OctoClock bugfixes

* Bumped compatibility version to 3
* firmware: Ethernet, clkdist bugfixes
* lib: fixed invalid rev detection

2 files changed, 131 insertions, 23 deletions

diff --git a/firmware/octoclock/octoclock_r4/CMakeLists.txt b/firmware/octoclock/octoclock_r4/CMakeLists.txt
index c3559d8d4..9223721c8 100644
--- a/firmware/octoclock/octoclock_r4/CMakeLists.txt
+++ b/firmware/octoclock/octoclock_r4/CMakeLists.txt
@@ -43,7 +43,7 @@ add_custom_target(
 )
 add_custom_target(
     upload_r4
-    ${AVRDUDE} -p atmega128 -c ${PROGRAMMER} -P usb -U efuse:w:0xFF:m -U hfuse:w:0x81:m -U lfuse:w:0xFF:m -U flash:w:octoclock_r4_fw.hex:i
+    ${AVRDUDE} -p atmega128 -c ${PROGRAMMER} -P usb -U efuse:w:0xFF:m -U hfuse:w:0x81:m -U lfuse:w:0xEF:m -U flash:w:octoclock_r4_fw.hex:i
     WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
     DEPENDS octoclock_r4_fw_hex
     COMMENT "Uploading OctoClock firmware to device with ${PROGRAMMER}"
diff --git a/firmware/octoclock/octoclock_r4/octoclock_r4_main.c b/firmware/octoclock/octoclock_r4/octoclock_r4_main.c
index 5e8e6d09b..b1df34195 100644
--- a/firmware/octoclock/octoclock_r4/octoclock_r4_main.c
+++ b/firmware/octoclock/octoclock_r4/octoclock_r4_main.c
@@ -36,7 +36,7 @@
  * JTAGEN    = [X]
  * SPIEN     = [X]
  * EESAVE    = [X]
- * BOOTSZ    = 4096W_F000
+ * BOOTSZ    = 4095W_F000
  * BOOTRST   = [ ]
  * CKOPT     = [X]
  * BODLEVEL  = 2V7
@@ -49,57 +49,165 @@
  *
  */
 
+#include <stdlib.h>
 #include <string.h>
 #include <stdint.h>
 #include <stdbool.h>
 
 #include <avr/eeprom.h>
+#include <avr/interrupt.h>
 #include <avr/io.h>
 
+#include <avrlibdefs.h>
 #include <octoclock.h>
-#include <clkdist.h>
 #include <debug.h>
+#include <clkdist.h>
 #include <state.h>
 #include <network.h>
 #include <usart.h>
-#include <gpsdo.h>
-#include <net/enc28j60.h>
 #include <net/udp_handlers.h>
 
+/*
+ * Timer 3 (16-bit)
+ *  * Set input capture trigger to rising edge
+ *  * Set prescaler to 1
+ *  * Enable overflow interrupt
+ *  * Set timer to 0
+ */
+#define TIMER3_INIT() TCCR3B = (1 << ICES3) | (1 << CS30); \
+                      ETIMSK |= (1 << TOIE3); \
+                      TCNT3 = 0; \
+                      ICR3 = 0;
+
+/*
+ * We use TIMER3 as a watchdog timer for external reference
+ * detection. Once a signal is detected, we allow for five
+ * timer overflows (~26 ms) without another signal before
+ * deciding that there is no external reference connected.
+ */
+#define EXT_REF_TIMEOUT 5
+
+static volatile uint16_t num_overflows = 0;
+static uint16_t current_num_overflows = 0;
+static uint16_t prev_num_overflows = 0;
+static uint16_t current_ICR3 = 0;
+static uint16_t prev_ICR3 = 0;
+static ref_t        prev_ref           = NO_REF;
+static switch_pos_t prev_switch_pos    = PREFER_EXTERNAL;
+bool top = false;
+
+ISR(TIMER3_OVF_vect){
+    num_overflows++;
+}
+
 /*******************************************************************************
 *   Main Routine
 *******************************************************************************/
 
 int main(void){
 
-    asm("cli");
+    /*
+     * Initializations
+     */
+    cli();
 
+    // Make sure interrupts belong to us
+    MCUCR = (1<<IVCE);
+    MCUCR = 0;
+
+    // Initialize global variables
+    g_ext_ref_present = false;
+    g_gps_present = false;
+    g_switch_pos = PREFER_INTERNAL;
+    g_ref = NO_REF;
+
+    // Atmega128
     setup_atmel_io_ports();
-    network_init();
 
-    #ifndef DEBUG
-    asm("sei");
-    #endif
+    // Reset ClkDist chip
+    reset_TI_CDCE18005();
 
-    init_udp_listeners();
-    register_udp_listener(OCTOCLOCK_UDP_CTRL_PORT, handle_udp_ctrl_packet);
+    // GPSDO communication
+    usart_init();
+
+    // Ethernet stack
+    network_init();
+    register_udp_listener(OCTOCLOCK_UDP_CTRL_PORT,  handle_udp_ctrl_packet);
     register_udp_listener(OCTOCLOCK_UDP_GPSDO_PORT, handle_udp_gpsdo_packet);
 
-    DEBUG_INIT(); // Does nothing when not in debug mode
-    DEBUG_LOG(" "); //Force a newline between runs
-    usart_init();
+    // Timers
+    TIMER1_INIT(); // Network
+    TIMER3_INIT(); // External reference check
+
+    // Debug (does nothing when not in debug mode)
+    DEBUG_INIT();
+    DEBUG_LOG(" "); // Force a newline between runs
+
+    leds_off();
+
+    sei();
+
+    // Check if GPS present (should only need to happen once)
+    g_gps_present = (PIND & (1<<DDD4));
+
+    // State of previous iteration
+    prev_ref           = NO_REF;
+    prev_switch_pos    = PREFER_EXTERNAL;
+    cli();
+    prev_ICR3          = ICR3;
+    sei();
+    prev_num_overflows = 0;
+
+    /*
+     * Main loop
+     */
+    while(true){
+        // Check switch position
+        g_switch_pos = (PINC & (1<<DDC1)) ? PREFER_EXTERNAL : PREFER_INTERNAL;
+
+        /*
+         * Check input capture pin for external reference detection.
+         *
+         * 16-bit reads could be corrupted during an interrupt, so
+         * disable interrupts for safety.
+         */
+        cli();
+        current_ICR3          = ICR3;
+        current_num_overflows = num_overflows;
+        sei();
+
+        // Signal detected, reset timer
+        if(current_ICR3 != prev_ICR3){
+            cli();
+            TCNT3 = 0;
+            num_overflows = 0;
+            sei();
+            g_ext_ref_present = true;
+        }
+
+        // Timeout, no external reference detected
+        if(current_num_overflows >= EXT_REF_TIMEOUT){
+            g_ext_ref_present = false;
+        }
 
-    //Set initial ClkDist and front panel settings
-    led(Middle,true);
-    setup_TI_CDCE18005(Primary_GPS);    // 10 MHz from Internal Source
+        // Determine and set reference based on state
+        if(!g_gps_present && !g_ext_ref_present)     g_ref = NO_REF;
+        else if(g_gps_present && !g_ext_ref_present) g_ref = INTERNAL;
+        else if(!g_gps_present && g_ext_ref_present) g_ref = EXTERNAL;
+        else g_ref = (g_switch_pos == PREFER_INTERNAL) ? INTERNAL : EXTERNAL;
 
-    led(Top,true);
-    PORTA |= (1<<PA6);    // PPS from Internal source
+        if((g_ref != prev_ref) || (g_switch_pos != prev_switch_pos)){
+            if(g_switch_pos == PREFER_INTERNAL) prefer_internal();
+            else prefer_external();
+        }
 
-    TIMER0_INIT();
-    TIMER1_INIT();
+        // Record this iteration's state
+        prev_ref           = g_ref;
+        prev_switch_pos    = g_switch_pos;
+        prev_ICR3          = current_ICR3;
+        prev_num_overflows = current_num_overflows;
 
-    while(true) {
+        // Handle incoming Ethernet packets
         network_check();
     }
 }