1 files changed, 68 insertions, 0 deletions
diff --git a/Marlin/src/HAL/STM32F1/fast_pwm.cpp b/Marlin/src/HAL/STM32F1/fast_pwm.cpp
new file mode 100644
index 0000000..884d482
--- /dev/null
+++ b/Marlin/src/HAL/STM32F1/fast_pwm.cpp
@@ -0,0 +1,68 @@
+/**
+ * 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 __STM32F1__
+
+#include "../../inc/MarlinConfigPre.h"
+
+#if NEEDS_HARDWARE_PWM
+
+#include <pwm.h>
+#include "HAL.h"
+#include "timers.h"
+
+void set_pwm_frequency(const pin_t pin, int f_desired) {
+  if (!PWM_PIN(pin)) return;                    // Don't proceed if no hardware timer
+
+  timer_dev *timer = PIN_MAP[pin].timer_device;
+  uint8_t channel = PIN_MAP[pin].timer_channel;
+
+  // Protect used timers
+  if (timer == get_timer_dev(TEMP_TIMER_NUM)) return;
+  if (timer == get_timer_dev(STEP_TIMER_NUM)) return;
+  #if PULSE_TIMER_NUM != STEP_TIMER_NUM
+    if (timer == get_timer_dev(PULSE_TIMER_NUM)) return;
+  #endif
+
+  if (!(timer->regs.bas->SR & TIMER_CR1_CEN))   // Ensure the timer is enabled
+    timer_init(timer);
+
+  timer_set_mode(timer, channel, TIMER_PWM);
+  uint16_t preload = 255;                       // Lock 255 PWM resolution for high frequencies
+  int32_t prescaler = (HAL_TIMER_RATE) / (preload + 1) / f_desired - 1;
+  if (prescaler > 65535) {                      // For low frequencies increase prescaler
+    prescaler = 65535;
+    preload = (HAL_TIMER_RATE) / (prescaler + 1) / f_desired - 1;
+  }
+  if (prescaler < 0) return;                    // Too high frequency
+  timer_set_reload(timer, preload);
+  timer_set_prescaler(timer, prescaler);
+}
+
+void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) {
+  timer_dev *timer = PIN_MAP[pin].timer_device;
+  uint16_t max_val = timer->regs.bas->ARR * v / v_size;
+  if (invert) max_val = v_size - max_val;
+  pwmWrite(pin, max_val);
+}
+
+#endif // NEEDS_HARDWARE_PWM
+#endif // __STM32F1__