device.c

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/*****************************************************************************************
 Copyright (c) 2002-2005 The UbixOS Project
 All rights reserved.

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 permitted provided that the following conditions are met:

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 conditions, the following disclaimer and the list of authors.  Redistributions in binary
 form must reproduce the above copyright notice, this list of conditions, the following
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 contributors may be used to endorse or promote products derived from this software
 without specific prior written permission.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
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 OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 $Id: device_8c-source.html 88 2016-01-12 00:11:29Z reddawg $

*****************************************************************************************/

#include <sys/device.h>
#include <ubixos/spinlock.h>
#include <lib/kmalloc.h>
#include <lib/kprintf.h>
#include <assert.h>

/* Linked list of drivers loaded in the system accessable by the subsystem only */
static struct device_node *devices = 0x0;
static spinLock_t deviceSpinLock = SPIN_LOCK_INITIALIZER;

/*****************************************************************************************

 Function: int deviceAdd(int minor,char type,struct device_interface *devInfo);

 Description: This will add a device to the system

 Notes: 

 05/19/2004 - Improving Upon the spec

*****************************************************************************************/
int device_add(int minor,char type,struct device_interface *devInfo) {
  struct device_node *tmpDev = 0x0;
  
  
  tmpDev = (struct device_node *)kmalloc(sizeof(struct device_node));
  if(tmpDev == NULL)
        kprintf("Error Adding Device: memory failure\n");

  tmpDev->prev    = 0x0;
  tmpDev->minor   = minor;
  tmpDev->type    = type;
  tmpDev->devInfo = devInfo;

  spinLock(&deviceSpinLock);
  tmpDev->next    = devices;
  devices         = tmpDev;
  spinUnlock(&deviceSpinLock);

  if (tmpDev->devInfo->initialized == 0x0)
    return(tmpDev->devInfo->init(tmpDev));
  else
    return(0x0);
  }

/*****************************************************************************************

 Function: struct device_node *deviceFind(int major,int minor);

 Description: This will find a device based on major minor

 Notes: 

 05/19/2004 - Improving Upon the spec

*****************************************************************************************/
struct device_node *device_find(int major,int minor) {
  struct device_node *tmpDev = 0x0;
 
  spinLock(&deviceSpinLock);

  for (tmpDev = devices;tmpDev;tmpDev=tmpDev->next) {
    if ((tmpDev->devInfo->major == major) && (tmpDev->minor == minor)) {
      spinUnlock(&deviceSpinLock);
      return(tmpDev);
      }
    }

  spinUnlock(&deviceSpinLock);
  return(0x0);
  }  


/********************************************************************************************

Function: int deviceRemove(struct *device_node);

Description: This will remove a device based on it's pointer

*********************************************************************************************/
int device_remove(struct device_node *deviceToDelete)
{
struct device_node *current, *previous;


current = devices;
previous=NULL;
spinLock(&deviceSpinLock);
               while(current != NULL)
               {
                  if(current==deviceToDelete) break;
                  else
                  {
                     previous = current;
                     current = current->next;
                  }
               }
               if(current == NULL) 
                {
                  spinUnlock(&deviceSpinLock);
                  return 1;
                }
               else
               {
                  if(current == devices) 
                        devices = devices->next;
                  else 
                        previous->next = current->next;
                  kfree(current);
                  spinUnlock(&deviceSpinLock);
                  return 1;
               }

  spinUnlock(&deviceSpinLock);
return 0x0;
}


/***
 END
 ***/

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