FreeBSD/Linux Kernel Cross Reference
sys/dev/smbus/smbconf.c

     /*-
      * Copyright (c) 1998, 2001 Nicolas Souchu
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
      *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     *
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/lock.h>
    #include <sys/module.h>
    #include <sys/mutex.h>
    #include <sys/bus.h>
    
    #include <dev/smbus/smbconf.h>
    #include <dev/smbus/smbus.h>
    #include "smbus_if.h"
    
    /*
     * smbus_intr()
     */
    void
    smbus_intr(device_t bus, u_char devaddr, char low, char high, int error)
    {
            struct smbus_softc *sc = device_get_softc(bus);
    
            /* call owner's intr routine */
            mtx_lock(&sc->lock);
            if (sc->owner)
                    SMBUS_INTR(sc->owner, devaddr, low, high, error);
            mtx_unlock(&sc->lock);
    }
    
    /*
     * smbus_error()
     *
     * Converts an smbus error to a unix error.
     */
    int
    smbus_error(int smb_error)
    {
            int error = 0;
    
            if (smb_error == SMB_ENOERR)
                    return (0);
            
            if (smb_error & (SMB_ENOTSUPP))
                    error = ENODEV;
            else if (smb_error & (SMB_ENOACK))
                    error = ENXIO;
            else if (smb_error & (SMB_ETIMEOUT))
                    error = EWOULDBLOCK;
            else if (smb_error & (SMB_EBUSY))
                    error = EBUSY;
            else if (smb_error & (SMB_EABORT | SMB_EBUSERR | SMB_ECOLLI))
                    error = EIO;
            else
                    error = EINVAL;
    
            return (error);
    }
    
    static int
    smbus_poll(struct smbus_softc *sc, int how)
    {
            int error;
    
            switch (how) {
            case SMB_WAIT | SMB_INTR:               
                    error = msleep(sc, &sc->lock, SMBPRI|PCATCH, "smbreq", 0);
                    break;
    
            case SMB_WAIT | SMB_NOINTR:
                    error = msleep(sc, &sc->lock, SMBPRI, "smbreq", 0);
                    break;
    
           default:
                   error = EWOULDBLOCK;
                   break;
           }
   
           return (error);
   }
   
   /*
    * smbus_request_bus()
    *
    * Allocate the device to perform transfers.
    *
    * how  : SMB_WAIT or SMB_DONTWAIT
    */
   int
   smbus_request_bus(device_t bus, device_t dev, int how)
   {
           struct smbus_softc *sc = device_get_softc(bus);
           device_t parent;
           int error;
   
           /* first, ask the underlying layers if the request is ok */
           parent = device_get_parent(bus);
           mtx_lock(&sc->lock);
           do {
                   mtx_unlock(&sc->lock);
                   error = SMBUS_CALLBACK(parent, SMB_REQUEST_BUS, &how);
                   mtx_lock(&sc->lock);
   
                   if (error)
                           error = smbus_poll(sc, how);
           } while (error == EWOULDBLOCK);
   
           while (error == 0) {
                   if (sc->owner && sc->owner != dev)
                           error = smbus_poll(sc, how);
                   else {
                           sc->owner = dev;
                           break;
                   }
   
                   /* free any allocated resource */
                   if (error) {
                           mtx_unlock(&sc->lock);
                           SMBUS_CALLBACK(parent, SMB_RELEASE_BUS, &how);
                           return (error);
                   }
           }
           mtx_unlock(&sc->lock);
   
           return (error);
   }
   
   /*
    * smbus_release_bus()
    *
    * Release the device allocated with smbus_request_dev()
    */
   int
   smbus_release_bus(device_t bus, device_t dev)
   {
           struct smbus_softc *sc = device_get_softc(bus);
           int error;
   
           /* first, ask the underlying layers if the release is ok */
           error = SMBUS_CALLBACK(device_get_parent(bus), SMB_RELEASE_BUS, NULL);
   
           if (error)
                   return (error);
   
           mtx_lock(&sc->lock);
           if (sc->owner == dev) {
                   sc->owner = NULL;
   
                   /* wakeup waiting processes */
                   wakeup(sc);
           } else
                   error = EACCES;
           mtx_unlock(&sc->lock);
   
           return (error);
   }

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