pounder_test/src/hardware/timers.rs
2021-02-09 14:37:49 +01:00

380 lines
15 KiB
Rust

///! The sampling timer is used for managing ADC sampling and external reference timestamping.
use super::hal;
use hal::stm32::{
// TIM1 and TIM8 have identical registers.
tim1 as __tim8,
tim2 as __tim2,
// TIM2 and TIM5 have identical registers.
tim2 as __tim5,
tim3 as __tim3,
};
/// The event that should generate an external trigger from the peripheral.
#[allow(dead_code)]
pub enum TriggerGenerator {
Reset = 0b000,
Enable = 0b001,
Update = 0b010,
ComparePulse = 0b011,
Ch1Compare = 0b100,
Ch2Compare = 0b101,
Ch3Compare = 0b110,
Ch4Compare = 0b111,
}
/// Selects the trigger source for the timer peripheral.
#[allow(dead_code)]
pub enum TriggerSource {
Trigger0 = 0,
Trigger1 = 0b01,
Trigger2 = 0b10,
Trigger3 = 0b11,
}
/// Prescalers for externally-supplied reference clocks.
#[allow(dead_code)]
pub enum Prescaler {
Div1 = 0b00,
Div2 = 0b01,
Div4 = 0b10,
Div8 = 0b11,
}
/// Optional slave operation modes of a timer.
#[allow(dead_code)]
pub enum SlaveMode {
Disabled = 0,
Trigger = 0b0110,
}
/// Optional input capture preconditioning filter configurations.
#[allow(dead_code)]
pub enum InputFilter {
Div1N1 = 0b0000,
Div1N8 = 0b0011,
}
macro_rules! timer_channels {
($name:ident, $TY:ident, $size:ty) => {
paste::paste! {
/// The timer used for managing ADC sampling.
pub struct $name {
timer: hal::timer::Timer<hal::stm32::[< $TY >]>,
channels: Option<[< $TY:lower >]::Channels>,
update_event: Option<[< $TY:lower >]::UpdateEvent>,
}
impl $name {
/// Construct the sampling timer.
#[allow(dead_code)]
pub fn new(mut timer: hal::timer::Timer<hal::stm32::[< $TY>]>) -> Self {
timer.pause();
Self {
timer,
// Note(unsafe): Once these channels are taken, we guarantee that we do not
// modify any of the underlying timer channel registers, as ownership of the
// channels is now provided through the associated channel structures. We
// additionally guarantee this can only be called once because there is only
// one Timer2 and this resource takes ownership of it once instantiated.
channels: unsafe { Some([< $TY:lower >]::Channels::new()) },
update_event: unsafe { Some([< $TY:lower >]::UpdateEvent::new()) },
}
}
/// Get the timer capture/compare channels.
#[allow(dead_code)]
pub fn channels(&mut self) -> [< $TY:lower >]::Channels {
self.channels.take().unwrap()
}
/// Get the timer update event.
#[allow(dead_code)]
pub fn update_event(&mut self) -> [< $TY:lower >]::UpdateEvent {
self.update_event.take().unwrap()
}
/// Get the period of the timer.
#[allow(dead_code)]
pub fn get_period(&self) -> $size {
let regs = unsafe { &*hal::stm32::$TY::ptr() };
regs.arr.read().arr().bits()
}
/// Manually set the period of the timer.
#[allow(dead_code)]
pub fn set_period_ticks(&mut self, period: $size) {
let regs = unsafe { &*hal::stm32::$TY::ptr() };
regs.arr.write(|w| w.arr().bits(period));
// Force the new period to take effect immediately.
self.timer.apply_freq();
}
/// Clock the timer from an external source.
///
/// # Note:
/// * Currently, only an external source applied to ETR is supported.
///
/// # Args
/// * `prescaler` - The prescaler to use for the external source.
#[allow(dead_code)]
pub fn set_external_clock(&mut self, prescaler: Prescaler) {
let regs = unsafe { &*hal::stm32::$TY::ptr() };
regs.smcr.modify(|_, w| w.etps().bits(prescaler as u8).ece().set_bit());
// Clear any other prescaler configuration.
regs.psc.write(|w| w.psc().bits(0));
}
/// Start the timer.
#[allow(dead_code)]
pub fn start(&mut self) {
// Force a refresh of the frequency settings.
self.timer.apply_freq();
self.timer.reset_counter();
self.timer.resume();
}
/// Configure the timer peripheral to generate a trigger based on the provided
/// source.
#[allow(dead_code)]
pub fn generate_trigger(&mut self, source: TriggerGenerator) {
let regs = unsafe { &*hal::stm32::$TY::ptr() };
// Note(unsafe) The TriggerGenerator enumeration is specified such that this is
// always in range.
regs.cr2.modify(|_, w| w.mms().bits(source as u8));
}
/// Select a trigger source for the timer peripheral.
#[allow(dead_code)]
pub fn set_trigger_source(&mut self, source: TriggerSource) {
let regs = unsafe { &*hal::stm32::$TY::ptr() };
// Note(unsafe) The TriggerSource enumeration is specified such that this is
// always in range.
regs.smcr.modify(|_, w| unsafe { w.ts().bits(source as u8) } );
}
#[allow(dead_code)]
pub fn set_slave_mode(&mut self, source: TriggerSource, mode: SlaveMode) {
let regs = unsafe { &*hal::stm32::$TY::ptr() };
// Note(unsafe) The TriggerSource and SlaveMode enumerations are specified such
// that they are always in range.
regs.smcr.modify(|_, w| unsafe { w.sms().bits(mode as u8).ts().bits(source as u8) } );
}
}
pub mod [< $TY:lower >] {
use stm32h7xx_hal as hal;
use hal::dma::{traits::TargetAddress, PeripheralToMemory, dma::DMAReq};
use hal::stm32::$TY;
pub struct UpdateEvent {}
impl UpdateEvent {
/// Create a new update event
///
/// Note(unsafe): This is only safe to call once.
#[allow(dead_code)]
pub unsafe fn new() -> Self {
Self {}
}
/// Enable DMA requests upon timer updates.
#[allow(dead_code)]
pub fn listen_dma(&self) {
// Note(unsafe): We perform only atomic operations on the timer registers.
let regs = unsafe { &*<$TY>::ptr() };
regs.dier.modify(|_, w| w.ude().set_bit());
}
/// Trigger a DMA request manually
#[allow(dead_code)]
pub fn trigger(&self) {
let regs = unsafe { &*<$TY>::ptr() };
regs.egr.write(|w| w.ug().set_bit());
}
}
/// The channels representing the timer.
pub struct Channels {
pub ch1: Channel1,
pub ch2: Channel2,
pub ch3: Channel3,
pub ch4: Channel4,
}
impl Channels {
/// Construct a new set of channels.
///
/// Note(unsafe): This is only safe to call once.
#[allow(dead_code)]
pub unsafe fn new() -> Self {
Self {
ch1: Channel1::new(),
ch2: Channel2::new(),
ch3: Channel3::new(),
ch4: Channel4::new(),
}
}
}
timer_channels!(1, $TY, ccmr1, $size);
timer_channels!(2, $TY, ccmr1, $size);
timer_channels!(3, $TY, ccmr2, $size);
timer_channels!(4, $TY, ccmr2, $size);
}
}
};
($index:expr, $TY:ty, $ccmrx:expr, $size:ty) => {
paste::paste! {
pub use super::[< __ $TY:lower >]::[< $ccmrx _input >]::[< CC $index S_A>] as [< CaptureSource $index >];
/// A capture/compare channel of the timer.
pub struct [< Channel $index >] {}
/// A capture channel of the timer.
pub struct [< Channel $index InputCapture>] {}
impl [< Channel $index >] {
/// Construct a new timer channel.
///
/// Note(unsafe): This function must only be called once. Once constructed, the
/// constructee guarantees to never modify the timer channel.
#[allow(dead_code)]
unsafe fn new() -> Self {
Self {}
}
/// Allow the channel to generate DMA requests.
#[allow(dead_code)]
pub fn listen_dma(&self) {
let regs = unsafe { &*<$TY>::ptr() };
regs.dier.modify(|_, w| w.[< cc $index de >]().set_bit());
}
/// Operate the channel as an output-compare.
///
/// # Args
/// * `value` - The value to compare the sampling timer's counter against.
#[allow(dead_code)]
pub fn to_output_compare(&self, value: $size) {
let regs = unsafe { &*<$TY>::ptr() };
let arr = regs.arr.read().bits() as $size;
assert!(value <= arr);
regs.[< ccr $index >].write(|w| w.ccr().bits(value));
regs.[< $ccmrx _output >]()
.modify(|_, w| unsafe { w.[< cc $index s >]().bits(0) });
}
/// Operate the channel in input-capture mode.
///
/// # Args
/// * `input` - The input source for the input capture event.
#[allow(dead_code)]
pub fn into_input_capture(self, input: [< CaptureSource $index >]) -> [< Channel $index InputCapture >]{
let regs = unsafe { &*<$TY>::ptr() };
regs.[< $ccmrx _input >]().modify(|_, w| w.[< cc $index s>]().variant(input));
[< Channel $index InputCapture >] {}
}
}
impl [< Channel $index InputCapture >] {
/// Get the latest capture from the channel.
#[allow(dead_code)]
pub fn latest_capture(&mut self) -> Result<Option<$size>, Option<$size>> {
// Note(unsafe): This channel owns all access to the specific timer channel.
// Only atomic operations on completed on the timer registers.
let regs = unsafe { &*<$TY>::ptr() };
let result = if regs.sr.read().[< cc $index if >]().bit_is_set() {
// Read the capture value. Reading the captured value clears the flag in the
// status register automatically.
Some(regs.[< ccr $index >].read().ccr().bits())
} else {
None
};
// Read SR again to check for a potential over-capture. If there is an
// overcapture, return an error.
if regs.sr.read().[< cc $index of >]().bit_is_set() {
regs.sr.modify(|_, w| w.[< cc $index of >]().clear_bit());
Err(result)
} else {
Ok(result)
}
}
/// Allow the channel to generate DMA requests.
#[allow(dead_code)]
pub fn listen_dma(&self) {
// Note(unsafe): This channel owns all access to the specific timer channel.
// Only atomic operations on completed on the timer registers.
let regs = unsafe { &*<$TY>::ptr() };
regs.dier.modify(|_, w| w.[< cc $index de >]().set_bit());
}
/// Enable the input capture to begin capturing timer values.
#[allow(dead_code)]
pub fn enable(&mut self) {
// Read the latest input capture to clear any pending data in the register.
let _ = self.latest_capture();
// Note(unsafe): This channel owns all access to the specific timer channel.
// Only atomic operations on completed on the timer registers.
let regs = unsafe { &*<$TY>::ptr() };
regs.ccer.modify(|_, w| w.[< cc $index e >]().set_bit());
}
/// Check if an over-capture event has occurred.
#[allow(dead_code)]
pub fn check_overcapture(&self) -> bool {
// Note(unsafe): This channel owns all access to the specific timer channel.
// Only atomic operations on completed on the timer registers.
let regs = unsafe { &*<$TY>::ptr() };
regs.sr.read().[< cc $index of >]().bit_is_set()
}
/// Configure the input capture input pre-filter.
///
/// # Args
/// * `filter` - The desired input filter stage configuration. Defaults to disabled.
#[allow(dead_code)]
pub fn configure_filter(&mut self, filter: super::InputFilter) {
// Note(unsafe): This channel owns all access to the specific timer channel.
// Only atomic operations on completed on the timer registers.
let regs = unsafe { &*<$TY>::ptr() };
regs.[< $ccmrx _input >]().modify(|_, w| w.[< ic $index f >]().bits(filter as u8));
}
}
// Note(unsafe): This manually implements DMA support for input-capture channels. This
// is safe as it is only completed once per channel and each DMA request is allocated to
// each channel as the owner.
unsafe impl TargetAddress<PeripheralToMemory> for [< Channel $index InputCapture >] {
type MemSize = $size;
const REQUEST_LINE: Option<u8> = Some(DMAReq::[< $TY _CH $index >]as u8);
fn address(&self) -> usize {
let regs = unsafe { &*<$TY>::ptr() };
&regs.[<ccr $index >] as *const _ as usize
}
}
}
};
}
timer_channels!(SamplingTimer, TIM2, u32);
timer_channels!(ShadowSamplingTimer, TIM3, u16);
timer_channels!(TimestampTimer, TIM5, u32);
timer_channels!(PounderTimestampTimer, TIM8, u16);