circuitpython/stm/stmusbd/usbd_cdc_vcp.c

/**
  ******************************************************************************
  * @file    usbd_cdc_vcp.c
  * @author  MCD Application Team
  * @version V1.1.0
  * @date    19-March-2012
  * @brief   Generic media access Layer.
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; COPYRIGHT 2012 STMicroelectronics</center></h2>
  *
  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
  * You may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *        http://www.st.com/software_license_agreement_liberty_v2
  *
  * Unless required by applicable law or agreed to in writing, software 
  * distributed under the License is distributed on an "AS IS" BASIS, 
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  ******************************************************************************
  */ 

#ifdef USB_OTG_HS_INTERNAL_DMA_ENABLED 
#pragma     data_alignment = 4 
#endif /* USB_OTG_HS_INTERNAL_DMA_ENABLED */

/* Includes ------------------------------------------------------------------*/
#include "usbd_conf.h"
#include "usbd_cdc_vcp.h"

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
LINE_CODING linecoding =
  {
    115200, /* baud rate*/
    0x00,   /* stop bits-1*/
    0x00,   /* parity - none*/
    0x08    /* nb. of bits 8*/
  };


/* These are external variables imported from CDC core to be used for IN 
   transfer management. */

extern uint32_t APP_dev_is_connected; // set if CDC device is connected

extern uint8_t  APP_Rx_Buffer []; /* Write CDC received data in this buffer.
                                     These data will be sent over USB IN endpoint
                                     in the CDC core functions. */
extern uint32_t APP_Rx_ptr_in;    /* Increment this pointer or roll it back to
                                     start address when writing received data
                                     in the buffer APP_Rx_Buffer. */

/* Private function prototypes -----------------------------------------------*/
static uint16_t VCP_Init     (void);
static uint16_t VCP_DeInit   (void);
static uint16_t VCP_Ctrl     (uint32_t Cmd, uint8_t* Buf, uint32_t Len);
static uint16_t VCP_DataTx   (const uint8_t* Buf, uint32_t Len);
static uint16_t VCP_DataRx   (uint8_t* Buf, uint32_t Len);

CDC_IF_Prop_TypeDef VCP_fops = 
{
  VCP_Init,
  VCP_DeInit,
  VCP_Ctrl,
  VCP_DataTx,
  VCP_DataRx
};

/* Private functions ---------------------------------------------------------*/
/**
  * @brief  VCP_Init
  *         Initializes the Media on the STM32
  * @param  None
  * @retval Result of the opeartion (USBD_OK in all cases)
  */
static uint16_t VCP_Init(void) {
    return USBD_OK;
}

/**
  * @brief  VCP_DeInit
  *         DeInitializes the Media on the STM32
  * @param  None
  * @retval Result of the opeartion (USBD_OK in all cases)
  */
static uint16_t VCP_DeInit(void)
{

  return USBD_OK;
}


/**
  * @brief  VCP_Ctrl
  *         Manage the CDC class requests
  * @param  Cmd: Command code            
  * @param  Buf: Buffer containing command data (request parameters)
  * @param  Len: Number of data to be sent (in bytes)
  * @retval Result of the opeartion (USBD_OK in all cases)
  */
static uint16_t VCP_Ctrl (uint32_t Cmd, uint8_t* Buf, uint32_t Len)
{ 
  switch (Cmd)
  {
  case SEND_ENCAPSULATED_COMMAND:
    /* Not  needed for this driver */
    break;

  case GET_ENCAPSULATED_RESPONSE:
    /* Not  needed for this driver */
    break;

  case SET_COMM_FEATURE:
    /* Not  needed for this driver */
    break;

  case GET_COMM_FEATURE:
    /* Not  needed for this driver */
    break;

  case CLEAR_COMM_FEATURE:
    /* Not  needed for this driver */
    break;

  case SET_LINE_CODING:
    /*
    linecoding.bitrate = (uint32_t)(Buf[0] | (Buf[1] << 8) | (Buf[2] << 16) | (Buf[3] << 24));
    linecoding.format = Buf[4];
    linecoding.paritytype = Buf[5];
    linecoding.datatype = Buf[6];
    // Set the new configuration
    VCP_COMConfig(OTHER_CONFIG);
    */
    break;

  case GET_LINE_CODING:
    /*
    Buf[0] = (uint8_t)(linecoding.bitrate);
    Buf[1] = (uint8_t)(linecoding.bitrate >> 8);
    Buf[2] = (uint8_t)(linecoding.bitrate >> 16);
    Buf[3] = (uint8_t)(linecoding.bitrate >> 24);
    Buf[4] = linecoding.format;
    Buf[5] = linecoding.paritytype;
    Buf[6] = linecoding.datatype; 
    */
    Buf[0] = 0;
    Buf[1] = 0;
    Buf[2] = 0;
    Buf[3] = 0;
    Buf[4] = 0;
    Buf[5] = 0;
    Buf[6] = 0;
    break;

  case SET_CONTROL_LINE_STATE:
    APP_dev_is_connected = Len & 0x1; // wValue is passed in Len (bit of a hack)
    break;

  case SEND_BREAK:
    /* Not  needed for this driver */
    break;    
    
  default:
    break;
  }

  return USBD_OK;
}

/**
  * @brief  VCP_DataTx
  *         CDC received data to be send over USB IN endpoint are managed in 
  *         this function.
  * @param  Buf: Buffer of data to be sent
  * @param  Len: Number of data to be sent (in bytes)
  * @retval Result of the opeartion: USBD_OK if all operations are OK else VCP_FAIL
  */
static uint16_t VCP_DataTx (const uint8_t* Buf, uint32_t Len)
{
    for (int i = 0; i < Len; i++) {
        APP_Rx_Buffer[APP_Rx_ptr_in] = Buf[i];
        APP_Rx_ptr_in++;

        /* To avoid buffer overflow */
        if(APP_Rx_ptr_in == APP_RX_DATA_SIZE) {
            APP_Rx_ptr_in = 0;
        }
    }

    return USBD_OK;
}

/**
  * @brief  VCP_DataRx
  *         Data received over USB OUT endpoint are sent over CDC interface 
  *         through this function.
  *           
  *         @note
  *         This function will block any OUT packet reception on USB endpoint 
  *         untill exiting this function. If you exit this function before transfer
  *         is complete on CDC interface (ie. using DMA controller) it will result 
  *         in receiving more data while previous ones are still not sent.
  *                 
  * @param  Buf: Buffer of data to be received
  * @param  Len: Number of data received (in bytes)
  * @retval Result of the opeartion: USBD_OK if all operations are OK else VCP_FAIL
  */
static uint16_t VCP_DataRx (uint8_t* Buf, uint32_t Len) {
    extern void usb_vcp_receive(uint8_t *buf, uint32_t len);
    usb_vcp_receive(Buf, Len);
    return USBD_OK;
}

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/