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va108xx-hal/src/timer.rs

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//! API for the TIM peripherals
//!
//! ## Examples
//!
//! - [MS and second tick implementation](https://egit.irs.uni-stuttgart.de/rust/va108xx-hal/src/branch/main/examples/timer-ticks.rs)
//! - [Cascade feature example](https://egit.irs.uni-stuttgart.de/rust/va108xx-hal/src/branch/main/examples/cascade.rs)
pub use crate::utility::IrqCfg;
use crate::{
clock::{enable_peripheral_clock, PeripheralClocks},
gpio::{
AltFunc1, AltFunc2, AltFunc3, DynPinId, Pin, PinId, PA0, PA1, PA10, PA11, PA12, PA13, PA14,
PA15, PA2, PA24, PA25, PA26, PA27, PA28, PA29, PA3, PA30, PA31, PA4, PA5, PA6, PA7, PA8,
PA9, PB0, PB1, PB10, PB11, PB12, PB13, PB14, PB15, PB16, PB17, PB18, PB19, PB2, PB20, PB21,
PB22, PB23, PB3, PB4, PB5, PB6,
},
pac::{
self, tim0, TIM0, TIM1, TIM10, TIM11, TIM12, TIM13, TIM14, TIM15, TIM16, TIM17, TIM18,
TIM19, TIM2, TIM20, TIM21, TIM22, TIM23, TIM3, TIM4, TIM5, TIM6, TIM7, TIM8, TIM9,
},
prelude::*,
private::Sealed,
time::Hertz,
timer,
utility::unmask_irq,
};
use core::cell::Cell;
use cortex_m::interrupt::Mutex;
use embedded_hal::{
blocking::delay,
timer::{Cancel, CountDown, Periodic},
};
use va108xx::{IRQSEL, SYSCONFIG};
use void::Void;
const IRQ_DST_NONE: u32 = 0xffffffff;
pub static MS_COUNTER: Mutex<Cell<u32>> = Mutex::new(Cell::new(0));
//==================================================================================================
// Defintions
//==================================================================================================
/// Interrupt events
pub enum Event {
/// Timer timed out / count down ended
TimeOut,
}
#[derive(Default, Debug, PartialEq, Eq, Copy, Clone)]
pub struct CascadeCtrl {
/// Enable Cascade 0 signal active as a requirement for counting
pub enb_start_src_csd0: bool,
/// Invert Cascade 0, making it active low
pub inv_csd0: bool,
/// Enable Cascade 1 signal active as a requirement for counting
pub enb_start_src_csd1: bool,
/// Invert Cascade 1, making it active low
pub inv_csd1: bool,
/// Specify required operation if both Cascade 0 and Cascade 1 are active.
/// 0 is a logical AND of both cascade signals, 1 is a logical OR
pub dual_csd_op: bool,
/// Enable trigger mode for Cascade 0. In trigger mode, couting will start with the selected
/// cascade signal active, but once the counter is active, cascade control will be ignored
pub trg_csd0: bool,
/// Trigger mode, identical to [`trg_csd0`](CascadeCtrl) but for Cascade 1
pub trg_csd1: bool,
/// Enable Cascade 2 signal active as a requirement to stop counting. This mode is similar
/// to the REQ_STOP control bit, but signalled by a Cascade source
pub enb_stop_src_csd2: bool,
/// Invert Cascade 2, making it active low
pub inv_csd2: bool,
/// The counter is automatically disabled if the corresponding Cascade 2 level-sensitive input
/// souce is active when the count reaches 0. If the counter is not 0, the cascade control is
/// ignored
pub trg_csd2: bool,
}
#[derive(Debug, PartialEq, Eq)]
pub enum CascadeSel {
Csd0 = 0,
Csd1 = 1,
Csd2 = 2,
}
/// The numbers are the base numbers for bundles like PORTA, PORTB or TIM
#[derive(Debug, PartialEq, Eq)]
pub enum CascadeSource {
PortABase = 0,
PortBBase = 32,
TimBase = 64,
RamSbe = 96,
RamMbe = 97,
RomSbe = 98,
RomMbe = 99,
Txev = 100,
ClockDividerBase = 120,
}
#[derive(Debug, PartialEq, Eq)]
pub enum TimerErrors {
Canceled,
/// Invalid input for Cascade source
InvalidCsdSourceInput,
}
//==================================================================================================
// Valid TIM and PIN combinations
//==================================================================================================
pub trait TimPin {
const DYN: DynPinId;
}
pub trait ValidTim {
// TIM ID ranging from 0 to 23 for 24 TIM peripherals
const TIM_ID: u8;
}
macro_rules! tim_marker {
($TIMX:ident, $ID:expr) => {
impl ValidTim for $TIMX {
const TIM_ID: u8 = $ID;
}
};
}
tim_marker!(TIM0, 0);
tim_marker!(TIM1, 1);
tim_marker!(TIM2, 2);
tim_marker!(TIM3, 3);
tim_marker!(TIM4, 4);
tim_marker!(TIM5, 5);
tim_marker!(TIM6, 6);
tim_marker!(TIM7, 7);
tim_marker!(TIM8, 8);
tim_marker!(TIM9, 9);
tim_marker!(TIM10, 10);
tim_marker!(TIM11, 11);
tim_marker!(TIM12, 12);
tim_marker!(TIM13, 13);
tim_marker!(TIM14, 14);
tim_marker!(TIM15, 15);
tim_marker!(TIM16, 16);
tim_marker!(TIM17, 17);
tim_marker!(TIM18, 18);
tim_marker!(TIM19, 19);
tim_marker!(TIM20, 20);
tim_marker!(TIM21, 21);
tim_marker!(TIM22, 22);
tim_marker!(TIM23, 23);
pub trait ValidTimAndPin<PIN: TimPin, TIM: ValidTim>: Sealed {}
macro_rules! pin_and_tim {
($PAX:ident, $ALTFUNC:ident, $ID:expr, $TIMX:ident) => {
impl TimPin for Pin<$PAX, $ALTFUNC>
where
$PAX: PinId,
{
const DYN: DynPinId = $PAX::DYN;
}
impl<PIN: TimPin, TIM: ValidTim> ValidTimAndPin<PIN, TIM> for (Pin<$PAX, $ALTFUNC>, $TIMX)
where
Pin<$PAX, $ALTFUNC>: TimPin,
$PAX: PinId,
{
}
impl Sealed for (Pin<$PAX, $ALTFUNC>, $TIMX) {}
};
}
pin_and_tim!(PA31, AltFunc2, 23, TIM23);
pin_and_tim!(PA30, AltFunc2, 22, TIM22);
pin_and_tim!(PA29, AltFunc2, 21, TIM21);
pin_and_tim!(PA28, AltFunc2, 20, TIM20);
pin_and_tim!(PA27, AltFunc2, 19, TIM19);
pin_and_tim!(PA26, AltFunc2, 18, TIM18);
pin_and_tim!(PA25, AltFunc2, 17, TIM17);
pin_and_tim!(PA24, AltFunc2, 16, TIM16);
pin_and_tim!(PA15, AltFunc1, 15, TIM15);
pin_and_tim!(PA14, AltFunc1, 14, TIM14);
pin_and_tim!(PA13, AltFunc1, 13, TIM13);
pin_and_tim!(PA12, AltFunc1, 12, TIM12);
pin_and_tim!(PA11, AltFunc1, 11, TIM11);
pin_and_tim!(PA10, AltFunc1, 10, TIM10);
pin_and_tim!(PA9, AltFunc1, 9, TIM9);
pin_and_tim!(PA8, AltFunc1, 8, TIM8);
pin_and_tim!(PA7, AltFunc1, 7, TIM7);
pin_and_tim!(PA6, AltFunc1, 6, TIM6);
pin_and_tim!(PA5, AltFunc1, 5, TIM5);
pin_and_tim!(PA4, AltFunc1, 4, TIM4);
pin_and_tim!(PA3, AltFunc1, 3, TIM3);
pin_and_tim!(PA2, AltFunc1, 2, TIM2);
pin_and_tim!(PA1, AltFunc1, 1, TIM1);
pin_and_tim!(PA0, AltFunc1, 0, TIM0);
pin_and_tim!(PB23, AltFunc3, 23, TIM23);
pin_and_tim!(PB22, AltFunc3, 22, TIM22);
pin_and_tim!(PB21, AltFunc3, 21, TIM21);
pin_and_tim!(PB20, AltFunc3, 20, TIM20);
pin_and_tim!(PB19, AltFunc3, 19, TIM19);
pin_and_tim!(PB18, AltFunc3, 18, TIM18);
pin_and_tim!(PB17, AltFunc3, 17, TIM17);
pin_and_tim!(PB16, AltFunc3, 16, TIM16);
pin_and_tim!(PB15, AltFunc3, 15, TIM15);
pin_and_tim!(PB14, AltFunc3, 14, TIM14);
pin_and_tim!(PB13, AltFunc3, 13, TIM13);
pin_and_tim!(PB12, AltFunc3, 12, TIM12);
pin_and_tim!(PB11, AltFunc3, 11, TIM11);
pin_and_tim!(PB10, AltFunc3, 10, TIM10);
pin_and_tim!(PB6, AltFunc3, 6, TIM6);
pin_and_tim!(PB5, AltFunc3, 5, TIM5);
pin_and_tim!(PB4, AltFunc3, 4, TIM4);
pin_and_tim!(PB3, AltFunc3, 3, TIM3);
pin_and_tim!(PB2, AltFunc3, 2, TIM2);
pin_and_tim!(PB1, AltFunc3, 1, TIM1);
pin_and_tim!(PB0, AltFunc3, 0, TIM0);
//==================================================================================================
// Register Interface for TIM registers and TIM pins
//==================================================================================================
pub type TimRegBlock = tim0::RegisterBlock;
/// Register interface.
///
/// This interface provides valid TIM pins a way to access their corresponding TIM
/// registers
///
/// # Safety
///
/// Users should only implement the [`tim_id`] function. No default function
/// implementations should be overridden. The implementing type must also have
/// "control" over the corresponding pin ID, i.e. it must guarantee that a each
/// pin ID is a singleton.
pub(super) unsafe trait TimRegInterface {
fn tim_id(&self) -> u8;
const PORT_BASE: *const tim0::RegisterBlock = TIM0::ptr() as *const _;
/// All 24 TIM blocks are identical. This helper functions returns the correct
/// memory mapped peripheral depending on the TIM ID.
#[inline(always)]
fn reg(&self) -> &TimRegBlock {
unsafe { &*Self::PORT_BASE.offset(self.tim_id() as isize) }
}
#[inline(always)]
fn mask_32(&self) -> u32 {
1 << self.tim_id()
}
/// Clear the reset bit of the TIM, holding it in reset
///
/// # Safety
///
/// Only the bit related to the corresponding TIM peripheral is modified
#[inline]
fn clear_tim_reset_bit(&self) {
unsafe {
va108xx::Peripherals::steal()
.SYSCONFIG
.tim_reset
.modify(|r, w| w.bits(r.bits() & !self.mask_32()))
}
}
#[inline]
fn set_tim_reset_bit(&self) {
unsafe {
va108xx::Peripherals::steal()
.SYSCONFIG
.tim_reset
.modify(|r, w| w.bits(r.bits() | self.mask_32()))
}
}
}
/// Register interface.
///
/// This interface provides an interface for TIM pins to access their corresponding
/// configuration
///
/// # Safety
///
/// Users should only implement the [`pin_id`] function. No default function
/// implementations should be overridden. The implementing type must also have
/// "control" over the corresponding pin ID, i.e. it must guarantee that a each
/// pin ID is a singleton.
pub(super) unsafe trait TimPinInterface {
fn pin_id(&self) -> DynPinId;
}
/// Provide a safe register interface for [`ValidTimAndPin`]s
///
/// This `struct` takes ownership of a [`ValidTimAndPin`] and provides an API to
/// access the corresponding registers.
pub(super) struct TimAndPinRegister<PIN: TimPin, TIM: ValidTim> {
pin: PIN,
tim: TIM,
}
pub(super) struct TimRegister<TIM: ValidTim> {
tim: TIM,
}
impl<TIM: ValidTim> TimRegister<TIM> {
#[inline]
pub(super) unsafe fn new(tim: TIM) -> Self {
TimRegister { tim }
}
pub(super) fn release(self) -> TIM {
self.tim
}
}
unsafe impl<TIM: ValidTim> TimRegInterface for TimRegister<TIM> {
fn tim_id(&self) -> u8 {
TIM::TIM_ID
}
}
impl<PIN: TimPin, TIM: ValidTim> TimAndPinRegister<PIN, TIM>
where
(PIN, TIM): ValidTimAndPin<PIN, TIM>,
{
#[inline]
pub(super) unsafe fn new(pin: PIN, tim: TIM) -> Self {
TimAndPinRegister { pin, tim }
}
pub(super) fn release(self) -> (PIN, TIM) {
(self.pin, self.tim)
}
}
unsafe impl<PIN: TimPin, TIM: ValidTim> TimRegInterface for TimAndPinRegister<PIN, TIM> {
#[inline(always)]
fn tim_id(&self) -> u8 {
TIM::TIM_ID
}
}
unsafe impl<PIN: TimPin, TIM: ValidTim> TimPinInterface for TimAndPinRegister<PIN, TIM> {
#[inline(always)]
fn pin_id(&self) -> DynPinId {
PIN::DYN
}
}
pub(super) struct TimDynRegister {
tim_id: u8,
pin_id: DynPinId,
}
impl<PIN: TimPin, TIM: ValidTim> From<TimAndPinRegister<PIN, TIM>> for TimDynRegister {
fn from(_reg: TimAndPinRegister<PIN, TIM>) -> Self {
Self {
tim_id: TIM::TIM_ID,
pin_id: PIN::DYN,
}
}
}
unsafe impl TimRegInterface for TimDynRegister {
#[inline(always)]
fn tim_id(&self) -> u8 {
self.tim_id
}
}
unsafe impl TimPinInterface for TimDynRegister {
#[inline(always)]
fn pin_id(&self) -> DynPinId {
self.pin_id
}
}
//==================================================================================================
// Timers
//==================================================================================================
/// Hardware timers
pub struct CountDownTimer<TIM: ValidTim> {
tim: TimRegister<TIM>,
curr_freq: Hertz,
irq_cfg: Option<IrqCfg>,
sys_clk: Hertz,
rst_val: u32,
last_cnt: u32,
listening: bool,
}
fn enable_tim_clk(syscfg: &mut SYSCONFIG, idx: u8) {
syscfg
.tim_clk_enable
.modify(|r, w| unsafe { w.bits(r.bits() | (1 << idx)) });
}
unsafe impl<TIM: ValidTim> TimRegInterface for CountDownTimer<TIM> {
fn tim_id(&self) -> u8 {
TIM::TIM_ID
}
}
macro_rules! csd_sel {
($func_name:ident, $csd_reg:ident) => {
/// Configure the Cascade sources
pub fn $func_name(
&mut self,
src: CascadeSource,
id: Option<u8>,
) -> Result<(), TimerErrors> {
let mut id_num = 0;
if let CascadeSource::PortABase
| CascadeSource::PortBBase
| CascadeSource::ClockDividerBase
| CascadeSource::TimBase = src
{
if id.is_none() {
return Err(TimerErrors::InvalidCsdSourceInput);
}
}
if id.is_some() {
id_num = id.unwrap();
}
match src {
CascadeSource::PortABase => {
if id_num > 55 {
return Err(TimerErrors::InvalidCsdSourceInput);
}
self.tim.reg().$csd_reg.write(|w| unsafe {
w.cassel().bits(CascadeSource::PortABase as u8 + id_num)
});
Ok(())
}
CascadeSource::PortBBase => {
if id_num > 23 {
return Err(TimerErrors::InvalidCsdSourceInput);
}
self.tim.reg().$csd_reg.write(|w| unsafe {
w.cassel().bits(CascadeSource::PortBBase as u8 + id_num)
});
Ok(())
}
CascadeSource::TimBase => {
if id_num > 23 {
return Err(TimerErrors::InvalidCsdSourceInput);
}
self.tim.reg().$csd_reg.write(|w| unsafe {
w.cassel().bits(CascadeSource::TimBase as u8 + id_num)
});
Ok(())
}
CascadeSource::ClockDividerBase => {
if id_num > 7 {
return Err(TimerErrors::InvalidCsdSourceInput);
}
self.tim.reg().cascade0.write(|w| unsafe {
w.cassel()
.bits(CascadeSource::ClockDividerBase as u8 + id_num)
});
Ok(())
}
_ => {
self.tim
.reg()
.$csd_reg
.write(|w| unsafe { w.cassel().bits(src as u8) });
Ok(())
}
}
}
};
}
impl<TIM: ValidTim> CountDownTimer<TIM> {
/// Configures a TIM peripheral as a periodic count down timer
pub fn new(syscfg: &mut SYSCONFIG, sys_clk: impl Into<Hertz>, tim: TIM) -> Self {
enable_tim_clk(syscfg, TIM::TIM_ID);
let cd_timer = CountDownTimer {
tim: unsafe { TimRegister::new(tim) },
sys_clk: sys_clk.into(),
irq_cfg: None,
rst_val: 0,
curr_freq: 0.hz(),
listening: false,
last_cnt: 0,
};
cd_timer.tim.reg().ctrl.modify(|_, w| w.enable().set_bit());
cd_timer
}
/// Listen for events. Depending on the IRQ configuration, this also activates the IRQ in the
/// IRQSEL peripheral for the provided interrupt and unmasks the interrupt
pub fn listen(
&mut self,
event: Event,
irq_cfg: IrqCfg,
irq_sel: Option<&mut IRQSEL>,
sys_cfg: Option<&mut SYSCONFIG>,
) {
match event {
Event::TimeOut => {
cortex_m::peripheral::NVIC::mask(irq_cfg.irq);
self.irq_cfg = Some(irq_cfg);
if irq_cfg.route {
if let Some(sys_cfg) = sys_cfg {
enable_peripheral_clock(sys_cfg, PeripheralClocks::Irqsel);
}
if let Some(irq_sel) = irq_sel {
irq_sel.tim[TIM::TIM_ID as usize]
.write(|w| unsafe { w.bits(irq_cfg.irq as u32) });
}
}
self.listening = true;
}
}
}
pub fn unlisten(&mut self, event: Event, syscfg: &mut SYSCONFIG, irqsel: &mut IRQSEL) {
match event {
Event::TimeOut => {
enable_peripheral_clock(syscfg, PeripheralClocks::Irqsel);
irqsel.tim[TIM::TIM_ID as usize].write(|w| unsafe { w.bits(IRQ_DST_NONE) });
self.disable_interrupt();
self.listening = false;
}
}
}
#[inline(always)]
pub fn enable_interrupt(&mut self) {
self.tim.reg().ctrl.modify(|_, w| w.irq_enb().set_bit());
}
#[inline(always)]
pub fn disable_interrupt(&mut self) {
self.tim.reg().ctrl.modify(|_, w| w.irq_enb().clear_bit());
}
pub fn release(self, syscfg: &mut SYSCONFIG) -> TIM {
self.tim.reg().ctrl.write(|w| w.enable().clear_bit());
syscfg
.tim_clk_enable
.modify(|r, w| unsafe { w.bits(r.bits() & !(1 << TIM::TIM_ID)) });
self.tim.release()
}
/// Load the count down timer with a timeout but do not start it.
pub fn load(&mut self, timeout: impl Into<Hertz>) {
self.tim.reg().ctrl.modify(|_, w| w.enable().clear_bit());
self.curr_freq = timeout.into();
self.rst_val = self.sys_clk.0 / self.curr_freq.0;
unsafe {
self.tim.reg().rst_value.write(|w| w.bits(self.rst_val));
self.tim.reg().cnt_value.write(|w| w.bits(self.rst_val));
}
}
#[inline(always)]
pub fn enable(&mut self) {
self.tim.reg().ctrl.modify(|_, w| w.enable().set_bit());
if let Some(irq_cfg) = self.irq_cfg {
self.enable_interrupt();
if irq_cfg.enable {
unmask_irq(irq_cfg.irq);
}
}
}
#[inline(always)]
pub fn disable(&mut self) {
self.tim.reg().ctrl.modify(|_, w| w.enable().clear_bit());
}
/// Disable the counter, setting both enable and active bit to 0
pub fn auto_disable(self, enable: bool) -> Self {
if enable {
self.tim
.reg()
.ctrl
.modify(|_, w| w.auto_disable().set_bit());
} else {
self.tim
.reg()
.ctrl
.modify(|_, w| w.auto_disable().clear_bit());
}
self
}
/// This option only applies when the Auto-Disable functionality is 0.
///
/// The active bit is changed to 0 when count reaches 0, but the counter stays
/// enabled. When Auto-Disable is 1, Auto-Deactivate is implied
pub fn auto_deactivate(self, enable: bool) -> Self {
if enable {
self.tim
.reg()
.ctrl
.modify(|_, w| w.auto_deactivate().set_bit());
} else {
self.tim
.reg()
.ctrl
.modify(|_, w| w.auto_deactivate().clear_bit());
}
self
}
/// Configure the cascade parameters
pub fn cascade_control(&mut self, ctrl: CascadeCtrl) {
self.tim.reg().csd_ctrl.write(|w| {
w.csden0().bit(ctrl.enb_start_src_csd0);
w.csdinv0().bit(ctrl.inv_csd0);
w.csden1().bit(ctrl.enb_start_src_csd1);
w.csdinv1().bit(ctrl.inv_csd1);
w.dcasop().bit(ctrl.dual_csd_op);
w.csdtrg0().bit(ctrl.trg_csd0);
w.csdtrg1().bit(ctrl.trg_csd1);
w.csden2().bit(ctrl.enb_stop_src_csd2);
w.csdinv2().bit(ctrl.inv_csd2);
w.csdtrg2().bit(ctrl.trg_csd2)
});
}
csd_sel!(cascade_0_source, cascade0);
csd_sel!(cascade_1_source, cascade1);
csd_sel!(cascade_2_source, cascade2);
pub fn curr_freq(&self) -> Hertz {
self.curr_freq
}
pub fn listening(&self) -> bool {
self.listening
}
}
/// CountDown implementation for TIMx
impl<TIM: ValidTim> CountDown for CountDownTimer<TIM> {
type Time = Hertz;
#[inline]
fn start<T>(&mut self, timeout: T)
where
T: Into<Hertz>,
{
self.load(timeout);
self.enable();
}
/// Return `Ok` if the timer has wrapped. Peripheral will automatically clear the
/// flag and restart the time if configured correctly
fn wait(&mut self) -> nb::Result<(), Void> {
let cnt = self.tim.reg().cnt_value.read().bits();
if (cnt > self.last_cnt) || cnt == 0 {
self.last_cnt = self.rst_val;
Ok(())
} else {
self.last_cnt = cnt;
Err(nb::Error::WouldBlock)
}
}
}
impl<TIM: ValidTim> Periodic for CountDownTimer<TIM> {}
impl<TIM: ValidTim> Cancel for CountDownTimer<TIM> {
type Error = TimerErrors;
fn cancel(&mut self) -> Result<(), Self::Error> {
if !self.tim.reg().ctrl.read().enable().bit_is_set() {
return Err(TimerErrors::Canceled);
}
self.tim.reg().ctrl.write(|w| w.enable().clear_bit());
Ok(())
}
}
/// Delay for microseconds.
///
/// For delays less than 100 us, an assembly delay will be used.
/// For larger delays, the timer peripheral will be used.
/// Please note that the delay using the peripheral might not
/// work properly in debug mode.
impl<TIM: ValidTim> delay::DelayUs<u32> for CountDownTimer<TIM> {
fn delay_us(&mut self, us: u32) {
if us < 100 {
cortex_m::asm::delay(us * (self.sys_clk.0 / 2_000_000));
} else {
// Configuring the peripheral for higher frequencies is unstable
self.start(1000.khz());
// The subtracted value is an empirical value measures by using tests with
// an oscilloscope.
for _ in 0..us - 7 {
nb::block!(self.wait()).unwrap();
}
}
}
}
/// Forwards call to u32 variant of delay
impl<TIM: ValidTim> delay::DelayUs<u16> for CountDownTimer<TIM> {
fn delay_us(&mut self, us: u16) {
self.delay_us(u32::from(us));
}
}
/// Forwards call to u32 variant of delay
impl<TIM: ValidTim> delay::DelayUs<u8> for CountDownTimer<TIM> {
fn delay_us(&mut self, us: u8) {
self.delay_us(u32::from(us));
}
}
impl<TIM: ValidTim> delay::DelayMs<u32> for CountDownTimer<TIM> {
fn delay_ms(&mut self, ms: u32) {
self.start(1000.hz());
for _ in 0..ms {
nb::block!(self.wait()).unwrap();
}
}
}
impl<TIM: ValidTim> delay::DelayMs<u16> for CountDownTimer<TIM> {
fn delay_ms(&mut self, ms: u16) {
self.delay_ms(u32::from(ms));
}
}
impl<TIM: ValidTim> embedded_hal::blocking::delay::DelayMs<u8> for CountDownTimer<TIM> {
fn delay_ms(&mut self, ms: u8) {
self.delay_ms(u32::from(ms));
}
}
// Set up a millisecond timer on TIM0. Please note that you still need to unmask the related IRQ
// and provide an IRQ handler yourself
pub fn set_up_ms_timer<TIM: ValidTim>(
irq_cfg: IrqCfg,
sys_cfg: &mut pac::SYSCONFIG,
irq_sel: Option<&mut pac::IRQSEL>,
sys_clk: impl Into<Hertz>,
tim0: TIM,
) -> CountDownTimer<TIM> {
let mut ms_timer = CountDownTimer::new(sys_cfg, sys_clk, tim0);
ms_timer.listen(timer::Event::TimeOut, irq_cfg, irq_sel, Some(sys_cfg));
ms_timer.start(1000.hz());
ms_timer
}
pub fn set_up_ms_delay_provider<TIM: ValidTim>(
sys_cfg: &mut pac::SYSCONFIG,
sys_clk: impl Into<Hertz>,
tim: TIM,
) -> CountDownTimer<TIM> {
let mut provider = CountDownTimer::new(sys_cfg, sys_clk, tim);
provider.start(1000.hz());
provider
}
/// This function can be called in a specified interrupt handler to increment
/// the MS counter
pub fn default_ms_irq_handler() {
cortex_m::interrupt::free(|cs| {
let mut ms = MS_COUNTER.borrow(cs).get();
ms += 1;
MS_COUNTER.borrow(cs).set(ms);
});
}
/// Get the current MS tick count
pub fn get_ms_ticks() -> u32 {
cortex_m::interrupt::free(|cs| MS_COUNTER.borrow(cs).get())
}
//==================================================================================================
// Delay implementations
//==================================================================================================
pub struct Delay {
cd_tim: CountDownTimer<TIM0>,
}
impl Delay {
pub fn new(tim0: CountDownTimer<TIM0>) -> Self {
Delay { cd_tim: tim0 }
}
}
/// This assumes that the user has already set up a MS tick timer in TIM0 as a system tick
/// with [`set_up_ms_delay_provider`]
impl embedded_hal::blocking::delay::DelayMs<u32> for Delay {
fn delay_ms(&mut self, ms: u32) {
if self.cd_tim.curr_freq() != 1000.hz() || !self.cd_tim.listening() {
return;
}
let start_time = get_ms_ticks();
while get_ms_ticks() - start_time < ms {
cortex_m::asm::nop();
}
}
}
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