Merge pull request #2 from hathach/master

Pulling latest from source

6 files changed, 377 insertions, 223 deletions

diff --git a/src/class/cdc/cdc.h b/src/class/cdc/cdc.h
index f0488acbb..5df47f70b 100644
--- a/src/class/cdc/cdc.h
+++ b/src/class/cdc/cdc.h
@@ -1,4 +1,4 @@
-/* 
+/*
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
@@ -63,7 +63,7 @@ typedef enum
   CDC_COMM_SUBCLASS_TELEPHONE_CONTROL_MODEL           , ///< Telephone Control Model  [USBPSTN1.2]
   CDC_COMM_SUBCLASS_MULTICHANNEL_CONTROL_MODEL        , ///< Multi-Channel Control Model  [USBISDN1.2]
   CDC_COMM_SUBCLASS_CAPI_CONTROL_MODEL                , ///< CAPI Control Model  [USBISDN1.2]
-  CDC_COMM_SUBCLASS_ETHERNET_NETWORKING_CONTROL_MODEL , ///< Ethernet Networking Control Model  [USBECM1.2]
+  CDC_COMM_SUBCLASS_ETHERNET_CONTROL_MODEL            , ///< Ethernet Networking Control Model  [USBECM1.2]
   CDC_COMM_SUBCLASS_ATM_NETWORKING_CONTROL_MODEL      , ///< ATM Networking Control Model  [USBATM1.2]
   CDC_COMM_SUBCLASS_WIRELESS_HANDSET_CONTROL_MODEL    , ///< Wireless Handset Control Model  [USBWMC1.1]
   CDC_COMM_SUBCLASS_DEVICE_MANAGEMENT                 , ///< Device Management  [USBWMC1.1]
@@ -215,6 +215,10 @@ typedef enum
 // Class Specific Functional Descriptor (Communication Interface)
 //--------------------------------------------------------------------+
 
+// Start of all packed definitions for compiler without per-type packed
+TU_ATTR_PACKED_BEGIN
+TU_ATTR_BIT_FIELD_ORDER_BEGIN
+
 /// Header Functional Descriptor (Communication Interface)
 typedef struct TU_ATTR_PACKED
 {
@@ -235,7 +239,7 @@ typedef struct TU_ATTR_PACKED
 }cdc_desc_func_union_t;
 
 #define cdc_desc_func_union_n_t(no_slave)\
- struct TU_ATTR_PACKED { \
+ struct TU_ATTR_PACKED {                   \
   uint8_t bLength                         ;\
   uint8_t bDescriptorType                 ;\
   uint8_t bDescriptorSubType              ;\
@@ -254,7 +258,7 @@ typedef struct TU_ATTR_PACKED
 }cdc_desc_func_country_selection_t;
 
 #define cdc_desc_func_country_selection_n_t(no_country) \
-  struct TU_ATTR_PACKED {\
+  struct TU_ATTR_PACKED {            \
   uint8_t bLength                   ;\
   uint8_t bDescriptorType           ;\
   uint8_t bDescriptorSubType        ;\
@@ -277,26 +281,25 @@ typedef struct TU_ATTR_PACKED
   struct {
     uint8_t handle_call    : 1; ///< 0 - Device sends/receives call management information only over the Communications Class interface. 1 - Device can send/receive call management information over a Data Class interface.
     uint8_t send_recv_call : 1; ///< 0 - Device does not handle call management itself. 1 - Device handles call management itself.
-    uint8_t : 0;
+    uint8_t TU_RESERVED    : 6;
   } bmCapabilities;
 
   uint8_t bDataInterface;
 }cdc_desc_func_call_management_t;
 
-
 typedef struct TU_ATTR_PACKED
 {
   uint8_t support_comm_request                    : 1; ///< Device supports the request combination of Set_Comm_Feature, Clear_Comm_Feature, and Get_Comm_Feature.
   uint8_t support_line_request                    : 1; ///< Device supports the request combination of Set_Line_Coding, Set_Control_Line_State, Get_Line_Coding, and the notification Serial_State.
   uint8_t support_send_break                      : 1; ///< Device supports the request Send_Break
   uint8_t support_notification_network_connection : 1; ///< Device supports the notification Network_Connection.
-  uint8_t : 0;
+  uint8_t TU_RESERVED                             : 4;
 }cdc_acm_capability_t;
 
 TU_VERIFY_STATIC(sizeof(cdc_acm_capability_t) == 1, "mostly problem with compiler");
 
-/// \brief Abstract Control Management Functional Descriptor
-/// \details This functional descriptor describes the commands supported by by the Communications Class interface with SubClass code of \ref CDC_COMM_SUBCLASS_ABSTRACT_CONTROL_MODEL
+/// Abstract Control Management Functional Descriptor
+/// This functional descriptor describes the commands supported by by the Communications Class interface with SubClass code of \ref CDC_COMM_SUBCLASS_ABSTRACT_CONTROL_MODEL
 typedef struct TU_ATTR_PACKED
 {
   uint8_t bLength                  ; ///< Size of this descriptor in bytes.
@@ -316,7 +319,7 @@ typedef struct TU_ATTR_PACKED
     uint8_t require_pulse_setup   : 1; ///< Device requires extra Pulse_Setup request during pulse dialing sequence to disengage holding circuit.
     uint8_t support_aux_request   : 1; ///< Device supports the request combination of Set_Aux_Line_State, Ring_Aux_Jack, and notification Aux_Jack_Hook_State.
     uint8_t support_pulse_request : 1; ///< Device supports the request combination of Pulse_Setup, Send_Pulse, and Set_Pulse_Time.
-    uint8_t : 0;
+    uint8_t TU_RESERVED           : 5;
   } bmCapabilities;
 }cdc_desc_func_direct_line_management_t;
 
@@ -344,7 +347,7 @@ typedef struct TU_ATTR_PACKED
     uint8_t simple_mode           : 1;
     uint8_t standalone_mode       : 1;
     uint8_t computer_centric_mode : 1;
-    uint8_t : 0;
+    uint8_t TU_RESERVED           : 5;
   } bmCapabilities;
 }cdc_desc_func_telephone_operational_modes_t;
 
@@ -363,10 +366,11 @@ typedef struct TU_ATTR_PACKED
     uint32_t incoming_distinctive   : 1; ///< 0 : Reports only incoming ringing. 1 : Reports incoming distinctive ringing patterns.
     uint32_t dual_tone_multi_freq   : 1; ///< 0 : Cannot report dual tone multi-frequency (DTMF) digits input remotely over the telephone line. 1 : Can report DTMF digits input remotely over the telephone line.
     uint32_t line_state_change      : 1; ///< 0 : Does not support line state change notification. 1 : Does support line state change notification
-    uint32_t : 0;
+    uint32_t TU_RESERVED            : 26;
   } bmCapabilities;
 }cdc_desc_func_telephone_call_state_reporting_capabilities_t;
 
+// TODO remove
 static inline uint8_t cdc_functional_desc_typeof(uint8_t const * p_desc)
 {
   return p_desc[2];
@@ -394,7 +398,8 @@ typedef struct TU_ATTR_PACKED
 
 TU_VERIFY_STATIC(sizeof(cdc_line_control_state_t) == 2, "size is not correct");
 
-/** @} */
+TU_ATTR_PACKED_END  // End of all packed definitions
+TU_ATTR_BIT_FIELD_ORDER_END
 
 #ifdef __cplusplus
  }
diff --git a/src/class/cdc/cdc_device.c b/src/class/cdc/cdc_device.c
index c0de0cadd..e622bd616 100644
--- a/src/class/cdc/cdc_device.c
+++ b/src/class/cdc/cdc_device.c
@@ -28,12 +28,19 @@
 
 #if (TUSB_OPT_DEVICE_ENABLED && CFG_TUD_CDC)
 
-#include "cdc_device.h"
+#include "device/usbd.h"
 #include "device/usbd_pvt.h"
 
+#include "cdc_device.h"
+
 //--------------------------------------------------------------------+
 // MACRO CONSTANT TYPEDEF
 //--------------------------------------------------------------------+
+enum
+{
+  BULK_PACKET_SIZE = (TUD_OPT_HIGH_SPEED ? 512 : 64)
+};
+
 typedef struct
 {
   uint8_t itf_num;
@@ -61,8 +68,8 @@ typedef struct
 #endif
 
   // Endpoint Transfer buffer
-  CFG_TUSB_MEM_ALIGN uint8_t epout_buf[CFG_TUD_CDC_EPSIZE];
-  CFG_TUSB_MEM_ALIGN uint8_t epin_buf[CFG_TUD_CDC_EPSIZE];
+  CFG_TUSB_MEM_ALIGN uint8_t epout_buf[CFG_TUD_CDC_EP_BUFSIZE];
+  CFG_TUSB_MEM_ALIGN uint8_t epin_buf[CFG_TUD_CDC_EP_BUFSIZE];
 
 }cdcd_interface_t;
 
@@ -73,18 +80,30 @@ typedef struct
 //--------------------------------------------------------------------+
 CFG_TUSB_MEM_SECTION static cdcd_interface_t _cdcd_itf[CFG_TUD_CDC];
 
-static void _prep_out_transaction (uint8_t itf)
+static void _prep_out_transaction (cdcd_interface_t* p_cdc)
 {
-  cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
-
-  // skip if previous transfer not complete
-  if ( usbd_edpt_busy(TUD_OPT_RHPORT, p_cdc->ep_out) ) return;
+  uint8_t const rhport = TUD_OPT_RHPORT;
+  uint16_t available = tu_fifo_remaining(&p_cdc->rx_ff);
 
   // Prepare for incoming data but only allow what we can store in the ring buffer.
-  uint16_t max_read = tu_fifo_remaining(&p_cdc->rx_ff);
-  if ( max_read >= CFG_TUD_CDC_EPSIZE )
+  // TODO Actually we can still carry out the transfer, keeping count of received bytes
+  // and slowly move it to the FIFO when read().
+  // This pre-check reduces endpoint claiming
+  TU_VERIFY(available >= sizeof(p_cdc->epout_buf), );
+
+  // claim endpoint
+  TU_VERIFY(usbd_edpt_claim(rhport, p_cdc->ep_out), );
+
+  // fifo can be changed before endpoint is claimed
+  available = tu_fifo_remaining(&p_cdc->rx_ff);
+
+  if ( available >= sizeof(p_cdc->epout_buf) )
+  {
+    usbd_edpt_xfer(rhport, p_cdc->ep_out, p_cdc->epout_buf, sizeof(p_cdc->epout_buf));
+  }else
   {
-    usbd_edpt_xfer(TUD_OPT_RHPORT, p_cdc->ep_out, p_cdc->epout_buf, CFG_TUD_CDC_EPSIZE);
+    // Release endpoint since we don't make any transfer
+    usbd_edpt_release(rhport, p_cdc->ep_out);
   }
 }
 
@@ -123,20 +142,22 @@ uint32_t tud_cdc_n_available(uint8_t itf)
 
 uint32_t tud_cdc_n_read(uint8_t itf, void* buffer, uint32_t bufsize)
 {
-  uint32_t num_read = tu_fifo_read_n(&_cdcd_itf[itf].rx_ff, buffer, bufsize);
-  _prep_out_transaction(itf);
+  cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
+  uint32_t num_read = tu_fifo_read_n(&p_cdc->rx_ff, buffer, bufsize);
+  _prep_out_transaction(p_cdc);
   return num_read;
 }
 
-bool tud_cdc_n_peek(uint8_t itf, int pos, uint8_t* chr)
+bool tud_cdc_n_peek(uint8_t itf, uint8_t* chr)
 {
-  return tu_fifo_peek_at(&_cdcd_itf[itf].rx_ff, pos, chr);
+  return tu_fifo_peek(&_cdcd_itf[itf].rx_ff, chr);
 }
 
 void tud_cdc_n_read_flush (uint8_t itf)
 {
-  tu_fifo_clear(&_cdcd_itf[itf].rx_ff);
-  _prep_out_transaction(itf);
+  cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
+  tu_fifo_clear(&p_cdc->rx_ff);
+  _prep_out_transaction(p_cdc);
 }
 
 //--------------------------------------------------------------------+
@@ -144,32 +165,47 @@ void tud_cdc_n_read_flush (uint8_t itf)
 //--------------------------------------------------------------------+
 uint32_t tud_cdc_n_write(uint8_t itf, void const* buffer, uint32_t bufsize)
 {
-  uint16_t ret = tu_fifo_write_n(&_cdcd_itf[itf].tx_ff, buffer, bufsize);
+  cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
+  uint16_t ret = tu_fifo_write_n(&p_cdc->tx_ff, buffer, bufsize);
 
-#if 0 // TODO issue with circuitpython's REPL
-  // flush if queue more than endpoint size
-  if ( tu_fifo_count(&_cdcd_itf[itf].tx_ff) >= CFG_TUD_CDC_EPSIZE )
+  // flush if queue more than packet size
+  if ( tu_fifo_count(&p_cdc->tx_ff) >= BULK_PACKET_SIZE )
   {
     tud_cdc_n_write_flush(itf);
   }
-#endif
 
   return ret;
 }
 
-bool tud_cdc_n_write_flush (uint8_t itf)
+uint32_t tud_cdc_n_write_flush (uint8_t itf)
 {
   cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
-  TU_VERIFY( !usbd_edpt_busy(TUD_OPT_RHPORT, p_cdc->ep_in) ); // skip if previous transfer not complete
 
-  uint16_t count = tu_fifo_read_n(&_cdcd_itf[itf].tx_ff, p_cdc->epin_buf, CFG_TUD_CDC_EPSIZE);
+  // Skip if usb is not ready yet
+  TU_VERIFY( tud_ready(), 0 );
+
+  // No data to send
+  if ( !tu_fifo_count(&p_cdc->tx_ff) ) return 0;
+
+  uint8_t const rhport = TUD_OPT_RHPORT;
+
+  // Claim the endpoint
+  TU_VERIFY( usbd_edpt_claim(rhport, p_cdc->ep_in), 0 );
+
+  // Pull data from FIFO
+  uint16_t const count = tu_fifo_read_n(&p_cdc->tx_ff, p_cdc->epin_buf, sizeof(p_cdc->epin_buf));
+
   if ( count )
   {
-    TU_VERIFY( tud_cdc_n_connected(itf) ); // fifo is empty if not connected
-    TU_ASSERT( usbd_edpt_xfer(TUD_OPT_RHPORT, p_cdc->ep_in, p_cdc->epin_buf, count) );
+    TU_ASSERT( usbd_edpt_xfer(rhport, p_cdc->ep_in, p_cdc->epin_buf, count), 0 );
+    return count;
+  }else
+  {
+    // Release endpoint since we don't make any transfer
+    // Note: data is dropped if terminal is not connected
+    usbd_edpt_release(rhport, p_cdc->ep_in);
+    return 0;
   }
-
-  return true;
 }
 
 uint32_t tud_cdc_n_write_available (uint8_t itf)
@@ -177,6 +213,10 @@ uint32_t tud_cdc_n_write_available (uint8_t itf)
   return tu_fifo_remaining(&_cdcd_itf[itf].tx_ff);
 }
 
+bool tud_cdc_n_write_clear (uint8_t itf)
+{
+  return tu_fifo_clear(&_cdcd_itf[itf].tx_ff);
+}
 
 //--------------------------------------------------------------------+
 // USBD Driver API
@@ -192,18 +232,22 @@ void cdcd_init(void)
     p_cdc->wanted_char = -1;
 
     // default line coding is : stop bit = 1, parity = none, data bits = 8
-    p_cdc->line_coding.bit_rate = 115200;
+    p_cdc->line_coding.bit_rate  = 115200;
     p_cdc->line_coding.stop_bits = 0;
     p_cdc->line_coding.parity    = 0;
     p_cdc->line_coding.data_bits = 8;
 
-    // config fifo
-    tu_fifo_config(&p_cdc->rx_ff, p_cdc->rx_ff_buf, CFG_TUD_CDC_RX_BUFSIZE, 1, false);
-    tu_fifo_config(&p_cdc->tx_ff, p_cdc->tx_ff_buf, CFG_TUD_CDC_TX_BUFSIZE, 1, false);
+    // Config RX fifo
+    tu_fifo_config(&p_cdc->rx_ff, p_cdc->rx_ff_buf, TU_ARRAY_SIZE(p_cdc->rx_ff_buf), 1, false);
+
+    // Config TX fifo as overwritable at initialization and will be changed to non-overwritable
+    // if terminal supports DTR bit. Without DTR we do not know if data is actually polled by terminal.
+    // In this way, the most current data is prioritized.
+    tu_fifo_config(&p_cdc->tx_ff, p_cdc->tx_ff_buf, TU_ARRAY_SIZE(p_cdc->tx_ff_buf), 1, true);
 
 #if CFG_FIFO_MUTEX
-    tu_fifo_config_mutex(&p_cdc->rx_ff, osal_mutex_create(&p_cdc->rx_ff_mutex));
-    tu_fifo_config_mutex(&p_cdc->tx_ff, osal_mutex_create(&p_cdc->tx_ff_mutex));
+    tu_fifo_config_mutex(&p_cdc->rx_ff, NULL, osal_mutex_create(&p_cdc->rx_ff_mutex));
+    tu_fifo_config_mutex(&p_cdc->tx_ff, osal_mutex_create(&p_cdc->tx_ff_mutex), NULL);
 #endif
   }
 }
@@ -214,25 +258,24 @@ void cdcd_reset(uint8_t rhport)
 
   for(uint8_t i=0; i<CFG_TUD_CDC; i++)
   {
-    tu_memclr(&_cdcd_itf[i], ITF_MEM_RESET_SIZE);
-    tu_fifo_clear(&_cdcd_itf[i].rx_ff);
-    tu_fifo_clear(&_cdcd_itf[i].tx_ff);
+    cdcd_interface_t* p_cdc = &_cdcd_itf[i];
+
+    tu_memclr(p_cdc, ITF_MEM_RESET_SIZE);
+    tu_fifo_clear(&p_cdc->rx_ff);
+    tu_fifo_clear(&p_cdc->tx_ff);
+    tu_fifo_set_overwritable(&p_cdc->tx_ff, true);
   }
 }
 
-bool cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t *p_length)
+uint16_t cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t max_len)
 {
   // Only support ACM subclass
-  TU_ASSERT ( CDC_COMM_SUBCLASS_ABSTRACT_CONTROL_MODEL == itf_desc->bInterfaceSubClass);
-
-  // Only support AT commands, no protocol and vendor specific commands.
-  TU_ASSERT(tu_within(CDC_COMM_PROTOCOL_NONE, itf_desc->bInterfaceProtocol, CDC_COMM_PROTOCOL_ATCOMMAND_CDMA) ||
-            itf_desc->bInterfaceProtocol == 0xff);
+  TU_VERIFY( TUSB_CLASS_CDC                           == itf_desc->bInterfaceClass &&
+             CDC_COMM_SUBCLASS_ABSTRACT_CONTROL_MODEL == itf_desc->bInterfaceSubClass, 0);
 
   // Find available interface
   cdcd_interface_t * p_cdc = NULL;
-  uint8_t cdc_id;
-  for(cdc_id=0; cdc_id<CFG_TUD_CDC; cdc_id++)
+  for(uint8_t cdc_id=0; cdc_id<CFG_TUD_CDC; cdc_id++)
   {
     if ( _cdcd_itf[cdc_id].ep_in == 0 )
     {
@@ -240,83 +283,57 @@ bool cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t
       break;
     }
   }
-  TU_ASSERT(p_cdc);
+  TU_ASSERT(p_cdc, 0);
 
   //------------- Control Interface -------------//
   p_cdc->itf_num = itf_desc->bInterfaceNumber;
 
+  uint16_t drv_len = sizeof(tusb_desc_interface_t);
   uint8_t const * p_desc = tu_desc_next( itf_desc );
-  (*p_length) = sizeof(tusb_desc_interface_t);
 
   // Communication Functional Descriptors
-  while ( TUSB_DESC_CS_INTERFACE == tu_desc_type(p_desc) )
+  while ( TUSB_DESC_CS_INTERFACE == tu_desc_type(p_desc) && drv_len <= max_len )
   {
-    (*p_length) += tu_desc_len(p_desc);
-    p_desc = tu_desc_next(p_desc);
+    drv_len += tu_desc_len(p_desc);
+    p_desc   = tu_desc_next(p_desc);
   }
 
   if ( TUSB_DESC_ENDPOINT == tu_desc_type(p_desc) )
   {
-    // notification endpoint if any
-    TU_ASSERT( dcd_edpt_open(rhport, (tusb_desc_endpoint_t const *) p_desc) );
+    // notification endpoint
+    tusb_desc_endpoint_t const * desc_ep = (tusb_desc_endpoint_t const *) p_desc;
 
-    p_cdc->ep_notif = ((tusb_desc_endpoint_t const *) p_desc)->bEndpointAddress;
+    TU_ASSERT( usbd_edpt_open(rhport, desc_ep), 0 );
+    p_cdc->ep_notif = desc_ep->bEndpointAddress;
 
-    (*p_length) += p_desc[DESC_OFFSET_LEN];
-    p_desc = tu_desc_next(p_desc);
+    drv_len += tu_desc_len(p_desc);
+    p_desc   = tu_desc_next(p_desc);
   }
 
   //------------- Data Interface (if any) -------------//
-  if ( (TUSB_DESC_INTERFACE == p_desc[DESC_OFFSET_TYPE]) &&
+  if ( (TUSB_DESC_INTERFACE == tu_desc_type(p_desc)) &&
        (TUSB_CLASS_CDC_DATA == ((tusb_desc_interface_t const *) p_desc)->bInterfaceClass) )
   {
     // next to endpoint descriptor
-    p_desc = tu_desc_next(p_desc);
+    drv_len += tu_desc_len(p_desc);
+    p_desc   = tu_desc_next(p_desc);
 
     // Open endpoint pair
-    TU_ASSERT( usbd_open_edpt_pair(rhport, p_desc, 2, TUSB_XFER_BULK, &p_cdc->ep_out, &p_cdc->ep_in) );
+    TU_ASSERT( usbd_open_edpt_pair(rhport, p_desc, 2, TUSB_XFER_BULK, &p_cdc->ep_out, &p_cdc->ep_in), 0 );
 
-    (*p_length) += sizeof(tusb_desc_interface_t) + 2*sizeof(tusb_desc_endpoint_t);
+    drv_len += 2*sizeof(tusb_desc_endpoint_t);
   }
 
   // Prepare for incoming data
-  _prep_out_transaction(cdc_id);
-
-  return true;
-}
-
-// Invoked when class request DATA stage is finished.
-// return false to stall control endpoint (e.g Host send non-sense DATA)
-bool cdcd_control_complete(uint8_t rhport, tusb_control_request_t const * request)
-{
-  (void) rhport;
-
-  //------------- Class Specific Request -------------//
-  TU_VERIFY (request->bmRequestType_bit.type == TUSB_REQ_TYPE_CLASS);
-
-  uint8_t itf = 0;
-  cdcd_interface_t* p_cdc = _cdcd_itf;
-
-  // Identify which interface to use
-  for ( ; ; itf++, p_cdc++)
-  {
-    if (itf >= TU_ARRAY_SIZE(_cdcd_itf)) return false;
-
-    if ( p_cdc->itf_num == request->wIndex ) break;
-  }
+  _prep_out_transaction(p_cdc);
 
-  // Invoke callback
-  if ( CDC_REQUEST_SET_LINE_CODING == request->bRequest )
-  {
-    if ( tud_cdc_line_coding_cb ) tud_cdc_line_coding_cb(itf, &p_cdc->line_coding);
-  }
-
-  return true;
+  return drv_len;
 }
 
-// Handle class control request
+// Invoked when a control transfer occurred on an interface of this class
+// Driver response accordingly to the request and the transfer stage (setup/data/ack)
 // return false to stall control endpoint (e.g unsupported request)
-bool cdcd_control_request(uint8_t rhport, tusb_control_request_t const * request)
+bool cdcd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t const * request)
 {
   // Handle class request only
   TU_VERIFY(request->bmRequestType_bit.type == TUSB_REQ_TYPE_CLASS);
@@ -335,25 +352,61 @@ bool cdcd_control_request(uint8_t rhport, tusb_control_request_t const * request
   switch ( request->bRequest )
   {
     case CDC_REQUEST_SET_LINE_CODING:
-      tud_control_xfer(rhport, request, &p_cdc->line_coding, sizeof(cdc_line_coding_t));
+      if (stage == CONTROL_STAGE_SETUP)
+      {
+        TU_LOG2("  Set Line Coding\r\n");
+        tud_control_xfer(rhport, request, &p_cdc->line_coding, sizeof(cdc_line_coding_t));
+      }
+      else if ( stage == CONTROL_STAGE_ACK)
+      {
+        if ( tud_cdc_line_coding_cb ) tud_cdc_line_coding_cb(itf, &p_cdc->line_coding);
+      }
     break;
 
     case CDC_REQUEST_GET_LINE_CODING:
-      tud_control_xfer(rhport, request, &p_cdc->line_coding, sizeof(cdc_line_coding_t));
+      if (stage == CONTROL_STAGE_SETUP)
+      {
+        TU_LOG2("  Get Line Coding\r\n");
+        tud_control_xfer(rhport, request, &p_cdc->line_coding, sizeof(cdc_line_coding_t));
+      }
     break;
 
     case CDC_REQUEST_SET_CONTROL_LINE_STATE:
-      // CDC PSTN v1.2 section 6.3.12
-      // Bit 0: Indicates if DTE is present or not.
-      //        This signal corresponds to V.24 signal 108/2 and RS-232 signal DTR (Data Terminal Ready)
-      // Bit 1: Carrier control for half-duplex modems.
-      //        This signal corresponds to V.24 signal 105 and RS-232 signal RTS (Request to Send)
-      p_cdc->line_state = (uint8_t) request->wValue;
+      if (stage == CONTROL_STAGE_SETUP)
+      {
+        tud_control_status(rhport, request);
+      }
+      else if (stage == CONTROL_STAGE_ACK)
+      {
+        // CDC PSTN v1.2 section 6.3.12
+        // Bit 0: Indicates if DTE is present or not.
+        //        This signal corresponds to V.24 signal 108/2 and RS-232 signal DTR (Data Terminal Ready)
+        // Bit 1: Carrier control for half-duplex modems.
+        //        This signal corresponds to V.24 signal 105 and RS-232 signal RTS (Request to Send)
+        bool const dtr = tu_bit_test(request->wValue, 0);
+        bool const rts = tu_bit_test(request->wValue, 1);
 
-      tud_control_status(rhport, request);
+        p_cdc->line_state = (uint8_t) request->wValue;
+        
+        // Disable fifo overwriting if DTR bit is set
+        tu_fifo_set_overwritable(&p_cdc->tx_ff, !dtr);
 
-      // Invoke callback
-      if ( tud_cdc_line_state_cb) tud_cdc_line_state_cb(itf, tu_bit_test(request->wValue, 0), tu_bit_test(request->wValue, 1));
+        TU_LOG2("  Set Control Line State: DTR = %d, RTS = %d\r\n", dtr, rts);
+
+        // Invoke callback
+        if ( tud_cdc_line_state_cb ) tud_cdc_line_state_cb(itf, dtr, rts);
+      }
+    break;
+    case CDC_REQUEST_SEND_BREAK:
+      if (stage == CONTROL_STAGE_SETUP)
+      {
+        tud_control_status(rhport, request);
+      }
+      else if (stage == CONTROL_STAGE_ACK)
+      {
+        TU_LOG2("  Send Break\r\n");
+        if ( tud_cdc_send_break_cb ) tud_cdc_send_break_cb(itf, request->wValue);
+      }
     break;
 
     default: return false; // stall unsupported request
@@ -364,48 +417,64 @@ bool cdcd_control_request(uint8_t rhport, tusb_control_request_t const * request
 
 bool cdcd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes)
 {
-  (void) rhport;
   (void) result;
 
-  uint8_t itf = 0;
-  cdcd_interface_t* p_cdc = _cdcd_itf;
+  uint8_t itf;
+  cdcd_interface_t* p_cdc;
 
   // Identify which interface to use
-  for ( ; ; itf++, p_cdc++)
+  for (itf = 0; itf < CFG_TUD_CDC; itf++)
   {
-    if (itf >= TU_ARRAY_SIZE(_cdcd_itf)) return false;
-
+    p_cdc = &_cdcd_itf[itf];
     if ( ( ep_addr == p_cdc->ep_out ) || ( ep_addr == p_cdc->ep_in ) ) break;
   }
+  TU_ASSERT(itf < CFG_TUD_CDC);
 
   // Received new data
   if ( ep_addr == p_cdc->ep_out )
   {
-    for(uint32_t i=0; i<xferred_bytes; i++)
+    tu_fifo_write_n(&p_cdc->rx_ff, &p_cdc->epout_buf, xferred_bytes);
+    
+    // Check for wanted char and invoke callback if needed
+    if ( tud_cdc_rx_wanted_cb && (((signed char) p_cdc->wanted_char) != -1) )
     {
-      tu_fifo_write(&p_cdc->rx_ff, &p_cdc->epout_buf[i]);
-
-      // Check for wanted char and invoke callback if needed
-      if ( tud_cdc_rx_wanted_cb && ( ((signed char) p_cdc->wanted_char) != -1 ) && ( p_cdc->wanted_char == p_cdc->epout_buf[i] ) )
+      for ( uint32_t i = 0; i < xferred_bytes; i++ )
       {
-        tud_cdc_rx_wanted_cb(itf, p_cdc->wanted_char);
+        if ( (p_cdc->wanted_char == p_cdc->epout_buf[i]) && !tu_fifo_empty(&p_cdc->rx_ff) )
+        {
+          tud_cdc_rx_wanted_cb(itf, p_cdc->wanted_char);
+        }
       }
     }
-
+    
     // invoke receive callback (if there is still data)
-    if (tud_cdc_rx_cb && tu_fifo_count(&p_cdc->rx_ff) ) tud_cdc_rx_cb(itf);
-
+    if (tud_cdc_rx_cb && !tu_fifo_empty(&p_cdc->rx_ff) ) tud_cdc_rx_cb(itf);
+    
     // prepare for OUT transaction
-    _prep_out_transaction(itf);
+    _prep_out_transaction(p_cdc);
   }
+  
+  // Data sent to host, we continue to fetch from tx fifo to send.
+  // Note: This will cause incorrect baudrate set in line coding.
+  //       Though maybe the baudrate is not really important !!!
+  if ( ep_addr == p_cdc->ep_in )
+  {
+    // invoke transmit callback to possibly refill tx fifo
+    if ( tud_cdc_tx_complete_cb ) tud_cdc_tx_complete_cb(itf);
 
-  // Data sent to host, we could continue to fetch data tx fifo to send.
-  // But it will cause incorrect baudrate set in line coding.
-  // Though maybe the baudrate is not really important !!!
-//  if ( ep_addr == p_cdc->ep_in )
-//  {
-//
-//  }
+    if ( 0 == tud_cdc_n_write_flush(itf) )
+    {
+      // If there is no data left, a ZLP should be sent if
+      // xferred_bytes is multiple of EP Packet size and not zero
+      if ( !tu_fifo_count(&p_cdc->tx_ff) && xferred_bytes && (0 == (xferred_bytes & (BULK_PACKET_SIZE-1))) )
+      {
+        if ( usbd_edpt_claim(rhport, p_cdc->ep_in) )
+        {
+          usbd_edpt_xfer(rhport, p_cdc->ep_in, NULL, 0);
+        }
+      }
+    }
+  }
 
   // nothing to do with notif endpoint for now
 
diff --git a/src/class/cdc/cdc_device.h b/src/class/cdc/cdc_device.h
index 969ec7f99..7ff757add 100644
--- a/src/class/cdc/cdc_device.h
+++ b/src/class/cdc/cdc_device.h
@@ -28,14 +28,18 @@
 #define _TUSB_CDC_DEVICE_H_
 
 #include "common/tusb_common.h"
-#include "device/usbd.h"
 #include "cdc.h"
 
 //--------------------------------------------------------------------+
 // Class Driver Configuration
 //--------------------------------------------------------------------+
-#ifndef CFG_TUD_CDC_EPSIZE
-#define CFG_TUD_CDC_EPSIZE 64
+#if !defined(CFG_TUD_CDC_EP_BUFSIZE) && defined(CFG_TUD_CDC_EPSIZE)
+  #warning CFG_TUD_CDC_EPSIZE is renamed to CFG_TUD_CDC_EP_BUFSIZE, please update to use the new name
+  #define CFG_TUD_CDC_EP_BUFSIZE    CFG_TUD_CDC_EPSIZE
+#endif
+
+#ifndef CFG_TUD_CDC_EP_BUFSIZE
+  #define CFG_TUD_CDC_EP_BUFSIZE    (TUD_OPT_HIGH_SPEED ? 512 : 64)
 #endif
 
 #ifdef __cplusplus
@@ -48,28 +52,60 @@
  *  @{ */
 
 //--------------------------------------------------------------------+
-// Application API (Multiple Interfaces)
+// Application API (Multiple Ports)
 // CFG_TUD_CDC > 1
 //--------------------------------------------------------------------+
+
+// Check if terminal is connected to this port
 bool     tud_cdc_n_connected       (uint8_t itf);
+
+// Get current line state. Bit 0:  DTR (Data Terminal Ready), Bit 1: RTS (Request to Send)
 uint8_t  tud_cdc_n_get_line_state  (uint8_t itf);
+
+// Get current line encoding: bit rate, stop bits parity etc ..
 void     tud_cdc_n_get_line_coding (uint8_t itf, cdc_line_coding_t* coding);
+
+// Set special character that will trigger tud_cdc_rx_wanted_cb() callback on receiving
 void     tud_cdc_n_set_wanted_char (uint8_t itf, char wanted);
 
+// Get the number of bytes available for reading
 uint32_t tud_cdc_n_available       (uint8_t itf);
+
+// Read received bytes
 uint32_t tud_cdc_n_read            (uint8_t itf, void* buffer, uint32_t bufsize);
+
+// Read a byte, return -1 if there is none
+static inline
+int32_t  tud_cdc_n_read_char       (uint8_t itf);
+
+// Clear the received FIFO
 void     tud_cdc_n_read_flush      (uint8_t itf);
-bool     tud_cdc_n_peek            (uint8_t itf, int pos, uint8_t* u8);
-static inline int32_t tud_cdc_n_read_char (uint8_t itf);
 
+// Get a byte from FIFO at the specified position without removing it
+bool     tud_cdc_n_peek            (uint8_t itf, uint8_t* u8);
+
+// Write bytes to TX FIFO, data may remain in the FIFO for a while
 uint32_t tud_cdc_n_write           (uint8_t itf, void const* buffer, uint32_t bufsize);
-bool     tud_cdc_n_write_flush     (uint8_t itf);
+
+// Write a byte
+static inline
+uint32_t tud_cdc_n_write_char      (uint8_t itf, char ch);
+
+// Write a null-terminated string
+static inline
+uint32_t tud_cdc_n_write_str       (uint8_t itf, char const* str);
+
+// Force sending data if possible, return number of forced bytes
+uint32_t tud_cdc_n_write_flush     (uint8_t itf);
+
+// Return the number of bytes (characters) available for writing to TX FIFO buffer in a single n_write operation.
 uint32_t tud_cdc_n_write_available (uint8_t itf);
-static inline uint32_t tud_cdc_n_write_char (uint8_t itf, char ch);
-static inline uint32_t tud_cdc_n_write_str  (uint8_t itf, char const* str);
+
+// Clear the transmit FIFO
+bool tud_cdc_n_write_clear (uint8_t itf);
 
 //--------------------------------------------------------------------+
-// Application API (Interface0)
+// Application API (Single Port)
 //--------------------------------------------------------------------+
 static inline bool     tud_cdc_connected       (void);
 static inline uint8_t  tud_cdc_get_line_state  (void);
@@ -80,13 +116,14 @@ static inline uint32_t tud_cdc_available       (void);
 static inline int32_t  tud_cdc_read_char       (void);
 static inline uint32_t tud_cdc_read            (void* buffer, uint32_t bufsize);
 static inline void     tud_cdc_read_flush      (void);
-static inline bool     tud_cdc_peek            (int pos, uint8_t* u8);
+static inline bool     tud_cdc_peek            (uint8_t* u8);
 
 static inline uint32_t tud_cdc_write_char      (char ch);
 static inline uint32_t tud_cdc_write           (void const* buffer, uint32_t bufsize);
 static inline uint32_t tud_cdc_write_str       (char const* str);
-static inline bool     tud_cdc_write_flush     (void);
+static inline uint32_t tud_cdc_write_flush     (void);
 static inline uint32_t tud_cdc_write_available (void);
+static inline bool     tud_cdc_write_clear     (void);
 
 //--------------------------------------------------------------------+
 // Application Callback API (weak is optional)
@@ -98,12 +135,18 @@ TU_ATTR_WEAK void tud_cdc_rx_cb(uint8_t itf);
 // Invoked when received `wanted_char`
 TU_ATTR_WEAK void tud_cdc_rx_wanted_cb(uint8_t itf, char wanted_char);
 
+// Invoked when space becomes available in TX buffer
+TU_ATTR_WEAK void tud_cdc_tx_complete_cb(uint8_t itf);
+
 // Invoked when line state DTR & RTS are changed via SET_CONTROL_LINE_STATE
 TU_ATTR_WEAK void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts);
 
 // Invoked when line coding is change via SET_LINE_CODING
 TU_ATTR_WEAK void tud_cdc_line_coding_cb(uint8_t itf, cdc_line_coding_t const* p_line_coding);
 
+// Invoked when received send break
+TU_ATTR_WEAK void tud_cdc_send_break_cb(uint8_t itf, uint16_t duration_ms);
+
 //--------------------------------------------------------------------+
 // Inline Functions
 //--------------------------------------------------------------------+
@@ -163,9 +206,9 @@ static inline void tud_cdc_read_flush (void)
   tud_cdc_n_read_flush(0);
 }
 
-static inline bool tud_cdc_peek (int pos, uint8_t* u8)
+static inline bool tud_cdc_peek (uint8_t* u8)
 {
-  return tud_cdc_n_peek(0, pos, u8);
+  return tud_cdc_n_peek(0, u8);
 }
 
 static inline uint32_t tud_cdc_write_char (char ch)
@@ -183,7 +226,7 @@ static inline uint32_t tud_cdc_write_str (char const* str)
   return tud_cdc_n_write_str(0, str);
 }
 
-static inline bool tud_cdc_write_flush (void)
+static inline uint32_t tud_cdc_write_flush (void)
 {
   return tud_cdc_n_write_flush(0);
 }
@@ -193,18 +236,22 @@ static inline uint32_t tud_cdc_write_available(void)
   return tud_cdc_n_write_available(0);
 }
 
+static inline bool tud_cdc_write_clear(void)
+{
+  return tud_cdc_n_write_clear(0);
+}
+
 /** @} */
 /** @} */
 
 //--------------------------------------------------------------------+
 // INTERNAL USBD-CLASS DRIVER API
 //--------------------------------------------------------------------+
-void cdcd_init             (void);
-void cdcd_reset            (uint8_t rhport);
-bool cdcd_open             (uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t *p_length);
-bool cdcd_control_request  (uint8_t rhport, tusb_control_request_t const * request);
-bool cdcd_control_complete (uint8_t rhport, tusb_control_request_t const * request);
-bool cdcd_xfer_cb          (uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes);
+void     cdcd_init            (void);
+void     cdcd_reset           (uint8_t rhport);
+uint16_t cdcd_open            (uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t max_len);
+bool     cdcd_control_xfer_cb (uint8_t rhport, uint8_t stage, tusb_control_request_t const * request);
+bool     cdcd_xfer_cb         (uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes);
 
 #ifdef __cplusplus
  }
diff --git a/src/class/cdc/cdc_host.c b/src/class/cdc/cdc_host.c
index 595e7fd62..35b8de3b1 100644
--- a/src/class/cdc/cdc_host.c
+++ b/src/class/cdc/cdc_host.c
@@ -28,7 +28,9 @@
 
 #if (TUSB_OPT_HOST_ENABLED && CFG_TUH_CDC)
 
-#include "common/tusb_common.h"
+#include "host/usbh.h"
+#include "host/usbh_classdriver.h"
+
 #include "cdc_host.h"
 
 //--------------------------------------------------------------------+
@@ -51,9 +53,14 @@ typedef struct {
 //--------------------------------------------------------------------+
 static cdch_data_t cdch_data[CFG_TUSB_HOST_DEVICE_MAX];
 
+static inline cdch_data_t* get_itf(uint8_t dev_addr)
+{
+  return &cdch_data[dev_addr-1];
+}
+
 bool tuh_cdc_mounted(uint8_t dev_addr)
 {
-  cdch_data_t* cdc = &cdch_data[dev_addr-1];
+  cdch_data_t* cdc = get_itf(dev_addr);
   return cdc->ep_in && cdc->ep_out;
 }
 
@@ -61,18 +68,18 @@ bool tuh_cdc_is_busy(uint8_t dev_addr, cdc_pipeid_t pipeid)
 {
   if ( !tuh_cdc_mounted(dev_addr) ) return false;
 
-  cdch_data_t const * p_cdc = &cdch_data[dev_addr-1];
+  cdch_data_t const * p_cdc = get_itf(dev_addr);
 
   switch (pipeid)
   {
     case CDC_PIPE_NOTIFICATION:
-      return hcd_edpt_busy(dev_addr, p_cdc->ep_notif );
+      return usbh_edpt_busy(dev_addr, p_cdc->ep_notif );
 
     case CDC_PIPE_DATA_IN:
-      return hcd_edpt_busy(dev_addr, p_cdc->ep_in );
+      return usbh_edpt_busy(dev_addr, p_cdc->ep_in );
 
     case CDC_PIPE_DATA_OUT:
-      return hcd_edpt_busy(dev_addr, p_cdc->ep_out );
+      return usbh_edpt_busy(dev_addr, p_cdc->ep_out );
 
     default:
       return false;
@@ -86,30 +93,52 @@ bool tuh_cdc_serial_is_mounted(uint8_t dev_addr)
 {
   // TODO consider all AT Command as serial candidate
   return tuh_cdc_mounted(dev_addr)                                         &&
-      (CDC_COMM_PROTOCOL_ATCOMMAND <= cdch_data[dev_addr-1].itf_protocol) &&
       (cdch_data[dev_addr-1].itf_protocol <= CDC_COMM_PROTOCOL_ATCOMMAND_CDMA);
 }
 
 bool tuh_cdc_send(uint8_t dev_addr, void const * p_data, uint32_t length, bool is_notify)
 {
+  (void) is_notify;
   TU_VERIFY( tuh_cdc_mounted(dev_addr) );
   TU_VERIFY( p_data != NULL && length, TUSB_ERROR_INVALID_PARA);
 
   uint8_t const ep_out = cdch_data[dev_addr-1].ep_out;
-  if ( hcd_edpt_busy(dev_addr, ep_out) ) return false;
+  if ( usbh_edpt_busy(dev_addr, ep_out) ) return false;
 
-  return hcd_pipe_xfer(dev_addr, ep_out, (void *) p_data, length, is_notify);
+  return usbh_edpt_xfer(dev_addr, ep_out, (void *) p_data, length);
 }
 
 bool tuh_cdc_receive(uint8_t dev_addr, void * p_buffer, uint32_t length, bool is_notify)
 {
+  (void) is_notify;
   TU_VERIFY( tuh_cdc_mounted(dev_addr) );
   TU_VERIFY( p_buffer != NULL && length, TUSB_ERROR_INVALID_PARA);
 
   uint8_t const ep_in = cdch_data[dev_addr-1].ep_in;
-  if ( hcd_edpt_busy(dev_addr, ep_in) ) return false;
+  if ( usbh_edpt_busy(dev_addr, ep_in) ) return false;
+
+  return usbh_edpt_xfer(dev_addr, ep_in, p_buffer, length);
+}
+
+bool tuh_cdc_set_control_line_state(uint8_t dev_addr, bool dtr, bool rts, tuh_control_complete_cb_t complete_cb)
+{
+  cdch_data_t const * p_cdc = get_itf(dev_addr);
+  tusb_control_request_t const request =
+  {
+    .bmRequestType_bit =
+    {
+      .recipient = TUSB_REQ_RCPT_INTERFACE,
+      .type      = TUSB_REQ_TYPE_CLASS,
+      .direction = TUSB_DIR_OUT
+    },
+    .bRequest = CDC_REQUEST_SET_CONTROL_LINE_STATE,
+    .wValue   = (rts ? 2 : 0) | (dtr ? 1 : 0),
+    .wIndex   = p_cdc->itf_num,
+    .wLength  = 0
+  };
 
-  return hcd_pipe_xfer(dev_addr, ep_in, p_buffer, length, is_notify);
+  TU_ASSERT( tuh_control_xfer(dev_addr, &request, NULL, complete_cb) );
+  return true;
 }
 
 //--------------------------------------------------------------------+
@@ -120,29 +149,27 @@ void cdch_init(void)
   tu_memclr(cdch_data, sizeof(cdch_data_t)*CFG_TUSB_HOST_DEVICE_MAX);
 }
 
-bool cdch_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *itf_desc, uint16_t *p_length)
+bool cdch_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *itf_desc, uint16_t max_len)
 {
-  // Only support ACM
-  TU_VERIFY( CDC_COMM_SUBCLASS_ABSTRACT_CONTROL_MODEL == itf_desc->bInterfaceSubClass);
-
-  // Only support AT commands, no protocol and vendor specific commands.
-  TU_VERIFY(tu_within(CDC_COMM_PROTOCOL_NONE, itf_desc->bInterfaceProtocol, CDC_COMM_PROTOCOL_ATCOMMAND_CDMA) ||
-            0xff == itf_desc->bInterfaceProtocol);
+  (void) max_len;
 
-  uint8_t const * p_desc;
-  cdch_data_t * p_cdc;
+  // Only support ACM subclass
+  // Protocol 0xFF can be RNDIS device for windows XP
+  TU_VERIFY( TUSB_CLASS_CDC                           == itf_desc->bInterfaceClass &&
+             CDC_COMM_SUBCLASS_ABSTRACT_CONTROL_MODEL == itf_desc->bInterfaceSubClass &&
+             0xFF                                     != itf_desc->bInterfaceProtocol);
 
-  p_desc = tu_desc_next(itf_desc);
-  p_cdc  = &cdch_data[dev_addr-1];
+  cdch_data_t * p_cdc = get_itf(dev_addr);
 
-  p_cdc->itf_num   = itf_desc->bInterfaceNumber;
-  p_cdc->itf_protocol = itf_desc->bInterfaceProtocol; // TODO 0xff is consider as rndis candidate, other is virtual Com
+  p_cdc->itf_num      = itf_desc->bInterfaceNumber;
+  p_cdc->itf_protocol = itf_desc->bInterfaceProtocol;
 
   //------------- Communication Interface -------------//
-  (*p_length) = sizeof(tusb_desc_interface_t);
+  uint16_t drv_len = tu_desc_len(itf_desc);
+  uint8_t const * p_desc = tu_desc_next(itf_desc);
 
   // Communication Functional Descriptors
-  while( TUSB_DESC_CS_INTERFACE == p_desc[DESC_OFFSET_TYPE] )
+  while( TUSB_DESC_CS_INTERFACE == tu_desc_type(p_desc) && drv_len <= max_len )
   {
     if ( CDC_FUNC_DESC_ABSTRACT_CONTROL_MANAGEMENT == cdc_functional_desc_typeof(p_desc) )
     {
@@ -150,75 +177,70 @@ bool cdch_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *it
       p_cdc->acm_capability = ((cdc_desc_func_acm_t const *) p_desc)->bmCapabilities;
     }
 
-    (*p_length) += p_desc[DESC_OFFSET_LEN];
+    drv_len += tu_desc_len(p_desc);
     p_desc = tu_desc_next(p_desc);
   }
 
-  if ( TUSB_DESC_ENDPOINT == p_desc[DESC_OFFSET_TYPE])
+  if ( TUSB_DESC_ENDPOINT == tu_desc_type(p_desc) )
   {
     // notification endpoint
-    tusb_desc_endpoint_t const * ep_desc = (tusb_desc_endpoint_t const *) p_desc;
+    tusb_desc_endpoint_t const * desc_ep = (tusb_desc_endpoint_t const *) p_desc;
 
-    TU_ASSERT( hcd_edpt_open(rhport, dev_addr, ep_desc) );
-    p_cdc->ep_notif = ep_desc->bEndpointAddress;
+    TU_ASSERT( usbh_edpt_open(rhport, dev_addr, desc_ep) );
+    p_cdc->ep_notif = desc_ep->bEndpointAddress;
 
-    (*p_length) += p_desc[DESC_OFFSET_LEN];
+    drv_len += tu_desc_len(p_desc);
     p_desc = tu_desc_next(p_desc);
   }
 
   //------------- Data Interface (if any) -------------//
-  if ( (TUSB_DESC_INTERFACE == p_desc[DESC_OFFSET_TYPE]) &&
+  if ( (TUSB_DESC_INTERFACE == tu_desc_type(p_desc)) &&
        (TUSB_CLASS_CDC_DATA == ((tusb_desc_interface_t const *) p_desc)->bInterfaceClass) )
   {
-    (*p_length) += p_desc[DESC_OFFSET_LEN];
+    // next to endpoint descriptor
+    drv_len += tu_desc_len(p_desc);
     p_desc = tu_desc_next(p_desc);
 
     // data endpoints expected to be in pairs
     for(uint32_t i=0; i<2; i++)
     {
-      tusb_desc_endpoint_t const *ep_desc = (tusb_desc_endpoint_t const *) p_desc;
-      TU_ASSERT(TUSB_DESC_ENDPOINT == ep_desc->bDescriptorType);
-      TU_ASSERT(TUSB_XFER_BULK == ep_desc->bmAttributes.xfer);
+      tusb_desc_endpoint_t const *desc_ep = (tusb_desc_endpoint_t const *) p_desc;
+      TU_ASSERT(TUSB_DESC_ENDPOINT == desc_ep->bDescriptorType && TUSB_XFER_BULK == desc_ep->bmAttributes.xfer);
 
-      TU_ASSERT(hcd_edpt_open(rhport, dev_addr, ep_desc));
+      TU_ASSERT(usbh_edpt_open(rhport, dev_addr, desc_ep));
 
-      if ( tu_edpt_dir(ep_desc->bEndpointAddress) ==  TUSB_DIR_IN )
+      if ( tu_edpt_dir(desc_ep->bEndpointAddress) == TUSB_DIR_IN )
       {
-        p_cdc->ep_in = ep_desc->bEndpointAddress;
+        p_cdc->ep_in = desc_ep->bEndpointAddress;
       }else
       {
-        p_cdc->ep_out = ep_desc->bEndpointAddress;
+        p_cdc->ep_out = desc_ep->bEndpointAddress;
       }
 
-      (*p_length) += p_desc[DESC_OFFSET_LEN];
+      drv_len += tu_desc_len(p_desc);
       p_desc = tu_desc_next( p_desc );
     }
   }
 
-  // FIXME move to seperate API : connect
-  tusb_control_request_t request =
-  {
-    .bmRequestType_bit = { .recipient = TUSB_REQ_RCPT_INTERFACE, .type = TUSB_REQ_TYPE_CLASS, .direction = TUSB_DIR_OUT },
-    .bRequest = CDC_REQUEST_SET_CONTROL_LINE_STATE,
-    .wValue = 0x03, // dtr on, cst on
-    .wIndex = p_cdc->itf_num,
-    .wLength = 0
-  };
-
-  TU_ASSERT( usbh_control_xfer(dev_addr, &request, NULL) );
+  return true;
+}
 
+bool cdch_set_config(uint8_t dev_addr, uint8_t itf_num)
+{
+  (void) dev_addr; (void) itf_num;
   return true;
 }
 
-void cdch_isr(uint8_t dev_addr, uint8_t ep_addr, xfer_result_t event, uint32_t xferred_bytes)
+bool cdch_xfer_cb(uint8_t dev_addr, uint8_t ep_addr, xfer_result_t event, uint32_t xferred_bytes)
 {
   (void) ep_addr;
   tuh_cdc_xfer_isr( dev_addr, event, 0, xferred_bytes );
+  return true;
 }
 
 void cdch_close(uint8_t dev_addr)
 {
-  cdch_data_t * p_cdc = &cdch_data[dev_addr-1];
+  cdch_data_t * p_cdc = get_itf(dev_addr);
   tu_memclr(p_cdc, sizeof(cdch_data_t));
 }
 
diff --git a/src/class/cdc/cdc_host.h b/src/class/cdc/cdc_host.h
index 306420ce4..0d435138b 100644
--- a/src/class/cdc/cdc_host.h
+++ b/src/class/cdc/cdc_host.h
@@ -27,8 +27,6 @@
 #ifndef _TUSB_CDC_HOST_H_
 #define _TUSB_CDC_HOST_H_
 
-#include "common/tusb_common.h"
-#include "host/usbh.h"
 #include "cdc.h"
 
 #ifdef __cplusplus
@@ -44,6 +42,18 @@
  * \defgroup   CDC_Serial_Host Host
  * @{ */
 
+bool tuh_cdc_set_control_line_state(uint8_t dev_addr, bool dtr, bool rts, tuh_control_complete_cb_t complete_cb);
+
+static inline bool tuh_cdc_connect(uint8_t dev_addr, tuh_control_complete_cb_t complete_cb)
+{
+  return tuh_cdc_set_control_line_state(dev_addr, true, true, complete_cb);
+}
+
+static inline bool tuh_cdc_disconnect(uint8_t dev_addr, tuh_control_complete_cb_t complete_cb)
+{
+  return tuh_cdc_set_control_line_state(dev_addr, false, false, complete_cb);
+}
+
 /** \brief 			Check if device support CDC Serial interface or not
  * \param[in]		dev_addr	device address
  * \retval      true if device supports
@@ -111,10 +121,11 @@ void tuh_cdc_xfer_isr(uint8_t dev_addr, xfer_result_t event, cdc_pipeid_t pipe_i
 //--------------------------------------------------------------------+
 // Internal Class Driver API
 //--------------------------------------------------------------------+
-void cdch_init(void);
-bool cdch_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *itf_desc, uint16_t *p_length);
-void cdch_isr(uint8_t dev_addr, uint8_t ep_addr, xfer_result_t event, uint32_t xferred_bytes);
-void cdch_close(uint8_t dev_addr);
+void cdch_init       (void);
+bool cdch_open       (uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *itf_desc, uint16_t max_len);
+bool cdch_set_config (uint8_t dev_addr, uint8_t itf_num);
+bool cdch_xfer_cb    (uint8_t dev_addr, uint8_t ep_addr, xfer_result_t event, uint32_t xferred_bytes);
+void cdch_close      (uint8_t dev_addr);
 
 #ifdef __cplusplus
  }
diff --git a/src/class/cdc/cdc_rndis_host.c b/src/class/cdc/cdc_rndis_host.c
index 767b917a1..42b9993bc 100644
--- a/src/class/cdc/cdc_rndis_host.c
+++ b/src/class/cdc/cdc_rndis_host.c
@@ -239,7 +239,7 @@ static tusb_error_t send_message_get_response_subtask( uint8_t dev_addr, cdch_da
   if ( TUSB_ERROR_NONE != error )   STASK_RETURN(error);
 
   //------------- waiting for Response Available notification -------------//
-  (void) hcd_pipe_xfer(p_cdc->pipe_notification, msg_notification[dev_addr-1], 8, true);
+  (void) usbh_edpt_xfer(p_cdc->pipe_notification, msg_notification[dev_addr-1], 8);
   osal_semaphore_wait(rndish_data[dev_addr-1].sem_notification_hdl, OSAL_TIMEOUT_NORMAL, &error);
   if ( TUSB_ERROR_NONE != error )   STASK_RETURN(error);
   STASK_ASSERT(msg_notification[dev_addr-1][0] == 1);