text: /**
   * @section License
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2017, Thomas Barth, barth-dev.de
   *               2018, Michael Wagner, mw@iot-make.de
   * 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.
   */
  
  #ifndef __DRIVERS_CAN_H__
  #define __DRIVERS_CAN_H__
  
  #include <stdint.h>
  #include "CAN_config.h"
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /**
   * \brief CAN frame type (standard/extended)
   */
  typedef enum {
  	CAN_frame_std = 0, /**< Standard frame, using 11 bit identifer. */
  	CAN_frame_ext = 1  /**< Extended frame, using 29 bit identifer. */
  } CAN_frame_format_t;
  
  /**
   * \brief CAN RTR
   */
  typedef enum {
  	CAN_no_RTR = 0, /**< No RTR frame. */
  	CAN_RTR = 1     /**< RTR frame. */
  } CAN_RTR_t;
  
  /** \brief Frame information record type */
  typedef union {
  	uint32_t U; /**< \brief Unsigned access */
  	struct {
  		uint8_t DLC : 4;               /**< \brief [3:0] DLC, Data length container */
  		unsigned int unknown_2 : 2;    /**< \brief \internal unknown */
  		CAN_RTR_t RTR : 1;             /**< \brief [6:6] RTR, Remote Transmission Request */
  		CAN_frame_format_t FF : 1;     /**< \brief [7:7] Frame Format, see# CAN_frame_format_t*/
  		unsigned int reserved_24 : 24; /**< \brief \internal Reserved */
  	} B;
  } CAN_FIR_t;
  
  /** \brief CAN Frame structure */
  typedef struct {
  	CAN_FIR_t FIR;  /**< \brief Frame information record*/
  	uint32_t MsgID; /**< \brief Message ID */
  	union {
  		uint8_t u8[8];   /**< \brief Payload byte access*/
  		uint32_t u32[2]; /**< \brief Payload u32 access*/
  	} data;
  } CAN_frame_t;
  
  typedef enum {
  	Dual_Mode=0, 							/**< \brief The dual acceptance filter option is enabled (two filters, each with the length of 16 bit are active) */
  	Single_Mode=1 							/**< \brief The single acceptance filter option is enabled (one filter with the length of 32 bit is active) */
  } CAN_filter_mode_t;
  
  /** \brief CAN Filter structure */
  typedef struct {
      CAN_filter_mode_t 	FM:1;          		/**< \brief [0:0] Filter Mode */
      uint8_t 			ACR0;				/**< \brief Acceptance Code Register ACR0 */
  	uint8_t 			ACR1;				/**< \brief Acceptance Code Register ACR1 */
  	uint8_t 			ACR2;				/**< \brief Acceptance Code Register ACR2 */
  	uint8_t 			ACR3;				/**< \brief Acceptance Code Register ACR3 */
  	uint8_t 			AMR0;				/**< \brief Acceptance Mask Register AMR0 */
  	uint8_t 			AMR1;				/**< \brief Acceptance Mask Register AMR1 */
  	uint8_t 			AMR2;				/**< \brief Acceptance Mask Register AMR2 */
  	uint8_t 			AMR3;				/**< \brief Acceptance Mask Register AMR3 */
  } CAN_filter_t;
  
  /**
   * \brief Initialize the CAN Module
   *
   * \return 0 CAN Module had been initialized
   */
  int CAN_init(void);
  
  /**
   * \brief Send a can frame
   *
   * \param	p_frame	Pointer to the frame to be send, see #CAN_frame_t
   * \return  0 Frame has been written to the module
   */
  int CAN_write_frame(const CAN_frame_t *p_frame);
  
  /**
   * \brief Stops the CAN Module
   *
   * \return 0 CAN Module was stopped
   */
  int CAN_stop(void);
  
  /**
   * \brief Config CAN Filter, must call before CANInit()
   *
   * \param	p_filter Pointer to the filter, see #CAN_filter_t
   * \return  0 CAN Filter had been initialized
   */
  int CAN_config_filter(const CAN_filter_t* p_filter);
  
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif
  