embassy/embassy-stm32/src/gpio.rs

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#![macro_use]
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use core::convert::Infallible;
use core::marker::PhantomData;
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use embassy::util::Unborrow;
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use embassy_extras::{impl_unborrow, unborrow};
use embedded_hal::digital::v2::{InputPin, OutputPin, StatefulOutputPin};
use crate::pac;
use crate::pac::gpio::{self, vals};
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/// Pull setting for an input.
#[derive(Debug, Eq, PartialEq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum Pull {
None,
Up,
Down,
}
/// GPIO input driver.
pub struct Input<'d, T: Pin> {
pub(crate) pin: T,
phantom: PhantomData<&'d mut T>,
}
impl<'d, T: Pin> Input<'d, T> {
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pub fn new(pin: impl Unborrow<Target = T> + 'd, pull: Pull) -> Self {
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unborrow!(pin);
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cortex_m::interrupt::free(|_| unsafe {
let r = pin.block();
let n = pin.pin() as usize;
let val = match pull {
Pull::None => vals::Pupdr::FLOATING,
Pull::Up => vals::Pupdr::PULLUP,
Pull::Down => vals::Pupdr::PULLDOWN,
};
r.pupdr().modify(|w| w.set_pupdr(n, val));
r.otyper().modify(|w| w.set_ot(n, vals::Ot::PUSHPULL));
r.moder().modify(|w| w.set_moder(n, vals::Moder::INPUT));
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});
Self {
pin,
phantom: PhantomData,
}
}
}
impl<'d, T: Pin> Drop for Input<'d, T> {
fn drop(&mut self) {
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cortex_m::interrupt::free(|_| unsafe {
let r = self.pin.block();
let n = self.pin.pin() as usize;
r.pupdr().modify(|w| w.set_pupdr(n, vals::Pupdr::FLOATING));
});
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}
}
impl<'d, T: Pin> InputPin for Input<'d, T> {
type Error = Infallible;
fn is_high(&self) -> Result<bool, Self::Error> {
self.is_low().map(|v| !v)
}
fn is_low(&self) -> Result<bool, Self::Error> {
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let state = unsafe { self.pin.block().idr().read().idr(self.pin.pin() as _) };
Ok(state == vals::Idr::LOW)
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}
}
/// Digital input or output level.
#[derive(Debug, Eq, PartialEq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum Level {
Low,
High,
}
/// GPIO output driver.
pub struct Output<'d, T: Pin> {
pub(crate) pin: T,
phantom: PhantomData<&'d mut T>,
}
impl<'d, T: Pin> Output<'d, T> {
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pub fn new(pin: impl Unborrow<Target = T> + 'd, initial_output: Level) -> Self {
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unborrow!(pin);
match initial_output {
Level::High => pin.set_high(),
Level::Low => pin.set_low(),
}
cortex_m::interrupt::free(|_| unsafe {
let r = pin.block();
let n = pin.pin() as usize;
r.pupdr().modify(|w| w.set_pupdr(n, vals::Pupdr::FLOATING));
r.moder().modify(|w| w.set_moder(n, vals::Moder::OUTPUT));
});
Self {
pin,
phantom: PhantomData,
}
}
}
impl<'d, T: Pin> Drop for Output<'d, T> {
fn drop(&mut self) {
cortex_m::interrupt::free(|_| unsafe {
let r = self.pin.block();
let n = self.pin.pin() as usize;
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r.pupdr().modify(|w| w.set_pupdr(n, vals::Pupdr::FLOATING));
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r.moder().modify(|w| w.set_moder(n, vals::Moder::INPUT));
});
}
}
impl<'d, T: Pin> OutputPin for Output<'d, T> {
type Error = Infallible;
/// Set the output as high.
fn set_high(&mut self) -> Result<(), Self::Error> {
self.pin.set_high();
Ok(())
}
/// Set the output as low.
fn set_low(&mut self) -> Result<(), Self::Error> {
self.pin.set_low();
Ok(())
}
}
impl<'d, T: Pin> StatefulOutputPin for Output<'d, T> {
/// Is the output pin set as high?
fn is_set_high(&self) -> Result<bool, Self::Error> {
self.is_set_low().map(|v| !v)
}
/// Is the output pin set as low?
fn is_set_low(&self) -> Result<bool, Self::Error> {
let state = unsafe { self.pin.block().odr().read().odr(self.pin.pin() as _) };
Ok(state == vals::Odr::LOW)
}
}
pub(crate) mod sealed {
use super::*;
pub trait Pin {
fn pin_port(&self) -> u8;
#[inline]
fn _pin(&self) -> u8 {
self.pin_port() % 16
}
#[inline]
fn _port(&self) -> u8 {
self.pin_port() / 16
}
#[inline]
fn block(&self) -> gpio::Gpio {
pac::GPIO(self._port() as _)
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}
/// Set the output as high.
#[inline]
fn set_high(&self) {
unsafe {
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let n = self._pin() as _;
self.block().bsrr().write(|w| w.set_bs(n, true));
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}
}
/// Set the output as low.
#[inline]
fn set_low(&self) {
unsafe {
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let n = self._pin() as _;
self.block().bsrr().write(|w| w.set_br(n, true));
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}
}
}
pub trait OptionalPin {}
}
pub trait Pin: sealed::Pin + Sized {
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type ExtiChannel: crate::exti::Channel;
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/// Number of the pin within the port (0..31)
#[inline]
fn pin(&self) -> u8 {
self._pin()
}
/// Port of the pin
#[inline]
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fn port(&self) -> u8 {
self._port()
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}
#[inline]
fn psel_bits(&self) -> u32 {
self.pin_port() as u32
}
/// Convert from concrete pin type PX_XX to type erased `AnyPin`.
#[inline]
fn degrade(self) -> AnyPin {
AnyPin {
pin_port: self.pin_port(),
}
}
}
// Type-erased GPIO pin
pub struct AnyPin {
pin_port: u8,
}
impl AnyPin {
#[inline]
pub unsafe fn steal(pin_port: u8) -> Self {
Self { pin_port }
}
}
impl_unborrow!(AnyPin);
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impl Pin for AnyPin {
type ExtiChannel = crate::exti::AnyChannel;
}
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impl sealed::Pin for AnyPin {
#[inline]
fn pin_port(&self) -> u8 {
self.pin_port
}
}
// ====================
pub trait OptionalPin: sealed::OptionalPin + Sized {
type Pin: Pin;
fn pin(&self) -> Option<&Self::Pin>;
fn pin_mut(&mut self) -> Option<&mut Self::Pin>;
#[inline]
fn psel_bits(&self) -> u32 {
self.pin().map_or(1u32 << 31, |pin| Pin::psel_bits(pin))
}
/// Convert from concrete pin type PX_XX to type erased `Option<AnyPin>`.
#[inline]
fn degrade_optional(mut self) -> Option<AnyPin> {
self.pin_mut()
.map(|pin| unsafe { core::ptr::read(pin) }.degrade())
}
}
impl<T: Pin> sealed::OptionalPin for T {}
impl<T: Pin> OptionalPin for T {
type Pin = T;
#[inline]
fn pin(&self) -> Option<&T> {
Some(self)
}
#[inline]
fn pin_mut(&mut self) -> Option<&mut T> {
Some(self)
}
}
#[derive(Clone, Copy, Debug)]
pub struct NoPin;
impl_unborrow!(NoPin);
impl sealed::OptionalPin for NoPin {}
impl OptionalPin for NoPin {
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type Pin = AnyPin;
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#[inline]
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fn pin(&self) -> Option<&AnyPin> {
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None
}
#[inline]
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fn pin_mut(&mut self) -> Option<&mut AnyPin> {
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None
}
}
// ====================
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macro_rules! impl_gpio_pin {
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($type:ident, $port_num:expr, $pin_num:expr, $exti_ch:ident) => {
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impl crate::gpio::Pin for peripherals::$type {
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type ExtiChannel = peripherals::$exti_ch;
}
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impl crate::gpio::sealed::Pin for peripherals::$type {
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#[inline]
fn pin_port(&self) -> u8 {
$port_num * 16 + $pin_num
}
}
};
}