sw: add OBI timer test

Author: ezelioli

sw/obi_timer_test.c

@@ -0,0 +1,48 @@
+#include "uart.h"
+#include "print.h"
+#include "obi_timer.h"
+#include "util.h"
+
+#define PRINT_TIMER_IRQ
+
+int timer_count = 0;
+
+// default interrupt handler override
+// count timer interrupts and print irq information
+// note: performing slow operations such as
+// printing through UART inside interrupt service
+// routines is not recommended. Only use for debug
+// or testing.
+void croc_interrupt_handler (uint32_t cause) {
+    if (cause == IRQ_OBI_TIMER) {
+        obi_timer_clear_expired();
+        timer_count += 1;
+        #ifdef PRINT_TIMER_IRQ
+        printf("Timer\n");
+        #endif
+    }
+}
+
+int main() {
+
+    // setup the uart peripheral
+    uart_init();
+
+    // set periodic timer
+    // note: give enough time for printing
+    obi_timer_set(20000);
+
+    // enable timer interrupt
+    set_interrupt_enable(1, IRQ_OBI_TIMER);
+    set_global_irq_enable(1);
+
+    while(timer_count < 10) wfi();
+
+    // disable the timer
+    obi_timer_set_enable(0);
+
+    // wait until uart has finished sending
+    uart_write_flush();
+
+    return 0;
+}