Initial commit

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__