improve hid parser

examples/host/cdc_msc_hid/src/hid_app.c

@@ -37,14 +37,16 @@
 
 static uint8_t const keycode2ascii[128][2] =  { HID_KEYCODE_TO_ASCII };
 
+// Each HID instance can has multiple reports
 static uint8_t _report_count[CFG_TUH_HID];
-static tuh_hid_report_info_t _report_info[CFG_TUH_HID][MAX_REPORT];
+static tuh_hid_report_info_t _report_info_arr[CFG_TUH_HID][MAX_REPORT];
 
 static void process_kbd_report(hid_keyboard_report_t const *report);
 static void process_mouse_report(hid_mouse_report_t const * report);
 
 void hid_app_task(void)
 {
+  // nothing to do
 }
 
 //--------------------------------------------------------------------+
@@ -55,21 +57,13 @@ void tuh_hid_mounted_cb(uint8_t dev_addr, uint8_t instance, uint8_t const* desc_
 {
   printf("HID device address = %d, instance = %d is mounted\r\n", dev_addr, instance);
 
-  // Parse report descriptor with built-in parser
-  _report_count[instance] = tuh_hid_parse_report_descriptor(_report_info[instance], MAX_REPORT, desc_report, desc_len);
-
-  if (_report_count[instance])
-  {
-    printf("Composite with %u reports", _report_count[instance]);
-  }else
-  {
-    printf("Single report");
-  }
-
   // Interface protocol
   const char* protocol_str[] = { "None", "Keyboard", "Mouse" }; // hid_protocol_type_t
   uint8_t const interface_protocol = tuh_hid_interface_protocol(dev_addr, instance);
-  printf(", Interface protocol = %s, ", protocol_str[interface_protocol]);
+
+  // Parse report descriptor with built-in parser
+  _report_count[instance] = tuh_hid_parse_report_descriptor(_report_info_arr[instance], MAX_REPORT, desc_report, desc_len);
+  printf("HID has %u reports and interface protocol = %s\r\n", _report_count[instance], protocol_str[interface_protocol]);
 }
 
 void tuh_hid_unmounted_cb(uint8_t dev_addr, uint8_t instance)
@@ -82,20 +76,36 @@ void tuh_hid_get_report_cb(uint8_t dev_addr, uint8_t instance, uint8_t const* re
   (void) dev_addr;
 
   uint8_t const rpt_count = _report_count[instance];
-  tuh_hid_report_info_t* rpt_info;
+  tuh_hid_report_info_t* rpt_info_arr = _report_info_arr[instance];
+  tuh_hid_report_info_t* rpt_info = NULL;
 
-  if (rpt_count)
+  if ( rpt_count == 1 && rpt_info_arr[0].report_id == 0)
+  {
+    // Simple report without report ID as 1st byte
+    rpt_info = &rpt_info_arr[0];
+  }else
   {
     // Composite report, 1st byte is report ID, data starts from 2nd byte
-    // Note: report index = report ID - 1
-    uint8_t idx = report[0] - 1;
-    rpt_info = &_report_info[instance][idx];
+    uint8_t const rpt_id = report[0];
+
+    // Find report id in the arrray
+    for(uint8_t i=0; i<rpt_count; i++)
+    {
+      if (rpt_id == rpt_info_arr[i].report_id )
+      {
+        rpt_info = &rpt_info_arr[i];
+        break;
+      }
+    }
 
     report++;
     len--;
-  }else
+  }
+
+  if (!rpt_info)
   {
-    rpt_info = &_report_info[instance][0];
+    printf("Couldn't find the report info for this report !\r\n");
+    return;
   }
 
   if ( rpt_info->usage_page == HID_USAGE_PAGE_DESKTOP )

src/class/hid/hid_host.c

@@ -337,7 +337,7 @@ bool config_get_report_desc_complete(uint8_t dev_addr, tusb_control_request_t co
 // Report Descriptor Parser
 //--------------------------------------------------------------------+
 
-uint8_t tuh_hid_parse_report_descriptor(tuh_hid_report_info_t* report_info, uint8_t arr_count, uint8_t const* desc_report, uint16_t desc_len)
+uint8_t tuh_hid_parse_report_descriptor(tuh_hid_report_info_t* report_info_arr, uint8_t arr_count, uint8_t const* desc_report, uint16_t desc_len)
 {
   // Report Item 6.2.2.2 USB HID 1.11
   union TU_ATTR_PACKED
@@ -351,18 +351,16 @@ uint8_t tuh_hid_parse_report_descriptor(tuh_hid_report_info_t* report_info, uint
     };
   } header;
 
-  uint8_t report_num = 0;
-  tuh_hid_report_info_t* info = report_info;
+  tu_memclr(report_info_arr, arr_count*sizeof(tuh_hid_report_info_t));
 
-  tu_memclr(report_info, arr_count*sizeof(tuh_hid_report_info_t));
+  uint8_t report_num = 0;
+  tuh_hid_report_info_t* info = report_info_arr;
 
   // current parsed report count & size from descriptor
 //  uint8_t ri_report_count = 0;
 //  uint8_t ri_report_size = 0;
 
   uint8_t ri_collection_depth = 0;
-  uint16_t ri_usage_page = 0;
-  uint8_t ri_usage = 0;
 
   while(desc_len && report_num < arr_count)
   {
@@ -394,6 +392,11 @@ uint8_t tuh_hid_parse_report_descriptor(tuh_hid_report_info_t* report_info, uint
 
           case RI_MAIN_COLLECTION_END:
             ri_collection_depth--;
+            if (ri_collection_depth == 0)
+            {
+              info++;
+              report_num++;
+            }
           break;
 
           default: break;
@@ -404,11 +407,8 @@ uint8_t tuh_hid_parse_report_descriptor(tuh_hid_report_info_t* report_info, uint
         switch(tag)
         {
           case RI_GLOBAL_USAGE_PAGE:
-            // only take in account the "usage page" before starting COLLECTION
-            if ( ri_collection_depth == 0)
-            {
-              memcpy(&ri_usage_page, desc_report, size);
-            }
+            // only take in account the "usage page" before REPORT ID
+            if ( ri_collection_depth == 0 ) memcpy(&info->usage_page, desc_report, size);
           break;
 
           case RI_GLOBAL_LOGICAL_MIN   : break;
@@ -417,23 +417,7 @@ uint8_t tuh_hid_parse_report_descriptor(tuh_hid_report_info_t* report_info, uint
           case RI_GLOBAL_PHYSICAL_MAX  : break;
 
           case RI_GLOBAL_REPORT_ID:
-            report_num++;
-            if (data8 <= arr_count)
-            {
-              uint8_t const idx = data8 - 1;
-              if ( info != &report_info[idx] )
-              {
-                // copy info so far to its correct report ID, and update info pointer
-                report_info[idx] = *info;
-                info = &report_info[idx];
-              }
-
-              info->usage_page = ri_usage_page;
-              info->usage = ri_usage;
-            }else
-            {
-              TU_LOG2("HID Skip a report with ID (%u) larger than array count (%u)\r\n", data8, arr_count);
-            }
+            info->report_id = data8;
           break;
 
           case RI_GLOBAL_REPORT_SIZE:
@@ -457,8 +441,8 @@ uint8_t tuh_hid_parse_report_descriptor(tuh_hid_report_info_t* report_info, uint
         switch(tag)
         {
           case RI_LOCAL_USAGE:
-            // only take in account the "usage" before starting COLLECTION
-            if ( ri_collection_depth == 0) ri_usage = data8;
+            // only take in account the "usage" before starting REPORT ID
+            if ( ri_collection_depth == 0 ) info->usage = data8;
           break;
 
           case RI_LOCAL_USAGE_MIN        : break;
@@ -482,16 +466,10 @@ uint8_t tuh_hid_parse_report_descriptor(tuh_hid_report_info_t* report_info, uint
     desc_len    -= size;
   }
 
-  if ( report_num == 0 )
-  {
-    report_info[0].usage_page = ri_usage_page;
-    report_info[0].usage = ri_usage;
-  }
-
-  for ( uint8_t i = 0; (i < report_num) || (!i && !report_num); i++ )
+  for ( uint8_t i = 0; i < report_num; i++ )
   {
-    info = report_info+i;
-    TU_LOG2("%u: usage_page = %u, usage = %u\r\n", i, info->usage_page, info->usage);
+    info = report_info_arr+i;
+    TU_LOG2("%u: id = %u, usage_page = %u, usage = %u\r\n", i, info->report_id, info->usage_page, info->usage);
   }
 
   return report_num;

src/class/hid/hid_host.h

@@ -53,8 +53,9 @@
 
 typedef struct
 {
+  uint8_t  report_id;
+  uint8_t  usage;
   uint16_t usage_page;
-  uint8_t usage;
 
   // TODO still use the endpoint size for now
 //  uint8_t in_len;      // length of IN report
@@ -83,9 +84,8 @@ bool tuh_hid_get_protocol(uint8_t dev_addr, uint8_t instance);
 bool tuh_hid_set_protocol(uint8_t dev_addr, uint8_t instance, uint8_t protocol);
 
 // Parse report descriptor into array of report_info struct and return number of reports.
-// If return 0, this is a ingle report, otherwise it is composite report with 1st byte as ID.
 // For complicated report, application should write its own parser.
-uint8_t tuh_hid_parse_report_descriptor(tuh_hid_report_info_t* report_info, uint8_t arr_count, uint8_t const* desc_report, uint16_t desc_len) TU_ATTR_UNUSED;
+uint8_t tuh_hid_parse_report_descriptor(tuh_hid_report_info_t* reports_info_arr, uint8_t arr_count, uint8_t const* desc_report, uint16_t desc_len) TU_ATTR_UNUSED;
 
 // Check if the interface is ready to use
 //bool tuh_n_hid_n_ready(uint8_t dev_addr, uint8_t instance);