diff options
Diffstat (limited to 'Marlin/src/HAL/AVR/fast_pwm.cpp')
| -rw-r--r-- | Marlin/src/HAL/AVR/fast_pwm.cpp | 282 |
1 files changed, 282 insertions, 0 deletions
diff --git a/Marlin/src/HAL/AVR/fast_pwm.cpp b/Marlin/src/HAL/AVR/fast_pwm.cpp new file mode 100644 index 0000000..238c112 --- /dev/null +++ b/Marlin/src/HAL/AVR/fast_pwm.cpp @@ -0,0 +1,282 @@ +/** + * 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/MarlinConfigPre.h" + +#if NEEDS_HARDWARE_PWM // Specific meta-flag for features that mandate PWM + +#include "HAL.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) +}; + +/** + * get_pwm_timer + * Get the timer information and register of the provided pin. + * Return a Timer struct containing this information. + * Used by set_pwm_frequency, set_pwm_duty + */ +Timer get_pwm_timer(const pin_t pin) { + uint8_t q = 0; + switch (digitalPinToTimer(pin)) { + // Protect reserved timers (TIMER0 & TIMER1) + #ifdef TCCR0A + #if !AVR_AT90USB1286_FAMILY + case TIMER0A: + #endif + case TIMER0B: + #endif + #ifdef TCCR1A + case TIMER1A: case TIMER1B: + #endif + break; + #if defined(TCCR2) || defined(TCCR2A) + #ifdef TCCR2 + case TIMER2: { + Timer timer = { + /*TCCRnQ*/ { &TCCR2, nullptr, nullptr }, + /*OCRnQ*/ { (uint16_t*)&OCR2, nullptr, nullptr }, + /*ICRn*/ nullptr, + /*n, q*/ 2, 0 + }; + } + #elif defined(TCCR2A) + #if ENABLED(USE_OCR2A_AS_TOP) + case TIMER2A: break; // protect TIMER2A + case TIMER2B: { + Timer timer = { + /*TCCRnQ*/ { &TCCR2A, &TCCR2B, nullptr }, + /*OCRnQ*/ { (uint16_t*)&OCR2A, (uint16_t*)&OCR2B, nullptr }, + /*ICRn*/ nullptr, + /*n, q*/ 2, 1 + }; + return timer; + } + #else + case TIMER2B: ++q; + case TIMER2A: { + Timer timer = { + /*TCCRnQ*/ { &TCCR2A, &TCCR2B, nullptr }, + /*OCRnQ*/ { (uint16_t*)&OCR2A, (uint16_t*)&OCR2B, nullptr }, + /*ICRn*/ nullptr, + 2, q + }; + return timer; + } + #endif + #endif + #endif + #ifdef OCR3C + case TIMER3C: ++q; + case TIMER3B: ++q; + case TIMER3A: { + Timer timer = { + /*TCCRnQ*/ { &TCCR3A, &TCCR3B, &TCCR3C }, + /*OCRnQ*/ { &OCR3A, &OCR3B, &OCR3C }, + /*ICRn*/ &ICR3, + /*n, q*/ 3, q + }; + return timer; + } + #elif defined(OCR3B) + case TIMER3B: ++q; + case TIMER3A: { + Timer timer = { + /*TCCRnQ*/ { &TCCR3A, &TCCR3B, nullptr }, + /*OCRnQ*/ { &OCR3A, &OCR3B, nullptr }, + /*ICRn*/ &ICR3, + /*n, q*/ 3, q + }; + return timer; + } + #endif + #ifdef TCCR4A + case TIMER4C: ++q; + case TIMER4B: ++q; + case TIMER4A: { + Timer timer = { + /*TCCRnQ*/ { &TCCR4A, &TCCR4B, &TCCR4C }, + /*OCRnQ*/ { &OCR4A, &OCR4B, &OCR4C }, + /*ICRn*/ &ICR4, + /*n, q*/ 4, q + }; + return timer; + } + #endif + #ifdef TCCR5A + case TIMER5C: ++q; + case TIMER5B: ++q; + case TIMER5A: { + Timer timer = { + /*TCCRnQ*/ { &TCCR5A, &TCCR5B, &TCCR5C }, + /*OCRnQ*/ { &OCR5A, &OCR5B, &OCR5C }, + /*ICRn*/ &ICR5, + /*n, q*/ 5, q + }; + return timer; + } + #endif + } + Timer timer = { + /*TCCRnQ*/ { nullptr, nullptr, nullptr }, + /*OCRnQ*/ { nullptr, nullptr, nullptr }, + /*ICRn*/ nullptr, + 0, 0 + }; + return timer; +} + +void set_pwm_frequency(const pin_t pin, int f_desired) { + Timer timer = get_pwm_timer(pin); + if (timer.n == 0) return; // Don't proceed if protected timer or not recognised + uint16_t size; + if (timer.n == 2) size = 255; else size = 65535; + + uint16_t res = 255; // resolution (TOP value) + uint8_t j = 0; // prescaler index + uint8_t wgm = 1; // waveform generation mode + + // Calculating the prescaler and resolution to use to achieve closest frequency + if (f_desired != 0) { + int f = (F_CPU) / (2 * 1024 * size) + 1; // Initialize frequency as lowest (non-zero) achievable + uint16_t prescaler[] = { 0, 1, 8, /*TIMER2 ONLY*/32, 64, /*TIMER2 ONLY*/128, 256, 1024 }; + + // loop over prescaler values + LOOP_S_L_N(i, 1, 8) { + uint16_t res_temp_fast = 255, res_temp_phase_correct = 255; + if (timer.n == 2) { + // No resolution calculation for TIMER2 unless enabled USE_OCR2A_AS_TOP + #if ENABLED(USE_OCR2A_AS_TOP) + const uint16_t rtf = (F_CPU) / (prescaler[i] * f_desired); + res_temp_fast = rtf - 1; + res_temp_phase_correct = rtf / 2; + #endif + } + else { + // Skip TIMER2 specific prescalers when not TIMER2 + if (i == 3 || i == 5) continue; + const uint16_t rtf = (F_CPU) / (prescaler[i] * f_desired); + res_temp_fast = rtf - 1; + res_temp_phase_correct = rtf / 2; + } + + LIMIT(res_temp_fast, 1U, size); + LIMIT(res_temp_phase_correct, 1U, size); + // Calculate frequencies of test prescaler and resolution values + const int f_temp_fast = (F_CPU) / (prescaler[i] * (1 + res_temp_fast)), + f_temp_phase_correct = (F_CPU) / (2 * prescaler[i] * res_temp_phase_correct), + f_diff = ABS(f - f_desired), + f_fast_diff = ABS(f_temp_fast - f_desired), + f_phase_diff = ABS(f_temp_phase_correct - f_desired); + + // If FAST values are closest to desired f + if (f_fast_diff < f_diff && f_fast_diff <= f_phase_diff) { + // Remember this combination + f = f_temp_fast; + res = res_temp_fast; + j = i; + // Set the Wave Generation Mode to FAST PWM + if (timer.n == 2) { + wgm = ( + #if ENABLED(USE_OCR2A_AS_TOP) + WGM2_FAST_PWM_OCR2A + #else + WGM2_FAST_PWM + #endif + ); + } + else wgm = WGM_FAST_PWM_ICRn; + } + // If PHASE CORRECT values are closes to desired f + else if (f_phase_diff < f_diff) { + f = f_temp_phase_correct; + res = res_temp_phase_correct; + j = i; + // Set the Wave Generation Mode to PWM PHASE CORRECT + if (timer.n == 2) { + wgm = ( + #if ENABLED(USE_OCR2A_AS_TOP) + WGM2_PWM_PC_OCR2A + #else + WGM2_PWM_PC + #endif + ); + } + else wgm = WGM_PWM_PC_ICRn; + } + } + } + _SET_WGMnQ(timer.TCCRnQ, wgm); + _SET_CSn(timer.TCCRnQ, j); + + if (timer.n == 2) { + #if ENABLED(USE_OCR2A_AS_TOP) + _SET_OCRnQ(timer.OCRnQ, 0, res); // Set OCR2A value (TOP) = res + #endif + } + else + _SET_ICRn(timer.ICRn, res); // Set ICRn value (TOP) = res +} + +void 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 { + Timer timer = get_pwm_timer(pin); + if (timer.n == 0) return; // Don't proceed if protected timer or not recognised + // Set compare output mode to CLEAR -> SET or SET -> CLEAR (if inverted) + _SET_COMnQ(timer.TCCRnQ, (timer.q + #ifdef TCCR2 + + (timer.q == 2) // COM20 is on bit 4 of TCCR2, thus requires q + 1 in the macro + #endif + ), COM_CLEAR_SET + invert + ); + + uint16_t top; + if (timer.n == 2) { // if TIMER2 + top = ( + #if ENABLED(USE_OCR2A_AS_TOP) + *timer.OCRnQ[0] // top = OCR2A + #else + 255 // top = 0xFF (max) + #endif + ); + } + else + top = *timer.ICRn; // top = ICRn + + _SET_OCRnQ(timer.OCRnQ, timer.q, v * float(top) / float(v_size)); // Scale 8/16-bit v to top value + } +} + +#endif // NEEDS_HARDWARE_PWM +#endif // __AVR__ |