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  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #include <IOKit/IOLib.h>
  25 #include "AppleNVRAM.h"
  26
  27
  28 #define super IONVRAMController
  29 OSDefineMetaClassAndStructors(AppleNVRAM, IONVRAMController);
  30
  31
  32 // ****************************************************************************
  33 // start
  34 //
  35 // ****************************************************************************
  36 bool AppleNVRAM::start(IOService *provider)
  37 {
  38   IOItemCount numRanges;
  39   IOMemoryMap *map;
  40
  41   numRanges = provider->getDeviceMemoryCount();
  42
  43   if (numRanges == 1) {
  44     _nvramType = kNVRAMTypeIOMem;
  45
  46     // Get the address of the data register.
  47     map = provider->mapDeviceMemoryWithIndex(0);
  48     if (map == 0) return false;
  49     _nvramData = (UInt8 *)map->getVirtualAddress();
  50
  51   } else if (numRanges == 2) {
  52     _nvramType = kNVRAMTypePort;
  53
  54     // Get the address of the port register.
  55     map = provider->mapDeviceMemoryWithIndex(0);
  56     if (map == 0) return false;
  57     _nvramPort = (UInt8 *)map->getVirtualAddress();
  58
  59     // Get the address of the data register.
  60     map = provider->mapDeviceMemoryWithIndex(1);
  61     if (map == 0) return false;
  62     _nvramData = (UInt8 *)map->getVirtualAddress();
  63
  64   } else {
  65     return false;
  66   }
  67
  68   return super::start(provider);
  69 }
  70
  71 // ****************************************************************************
  72 // read
  73 //
  74 // Read data from the NVRAM and return it in buffer.
  75 //
  76 // ****************************************************************************
  77 IOReturn AppleNVRAM::read(IOByteCount offset, UInt8 *buffer,
  78                           IOByteCount length)
  79 {
  80   UInt32 cnt;
  81
  82   if ((buffer == 0) || (length <= 0) || (offset < 0) ||
  83       (offset + length > kNVRAMImageSize))
  84     return kIOReturnBadArgument;
  85
  86   switch (_nvramType) {
  87   case kNVRAMTypeIOMem :
  88     for (cnt = 0; cnt < length; cnt++) {
  89       buffer[cnt] = _nvramData[(offset + cnt)  << 4];
  90     }
  91     break;
  92
  93   case kNVRAMTypePort:
  94     for (cnt = 0; cnt < length; cnt++) {
  95       *_nvramPort = (offset + length) >> 5;
  96       eieio();
  97       buffer[cnt] = _nvramData[((offset + length) & 0x1F) << 4];
  98     }
  99     break;
 100
 101   default :
 102     return kIOReturnNotReady;
 103   }
 104
 105   return kIOReturnSuccess;
 106 }
 107
 108
 109 // ****************************************************************************
 110 // write
 111 //
 112 // Write data from buffer into NVRAM.
 113 //
 114 // ****************************************************************************
 115 IOReturn AppleNVRAM::write(IOByteCount offset, UInt8 *buffer,
 116                            IOByteCount length)
 117 {
 118   UInt32 cnt;
 119
 120   if ((buffer == 0) || (length <= 0) || (offset < 0) ||
 121       (offset + length > kNVRAMImageSize))
 122     return kIOReturnBadArgument;
 123
 124   switch (_nvramType) {
 125   case kNVRAMTypeIOMem :
 126     for (cnt = 0; cnt < length; cnt++) {
 127       _nvramData[(offset + cnt)  << 4] = buffer[cnt];
 128       eieio();
 129     }
 130     break;
 131
 132   case kNVRAMTypePort:
 133     for (cnt = 0; cnt < length; cnt++) {
 134       *_nvramPort = (offset + length) >> 5;
 135       eieio();
 136       _nvramData[((offset + length) & 0x1F) << 4] = buffer[cnt];
 137       eieio();
 138     }
 139     break;
 140
 141   default :
 142     return kIOReturnNotReady;
 143   }
 144
 145   return kIOReturnSuccess;
 146 }