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1 | /** @file\r | |
2 | Helper functions to parse HID report descriptor and items.\r | |
3 | \r | |
4 | Copyright (c) 2004 - 2008, Intel Corporation\r | |
5 | All rights reserved. This program and the accompanying materials\r | |
6 | are licensed and made available under the terms and conditions of the BSD License\r | |
7 | which accompanies this distribution. The full text of the license may be found at\r | |
8 | http://opensource.org/licenses/bsd-license.php\r | |
9 | \r | |
10 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
11 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
12 | \r | |
13 | **/\r | |
14 | \r | |
15 | #include "UsbMouseAbsolutePointer.h"\r | |
16 | \r | |
17 | \r | |
18 | /**\r | |
19 | Get next HID item from report descriptor.\r | |
20 | \r | |
21 | This function retrieves next HID item from report descriptor, according to\r | |
22 | the start position.\r | |
23 | According to USB HID Specification, An item is piece of information\r | |
24 | about the device. All items have a one-byte prefix that contains\r | |
25 | the item tag, item type, and item size.\r | |
26 | There are two basic types of items: short items and long items.\r | |
27 | If the item is a short item, its optional data size may be 0, 1, 2, or 4 bytes.\r | |
28 | Only short item is supported here.\r | |
29 | \r | |
30 | @param StartPos Start position of the HID item to get.\r | |
31 | @param EndPos End position of the range to get the the next HID item.\r | |
32 | @param HidItem Buffer for the HID Item to return.\r | |
33 | \r | |
34 | @return Pointer to end of the HID item returned.\r | |
35 | NULL if no HID item retrieved.\r | |
36 | \r | |
37 | **/\r | |
38 | UINT8 *\r | |
39 | GetNextHidItem (\r | |
40 | IN UINT8 *StartPos,\r | |
41 | IN UINT8 *EndPos,\r | |
42 | OUT HID_ITEM *HidItem\r | |
43 | )\r | |
44 | {\r | |
45 | UINT8 Temp;\r | |
46 | \r | |
47 | if (EndPos <= StartPos) {\r | |
48 | return NULL;\r | |
49 | }\r | |
50 | \r | |
51 | Temp = *StartPos;\r | |
52 | StartPos++;\r | |
53 | \r | |
54 | //\r | |
55 | // Bit format of prefix byte:\r | |
56 | // Bits 0-1: Size\r | |
57 | // Bits 2-3: Type\r | |
58 | // Bits 4-7: Tag\r | |
59 | //\r | |
60 | HidItem->Type = BitFieldRead8 (Temp, 2, 3);\r | |
61 | HidItem->Tag = BitFieldRead8 (Temp, 4, 7);\r | |
62 | \r | |
63 | if (HidItem->Tag == HID_ITEM_TAG_LONG) {\r | |
64 | //\r | |
65 | // Long Items are not supported, although we try to parse it.\r | |
66 | //\r | |
67 | HidItem->Format = HID_ITEM_FORMAT_LONG;\r | |
68 | \r | |
69 | if ((EndPos - StartPos) >= 2) {\r | |
70 | HidItem->Size = *StartPos++;\r | |
71 | HidItem->Tag = *StartPos++;\r | |
72 | \r | |
73 | if ((EndPos - StartPos) >= HidItem->Size) {\r | |
74 | HidItem->Data.LongData = StartPos;\r | |
75 | StartPos += HidItem->Size;\r | |
76 | return StartPos;\r | |
77 | }\r | |
78 | }\r | |
79 | } else {\r | |
80 | HidItem->Format = HID_ITEM_FORMAT_SHORT;\r | |
81 | HidItem->Size = BitFieldRead8 (Temp, 0, 1);\r | |
82 | \r | |
83 | switch (HidItem->Size) {\r | |
84 | case 0:\r | |
85 | //\r | |
86 | // No data\r | |
87 | //\r | |
88 | return StartPos;\r | |
89 | \r | |
90 | case 1:\r | |
91 | //\r | |
92 | // 1-byte data\r | |
93 | //\r | |
94 | if ((EndPos - StartPos) >= 1) {\r | |
95 | HidItem->Data.U8 = *StartPos++;\r | |
96 | return StartPos;\r | |
97 | }\r | |
98 | \r | |
99 | case 2:\r | |
100 | //\r | |
101 | // 2-byte data\r | |
102 | //\r | |
103 | if ((EndPos - StartPos) >= 2) {\r | |
104 | CopyMem (&HidItem->Data.U16, StartPos, sizeof (UINT16));\r | |
105 | StartPos += 2;\r | |
106 | return StartPos;\r | |
107 | }\r | |
108 | \r | |
109 | case 3:\r | |
110 | //\r | |
111 | // 4-byte data, adjust size\r | |
112 | //\r | |
113 | HidItem->Size = 4;\r | |
114 | if ((EndPos - StartPos) >= 4) {\r | |
115 | CopyMem (&HidItem->Data.U32, StartPos, sizeof (UINT32));\r | |
116 | StartPos += 4;\r | |
117 | return StartPos;\r | |
118 | }\r | |
119 | }\r | |
120 | }\r | |
121 | \r | |
122 | return NULL;\r | |
123 | }\r | |
124 | \r | |
125 | \r | |
126 | /**\r | |
127 | Get data from HID item.\r | |
128 | \r | |
129 | This function retrieves data from HID item.\r | |
130 | It only supports short items, which has 4 types of data:\r | |
131 | 0, 1, 2, or 4 bytes.\r | |
132 | \r | |
133 | @param HidItem Pointer to the HID item.\r | |
134 | \r | |
135 | @return The data of HID item.\r | |
136 | \r | |
137 | **/\r | |
138 | UINT32\r | |
139 | GetItemData (\r | |
140 | IN HID_ITEM *HidItem\r | |
141 | )\r | |
142 | {\r | |
143 | //\r | |
144 | // Get data from HID item.\r | |
145 | //\r | |
146 | switch (HidItem->Size) {\r | |
147 | case 1:\r | |
148 | return HidItem->Data.U8;\r | |
149 | case 2:\r | |
150 | return HidItem->Data.U16;\r | |
151 | case 4:\r | |
152 | return HidItem->Data.U32;\r | |
153 | }\r | |
154 | return 0;\r | |
155 | }\r | |
156 | \r | |
157 | /**\r | |
158 | Parse HID item from report descriptor.\r | |
159 | \r | |
160 | There are three item types: Main, Global, and Local.\r | |
161 | This function parses these types of HID items according\r | |
162 | to tag info.\r | |
163 | \r | |
164 | @param UsbMouse The instance of USB_MOUSE_ABSOLUTE_POINTER_DEV\r | |
165 | @param HidItem The HID item to parse\r | |
166 | \r | |
167 | **/\r | |
168 | VOID\r | |
169 | ParseHidItem (\r | |
170 | IN USB_MOUSE_ABSOLUTE_POINTER_DEV *UsbMouse,\r | |
171 | IN HID_ITEM *HidItem\r | |
172 | )\r | |
173 | {\r | |
174 | UINT8 Data;\r | |
175 | \r | |
176 | switch (HidItem->Type) {\r | |
177 | \r | |
178 | case HID_ITEM_TYPE_MAIN:\r | |
179 | //\r | |
180 | // we don't care any main items, just skip\r | |
181 | //\r | |
182 | return ;\r | |
183 | \r | |
184 | case HID_ITEM_TYPE_GLOBAL:\r | |
185 | //\r | |
186 | // For global items, we only care Usage Page tag for Button Page here\r | |
187 | //\r | |
188 | if (HidItem->Tag == HID_GLOBAL_ITEM_TAG_USAGE_PAGE) {\r | |
189 | Data = (UINT8) GetItemData (HidItem);\r | |
190 | if (Data == 0x09) {\r | |
191 | //\r | |
192 | // Button Page\r | |
193 | //\r | |
194 | UsbMouse->PrivateData.ButtonDetected = TRUE;\r | |
195 | }\r | |
196 | }\r | |
197 | return;\r | |
198 | \r | |
199 | case HID_ITEM_TYPE_LOCAL:\r | |
200 | if (HidItem->Size == 0) {\r | |
201 | //\r | |
202 | // No expected data for local item\r | |
203 | //\r | |
204 | return ;\r | |
205 | }\r | |
206 | \r | |
207 | Data = (UINT8) GetItemData (HidItem);\r | |
208 | \r | |
209 | switch (HidItem->Tag) {\r | |
210 | case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:\r | |
211 | if (UsbMouse->PrivateData.ButtonDetected) {\r | |
212 | UsbMouse->PrivateData.ButtonMinIndex = Data;\r | |
213 | }\r | |
214 | return ;\r | |
215 | \r | |
216 | case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:\r | |
217 | {\r | |
218 | if (UsbMouse->PrivateData.ButtonDetected) {\r | |
219 | UsbMouse->PrivateData.ButtonMaxIndex = Data;\r | |
220 | }\r | |
221 | return ;\r | |
222 | }\r | |
223 | \r | |
224 | default:\r | |
225 | return ;\r | |
226 | }\r | |
227 | }\r | |
228 | }\r | |
229 | \r | |
230 | \r | |
231 | /**\r | |
232 | Parse Mouse Report Descriptor.\r | |
233 | \r | |
234 | According to USB HID Specification, report descriptors are\r | |
235 | composed of pieces of information. Each piece of information\r | |
236 | is called an Item. This function retrieves each item from\r | |
237 | the report descriptor and updates USB_MOUSE_ABSOLUTE_POINTER_DEV.\r | |
238 | \r | |
239 | @param UsbMouseAbsolutePointer The instance of USB_MOUSE_ABSOLUTE_POINTER_DEV\r | |
240 | @param ReportDescriptor Report descriptor to parse\r | |
241 | @param ReportSize Report descriptor size\r | |
242 | \r | |
243 | @retval EFI_SUCCESS Report descriptor successfully parsed.\r | |
244 | @retval EFI_UNSUPPORTED Report descriptor contains long item.\r | |
245 | \r | |
246 | **/\r | |
247 | EFI_STATUS\r | |
248 | ParseMouseReportDescriptor (\r | |
249 | OUT USB_MOUSE_ABSOLUTE_POINTER_DEV *UsbMouseAbsolutePointer,\r | |
250 | IN UINT8 *ReportDescriptor,\r | |
251 | IN UINTN ReportSize\r | |
252 | )\r | |
253 | {\r | |
254 | UINT8 *DescriptorEnd;\r | |
255 | UINT8 *Ptr;\r | |
256 | HID_ITEM HidItem;\r | |
257 | \r | |
258 | DescriptorEnd = ReportDescriptor + ReportSize;\r | |
259 | \r | |
260 | Ptr = GetNextHidItem (ReportDescriptor, DescriptorEnd, &HidItem);\r | |
261 | while (Ptr != NULL) {\r | |
262 | if (HidItem.Format != HID_ITEM_FORMAT_SHORT) {\r | |
263 | //\r | |
264 | // Long Item is not supported at current HID revision\r | |
265 | //\r | |
266 | return EFI_UNSUPPORTED;\r | |
267 | }\r | |
268 | \r | |
269 | ParseHidItem (UsbMouseAbsolutePointer, &HidItem);\r | |
270 | \r | |
271 | Ptr = GetNextHidItem (Ptr, DescriptorEnd, &HidItem);\r | |
272 | }\r | |
273 | \r | |
274 | UsbMouseAbsolutePointer->NumberOfButtons = (UINT8) (UsbMouseAbsolutePointer->PrivateData.ButtonMaxIndex - UsbMouseAbsolutePointer->PrivateData.ButtonMinIndex + 1);\r | |
275 | UsbMouseAbsolutePointer->XLogicMax = 1023;\r | |
276 | UsbMouseAbsolutePointer->YLogicMax = 1023;\r | |
277 | UsbMouseAbsolutePointer->XLogicMin = -1023;\r | |
278 | UsbMouseAbsolutePointer->YLogicMin = -1023;\r | |
279 | \r | |
280 | return EFI_SUCCESS;\r | |
281 | }\r |