iokit/Drivers/platform/drvAppleNVRAM/AppleNVRAM.cpp

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22
  23 #include <IOKit/IOLib.h>
  24 #include "AppleNVRAM.h"
  25
  26
  27 #define super IONVRAMController
  28 OSDefineMetaClassAndStructors(AppleNVRAM, IONVRAMController);
  29
  30
  31 // ****************************************************************************
  32 // start
  33 //
  34 // ****************************************************************************
  35 bool AppleNVRAM::start(IOService *provider)
  36 {
  37   IOItemCount numRanges;
  38   IOMemoryMap *map;
  39
  40   numRanges = provider->getDeviceMemoryCount();
  41
  42   if (numRanges == 1) {
  43     _nvramType = kNVRAMTypeIOMem;
  44
  45     // Get the address of the data register.
  46     map = provider->mapDeviceMemoryWithIndex(0);
  47     if (map == 0) return false;
  48     _nvramData = (UInt8 *)map->getVirtualAddress();
  49
  50   } else if (numRanges == 2) {
  51     _nvramType = kNVRAMTypePort;
  52
  53     // Get the address of the port register.
  54     map = provider->mapDeviceMemoryWithIndex(0);
  55     if (map == 0) return false;
  56     _nvramPort = (UInt8 *)map->getVirtualAddress();
  57
  58     // Get the address of the data register.
  59     map = provider->mapDeviceMemoryWithIndex(1);
  60     if (map == 0) return false;
  61     _nvramData = (UInt8 *)map->getVirtualAddress();
  62
  63   } else {
  64     return false;
  65   }
  66
  67   return super::start(provider);
  68 }
  69
  70 // ****************************************************************************
  71 // read
  72 //
  73 // Read data from the NVRAM and return it in buffer.
  74 //
  75 // ****************************************************************************
  76 IOReturn AppleNVRAM::read(IOByteCount offset, UInt8 *buffer,
  77                           IOByteCount length)
  78 {
  79   UInt32 cnt;
  80
  81   if ((buffer == 0) || (length <= 0) || (offset < 0) ||
  82       (offset + length > kNVRAMImageSize))
  83     return kIOReturnBadArgument;
  84
  85   switch (_nvramType) {
  86   case kNVRAMTypeIOMem :
  87     for (cnt = 0; cnt < length; cnt++) {
  88       buffer[cnt] = _nvramData[(offset + cnt)  << 4];
  89     }
  90     break;
  91
  92   case kNVRAMTypePort:
  93     for (cnt = 0; cnt < length; cnt++) {
  94       *_nvramPort = (offset + length) >> 5;
  95       eieio();
  96       buffer[cnt] = _nvramData[((offset + length) & 0x1F) << 4];
  97     }
  98     break;
  99
 100   default :
 101     return kIOReturnNotReady;
 102   }
 103
 104   return kIOReturnSuccess;
 105 }
 106
 107
 108 // ****************************************************************************
 109 // write
 110 //
 111 // Write data from buffer into NVRAM.
 112 //
 113 // ****************************************************************************
 114 IOReturn AppleNVRAM::write(IOByteCount offset, UInt8 *buffer,
 115                            IOByteCount length)
 116 {
 117   UInt32 cnt;
 118
 119   if ((buffer == 0) || (length <= 0) || (offset < 0) ||
 120       (offset + length > kNVRAMImageSize))
 121     return kIOReturnBadArgument;
 122
 123   switch (_nvramType) {
 124   case kNVRAMTypeIOMem :
 125     for (cnt = 0; cnt < length; cnt++) {
 126       _nvramData[(offset + cnt)  << 4] = buffer[cnt];
 127       eieio();
 128     }
 129     break;
 130
 131   case kNVRAMTypePort:
 132     for (cnt = 0; cnt < length; cnt++) {
 133       *_nvramPort = (offset + length) >> 5;
 134       eieio();
 135       _nvramData[((offset + length) & 0x1F) << 4] = buffer[cnt];
 136       eieio();
 137     }
 138     break;
 139
 140   default :
 141     return kIOReturnNotReady;
 142   }
 143
 144   return kIOReturnSuccess;
 145 }