From 3701869e6cdf3fe24b44da8a606575cf4764f872 Mon Sep 17 00:00:00 2001
From: Scott Lahteine <github@thinkyhead.com>
Date: Sun, 3 Jun 2018 01:43:00 -0500
Subject: [PATCH] Add HAL_timer_start for AVR, use stepper timer to time pulses

---
 Marlin/src/HAL/HAL_AVR/HAL.cpp    | 10 +++++----
 Marlin/src/HAL/HAL_AVR/HAL.h      | 35 ++++++++++++++++++++++++++++---
 Marlin/src/module/stepper.cpp     | 23 ++------------------
 Marlin/src/module/temperature.cpp |  9 +-------
 4 files changed, 41 insertions(+), 36 deletions(-)

diff --git a/Marlin/src/HAL/HAL_AVR/HAL.cpp b/Marlin/src/HAL/HAL_AVR/HAL.cpp
index 9c69b90a86..58ee84cbdf 100644
--- a/Marlin/src/HAL/HAL_AVR/HAL.cpp
+++ b/Marlin/src/HAL/HAL_AVR/HAL.cpp
@@ -34,6 +34,7 @@
 // --------------------------------------------------------------------------
 
 #include "../../inc/MarlinConfig.h"
+#include "HAL.h"
 
 // --------------------------------------------------------------------------
 // Externals
@@ -74,9 +75,11 @@
 // --------------------------------------------------------------------------
 
 #if ENABLED(SDSUPPORT)
+
   #include "../../sd/SdFatUtil.h"
   int freeMemory() { return SdFatUtil::FreeRam(); }
-#else
+
+#else // !SDSUPPORT
 
 extern "C" {
   extern char __bss_end;
@@ -93,7 +96,6 @@ extern "C" {
   }
 }
 
-#endif //!SDSUPPORT
-
-#endif
+#endif // !SDSUPPORT
 
+#endif // __AVR__
diff --git a/Marlin/src/HAL/HAL_AVR/HAL.h b/Marlin/src/HAL/HAL_AVR/HAL.h
index 4b84cf5ac7..37fe65ff84 100644
--- a/Marlin/src/HAL/HAL_AVR/HAL.h
+++ b/Marlin/src/HAL/HAL_AVR/HAL.h
@@ -124,7 +124,7 @@ extern "C" {
 
 #define STEP_TIMER_NUM          1
 #define TEMP_TIMER_NUM          0
-#define PULSE_TIMER_NUM         TEMP_TIMER_NUM
+#define PULSE_TIMER_NUM         STEP_TIMER_NUM
 
 #define HAL_STEPPER_TIMER_RATE  HAL_TIMER_RATE
 #define HAL_TICKS_PER_US        ((HAL_STEPPER_TIMER_RATE) / 1000000) // Cannot be of type double
@@ -139,7 +139,7 @@ extern "C" {
 #define TIMER_OCR_0             OCR0A
 #define TIMER_COUNTER_0         TCNT0
 
-#define PULSE_TIMER_PRESCALE    8
+#define PULSE_TIMER_PRESCALE    STEPPER_TIMER_PRESCALE
 
 #define ENABLE_STEPPER_DRIVER_INTERRUPT()  SBI(TIMSK1, OCIE1A)
 #define DISABLE_STEPPER_DRIVER_INTERRUPT() CBI(TIMSK1, OCIE1A)
@@ -149,7 +149,36 @@ extern "C" {
 #define DISABLE_TEMPERATURE_INTERRUPT()    CBI(TIMSK0, OCIE0B)
 #define TEMPERATURE_ISR_ENABLED()         TEST(TIMSK0, OCIE0B)
 
-#define HAL_timer_start(timer_num, frequency)
+FORCE_INLINE void HAL_timer_start(const uint8_t timer_num, const uint32_t frequency) {
+  UNUSED(frequency);
+  switch (timer_num) {
+    case STEP_TIMER_NUM:
+      // waveform generation = 0100 = CTC
+      SET_WGM(1, CTC_OCRnA);
+
+      // output mode = 00 (disconnected)
+      SET_COMA(1, NORMAL);
+
+      // Set the timer pre-scaler
+      // Generally we use a divider of 8, resulting in a 2MHz timer
+      // frequency on a 16MHz MCU. If you are going to change this, be
+      // sure to regenerate speed_lookuptable.h with
+      // create_speed_lookuptable.py
+      SET_CS(1, PRESCALER_8);  //  CS 2 = 1/8 prescaler
+
+      // Init Stepper ISR to 122 Hz for quick starting
+      // (F_CPU) / (STEPPER_TIMER_PRESCALE) / frequency
+      OCR1A = 0x4000;
+      TCNT1 = 0;
+      break;
+
+    case TEMP_TIMER_NUM:
+      // Use timer0 for temperature measurement
+      // Interleave temperature interrupt with millies interrupt
+      OCR0B = 128;
+      break;
+  }
+}
 
 #define _CAT(a, ...) a ## __VA_ARGS__
 #define HAL_timer_set_compare(timer, compare) (_CAT(TIMER_OCR_, timer) = compare)
diff --git a/Marlin/src/module/stepper.cpp b/Marlin/src/module/stepper.cpp
index e4e42eda25..6f21d84aaa 100644
--- a/Marlin/src/module/stepper.cpp
+++ b/Marlin/src/module/stepper.cpp
@@ -1993,27 +1993,8 @@ void Stepper::init() {
     E_AXIS_INIT(4);
   #endif
 
-  #ifdef __AVR__
-    // waveform generation = 0100 = CTC
-    SET_WGM(1, CTC_OCRnA);
-
-    // output mode = 00 (disconnected)
-    SET_COMA(1, NORMAL);
-
-    // Set the timer pre-scaler
-    // Generally we use a divider of 8, resulting in a 2MHz timer
-    // frequency on a 16MHz MCU. If you are going to change this, be
-    // sure to regenerate speed_lookuptable.h with
-    // create_speed_lookuptable.py
-    SET_CS(1, PRESCALER_8);  //  CS 2 = 1/8 prescaler
-
-    // Init Stepper ISR to 122 Hz for quick starting
-    OCR1A = 0x4000;
-    TCNT1 = 0;
-  #else
-    // Init Stepper ISR to 122 Hz for quick starting
-    HAL_timer_start(STEP_TIMER_NUM, 122);
-  #endif
+  // Init Stepper ISR to 122 Hz for quick starting
+  HAL_timer_start(STEP_TIMER_NUM, 122);
 
   ENABLE_STEPPER_DRIVER_INTERRUPT();
 
diff --git a/Marlin/src/module/temperature.cpp b/Marlin/src/module/temperature.cpp
index bb45dcafd3..a195c86e5d 100644
--- a/Marlin/src/module/temperature.cpp
+++ b/Marlin/src/module/temperature.cpp
@@ -1234,14 +1234,7 @@ void Temperature::init() {
     HAL_ANALOG_SELECT(FILWIDTH_PIN);
   #endif
 
-  // todo: HAL: fix abstraction
-  #ifdef __AVR__
-    // Use timer0 for temperature measurement
-    // Interleave temperature interrupt with millies interrupt
-    OCR0B = 128;
-  #else
-    HAL_timer_start(TEMP_TIMER_NUM, TEMP_TIMER_FREQUENCY);
-  #endif
+  HAL_timer_start(TEMP_TIMER_NUM, TEMP_TIMER_FREQUENCY);
   ENABLE_TEMPERATURE_INTERRUPT();
 
   #if HAS_AUTO_FAN_0