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use cortex_m::peripheral::DWT;
#[derive(PartialEq, PartialOrd, Clone, Copy)]
pub struct Bps(pub u32);
#[derive(PartialEq, PartialOrd, Clone, Copy)]
pub struct Hertz(pub u32);
#[derive(PartialEq, PartialOrd, Clone, Copy)]
pub struct MicroSeconds(pub u32);
pub trait U32Ext {
fn bps(self) -> Bps;
fn hz(self) -> Hertz;
fn khz(self) -> Hertz;
fn mhz(self) -> Hertz;
fn us(self) -> MicroSeconds;
fn ms(self) -> MicroSeconds;
}
pub trait MonoTimerExt {
fn monotonic<T>(self, sys_clk: T) -> MonoTimer
where
T: Into<Hertz>;
}
impl U32Ext for u32 {
fn bps(self) -> Bps {
Bps(self)
}
fn hz(self) -> Hertz {
Hertz(self)
}
fn khz(self) -> Hertz {
Hertz(self * 1_000)
}
fn mhz(self) -> Hertz {
Hertz(self * 1_000_000)
}
fn ms(self) -> MicroSeconds {
MicroSeconds(self * 1_000)
}
fn us(self) -> MicroSeconds {
MicroSeconds(self)
}
}
impl Into<MicroSeconds> for Hertz {
fn into(self) -> MicroSeconds {
let freq = self.0;
assert!(freq != 0 && freq <= 1_000_000);
MicroSeconds(1_000_000 / freq)
}
}
impl Into<Hertz> for MicroSeconds {
fn into(self) -> Hertz {
let period = self.0;
assert!(period != 0 && period <= 1_000_000);
Hertz(1_000_000 / period)
}
}
#[derive(Clone, Copy)]
pub struct MonoTimer {
frequency: Hertz,
}
impl MonoTimer {
pub fn new<T>(mut dwt: DWT, sys_clk: T) -> Self
where
T: Into<Hertz>,
{
dwt.enable_cycle_counter();
drop(dwt);
MonoTimer {
frequency: sys_clk.into(),
}
}
pub fn frequency(&self) -> Hertz {
self.frequency
}
pub fn now(&self) -> Instant {
Instant {
now: DWT::get_cycle_count(),
}
}
}
impl MonoTimerExt for DWT {
fn monotonic<T>(self, sys_clk: T) -> MonoTimer
where
T: Into<Hertz>,
{
MonoTimer::new(self, sys_clk)
}
}
#[derive(Clone, Copy)]
pub struct Instant {
now: u32,
}
impl Instant {
pub fn elapsed(&self) -> u32 {
DWT::get_cycle_count().wrapping_sub(self.now)
}
}