/************************************************************************************//**
* \file         Source\com.c
* \brief        Bootloader communication interface source file.
* \ingroup      Core
* \internal
*----------------------------------------------------------------------------------------
*                          C O P Y R I G H T
*----------------------------------------------------------------------------------------
*   Copyright (c) 2011  by Feaser    http://www.feaser.com    All rights reserved
*
*----------------------------------------------------------------------------------------
*                            L I C E N S E
*----------------------------------------------------------------------------------------
* This file is part of OpenBLT. OpenBLT is free software: you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* OpenBLT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with OpenBLT.
* If not, see <http://www.gnu.org/licenses/>.
*
* A special exception to the GPL is included to allow you to distribute a combined work 
* that includes OpenBLT without being obliged to provide the source code for any 
* proprietary components. The exception text is included at the bottom of the license
* file <license.html>.
* 
* \endinternal
****************************************************************************************/

/****************************************************************************************
* Include files
****************************************************************************************/
#include "boot.h"                                /* bootloader generic header          */
#if (BOOT_COM_CAN_ENABLE > 0)
  #include "can.h"                                    /* can driver module             */
#endif
#if (BOOT_COM_UART_ENABLE > 0)
  #include "uart.h"                                   /* uart driver module            */
#endif
#if (BOOT_COM_USB_ENABLE > 0)
  #include "usb.h"                                    /* usb driver module             */
#endif


#if (BOOT_COM_ENABLE > 0)
/****************************************************************************************
* Local data declarations
****************************************************************************************/
/**
 * \brief   This variable holds state information about the bootloader being started 
 *          by a reset event or by an activation from a running user program. 
 * \details In case the bootloader is started from a running user progam, the COM 
 *          interface should proceed after initialization as if it already received a 
 *          connection request, which the running user program did before it activated
 *          the bootloader. It's volatile because some targets might call functions that
 *          access this variable from assembly, which might cause the C compiler to 
 *          incorrectly remove this variable during an optimization step.
 *
 *          After a normal reset event, variable comEntryStateConnect must be set to 
 *          BLT_FALSE right before function main() is called. After an entry from the 
 *          user program, the variable must be set to BLT_TRUE right before function 
 *          main() is called. There are typically two methods to correctly implement 
 *          this functionality:
 * 
 *          -# Initialize comEntryStateConnect to BLT_FALSE upon declaration. After a
 *             regular reset, the C-startup will then set it when initializing the 
 *             .data and .bss sections. When the bootloader is re-entered from the user
 *             program, function ComSetConnectEntryState() must be called AFTER the
 *            .data and .bss sections are initialized, but BEFORE function main is 
 *            called.
 *          -# Don't give comEntryStateConnect an initialize value and add a compiler 
 *             specific keyword that results in this variable being skipped during the
 *             .data and .bss section initialization. In this case function 
 *             ComSetDisconnectEntryState() must be called before main() when starting
 *             from a regular reset. When re-entering from the user program, function 
 *             ComSetConnectEntryState() must be called before main().
 *    
 *          The compiler specific keyword for method 2 can be defined through 
 *          preprocessor macro BOOT_CPU_CONNECT_STATE_PREFIX or
 *          BOOT_CPU_CONNECT_STATE_POSTFIX.
 */
#if defined (BOOT_CPU_CONNECT_STATE_PREFIX)
BOOT_CPU_CONNECT_STATE_PREFIX static volatile blt_bool comEntryStateConnect;
#elif defined (BOOT_CPU_CONNECT_STATE_POSTFIX)
static volatile blt_bool comEntryStateConnect BOOT_CPU_CONNECT_STATE_POSTFIX;
#else
static volatile blt_bool comEntryStateConnect = BLT_FALSE;
#endif


/************************************************************************************//**
** \brief     Initializes the communication module including the hardware needed for 
**            the communication.
** \return    none
**
****************************************************************************************/
void ComInit(void)
{
  blt_int8u xcpCtoConnectCmdPacket[2] = { 0xff, 0x00 };

  /* initialize the XCP communication protocol */
  XcpInit();
#if (BOOT_COM_CAN_ENABLE > 0)
  /* initialize the CAN controller */
  CanInit();
#endif
#if (BOOT_COM_UART_ENABLE > 0)
  /* initialize the UART interface */
  UartInit();
#endif
#if (BOOT_COM_USB_ENABLE > 0)
  /* initialize the USB interface */
  UsbInit();
#endif
  /* simulate the reception of a CONNECT command if requested */
  if (comEntryStateConnect == BLT_TRUE)
  {
    XcpPacketReceived(&xcpCtoConnectCmdPacket[0]);
  }
} /*** end of ComInit ***/


/************************************************************************************//**
** \brief     Updates the communication module by checking if new data was received 
**            and submitting the request to process newly received data.
** \return    none
**
****************************************************************************************/
void ComTask(void)
{
  /* make xcpCtoReqPacket static for runtime efficiency */
#if (BOOT_COM_CAN_ENABLE > 0)
  static unsigned char xcpCtoReqPacket[BOOT_COM_CAN_RX_MAX_DATA];
#endif
#if (BOOT_COM_UART_ENABLE > 0)
  static unsigned char xcpCtoReqPacket[BOOT_COM_UART_RX_MAX_DATA];
#endif
#if (BOOT_COM_USB_ENABLE > 0)
  static unsigned char xcpCtoReqPacket[BOOT_COM_USB_RX_MAX_DATA];
#endif
 
#if (BOOT_COM_CAN_ENABLE > 0)
  if (CanReceivePacket(&xcpCtoReqPacket[0]) == BLT_TRUE)
  {
    /* process packet */
    XcpPacketReceived(&xcpCtoReqPacket[0]);
  }
#endif
#if (BOOT_COM_UART_ENABLE > 0)
  if (UartReceivePacket(&xcpCtoReqPacket[0]) == BLT_TRUE)
  {
    /* process packet */
    XcpPacketReceived(&xcpCtoReqPacket[0]);
  }
#endif
#if (BOOT_COM_USB_ENABLE > 0)
  if (UsbReceivePacket(&xcpCtoReqPacket[0]) == BLT_TRUE)
  {
    /* process packet */
    XcpPacketReceived(&xcpCtoReqPacket[0]);
  }
#endif
} /*** end of ComTask ***/


/************************************************************************************//**
** \brief     Releases the communication module.
** \return    none
**
****************************************************************************************/
void ComFree(void)
{
#if (BOOT_COM_USB_ENABLE > 0)
  /* disconnect the usb device from the usb host */
  UsbFree();
#endif
} /*** end of ComFree ***/


/************************************************************************************//**
** \brief     Transmits the packet using the xcp transport layer.
** \param     data Pointer to the byte buffer with packet data.
** \param     len  Number of data bytes that need to be transmitted.
** \return    none
**
****************************************************************************************/
void ComTransmitPacket(blt_int8u *data, blt_int16u len)
{
#if (BOOT_COM_CAN_ENABLE > 0)
  /* transmit the packet. note that len is limited to 8 in the plausibility check,
   * so cast is okay.
   */
  CanTransmitPacket(data, (blt_int8u)len);
#endif
#if (BOOT_COM_UART_ENABLE > 0)
  /* transmit the packet. note that len is limited to 255 in the plausibility check,
   * so cast is okay.
   */
  UartTransmitPacket(data, (blt_int8u)len);
#endif
#if (BOOT_COM_USB_ENABLE > 0)
  /* transmit the packet */
  UsbTransmitPacket(data, len);
#endif

  /* send signal that the packet was transmitted */
  XcpPacketTransmitted();
} /*** end of ComTransmitPacket ***/


/************************************************************************************//**
** \brief     This function should be called by the function that is called to 
**            enter the bootloader from a running user program after the stack 
**            pointer, data section and bss section are initialized, but before 
**            function main is called. It stores state information that indicates 
**            that the COM module must be initialized in a connected state.
** \return    none
**
****************************************************************************************/
void ComSetConnectEntryState(void)
{
  comEntryStateConnect = BLT_TRUE;
} /*** end of ComSetConnectEntryState ***/


/************************************************************************************//**
** \brief     This function should be called by the reset handler after the stack 
**            pointer, data section and bss section are initialized, but before 
**            function main is called. It stores state information that indicates 
**            that the COM module must be initialized in a disconnected state.
** \return    none
**
****************************************************************************************/
void ComSetDisconnectEntryState(void)
{
  comEntryStateConnect = BLT_FALSE;
} /*** end of ComSetDisconnectEntryState ***/


/************************************************************************************//**
** \brief     This function checks if there is a pending request for a connection 
**            upon COM module initialization.
** \return    BLT_TRUE is there is a pending connection request, BLT_FALSE otherwise.
**
****************************************************************************************/
blt_bool ComIsConnectEntryState(void)
{
  return comEntryStateConnect;
} /*** end of ComIsConnectEntryState ***/


/************************************************************************************//**
** \brief     This function obtains the XCP connection state.
** \return    BLT_TRUE when an XCP connection is established, BLT_FALSE otherwise.
**
****************************************************************************************/
blt_bool ComIsConnected(void)
{
  return XcpIsConnected();
} /*** end of ComIsConnected ***/

#else
/************************************************************************************//**
** \brief     This function should be called by the function that is called to 
**            enter the bootloader from a running user program after the stack 
**            pointer, data section and bss section are initialized, but before 
**            function main is called. It stores state information that indicates 
**            that the COM module must be initialized in a connected state.
** \return    none
**
****************************************************************************************/
void ComSetConnectEntryState(void)
{
  /* empty placeholder function because this one is called from the c-startup. on some
   * targets, this one is written in assembly that doesn't support precompiler 
   * statements
   */
} /*** end of ComSetConnectEntryState ***/


/************************************************************************************//**
** \brief     This function should be called by the reset handler after the stack 
**            pointer, data section and bss section are initialized, but before 
**            function main is called. It stores state information that indicates 
**            that the COM module must be initialized in a disconnected state.
** \return    none
**
****************************************************************************************/
void ComSetDisconnectEntryState(void)
{
  /* empty placeholder function because this one is called from the c-startup. on some
   * targets, this one is written in assembly that doesn't support precompiler 
   * statements
   */
} /*** end of ComSetDisconnectEntryState ***/

#endif /* BOOT_COM_ENABLE > 0 */

/*********************************** end of com.c **************************************/