/*!
    \file  main.c
    \brief TIMER2 PWM input capture demo
*/

/*
    Copyright (C) 2017 GigaDevice

    2017-06-06, V1.0.0, firmware for GD32F3x0
*/

#include "gd32f3x0.h"
#include <stdio.h>
#include "gd32f3x0_eval.h"

void gpio_configuration(void);
void timer_configuration(void);
void nvic_configuration(void);
int fputc(int ch, FILE *f);

/* retarget the C library printf function to the USART */
int fputc(int ch, FILE *f)
{
    usart_data_transmit(EVAL_COM1, (uint8_t) ch);
    while (RESET == usart_flag_get(EVAL_COM1,USART_FLAG_TC));
    return ch;
}

/*!
    \brief      configure the GPIO ports
    \param[in]  none
    \param[out] none
    \retval     none
  */
void gpio_configuration(void)
{
    rcu_periph_clock_enable(RCU_GPIOB);

    /*configure PB4 (TIMER2 CH0) as alternate function*/
    gpio_mode_set(GPIOB, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO_PIN_4);
    gpio_output_options_set(GPIOB, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ,GPIO_PIN_4);
    gpio_af_set(GPIOB, GPIO_AF_1, GPIO_PIN_4);

    /*configure PB5 (TIMER2 CH1) as alternate function*/
    gpio_mode_set(GPIOB, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO_PIN_5);
    gpio_output_options_set(GPIOB, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ,GPIO_PIN_5);
    gpio_af_set(GPIOB, GPIO_AF_1, GPIO_PIN_5);
}

/*!
    \brief      configure the nested vectored interrupt controller
    \param[in]  none
    \param[out] none
    \retval     none
  */
void nvic_configuration(void)
{
    nvic_priority_group_set(NVIC_PRIGROUP_PRE1_SUB3);
    nvic_irq_enable(TIMER2_IRQn, 1, 1);
}

/*!
    \brief      configure the TIMER peripheral
    \param[in]  none
    \param[out] none
    \retval     none
  */
void timer_configuration(void)
{
 /* TIMER2 configuration: PWM input mode ------------------------
     the external signal is connected to TIMER2 CH0 pin(PB4)
     the rising edge is used as active edge
     the TIMER2 CH0CV is used to compute the frequency value 
     the TIMER2 CH1CV is used to compute the duty cycle value
  ------------------------------------------------------------ */
    timer_ic_parameter_struct timer_icinitpara;
    timer_parameter_struct timer_initpara;

    rcu_periph_clock_enable(RCU_TIMER2);

    timer_deinit(TIMER2);

    /* TIMER2 configuration */
#ifdef GD32F330
    timer_initpara.prescaler         = 41999;
#endif /* GD32F330 */
#ifdef GD32F350
    timer_initpara.prescaler         = 53999;
#endif /* GD32F350 */
    timer_initpara.alignedmode       = TIMER_COUNTER_EDGE;
    timer_initpara.counterdirection  = TIMER_COUNTER_UP;
    timer_initpara.period            = 65535;
    timer_initpara.clockdivision     = TIMER_CKDIV_DIV1;
    timer_initpara.repetitioncounter = 0;
    timer_init(TIMER2,&timer_initpara);

    /* TIMER2 configuration */
    /* TIMER2 CH0 PWM input capture configuration */
    timer_icinitpara.icpolarity  = TIMER_IC_POLARITY_RISING;
    timer_icinitpara.icselection = TIMER_IC_SELECTION_DIRECTTI;
    timer_icinitpara.icprescaler = TIMER_IC_PSC_DIV1;
    timer_icinitpara.icfilter    = 0x0;
    timer_input_pwm_capture_config(TIMER2,TIMER_CH_0,&timer_icinitpara);

    /* slave mode selection: TIMER2 */
    timer_input_trigger_source_select(TIMER2,TIMER_SMCFG_TRGSEL_CI0FE0);
    timer_slave_mode_select(TIMER2,TIMER_SLAVE_MODE_RESTART);

    /* select the master slave mode */
    timer_master_slave_mode_config(TIMER2,TIMER_MASTER_SLAVE_MODE_ENABLE);

    /* auto-reload preload enable */
    timer_auto_reload_shadow_enable(TIMER2);
    /* clear channel 0 interrupt bit */
    timer_interrupt_flag_clear(TIMER2,TIMER_INT_CH0);
    /* channel 0 interrupt enable */
    timer_interrupt_enable(TIMER2,TIMER_INT_CH0);

    /* TIMER2 counter enable */
    timer_enable(TIMER2);
}

/*!
    \brief      main function
    \param[in]  none
    \param[out] none
    \retval     none
*/
int main(void)
{
    gpio_configuration(); 
    gd_eval_com_init(EVAL_COM1);
    nvic_configuration();
    timer_configuration();

    while (1);
}
