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//! Delays
use cast::u32;
use cortex_m::peripheral::syst::SystClkSource;
use cortex_m::peripheral::SYST;
use crate::rcc::Clocks;
use embedded_hal::blocking::delay::{DelayMs, DelayUs};
/// System timer (SysTick) as a delay provider
pub struct Delay {
clocks: Clocks,
syst: SYST,
}
impl Delay {
/// Configures the system timer (SysTick) as a delay provider
pub fn new(mut syst: SYST, clocks: Clocks) -> Self {
syst.set_clock_source(SystClkSource::Core);
Delay { syst, clocks }
}
/// Releases the system timer (SysTick) resource
pub fn free(self) -> SYST {
self.syst
}
}
impl DelayMs<u32> for Delay {
fn delay_ms(&mut self, ms: u32) {
self.delay_us(ms * 1_000);
}
}
impl DelayMs<u16> for Delay {
fn delay_ms(&mut self, ms: u16) {
self.delay_ms(u32(ms));
}
}
impl DelayMs<u8> for Delay {
fn delay_ms(&mut self, ms: u8) {
self.delay_ms(u32(ms));
}
}
impl DelayUs<u32> for Delay {
fn delay_us(&mut self, us: u32) {
let rvr = us * (self.clocks.sysclk().0 / 1_000_000);
assert!(rvr < (1 << 24));
self.syst.set_reload(rvr);
self.syst.clear_current();
self.syst.enable_counter();
while !self.syst.has_wrapped() {}
self.syst.disable_counter();
}
}
impl DelayUs<u16> for Delay {
fn delay_us(&mut self, us: u16) {
self.delay_us(u32(us))
}
}
impl DelayUs<u8> for Delay {
fn delay_us(&mut self, us: u8) {
self.delay_us(u32(us))
}
}