/**
 ******************************************************************************
 * @addtogroup OpenPilotBL OpenPilot BootLoader
 * @{
 *
 * @file       stopwatch.c
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 * @brief      Timer functions for the LED PWM.
 * @see        The GNU Public License (GPL) Version 3
 *
 *****************************************************************************/
/*
 * This program 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.
 *
 * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/////////////////////////////////////////////////////////////////////////////
// Include files
/////////////////////////////////////////////////////////////////////////////

#include "stm32f10x_tim.h"

/////////////////////////////////////////////////////////////////////////////
// Local definitions
/////////////////////////////////////////////////////////////////////////////

//#define STOPWATCH_TIMER_BASE                 TIM6
//#define STOPWATCH_TIMER_RCC   RCC_APB1Periph_TIM6

uint32_t STOPWATCH_Init(u32 resolution, TIM_TypeDef* TIM) {
	uint32_t STOPWATCH_TIMER_RCC;
	switch ((uint32_t)TIM) {
	case (uint32_t)TIM1: STOPWATCH_TIMER_RCC = RCC_APB2Periph_TIM1;break;
	case (uint32_t)TIM2: STOPWATCH_TIMER_RCC = RCC_APB1Periph_TIM2; break;
	case (uint32_t)TIM3: STOPWATCH_TIMER_RCC = RCC_APB1Periph_TIM3; break;
	case (uint32_t)TIM4: STOPWATCH_TIMER_RCC = RCC_APB1Periph_TIM4; break;
	default:
		STOPWATCH_TIMER_RCC = RCC_APB2Periph_TIM1;
	}

	// enable timer clock
	if (STOPWATCH_TIMER_RCC == RCC_APB2Periph_TIM1 || STOPWATCH_TIMER_RCC
			== RCC_APB2Periph_TIM8)
		RCC_APB2PeriphClockCmd(STOPWATCH_TIMER_RCC, ENABLE);
	else
		RCC_APB1PeriphClockCmd(STOPWATCH_TIMER_RCC, ENABLE);

	// time base configuration
	TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
	TIM_TimeBaseStructure.TIM_Period = 0xffff; // max period
	TIM_TimeBaseStructure.TIM_Prescaler = (72 * resolution) - 1; // <resolution> uS accuracy @ 72 MHz
	TIM_TimeBaseStructure.TIM_ClockDivision = 0;
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseInit(TIM, &TIM_TimeBaseStructure);

	// enable interrupt request
	TIM_ITConfig(TIM, TIM_IT_Update, ENABLE);

	// start counter
	TIM_Cmd(TIM, ENABLE);

	return 0; // no error
}

/////////////////////////////////////////////////////////////////////////////
//! Resets the stopwatch
//! \return < 0 on errors
/////////////////////////////////////////////////////////////////////////////
uint32_t STOPWATCH_Reset(TIM_TypeDef* TIM) {
	// reset counter
	TIM->CNT = 1; // set to 1 instead of 0 to avoid new IRQ request
	TIM_ClearITPendingBit(TIM, TIM_IT_Update);

	return 0; // no error
}

/////////////////////////////////////////////////////////////////////////////
//! Returns current value of stopwatch
//! \return 1..65535: valid stopwatch value
//! \return 0xffffffff: counter overrun
/////////////////////////////////////////////////////////////////////////////
uint32_t STOPWATCH_ValueGet(TIM_TypeDef* TIM) {
	uint32_t value = TIM->CNT;

	if (TIM_GetITStatus(TIM, TIM_IT_Update) != RESET)
		value = 0xffffffff;

	return value;
}

