pwm.h

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#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h> 
#include <unistd.h>
#include <errno.h>
#include <stdint.h>

#include "types.h"
#include "log.h"

// base addresses
#define PWMSS0_BASE 0x48300000
#define PWMSS1_BASE 0x48302000
#define EPWM_OFFSET 0x0200

// pwm size
#define PWM_SIZE 0x00000FFF

// configuration registers
#define TBCTL   (EPWM_OFFSET+0x0) / sizeof (uint16_t)   // counter control
#define TBPRD   (EPWM_OFFSET+0xA) / sizeof (uint16_t)   // period
#define CMPA    (EPWM_OFFSET+0x12) / sizeof (uint16_t)  // compare
#define CMPB    (EPWM_OFFSET+0x14) / sizeof (uint16_t)  
#define AQCTLA  (EPWM_OFFSET+0x16) / sizeof (uint16_t)  // action qualifier
#define AQCTLB  (EPWM_OFFSET+0x18) / sizeof (uint16_t)  

// register values
#define TBCTL_DEFAULT   0xC000
#define UP_DOWN_COUNT   0x0002
#define PRESCALE2       0x0400


// range switch clock configuration (action qualifier)
#define RWC_AQ_A 0x0060 // set when incrementing, clear when decrementing
#define RWC_AQ_B 0x0900 // set when decrementing, clear when incrementing

// pulse configuration
#define PULSE_WIDTH 0.1 // 10% of sampling period
#define MARGIN 0.1
#define PWM_PERIOD_SCALE 50000000 * (1 + PULSE_WIDTH + MARGIN) // period scaling factor (period is set in 5ns, (/2 clock prescaling))


// ADC clock settings
#define ADC_CLOCK_PERIOD    48      // in 10ns
#define ADC_AQ              0x0025  // clear on zero and period, set at 50%

int pwm_setup(void);
void pwm_close(void);

void range_clock_setup(int sample_rate); // sampling rate [Hz]
void adc_clock_setup(void);