.h> 36 #include <sys/mutex.h> 37 #include <sys/bus.h> 38 39 #include <dev/smbus/smbconf.h> 40 #include <dev/smbus/smbus.h> 41 #include "smbus_if.h" 42 43 /* 44 * smbus_intr() 45 */ 46 void 47 smbus_intr(device_t bus, u_char devaddr, char low, char high, int error) 48 { 49 struct smbus_softc *sc = device_get_softc(bus); 50 51 /* call owner's intr routine */ 52 mtx_lock(&sc->lock); 53 if (sc->owner) 54 SMBUS_INTR(sc->owner, devaddr, low, high, error); 55 mtx_unlock(&sc->lock); 56 } 57 58 /* 59 * smbus_error() 60 * 61 * Converts an smbus error to a unix error. 62 */ 63 int 64 smbus_error(int smb_error) 65 { 66 int error = 0; 67 68 if (smb_error == SMB_ENOERR) 69 return (0); 70 71 if (smb_error & (SMB_ENOTSUPP)) 72 error = ENODEV; 73 else if (smb_error & (SMB_ENOACK)) 74 error = ENXIO; 75 else if (smb_error & (SMB_ETIMEOUT)) 76 error = EWOULDBLOCK; 77 else if (smb_error & (SMB_EBUSY)) 78 error = EBUSY; 79 else if (smb_error & (SMB_EABORT | SMB_EBUSERR | SMB_ECOLLI)) 80 error = EIO; 81 else 82 error = EINVAL; 83 84 return (error); 85 } 86 87 static int 88 smbus_poll(struct smbus_softc *sc, int how) 89 { 90 int error; 91 92 switch (how) { 93 case SMB_WAIT | SMB_INTR: 94 error = msleep(sc, &sc->lock, SMBPRI|PCATCH, "smbreq", 0); 95 break; 96 97 case SMB_WAIT | SMB_NOINTR: 98 error = msleep(sc, &sc->lock, SMBPRI, "smbreq", 0); 99 break; 100 101 default: 102 error = EWOULDBLOCK; 103 break; 104 } 105 106 return (error); 107 } 108 109 /* 110 * smbus_request_bus() 111 * 112 * Allocate the device to perform transfers. 113 * 114 * how : SMB_WAIT or SMB_DONTWAIT 115 */ 116 int 117 smbus_request_bus(device_t bus, device_t dev, int how) 118 { 119 struct smbus_softc *sc = device_get_softc(bus); 120 device_t parent; 121 int error; 122 123 /* first, ask the underlying layers if the request is ok */ 124 parent = device_get_parent(bus); 125 mtx_lock(&sc->lock); 126 do { 127 mtx_unlock(&sc->lock); 128 error = SMBUS_CALLBACK(parent, SMB_REQUEST_BUS, &how); 129 mtx_lock(&sc->lock); 130 131 if (error) 132 error = smbus_poll(sc, how); 133 } while (error == EWOULDBLOCK); 134 135 while (error == 0) { 136 if (sc->owner && sc->owner != dev) 137 error = smbus_poll(sc, how); 138 else { 139 sc->owner = dev; 140 break; 141 } 142 143 /* free any allocated resource */ 144 if (error) { 145 mtx_unlock(&sc->lock); 146 SMBUS_CALLBACK(parent, SMB_RELEASE_BUS, &how); 147 return (error); 148 } 149 } 150 mtx_unlock(&sc->lock); 151 152 return (error); 153 } 154 155 /* 156 * smbus_release_bus() 157 * 158 * Release the device allocated with smbus_request_dev() 159 */ 160 int 161 smbus_release_bus(device_t bus, device_t dev) 162 { 163 struct smbus_softc *sc = device_get_softc(bus); 164 int error; 165 166 /* first, ask the underlying layers if the release is ok */ 167 error = SMBUS_CALLBACK(device_get_parent(bus), SMB_RELEASE_BUS, NULL); 168 169 if (error) 170 return (error); 171 172 mtx_lock(&sc->lock); 173 if (sc->owner == dev) { 174 sc->owner = NULL; 175 176 /* wakeup waiting processes */ 177 wakeup(sc); 178 } else 179 error = EACCES; 180 mtx_unlock(&sc->lock); 181 182 return (error); 183 } 184