//specify delay in us (max 1000)
// TODO: if larger than tick
void delay_us(unsigned int nCount)
{
u32 sys_tk = systick_get_value();
sys_tk -= (nCount-1) * 72;
for(;systick_get_value() > sys_tk;);
}
uint8_t tick_expire_us(uint32_t *last_tick, uint32_t time_us)
{
uint32_t tickus, end;
time_us *= 72;
end = systick_get_value();
tickus = tick_delta_time_tick(end, *last_tick);
if (tickus < time_us) return 0;
*last_tick = systick_get_value();
return 1;
}
void tick_wait_us(uint32_t wait_us)
{
uint32_t start;
start = systick_get_value();
while (tick_expire_us(&start, wait_us) == 0);
}
uint64_t time_get_ticks() {
uint64_t result;
// keep calculating result until it is calculated without a rollover having
// happened
{ CriticalSection cs;
do {
result = (rollovers << 24) | (0xffffff - systick_get_value());
} while(check_rollover());
}
return result;
}
uint64_t time_get_ns() {
uint64_t result;
// keep calculating result until it is calculated without a rollover having
// happened
cm_disable_interrupts();
do {
result = (rollovers << 24) | (0xffffff - systick_get_value());
} while(check_rollover());
cm_enable_interrupts();
return result*125/9;
}
// 1.5 ns step
uint64_t stick_get_us(void)
{
CM_ATOMIC_CONTEXT();
uint32_t rld = systick_get_reload() + 1;
uint64_t ss = (rld-systick_get_value()) * 1000 / rld;
if (nvic_get_pending_irq(NVIC_SYSTICK_IRQ) && (ss < 500)) {
// overflow between atomic and get value?
ss += 1000;
}
return ticks * 1000 + ss;
}
/* external interrupt for drdy pin */
exti_select_source(EXTI5, GPIOB);
exti_set_trigger(EXTI5, EXTI_TRIGGER_RISING);
exti_enable_request(EXTI5);
nvic_set_priority(NVIC_EXTI9_5_IRQ, 0x0f);
nvic_enable_irq(NVIC_EXTI9_5_IRQ);
}
void ms2100_reset_cb( struct spi_transaction * t __attribute__ ((unused)) ) {
// set RESET pin high for at least 100 nsec
// busy wait should not harm
Ms2100Set();
// FIXME, make nanosleep funcion
uint32_t dt_ticks = cpu_ticks_of_nsec(110);
int32_t end_cpu_ticks = systick_get_value() - dt_ticks;
if (end_cpu_ticks < 0)
end_cpu_ticks += systick_get_reload();
while (systick_get_value() > (uint32_t)end_cpu_ticks)
;
Ms2100Reset();
}
void exti9_5_isr(void) {
ms2100.status = MS2100_GOT_EOC;
exti_reset_request(EXTI5);
}
uint32_t tick_get_tick(void )
{
return systick_get_value();
}