PWM FE310

pwm_fe310.c

#include "pwm_fe310.h"

int pwm_set_comp(const uint8_t comp_val)
{
  if (comp_val > 100)
  {
    printf("Error: PWM duty cycle of more than 100 \% is not possible.\n");
    return 1;
  }
  *PWM_CMP_0_ADDR(PWM0_ADDR) = (uint8_t)(((float)comp_val*255.0)/100.0);
  return 0;
}

int pwm_initialize(const uint8_t pwm_pin, const uint8_t comp_value, const bool xo)
{
  // Make sure 32 bit config register is initialized with all 0
  *PWM_CFG_ADDR(PWM0_ADDR) = 0;
  // Enable PWM and scale the 16 MHz clock with a factor of 2
  *PWM_CFG_ADDR(PWM0_ADDR) |= (1<<PWMENALWAYS) | (0x2<<PWMSCALE);
  // Set count to 0
  *PWM_COUNT_ADDR(PWM0_ADDR) = 0;
  // Set comparator 0 to the initial value
  if (fan_pwm_set_comp(comp_value)) {
    printf("Error: Could not set PWM comparator.\n");
    return 1;
  }
  // Switch MUX to HW function
  *GPIO_IOF_SEL_ADDR(GPIO_ADDR) |= (1<<pwm_pin);
  *GPIO_IOF_EN_ADDR(GPIO_ADDR)  |= (1<<pwm_pin);
  // Enable or disable the XOR at the output GPIO
  if (xo) {
    *GPIO_OUT_XOR(GPIO_ADDR) |= (1<<pwm_pin);
  } else {
    *GPIO_OUT_XOR(GPIO_ADDR) &= ~(1<<pwm_pin);
  }
  if(*PWM_COUNT_ADDR(PWM0_ADDR) == 0)
  {
    printf("Error: PWM is not running.\n");
    return 1;
  }
  return 0;
}