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/kernel.h> 32 #include <sys/malloc.h> 33 #include <sys/module.h> 34 #include <sys/bus.h> 35 36 #include <dev/smbus/smbconf.h> 37 #include <dev/smbus/smbus.h> 38 #include "smbus_if.h" 39 40 /* 41 * smbus_intr() 42 */ 43 void 44 smbus_intr(device_t bus, u_char devaddr, char low, char high, int error) 45 { 46 struct smbus_softc *sc = (struct smbus_softc *)device_get_softc(bus); 47 48 /* call owner's intr routine */ 49 if (sc->owner) 50 SMBUS_INTR(sc->owner, devaddr, low, high, error); 51 52 return; 53 } 54 55 /* 56 * smbus_error() 57 * 58 * Converts an smbus error to a unix error. 59 */ 60 int 61 smbus_error(int smb_error) 62 { 63 int error = 0; 64 65 if (smb_error == SMB_ENOERR) 66 return (0); 67 68 if (smb_error & (SMB_ENOTSUPP)) { 69 error = ENODEV; 70 } else if (smb_error & (SMB_ENOACK)) { 71 error = ENXIO; 72 } else if (smb_error & (SMB_ETIMEOUT)) { 73 error = EWOULDBLOCK; 74 } else if (smb_error & (SMB_EBUSY)) { 75 error = EBUSY; 76 } else { 77 error = EINVAL; 78 } 79 80 return (error); 81 } 82 83 /* 84 * smbus_alloc_bus() 85 * 86 * Allocate a new bus connected to the given parent device 87 */ 88 device_t 89 smbus_alloc_bus(device_t parent) 90 { 91 device_t child; 92 93 /* add the bus to the parent */ 94 child = device_add_child(parent, "smbus", -1, NULL); 95 96 return (child); 97 } 98 99 static int 100 smbus_poll(struct smbus_softc *sc, int how) 101 { 102 int error; 103 104 switch (how) { 105 case (SMB_WAIT | SMB_INTR): 106 error = tsleep(sc, SMBPRI|PCATCH, "smbreq", 0); 107 break; 108 109 case (SMB_WAIT | SMB_NOINTR): 110 error = tsleep(sc, SMBPRI, "smbreq", 0); 111 break; 112 113 default: 114 return (EWOULDBLOCK); 115 break; 116 } 117 118 return (error); 119 } 120 121 /* 122 * smbus_request_bus() 123 * 124 * Allocate the device to perform transfers. 125 * 126 * how : SMB_WAIT or SMB_DONTWAIT 127 */ 128 int 129 smbus_request_bus(device_t bus, device_t dev, int how) 130 { 131 struct smbus_softc *sc = (struct smbus_softc *)device_get_softc(bus); 132 int s, error = 0; 133 134 /* first, ask the underlying layers if the request is ok */ 135 do { 136 error = SMBUS_CALLBACK(device_get_parent(bus), 137 SMB_REQUEST_BUS, (caddr_t)&how); 138 if (error) 139 error = smbus_poll(sc, how); 140 } while (error == EWOULDBLOCK); 141 142 while (!error) { 143 s = splhigh(); 144 if (sc->owner && sc->owner != dev) { 145 splx(s); 146 147 error = smbus_poll(sc, how); 148 } else { 149 sc->owner = dev; 150 151 splx(s); 152 return (0); 153 } 154 155 /* free any allocated resource */ 156 if (error) 157 SMBUS_CALLBACK(device_get_parent(bus), SMB_RELEASE_BUS, 158 (caddr_t)&how); 159 } 160 161 return (error); 162 } 163 164 /* 165 * smbus_release_bus() 166 * 167 * Release the device allocated with smbus_request_dev() 168 */ 169 int 170 smbus_release_bus(device_t bus, device_t dev) 171 { 172 struct smbus_softc *sc = (struct smbus_softc *)device_get_softc(bus); 173 int s, error; 174 175 /* first, ask the underlying layers if the release is ok */ 176 error = SMBUS_CALLBACK(device_get_parent(bus), SMB_RELEASE_BUS, NULL); 177 178 if (error) 179 return (error); 180 181 s = splhigh(); 182 if (sc->owner != dev) { 183 splx(s); 184 return (EACCES); 185 } 186 187 sc->owner = 0; 188 splx(s); 189 190 /* wakeup waiting processes */ 191 wakeup(sc); 192 193 return (0); 194 } 195 196 /* 197 * smbus_get_addr() 198 * 199 * Get the I2C 7 bits address of the device 200 */ 201 u_char 202 smbus_get_addr(device_t dev) 203 { 204 uintptr_t addr; 205 device_t parent = device_get_parent(dev); 206 207 BUS_READ_IVAR(parent, dev, SMBUS_IVAR_ADDR, &addr); 208 209 return ((u_char)addr); 210 } 211