1 /*- 2 * Copyright (c) 1998 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 /* 82 * smbus_alloc_bus() 83 * 84 * Allocate a new bus connected to the given parent device 85 */ 86 device_t 87 smbus_alloc_bus(device_t parent) 88 { 89 device_t child; 90 91 /* add the bus to the parent */ 92 child = device_add_child(parent, "smbus", -1); 93 94 return (child); 95 } 96 97 static int 98 smbus_poll(struct smbus_softc *sc, int how) 99 { 100 int error; 101 102 switch (how) { 103 case (SMB_WAIT | SMB_INTR): 104 error = tsleep(sc, SMBPRI|PCATCH, "smbreq", 0); 105 break; 106 107 case (SMB_WAIT | SMB_NOINTR): 108 error = tsleep(sc, SMBPRI, "smbreq", 0); 109 break; 110 111 default: 112 return (EWOULDBLOCK); 113 break; 114 } 115 116 return (error); 117 } 118 119 /* 120 * smbus_request_bus() 121 * 122 * Allocate the device to perform transfers. 123 * 124 * how : SMB_WAIT or SMB_DONTWAIT 125 */ 126 int 127 smbus_request_bus(device_t bus, device_t dev, int how) 128 { 129 struct smbus_softc *sc = (struct smbus_softc *)device_get_softc(bus); 130 int s, error = 0; 131 132 /* first, ask the underlying layers if the request is ok */ 133 do { 134 error = SMBUS_CALLBACK(device_get_parent(bus), 135 SMB_REQUEST_BUS, (caddr_t)&how); 136 if (error) 137 error = smbus_poll(sc, how); 138 } while (error == EWOULDBLOCK); 139 140 while (!error) { 141 s = splhigh(); 142 if (sc->owner && sc->owner != dev) { 143 splx(s); 144 145 error = smbus_poll(sc, how); 146 } else { 147 sc->owner = dev; 148 149 splx(s); 150 return (0); 151 } 152 153 /* free any allocated resource */ 154 if (error) 155 SMBUS_CALLBACK(device_get_parent(bus), SMB_RELEASE_BUS, 156 (caddr_t)&how); 157 } 158 159 return (error); 160 } 161 162 /* 163 * smbus_release_bus() 164 * 165 * Release the device allocated with smbus_request_dev() 166 */ 167 int 168 smbus_release_bus(device_t bus, device_t dev) 169 { 170 struct smbus_softc *sc = (struct smbus_softc *)device_get_softc(bus); 171 int s, error; 172 173 /* first, ask the underlying layers if the release is ok */ 174 error = SMBUS_CALLBACK(device_get_parent(bus), SMB_RELEASE_BUS, NULL); 175 176 if (error) 177 return (error); 178 179 s = splhigh(); 180 if (sc->owner != dev) { 181 splx(s); 182 return (EACCES); 183 } 184 185 sc->owner = 0; 186 splx(s); 187 188 /* wakeup waiting processes */ 189 wakeup(sc); 190 191 return (0); 192 } 193 194 /* 195 * smbus_get_addr() 196 * 197 * Get the I2C 7 bits address of the device 198 */ 199 u_char 200 smbus_get_addr(device_t dev) 201 { 202 uintptr_t addr; 203 device_t parent = device_get_parent(dev); 204 205 BUS_READ_IVAR(parent, dev, SMBUS_IVAR_ADDR, &addr); 206 207 return ((u_char)addr); 208 } 209