use cast::u32;
use cortex_m::peripheral::syst::SystClkSource;
use cortex_m::peripheral::SYST;
use crate::hal::blocking::delay::{DelayMs, DelayUs};
use crate::rcc::Clocks;
pub struct Delay {
clocks: Clocks,
syst: SYST,
}
impl Delay {
pub fn new(mut syst: SYST, clocks: Clocks) -> Self {
syst.set_clock_source(SystClkSource::Core);
Delay { clocks, syst }
}
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) {
const MAX_RVR: u32 = 0x00FF_FFFF;
let mut total_rvr = us * (self.clocks.sysclk().0 / 1_000_000);
while total_rvr != 0 {
let current_rvr = if total_rvr <= MAX_RVR {
total_rvr
} else {
MAX_RVR
};
self.syst.set_reload(current_rvr);
self.syst.clear_current();
self.syst.enable_counter();
total_rvr -= current_rvr;
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))
}
}