embassy/embassy-nrf/src/qdec.rs
2024-04-05 00:48:46 +02:00

289 lines
8.1 KiB
Rust

//! Quadrature decoder (QDEC) driver.
#![macro_use]
use core::future::poll_fn;
use core::marker::PhantomData;
use core::task::Poll;
use embassy_hal_internal::{into_ref, PeripheralRef};
use embassy_sync::waitqueue::AtomicWaker;
use crate::gpio::{AnyPin, Pin as GpioPin, SealedPin as _};
use crate::interrupt::typelevel::Interrupt;
use crate::{interrupt, Peripheral};
/// Quadrature decoder driver.
pub struct Qdec<'d, T: Instance> {
_p: PeripheralRef<'d, T>,
}
/// QDEC config
#[non_exhaustive]
pub struct Config {
/// Number of samples
pub num_samples: NumSamples,
/// Sample period
pub period: SamplePeriod,
/// Set LED output pin polarity
pub led_polarity: LedPolarity,
/// Enable/disable input debounce filters
pub debounce: bool,
/// Time period the LED is switched ON prior to sampling (0..511 us).
pub led_pre_usecs: u16,
}
impl Default for Config {
fn default() -> Self {
Self {
num_samples: NumSamples::_1smpl,
period: SamplePeriod::_256us,
led_polarity: LedPolarity::ActiveHigh,
debounce: true,
led_pre_usecs: 0,
}
}
}
/// Interrupt handler.
pub struct InterruptHandler<T: Instance> {
_phantom: PhantomData<T>,
}
impl<T: Instance> interrupt::typelevel::Handler<T::Interrupt> for InterruptHandler<T> {
unsafe fn on_interrupt() {
T::regs().intenclr.write(|w| w.reportrdy().clear());
T::state().waker.wake();
}
}
impl<'d, T: Instance> Qdec<'d, T> {
/// Create a new QDEC.
pub fn new(
qdec: impl Peripheral<P = T> + 'd,
_irq: impl interrupt::typelevel::Binding<T::Interrupt, InterruptHandler<T>> + 'd,
a: impl Peripheral<P = impl GpioPin> + 'd,
b: impl Peripheral<P = impl GpioPin> + 'd,
config: Config,
) -> Self {
into_ref!(qdec, a, b);
Self::new_inner(qdec, a.map_into(), b.map_into(), None, config)
}
/// Create a new QDEC, with a pin for LED output.
pub fn new_with_led(
qdec: impl Peripheral<P = T> + 'd,
_irq: impl interrupt::typelevel::Binding<T::Interrupt, InterruptHandler<T>> + 'd,
a: impl Peripheral<P = impl GpioPin> + 'd,
b: impl Peripheral<P = impl GpioPin> + 'd,
led: impl Peripheral<P = impl GpioPin> + 'd,
config: Config,
) -> Self {
into_ref!(qdec, a, b, led);
Self::new_inner(qdec, a.map_into(), b.map_into(), Some(led.map_into()), config)
}
fn new_inner(
p: PeripheralRef<'d, T>,
a: PeripheralRef<'d, AnyPin>,
b: PeripheralRef<'d, AnyPin>,
led: Option<PeripheralRef<'d, AnyPin>>,
config: Config,
) -> Self {
let r = T::regs();
// Select pins.
a.conf().write(|w| w.input().connect().pull().pullup());
b.conf().write(|w| w.input().connect().pull().pullup());
r.psel.a.write(|w| unsafe { w.bits(a.psel_bits()) });
r.psel.b.write(|w| unsafe { w.bits(b.psel_bits()) });
if let Some(led_pin) = &led {
led_pin.conf().write(|w| w.dir().output());
r.psel.led.write(|w| unsafe { w.bits(led_pin.psel_bits()) });
}
// Enables/disable input debounce filters
r.dbfen.write(|w| match config.debounce {
true => w.dbfen().enabled(),
false => w.dbfen().disabled(),
});
// Set LED output pin polarity
r.ledpol.write(|w| match config.led_polarity {
LedPolarity::ActiveHigh => w.ledpol().active_high(),
LedPolarity::ActiveLow => w.ledpol().active_low(),
});
// Set time period the LED is switched ON prior to sampling (0..511 us).
r.ledpre
.write(|w| unsafe { w.ledpre().bits(config.led_pre_usecs.min(511)) });
// Set sample period
r.sampleper.write(|w| match config.period {
SamplePeriod::_128us => w.sampleper()._128us(),
SamplePeriod::_256us => w.sampleper()._256us(),
SamplePeriod::_512us => w.sampleper()._512us(),
SamplePeriod::_1024us => w.sampleper()._1024us(),
SamplePeriod::_2048us => w.sampleper()._2048us(),
SamplePeriod::_4096us => w.sampleper()._4096us(),
SamplePeriod::_8192us => w.sampleper()._8192us(),
SamplePeriod::_16384us => w.sampleper()._16384us(),
SamplePeriod::_32ms => w.sampleper()._32ms(),
SamplePeriod::_65ms => w.sampleper()._65ms(),
SamplePeriod::_131ms => w.sampleper()._131ms(),
});
T::Interrupt::unpend();
unsafe { T::Interrupt::enable() };
// Enable peripheral
r.enable.write(|w| w.enable().set_bit());
// Start sampling
unsafe { r.tasks_start.write(|w| w.bits(1)) };
Self { _p: p }
}
/// Perform an asynchronous read of the decoder.
/// The returned future can be awaited to obtain the number of steps.
///
/// If the future is dropped, the read is cancelled.
///
/// # Example
///
/// ```no_run
/// use embassy_nrf::qdec::{self, Qdec};
/// use embassy_nrf::{bind_interrupts, peripherals};
///
/// bind_interrupts!(struct Irqs {
/// QDEC => qdec::InterruptHandler<peripherals::QDEC>;
/// });
///
/// # async {
/// # let p: embassy_nrf::Peripherals = todo!();
/// let config = qdec::Config::default();
/// let mut q = Qdec::new(p.QDEC, Irqs, p.P0_31, p.P0_30, config);
/// let delta = q.read().await;
/// # };
/// ```
pub async fn read(&mut self) -> i16 {
let t = T::regs();
t.intenset.write(|w| w.reportrdy().set());
unsafe { t.tasks_readclracc.write(|w| w.bits(1)) };
poll_fn(|cx| {
T::state().waker.register(cx.waker());
if t.events_reportrdy.read().bits() == 0 {
Poll::Pending
} else {
t.events_reportrdy.reset();
let acc = t.accread.read().bits();
Poll::Ready(acc as i16)
}
})
.await
}
}
/// Sample period
#[derive(Debug, Eq, PartialEq, Clone, Copy)]
pub enum SamplePeriod {
/// 128 us
_128us,
/// 256 us
_256us,
/// 512 us
_512us,
/// 1024 us
_1024us,
/// 2048 us
_2048us,
/// 4096 us
_4096us,
/// 8192 us
_8192us,
/// 16384 us
_16384us,
/// 32 ms
_32ms,
/// 65 ms
_65ms,
/// 131 ms
_131ms,
}
/// Number of samples taken.
#[derive(Debug, Eq, PartialEq, Clone, Copy)]
pub enum NumSamples {
/// 10 samples
_10smpl,
/// 40 samples
_40smpl,
/// 80 samples
_80smpl,
/// 120 samples
_120smpl,
/// 160 samples
_160smpl,
/// 200 samples
_200smpl,
/// 240 samples
_240smpl,
/// 280 samples
_280smpl,
/// 1 sample
_1smpl,
}
/// LED polarity
#[derive(Debug, Eq, PartialEq, Clone, Copy)]
pub enum LedPolarity {
/// Active high (a high output turns on the LED).
ActiveHigh,
/// Active low (a low output turns on the LED).
ActiveLow,
}
/// Peripheral static state
pub(crate) struct State {
waker: AtomicWaker,
}
impl State {
pub(crate) const fn new() -> Self {
Self {
waker: AtomicWaker::new(),
}
}
}
pub(crate) trait SealedInstance {
fn regs() -> &'static crate::pac::qdec::RegisterBlock;
fn state() -> &'static State;
}
/// qdec peripheral instance.
#[allow(private_bounds)]
pub trait Instance: Peripheral<P = Self> + SealedInstance + 'static + Send {
/// Interrupt for this peripheral.
type Interrupt: interrupt::typelevel::Interrupt;
}
macro_rules! impl_qdec {
($type:ident, $pac_type:ident, $irq:ident) => {
impl crate::qdec::SealedInstance for peripherals::$type {
fn regs() -> &'static crate::pac::qdec::RegisterBlock {
unsafe { &*pac::$pac_type::ptr() }
}
fn state() -> &'static crate::qdec::State {
static STATE: crate::qdec::State = crate::qdec::State::new();
&STATE
}
}
impl crate::qdec::Instance for peripherals::$type {
type Interrupt = crate::interrupt::typelevel::$irq;
}
};
}