xref: /btstack/src/btstack_hid_parser.h (revision 077fecbb6ed539507f37505ebd8a5b00e01c55e9)
1 /*
2  * Copyright (C) 2017 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
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7  *
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9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
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15  *    from this software without specific prior written permission.
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19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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36  */
37 
38 /**
39  * @title HID Parser
40  *
41  * Single-pass HID Report Parser: HID Report is directly parsed without preprocessing HID Descriptor to minimize memory.
42  *
43  */
44 
45 #ifndef BTSTACK_HID_PARSER_H
46 #define BTSTACK_HID_PARSER_H
47 
48 #include <stdint.h>
49 #include "btstack_hid.h"
50 
51 #if defined __cplusplus
52 extern "C" {
53 #endif
54 
55 typedef enum {
56     Main=0,
57     Global,
58     Local,
59     Reserved
60 } TagType;
61 
62 typedef enum {
63     Input=8,
64     Output,
65     Coll,
66     Feature,
67     EndColl
68 } MainItemTag;
69 
70 typedef enum {
71     UsagePage,
72     LogicalMinimum,
73     LogicalMaximum,
74     PhysicalMinimum,
75     PhysicalMaximum,
76     UnitExponent,
77     Unit,
78     ReportSize,
79     ReportID,
80     ReportCount,
81     Push,
82     Pop
83 } GlobalItemTag;
84 
85 typedef enum {
86     Usage,
87     UsageMinimum,
88     UsageMaximum,
89     DesignatorIndex,
90     DesignatorMinimum,
91     DesignatorMaximum,
92     StringIndex,
93     StringMinimum,
94     StringMaximum,
95     Delimiter
96 } LocalItemTag;
97 
98 typedef struct  {
99     int32_t  item_value;
100     uint16_t item_size;
101     uint8_t  item_type;
102     uint8_t  item_tag;
103     uint8_t  data_size;
104 } hid_descriptor_item_t;
105 
106 typedef enum {
107     BTSTACK_HID_PARSER_SCAN_FOR_REPORT_ITEM,
108     BTSTACK_HID_PARSER_USAGES_AVAILABLE,
109     BTSTACK_HID_PARSER_COMPLETE,
110 } btstack_hid_parser_state_t;
111 
112 
113 typedef struct {
114 
115     // Descriptor
116     const uint8_t * descriptor;
117     uint16_t        descriptor_len;
118 
119     // Report
120     hid_report_type_t report_type;
121     const uint8_t * report;
122     uint16_t        report_len;
123 
124     // State
125     btstack_hid_parser_state_t state;
126 
127     hid_descriptor_item_t descriptor_item;
128 
129     uint16_t        descriptor_pos;
130     uint16_t        report_pos_in_bit;
131 
132     // usage pos and usage_page after last main item, used to find next usage
133     uint16_t        usage_pos;
134     uint16_t        usage_page;
135 
136     // usage generator
137     uint32_t        usage_minimum;
138     uint32_t        usage_maximum;
139     uint16_t        available_usages;
140     uint8_t         required_usages;
141     uint8_t         active_record;
142     uint8_t         have_usage_min;
143     uint8_t         have_usage_max;
144 
145     // global
146     int32_t         global_logical_minimum;
147     int32_t         global_logical_maximum;
148     uint16_t        global_usage_page;
149     uint8_t         global_report_size;
150     uint8_t         global_report_count;
151     uint8_t         global_report_id;
152 } btstack_hid_parser_t;
153 
154 /* API_START */
155 
156 /**
157  * @brief Initialize HID Parser.
158  * @param parser state
159  * @param hid_descriptor
160  * @param hid_descriptor_len
161  * @param hid_report_type
162  * @param hid_report
163  * @param hid_report_len
164  */
165 void btstack_hid_parser_init(btstack_hid_parser_t * parser, const uint8_t * hid_descriptor, uint16_t hid_descriptor_len, hid_report_type_t hid_report_type, const uint8_t * hid_report, uint16_t hid_report_len);
166 
167 /**
168  * @brief Checks if more fields are available
169  * @param parser
170  */
171 int  btstack_hid_parser_has_more(btstack_hid_parser_t * parser);
172 
173 /**
174  * @brief Get next field
175  * @param parser
176  * @param usage_page
177  * @param usage
178  * @param value provided in HID report
179  */
180 void btstack_hid_parser_get_field(btstack_hid_parser_t * parser, uint16_t * usage_page, uint16_t * usage, int32_t * value);
181 
182 /**
183  * @brief Parses descriptor item
184  * @param item
185  * @param hid_descriptor
186  * @param hid_descriptor_len
187  */
188 void btstack_hid_parse_descriptor_item(hid_descriptor_item_t * item, const uint8_t * hid_descriptor, uint16_t hid_descriptor_len);
189 
190 /**
191  * @brief Parses descriptor and returns report size for given report ID and report type
192  * @param report_id
193  * @param report_type
194  * @param hid_descriptor_len
195  * @param hid_descriptor
196  */
197 int btstack_hid_get_report_size_for_id(int report_id, hid_report_type_t report_type, uint16_t hid_descriptor_len, const uint8_t * hid_descriptor);
198 
199 /**
200  * @brief Parses descriptor and returns report size for given report ID and report type
201  * @param report_id
202  * @param hid_descriptor_len
203  * @param hid_descriptor
204  */
205 hid_report_id_status_t btstack_hid_id_valid(int report_id, uint16_t hid_descriptor_len, const uint8_t * hid_descriptor);
206 
207 /**
208  * @brief Parses descriptor and returns 1 if report ID found
209  * @param hid_descriptor_len
210  * @param hid_descriptor
211  */
212 int btstack_hid_report_id_declared(uint16_t hid_descriptor_len, const uint8_t * hid_descriptor);
213 /* API_END */
214 
215 #if defined __cplusplus
216 }
217 #endif
218 
219 #endif // BTSTACK_HID_PARSER_H
220