/**
  ******************************************************************************
  * @file    Examples_LL/TIM/TIM_OutputCompare/Src/main.c
  * @author  MCD Application Team
  * @brief   This example describes how to use a timer instance in output 
  *          compare mode using the STM32F1xx TIM LL API.
  *          Peripheral initialization done using LL unitary services functions.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2016 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "main.h"

/** @addtogroup STM32F1xx_LL_Examples
  * @{
  */

/** @addtogroup TIM_OutputCompare
  * @{
  */

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Number of output compare modes */
#define TIM_OC_MODES_NB 3

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Output compare modes */
static uint32_t aOCMode[TIM_OC_MODES_NB] = {
  LL_TIM_OCMODE_TOGGLE,
  LL_TIM_OCMODE_ACTIVE,
  LL_TIM_OCMODE_INACTIVE
};

/* Output compare mode index */
static uint8_t iOCMode = 0;

/* Compare match count */
static uint32_t uwCompareMatchCount = 0;

/* TIM2 Clock */
static uint32_t TimOutClock = 1;

/* Private function prototypes -----------------------------------------------*/
__STATIC_INLINE void     SystemClock_Config(void);
__STATIC_INLINE void     Configure_TIMOutputCompare(void);
__STATIC_INLINE void     Configure_OCMode(uint32_t OCMode);
__STATIC_INLINE void     UserButton_Init(void);

/* Private functions ---------------------------------------------------------*/

/**
  * @brief  Main program
  * @param  None
  * @retval None
  */
int main(void)
{
  /* Configure the system clock to 72 MHz */
  SystemClock_Config();

  /* Initialize button in EXTI mode */
  UserButton_Init();
  
  /* Configure the timer in output compare mode */
  Configure_TIMOutputCompare();

  /* Infinite loop */
  while (1)
  {
  }
}

/**
  * @brief  Configures the timer to generate an output compare signal on the 
  *         OC1 output.
  * @note   Peripheral configuration is minimal configuration from reset values.
  *         Thus, some useless LL unitary functions calls below are provided as
  *         commented examples - setting is default configuration from reset.
  * @param  None
  * @retval None
  */
__STATIC_INLINE void  Configure_TIMOutputCompare(void)
{
  /*************************/
  /* GPIO AF configuration */
  /*************************/
  /* Enable the peripheral clock of GPIOs */
  LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_GPIOA);

  /* GPIO TIM2_CH1 configuration */
  LL_GPIO_SetPinMode(GPIOA, LL_GPIO_PIN_0, LL_GPIO_MODE_ALTERNATE);
  LL_GPIO_SetPinPull(GPIOA, LL_GPIO_PIN_0, LL_GPIO_PULL_DOWN);
  LL_GPIO_SetPinSpeed(GPIOA, LL_GPIO_PIN_0, LL_GPIO_SPEED_FREQ_HIGH);

  /***********************************************/
  /* Configure the NVIC to handle TIM2 interrupt */
  /***********************************************/
  NVIC_SetPriority(TIM2_IRQn, 0);
  NVIC_EnableIRQ(TIM2_IRQn);
  
  /******************************/
  /* Peripheral clocks enabling */
  /******************************/
  /* Enable the timer peripheral clock */
  LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_TIM2); 
  
  /***************************/
  /* Time base configuration */
  /***************************/
  /* Set counter mode */
  /* Reset value is LL_TIM_COUNTERMODE_UP */
  //LL_TIM_SetCounterMode(TIM2, LL_TIM_COUNTERMODE_UP);
  
  /* Set the pre-scaler value to have TIM2 counter clock equal to 10 kHz */
  LL_TIM_SetPrescaler(TIM2, __LL_TIM_CALC_PSC(SystemCoreClock, 10000));
  
  /* Set the auto-reload value to have a counter frequency of 10 Hz */
  /* TIM2CLK = SystemCoreClock / (APB prescaler & multiplier)               */
  TimOutClock = SystemCoreClock/2;
  LL_TIM_SetAutoReload(TIM2, __LL_TIM_CALC_ARR(TimOutClock, LL_TIM_GetPrescaler(TIM2), 10));
    
  /*********************************/
  /* Output waveform configuration */
  /*********************************/
  /* Set output compare mode: TOGGLE */ 
  LL_TIM_OC_SetMode(TIM2, LL_TIM_CHANNEL_CH1, LL_TIM_OCMODE_TOGGLE);

  /* Set output channel polarity: OC is active high */
  LL_TIM_OC_SetPolarity(TIM2, LL_TIM_CHANNEL_CH1, LL_TIM_OCPOLARITY_HIGH);
  
  /* Set output compare active/inactive delay to half of the auto-reload value */
  LL_TIM_OC_SetCompareCH1(TIM2, (LL_TIM_GetAutoReload(TIM2) / 2));
  
  /**************************/
  /* TIM2 interrupts set-up */
  /**************************/
  /* Enable the capture/compare interrupt for channel 1*/
  LL_TIM_EnableIT_CC1(TIM2);
  
  /**********************************/
  /* Start output signal generation */
  /**********************************/
  /* Enable output channel 1 */
  LL_TIM_CC_EnableChannel(TIM2, LL_TIM_CHANNEL_CH1);
    
  /* Enable counter */
  LL_TIM_EnableCounter(TIM2);
  
  /* Force update generation */
  LL_TIM_GenerateEvent_UPDATE(TIM2);
}

/**
  * @brief  Changes the output compare mode.
  * @param  None
  * @retval None
  */
__STATIC_INLINE void Configure_OCMode(uint32_t OCMode)
{
  /* Disable the counter */
  LL_TIM_DisableCounter(TIM2);
  
  /* Reset the counter */
  LL_TIM_SetCounter(TIM2, 0);
  
  /* Reset the compare match count */
  uwCompareMatchCount = 0;
  
  /* Set the output level (active v.s. inactive) according to the new OC mode */
  switch (OCMode)
  {
    case LL_TIM_OCMODE_TOGGLE:
    case LL_TIM_OCMODE_ACTIVE:
      /* Set the output channel to its inactive level (LOW)*/
      LL_TIM_OC_SetMode(TIM2, LL_TIM_CHANNEL_CH1, LL_TIM_OCMODE_FORCED_INACTIVE);
      break;
      
    case LL_TIM_OCMODE_INACTIVE:
      /* Set the output channel to its active level (HIGH)*/
      LL_TIM_OC_SetMode(TIM2, LL_TIM_CHANNEL_CH1, LL_TIM_OCMODE_FORCED_ACTIVE);
      break;
        
    default:
      break;
  }
  
  /* Update the output channel mode */
  LL_TIM_OC_SetMode(TIM2, LL_TIM_CHANNEL_CH1, OCMode);
  
  /* Re-enable the counter */
  LL_TIM_EnableCounter(TIM2);
}

/**
  * @brief  Configures User push-button in GPIO or EXTI Line Mode.
  * @param  None  
  * @retval None
  */
__STATIC_INLINE void UserButton_Init(void)
{
  /* Enable the BUTTON Clock */
  USER_BUTTON_GPIO_CLK_ENABLE();
  
  /* Configure GPIO for BUTTON */
  LL_GPIO_SetPinMode(USER_BUTTON_GPIO_PORT, USER_BUTTON_PIN, LL_GPIO_MODE_INPUT);
  LL_GPIO_SetPinPull(USER_BUTTON_GPIO_PORT, USER_BUTTON_PIN, LL_GPIO_PULL_DOWN);

  /* Connect External Line to the GPIO*/
  USER_BUTTON_SYSCFG_SET_EXTI();
    
  /* Enable a rising trigger EXTI line 13 Interrupt */
  USER_BUTTON_EXTI_LINE_ENABLE();
  USER_BUTTON_EXTI_FALLING_TRIG_ENABLE();
    
  /* Configure NVIC for USER_BUTTON_EXTI_IRQn */
  NVIC_EnableIRQ(USER_BUTTON_EXTI_IRQn); 
  NVIC_SetPriority(USER_BUTTON_EXTI_IRQn,0x03);  
}

/**
  * @brief  System Clock Configuration
  *         The system Clock is configured as follow :
  *            System Clock source            = PLL (HSE)
  *            SYSCLK(Hz)                     = 72000000
  *            HCLK(Hz)                       = 72000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 2
  *            APB2 Prescaler                 = 1
  *            HSE Frequency(Hz)              = 8000000
  *            PLLMUL                         = 9
  *            Flash Latency(WS)              = 2
  * @param  None
  * @retval None
  */
void SystemClock_Config(void)
{
  /* Set FLASH latency */
  LL_FLASH_SetLatency(LL_FLASH_LATENCY_2);

  /* Enable HSE oscillator */
  LL_RCC_HSE_EnableBypass();
  LL_RCC_HSE_Enable();
  while(LL_RCC_HSE_IsReady() != 1)
  {
  };

  /* Main PLL configuration and activation */
  LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_HSE_DIV_1, LL_RCC_PLL_MUL_9);

  LL_RCC_PLL_Enable();
  while(LL_RCC_PLL_IsReady() != 1)
  {
  };

  /* Sysclk activation on the main PLL */
  LL_RCC_SetAHBPrescaler(LL_RCC_SYSCLK_DIV_1);
  LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_PLL);
  while(LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_PLL)
  {
  };

  /* Set APB1 & APB2 prescaler*/
  LL_RCC_SetAPB1Prescaler(LL_RCC_APB1_DIV_2);
  LL_RCC_SetAPB2Prescaler(LL_RCC_APB2_DIV_1);

  /* Set systick to 1ms in using frequency set to 72MHz */
  LL_Init1msTick(72000000);

  /* Update CMSIS variable (which can be updated also through SystemCoreClockUpdate function) */
  LL_SetSystemCoreClock(72000000);
}

/******************************************************************************/
/*   USER IRQ HANDLER TREATMENT                                               */
/******************************************************************************/
/**
  * @brief  User button interrupt processing
  * @param  None
  * @retval None
  */
void UserButton_Callback(void)
{
  /* Set new OC mode */
  iOCMode = (iOCMode + 1) % TIM_OC_MODES_NB;
    
  /* Switch to next OC mode */
  Configure_OCMode(aOCMode[iOCMode]);
}

/**
  * @brief  Timer capture/compare interrupt processing
  * @note   The capture/compare interrupt is generated whatever the compare
  *         mode is (as long as the timer counter is enabled).
  * @param  None
  * @retval None
  */
void TimerCaptureCompare_Callback(void)
{
   /* Upon compare match, the counter value  should be equal to the */
  /* capture/compare register (TIMx_CCRx) value.                    */
  if(LL_TIM_GetCounter(TIM2) == LL_TIM_OC_GetCompareCH1(TIM2))
  {
    /* Increment the compare match count */
    uwCompareMatchCount++;
  }
}

#ifdef  USE_FULL_ASSERT

/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d", file, line) */

  /* Infinite loop */
  while (1)
  {
  }
}
#endif

/**
  * @}
  */

/**
  * @}
  */