esp-hal/esp-hal-common/src/mcpwm/operator.rs
2022-11-30 00:55:39 +01:00

381 lines
14 KiB
Rust

use core::marker::PhantomData;
use crate::{
mcpwm::{timer::Timer, PwmPeripheral},
OutputPin,
};
/// A MCPWM operator
///
/// The PWM Operator submodule has the following functions:
/// * Generates a PWM signal pair, based on timing references obtained from the
/// corresponding PWM timer.
/// * Each signal out of the PWM signal pair includes a specific pattern of dead
/// time. (Not yet implemented)
/// * Superimposes a carrier on the PWM signal, if configured to do so. (Not yet
/// implemented)
/// * Handles response under fault conditions. (Not yet implemented)
pub struct Operator<const OP: u8, PWM> {
phantom: PhantomData<PWM>,
}
impl<const OP: u8, PWM: PwmPeripheral> Operator<OP, PWM> {
pub(super) fn new() -> Self {
// Side note:
// It would have been nice to deselect any timer reference on peripheral
// initialization.
// However experimentation (ESP32-S3) showed that writing `3` to timersel
// will not disable the timer reference but instead act as though `2` was
// written.
Operator {
phantom: PhantomData,
}
}
/// Select a [`Timer`] to be the timing reference for this operator
///
/// ### Note:
/// By default TIMER0 is used
pub fn set_timer<const TIM: u8>(&mut self, timer: &Timer<TIM, PWM>) {
let _ = timer;
// SAFETY:
// We only write to our OPERATORx_TIMERSEL register
let block = unsafe { &*PWM::block() };
block.operator_timersel.modify(|_, w| match OP {
0 => w.operator0_timersel().variant(TIM),
1 => w.operator1_timersel().variant(TIM),
2 => w.operator2_timersel().variant(TIM),
_ => {
unreachable!()
}
});
}
/// Use the A output with the given pin and configuration
pub fn with_pin_a<Pin: OutputPin>(
self,
pin: Pin,
config: PwmPinConfig<true>,
) -> PwmPin<Pin, PWM, OP, true> {
PwmPin::new(pin, config)
}
/// Use the B output with the given pin and configuration
pub fn with_pin_b<Pin: OutputPin>(
self,
pin: Pin,
config: PwmPinConfig<false>,
) -> PwmPin<Pin, PWM, OP, false> {
PwmPin::new(pin, config)
}
/// Use both the A and the B output with the given pins and configurations
pub fn with_pins<PinA: OutputPin, PinB: OutputPin>(
self,
pin_a: PinA,
config_a: PwmPinConfig<true>,
pin_b: PinB,
config_b: PwmPinConfig<false>,
) -> (PwmPin<PinA, PWM, OP, true>, PwmPin<PinB, PWM, OP, false>) {
(PwmPin::new(pin_a, config_a), PwmPin::new(pin_b, config_b))
}
}
/// Configuration describing how the operator generates a signal on a connected
/// pin
pub struct PwmPinConfig<const IS_A: bool> {
actions: PwmActions<IS_A>,
update_method: PwmUpdateMethod,
}
impl<const IS_A: bool> PwmPinConfig<IS_A> {
/// A configuration using [`PwmActions::UP_ACTIVE_HIGH`] and
/// [`PwmUpdateMethod::SYNC_ON_ZERO`]
pub const UP_ACTIVE_HIGH: Self =
Self::new(PwmActions::UP_ACTIVE_HIGH, PwmUpdateMethod::SYNC_ON_ZERO);
/// A configuration using [`PwmActions::UP_DOWN_ACTIVE_HIGH`] and
/// [`PwmUpdateMethod::SYNC_ON_ZERO`]
pub const UP_DOWN_ACTIVE_HIGH: Self = Self::new(
PwmActions::UP_DOWN_ACTIVE_HIGH,
PwmUpdateMethod::SYNC_ON_ZERO,
);
/// Get a configuration using the given `PwmActions` and `PwmUpdateMethod`
pub const fn new(actions: PwmActions<IS_A>, update_method: PwmUpdateMethod) -> Self {
PwmPinConfig {
actions,
update_method,
}
}
}
/// A pin driven by an MCPWM operator
pub struct PwmPin<Pin, PWM, const OP: u8, const IS_A: bool> {
_pin: Pin,
phantom: PhantomData<PWM>,
}
impl<Pin: OutputPin, PWM: PwmPeripheral, const OP: u8, const IS_A: bool>
PwmPin<Pin, PWM, OP, IS_A>
{
fn new(mut pin: Pin, config: PwmPinConfig<IS_A>) -> Self {
let output_signal = PWM::output_signal::<OP, IS_A>();
pin.enable_output(true)
.connect_peripheral_to_output(output_signal);
let mut pin = PwmPin {
_pin: pin,
phantom: PhantomData,
};
pin.set_actions(config.actions);
pin.set_update_method(config.update_method);
pin
}
/// Configure what actions should be taken on timing events
pub fn set_actions(&mut self, value: PwmActions<IS_A>) {
// SAFETY:
// We only write to our GENx_x register
let block = unsafe { &*PWM::block() };
let bits = value.0;
// SAFETY:
// `bits` is a valid bit pattern
unsafe {
match (OP, IS_A) {
(0, true) => block.gen0_a.write(|w| w.bits(bits)),
(1, true) => block.gen1_a.write(|w| w.bits(bits)),
(2, true) => block.gen2_a.write(|w| w.bits(bits)),
(0, false) => block.gen0_b.write(|w| w.bits(bits)),
(1, false) => block.gen1_b.write(|w| w.bits(bits)),
(2, false) => block.gen2_b.write(|w| w.bits(bits)),
_ => unreachable!(),
}
}
}
/// Set how a new timestamp syncs with the timer
#[cfg(esp32)]
pub fn set_update_method(&mut self, update_method: PwmUpdateMethod) {
// SAFETY:
// We only write to our GENx_x_UPMETHOD register
let block = unsafe { &*PWM::block() };
let bits = update_method.0;
match (OP, IS_A) {
(0, true) => block
.gen0_stmp_cfg
.modify(|_, w| w.gen0_a_upmethod().variant(bits)),
(1, true) => block
.gen1_stmp_cfg
.modify(|_, w| w.gen1_a_upmethod().variant(bits)),
(2, true) => block
.gen2_stmp_cfg
.modify(|_, w| w.gen2_a_upmethod().variant(bits)),
(0, false) => block
.gen0_stmp_cfg
.modify(|_, w| w.gen0_b_upmethod().variant(bits)),
(1, false) => block
.gen1_stmp_cfg
.modify(|_, w| w.gen1_b_upmethod().variant(bits)),
(2, false) => block
.gen2_stmp_cfg
.modify(|_, w| w.gen2_b_upmethod().variant(bits)),
_ => {
unreachable!()
}
}
}
/// Set how a new timestamp syncs with the timer
#[cfg(esp32s3)]
pub fn set_update_method(&mut self, update_method: PwmUpdateMethod) {
// SAFETY:
// We only write to our GENx_x_UPMETHOD register
let block = unsafe { &*PWM::block() };
let bits = update_method.0;
match (OP, IS_A) {
(0, true) => block
.cmpr0_cfg
.modify(|_, w| w.cmpr0_a_upmethod().variant(bits)),
(1, true) => block
.cmpr1_cfg
.modify(|_, w| w.cmpr1_a_upmethod().variant(bits)),
(2, true) => block
.cmpr2_cfg
.modify(|_, w| w.cmpr2_a_upmethod().variant(bits)),
(0, false) => block
.cmpr0_cfg
.modify(|_, w| w.cmpr0_b_upmethod().variant(bits)),
(1, false) => block
.cmpr1_cfg
.modify(|_, w| w.cmpr1_b_upmethod().variant(bits)),
(2, false) => block
.cmpr2_cfg
.modify(|_, w| w.cmpr2_b_upmethod().variant(bits)),
_ => {
unreachable!()
}
}
}
/// Set how a new timestamp syncs with the timer.
/// The written value will take effect according to the set
/// [`PwmUpdateMethod`].
#[cfg(esp32)]
pub fn set_timestamp(&mut self, value: u16) {
// SAFETY:
// We only write to our GENx_TSTMP_x register
let block = unsafe { &*PWM::block() };
match (OP, IS_A) {
(0, true) => block.gen0_tstmp_a.write(|w| w.gen0_a().variant(value)),
(1, true) => block.gen1_tstmp_a.write(|w| w.gen1_a().variant(value)),
(2, true) => block.gen2_tstmp_a.write(|w| w.gen2_a().variant(value)),
(0, false) => block.gen0_tstmp_b.write(|w| w.gen0_b().variant(value)),
(1, false) => block.gen1_tstmp_b.write(|w| w.gen1_b().variant(value)),
(2, false) => block.gen2_tstmp_b.write(|w| w.gen2_b().variant(value)),
_ => {
unreachable!()
}
}
}
/// Write a new timestamp.
/// The written value will take effect according to the set
/// [`PwmUpdateMethod`].
#[cfg(esp32s3)]
pub fn set_timestamp(&mut self, value: u16) {
// SAFETY:
// We only write to our GENx_TSTMP_x register
let block = unsafe { &*PWM::block() };
match (OP, IS_A) {
(0, true) => block.cmpr0_value0.write(|w| w.cmpr0_a().variant(value)),
(1, true) => block.cmpr1_value0.write(|w| w.cmpr1_a().variant(value)),
(2, true) => block.cmpr2_value0.write(|w| w.cmpr2_a().variant(value)),
(0, false) => block.cmpr0_value1.write(|w| w.cmpr0_b().variant(value)),
(1, false) => block.cmpr1_value1.write(|w| w.cmpr1_b().variant(value)),
(2, false) => block.cmpr2_value1.write(|w| w.cmpr2_b().variant(value)),
_ => {
unreachable!()
}
}
}
}
/// An action the operator applies to an output
#[non_exhaustive]
#[repr(u32)]
pub enum UpdateAction {
/// Clear the output by setting it to a low level.
SetLow = 1,
/// Set the to a high level.
SetHigh = 2,
/// Change the current output level to the opposite value.
/// If it is currently pulled high, pull it low, or vice versa.
Toggle = 3,
}
/// Settings for what actions should be taken on timing events
///
/// ### Note:
/// The hardware supports using a timestamp A event to trigger an action on
/// output B or vice versa. For clearer ownership semantics this HAL does not
/// support such configurations.
pub struct PwmActions<const IS_A: bool>(u32);
impl<const IS_A: bool> PwmActions<IS_A> {
/// Using this setting together with a timer configured with
/// [`PwmWorkingMode::Increase`](super::timer::PwmWorkingMode::Increase)
/// will set the output high for a duration proportional to the set
/// timestamp.
pub const UP_ACTIVE_HIGH: Self = Self::empty()
.on_up_counting_timer_equals_zero(UpdateAction::SetHigh)
.on_up_counting_timer_equals_timestamp(UpdateAction::SetLow);
/// Using this setting together with a timer configured with
/// [`PwmWorkingMode::UpDown`](super::timer::PwmWorkingMode::UpDown) will
/// set the output high for a duration proportional to the set
/// timestamp.
pub const UP_DOWN_ACTIVE_HIGH: Self = Self::empty()
.on_down_counting_timer_equals_timestamp(UpdateAction::SetHigh)
.on_up_counting_timer_equals_timestamp(UpdateAction::SetLow);
/// `PwmActions` with no `UpdateAction`s set
pub const fn empty() -> Self {
PwmActions(0)
}
/// Choose an `UpdateAction` for an `UTEZ` event
pub const fn on_up_counting_timer_equals_zero(self, action: UpdateAction) -> Self {
self.with_value_at_offset(action as u32, 0)
}
/// Choose an `UpdateAction` for an `UTEP` event
pub const fn on_up_counting_timer_equals_period(self, action: UpdateAction) -> Self {
self.with_value_at_offset(action as u32, 2)
}
/// Choose an `UpdateAction` for an `UTEA`/`UTEB` event
pub const fn on_up_counting_timer_equals_timestamp(self, action: UpdateAction) -> Self {
match IS_A {
true => self.with_value_at_offset(action as u32, 4),
false => self.with_value_at_offset(action as u32, 6),
}
}
/// Choose an `UpdateAction` for an `DTEZ` event
pub const fn on_down_counting_timer_equals_zero(self, action: UpdateAction) -> Self {
self.with_value_at_offset(action as u32, 12)
}
/// Choose an `UpdateAction` for an `DTEP` event
pub const fn on_down_counting_timer_equals_period(self, action: UpdateAction) -> Self {
self.with_value_at_offset(action as u32, 14)
}
/// Choose an `UpdateAction` for an `DTEA`/`DTEB` event
pub const fn on_down_counting_timer_equals_timestamp(self, action: UpdateAction) -> Self {
match IS_A {
true => self.with_value_at_offset(action as u32, 16),
false => self.with_value_at_offset(action as u32, 18),
}
}
const fn with_value_at_offset(self, value: u32, offset: u32) -> Self {
let mask = !(0b11 << offset);
let value = (self.0 & mask) | (value << offset);
PwmActions(value)
}
}
/// Settings for when [`PwmPin::set_timestamp`] takes effect
///
/// Multiple syncing triggers can be set.
pub struct PwmUpdateMethod(u8);
impl PwmUpdateMethod {
/// New timestamp will be applied immediately
pub const SYNC_IMMEDIATLY: Self = Self::empty();
/// New timestamp will be applied when timer is equal to zero
pub const SYNC_ON_ZERO: Self = Self::empty().sync_on_timer_equals_zero();
/// New timestamp will be applied when timer is equal to period
pub const SYNC_ON_PERIOD: Self = Self::empty().sync_on_timer_equals_period();
/// `PwmUpdateMethod` with no sync triggers.
/// Corresponds to syncing immediately
pub const fn empty() -> Self {
PwmUpdateMethod(0)
}
/// Enable syncing new timestamp values when timer is equal to zero
pub const fn sync_on_timer_equals_zero(mut self) -> Self {
self.0 |= 0b0001;
self
}
/// Enable syncing new timestamp values when timer is equal to period
pub const fn sync_on_timer_equals_period(mut self) -> Self {
self.0 |= 0b0010;
self
}
}