tud_hid_report_complete_cb() API

update hid composite to make use of tud_hid_report_complete_cb() for
sending reports when possible.

3 files changed, 106 insertions, 84 deletions

diff --git a/examples/device/hid_composite/src/main.c b/examples/device/hid_composite/src/main.c
index 45b8ba674..9fb2de88d 100644
--- a/examples/device/hid_composite/src/main.c
+++ b/examples/device/hid_composite/src/main.c
@@ -104,114 +104,135 @@ void tud_resume_cb(void)
 // USB HID
 //--------------------------------------------------------------------+
 
-void hid_task(void)
+static void send_hid_report(uint8_t report_id, uint32_t btn)
 {
-  // Poll every 10ms
-  const uint32_t interval_ms = 10;
-  static uint32_t start_ms = 0;
+  // skip if hid is not ready yet
+  if ( !tud_hid_ready() ) return;
 
-  if ( board_millis() - start_ms < interval_ms) return; // not enough time
-  start_ms += interval_ms;
+  switch(report_id)
+  {
+    case REPORT_ID_KEYBOARD:
+    {
+      // use to avoid send multiple consecutive zero report for keyboard
+      static bool has_keyboard_key = false;
 
-  uint32_t const btn = board_button_read();
+      if ( btn )
+      {
+        uint8_t keycode[6] = { 0 };
+        keycode[0] = HID_KEY_A;
 
-  // Remote wakeup
-  if ( tud_suspended() && btn )
-  {
-    // Wake up host if we are in suspend mode
-    // and REMOTE_WAKEUP feature is enabled by host
-    tud_remote_wakeup();
-  }
+        tud_hid_keyboard_report(REPORT_ID_KEYBOARD, 0, keycode);
+        has_keyboard_key = true;
+      }else
+      {
+        // send empty key report if previously has key pressed
+        if (has_keyboard_key) tud_hid_keyboard_report(REPORT_ID_KEYBOARD, 0, NULL);
+        has_keyboard_key = false;
+      }
+    }
+    break;
 
-  /*------------- Mouse -------------*/
-  if ( tud_hid_ready() )
-  {
-    if ( btn )
+    case REPORT_ID_MOUSE:
     {
       int8_t const delta = 5;
 
-      // no button, right + down, no scroll pan
+      // no button, right + down, no scroll, no pan
       tud_hid_mouse_report(REPORT_ID_MOUSE, 0x00, delta, delta, 0, 0);
-
-      // delay a bit before sending keyboard report
-      board_delay(10);
     }
-  }
-
-  /*------------- Keyboard -------------*/
-  if ( tud_hid_ready() )
-  {
-    // use to avoid send multiple consecutive zero report for keyboard
-    static bool has_key = false;
+    break;
 
-    if ( btn )
+    case REPORT_ID_CONSUMER_CONTROL:
     {
-      uint8_t keycode[6] = { 0 };
-      keycode[0] = HID_KEY_A;
-
-      tud_hid_keyboard_report(REPORT_ID_KEYBOARD, 0, keycode);
+      // use to avoid send multiple consecutive zero report
+      static bool has_consumer_key = false;
 
-      has_key = true;
-    }else
-    {
-      // send empty key report if previously has key pressed
-      if (has_key) tud_hid_keyboard_report(REPORT_ID_KEYBOARD, 0, NULL);
-      has_key = false;
+      if ( btn )
+      {
+        // volume down
+        uint16_t volume_down = HID_USAGE_CONSUMER_VOLUME_DECREMENT;
+        tud_hid_report(REPORT_ID_CONSUMER_CONTROL, &volume_down, 2);
+        has_consumer_key = true;
+      }else
+      {
+        // send empty key report (release key) if previously has key pressed
+        uint16_t empty_key = 0;
+        if (has_consumer_key) tud_hid_report(REPORT_ID_CONSUMER_CONTROL, &empty_key, 2);
+        has_consumer_key = false;
+      }
     }
+    break;
 
-    // delay a bit before sending consumer report
-    board_delay(10);
-  }
+    case REPORT_ID_GAMEPAD:
+    {
+      // use to avoid send multiple consecutive zero report for keyboard
+      static bool has_gamepad_key = false;
 
-  /*------------- Consume Control -------------*/
-  if ( tud_hid_ready() )
-  {
-    // use to avoid send multiple consecutive zero report
-    static bool has_consumer_key = false;
+      hid_gamepad_report_t report =
+      {
+        .x   = 0, .y = 0, .z = 0, .rz = 0, .rx = 0, .ry = 0,
+        .hat = 0, .buttons = 0
+      };
 
-    if ( btn )
-    {
-      // volume down
-      uint16_t volume_down = HID_USAGE_CONSUMER_VOLUME_DECREMENT;
-      tud_hid_report(REPORT_ID_CONSUMER_CONTROL, &volume_down, 2);
+      if ( btn )
+      {
+        report.hat = GAMEPAD_HAT_UP;
+        report.buttons = GAMEPAD_BUTTON_A;
+        tud_hid_report(REPORT_ID_GAMEPAD, &report, sizeof(report));
 
-      has_consumer_key = true;
-    }else
-    {
-      // send empty key report (release key) if previously has key pressed
-      uint16_t empty_key = 0;
-      if (has_consumer_key) tud_hid_report(REPORT_ID_CONSUMER_CONTROL, &empty_key, 2);
-      has_consumer_key = false;
+        has_gamepad_key = true;
+      }else
+      {
+        report.hat = GAMEPAD_HAT_CENTERED;
+        report.buttons = 0;
+        if (has_gamepad_key) tud_hid_report(REPORT_ID_GAMEPAD, &report, sizeof(report));
+        has_gamepad_key = false;
+      }
     }
+    break;
 
-    // delay a bit before sending next report
-    board_delay(10);
+    default: break;
   }
+}
+
+// Every 10ms, we will sent 1 report for each HID profile (keyboard, mouse etc ..)
+// tud_hid_report_complete_cb() is used to send the next report after previous one is complete
+void hid_task(void)
+{
+  // Poll every 10ms
+  const uint32_t interval_ms = 10;
+  static uint32_t start_ms = 0;
+
+  if ( board_millis() - start_ms < interval_ms) return; // not enough time
+  start_ms += interval_ms;
 
-  /*------------- Gamepad -------------*/
-  if ( tud_hid_ready() )
+  uint32_t const btn = board_button_read();
+
+  // Remote wakeup
+  if ( tud_suspended() && btn )
   {
-    // use to avoid send multiple consecutive zero report for keyboard
-    static bool has_gamepad_key = false;
+    // Wake up host if we are in suspend mode
+    // and REMOTE_WAKEUP feature is enabled by host
+    tud_remote_wakeup();
+  }else
+  {
+    // Send the 1st of report chain, the rest will be sent by tud_hid_report_complete_cb()
+    send_hid_report(REPORT_ID_KEYBOARD, btn);
+  }
+}
 
-    hid_gamepad_report_t report =
-    {
-      .x   = 0, .y = 0, .z = 0, .rz = 0, .rx = 0, .ry = 0,
-      .hat = 0, .buttons = 0
-    };
+// Invoked when sent REPORT successfully to host
+// Application can use this to send the next report
+// Note: For composite reports, report[0] is report ID
+void tud_hid_report_complete_cb(uint8_t itf, uint8_t const* report, uint8_t len)
+{
+  (void) itf;
+  (void) len;
 
-    if ( btn )
-    {
-      report.hat = GAMEPAD_HAT_UP;
-      tud_hid_report(REPORT_ID_GAMEPAD, &report, sizeof(report));
+  uint8_t next_report_id = report[0] + 1;
 
-      has_gamepad_key = true;
-    }else
-    {
-      report.hat = GAMEPAD_HAT_CENTERED;
-      if (has_gamepad_key) tud_hid_report(REPORT_ID_GAMEPAD, &report, sizeof(report));
-      has_gamepad_key = false;
-    }
+  if (next_report_id < REPORT_ID_COUNT)
+  {
+    send_hid_report(next_report_id, board_button_read());
   }
 }
 
diff --git a/examples/device/hid_composite/src/usb_descriptors.c b/examples/device/hid_composite/src/usb_descriptors.c
index fbe0e2550..e5f1ea703 100644
--- a/examples/device/hid_composite/src/usb_descriptors.c
+++ b/examples/device/hid_composite/src/usb_descriptors.c
@@ -107,7 +107,7 @@ uint8_t const desc_configuration[] =
   TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP, 100),
 
   // Interface number, string index, protocol, report descriptor len, EP In address, size & polling interval
-  TUD_HID_DESCRIPTOR(ITF_NUM_HID, 0, HID_PROTOCOL_NONE, sizeof(desc_hid_report), EPNUM_HID, CFG_TUD_HID_EP_BUFSIZE, 10)
+  TUD_HID_DESCRIPTOR(ITF_NUM_HID, 0, HID_PROTOCOL_NONE, sizeof(desc_hid_report), EPNUM_HID, CFG_TUD_HID_EP_BUFSIZE, 2)
 };
 
 // Invoked when received GET CONFIGURATION DESCRIPTOR
diff --git a/examples/device/hid_composite/src/usb_descriptors.h b/examples/device/hid_composite/src/usb_descriptors.h
index 7894719fd..ca8925ad9 100644
--- a/examples/device/hid_composite/src/usb_descriptors.h
+++ b/examples/device/hid_composite/src/usb_descriptors.h
@@ -30,7 +30,8 @@ enum
   REPORT_ID_KEYBOARD = 1,
   REPORT_ID_MOUSE,
   REPORT_ID_CONSUMER_CONTROL,
-  REPORT_ID_GAMEPAD
+  REPORT_ID_GAMEPAD,
+  REPORT_ID_COUNT
 };
 
 #endif /* USB_DESCRIPTORS_H_ */