qmk_firmware/tmk_core/common/chibios/timer.c

41 lines
943 B
C

#include "ch.h"
#include "timer.h"
static systime_t last_systime = 0;
static systime_t overflow = 0;
static uint32_t current_time_ms = 0;
void timer_init(void) {
timer_clear();
}
void timer_clear(void) {
last_systime = chVTGetSystemTime();
overflow = 0;
current_time_ms = 0;
}
uint16_t timer_read(void) {
return (uint16_t)timer_read32();
}
uint32_t timer_read32(void) {
// Note: We assume that the timer update is called at least once betweeen every wrap around of the system time
systime_t current_systime = chVTGetSystemTime();
systime_t elapsed = current_systime - last_systime + overflow;
uint32_t elapsed_ms = ST2MS(elapsed);
current_time_ms += elapsed_ms;
overflow = elapsed - MS2ST(elapsed_ms);
last_systime = current_systime;
return current_time_ms;
}
uint16_t timer_elapsed(uint16_t last) {
return timer_read() - last;
}
uint32_t timer_elapsed32(uint32_t last) {
return timer_read32() - last;
}