framework-arduinoteensy-cxx20/libraries/FreqMeasureMulti/FreqMeasureMulti.cpp

/* FreqMeasure Library, for measuring relatively low frequencies
 * http://www.pjrc.com/teensy/td_libs_FreqMeasure.html
 * Copyright (c) 2015 PJRC.COM, LLC - Paul Stoffregen <paul@pjrc.com>
 * Extended 2016 by Thierry Frenkel <theremingenieur@gmail.com>
 *
 * Version 0.22
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "FreqMeasureMulti.h"
#if ! defined(__IMXRT1062__)

#define FTM_SC_VALUE (FTM_SC_TOIE | FTM_SC_CLKS(1) | FTM_SC_PS(0))
#define FTM_CSC_RAISING (FTM_CSC_CHIE | FTM_CSC_ELSA)
#define FTM_CSC_FALLING (FTM_CSC_CHIE | FTM_CSC_ELSB)
#define UPDATE_ON_RAISING 1
#define UPDATE_ON_FALLING 2
#define UPDATE_DIFFERENCE 4

static uint8_t channelmask = 0;
static uint16_t capture_msw = 0;
static FreqMeasureMulti * list[8];

bool FreqMeasureMulti::begin(uint32_t pin) {
	return begin(pin, FREQMEASUREMULTI_RAISING);
}

bool FreqMeasureMulti::begin(uint32_t pin, uint8_t mode)
{
	uint8_t capture_mode;
	switch (pin) {
		case 22: channel = 0; CORE_PIN22_CONFIG = PORT_PCR_MUX(4); break;
		case 23: channel = 1; CORE_PIN23_CONFIG = PORT_PCR_MUX(4); break;
		case  9: channel = 2; CORE_PIN9_CONFIG  = PORT_PCR_MUX(4); break;
		case 10: channel = 3; CORE_PIN10_CONFIG = PORT_PCR_MUX(4); break;
		case  6: channel = 4; CORE_PIN6_CONFIG  = PORT_PCR_MUX(4); break;
		case 20: channel = 5; CORE_PIN20_CONFIG = PORT_PCR_MUX(4); break;
#if defined(KINETISK)
		case 21: channel = 6; CORE_PIN21_CONFIG = PORT_PCR_MUX(4); break;
		case  5: channel = 7; CORE_PIN5_CONFIG  = PORT_PCR_MUX(4); break;
#endif
		default:
			channel = 8;
			return false;
	}
	switch (mode) {
		case FREQMEASUREMULTI_FALLING:
		case FREQMEASUREMULTI_INTERLEAVE:
		case FREQMEASUREMULTI_MARK_ONLY:
		case FREQMEASUREMULTI_SPACE_ONLY:
		case FREQMEASUREMULTI_ALTERNATE:
			capture_mode = mode;
			break;
		default:
			capture_mode = FREQMEASUREMULTI_RAISING;
	}
	act_on_raise = (capture_mode & UPDATE_ON_RAISING);
	act_on_fall = (capture_mode & UPDATE_ON_FALLING);
	read_diff = (capture_mode & UPDATE_DIFFERENCE);

	NVIC_DISABLE_IRQ(IRQ_FTM0);
	if (FTM0_MOD != 0xFFFF || (FTM0_SC & 0x7F) != FTM_SC_VALUE) {
		FTM0_SC = 0;
		FTM0_CNT = 0;
		FTM0_MOD = 0xFFFF;
		FTM0_SC = FTM_SC_VALUE;
		#ifdef KINETISK
		FTM0_MODE = FTM_MODE_WPDIS; //allow reconfiguring the CSC on the fly
		#endif
	}

	capture_msw = 0;
	raiscap_previous = 0;
	fallcap_previous = 0;
	next_is_falling = false;
	buffer_head = 0;
	buffer_tail = 0;

	volatile uint32_t *csc = &FTM0_C0SC + channel * 2;
	#if defined(KINETISL)
	*csc = 0;
	delayMicroseconds(1);
	#endif
	*csc = FTM_CSC_RAISING; // first capture is always rising

	list[channel] = this;
	channelmask |= (1 << channel);
	NVIC_SET_PRIORITY(IRQ_FTM0, 48);
	NVIC_ENABLE_IRQ(IRQ_FTM0);
	return true;
}

uint32_t FreqMeasureMulti::available(void)
{
	uint32_t head = buffer_head;
	uint32_t tail = buffer_tail;
	if (head >= tail) return head - tail;
	return FREQMEASUREMULTI_BUFFER_LEN + head - tail;
}

uint32_t FreqMeasureMulti::read(void)
{
	uint32_t head = buffer_head;
	uint32_t tail = buffer_tail;
	if (head == tail) return 0xFFFFFFFF;
	tail = tail + 1;
	if (tail >= FREQMEASUREMULTI_BUFFER_LEN) tail = 0;
	uint32_t value = buffer_value[tail].count;
	last_read_level = buffer_value[tail].level;
	buffer_tail = tail;
	return value;
}

uint8_t FreqMeasureMulti::readLevel(void)
{
	return last_read_level;
}

float FreqMeasureMulti::countToFrequency(uint32_t count)
{
#if defined(__arm__) && defined(TEENSYDUINO) && defined(KINETISK)
	return (float)F_BUS / (float)count;
#elif defined(__arm__) && defined(TEENSYDUINO) && defined(KINETISL)
	return (float)(F_PLL/2) / (float)count;
#else
	return 0.0;
#endif
}

float FreqMeasureMulti::countToNanoseconds(uint32_t count)
{
#if defined(__arm__) && defined(TEENSYDUINO) && defined(KINETISK)
	return (float)count * (1000000000.0f / (float)F_BUS);
#elif defined(__arm__) && defined(TEENSYDUINO) && defined(KINETISL)
	return (float)count * (2000000000.0f / (float)F_PLL);
#else
	return 0.0;
#endif
}

void FreqMeasureMulti::end(void)
{
	switch (channel) {
		case 0: CORE_PIN22_CONFIG = 0; break;
		case 1: CORE_PIN23_CONFIG = 0; break;
		case 2: CORE_PIN9_CONFIG  = 0; break;
		case 3: CORE_PIN10_CONFIG = 0; break;
		case 4: CORE_PIN6_CONFIG  = 0; break;
		case 5: CORE_PIN20_CONFIG = 0; break;
#if defined(KINETISK)
		case 6: CORE_PIN21_CONFIG = 0; break;
		case 7: CORE_PIN5_CONFIG  = 0; break;
#endif
		default: return;
	}
	channelmask &= ~(1 << channel);
	volatile uint32_t *csc = &FTM0_C0SC + channel * 2;
	*csc = 0;
}

void ftm0_isr(void)
{
	bool inc = false;
	if (FTM0_SC & FTM_SC_TOF) {
		#if defined(KINETISK)
		FTM0_SC = FTM_SC_VALUE;
		#elif defined(KINETISL)
		FTM0_SC = FTM_SC_VALUE | FTM_SC_TOF;
		#endif
		capture_msw++;
		inc = true;
	}
	uint8_t mask = FTM0_STATUS & channelmask;
	if ((mask & 0x01)) list[0]->isr(inc);
	if ((mask & 0x02)) list[1]->isr(inc);
	if ((mask & 0x04)) list[2]->isr(inc);
	if ((mask & 0x08)) list[3]->isr(inc);
	if ((mask & 0x10)) list[4]->isr(inc);
	if ((mask & 0x20)) list[5]->isr(inc);
	#if defined(KINETISK)
	if ((mask & 0x40)) list[6]->isr(inc);
	if ((mask & 0x80)) list[7]->isr(inc);
	#endif
}

void FreqMeasureMulti::isr(bool inc)
{
	uint32_t period = 0;
	uint8_t level = LEVEL_UNDEFINED;
	volatile uint32_t *csc = &FTM0_C0SC + channel * 2;
	uint32_t capture = csc[1];
	next_is_falling = !next_is_falling; // toggle capture mode
	#if defined(KINETISK)
	csc[0] = (next_is_falling ? FTM_CSC_FALLING : FTM_CSC_RAISING);
	#elif defined(KINETISL)
	csc[0] = 0; // disable
	asm volatile ("nop");
	asm volatile ("nop");
	csc[0] = (next_is_falling ? FTM_CSC_FALLING : FTM_CSC_RAISING) | FTM_CSC_CHF;
	#endif
	if (capture <= 0xE000 || !inc) {
		capture |= (capture_msw << 16);
	} else {
		capture |= ((capture_msw - 1) << 16);
	}
	// compute the waveform period
	if (next_is_falling) {
		if (act_on_raise) period = capture - (read_diff ? fallcap_previous : raiscap_previous);
		raiscap_previous = capture;
		level = (read_diff ? LEVEL_SPACE_ONLY : LEVEL_MARK_SPACE);
	} else if (!next_is_falling ) {
		if (act_on_fall) period = capture - (read_diff ? raiscap_previous : fallcap_previous);
		fallcap_previous = capture;
		level = (read_diff ? LEVEL_MARK_ONLY : LEVEL_SPACE_MARK);
	}
	if (period != 0) {
		uint32_t i = buffer_head + 1;
		if (i >= FREQMEASUREMULTI_BUFFER_LEN) i = 0;
		if (i != buffer_tail) {
			buffer_value[i].level = level;
			buffer_value[i].count = period;
			buffer_head = i;
		}
	}
}

#endif