diff --git a/src/class/cdc/cdc_device.c b/src/class/cdc/cdc_device.c
index cac811c4..a926081c 100644
--- a/src/class/cdc/cdc_device.c
+++ b/src/class/cdc/cdc_device.c
@@ -483,4 +483,18 @@ bool cdcd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_
   return true;
 }
 
+// Get the Receive FIFO (for DMA transfer)
+tu_fifo_t* tud_cdc_n_get_rx_ff (uint8_t itf)
+{
+  TU_ASSERT(itf < CFG_TUD_CDC);
+  return &_cdcd_itf[itf].rx_ff;
+}
+
+// Get the transmit FIFO (for DMA transfer)
+tu_fifo_t* tud_cdc_n_get_tx_ff (uint8_t itf)
+{
+  TU_ASSERT(itf < CFG_TUD_CDC);
+  return &_cdcd_itf[itf].tx_ff;
+}
+
 #endif
diff --git a/src/class/cdc/cdc_device.h b/src/class/cdc/cdc_device.h
index 7ff757ad..f8a2216c 100644
--- a/src/class/cdc/cdc_device.h
+++ b/src/class/cdc/cdc_device.h
@@ -104,6 +104,12 @@ uint32_t tud_cdc_n_write_available (uint8_t itf);
 // Clear the transmit FIFO
 bool tud_cdc_n_write_clear (uint8_t itf);
 
+// Get the Receive FIFO (for DMA transfer)
+tu_fifo_t* tud_cdc_n_get_rx_ff (uint8_t itf);
+
+// Get the transmit FIFO (for DMA transfer)
+tu_fifo_t* tud_cdc_n_get_tx_ff (uint8_t itf);
+
 //--------------------------------------------------------------------+
 // Application API (Single Port)
 //--------------------------------------------------------------------+
@@ -241,6 +247,18 @@ static inline bool tud_cdc_write_clear(void)
   return tud_cdc_n_write_clear(0);
 }
 
+// Get the Receive FIFO
+static inline tu_fifo_t* tud_cdc_get_rx_ff (void)
+{
+  return tud_cdc_n_get_rx_ff(0);
+}
+
+// Get the transmit FIFO
+static inline tu_fifo_t* tud_cdc_get_tx_ff (void)
+{
+  return tud_cdc_n_get_tx_ff(0);
+}
+
 /** @} */
 /** @} */
 
diff --git a/src/device/usbd.h b/src/device/usbd.h
index 3857295d..0a0f0bf0 100644
--- a/src/device/usbd.h
+++ b/src/device/usbd.h
@@ -236,7 +236,7 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
 // Interface number, string index, protocol, report descriptor len, EP In address, size & polling interval
 #define TUD_HID_DESCRIPTOR(_itfnum, _stridx, _boot_protocol, _report_desc_len, _epin, _epsize, _ep_interval) \
   /* Interface */\
-  9, TUSB_DESC_INTERFACE, _itfnum, 0, 1, TUSB_CLASS_HID, (uint8_t)((_boot_protocol) ? HID_SUBCLASS_BOOT : 0), _boot_protocol, _stridx,\
+  9, TUSB_DESC_INTERFACE, _itfnum, 0, 1, TUSB_CLASS_HID, (uint8_t)((_boot_protocol) ? (uint8_t)HID_SUBCLASS_BOOT : 0), _boot_protocol, _stridx,\
   /* HID descriptor */\
   9, HID_DESC_TYPE_HID, U16_TO_U8S_LE(0x0111), 0, 1, HID_DESC_TYPE_REPORT, U16_TO_U8S_LE(_report_desc_len),\
   /* Endpoint In */\
@@ -249,7 +249,7 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
 // Interface number, string index, protocol, report descriptor len, EP OUT & IN address, size & polling interval
 #define TUD_HID_INOUT_DESCRIPTOR(_itfnum, _stridx, _boot_protocol, _report_desc_len, _epout, _epin, _epsize, _ep_interval) \
   /* Interface */\
-  9, TUSB_DESC_INTERFACE, _itfnum, 0, 2, TUSB_CLASS_HID, (uint8_t)((_boot_protocol) ? HID_SUBCLASS_BOOT : 0), _boot_protocol, _stridx,\
+  9, TUSB_DESC_INTERFACE, _itfnum, 0, 2, TUSB_CLASS_HID, (uint8_t)((_boot_protocol) ? (uint8_t)HID_SUBCLASS_BOOT : 0), _boot_protocol, _stridx,\
   /* HID descriptor */\
   9, HID_DESC_TYPE_HID, U16_TO_U8S_LE(0x0111), 0, 1, HID_DESC_TYPE_REPORT, U16_TO_U8S_LE(_report_desc_len),\
   /* Endpoint Out */\