sys/bus/smbus/smbconf.c

   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: src/sys/dev/smbus/smbconf.c,v 1.9 1999/12/03 08:41:08 mdodd Exp $
  27  * $DragonFly: src/sys/bus/smbus/smbconf.c,v 1.5 2005/06/02 20:40:38 dillon Exp $
  28  *
  29  */
  30 #include <sys/param.h>
  31 #include <sys/systm.h>
  32 #include <sys/kernel.h>
  33 #include <sys/malloc.h>
  34 #include <sys/module.h>
  35 #include <sys/bus.h>
  36 #include <sys/thread2.h>
  37
  38 #include "smbconf.h"
  39 #include "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 = (struct smbus_softc *)device_get_softc(bus);
  49
  50         /* call owner's intr routine */
  51         if (sc->owner)
  52                 SMBUS_INTR(sc->owner, devaddr, low, high, error);
  53
  54         return;
  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 {
  79                 error = EINVAL;
  80         }
  81
  82         return (error);
  83 }
  84
  85 /*
  86  * smbus_alloc_bus()
  87  *
  88  * Allocate a new bus connected to the given parent device
  89  */
  90 device_t
  91 smbus_alloc_bus(device_t parent)
  92 {
  93         device_t child;
  94
  95         /* add the bus to the parent */
  96         child = device_add_child(parent, "smbus", -1);
  97
  98         return (child);
  99 }
 100
 101 static int
 102 smbus_poll(struct smbus_softc *sc, int how)
 103 {
 104         int error;
 105
 106         switch (how) {
 107         case (SMB_WAIT | SMB_INTR):
 108                 error = tsleep(sc, PCATCH, "smbreq", 0);
 109                 break;
 110
 111         case (SMB_WAIT | SMB_NOINTR):
 112                 error = tsleep(sc, 0, "smbreq", 0);
 113                 break;
 114
 115         default:
 116                 return (EWOULDBLOCK);
 117                 break;
 118         }
 119
 120         return (error);
 121 }
 122
 123 /*
 124  * smbus_request_bus()
 125  *
 126  * Allocate the device to perform transfers.
 127  *
 128  * how  : SMB_WAIT or SMB_DONTWAIT
 129  */
 130 int
 131 smbus_request_bus(device_t bus, device_t dev, int how)
 132 {
 133         struct smbus_softc *sc = (struct smbus_softc *)device_get_softc(bus);
 134         int error = 0;
 135
 136         /* first, ask the underlying layers if the request is ok */
 137         do {
 138                 error = SMBUS_CALLBACK(device_get_parent(bus),
 139                                                 SMB_REQUEST_BUS, (caddr_t)&how);
 140                 if (error)
 141                         error = smbus_poll(sc, how);
 142         } while (error == EWOULDBLOCK);
 143
 144         while (!error) {
 145                 crit_enter();
 146                 if (sc->owner && sc->owner != dev) {
 147                         crit_exit();
 148                         error = smbus_poll(sc, how);
 149                 } else {
 150                         sc->owner = dev;
 151                         crit_exit();
 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 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         crit_enter();
 182         if (sc->owner != dev) {
 183                 crit_exit();
 184                 return (EACCES);
 185         }
 186         sc->owner = 0;
 187         crit_exit();
 188
 189         /* wakeup waiting processes */
 190         wakeup(sc);
 191
 192         return (0);
 193 }
 194
 195 /*
 196  * smbus_get_addr()
 197  *
 198  * Get the I2C 7 bits address of the device
 199  */
 200 u_char
 201 smbus_get_addr(device_t dev)
 202 {
 203         uintptr_t addr;
 204         device_t parent = device_get_parent(dev);
 205
 206         BUS_READ_IVAR(parent, dev, SMBUS_IVAR_ADDR, &addr);
 207
 208         return ((u_char)addr);
 209 }