iokit/Drivers/platform/drvAppleNVRAM/AppleNVRAM.cpp

   1 /*
   2  * Copyright (c) 1998-2008 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include <IOKit/IOLib.h>
  30 #include "AppleNVRAM.h"
  31
  32
  33 #define super IONVRAMController
  34 OSDefineMetaClassAndStructors(AppleNVRAM, IONVRAMController);
  35
  36
  37 // ****************************************************************************
  38 // start
  39 //
  40 // ****************************************************************************
  41 bool AppleNVRAM::start(IOService *provider)
  42 {
  43   IOItemCount numRanges;
  44   IOMemoryMap *map;
  45
  46   numRanges = provider->getDeviceMemoryCount();
  47
  48   if (numRanges == 1) {
  49     _nvramType = kNVRAMTypeIOMem;
  50
  51     // Get the address of the data register.
  52     map = provider->mapDeviceMemoryWithIndex(0);
  53     if (map == 0) return false;
  54     _nvramData = (UInt8 *)map->getVirtualAddress();
  55
  56   } else if (numRanges == 2) {
  57     _nvramType = kNVRAMTypePort;
  58
  59     // Get the address of the port register.
  60     map = provider->mapDeviceMemoryWithIndex(0);
  61     if (map == 0) return false;
  62     _nvramPort = (UInt8 *)map->getVirtualAddress();
  63
  64     // Get the address of the data register.
  65     map = provider->mapDeviceMemoryWithIndex(1);
  66     if (map == 0) return false;
  67     _nvramData = (UInt8 *)map->getVirtualAddress();
  68
  69   } else {
  70     return false;
  71   }
  72
  73   return super::start(provider);
  74 }
  75
  76 // ****************************************************************************
  77 // read
  78 //
  79 // Read data from the NVRAM and return it in buffer.
  80 //
  81 // ****************************************************************************
  82 IOReturn AppleNVRAM::read(IOByteCount offset, UInt8 *buffer,
  83                           IOByteCount length)
  84 {
  85   UInt32 cnt;
  86
  87   // length and offset can't be less than zero (unsigned), so we don't check
  88   if ((buffer == 0) || (length == 0) || (offset + length > kNVRAMImageSize))
  89     return kIOReturnBadArgument;
  90
  91   switch (_nvramType) {
  92   case kNVRAMTypeIOMem :
  93     for (cnt = 0; cnt < length; cnt++) {
  94       buffer[cnt] = _nvramData[(offset + cnt)  << 4];
  95     }
  96     break;
  97
  98   case kNVRAMTypePort:
  99     for (cnt = 0; cnt < length; cnt++) {
 100       *_nvramPort = (offset + length) >> 5;
 101       eieio();
 102       buffer[cnt] = _nvramData[((offset + length) & 0x1F) << 4];
 103     }
 104     break;
 105
 106   default :
 107     return kIOReturnNotReady;
 108   }
 109
 110   return kIOReturnSuccess;
 111 }
 112
 113
 114 // ****************************************************************************
 115 // write
 116 //
 117 // Write data from buffer into NVRAM.
 118 //
 119 // ****************************************************************************
 120 IOReturn AppleNVRAM::write(IOByteCount offset, UInt8 *buffer,
 121                            IOByteCount length)
 122 {
 123   UInt32 cnt;
 124
 125   // length and offset can't be less than zero (unsigned), so we don't check
 126   if ((buffer == 0) || (length == 0) || (offset + length > kNVRAMImageSize))
 127     return kIOReturnBadArgument;
 128
 129   switch (_nvramType) {
 130   case kNVRAMTypeIOMem :
 131     for (cnt = 0; cnt < length; cnt++) {
 132       _nvramData[(offset + cnt)  << 4] = buffer[cnt];
 133       eieio();
 134     }
 135     break;
 136
 137   case kNVRAMTypePort:
 138     for (cnt = 0; cnt < length; cnt++) {
 139       *_nvramPort = (offset + length) >> 5;
 140       eieio();
 141       _nvramData[((offset + length) & 0x1F) << 4] = buffer[cnt];
 142       eieio();
 143     }
 144     break;
 145
 146   default :
 147     return kIOReturnNotReady;
 148   }
 149
 150   return kIOReturnSuccess;
 151 }