Ben Katz / FastPWM2

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Fork of FastPWM by Erik -

Device/FastPWM_KSDK.cpp@26:f74bd3ec7a01, 2015-12-10 (annotated)

Committer:
benkatz
Date:
Thu Dec 10 08:37:14 2015 +0000
Revision:
26:f74bd3ec7a01
Parent:
14:b30038fbba51 
/

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Sissors 14:b30038fbba51 1 #if defined(TARGET_KPSDK_MCUS)
Sissors 14:b30038fbba51 2
Sissors 14:b30038fbba51 3 #include "FastPWM.h"
Sissors 14:b30038fbba51 4 #include "fsl_clock_manager.h"
Sissors 14:b30038fbba51 5
Sissors 14:b30038fbba51 6
Sissors 14:b30038fbba51 7 #define PWM_CNV (*(((fastpwm_struct*)fast_obj)->CnV))
Sissors 14:b30038fbba51 8 #define PWM_MOD (*(((fastpwm_struct*)fast_obj)->MOD))
Sissors 14:b30038fbba51 9 #define PWM_SC (*(((fastpwm_struct*)fast_obj)->SC))
Sissors 14:b30038fbba51 10
Sissors 14:b30038fbba51 11 typedef struct {
Sissors 14:b30038fbba51 12 __IO uint32_t *CnV;
Sissors 14:b30038fbba51 13 __IO uint32_t *MOD;
Sissors 14:b30038fbba51 14 __IO uint32_t *SC;
Sissors 14:b30038fbba51 15 } fastpwm_struct;
Sissors 14:b30038fbba51 16
Sissors 14:b30038fbba51 17 static uint32_t pwm_prescaler;
Sissors 14:b30038fbba51 18
Sissors 14:b30038fbba51 19 void FastPWM::initFastPWM( void ) {
Sissors 14:b30038fbba51 20 fast_obj = new fastpwm_struct;
Sissors 14:b30038fbba51 21 bits = 16;
Sissors 14:b30038fbba51 22
Sissors 14:b30038fbba51 23 uint32_t pwm_base_clock;
Sissors 14:b30038fbba51 24 CLOCK_SYS_GetFreq(kBusClock, &pwm_base_clock);
Sissors 14:b30038fbba51 25 pwm_prescaler = SystemCoreClock / pwm_base_clock;
Sissors 14:b30038fbba51 26
Sissors 14:b30038fbba51 27 uint32_t ftms[] = FTM_BASE_ADDRS;
Sissors 14:b30038fbba51 28 unsigned int ch_n = (_pwm.pwm_name & 0xFF);
Sissors 14:b30038fbba51 29 FTM_Type *ftm = (FTM_Type *)ftms[_pwm.pwm_name >> TPM_SHIFT];
Sissors 14:b30038fbba51 30
Sissors 14:b30038fbba51 31 ((fastpwm_struct*)fast_obj)->CnV = &ftm->CONTROLS[ch_n].CnV;
Sissors 14:b30038fbba51 32 ((fastpwm_struct*)fast_obj)->MOD = &ftm->MOD;
Sissors 14:b30038fbba51 33 ((fastpwm_struct*)fast_obj)->SC = &ftm->SC;
Sissors 14:b30038fbba51 34 }
Sissors 14:b30038fbba51 35
Sissors 14:b30038fbba51 36 void FastPWM::pulsewidth_ticks( uint32_t ticks ) {
Sissors 14:b30038fbba51 37 PWM_CNV = ticks;
Sissors 14:b30038fbba51 38 }
Sissors 14:b30038fbba51 39
Sissors 14:b30038fbba51 40 void FastPWM::period_ticks( uint32_t ticks ) {
Sissors 14:b30038fbba51 41 PWM_MOD = ticks - 1;
Sissors 14:b30038fbba51 42 }
Sissors 14:b30038fbba51 43
Sissors 14:b30038fbba51 44 uint32_t FastPWM::getPeriod( void ) {
Sissors 14:b30038fbba51 45 return PWM_MOD + 1;
Sissors 14:b30038fbba51 46 }
Sissors 14:b30038fbba51 47
Sissors 14:b30038fbba51 48 uint32_t FastPWM::setPrescaler(uint32_t reqScale) {
Sissors 14:b30038fbba51 49
Sissors 14:b30038fbba51 50 uint32_t prescalers[] = {1, 2, 4, 8, 16, 32, 64, 128};
Sissors 14:b30038fbba51 51
Sissors 14:b30038fbba51 52 for (int i = 0; i<8; i++)
Sissors 14:b30038fbba51 53 prescalers[i] = prescalers[i] * pwm_prescaler;
Sissors 14:b30038fbba51 54
Sissors 14:b30038fbba51 55 //If prescaler is 0, return current one
Sissors 14:b30038fbba51 56 if (reqScale == 0)
Sissors 14:b30038fbba51 57 return (prescalers[(PWM_SC) & 0x07]);
Sissors 14:b30038fbba51 58
Sissors 14:b30038fbba51 59 uint32_t retval = 0;
Sissors 14:b30038fbba51 60 char bin;
Sissors 14:b30038fbba51 61
Sissors 14:b30038fbba51 62 for (bin = 0; bin<8; bin++) {
Sissors 14:b30038fbba51 63 retval = prescalers[bin];
Sissors 14:b30038fbba51 64 if (retval >= reqScale)
Sissors 14:b30038fbba51 65 break;
Sissors 14:b30038fbba51 66 }
Sissors 14:b30038fbba51 67 if (bin == 8)
Sissors 14:b30038fbba51 68 bin = 7;
Sissors 14:b30038fbba51 69
Sissors 14:b30038fbba51 70 //Clear lower 5 bits, write new value:
Sissors 14:b30038fbba51 71 char clockbits = PWM_SC & (3<<3);
Sissors 14:b30038fbba51 72
Sissors 14:b30038fbba51 73 //For some reason clearing them takes some effort
Sissors 14:b30038fbba51 74 while ((PWM_SC & 0x1F) != 0)
Sissors 14:b30038fbba51 75 PWM_SC &= ~0x1F;
Sissors 14:b30038fbba51 76
Sissors 14:b30038fbba51 77
Sissors 14:b30038fbba51 78 PWM_SC = bin + clockbits;
Sissors 14:b30038fbba51 79
Sissors 14:b30038fbba51 80 return retval;
Sissors 14:b30038fbba51 81 }
Sissors 14:b30038fbba51 82 #endif