xref: /btstack/src/btstack_hid_parser.c (revision 1a05cde17523aeefa494ec53fab09148bf6f7a2e)
112ccb71bSMatthias Ringwald /*
212ccb71bSMatthias Ringwald  * Copyright (C) 2017 BlueKitchen GmbH
312ccb71bSMatthias Ringwald  *
412ccb71bSMatthias Ringwald  * Redistribution and use in source and binary forms, with or without
512ccb71bSMatthias Ringwald  * modification, are permitted provided that the following conditions
612ccb71bSMatthias Ringwald  * are met:
712ccb71bSMatthias Ringwald  *
812ccb71bSMatthias Ringwald  * 1. Redistributions of source code must retain the above copyright
912ccb71bSMatthias Ringwald  *    notice, this list of conditions and the following disclaimer.
1012ccb71bSMatthias Ringwald  * 2. Redistributions in binary form must reproduce the above copyright
1112ccb71bSMatthias Ringwald  *    notice, this list of conditions and the following disclaimer in the
1212ccb71bSMatthias Ringwald  *    documentation and/or other materials provided with the distribution.
1312ccb71bSMatthias Ringwald  * 3. Neither the name of the copyright holders nor the names of
1412ccb71bSMatthias Ringwald  *    contributors may be used to endorse or promote products derived
1512ccb71bSMatthias Ringwald  *    from this software without specific prior written permission.
1612ccb71bSMatthias Ringwald  * 4. Any redistribution, use, or modification is done solely for
1712ccb71bSMatthias Ringwald  *    personal benefit and not for any commercial purpose or for
1812ccb71bSMatthias Ringwald  *    monetary gain.
1912ccb71bSMatthias Ringwald  *
2012ccb71bSMatthias Ringwald  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
2112ccb71bSMatthias Ringwald  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
2212ccb71bSMatthias Ringwald  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
232fca4dadSMilanka Ringwald  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN
242fca4dadSMilanka Ringwald  * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
2512ccb71bSMatthias Ringwald  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
2612ccb71bSMatthias Ringwald  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
2712ccb71bSMatthias Ringwald  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
2812ccb71bSMatthias Ringwald  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
2912ccb71bSMatthias Ringwald  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
3012ccb71bSMatthias Ringwald  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
3112ccb71bSMatthias Ringwald  * SUCH DAMAGE.
3212ccb71bSMatthias Ringwald  *
3312ccb71bSMatthias Ringwald  * Please inquire about commercial licensing options at
3412ccb71bSMatthias Ringwald  * [email protected]
3512ccb71bSMatthias Ringwald  *
3612ccb71bSMatthias Ringwald  */
3712ccb71bSMatthias Ringwald 
38e501bae0SMatthias Ringwald #define BTSTACK_FILE__ "btstack_hid_parser.c"
3912ccb71bSMatthias Ringwald 
40*1a05cde1SMatthias Ringwald #define ENABLE_LOG_DEBUG
41*1a05cde1SMatthias Ringwald 
4212ccb71bSMatthias Ringwald #include <string.h>
4312ccb71bSMatthias Ringwald 
4412ccb71bSMatthias Ringwald #include "btstack_hid_parser.h"
4512ccb71bSMatthias Ringwald #include "btstack_util.h"
4612ccb71bSMatthias Ringwald #include "btstack_debug.h"
4712ccb71bSMatthias Ringwald 
4812ccb71bSMatthias Ringwald // Not implemented:
4912ccb71bSMatthias Ringwald // - Support for Push/Pop
5012ccb71bSMatthias Ringwald // - Optional Pretty Print of HID Descripor
5112ccb71bSMatthias Ringwald // - Support to query descriptort for contained usages, e.g. to detect keyboard or mouse
5212ccb71bSMatthias Ringwald 
5312ccb71bSMatthias Ringwald // #define HID_PARSER_PRETTY_PRINT
5412ccb71bSMatthias Ringwald 
5512ccb71bSMatthias Ringwald /*
5612ccb71bSMatthias Ringwald  *  btstack_hid_parser.c
5712ccb71bSMatthias Ringwald  */
5812ccb71bSMatthias Ringwald 
5912ccb71bSMatthias Ringwald #ifdef HID_PARSER_PRETTY_PRINT
6012ccb71bSMatthias Ringwald 
6112ccb71bSMatthias Ringwald static const char * type_names[] = {
6212ccb71bSMatthias Ringwald     "Main",
6312ccb71bSMatthias Ringwald     "Global",
6412ccb71bSMatthias Ringwald     "Local",
6512ccb71bSMatthias Ringwald     "Reserved"
6612ccb71bSMatthias Ringwald };
6712ccb71bSMatthias Ringwald static const char * main_tags[] = {
6812ccb71bSMatthias Ringwald     "",
6912ccb71bSMatthias Ringwald     "",
7012ccb71bSMatthias Ringwald     "",
7112ccb71bSMatthias Ringwald     "",
7212ccb71bSMatthias Ringwald     "",
7312ccb71bSMatthias Ringwald     "",
7412ccb71bSMatthias Ringwald     "",
7512ccb71bSMatthias Ringwald     "",
7612ccb71bSMatthias Ringwald     "Input ",
7712ccb71bSMatthias Ringwald     "Output",
7812ccb71bSMatthias Ringwald     "Collection",
7912ccb71bSMatthias Ringwald     "Feature",
8012ccb71bSMatthias Ringwald     "End Collection",
8112ccb71bSMatthias Ringwald     "Reserved",
8212ccb71bSMatthias Ringwald     "Reserved",
8312ccb71bSMatthias Ringwald     "Reserved"
8412ccb71bSMatthias Ringwald };
8512ccb71bSMatthias Ringwald static const char * global_tags[] = {
8612ccb71bSMatthias Ringwald     "Usage Page",
8712ccb71bSMatthias Ringwald     "Logical Minimum",
8812ccb71bSMatthias Ringwald     "Logical Maximum",
8912ccb71bSMatthias Ringwald     "Physical Minimum",
9012ccb71bSMatthias Ringwald     "Physical Maximum",
9112ccb71bSMatthias Ringwald     "Unit Exponent",
9212ccb71bSMatthias Ringwald     "Unit",
9312ccb71bSMatthias Ringwald     "Report Size",
9412ccb71bSMatthias Ringwald     "Report ID",
9512ccb71bSMatthias Ringwald     "Report Count",
9612ccb71bSMatthias Ringwald     "Push",
9712ccb71bSMatthias Ringwald     "Pop",
9812ccb71bSMatthias Ringwald     "Reserved",
9912ccb71bSMatthias Ringwald     "Reserved",
10012ccb71bSMatthias Ringwald     "Reserved",
10112ccb71bSMatthias Ringwald     "Reserved"
10212ccb71bSMatthias Ringwald };
10312ccb71bSMatthias Ringwald static const char * local_tags[] = {
10412ccb71bSMatthias Ringwald     "Usage",
10512ccb71bSMatthias Ringwald     "Usage Minimum",
10612ccb71bSMatthias Ringwald     "Usage Maximum",
10712ccb71bSMatthias Ringwald     "Designator Index",
10812ccb71bSMatthias Ringwald     "Designator Minimum",
10912ccb71bSMatthias Ringwald     "Designator Maximum",
11012ccb71bSMatthias Ringwald     "String Index",
11112ccb71bSMatthias Ringwald     "String Minimum",
11212ccb71bSMatthias Ringwald     "String Maximum",
11312ccb71bSMatthias Ringwald     "Delimiter",
11412ccb71bSMatthias Ringwald     "Reserved",
11512ccb71bSMatthias Ringwald     "Reserved",
11612ccb71bSMatthias Ringwald     "Reserved",
11712ccb71bSMatthias Ringwald     "Reserved",
11812ccb71bSMatthias Ringwald     "Reserved",
11912ccb71bSMatthias Ringwald     "Reserved"
12012ccb71bSMatthias Ringwald };
12112ccb71bSMatthias Ringwald #endif
12212ccb71bSMatthias Ringwald 
12312ccb71bSMatthias Ringwald static void hid_pretty_print_item(btstack_hid_parser_t * parser, hid_descriptor_item_t * item){
12412ccb71bSMatthias Ringwald #ifdef HID_PARSER_PRETTY_PRINT
12512ccb71bSMatthias Ringwald     const char ** item_tag_table;
1267bbeb3adSMilanka Ringwald     switch ((TagType)item->item_type){
12712ccb71bSMatthias Ringwald         case Main:
12812ccb71bSMatthias Ringwald             item_tag_table = main_tags;
12912ccb71bSMatthias Ringwald             break;
13012ccb71bSMatthias Ringwald         case Global:
13112ccb71bSMatthias Ringwald             item_tag_table = global_tags;
13212ccb71bSMatthias Ringwald             break;
13312ccb71bSMatthias Ringwald         case Local:
13412ccb71bSMatthias Ringwald             item_tag_table = local_tags;
13512ccb71bSMatthias Ringwald             break;
13612ccb71bSMatthias Ringwald         default:
13712ccb71bSMatthias Ringwald             item_tag_table = NULL;
13812ccb71bSMatthias Ringwald             break;
13912ccb71bSMatthias Ringwald     }
14012ccb71bSMatthias Ringwald     const char * item_tag_name = "Invalid";
14112ccb71bSMatthias Ringwald     if (item_tag_table){
14212ccb71bSMatthias Ringwald         item_tag_name = item_tag_table[item->item_tag];
14312ccb71bSMatthias Ringwald     }
144ea1e21c2SMatthias Ringwald     log_info("%-15s (%-6s) // %02x 0x%0008x", item_tag_name, type_names[item->item_type], parser->descriptor[parser->descriptor_pos], item->item_value);
14512ccb71bSMatthias Ringwald #else
14612ccb71bSMatthias Ringwald     UNUSED(parser);
14712ccb71bSMatthias Ringwald     UNUSED(item);
14812ccb71bSMatthias Ringwald #endif
14912ccb71bSMatthias Ringwald }
15012ccb71bSMatthias Ringwald 
15112ccb71bSMatthias Ringwald // parse descriptor item and read up to 32-bit bit value
152fada7179SMilanka Ringwald void btstack_hid_parse_descriptor_item(hid_descriptor_item_t * item, const uint8_t * hid_descriptor, uint16_t hid_descriptor_len){
1538334d3d8SMatthias Ringwald 
1548334d3d8SMatthias Ringwald     const int hid_item_sizes[] = { 0, 1, 2, 4 };
1558334d3d8SMatthias Ringwald 
15612ccb71bSMatthias Ringwald     // parse item header
1574ea43905SMatthias Ringwald     if (hid_descriptor_len < 1u) return;
15812ccb71bSMatthias Ringwald     uint16_t pos = 0;
15912ccb71bSMatthias Ringwald     uint8_t item_header = hid_descriptor[pos++];
1604ea43905SMatthias Ringwald     item->data_size = hid_item_sizes[item_header & 0x03u];
1614ea43905SMatthias Ringwald     item->item_type = (item_header & 0x0cu) >> 2u;
1624ea43905SMatthias Ringwald     item->item_tag  = (item_header & 0xf0u) >> 4u;
16312ccb71bSMatthias Ringwald     // long item
1644ea43905SMatthias Ringwald     if ((item->data_size == 2u) && (item->item_tag == 0x0fu) && (item->item_type == 3u)){
1654ea43905SMatthias Ringwald         if (hid_descriptor_len < 3u) return;
16612ccb71bSMatthias Ringwald         item->data_size = hid_descriptor[pos++];
16712ccb71bSMatthias Ringwald         item->item_tag  = hid_descriptor[pos++];
16812ccb71bSMatthias Ringwald     }
16912ccb71bSMatthias Ringwald     item->item_size =  pos + item->data_size;
17012ccb71bSMatthias Ringwald     item->item_value = 0;
17112ccb71bSMatthias Ringwald 
17212ccb71bSMatthias Ringwald     // read item value
17312ccb71bSMatthias Ringwald     if (hid_descriptor_len < item->item_size) return;
1744ea43905SMatthias Ringwald     if (item->data_size > 4u) return;
17512ccb71bSMatthias Ringwald     int i;
1764ea43905SMatthias Ringwald     int sgnd = (item->item_type == Global) && (item->item_tag > 0u) && (item->item_tag < 5u);
17712ccb71bSMatthias Ringwald     int32_t value = 0;
17812ccb71bSMatthias Ringwald     uint8_t latest_byte = 0;
17912ccb71bSMatthias Ringwald     for (i=0;i<item->data_size;i++){
18012ccb71bSMatthias Ringwald         latest_byte = hid_descriptor[pos++];
18112ccb71bSMatthias Ringwald         value = (latest_byte << (8*i)) | value;
18212ccb71bSMatthias Ringwald     }
1834ea43905SMatthias Ringwald     if (sgnd && (item->data_size > 0u)){
1844ea43905SMatthias Ringwald         if (latest_byte & 0x80u) {
1854ea43905SMatthias Ringwald             value -= 1u << (item->data_size*8u);
18612ccb71bSMatthias Ringwald         }
18712ccb71bSMatthias Ringwald     }
18812ccb71bSMatthias Ringwald     item->item_value = value;
18912ccb71bSMatthias Ringwald }
19012ccb71bSMatthias Ringwald 
19112ccb71bSMatthias Ringwald static void btstack_hid_handle_global_item(btstack_hid_parser_t * parser, hid_descriptor_item_t * item){
1927bbeb3adSMilanka Ringwald     switch((GlobalItemTag)item->item_tag){
19312ccb71bSMatthias Ringwald         case UsagePage:
19412ccb71bSMatthias Ringwald             parser->global_usage_page = item->item_value;
19512ccb71bSMatthias Ringwald             break;
19612ccb71bSMatthias Ringwald         case LogicalMinimum:
19712ccb71bSMatthias Ringwald             parser->global_logical_minimum = item->item_value;
19812ccb71bSMatthias Ringwald             break;
19912ccb71bSMatthias Ringwald         case LogicalMaximum:
20012ccb71bSMatthias Ringwald             parser->global_logical_maximum = item->item_value;
20112ccb71bSMatthias Ringwald             break;
20212ccb71bSMatthias Ringwald         case ReportSize:
20312ccb71bSMatthias Ringwald             parser->global_report_size = item->item_value;
20412ccb71bSMatthias Ringwald             break;
20512ccb71bSMatthias Ringwald         case ReportID:
206c1ab6cc1SMatthias Ringwald             if (parser->active_record && (parser->global_report_id != item->item_value)){
20712ccb71bSMatthias Ringwald                 parser->active_record = 0;
20812ccb71bSMatthias Ringwald             }
20912ccb71bSMatthias Ringwald             parser->global_report_id = item->item_value;
21012ccb71bSMatthias Ringwald             break;
21112ccb71bSMatthias Ringwald         case ReportCount:
21212ccb71bSMatthias Ringwald             parser->global_report_count = item->item_value;
21312ccb71bSMatthias Ringwald             break;
2147bbeb3adSMilanka Ringwald 
2157bbeb3adSMilanka Ringwald         // TODO handle tags
2167bbeb3adSMilanka Ringwald         case PhysicalMinimum:
2177bbeb3adSMilanka Ringwald         case PhysicalMaximum:
2187bbeb3adSMilanka Ringwald         case UnitExponent:
2197bbeb3adSMilanka Ringwald         case Unit:
2207bbeb3adSMilanka Ringwald         case Push:
2217bbeb3adSMilanka Ringwald         case Pop:
2227bbeb3adSMilanka Ringwald             break;
2237bbeb3adSMilanka Ringwald 
22412ccb71bSMatthias Ringwald         default:
2257bbeb3adSMilanka Ringwald             btstack_assert(false);
22612ccb71bSMatthias Ringwald             break;
22712ccb71bSMatthias Ringwald     }
22812ccb71bSMatthias Ringwald }
22912ccb71bSMatthias Ringwald 
23012ccb71bSMatthias Ringwald static void hid_find_next_usage(btstack_hid_parser_t * parser){
231*1a05cde1SMatthias Ringwald     bool have_usage_min = false;
232*1a05cde1SMatthias Ringwald     bool have_usage_max = false;
233*1a05cde1SMatthias Ringwald     parser->usage_range = false;
2344ea43905SMatthias Ringwald     while ((parser->available_usages == 0u) && (parser->usage_pos < parser->descriptor_pos)){
23512ccb71bSMatthias Ringwald         hid_descriptor_item_t usage_item;
23612ccb71bSMatthias Ringwald         // parser->usage_pos < parser->descriptor_pos < parser->descriptor_len
23712ccb71bSMatthias Ringwald         btstack_hid_parse_descriptor_item(&usage_item, &parser->descriptor[parser->usage_pos], parser->descriptor_len - parser->usage_pos);
2380e588213SMatthias Ringwald         if ((usage_item.item_type == Global) && (usage_item.item_tag == UsagePage)){
23912ccb71bSMatthias Ringwald             parser->usage_page = usage_item.item_value;
24012ccb71bSMatthias Ringwald         }
24112ccb71bSMatthias Ringwald         if (usage_item.item_type == Local){
2424ea43905SMatthias Ringwald             uint32_t usage_value = (usage_item.data_size > 2u) ? usage_item.item_value : ((parser->usage_page << 16u) | usage_item.item_value);
24312ccb71bSMatthias Ringwald             switch (usage_item.item_tag){
24412ccb71bSMatthias Ringwald                 case Usage:
24512ccb71bSMatthias Ringwald                     parser->available_usages = 1;
24612ccb71bSMatthias Ringwald                     parser->usage_minimum = usage_value;
24712ccb71bSMatthias Ringwald                     break;
24812ccb71bSMatthias Ringwald                 case UsageMinimum:
24912ccb71bSMatthias Ringwald                     parser->usage_minimum = usage_value;
250*1a05cde1SMatthias Ringwald                     have_usage_min = true;
25112ccb71bSMatthias Ringwald                     break;
25212ccb71bSMatthias Ringwald                 case UsageMaximum:
25312ccb71bSMatthias Ringwald                     parser->usage_maximum = usage_value;
254*1a05cde1SMatthias Ringwald                     have_usage_max = true;
25512ccb71bSMatthias Ringwald                     break;
25612ccb71bSMatthias Ringwald                 default:
25712ccb71bSMatthias Ringwald                     break;
25812ccb71bSMatthias Ringwald             }
259*1a05cde1SMatthias Ringwald             if (have_usage_min && have_usage_max){
2604ea43905SMatthias Ringwald                 parser->available_usages = parser->usage_maximum - parser->usage_minimum + 1u;
261*1a05cde1SMatthias Ringwald                 parser->usage_range = true;
262dfb01e77SMatthias Ringwald                 if (parser->available_usages < parser->required_usages){
263dfb01e77SMatthias Ringwald                     log_debug("Usage Min - Usage Max [%04x..%04x] < Report Count %u", parser->usage_minimum, parser->usage_maximum, parser->required_usages);
264dfb01e77SMatthias Ringwald                 }
26512ccb71bSMatthias Ringwald             }
26612ccb71bSMatthias Ringwald         }
26712ccb71bSMatthias Ringwald         parser->usage_pos += usage_item.item_size;
26812ccb71bSMatthias Ringwald     }
26912ccb71bSMatthias Ringwald }
27012ccb71bSMatthias Ringwald 
27112ccb71bSMatthias Ringwald static void hid_process_item(btstack_hid_parser_t * parser, hid_descriptor_item_t * item){
27212ccb71bSMatthias Ringwald     hid_pretty_print_item(parser, item);
27312ccb71bSMatthias Ringwald     int valid_field = 0;
2747bbeb3adSMilanka Ringwald     switch ((TagType)item->item_type){
27512ccb71bSMatthias Ringwald         case Main:
2767bbeb3adSMilanka Ringwald             switch ((MainItemTag)item->item_tag){
27712ccb71bSMatthias Ringwald                 case Input:
278662cddc2SMilanka Ringwald                     valid_field = parser->report_type == HID_REPORT_TYPE_INPUT;
27912ccb71bSMatthias Ringwald                     break;
28012ccb71bSMatthias Ringwald                 case Output:
281662cddc2SMilanka Ringwald                     valid_field = parser->report_type == HID_REPORT_TYPE_OUTPUT;
28212ccb71bSMatthias Ringwald                     break;
28312ccb71bSMatthias Ringwald                 case Feature:
284662cddc2SMilanka Ringwald                     valid_field = parser->report_type == HID_REPORT_TYPE_FEATURE;
28512ccb71bSMatthias Ringwald                     break;
28612ccb71bSMatthias Ringwald                 default:
28712ccb71bSMatthias Ringwald                     break;
28812ccb71bSMatthias Ringwald             }
28912ccb71bSMatthias Ringwald             break;
29012ccb71bSMatthias Ringwald         case Global:
29112ccb71bSMatthias Ringwald             btstack_hid_handle_global_item(parser, item);
29212ccb71bSMatthias Ringwald             break;
29312ccb71bSMatthias Ringwald         case Local:
2947bbeb3adSMilanka Ringwald         case Reserved:
2957bbeb3adSMilanka Ringwald             break;
2967bbeb3adSMilanka Ringwald         default:
2977bbeb3adSMilanka Ringwald             btstack_assert(false);
29812ccb71bSMatthias Ringwald             break;
29912ccb71bSMatthias Ringwald     }
30012ccb71bSMatthias Ringwald     if (!valid_field) return;
30112ccb71bSMatthias Ringwald 
30212ccb71bSMatthias Ringwald     // verify record id
30312ccb71bSMatthias Ringwald     if (parser->global_report_id && !parser->active_record){
30412ccb71bSMatthias Ringwald         if (parser->report[0] != parser->global_report_id){
30512ccb71bSMatthias Ringwald             return;
30612ccb71bSMatthias Ringwald         }
3074ea43905SMatthias Ringwald         parser->report_pos_in_bit += 8u;
30812ccb71bSMatthias Ringwald     }
30912ccb71bSMatthias Ringwald     parser->active_record = 1;
31012ccb71bSMatthias Ringwald     // handle constant fields used for padding
31112ccb71bSMatthias Ringwald     if (item->item_value & 1){
31212ccb71bSMatthias Ringwald         int item_bits = parser->global_report_size * parser->global_report_count;
31312ccb71bSMatthias Ringwald #ifdef HID_PARSER_PRETTY_PRINT
31412ccb71bSMatthias Ringwald         log_info("- Skip %u constant bits", item_bits);
31512ccb71bSMatthias Ringwald #endif
31612ccb71bSMatthias Ringwald         parser->report_pos_in_bit += item_bits;
31712ccb71bSMatthias Ringwald         return;
31812ccb71bSMatthias Ringwald     }
31912ccb71bSMatthias Ringwald     // Empty Item
3204ea43905SMatthias Ringwald     if (parser->global_report_count == 0u) return;
32112ccb71bSMatthias Ringwald     // let's start
32212ccb71bSMatthias Ringwald     parser->required_usages = parser->global_report_count;
32312ccb71bSMatthias Ringwald }
32412ccb71bSMatthias Ringwald 
32512ccb71bSMatthias Ringwald static void hid_post_process_item(btstack_hid_parser_t * parser, hid_descriptor_item_t * item){
3267bbeb3adSMilanka Ringwald     if ((TagType)item->item_type == Main){
32712ccb71bSMatthias Ringwald         // reset usage
32812ccb71bSMatthias Ringwald         parser->usage_pos  = parser->descriptor_pos;
32912ccb71bSMatthias Ringwald         parser->usage_page = parser->global_usage_page;
33012ccb71bSMatthias Ringwald     }
33112ccb71bSMatthias Ringwald     parser->descriptor_pos += item->item_size;
33212ccb71bSMatthias Ringwald }
33312ccb71bSMatthias Ringwald 
33412ccb71bSMatthias Ringwald static void btstack_hid_parser_find_next_usage(btstack_hid_parser_t * parser){
33512ccb71bSMatthias Ringwald     while (parser->state == BTSTACK_HID_PARSER_SCAN_FOR_REPORT_ITEM){
33612ccb71bSMatthias Ringwald         if (parser->descriptor_pos >= parser->descriptor_len){
33712ccb71bSMatthias Ringwald             // end of descriptor
33812ccb71bSMatthias Ringwald             parser->state = BTSTACK_HID_PARSER_COMPLETE;
33912ccb71bSMatthias Ringwald             break;
34012ccb71bSMatthias Ringwald         }
34112ccb71bSMatthias Ringwald         btstack_hid_parse_descriptor_item(&parser->descriptor_item, &parser->descriptor[parser->descriptor_pos], parser->descriptor_len - parser->descriptor_pos);
34212ccb71bSMatthias Ringwald         hid_process_item(parser, &parser->descriptor_item);
34312ccb71bSMatthias Ringwald         if (parser->required_usages){
34412ccb71bSMatthias Ringwald             hid_find_next_usage(parser);
34512ccb71bSMatthias Ringwald             if (parser->available_usages) {
34612ccb71bSMatthias Ringwald                 parser->state = BTSTACK_HID_PARSER_USAGES_AVAILABLE;
34712ccb71bSMatthias Ringwald             } else {
348dfb01e77SMatthias Ringwald                 log_debug("no usages found");
34912ccb71bSMatthias Ringwald                 parser->state = BTSTACK_HID_PARSER_COMPLETE;
35012ccb71bSMatthias Ringwald             }
35112ccb71bSMatthias Ringwald         } else {
35212ccb71bSMatthias Ringwald             hid_post_process_item(parser, &parser->descriptor_item);
35312ccb71bSMatthias Ringwald         }
35412ccb71bSMatthias Ringwald     }
35512ccb71bSMatthias Ringwald }
35612ccb71bSMatthias Ringwald 
35712ccb71bSMatthias Ringwald // PUBLIC API
35812ccb71bSMatthias Ringwald 
359662cddc2SMilanka Ringwald 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){
36012ccb71bSMatthias Ringwald 
36112ccb71bSMatthias Ringwald     memset(parser, 0, sizeof(btstack_hid_parser_t));
36212ccb71bSMatthias Ringwald 
36312ccb71bSMatthias Ringwald     parser->descriptor     = hid_descriptor;
36412ccb71bSMatthias Ringwald     parser->descriptor_len = hid_descriptor_len;
36512ccb71bSMatthias Ringwald     parser->report_type    = hid_report_type;
36612ccb71bSMatthias Ringwald     parser->report         = hid_report;
36712ccb71bSMatthias Ringwald     parser->report_len     = hid_report_len;
36812ccb71bSMatthias Ringwald     parser->state          = BTSTACK_HID_PARSER_SCAN_FOR_REPORT_ITEM;
36912ccb71bSMatthias Ringwald 
37012ccb71bSMatthias Ringwald     btstack_hid_parser_find_next_usage(parser);
37112ccb71bSMatthias Ringwald }
37212ccb71bSMatthias Ringwald 
37312ccb71bSMatthias Ringwald int  btstack_hid_parser_has_more(btstack_hid_parser_t * parser){
37412ccb71bSMatthias Ringwald     return parser->state == BTSTACK_HID_PARSER_USAGES_AVAILABLE;
37512ccb71bSMatthias Ringwald }
37612ccb71bSMatthias Ringwald 
37712ccb71bSMatthias Ringwald void btstack_hid_parser_get_field(btstack_hid_parser_t * parser, uint16_t * usage_page, uint16_t * usage, int32_t * value){
37812ccb71bSMatthias Ringwald 
37912ccb71bSMatthias Ringwald     *usage_page = parser->usage_minimum >> 16;
38012ccb71bSMatthias Ringwald 
38112ccb71bSMatthias Ringwald     // read field (up to 32 bit unsigned, up to 31 bit signed - 32 bit signed behaviour is undefined) - check report len
3821979f09cSMatthias Ringwald     bool is_variable   = (parser->descriptor_item.item_value & 2) != 0;
3831979f09cSMatthias Ringwald     bool is_signed     = parser->global_logical_minimum < 0;
38412ccb71bSMatthias Ringwald     int pos_start     = btstack_min(  parser->report_pos_in_bit >> 3, parser->report_len);
3854ea43905SMatthias Ringwald     int pos_end       = btstack_min( (parser->report_pos_in_bit + parser->global_report_size - 1u) >> 3u, parser->report_len);
38612ccb71bSMatthias Ringwald     int bytes_to_read = pos_end - pos_start + 1;
38712ccb71bSMatthias Ringwald     int i;
38812ccb71bSMatthias Ringwald     uint32_t multi_byte_value = 0;
38912ccb71bSMatthias Ringwald     for (i=0;i < bytes_to_read;i++){
39012ccb71bSMatthias Ringwald         multi_byte_value |= parser->report[pos_start+i] << (i*8);
39112ccb71bSMatthias Ringwald     }
3924ea43905SMatthias Ringwald     uint32_t unsigned_value = (multi_byte_value >> (parser->report_pos_in_bit & 0x07u)) & ((1u<<parser->global_report_size)-1u);
39312ccb71bSMatthias Ringwald     // log_debug("bit pos %2u, report size %u, start %u, end %u, len %u;; unsigned value %08x", parser->report_pos_in_bit, parser->global_report_size, pos_start, pos_end, parser->report_len, unsigned_value);
39412ccb71bSMatthias Ringwald     if (is_variable){
3954ea43905SMatthias Ringwald         *usage      = parser->usage_minimum & 0xffffu;
3964ea43905SMatthias Ringwald         if (is_signed && (unsigned_value & (1u<<(parser->global_report_size-1u)))){
3974ea43905SMatthias Ringwald             *value = unsigned_value - (1u<<parser->global_report_size);
39812ccb71bSMatthias Ringwald         } else {
39912ccb71bSMatthias Ringwald             *value = unsigned_value;
40012ccb71bSMatthias Ringwald         }
40112ccb71bSMatthias Ringwald     } else {
40212ccb71bSMatthias Ringwald         *usage  = unsigned_value;
40312ccb71bSMatthias Ringwald         *value  = 1;
40412ccb71bSMatthias Ringwald     }
40512ccb71bSMatthias Ringwald     parser->required_usages--;
40612ccb71bSMatthias Ringwald     parser->report_pos_in_bit += parser->global_report_size;
40712ccb71bSMatthias Ringwald 
40812ccb71bSMatthias Ringwald     // next usage
40912ccb71bSMatthias Ringwald     if (is_variable){
41012ccb71bSMatthias Ringwald         parser->usage_minimum++;
41112ccb71bSMatthias Ringwald         parser->available_usages--;
412*1a05cde1SMatthias Ringwald         if (parser->usage_range && (parser->usage_minimum > parser->usage_maximum)){
413dfb01e77SMatthias Ringwald             // usage min - max range smaller than report count, ignore remaining bit in report
414dfb01e77SMatthias Ringwald             log_debug("Ignoring %u items without Usage", parser->required_usages);
415dfb01e77SMatthias Ringwald             parser->report_pos_in_bit += parser->global_report_size * parser->required_usages;
416dfb01e77SMatthias Ringwald             parser->required_usages = 0;
417dfb01e77SMatthias Ringwald         }
41812ccb71bSMatthias Ringwald     } else {
4194ea43905SMatthias Ringwald         if (parser->required_usages == 0u){
42012ccb71bSMatthias Ringwald             parser->available_usages = 0;
42112ccb71bSMatthias Ringwald         }
42212ccb71bSMatthias Ringwald     }
42312ccb71bSMatthias Ringwald     if (parser->available_usages) {
42412ccb71bSMatthias Ringwald         return;
42512ccb71bSMatthias Ringwald     }
4264ea43905SMatthias Ringwald     if (parser->required_usages == 0u){
42712ccb71bSMatthias Ringwald         hid_post_process_item(parser, &parser->descriptor_item);
42812ccb71bSMatthias Ringwald         parser->state = BTSTACK_HID_PARSER_SCAN_FOR_REPORT_ITEM;
42912ccb71bSMatthias Ringwald         btstack_hid_parser_find_next_usage(parser);
43012ccb71bSMatthias Ringwald     } else {
43112ccb71bSMatthias Ringwald         hid_find_next_usage(parser);
4324ea43905SMatthias Ringwald         if (parser->available_usages == 0u) {
43312ccb71bSMatthias Ringwald             parser->state = BTSTACK_HID_PARSER_COMPLETE;
43412ccb71bSMatthias Ringwald         }
43512ccb71bSMatthias Ringwald     }
43612ccb71bSMatthias Ringwald }
437fada7179SMilanka Ringwald 
438662cddc2SMilanka Ringwald 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){
439fada7179SMilanka Ringwald     int total_report_size = 0;
440fada7179SMilanka Ringwald     int report_size = 0;
441fada7179SMilanka Ringwald     int report_count = 0;
442fada7179SMilanka Ringwald     int current_report_id = 0;
443fada7179SMilanka Ringwald 
444fada7179SMilanka Ringwald     while (hid_descriptor_len){
445fada7179SMilanka Ringwald         int valid_report_type = 0;
446fada7179SMilanka Ringwald         hid_descriptor_item_t item;
447fada7179SMilanka Ringwald         btstack_hid_parse_descriptor_item(&item, hid_descriptor, hid_descriptor_len);
448fada7179SMilanka Ringwald         switch (item.item_type){
449fada7179SMilanka Ringwald             case Global:
450fada7179SMilanka Ringwald                 switch ((GlobalItemTag)item.item_tag){
451fada7179SMilanka Ringwald                     case ReportID:
452fada7179SMilanka Ringwald                         current_report_id = item.item_value;
453fada7179SMilanka Ringwald                         break;
454fada7179SMilanka Ringwald                     case ReportCount:
455fada7179SMilanka Ringwald                         report_count = item.item_value;
456fada7179SMilanka Ringwald                         break;
457fada7179SMilanka Ringwald                     case ReportSize:
458fada7179SMilanka Ringwald                         report_size = item.item_value;
459fada7179SMilanka Ringwald                         break;
460fada7179SMilanka Ringwald                     default:
461fada7179SMilanka Ringwald                         break;
462fada7179SMilanka Ringwald                 }
463fada7179SMilanka Ringwald                 break;
464fada7179SMilanka Ringwald             case Main:
465fada7179SMilanka Ringwald                 if (current_report_id != report_id) break;
466fada7179SMilanka Ringwald                 switch ((MainItemTag)item.item_tag){
467fada7179SMilanka Ringwald                     case Input:
468662cddc2SMilanka Ringwald                         if (report_type != HID_REPORT_TYPE_INPUT) break;
469fada7179SMilanka Ringwald                         valid_report_type = 1;
470fada7179SMilanka Ringwald                         break;
471fada7179SMilanka Ringwald                     case Output:
472662cddc2SMilanka Ringwald                         if (report_type != HID_REPORT_TYPE_OUTPUT) break;
473fada7179SMilanka Ringwald                         valid_report_type = 1;
474fada7179SMilanka Ringwald                         break;
475fada7179SMilanka Ringwald                     case Feature:
476662cddc2SMilanka Ringwald                         if (report_type != HID_REPORT_TYPE_FEATURE) break;
477fada7179SMilanka Ringwald                         valid_report_type = 1;
478fada7179SMilanka Ringwald                         break;
479fada7179SMilanka Ringwald                     default:
480fada7179SMilanka Ringwald                         break;
481fada7179SMilanka Ringwald                 }
482fada7179SMilanka Ringwald                 if (!valid_report_type) break;
483fada7179SMilanka Ringwald                 total_report_size += report_count * report_size;
484fada7179SMilanka Ringwald                 break;
485fada7179SMilanka Ringwald             default:
486fada7179SMilanka Ringwald                 break;
487fada7179SMilanka Ringwald         }
48815cf8612Sx0rloser 		if (total_report_size > 0 && current_report_id != report_id) break;
489fada7179SMilanka Ringwald         hid_descriptor_len -= item.item_size;
490fada7179SMilanka Ringwald         hid_descriptor += item.item_size;
491fada7179SMilanka Ringwald     }
492fada7179SMilanka Ringwald     return (total_report_size + 7)/8;
493fada7179SMilanka Ringwald }
494dbcaefc7SMilanka Ringwald 
495dbcaefc7SMilanka Ringwald hid_report_id_status_t btstack_hid_id_valid(int report_id, uint16_t hid_descriptor_len, const uint8_t * hid_descriptor){
496dbcaefc7SMilanka Ringwald     int current_report_id = 0;
497dbcaefc7SMilanka Ringwald     while (hid_descriptor_len){
498dbcaefc7SMilanka Ringwald         hid_descriptor_item_t item;
499dbcaefc7SMilanka Ringwald         btstack_hid_parse_descriptor_item(&item, hid_descriptor, hid_descriptor_len);
500dbcaefc7SMilanka Ringwald         switch (item.item_type){
501dbcaefc7SMilanka Ringwald             case Global:
502dbcaefc7SMilanka Ringwald                 switch ((GlobalItemTag)item.item_tag){
503dbcaefc7SMilanka Ringwald                     case ReportID:
504dbcaefc7SMilanka Ringwald                         current_report_id = item.item_value;
505dbcaefc7SMilanka Ringwald                         if (current_report_id != report_id) break;
506dbcaefc7SMilanka Ringwald                         return HID_REPORT_ID_VALID;
507dbcaefc7SMilanka Ringwald                     default:
508dbcaefc7SMilanka Ringwald                         break;
509dbcaefc7SMilanka Ringwald                 }
510dbcaefc7SMilanka Ringwald                 break;
511dbcaefc7SMilanka Ringwald             default:
512dbcaefc7SMilanka Ringwald                 break;
513dbcaefc7SMilanka Ringwald         }
514dbcaefc7SMilanka Ringwald         hid_descriptor_len -= item.item_size;
515dbcaefc7SMilanka Ringwald         hid_descriptor += item.item_size;
516dbcaefc7SMilanka Ringwald     }
517dbcaefc7SMilanka Ringwald     if (current_report_id != 0) return HID_REPORT_ID_INVALID;
518dbcaefc7SMilanka Ringwald     return HID_REPORT_ID_UNDECLARED;
519dbcaefc7SMilanka Ringwald }
520dbcaefc7SMilanka Ringwald 
521dbcaefc7SMilanka Ringwald int btstack_hid_report_id_declared(uint16_t hid_descriptor_len, const uint8_t * hid_descriptor){
522dbcaefc7SMilanka Ringwald     while (hid_descriptor_len){
523dbcaefc7SMilanka Ringwald         hid_descriptor_item_t item;
524dbcaefc7SMilanka Ringwald         btstack_hid_parse_descriptor_item(&item, hid_descriptor, hid_descriptor_len);
525dbcaefc7SMilanka Ringwald         switch (item.item_type){
526dbcaefc7SMilanka Ringwald             case Global:
527dbcaefc7SMilanka Ringwald                 switch ((GlobalItemTag)item.item_tag){
528dbcaefc7SMilanka Ringwald                     case ReportID:
529dbcaefc7SMilanka Ringwald                         return 1;
530dbcaefc7SMilanka Ringwald                     default:
531dbcaefc7SMilanka Ringwald                         break;
532dbcaefc7SMilanka Ringwald                 }
533dbcaefc7SMilanka Ringwald                 break;
534dbcaefc7SMilanka Ringwald             default:
535dbcaefc7SMilanka Ringwald                 break;
536dbcaefc7SMilanka Ringwald         }
537dbcaefc7SMilanka Ringwald         hid_descriptor_len -= item.item_size;
538dbcaefc7SMilanka Ringwald         hid_descriptor += item.item_size;
539dbcaefc7SMilanka Ringwald     }
540dbcaefc7SMilanka Ringwald     return 0;
541dbcaefc7SMilanka Ringwald }
542