lin_api.c

针对日本瑞莎单片机r8c/23 开发的LIN网络通讯程序包括主节点和从节点

/******************************************************************************/
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/*  Copyright (c) 2003, 2004, 2005 and 2006 Renesas Technology America, Inc.  */
/******************************************************************************/
/**********************************************************************
   Title                      : lin_api.c

   Module Description         : This file contains the LIN 2.0 API function routines.

   MCU Family                 : R8C

   Author                     : Bob Chamberlain

   Version                    : LIN API 2.0 Version 1.1

 *********************************************************************/

/**********************************************************************
 * Include header files
 *********************************************************************/
#include "lin_api.h"

/*********************************************************************
 * File level pragmas
 *********************************************************************/

/**********************************************************************
 * Constant and Macro Definitions using #define
 *********************************************************************/

/**********************************************************************
 * Enumerations, Structures and Typedefs
 *********************************************************************/

/**********************************************************************
 * Global and Const Variable Defining Definitions / Initializations
 *********************************************************************/

/**********************************************************************
 * Static Variables With File Level Scope
 *********************************************************************/

/**********************************************************************
 * ROM Const Variables With File Level Scope
 *********************************************************************/

/**********************************************************************
 * Function Prototypes for Private Functions with File Level Scope
 *********************************************************************/

/**********************************************************************
 * Function Definitions
 *********************************************************************/

/**********************************************************************
 *    Function Name: l_sys_irq_disable()
 *      Description: Disables all interrupts.
 *       Parameters: None.
 *          Returns: Interrupt enable flag state prior to the call.
 *  Ext. References: None.
 *      Preemptible: Yes.
 *        Reentrant: Yes.
 *********************************************************************/
l_irqmask l_sys_irq_disable(void)
{
   unsigned int rdflg;
   unsigned char flg_state;

   /* Read the current state of the flag register.  */
   _asm("STC FLG,$$[FB]", rdflg);
   _asm("FCLR I");   /* Clear the global interrupt enable flag.  */
   /* Determine if the I flag is set in the flag register.  */
   if ((rdflg & 0x0040) != 0)
   {
      flg_state = 0x01;
   }
   else
   {
      flg_state = 0x00;
   }
   return (flg_state); /* Return prior state of the interrupt mask bit.  */
}

/**********************************************************************
 *    Function Name: l_sys_irq_restore()
 *      Description: Restores a value to the interrupt mask bit.
 *       Parameters: flag_state - flag value to restore.
 *          Returns: Nothing.
 *  Ext. References: None.
 *      Preemptible: Yes.
 *        Reentrant: Yes.
 *********************************************************************/
void l_sys_irq_restore(l_irqmask flag_state)
{
   if (flag_state)
   {
      _asm("FSET I"); /* Set the global interrupt enable flag.  */
   }
   else
   {
      _asm("FCLR I"); /* Clear the global interrupt enable flag.  */
   }
   return;
}

/**********************************************************************
 *    Function Name: l_sys_init()
 *      Description: Initializes the I/O pins used by the LIN system
 *                   resources.
 *       Parameters: None.
 *          Returns: Always returns 0.
 *  Ext. References: None.
 *      Preemptible: Yes.
 *        Reentrant: Yes.
 *
 *********************************************************************/
l_bool l_sys_init(void)
{
   /* Set up the I/O pins used by the LIN interface.  */
   LIN_CONTROL_REG = 0x00;    /* Take the interface out of LIN mode for the moment.  */
   LIN_PORT_RXD_DIR;          /* Make sure the UART RXD pin is an input.  */
   LIN_PORT_DATA_OUT = 1;          /* Set the TXD port latch to 1 (inactive LIN Bus level).  */
   LIN_PORT_TXD_DIR;          /* Configure the TXD port to output (when in I/O mode).  */
   LIN_UART_MODE_REG = 0x00;  /* Clear UART mode to place RxD and TxD into I/O mode.  */
   #ifdef LIN_XCVR_ENABLE
      LIN_TXCVR_ENABLE;          /* Set the LIN transceiver enable port to enabled state.  */
      LIN_TXCVR_ENABLE_DIR;      /* Set the LIN transceiver enable port to output.  */
   #endif
   #ifdef LIN_CORE_TIME_ENABLE
      LIN_CORE_TIME = 0;         /* Set the time measurement pin to 0 (off).  */
      LIN_CORE_TIME_DIR;         /* Set the time measurement pin to an output.  */
   #endif
   return (0);
}

/**********************************************************************
 *    Function Name: l_ifc_init()
 *      Description: Initializes the LIN interface hardware resources.
 *       Parameters: ifc_name - index number of the LIN interface - only
 *                   0 is allowed.
 *          Returns: Nothing.
 *  Ext. References: LIN_TX_END_FLG, LIN_RX_END_FLG.
 *      Preemptible: No.
 *        Reentrant: No.
 *
 * Note: This routine assumes that each node implements a single LIN
 * interface, defined as interface 0 in "lin_dev.h" (the value of "LIN"
 * is set to 0 by default).  The API software should be modified to
 * allow multiple LIN interfaces to be implemented.
 *********************************************************************/
void l_ifc_init(l_ifc_handle ifc_name)
{
   /* Do nothing if the specified interface is not interface 0.  */
   if (ifc_name == LIN)
   {
      #if (LIN_MASTER_NODE == LIN_MY_NODE_NAME)
         lin_init_schedule_timer();                /* Configure the LIN schedule and break timers.  */
         LIN_now_schedule = LIN_L_NULL_SCHEDULE;   /* Set the schedule table to the "empty" table.  */
      #else
         lin_init_timer();                   /* Configure the LIN break timer.  */
      #endif
      lin_init_serial_if();                  /* Configure the LIN serial interface.  */
      /* Initialize the system API flags.  LIN_AWAKE_FLG is cleared in "lin_change_node_status()".  */
      API_TX_END_FLG = 0;  /* Initialize LIN_TX_END_FLG.  */
      API_RX_END_FLG = 0;  /* Initialize LIN_RX_END_FLG.  */
      lin_change_node_status(DISCONNECT);    /* Place the node in the "disconnect" state so it cannot be used.  */
      lin_change_bus_status(QUIET_STATE);    /* Set the LIN bus state to inactive.  */
   }
}

/**********************************************************************
 *    Function Name: l_ifc_connect()
 *      Description: Places the LIN interface in the "connect" state for use.
 *       Parameters: ifc_name - index number of the LIN interface - only
 *                   0 is allowed.
 *          Returns: Always 0.
 *  Ext. References: No direct external references.
 *      Preemptible: No.
 *        Reentrant: No.
 *
 * Note: This routine assumes that each node implements a single LIN
 * interface, defined as interface 0 in "lin_dev.h" (the value of "LIN"
 * is set to 0 by default).  The API software should be modified to
 * allow multiple LIN interfaces to be implemented.
 *********************************************************************/
l_bool l_ifc_connect(l_ifc_handle ifc_name)
{
   /* Do nothing if the specified interface is not interface 0.  */
   if (ifc_name == LIN)
   {
      lin_change_node_status(CONNECT);       /* Place the node in the "connect" state so it can be used.  */
      lin_change_bus_status(QUIET_STATE);    /* Set the LIN bus state to inactive.  */
   }
   return (0);    /* Always returns 0 (success), which is OK as long as no errors can occur.  */
}

/**********************************************************************
 *    Function Name: l_ifc_disconnect()
 *      Description: Returns the LIN interface to the idle state after use.
 *       Parameters: ifc_name - index number of the LIN interface - only
 *                   0 is allowed.
 *          Returns: Always 0.
 *  Ext. References: No direct external references.
 *      Preemptible: No.
 *        Reentrant: No.
 *
 * Note: This routine assumes that each node implements a single LIN
 * interface, defined as interface 0 in "lin_dev.h" (the value of "LIN"
 * is set to 0 by default).  The API software should be modified to
 * allow multiple LIN interfaces to be implemented.
 *********************************************************************/
l_bool l_ifc_disconnect(l_ifc_handle ifc_name)
{
   /* Do nothing if the specified interface is not interface 0.  */
   if (ifc_name == LIN)
   {
      /* Wait for the LIN bus to enter the quiet state (between LIN frames).  */
      while (LIN_bus_status != QUIET_STATE);
      lin_change_node_status(DISCONNECT);    /* Place the node in the "disconnect" state so it cannot be used.  */
   }
   return (0);    /* Always returns 0 (success), which is OK as long as no errors can occur.  */
}

/**********************************************************************
 *    Function Name: l_flg_tst()
 *      Description: Reads a system flag or signal status byte.
 *       Parameters: flg - possible values:
 *                      any valid signal name defined in "lin_dev.h"
 *                      LIN_TX_END_FLG (253)
 *                      LIN_RX_END_FLG (254)
 *                      LIN_AWAKE_FLG (254)
 *                      LIN_DIAG_RESP_FLG (255).
 *          Returns: Boolean 1 if the requested flag or status byte is not 0.
 *  Ext. References: LIN_sleep_timer, system flag referenced by "flg".
 *      Preemptible: Yes.
 *        Reentrant: No.
 *********************************************************************/
l_bool l_flg_tst(l_flag_handle flg)
{
   unsigned char flag_state;
   unsigned char ret_val;

   #if ((LIN_MASTER_NODE != LIN_MY_NODE_NAME) && (defined USE_POWER_CONTROL))
      /* If this is a Slave node, put the node in the sleep state if "LIN_sleep_timer"
       * is greater than 4.  */
      if (LIN_sleep_timer > 4)
      {
         LIN_sleep_timer = 0;
         flag_state = l_sys_irq_disable();   /* Disable the global interrupt.  */
         lin_change_node_status(SLEEP_STATE);
         l_sys_irq_restore(flag_state);      /* Restore the global interrupt.  */
      }
   #endif   /* Slave node and USE_POWER_CONTROL is defined.  */
   /* If "flg" has the value 252, 253, 254 or 255, this request is for one of the
    * API flags LIN TX_END_FLG, LIN_END_FLG, LIN_AWAKE_FLG or LIN_DIAG_RESP_FLG.
    * Otherwise, the request is for the status of one of the user signals defined
    * in "LIN_signal_table[]".  */
   if (flg > 251)
   {