iokit/Families/IOHIDSystem/IOHIDDescriptorParser/HIDProcessGlobalItem.c

   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         File:           HIDProcessGlobalItem.c
  24
  25         Contains:       xxx put contents here xxx
  26
  27         Version:        xxx put version here xxx
  28
  29         Copyright:      © 1999 by Apple Computer, Inc., all rights reserved.
  30
  31         File Ownership:
  32
  33                 DRI:                            xxx put dri here xxx
  34
  35                 Other Contact:          xxx put other contact here xxx
  36
  37                 Technology:                     xxx put technology here xxx
  38
  39         Writers:
  40
  41                 (DF)    David Ferguson
  42                 (BWS)   Brent Schorsch
  43
  44         Change History (most recent first):
  45
  46           <USB2>        10/18/99        DF              Lets try not reporting an error with zero report count
  47           <USB1>          3/5/99        BWS             first checked in
  48 */
  49
  50 #include "HIDLib.h"
  51
  52 /*
  53  *------------------------------------------------------------------------------
  54  *
  55  * HIDProcessGlobalItem - Process a GlobalItem
  56  *
  57  *       Input:
  58  *                        ptDescriptor                  - The Descriptor Structure
  59  *                        ptPreparsedData               - The PreParsedData Structure
  60  *       Output:
  61  *                        ptDescriptor                  - The Descriptor Structure
  62  *                        ptPreparsedData               - The PreParsedData Structure
  63  *       Returns:
  64  *                        kHIDSuccess              - Success
  65  *                        kHIDNullPointerErr      - Argument, Pointer was Null
  66  *
  67  *------------------------------------------------------------------------------
  68 */
  69 OSStatus HIDProcessGlobalItem(HIDReportDescriptor *ptDescriptor, HIDPreparsedDataPtr ptPreparsedData)
  70 {
  71         HIDReportSizes *ptReport;
  72         HIDGlobalItems *ptGlobals;
  73         HIDItem *ptItem;
  74         int reportIndex;
  75 /*
  76  *      Disallow NULL Pointers
  77 */
  78         if ((ptDescriptor == NULL) || (ptPreparsedData == NULL))
  79                 return kHIDNullPointerErr;
  80 /*
  81  *      Process by tag
  82 */
  83         ptItem = &ptDescriptor->item;
  84         ptGlobals = &ptDescriptor->globals;
  85         switch (ptItem->tag)
  86         {
  87 /*
  88  *              usage Page
  89 */
  90                 case kHIDTagUsagePage:
  91                         if (ptItem->unsignedValue == 0)
  92                                 return kHIDUsagePageZeroErr;
  93                         ptGlobals->usagePage = ptItem->unsignedValue;
  94                         break;
  95 /*
  96  *              Logical Minimum
  97 */
  98                 case kHIDTagLogicalMinimum:
  99                         ptGlobals->logicalMinimum = ptItem->signedValue;
 100                         break;
 101 /*
 102  *              Logical Maximum
 103 */
 104                 case kHIDTagLogicalMaximum:
 105                         ptGlobals->logicalMaximum = ptItem->signedValue;
 106                         break;
 107 /*
 108  *              Physical Minimum
 109 */
 110                 case kHIDTagPhysicalMinimum:
 111                         ptGlobals->physicalMinimum = ptItem->signedValue;
 112                         break;
 113 /*
 114  *              Physical Maximum
 115 */
 116                 case kHIDTagPhysicalMaximum:
 117                         ptGlobals->physicalMaximum = ptItem->signedValue;
 118                         break;
 119 /*
 120  *              Unit Exponent
 121 */
 122                 case kHIDTagUnitExponent:
 123                         ptGlobals->unitExponent = ptItem->signedValue;
 124                         break;
 125 /*
 126  *              Unit
 127 */
 128                 case kHIDTagUnit:
 129                         ptGlobals->units = ptItem->unsignedValue;
 130                         break;
 131 /*
 132  *              Report Size in Bits
 133 */
 134                 case kHIDTagReportSize:
 135                         ptGlobals->reportSize = ptItem->unsignedValue;
 136                         if (ptGlobals->reportSize == 0)
 137                                 return kHIDReportSizeZeroErr;
 138                         break;
 139 /*
 140  *              Report ID
 141 */
 142                 case kHIDTagReportID:
 143                         if (ptItem->unsignedValue == 0)
 144                                 return kHIDReportIDZeroErr;
 145 /*
 146  *                      Look for the Report ID in the table
 147 */
 148                         reportIndex = 0;
 149                         while ((reportIndex < ptPreparsedData->reportCount)
 150                                 && (ptPreparsedData->reports[reportIndex].reportID != ptItem->unsignedValue))
 151                                 reportIndex++;
 152 /*
 153  *                      Initialize the entry if it's new and there's room for it
 154  *                        Start with 8 bits for the Report ID
 155 */
 156                         if (reportIndex == ptPreparsedData->reportCount)
 157                         {
 158                                 ptReport = &ptPreparsedData->reports[ptPreparsedData->reportCount++];
 159                                 ptReport->reportID = ptItem->unsignedValue;
 160                                 ptReport->inputBitCount = 8;
 161                                 ptReport->outputBitCount = 8;
 162                                 ptReport->featureBitCount = 8;
 163                         }
 164 /*
 165  *                      Remember which report is being processed
 166 */
 167                         ptGlobals->reportID = ptItem->unsignedValue;
 168                         ptGlobals->reportIndex = reportIndex;
 169                         break;
 170 /*
 171  *              Report Count
 172 */
 173                 case kHIDTagReportCount:
 174 #if 0
 175                         // some device actually have a report count of zero specified.  we must allow it!
 176                         if (ptItem->unsignedValue == 0)
 177                                 return kHIDReportCountZeroErr;
 178 #endif
 179                         ptGlobals->reportCount = ptItem->unsignedValue;
 180                         break;
 181 /*
 182  *              Push Globals
 183 */
 184                 case kHIDTagPush:
 185                         ptDescriptor->globalsStack[ptDescriptor->globalsNesting++] = ptDescriptor->globals;
 186                         break;
 187 /*
 188  *              Pop Globals
 189 */
 190                 case kHIDTagPop:
 191                         ptDescriptor->globals = ptDescriptor->globalsStack[--ptDescriptor->globalsNesting];
 192                         break;
 193         }
 194         return kHIDSuccess;
 195 }