770: Add open-drain support for embassy-rp r=danbev a=danbev

This commit adds open-drain support for embassy-rp by adding a new type
named `embassy_rp::gpio::OutputOpenDrain`.



Co-authored-by: Daniel Bevenius <daniel.bevenius@gmail.com>
This commit is contained in:
bors[bot] 2022-05-21 10:26:55 +00:00 committed by GitHub
commit 36a1f20364
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@ -86,7 +86,6 @@ pub struct Output<'d, T: Pin> {
}
impl<'d, T: Pin> Output<'d, T> {
// TODO opendrain
pub fn new(pin: impl Unborrow<Target = T> + 'd, initial_output: Level) -> Self {
unborrow!(pin);
@ -155,6 +154,89 @@ impl<'d, T: Pin> Drop for Output<'d, T> {
}
}
/// GPIO output open-drain.
pub struct OutputOpenDrain<'d, T: Pin> {
pin: T,
phantom: PhantomData<&'d mut T>,
}
impl<'d, T: Pin> OutputOpenDrain<'d, T> {
#[inline]
pub fn new(pin: impl Unborrow<Target = T> + 'd, initial_output: Level) -> Self {
unborrow!(pin);
unsafe {
let val = 1 << pin.pin();
pin.io().ctrl().write(|w| {
w.set_funcsel(pac::io::vals::Gpio0CtrlFuncsel::SIO_0.0);
});
pin.sio_out().value_clr().write_value(val);
match initial_output {
Level::High => {
// For Open Drain High, disable the output pin.
pin.sio_oe().value_clr().write_value(val);
}
Level::Low => {
// For Open Drain Low, enable the output pin.
pin.sio_oe().value_set().write_value(val);
}
}
}
Self {
pin,
phantom: PhantomData,
}
}
/// Set the output as high.
#[inline]
pub fn set_high(&mut self) {
// For Open Drain High, disable the output pin.
unsafe {
self.pin
.sio_oe()
.value_clr()
.write_value(1 << self.pin.pin());
}
}
/// Set the output as low.
#[inline]
pub fn set_low(&mut self) {
// For Open Drain Low, enable the output pin.
unsafe {
self.pin
.sio_oe()
.value_set()
.write_value(1 << self.pin.pin());
}
}
/// Is the output level high?
#[inline]
pub fn is_set_high(&self) -> bool {
let val = 1 << self.pin.pin();
unsafe { (self.pin.sio_oe().value().read() & val) == 0 }
}
/// Is the output level low?
#[inline]
pub fn is_set_low(&self) -> bool {
!self.is_set_high()
}
/// Toggle pin output
#[inline]
pub fn toggle(&mut self) {
let val = 1 << self.pin.pin();
unsafe {
self.pin.sio_out().value_xor().write_value(val);
}
}
}
pub(crate) mod sealed {
use super::*;
@ -322,6 +404,38 @@ mod eh02 {
Ok(self.toggle())
}
}
impl<'d, T: Pin> embedded_hal_02::digital::v2::OutputPin for OutputOpenDrain<'d, T> {
type Error = Infallible;
#[inline]
fn set_high(&mut self) -> Result<(), Self::Error> {
Ok(self.set_high())
}
#[inline]
fn set_low(&mut self) -> Result<(), Self::Error> {
Ok(self.set_low())
}
}
impl<'d, T: Pin> embedded_hal_02::digital::v2::StatefulOutputPin for OutputOpenDrain<'d, T> {
fn is_set_high(&self) -> Result<bool, Self::Error> {
Ok(self.is_set_high())
}
fn is_set_low(&self) -> Result<bool, Self::Error> {
Ok(self.is_set_low())
}
}
impl<'d, T: Pin> embedded_hal_02::digital::v2::ToggleableOutputPin for OutputOpenDrain<'d, T> {
type Error = Infallible;
#[inline]
fn toggle(&mut self) -> Result<(), Self::Error> {
Ok(self.toggle())
}
}
}
#[cfg(feature = "unstable-traits")]