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Ender3V2S1/Marlin/src/HAL/AVR/fast_pwm.cpp

240 lines
9.8 KiB
C++

/**
* Marlin 3D Printer Firmware
* Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
*
* Based on Sprinter and grbl.
* Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*
*/
#ifdef __AVR__
#include "../../inc/MarlinConfig.h"
//#define DEBUG_AVR_FAST_PWM
#define DEBUG_OUT ENABLED(DEBUG_AVR_FAST_PWM)
#include "../../core/debug_out.h"
struct Timer {
volatile uint8_t* TCCRnQ[3]; // max 3 TCCR registers per timer
volatile uint16_t* OCRnQ[3]; // max 3 OCR registers per timer
volatile uint16_t* ICRn; // max 1 ICR register per timer
uint8_t n; // the timer number [0->5]
uint8_t q; // the timer output [0->2] (A->C)
bool isPWM; // True if pin is a "hardware timer"
bool isProtected; // True if timer is protected
};
// Macros for the Timer structure
#define _SET_WGMnQ(T, V) do{ \
*(T.TCCRnQ)[0] = (*(T.TCCRnQ)[0] & ~(0x3 << 0)) | (( int(V) & 0x3) << 0); \
*(T.TCCRnQ)[1] = (*(T.TCCRnQ)[1] & ~(0x3 << 3)) | (((int(V) >> 2) & 0x3) << 3); \
}while(0)
// Set TCCR CS bits
#define _SET_CSn(T, V) (*(T.TCCRnQ)[1] = (*(T.TCCRnQ[1]) & ~(0x7 << 0)) | ((int(V) & 0x7) << 0))
// Set TCCR COM bits
#define _SET_COMnQ(T, Q, V) (*(T.TCCRnQ)[0] = (*(T.TCCRnQ)[0] & ~(0x3 << (6-2*(Q)))) | (int(V) << (6-2*(Q))))
// Set OCRnQ register
#define _SET_OCRnQ(T, Q, V) (*(T.OCRnQ)[Q] = int(V) & 0xFFFF)
// Set ICRn register (one per timer)
#define _SET_ICRn(T, V) (*(T.ICRn) = int(V) & 0xFFFF)
/**
* Return a Timer struct describing a pin's timer.
*/
const Timer get_pwm_timer(const pin_t pin) {
uint8_t q = 0;
switch (digitalPinToTimer(pin)) {
#ifdef TCCR0A
IF_DISABLED(AVR_AT90USB1286_FAMILY, case TIMER0A:)
#endif
#ifdef TCCR1A
case TIMER1A: case TIMER1B:
#endif
break; // Protect reserved timers (TIMER0 & TIMER1)
#ifdef TCCR0A
case TIMER0B: // Protected timer, but allow setting the duty cycle on OCR0B for pin D4 only
return Timer({ { &TCCR0A, nullptr, nullptr }, { (uint16_t*)&OCR0A, (uint16_t*)&OCR0B, nullptr }, nullptr, 0, 1, true, true });
#endif
#if HAS_TCCR2
case TIMER2:
return Timer({ { &TCCR2, nullptr, nullptr }, { (uint16_t*)&OCR2, nullptr, nullptr }, nullptr, 2, 0, true, false });
#elif ENABLED(USE_OCR2A_AS_TOP)
case TIMER2A: break; // Protect TIMER2A since its OCR is used by TIMER2B
case TIMER2B:
return Timer({ { &TCCR2A, &TCCR2B, nullptr }, { (uint16_t*)&OCR2A, (uint16_t*)&OCR2B, nullptr }, nullptr, 2, 1, true, false });
#elif defined(TCCR2A)
case TIMER2B: ++q; case TIMER2A:
return Timer({ { &TCCR2A, &TCCR2B, nullptr }, { (uint16_t*)&OCR2A, (uint16_t*)&OCR2B, nullptr }, nullptr, 2, q, true, false });
#endif
#ifdef OCR3C
case TIMER3C: ++q; case TIMER3B: ++q; case TIMER3A:
return Timer({ { &TCCR3A, &TCCR3B, &TCCR3C }, { &OCR3A, &OCR3B, &OCR3C }, &ICR3, 3, q, true, false });
#elif defined(OCR3B)
case TIMER3B: ++q; case TIMER3A:
return Timer({ { &TCCR3A, &TCCR3B, nullptr }, { &OCR3A, &OCR3B, nullptr }, &ICR3, 3, q, true, false });
#endif
#ifdef TCCR4A
case TIMER4C: ++q; case TIMER4B: ++q; case TIMER4A:
return Timer({ { &TCCR4A, &TCCR4B, &TCCR4C }, { &OCR4A, &OCR4B, &OCR4C }, &ICR4, 4, q, true, false });
#endif
#ifdef TCCR5A
case TIMER5C: ++q; case TIMER5B: ++q; case TIMER5A:
return Timer({ { &TCCR5A, &TCCR5B, &TCCR5C }, { &OCR5A, &OCR5B, &OCR5C }, &ICR5, 5, q, true, false });
#endif
}
return Timer();
}
void MarlinHAL::set_pwm_frequency(const pin_t pin, const uint16_t f_desired) {
DEBUG_ECHOLNPGM("set_pwm_frequency(pin=", pin, ", freq=", f_desired, ")");
const Timer timer = get_pwm_timer(pin);
if (timer.isProtected || !timer.isPWM) return; // Don't proceed if protected timer or not recognized
const bool is_timer2 = timer.n == 2;
const uint16_t maxtop = is_timer2 ? 0xFF : 0xFFFF;
DEBUG_ECHOLNPGM("maxtop=", maxtop);
uint16_t res = 0xFF; // resolution (TOP value)
uint8_t j = CS_NONE; // prescaler index
uint8_t wgm = WGM_PWM_PC_8; // waveform generation mode
// Calculating the prescaler and resolution to use to achieve closest frequency
if (f_desired != 0) {
constexpr uint16_t prescaler[] = { 1, 8, (32), 64, (128), 256, 1024 }; // (*) are Timer 2 only
uint16_t f = (F_CPU) / (uint32_t(maxtop) << 11) + 1; // Start with the lowest non-zero frequency achievable (for 16MHz, 1 or 31)
DEBUG_ECHOLNPGM("f=", f);
DEBUG_ECHOLNPGM("(prescaler loop)");
for (uint8_t i = 0; i < COUNT(prescaler); ++i) { // Loop through all prescaler values
const uint32_t p = prescaler[i]; // Extend to 32 bits for calculations
DEBUG_ECHOLNPGM("prescaler[", i, "]=", p);
uint16_t res_fast_temp, res_pc_temp;
if (is_timer2) {
#if ENABLED(USE_OCR2A_AS_TOP) // No resolution calculation for TIMER2 unless enabled USE_OCR2A_AS_TOP
const uint16_t rft = (F_CPU) / (p * f_desired);
res_fast_temp = rft - 1;
res_pc_temp = rft / 2;
DEBUG_ECHOLNPGM("(Timer2) res_fast_temp=", res_fast_temp, " res_pc_temp=", res_pc_temp);
#else
res_fast_temp = res_pc_temp = maxtop;
DEBUG_ECHOLNPGM("(Timer2) res_fast_temp=", maxtop, " res_pc_temp=", maxtop);
#endif
}
else {
if (p == 32 || p == 128) continue; // Skip TIMER2 specific prescalers when not TIMER2
const uint16_t rft = (F_CPU) / (p * f_desired);
DEBUG_ECHOLNPGM("(Not Timer 2) F_CPU=" STRINGIFY(F_CPU), " prescaler=", p, " f_desired=", f_desired);
res_fast_temp = rft - 1;
res_pc_temp = rft / 2;
}
LIMIT(res_fast_temp, 1U, maxtop);
LIMIT(res_pc_temp, 1U, maxtop);
// Calculate frequencies of test prescaler and resolution values
const uint16_t f_fast_temp = (F_CPU) / (p * (1 + res_fast_temp)),
f_pc_temp = (F_CPU) / ((p * res_pc_temp) << 1),
f_diff = _MAX(f, f_desired) - _MIN(f, f_desired),
f_fast_diff = _MAX(f_fast_temp, f_desired) - _MIN(f_fast_temp, f_desired),
f_pc_diff = _MAX(f_pc_temp, f_desired) - _MIN(f_pc_temp, f_desired);
DEBUG_ECHOLNPGM("f_fast_temp=", f_fast_temp, " f_pc_temp=", f_pc_temp, " f_diff=", f_diff, " f_fast_diff=", f_fast_diff, " f_pc_diff=", f_pc_diff);
if (f_fast_diff < f_diff && f_fast_diff <= f_pc_diff) { // FAST values are closest to desired f
// Set the Wave Generation Mode to FAST PWM
wgm = is_timer2 ? uint8_t(TERN(USE_OCR2A_AS_TOP, WGM2_FAST_PWM_OCR2A, WGM2_FAST_PWM)) : uint8_t(WGM_FAST_PWM_ICRn);
// Remember this combination
f = f_fast_temp; res = res_fast_temp; j = i + 1;
DEBUG_ECHOLNPGM("(FAST) updated f=", f);
}
else if (f_pc_diff < f_diff) { // PHASE CORRECT values are closes to desired f
// Set the Wave Generation Mode to PWM PHASE CORRECT
wgm = is_timer2 ? uint8_t(TERN(USE_OCR2A_AS_TOP, WGM2_PWM_PC_OCR2A, WGM2_PWM_PC)) : uint8_t(WGM_PWM_PC_ICRn);
f = f_pc_temp; res = res_pc_temp; j = i + 1;
DEBUG_ECHOLNPGM("(PHASE) updated f=", f);
}
} // prescaler loop
}
_SET_WGMnQ(timer, wgm);
_SET_CSn(timer, j);
if (is_timer2) {
TERN_(USE_OCR2A_AS_TOP, _SET_OCRnQ(timer, 0, res)); // Set OCR2A value (TOP) = res
}
else
_SET_ICRn(timer, res); // Set ICRn value (TOP) = res
}
void MarlinHAL::set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) {
// If v is 0 or v_size (max), digitalWrite to LOW or HIGH.
// Note that digitalWrite also disables PWM output for us (sets COM bit to 0)
if (v == 0)
digitalWrite(pin, invert);
else if (v == v_size)
digitalWrite(pin, !invert);
else {
const Timer timer = get_pwm_timer(pin);
if (timer.isPWM) {
if (timer.n == 0) {
_SET_COMnQ(timer, timer.q, COM_CLEAR_SET); // Only allow a TIMER0B select...
_SET_OCRnQ(timer, timer.q, v); // ...and OCR0B duty update. For output pin D4 no frequency changes are permitted.
}
else if (!timer.isProtected) {
const uint16_t top = timer.n == 2 ? TERN(USE_OCR2A_AS_TOP, *timer.OCRnQ[0], 255) : *timer.ICRn;
_SET_COMnQ(timer, SUM_TERN(HAS_TCCR2, timer.q, timer.q == 2), COM_CLEAR_SET + invert); // COM20 is on bit 4 of TCCR2, so +1 for q==2
_SET_OCRnQ(timer, timer.q, uint16_t(uint32_t(v) * top / v_size)); // Scale 8/16-bit v to top value
}
}
else
digitalWrite(pin, v < v_size / 2 ? LOW : HIGH);
}
}
void MarlinHAL::init_pwm_timers() {
// Init some timer frequencies to a default 1KHz
const pin_t pwm_pin[] = {
#ifdef __AVR_ATmega2560__
10, 5, 6, 46
#elif defined(__AVR_ATmega1280__)
12, 31
#elif defined(__AVR_ATmega644__) || defined(__AVR_ATmega1284__)
15, 6
#elif defined(__AVR_AT90USB1286__) || defined(__AVR_mega64) || defined(__AVR_mega128)
16, 24
#endif
};
for (uint8_t i = 0; i < COUNT(pwm_pin); ++i)
set_pwm_frequency(pwm_pin[i], 1000);
}
#endif // __AVR__