From 4f6ea165153809b35541700a80e44789d186609c Mon Sep 17 00:00:00 2001
From: Alex Voinea <voinea.dragos.alexandru@gmail.com>
Date: Mon, 20 Sep 2021 19:01:08 +0200
Subject: [PATCH] Functional USB reset

---
 src/hal/avr/cpu.cpp | 17 ++++++++++++++++
 src/hal/cpu.h       |  3 +++
 src/hal/watchdog.h  |  4 ++++
 src/main.cpp        | 47 +++++++++++++++++++++++++--------------------
 4 files changed, 50 insertions(+), 21 deletions(-)

diff --git a/src/hal/avr/cpu.cpp b/src/hal/avr/cpu.cpp
index 7bef056..db9d93f 100644
--- a/src/hal/avr/cpu.cpp
+++ b/src/hal/avr/cpu.cpp
@@ -2,9 +2,17 @@
 #include <avr/interrupt.h>
 #include "../watchdog.h"
 
+#include "lufa_config.h"
+#include "Descriptors.h"
+#include "lufa/LUFA/Drivers/USB/USB.h"
+
+#include "../usart.h"
+
 namespace hal {
 namespace cpu {
 
+bool resetPending = false;
+
 void Init() {
 }
 
@@ -15,5 +23,14 @@ void Reset() {
         ; //endless loop while waiting for the watchdog to reset
 }
 
+void Step() {
+    if (resetPending) {
+        hal::usart::usart1.puts("resetPending\n");
+        USB_Detach();
+        for (;;)
+            ; //endless loop while waiting for the watchdog to reset
+    }
+}
+
 } // namespace CPU
 } // namespace hal
diff --git a/src/hal/cpu.h b/src/hal/cpu.h
index ace6a9e..bdf0472 100644
--- a/src/hal/cpu.h
+++ b/src/hal/cpu.h
@@ -10,9 +10,12 @@ namespace cpu {
 #define F_CPU (16000000ul)
 #endif
 
+extern bool resetPending;
+
 /// CPU init routines (not really necessary for the AVR)
 void Init();
 void Reset();
+void Step();
 
 } // namespace cpu
 } // namespace hal
diff --git a/src/hal/watchdog.h b/src/hal/watchdog.h
index a560c14..2a2459e 100644
--- a/src/hal/watchdog.h
+++ b/src/hal/watchdog.h
@@ -37,8 +37,12 @@ public:
         uint8_t prescalerBits = 0;
         uint32_t ticks = 1;
         switch (timeout) {
+        case 250:
+            prescalerBits = 4;
+            break;
         case 8000:
             prescalerBits = 9;
+            break;
         }
 
         configuration config = { prescalerBits, static_cast<uint16_t>(ticks - 1) };
diff --git a/src/main.cpp b/src/main.cpp
index 9cbf362..476c15e 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -100,10 +100,10 @@ void EVENT_USB_Device_ConfigurationChanged(void) {
     ConfigSuccess &= CDC_Device_ConfigureEndpoints(&VirtualSerial_CDC_Interface);
 
     // LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
-    char str1[] = "ready\n";
-    char str0[] = "error\n";
-    hal::usart::usart1.puts("EVENT_USB_Device_ConfigurationChanged:");
-    hal::usart::usart1.puts(ConfigSuccess ? str1 : str0);
+    // char str1[] = "ready\n";
+    // char str0[] = "error\n";
+    // hal::usart::usart1.puts("EVENT_USB_Device_ConfigurationChanged:");
+    // hal::usart::usart1.puts(ConfigSuccess ? str1 : str0);
 }
 
 /** Event handler for the library USB Control Request reception event. */
@@ -118,27 +118,28 @@ void EVENT_USB_Device_ControlRequest(void) {
  *  \param[in] CDCInterfaceInfo  Pointer to the CDC class interface configuration structure being referenced
  */
 void EVENT_CDC_Device_ControLineStateChanged(USB_ClassInfo_CDC_Device_t *const CDCInterfaceInfo) {
-    /* You can get changes to the virtual CDC lines in this callback; a common
-	   use-case is to use the Data Terminal Ready (DTR) flag to enable and
-	   disable CDC communications in your application when set to avoid the
-	   application blocking while waiting for a host to become ready and read
-	   in the pending data from the USB endpoints.
-	*/
-    hal::usart::usart1.puts("EVENT_CDC_Device_ControLineStateChanged ");
-    bool HostReady = (CDCInterfaceInfo->State.ControlLineStates.HostToDevice & CDC_CONTROL_LINE_OUT_DTR) != 0;
-    char str[50];
-    sprintf_P(str, PSTR("DTR:%hu\n"), HostReady);
-    hal::usart::usart1.puts(str);
+    // Printing to serial from here will make Windows commit suicide when opening the port
+
+    // hal::usart::usart1.puts("EVENT_CDC_Device_ControLineStateChanged ");
+    // bool HostReady = (CDCInterfaceInfo->State.ControlLineStates.HostToDevice & CDC_CONTROL_LINE_OUT_DTR) != 0;
+    // char str[50];
+    // sprintf_P(str, PSTR("DTR:%hu\n"), HostReady);
+    // hal::usart::usart1.puts(str);
 }
 
 void EVENT_CDC_Device_LineEncodingChanged(USB_ClassInfo_CDC_Device_t *const CDCInterfaceInfo) {
-    hal::usart::usart1.puts("EVENT_CDC_Device_LineEncodingChanged ");
-    char str[50];
-    sprintf_P(str, PSTR("baud:%lu\n"), CDCInterfaceInfo->State.LineEncoding.BaudRateBPS);
-    hal::usart::usart1.puts(str);
+    // Printing to serial from here will make Windows commit suicide when opening the port
+
+    // hal::usart::usart1.puts("EVENT_CDC_Device_LineEncodingChanged ");
+    // char str[50];
+    // sprintf_P(str, PSTR("baud:%lu\n"), CDCInterfaceInfo->State.LineEncoding.BaudRateBPS);
+    // hal::usart::usart1.puts(str);
+    
     if (CDCInterfaceInfo->State.LineEncoding.BaudRateBPS == 1200) {
-        *(uint16_t *)0x0800U = 0x7777;
-        hal::cpu::Reset();
+        // *(uint16_t *)0x0800U = 0x7777; //old bootloader?
+        *(uint16_t *)(RAMEND-1) = 0x7777;
+        hal::cpu::resetPending = true;
+        hal::watchdog::Enable(hal::watchdog::configuration::compute(250));
     }
 }
 }
@@ -251,6 +252,8 @@ void setup() {
 
     USB_Init();
 
+    _delay_ms(100);
+
     /// Turn off all leds
     for (uint8_t i = 0; i < config::toolCount; i++) {
         ml::leds.SetMode(i, ml::Color::green, ml::Mode::off);
@@ -477,7 +480,9 @@ void loop() {
     ms::selector.Step();
     mui::userInput.Step();
     currentCommand->Step();
+    hal::cpu::Step();
 
+    CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
     CDC_Device_USBTask(&VirtualSerial_CDC_Interface);
     USB_USBTask();