/*
 * FreeModbus Libary: BARE Port
 * Copyright (C) 2006 Christian Walter <wolti@sil.at>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * File: $Id: porttimer.c,v 1.1 2006/08/22 21:35:13 wolti Exp $
 */

/* ----------------------- Platform includes --------------------------------*/
#include "port.h"

/* ----------------------- Modbus includes ----------------------------------*/
#include "mb.h"
#include "mbport.h"

/* ----------------------- static functions ---------------------------------*/
static void prvvTIMERExpiredISR(void);

/* ----------------------- Start implementation -----------------------------*/

/**
  * @brief  TIM4³õʼ»¯
  * @param  ÎÞ
  * @retval ״̬±êÖ¾
  */
BOOL xMBPortTimersInit( USHORT usTim1Timerout50us )
{
	u16 PrescalerValue;
	
	TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
	NVIC_InitTypeDef NVIC_InitStructure;

	//´ò¿ªTIM4ʱÖÓ
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);

	//TIM4·ÖƵϵÊýΪ3599,ʱ»ùƵÂÊΪ72 / (1 + Prescaler) = 20KHz,»ù׼Ϊ50us
	PrescalerValue = (u16) (SystemCoreClock / 20000) - 1; 

	//TIM4³õʼ»¯
	TIM_TimeBaseStructure.TIM_Period = (u16) usTim1Timerout50us;
	TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
	TIM_TimeBaseStructure.TIM_ClockDivision = 0;
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);

	//ʹÄÜTIM4ԤװÔØ
	TIM_ARRPreloadConfig(TIM4, ENABLE);

	//TIM4ÖжÏÅäÖÃ
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
	NVIC_InitStructure.NVIC_IRQChannel = TIM4_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_Init(&NVIC_InitStructure);

	//Çå³ý¸üÐÂÖжϱêÖ¾
	TIM_ClearITPendingBit(TIM4,TIM_IT_Update);

	//ʧÄÜTIM4¸üÐÂÖжÏ
	TIM_ITConfig(TIM4, TIM_IT_Update, DISABLE);

	//¹Ø±ÕTIM4¶¨Ê±Æ÷
	TIM_Cmd(TIM4,  DISABLE);
	
    return TRUE;
}

/**
  * @brief  ¿ªÆôTIM4
  * @param  ÎÞ
  * @retval ÎÞ
  */
void vMBPortTimersEnable(void)
{
    /* Enable the timer with the timeout passed to xMBPortTimersInit( ) */
	
	//Çå³ý¸üÐÂÖжϱêÖ¾
	TIM_ClearITPendingBit(TIM4,TIM_IT_Update);
	
	//ÔÊÐíTIM4¸üÐÂÖжÏ
	TIM_ITConfig(TIM4,TIM_IT_Update,ENABLE);
	
	//½«TIM4¼ÆÊýÖµÇåÁã
	TIM_SetCounter(TIM4,0);
	
	//¿ªÆôTIM4¶¨Ê±Æ÷
	TIM_Cmd(TIM4,ENABLE);
}

/**
  * @brief  ¹Ø±ÕTIM4
  * @param  ÎÞ
  * @retval ÎÞ
  */
void vMBPortTimersDisable(void)
{
    /* Disable any pending timers. */
	
	//Çå³ý¸üÐÂÖжϱêÖ¾
	TIM_ClearITPendingBit(TIM4,TIM_IT_Update);
	
	//½ûÖ¹TIM4¸üÐÂÖжÏ
	TIM_ITConfig(TIM4,TIM_IT_Update,DISABLE);
	
	//½«TIM4¼ÆÊýÖµÇåÁã
	TIM_SetCounter(TIM4,0);
	
	//¹Ø±ÕTIM4¶¨Ê±Æ÷
	TIM_Cmd(TIM4,DISABLE);
}

/* Create an ISR which is called whenever the timer has expired. This function
 * must then call pxMBPortCBTimerExpired( ) to notify the protocol stack that
 * the timer has expired.
 */
static void prvvTIMERExpiredISR(void)
{
    (void)pxMBPortCBTimerExpired();
}

/**
  * @brief  TIM4ÖжϺ¯Êý
  * @param  ÎÞ
  * @retval ÎÞ
  */
void TIM4_IRQHandler(void)
{
	//ÊÇ·ñ·¢ËÍTIM4¸üÐÂÖжÏ
	if (TIM_GetITStatus(TIM4, TIM_IT_Update) != RESET)
	{
		//Çå³ýTIM4¸üÐÂÖжϱêÖ¾
		TIM_ClearITPendingBit(TIM4, TIM_IT_Update);

		prvvTIMERExpiredISR( );
	}
}