merge with current master

1 files changed, 424 insertions, 415 deletions

diff --git a/src/class/cdc/cdc_device.c b/src/class/cdc/cdc_device.c
index 015c1c6fd..73eafab07 100644
--- a/src/class/cdc/cdc_device.c
+++ b/src/class/cdc/cdc_device.c
@@ -1,415 +1,424 @@
-/* 

- * The MIT License (MIT)

- *

- * Copyright (c) 2019 Ha Thach (tinyusb.org)

- *

- * Permission is hereby granted, free of charge, to any person obtaining a copy

- * of this software and associated documentation files (the "Software"), to deal

- * in the Software without restriction, including without limitation the rights

- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

- * copies of the Software, and to permit persons to whom the Software is

- * furnished to do so, subject to the following conditions:

- *

- * The above copyright notice and this permission notice shall be included in

- * all copies or substantial portions of the Software.

- *

- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

- * THE SOFTWARE.

- *

- * This file is part of the TinyUSB stack.

- */

-

-#include "tusb_option.h"

-

-#if (TUSB_OPT_DEVICE_ENABLED && CFG_TUD_CDC)

-

-#include "cdc_device.h"

-#include "device/usbd_pvt.h"

-

-//--------------------------------------------------------------------+

-// MACRO CONSTANT TYPEDEF

-//--------------------------------------------------------------------+

-typedef struct

-{

-  uint8_t itf_num;

-  uint8_t ep_notif;

-  uint8_t ep_in;

-  uint8_t ep_out;

-

-  // Bit 0:  DTR (Data Terminal Ready), Bit 1: RTS (Request to Send)

-  uint8_t line_state;

-

-  /*------------- From this point, data is not cleared by bus reset -------------*/

-  char    wanted_char;

-  cdc_line_coding_t line_coding;

-

-  // FIFO

-  tu_fifo_t rx_ff;

-  tu_fifo_t tx_ff;

-

-  uint8_t rx_ff_buf[CFG_TUD_CDC_RX_BUFSIZE];

-  uint8_t tx_ff_buf[CFG_TUD_CDC_TX_BUFSIZE];

-

-#if CFG_FIFO_MUTEX

-  osal_mutex_def_t rx_ff_mutex;

-  osal_mutex_def_t tx_ff_mutex;

-#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];

-

-}cdcd_interface_t;

-

-#define ITF_MEM_RESET_SIZE   offsetof(cdcd_interface_t, wanted_char)

-

-//--------------------------------------------------------------------+

-// INTERNAL OBJECT & FUNCTION DECLARATION

-//--------------------------------------------------------------------+

-CFG_TUSB_MEM_SECTION static cdcd_interface_t _cdcd_itf[CFG_TUD_CDC];

-

-static void _prep_out_transaction (uint8_t itf)

-{

-  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;

-

-  // 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 >= TU_ARRAY_SIZE(p_cdc->epout_buf) )

-  {

-    usbd_edpt_xfer(TUD_OPT_RHPORT, p_cdc->ep_out, p_cdc->epout_buf, TU_ARRAY_SIZE(p_cdc->epout_buf));

-  }

-}

-

-//--------------------------------------------------------------------+

-// APPLICATION API

-//--------------------------------------------------------------------+

-bool tud_cdc_n_connected(uint8_t itf)

-{

-  // DTR (bit 0) active  is considered as connected

-  return tud_ready() && tu_bit_test(_cdcd_itf[itf].line_state, 0);

-}

-

-uint8_t tud_cdc_n_get_line_state (uint8_t itf)

-{

-  return _cdcd_itf[itf].line_state;

-}

-

-void tud_cdc_n_get_line_coding (uint8_t itf, cdc_line_coding_t* coding)

-{

-  (*coding) = _cdcd_itf[itf].line_coding;

-}

-

-void tud_cdc_n_set_wanted_char (uint8_t itf, char wanted)

-{

-  _cdcd_itf[itf].wanted_char = wanted;

-}

-

-

-//--------------------------------------------------------------------+

-// READ API

-//--------------------------------------------------------------------+

-uint32_t tud_cdc_n_available(uint8_t itf)

-{

-  return tu_fifo_count(&_cdcd_itf[itf].rx_ff);

-}

-

-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);

-  return num_read;

-}

-

-bool tud_cdc_n_peek(uint8_t itf, int pos, uint8_t* chr)

-{

-  return tu_fifo_peek_at(&_cdcd_itf[itf].rx_ff, pos, chr);

-}

-

-void tud_cdc_n_read_flush (uint8_t itf)

-{

-  tu_fifo_clear(&_cdcd_itf[itf].rx_ff);

-  _prep_out_transaction(itf);

-}

-

-//--------------------------------------------------------------------+

-// WRITE API

-//--------------------------------------------------------------------+

-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);

-

-#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 )

-  {

-    tud_cdc_n_write_flush(itf);

-  }

-#endif

-

-  return ret;

-}

-

-bool 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, TU_ARRAY_SIZE(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) );

-  }

-

-  return true;

-}

-

-uint32_t tud_cdc_n_write_available (uint8_t itf)

-{

-  return tu_fifo_remaining(&_cdcd_itf[itf].tx_ff);

-}

-

-

-//--------------------------------------------------------------------+

-// USBD Driver API

-//--------------------------------------------------------------------+

-void cdcd_init(void)

-{

-  tu_memclr(_cdcd_itf, sizeof(_cdcd_itf));

-

-  for(uint8_t i=0; i<CFG_TUD_CDC; i++)

-  {

-    cdcd_interface_t* p_cdc = &_cdcd_itf[i];

-

-    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.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, TU_ARRAY_SIZE(p_cdc->rx_ff_buf), 1, false);

-    tu_fifo_config(&p_cdc->tx_ff, p_cdc->tx_ff_buf, TU_ARRAY_SIZE(p_cdc->tx_ff_buf), 1, false);

-

-#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));

-#endif

-  }

-}

-

-void cdcd_reset(uint8_t rhport)

-{

-  (void) 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);

-  }

-}

-

-bool cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t *p_length)

-{

-  // 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);

-

-  // Find available interface

-  cdcd_interface_t * p_cdc = NULL;

-  uint8_t cdc_id;

-  for(cdc_id=0; cdc_id<CFG_TUD_CDC; cdc_id++)

-  {

-    if ( _cdcd_itf[cdc_id].ep_in == 0 )

-    {

-      p_cdc = &_cdcd_itf[cdc_id];

-      break;

-    }

-  }

-  TU_ASSERT(p_cdc);

-

-  //------------- Control Interface -------------//

-  p_cdc->itf_num = itf_desc->bInterfaceNumber;

-

-  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) )

-  {

-    (*p_length) += 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) );

-

-    p_cdc->ep_notif = ((tusb_desc_endpoint_t const *) p_desc)->bEndpointAddress;

-

-    (*p_length) += p_desc[DESC_OFFSET_LEN];

-    p_desc = tu_desc_next(p_desc);

-  }

-

-  //------------- Data Interface (if any) -------------//

-  if ( (TUSB_DESC_INTERFACE == p_desc[DESC_OFFSET_TYPE]) &&

-       (TUSB_CLASS_CDC_DATA == ((tusb_desc_interface_t const *) p_desc)->bInterfaceClass) )

-  {

-    // next to endpoint descriptor

-    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) );

-

-    (*p_length) += sizeof(tusb_desc_interface_t) + 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;

-  }

-

-  // 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;

-}

-

-// Handle class control request

-// return false to stall control endpoint (e.g unsupported request)

-bool cdcd_control_request(uint8_t rhport, tusb_control_request_t const * request)

-{

-  // Handle class request only

-  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;

-  }

-

-  switch ( request->bRequest )

-  {

-    case CDC_REQUEST_SET_LINE_CODING:

-      tud_control_xfer(rhport, request, &p_cdc->line_coding, sizeof(cdc_line_coding_t));

-    break;

-

-    case CDC_REQUEST_GET_LINE_CODING:

-      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;

-

-      tud_control_status(rhport, request);

-

-      // 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));

-    break;

-

-    default: return false; // stall unsupported request

-  }

-

-  return true;

-}

-

-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;

-

-  // Identify which interface to use

-  for ( ; ; itf++, p_cdc++)

-  {

-    if (itf >= TU_ARRAY_SIZE(_cdcd_itf)) return false;

-

-    if ( ( ep_addr == p_cdc->ep_out ) || ( ep_addr == p_cdc->ep_in ) ) break;

-  }

-

-  // Received new data

-  if ( ep_addr == p_cdc->ep_out )

-  {

-    for(uint32_t i=0; i<xferred_bytes; i++)

-    {

-      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] ) )

-      {

-        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);

-

-    // prepare for OUT transaction

-    _prep_out_transaction(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 ( xferred_bytes && (0 == (xferred_bytes % CFG_TUD_CDC_EPSIZE)) ) usbd_edpt_xfer(TUD_OPT_RHPORT, p_cdc->ep_in, NULL, 0);

-  }

-

-  // nothing to do with notif endpoint for now

-

-  return true;

-}

-

-#endif

+/* 
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#include "tusb_option.h"
+
+#if (TUSB_OPT_DEVICE_ENABLED && CFG_TUD_CDC)
+
+#include "cdc_device.h"
+#include "device/usbd_pvt.h"
+
+//--------------------------------------------------------------------+
+// MACRO CONSTANT TYPEDEF
+//--------------------------------------------------------------------+
+typedef struct
+{
+  uint8_t itf_num;
+  uint8_t ep_notif;
+  uint8_t ep_in;
+  uint8_t ep_out;
+
+  // Bit 0:  DTR (Data Terminal Ready), Bit 1: RTS (Request to Send)
+  uint8_t line_state;
+
+  /*------------- From this point, data is not cleared by bus reset -------------*/
+  char    wanted_char;
+  cdc_line_coding_t line_coding;
+
+  // FIFO
+  tu_fifo_t rx_ff;
+  tu_fifo_t tx_ff;
+
+  uint8_t rx_ff_buf[CFG_TUD_CDC_RX_BUFSIZE];
+  uint8_t tx_ff_buf[CFG_TUD_CDC_TX_BUFSIZE];
+
+#if CFG_FIFO_MUTEX
+  osal_mutex_def_t rx_ff_mutex;
+  osal_mutex_def_t tx_ff_mutex;
+#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];
+
+}cdcd_interface_t;
+
+#define ITF_MEM_RESET_SIZE   offsetof(cdcd_interface_t, wanted_char)
+
+//--------------------------------------------------------------------+
+// INTERNAL OBJECT & FUNCTION DECLARATION
+//--------------------------------------------------------------------+
+CFG_TUSB_MEM_SECTION static cdcd_interface_t _cdcd_itf[CFG_TUD_CDC];
+
+static void _prep_out_transaction (uint8_t itf)
+{
+  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;
+
+  // 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 >= TU_ARRAY_SIZE(p_cdc->epout_buf) )
+  {
+    usbd_edpt_xfer(TUD_OPT_RHPORT, p_cdc->ep_out, p_cdc->epout_buf, TU_ARRAY_SIZE(p_cdc->epout_buf));
+  }
+}
+
+//--------------------------------------------------------------------+
+// APPLICATION API
+//--------------------------------------------------------------------+
+bool tud_cdc_n_connected(uint8_t itf)
+{
+  // DTR (bit 0) active  is considered as connected
+  return tud_ready() && tu_bit_test(_cdcd_itf[itf].line_state, 0);
+}
+
+uint8_t tud_cdc_n_get_line_state (uint8_t itf)
+{
+  return _cdcd_itf[itf].line_state;
+}
+
+void tud_cdc_n_get_line_coding (uint8_t itf, cdc_line_coding_t* coding)
+{
+  (*coding) = _cdcd_itf[itf].line_coding;
+}
+
+void tud_cdc_n_set_wanted_char (uint8_t itf, char wanted)
+{
+  _cdcd_itf[itf].wanted_char = wanted;
+}
+
+
+//--------------------------------------------------------------------+
+// READ API
+//--------------------------------------------------------------------+
+uint32_t tud_cdc_n_available(uint8_t itf)
+{
+  return tu_fifo_count(&_cdcd_itf[itf].rx_ff);
+}
+
+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);
+  return num_read;
+}
+
+bool tud_cdc_n_peek(uint8_t itf, int pos, uint8_t* chr)
+{
+  return tu_fifo_peek_at(&_cdcd_itf[itf].rx_ff, pos, chr);
+}
+
+void tud_cdc_n_read_flush (uint8_t itf)
+{
+  tu_fifo_clear(&_cdcd_itf[itf].rx_ff);
+  _prep_out_transaction(itf);
+}
+
+//--------------------------------------------------------------------+
+// WRITE API
+//--------------------------------------------------------------------+
+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);
+
+#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 )
+  {
+    tud_cdc_n_write_flush(itf);
+  }
+#endif
+
+  return ret;
+}
+
+bool 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, TU_ARRAY_SIZE(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) );
+  }
+
+  return true;
+}
+
+uint32_t tud_cdc_n_write_available (uint8_t itf)
+{
+  return tu_fifo_remaining(&_cdcd_itf[itf].tx_ff);
+}
+
+
+//--------------------------------------------------------------------+
+// USBD Driver API
+//--------------------------------------------------------------------+
+void cdcd_init(void)
+{
+  tu_memclr(_cdcd_itf, sizeof(_cdcd_itf));
+
+  for(uint8_t i=0; i<CFG_TUD_CDC; i++)
+  {
+    cdcd_interface_t* p_cdc = &_cdcd_itf[i];
+
+    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.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, TU_ARRAY_SIZE(p_cdc->rx_ff_buf), 1, false);
+    tu_fifo_config(&p_cdc->tx_ff, p_cdc->tx_ff_buf, TU_ARRAY_SIZE(p_cdc->tx_ff_buf), 1, false);
+
+#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));
+#endif
+  }
+}
+
+void cdcd_reset(uint8_t rhport)
+{
+  (void) 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);
+  }
+}
+
+bool cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t *p_length)
+{
+  // 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);
+
+  // Find available interface
+  cdcd_interface_t * p_cdc = NULL;
+  uint8_t cdc_id;
+  for(cdc_id=0; cdc_id<CFG_TUD_CDC; cdc_id++)
+  {
+    if ( _cdcd_itf[cdc_id].ep_in == 0 )
+    {
+      p_cdc = &_cdcd_itf[cdc_id];
+      break;
+    }
+  }
+  TU_ASSERT(p_cdc);
+
+  //------------- Control Interface -------------//
+  p_cdc->itf_num = itf_desc->bInterfaceNumber;
+
+  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) )
+  {
+    (*p_length) += 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) );
+
+    p_cdc->ep_notif = ((tusb_desc_endpoint_t const *) p_desc)->bEndpointAddress;
+
+    (*p_length) += p_desc[DESC_OFFSET_LEN];
+    p_desc = tu_desc_next(p_desc);
+  }
+
+  //------------- Data Interface (if any) -------------//
+  if ( (TUSB_DESC_INTERFACE == p_desc[DESC_OFFSET_TYPE]) &&
+       (TUSB_CLASS_CDC_DATA == ((tusb_desc_interface_t const *) p_desc)->bInterfaceClass) )
+  {
+    // next to endpoint descriptor
+    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) );
+
+    (*p_length) += sizeof(tusb_desc_interface_t) + 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;
+  }
+
+  // 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;
+}
+
+// Handle class control request
+// return false to stall control endpoint (e.g unsupported request)
+bool cdcd_control_request(uint8_t rhport, tusb_control_request_t const * request)
+{
+  // Handle class request only
+  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;
+  }
+
+  switch ( request->bRequest )
+  {
+    case CDC_REQUEST_SET_LINE_CODING:
+      TU_LOG2("  Set Line Coding\n");
+      tud_control_xfer(rhport, request, &p_cdc->line_coding, sizeof(cdc_line_coding_t));
+    break;
+
+    case CDC_REQUEST_GET_LINE_CODING:
+      TU_LOG2("  Get Line Coding\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)
+      bool const dtr = tu_bit_test(request->wValue, 0);
+      bool const rts = tu_bit_test(request->wValue, 1);
+
+      p_cdc->line_state = (uint8_t) request->wValue;
+
+      TU_LOG2("  Set Control Line State: DTR = %d, RTS = %d\n", dtr, rts);
+
+      tud_control_status(rhport, request);
+
+      // Invoke callback
+      if ( tud_cdc_line_state_cb) tud_cdc_line_state_cb(itf, dtr, rts);
+    }
+    break;
+
+    default: return false; // stall unsupported request
+  }
+
+  return true;
+}
+
+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;
+
+  // Identify which interface to use
+  for ( ; ; itf++, p_cdc++)
+  {
+    if (itf >= TU_ARRAY_SIZE(_cdcd_itf)) return false;
+
+    if ( ( ep_addr == p_cdc->ep_out ) || ( ep_addr == p_cdc->ep_in ) ) break;
+  }
+
+  // Received new data
+  if ( ep_addr == p_cdc->ep_out )
+  {
+    for(uint32_t i=0; i<xferred_bytes; i++)
+    {
+      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] ) )
+      {
+        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);
+
+    // prepare for OUT transaction
+    _prep_out_transaction(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 ( xferred_bytes && (0 == (xferred_bytes % CFG_TUD_CDC_EPSIZE)) ) usbd_edpt_xfer(TUD_OPT_RHPORT, p_cdc->ep_in, NULL, 0);
+  }
+
+  // nothing to do with notif endpoint for now
+
+  return true;
+}
+
+#endif