sys/bus/smbus/smbconf.c

   1 /*-
   2  * Copyright (c) 1998, 2001 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 1.13.10.1 2006/09/22 19:19:16 jhb 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/module.h>
  33 #include <sys/bus.h>
  34 #include <sys/thread2.h>
  35
  36 #include "smbconf.h"
  37 #include "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
  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 if (smb_error & (SMB_EABORT | SMB_EBUSERR | SMB_ECOLLI))
  75                 error = EIO;
  76         else
  77                 error = EINVAL;
  78
  79         return (error);
  80 }
  81
  82 static int
  83 smbus_poll(struct smbus_softc *sc, int how)
  84 {
  85         int error;
  86
  87         switch (how) {
  88         case (SMB_WAIT | SMB_INTR):
  89                 error = tsleep(sc, PCATCH, "smbreq", 0);
  90                 break;
  91
  92         case (SMB_WAIT | SMB_NOINTR):
  93                 error = tsleep(sc, 0, "smbreq", 0);
  94                 break;
  95
  96         default:
  97                 error = EWOULDBLOCK;
  98                 break;
  99         }
 100
 101         return (error);
 102 }
 103
 104 /*
 105  * smbus_request_bus()
 106  *
 107  * Allocate the device to perform transfers.
 108  *
 109  * how  : SMB_WAIT or SMB_DONTWAIT
 110  */
 111 int
 112 smbus_request_bus(device_t bus, device_t dev, int how)
 113 {
 114         struct smbus_softc *sc = device_get_softc(bus);
 115         device_t parent;
 116         int error;
 117
 118         /* first, ask the underlying layers if the request is ok */
 119         parent = device_get_parent(bus);
 120         do {
 121                 error = SMBUS_CALLBACK(parent, SMB_REQUEST_BUS, &how);
 122                 if (error)
 123                         error = smbus_poll(sc, how);
 124         } while (error == EWOULDBLOCK);
 125
 126         while (error == 0) {
 127                 crit_enter();
 128                 if (sc->owner && sc->owner != dev) {
 129                         crit_exit();
 130                         error = smbus_poll(sc, how);
 131                         if (error == EWOULDBLOCK)
 132                                 error = 0;
 133                 } else {
 134                         sc->owner = dev;
 135                         crit_exit();
 136                 }
 137                 if (error == 0)
 138                         break;
 139                 /* free any allocated resource */
 140                 SMBUS_CALLBACK(parent, SMB_RELEASE_BUS, &how);
 141         }
 142
 143         return (error);
 144 }
 145
 146 /*
 147  * smbus_release_bus()
 148  *
 149  * Release the device allocated with smbus_request_dev()
 150  */
 151 int
 152 smbus_release_bus(device_t bus, device_t dev)
 153 {
 154         struct smbus_softc *sc = (struct smbus_softc *)device_get_softc(bus);
 155         device_t parent;
 156         int error;
 157
 158         parent = device_get_parent(bus);
 159         /* first, ask the underlying layers if the release is ok */
 160         error = SMBUS_CALLBACK(parent, SMB_RELEASE_BUS, NULL);
 161
 162         if (error)
 163                 return (error);
 164
 165         crit_enter();
 166         if (sc->owner == dev) {
 167                 sc->owner = NULL;
 168
 169                 /* wakeup waiting processes */
 170                 wakeup(sc);
 171         } else {
 172                 error = EACCES;
 173         }
 174         crit_exit();
 175
 176         /* wakeup waiting processes */
 177         wakeup(sc);
 178
 179         return (error);
 180 }