1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef DEVICE_HID_HID_REPORT_DESCRIPTOR_ITEM_H_ 6 #define DEVICE_HID_HID_REPORT_DESCRIPTOR_ITEM_H_ 7 8 #include "base/basictypes.h" 9 10 namespace device { 11 12 // An element of a HID report descriptor. 13 class HidReportDescriptorItem { 14 private: 15 friend class HidReportDescriptor; 16 17 enum Type { 18 kTypeMain = 0, 19 kTypeGlobal = 1, 20 kTypeLocal = 2, 21 kTypeReserved = 3 22 }; 23 24 enum MainTag { 25 kMainTagDefault = 0x00, // 0000 26 kMainTagInput = 0x08, // 1000 27 kMainTagOutput = 0x09, // 1001 28 kMainTagFeature = 0x0B, // 1011 29 kMainTagCollection = 0x0A, // 1010 30 kMainTagEndCollection = 0x0C // 1100 31 }; 32 33 enum GlobalTag { 34 kGlobalTagUsagePage = 0x00, // 0000 35 kGlobalTagLogicalMinimum = 0x01, // 0001 36 kGlobalTagLogicalMaximum = 0x02, // 0010 37 kGlobalTagPhysicalMinimum = 0x03, // 0011 38 kGlobalTagPhysicalMaximum = 0x04, // 0100 39 kGlobalTagUnitExponent = 0x05, // 0101 40 kGlobalTagUnit = 0x06, // 0110 41 kGlobalTagReportSize = 0x07, // 0111 42 kGlobalTagReportId = 0x08, // 1000 43 kGlobalTagReportCount = 0x09, // 1001 44 kGlobalTagPush = 0x0A, // 1010 45 kGlobalTagPop = 0x0B // 1011 46 }; 47 48 enum LocalTag { 49 kLocalTagUsage = 0x00, // 0000 50 kLocalTagUsageMinimum = 0x01, // 0001 51 kLocalTagUsageMaximum = 0x02, // 0010 52 kLocalTagDesignatorIndex = 0x03, // 0011 53 kLocalTagDesignatorMinimum = 0x04, // 0100 54 kLocalTagDesignatorMaximum = 0x05, // 0101 55 kLocalTagStringIndex = 0x07, // 0111 56 kLocalTagStringMinimum = 0x08, // 1000 57 kLocalTagStringMaximum = 0x09, // 1001 58 kLocalTagDelimiter = 0x0A // 1010 59 }; 60 61 enum ReservedTag { 62 kReservedTagLong = 0xF // 1111 63 }; 64 65 public: 66 enum Tag { 67 kTagDefault = kMainTagDefault << 2 | kTypeMain, 68 kTagInput = kMainTagInput << 2 | kTypeMain, 69 kTagOutput = kMainTagOutput << 2 | kTypeMain, 70 kTagFeature = kMainTagFeature << 2 | kTypeMain, 71 kTagCollection = kMainTagCollection << 2 | kTypeMain, 72 kTagEndCollection = kMainTagEndCollection << 2 | kTypeMain, 73 kTagUsagePage = kGlobalTagUsagePage << 2 | kTypeGlobal, 74 kTagLogicalMinimum = kGlobalTagLogicalMinimum << 2 | kTypeGlobal, 75 kTagLogicalMaximum = kGlobalTagLogicalMaximum << 2 | kTypeGlobal, 76 kTagPhysicalMinimum = kGlobalTagPhysicalMinimum << 2 | kTypeGlobal, 77 kTagPhysicalMaximum = kGlobalTagPhysicalMaximum << 2 | kTypeGlobal, 78 kTagUnitExponent = kGlobalTagUnitExponent << 2 | kTypeGlobal, 79 kTagUnit = kGlobalTagUnit << 2 | kTypeGlobal, 80 kTagReportSize = kGlobalTagReportSize << 2 | kTypeGlobal, 81 kTagReportId = kGlobalTagReportId << 2 | kTypeGlobal, 82 kTagReportCount = kGlobalTagReportCount << 2 | kTypeGlobal, 83 kTagPush = kGlobalTagPush << 2 | kTypeGlobal, 84 kTagPop = kGlobalTagPop << 2 | kTypeGlobal, 85 kTagUsage = kLocalTagUsage << 2 | kTypeLocal, 86 kTagUsageMinimum = kLocalTagUsageMinimum << 2 | kTypeLocal, 87 kTagUsageMaximum = kLocalTagUsageMaximum << 2 | kTypeLocal, 88 kTagDesignatorIndex = kLocalTagDesignatorIndex << 2 | kTypeLocal, 89 kTagDesignatorMinimum = kLocalTagDesignatorMinimum << 2 | kTypeLocal, 90 kTagDesignatorMaximum = kLocalTagDesignatorMaximum << 2 | kTypeLocal, 91 kTagStringIndex = kLocalTagStringIndex << 2 | kTypeLocal, 92 kTagStringMinimum = kLocalTagStringMinimum << 2 | kTypeLocal, 93 kTagStringMaximum = kLocalTagStringMaximum << 2 | kTypeLocal, 94 kTagDelimiter = kLocalTagDelimiter << 2 | kTypeLocal, 95 kTagLong = kReservedTagLong << 2 | kTypeReserved 96 }; 97 98 // HID Input/Output/Feature report information. 99 // Can be retrieved from GetShortData() 100 // when item.tag() == HidReportDescriptorItem::kTagInput 101 // or HidReportDescriptorItem::kTagOutput 102 // or HidReportDescriptorItem::kTagFeature 103 struct ReportInfo { 104 uint8_t data_or_constant : 1; 105 uint8_t array_or_variable : 1; 106 uint8_t absolute_or_relative : 1; 107 uint8_t wrap : 1; 108 uint8_t linear : 1; 109 uint8_t preferred : 1; 110 uint8_t null : 1; 111 uint8_t reserved_1 : 1; 112 uint8_t bit_field_or_buffer : 1; 113 uint8_t reserved_2 : 1; 114 }; 115 116 // HID collection type. 117 // Can be retrieved from GetShortData() 118 // when item.tag() == HidReportDescriptorItem::kTagCollection 119 enum CollectionType { 120 kCollectionTypePhysical, 121 kCollectionTypeApplication, 122 kCollectionTypeLogical, 123 kCollectionTypeReport, 124 kCollectionTypeNamedArray, 125 kCollectionTypeUsageSwitch, 126 kCollectionTypeUsageModifier, 127 kCollectionTypeReserved, 128 kCollectionTypeVendor 129 }; 130 131 private: 132 HidReportDescriptorItem(const uint8_t* bytes, 133 HidReportDescriptorItem* previous); 134 135 public: 136 ~HidReportDescriptorItem() {} 137 138 // Previous element in report descriptor. 139 // Owned by descriptor instance. 140 HidReportDescriptorItem* previous() const { 141 return previous_; 142 }; 143 // Next element in report descriptor. 144 // Owned by descriptor instance. 145 HidReportDescriptorItem* next() const { 146 return next_; 147 }; 148 // Parent element in report descriptor. 149 // Owned by descriptor instance. 150 // Can be NULL. 151 HidReportDescriptorItem* parent() const { 152 return parent_; 153 }; 154 // Level in Parent-Children relationship tree. 155 // 0 for top-level items (parent()==NULL). 156 // 1 if parent() is top-level. 157 // 2 if parent() has a top-level parent. Etc. 158 size_t GetDepth() const; 159 Tag tag() const { return tag_; } 160 // Returns true for a long item, false otherwise. 161 bool IsLong() const; 162 // Raw data of a short item. 163 // Not valid for a long item. 164 uint32_t GetShortData() const; 165 166 static CollectionType GetCollectionTypeFromValue(uint32_t value); 167 168 private: 169 size_t GetHeaderSize() const; 170 size_t payload_size() const { return payload_size_; } 171 size_t GetSize() const; 172 173 HidReportDescriptorItem* previous_; 174 HidReportDescriptorItem* next_; 175 HidReportDescriptorItem* parent_; 176 Tag tag_; 177 uint32_t shortData_; 178 size_t payload_size_; 179 }; 180 181 } // namespace device 182 183 #endif // DEVICE_HID_HID_REPORT_DESCRIPTOR_ITEM_H_ 184
