Diff: Device/FastPWM_KSDK.cpp

Revision:

0:16be67f4d9ac

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Device/FastPWM_KSDK.cpp	Tue Sep 19 16:52:01 2017 +0000
@@ -0,0 +1,88 @@
+#if defined(TARGET_KPSDK_MCUS)
+
+#include "FastPWM.h"
+#include "fsl_ftm.h"
+
+
+#define PWM_CNV              (*(((fastpwm_struct*)fast_obj)->CnV))  
+#define PWM_MOD              (*(((fastpwm_struct*)fast_obj)->MOD))  
+#define PWM_SC               (*(((fastpwm_struct*)fast_obj)->SC))  
+#define PWM_SYNC             (*(((fastpwm_struct*)fast_obj)->SYNC))  
+
+typedef struct  {
+    __IO uint32_t *CnV;
+    __IO uint32_t *MOD;
+    __IO uint32_t *SC;
+    __IO uint32_t *SYNC;
+} fastpwm_struct;
+
+static uint32_t pwm_prescaler;
+static FTM_Type *const ftm_addrs[] = FTM_BASE_PTRS;
+
+void FastPWM::initFastPWM( void ) {
+    fast_obj = new fastpwm_struct;
+    bits = 16;
+
+    pwm_prescaler = SystemCoreClock / CLOCK_GetFreq(kCLOCK_BusClk);;
+
+    unsigned int ch_n = (_pwm.pwm_name & 0xF);
+    FTM_Type *ftm = ftm_addrs[_pwm.pwm_name >> TPM_SHIFT];
+    
+    ((fastpwm_struct*)fast_obj)->CnV = &ftm->CONTROLS[ch_n].CnV;
+    ((fastpwm_struct*)fast_obj)->MOD = &ftm->MOD;
+    ((fastpwm_struct*)fast_obj)->SC = &ftm->SC;
+    ((fastpwm_struct*)fast_obj)->SYNC = &ftm->SYNC;
+    
+    //Do not clear counter when writing new value, set end of period as loading value
+    ftm->SYNCONF &= ~FTM_SYNCONF_SWRSTCNT_MASK;
+    ftm->SYNC |= FTM_SYNC_CNTMAX_MASK;
+}
+
+void FastPWM::pulsewidth_ticks( uint32_t ticks ) {
+    PWM_CNV = ticks;
+    PWM_SYNC |= FTM_SYNC_SWSYNC_MASK;
+}
+
+void FastPWM::period_ticks( uint32_t ticks ) {
+    PWM_MOD = ticks - 1;
+    PWM_SYNC |= FTM_SYNC_SWSYNC_MASK;  
+}
+
+uint32_t FastPWM::getPeriod( void ) {
+    return PWM_MOD + 1;
+}
+
+uint32_t FastPWM::setPrescaler(uint32_t reqScale) {
+ 
+    uint32_t prescalers[] = {1, 2, 4, 8, 16, 32, 64, 128};
+    
+    for (int i = 0; i<8; i++)
+         prescalers[i] = prescalers[i] * pwm_prescaler;
+    
+    //If prescaler is 0, return current one
+    if (reqScale == 0)
+        return (prescalers[(PWM_SC) & 0x07]);
+    
+    uint32_t retval = 0;
+    char bin;
+    
+    for (bin = 0; bin<8; bin++) {
+        retval = prescalers[bin];
+        if (retval >= reqScale)
+            break;
+    }
+    if (bin == 8)
+        bin = 7;
+    
+    //Clear lower 5 bits, write new value:
+    char clockbits = PWM_SC & (3<<3);
+    
+    //For some reason clearing them takes some effort
+    while ((PWM_SC & 0x1F) != 0)
+        PWM_SC &= ~0x1F;
+        
+    
+    PWM_SC = bin + clockbits;
+    return retval;   
+}
+#endif
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