Flesh out more stuff, including AVR timer setup

avr/main.c

@@ -0,0 +1,42 @@
+#include <avr/interrupt.h>
+
+#include <tabby/clock.h>
+
+uint16_t timer_counter_intervals[4] = {
+    1953, 977, 61, 31
+};
+
+void setup_internal_clock(tabby_clock_speed speed) {
+    /*
+     * Enable timer interrupt vector
+     */
+    TIMSK = (1 << TOIE1);
+
+    /*
+     * Reset timer counter to zero
+     */
+    TCNT1 = 0;
+
+    /*
+     * Set timer interval
+     */
+    OCR1A = timer_counter_intervals[speed];
+
+    /*
+     * Set timer clock divider to 1/1
+     */
+    TCCR1B = (1 << CS10);
+}
+
+void setup_external_clock() {
+    /*
+     * Disable internal timer interrupts
+     */
+    TCCR1B = 0;
+    OCR1A  = 0;
+    TIMSK  = 0;
+}
+
+int main() {
+    return 0;
+}

include/tabby/clock.h

@@ -1,16 +1,16 @@
 #ifndef _TABBY_CLOCK_H
 #define _TABBY_CLOCK_H
 
-typedef enum tabby_clock_mode {
+typedef enum {
     TABBY_CLOCK_SOURCE_INTERNAL = 0x01,
     TABBY_CLOCK_SOURCE_EXTERNAL = 0x02
-};
+} tabby_clock_mode;
 
-typedef enum tabby_clock_speed {
+typedef enum {
     TABBY_CLOCK_SPEED_8192HZ   = 0x01,
     TABBY_CLOCK_SPEED_16384HZ  = 0x02,
-    TABBY_CLOCK_SPEED_262144HZ = 0x20,
-    TABBY_CLOCK_SPEED_524288HZ = 0x40
-};
+    TABBY_CLOCK_SPEED_262144HZ = 0x03,
+    TABBY_CLOCK_SPEED_524288HZ = 0x04
+} tabby_clock_speed;
 
 #endif /* _TABBY_CLOCK_H */

include/tabby/command.h

@@ -1,10 +1,10 @@
 #ifndef _TABBY_COMMAND_H
 #define _TABBY_COMMAND_H
 
-typedef enum tabby_command {
+typedef enum {
     TABBY_COMMAND_SEND         = 0x01,
     TABBY_COMMAND_CLOCK_SOURCE = 0x02,
     TABBY_COMMAND_CLOCK_SPEED  = 0x03
-};
+} tabby_command;
 
 #endif /* _TABBY_COMMAND_H */