xref: /btstack/src/btstack_hid_parser.h (revision 7dc86dfd3569d69491d87d64749fd45afb46c67a)
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
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
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
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
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
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 /*
39  *  btstack_hid_parser.h
40  *
41  *  Single-pass HID Report Parser: HID Report is directly parsed without preprocessing HID Descriptor to minimize memory
42  */
43 
44 #ifndef __BTSTACK_HID_PARSER_H
45 #define __BTSTACK_HID_PARSER_H
46 
47 #include <stdint.h>
48 
49 #if defined __cplusplus
50 extern "C" {
51 #endif
52 
53 typedef struct  {
54     int32_t  item_value;
55     uint16_t item_size;
56     uint8_t  item_type;
57     uint8_t  item_tag;
58     uint8_t  data_size;
59 } hid_descriptor_item_t;
60 
61 typedef enum {
62     BTSTACK_HID_REPORT_TYPE_OTHER  = 0x0,
63     BTSTACK_HID_REPORT_TYPE_INPUT,
64     BTSTACK_HID_REPORT_TYPE_OUTPUT,
65     BTSTACK_HID_REPORT_TYPE_FEATURE,
66 } btstack_hid_report_type_t;
67 
68 typedef enum {
69     BTSTACK_HID_PARSER_SCAN_FOR_REPORT_ITEM,
70     BTSTACK_HID_PARSER_USAGES_AVAILABLE,
71     BTSTACK_HID_PARSER_COMPLETE,
72 } btstack_hid_parser_state_t;
73 
74 typedef struct {
75 
76     // Descriptor
77     const uint8_t * descriptor;
78     uint16_t        descriptor_len;
79 
80     // Report
81     btstack_hid_report_type_t report_type;
82     const uint8_t * report;
83     uint16_t        report_len;
84 
85     // State
86     btstack_hid_parser_state_t state;
87 
88     hid_descriptor_item_t descriptor_item;
89 
90     uint16_t        descriptor_pos;
91     uint16_t        report_pos_in_bit;
92 
93     // usage pos and usage_page after last main item, used to find next usage
94     uint16_t        usage_pos;
95     uint16_t        usage_page;
96 
97     // usage generator
98     uint32_t        usage_minimum;
99     uint32_t        usage_maximum;
100     uint16_t        available_usages;
101     uint8_t         required_usages;
102     uint8_t         active_record;
103     uint8_t         have_usage_min;
104     uint8_t         have_usage_max;
105 
106     // global
107     int32_t         global_logical_minimum;
108     int32_t         global_logical_maximum;
109     uint16_t        global_usage_page;
110     uint8_t         global_report_size;
111     uint8_t         global_report_count;
112     uint8_t         global_report_id;
113 } btstack_hid_parser_t;
114 
115 /* API_START */
116 
117 /**
118  * @brief Initialize HID Parser.
119  * @param parser state
120  * @param hid_descriptor
121  * @param hid_descriptor_len
122  * @param hid_report_type
123  * @param hid_report
124  * @param hid_report_len
125  */
126 void btstack_hid_parser_init(btstack_hid_parser_t * parser, const uint8_t * hid_descriptor, uint16_t hid_descriptor_len, btstack_hid_report_type_t hid_report_type, const uint8_t * hid_report, uint16_t hid_report_len);
127 
128 /**
129  * @brief Checks if more fields are available
130  * @param parser
131  */
132 int  btstack_hid_parser_has_more(btstack_hid_parser_t * parser);
133 
134 /**
135  * @brief Get next field
136  * @param parser
137  * @param usage_page
138  * @param usage
139  * @param value provided in HID report
140  */
141 void btstack_hid_parser_get_field(btstack_hid_parser_t * parser, uint16_t * usage_page, uint16_t * usage, int32_t * value);
142 
143 /* API_END */
144 
145 #if defined __cplusplus
146 }
147 #endif
148 
149 #endif // __BTSTACK_HID_PARSER_H
150