added dcd_sof_enable(), tud_sof_isr_set()

make number of interface configurable (default to 8)
CFG_TUD_INTERFACE_MAX

src/device/dcd.h

@@ -77,6 +77,11 @@ typedef struct TU_ATTR_ALIGNED(4)
       tusb_speed_t speed;
     } bus_reset;
 
+    // SOF
+    struct {
+      uint32_t frame_count;
+    }sof;
+
     // SETUP_RECEIVED
     tusb_control_request_t setup_received;
 
@@ -132,6 +137,9 @@ void dcd_connect(uint8_t rhport) TU_ATTR_WEAK;
 // Disconnect by disabling internal pull-up resistor on D+/D-
 void dcd_disconnect(uint8_t rhport) TU_ATTR_WEAK;
 
+// Enable/Disable Start-of-frame interrupt. Default is disabled
+void dcd_sof_enable(uint8_t rhport, bool en);
+
 //--------------------------------------------------------------------+
 // Endpoint API
 //--------------------------------------------------------------------+
@@ -185,6 +193,13 @@ extern void dcd_event_setup_received(uint8_t rhport, uint8_t const * setup, bool
 // helper to send transfer complete event
 extern void dcd_event_xfer_complete (uint8_t rhport, uint8_t ep_addr, uint32_t xferred_bytes, uint8_t result, bool in_isr);
 
+static inline void dcd_event_sof(uint8_t rhport, uint32_t frame_count, bool in_isr)
+{
+  dcd_event_t event = { .rhport = rhport, .event_id = DCD_EVENT_SOF };
+  event.sof.frame_count = frame_count;
+  dcd_event_handler(&event, in_isr);
+}
+
 #ifdef __cplusplus
  }
 #endif