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use cast::{u16, u32};
use cortex_m::peripheral::syst::SystClkSource;
use cortex_m::peripheral::SYST;
use hal::timer::{CountDown, Periodic};
use nb;
use void::Void;
use crate::rcc::{Clocks, Rcc};
use crate::stm32::{TIM2, TIM3, TIM4, TIM5, TIM6, TIM7, TIM9};
use crate::time::Hertz;
pub trait TimerExt<TIM> {
fn timer<T>(self, timeout: T, rcc: &mut Rcc) -> Timer<TIM>
where
T: Into<Hertz>;
}
pub struct Timer<TIM> {
clocks: Clocks,
tim: TIM,
}
impl Timer<SYST> {
pub fn syst<T>(mut syst: SYST, timeout: T, rcc: &mut Rcc) -> Self
where
T: Into<Hertz>,
{
syst.set_clock_source(SystClkSource::Core);
let mut timer = Timer {
tim: syst,
clocks: rcc.clocks,
};
timer.start(timeout);
timer
}
pub fn listen(&mut self) {
self.tim.enable_interrupt()
}
pub fn unlisten(&mut self) {
self.tim.disable_interrupt()
}
}
impl CountDown for Timer<SYST> {
type Time = Hertz;
fn start<T>(&mut self, timeout: T)
where
T: Into<Hertz>,
{
let rvr = self.clocks.sys_clk().0 / timeout.into().0 - 1;
assert!(rvr < (1 << 24));
self.tim.set_reload(rvr);
self.tim.clear_current();
self.tim.enable_counter();
}
fn wait(&mut self) -> nb::Result<(), Void> {
if self.tim.has_wrapped() {
Ok(())
} else {
Err(nb::Error::WouldBlock)
}
}
}
impl TimerExt<SYST> for SYST {
fn timer<T>(self, timeout: T, rcc: &mut Rcc) -> Timer<SYST>
where
T: Into<Hertz>,
{
Timer::syst(self, timeout, rcc)
}
}
impl Periodic for Timer<SYST> {}
macro_rules! timers {
($($TIM:ident: ($tim:ident, $timXen:ident, $timXrst:ident, $apbenr:ident, $apbrstr:ident, $timclk:ident),)+) => {
$(
impl TimerExt<$TIM> for $TIM {
fn timer<T>(self, timeout: T, rcc: &mut Rcc) -> Timer<$TIM>
where
T: Into<Hertz>,
{
Timer::$tim(self, timeout, rcc)
}
}
impl Timer<$TIM> {
pub fn $tim<T>(tim: $TIM, timeout: T, rcc: &mut Rcc) -> Self
where
T: Into<Hertz>,
{
rcc.rb.$apbenr.modify(|_, w| w.$timXen().set_bit());
rcc.rb.$apbrstr.modify(|_, w| w.$timXrst().set_bit());
rcc.rb.$apbrstr.modify(|_, w| w.$timXrst().clear_bit());
let mut timer = Timer {
tim,
clocks: rcc.clocks,
};
timer.start(timeout);
timer
}
pub fn listen(&mut self) {
self.tim.dier.write(|w| w.uie().set_bit());
}
pub fn unlisten(&mut self) {
self.tim.dier.write(|w| w.uie().clear_bit());
}
pub fn clear_irq(&mut self) {
self.tim.sr.write(|w| w.uif().clear_bit());
}
pub fn release(self) -> $TIM {
self.tim.cr1.modify(|_, w| w.cen().clear_bit());
self.tim
}
}
impl CountDown for Timer<$TIM> {
type Time = Hertz;
fn start<T>(&mut self, timeout: T)
where
T: Into<Hertz>,
{
self.tim.cr1.modify(|_, w| w.cen().clear_bit());
self.tim.cnt.reset();
let freq = timeout.into().0;
let ticks = self.clocks.$timclk().0 / freq;
let psc = u16((ticks - 1) / (1 << 16)).unwrap();
self.tim.psc.write(|w| unsafe { w.psc().bits(psc) });
self.tim.arr.write(|w| unsafe { w.bits(ticks / u32(psc + 1)) });
self.tim.cr1.modify(|_, w| w.urs().set_bit());
self.tim.cr1.modify(|_, w| w.cen().set_bit());
}
fn wait(&mut self) -> nb::Result<(), Void> {
if self.tim.sr.read().uif().bit_is_clear() {
Err(nb::Error::WouldBlock)
} else {
self.tim.sr.modify(|_, w| w.uif().clear_bit());
Ok(())
}
}
}
impl Periodic for Timer<$TIM> {}
)+
}
}
timers! {
TIM2: (tim2, tim2en, tim2rst, apb1enr, apb1rstr, apb1_tim_clk),
TIM3: (tim3, tim3en, tim3rst, apb1enr, apb1rstr, apb1_tim_clk),
TIM4: (tim4, tim4en, tim4rst, apb1enr, apb1rstr, apb1_tim_clk),
TIM5: (tim5, tim5en, tim5rst, apb1enr, apb1rstr, apb1_tim_clk),
TIM6: (tim6, tim6en, tim6rst, apb1enr, apb1rstr, apb1_tim_clk),
TIM7: (tim7, tim7en, tim7rst, apb1enr, apb1rstr, apb1_tim_clk),
TIM9: (tim9, tim9en, tim9rst, apb2enr, apb2rstr, apb2_tim_clk),
}