#include "RFInput.h"
#include "stm32f1xx_ll_gpio.h" 
#include "stm32f1xx_ll_bus.h"
#include "stm32f1xx_ll_tim.h"
#include <math.h>

// timer 4 channel 1 for pb6 channel 2 for pb7

void RF_INPUT_Init(void)
{
  // GPIO setup
  LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_GPIOB);
  LL_GPIO_InitTypeDef  pb6_init_conf, pb7_init_conf;

  pb6_init_conf.Mode = LL_GPIO_MODE_FLOATING;
  pb6_init_conf.Pin = LL_GPIO_PIN_6;
  pb6_init_conf.Pull = LL_GPIO_PULL_DOWN;
  LL_GPIO_Init(GPIOB, &pb6_init_conf);

  pb7_init_conf.Mode = LL_GPIO_MODE_FLOATING;
  pb7_init_conf.Pin = LL_GPIO_PIN_7;
  pb7_init_conf.Pull = LL_GPIO_PULL_DOWN;
  LL_GPIO_Init(GPIOB, &pb7_init_conf);

  // timer setup to
  LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_TIM4);
  LL_TIM_InitTypeDef tim4_init_struct;

  tim4_init_struct.Autoreload= 0xFFFF;
  tim4_init_struct.Prescaler=71;
  tim4_init_struct.ClockDivision=LL_TIM_CLOCKDIVISION_DIV1;
  tim4_init_struct.CounterMode=LL_TIM_COUNTERMODE_UP;
  tim4_init_struct.RepetitionCounter=0;

  LL_TIM_Init(TIM4, &tim4_init_struct);

  // setup channel 1 to capture period of pwm
  LL_TIM_IC_InitTypeDef tim4_ic_conf;
  tim4_ic_conf.ICPolarity= LL_TIM_IC_POLARITY_RISING;
  tim4_ic_conf.ICActiveInput = LL_TIM_ACTIVEINPUT_DIRECTTI;
  tim4_ic_conf.ICFilter = LL_TIM_IC_FILTER_FDIV1;
  tim4_ic_conf.ICPrescaler = LL_TIM_ICPSC_DIV1;

  LL_TIM_IC_Init(TIM4, LL_TIM_CHANNEL_CH1, &tim4_ic_conf);

  // setup channel 2 to capture duty time of pwm
  LL_TIM_IC_InitTypeDef tim4_ic_conf_2;
  tim4_ic_conf_2.ICPolarity= LL_TIM_IC_POLARITY_FALLING;
  tim4_ic_conf_2.ICActiveInput = LL_TIM_ACTIVEINPUT_INDIRECTTI;
  tim4_ic_conf_2.ICFilter = LL_TIM_IC_FILTER_FDIV1;
  tim4_ic_conf_2.ICPrescaler = LL_TIM_ICPSC_DIV1;

  LL_TIM_IC_Init(TIM4, LL_TIM_CHANNEL_CH2, &tim4_ic_conf_2);

  // setup reset of clock at rising edge
  LL_TIM_SetSlaveMode(TIM4, LL_TIM_SLAVEMODE_RESET);
  LL_TIM_SetTriggerInput(TIM4, LL_TIM_TS_TI1FP1);
  
  LL_TIM_EnableCounter(TIM4);
}

int RF_INPUT_GetPeriodUs(void)
{
  return LL_TIM_ReadReg(TIM4, CCR1);
}

int RF_INPUT_GetDutyTimeUs(void)
{
  return LL_TIM_ReadReg(TIM4, CCR2);
}

int RF_INPUT_GetDutyTimeRelative(void)
{
  int d = RF_INPUT_GetDutyTimeUs();
  return (d - 1500) / (290.0/100);
}