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rp/adc: rewrite the module

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- don't require an irq binding for blocking-only adc
- abstract adc pins into an AnyPin like interface, erasing the actual
  peripheral type at runtime.
- add pull-up/pull-down functions for adc pins
- add a test (mostly a copy of the example, to be honest)
- configure adc pads according to datasheet
- report conversion errors (although they seem exceedingly rare?)
- drop embedded-hal interfaces. embedded-hal channels can do neither
  AnyPin nor pullup/pulldown without encoding both into the type
This commit is contained in:
pennae
2023-07-05 20:05:34 +02:00
parent 46a4600952
commit 972cdd4265
4 changed files with 238 additions and 94 deletions
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227
embassy-rp/src/adc.rs
View File

@ -3,22 +3,17 @@ use core::marker::PhantomData;
use core::sync::atomic::{compiler_fence, Ordering};
use core::task::Poll;
use embassy_hal_common::{into_ref, PeripheralRef};
use embassy_sync::waitqueue::AtomicWaker;
use embedded_hal_02::adc::{Channel, OneShot};
use crate::gpio::Pin;
use crate::gpio::sealed::Pin as GpioPin;
use crate::gpio::{self, AnyPin, Pull};
use crate::interrupt::typelevel::Binding;
use crate::interrupt::InterruptExt;
use crate::peripherals::ADC;
use crate::{interrupt, pac, peripherals, Peripheral};
static WAKER: AtomicWaker = AtomicWaker::new();
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
#[non_exhaustive]
pub enum Error {
// No errors for now
}
static WAKER: AtomicWaker = AtomicWaker::new();
#[non_exhaustive]
pub struct Config {}
@ -28,11 +23,65 @@ impl Default for Config {
Self {}
}
}
pub struct Adc<'d> {
phantom: PhantomData<&'d ADC>,
pub struct Pin<'p> {
pin: PeripheralRef<'p, AnyPin>,
}
impl<'d> Adc<'d> {
impl<'p> Pin<'p> {
pub fn new(pin: impl Peripheral<P = impl AdcPin + 'p> + 'p, pull: Pull) -> Self {
into_ref!(pin);
pin.pad_ctrl().modify(|w| {
// manual says:
//
// > When using an ADC input shared with a GPIO pin, the pin’s
// > digital functions must be disabled by setting IE low and OD
// > high in the pin’s pad control register
w.set_ie(false);
w.set_od(true);
w.set_pue(pull == Pull::Up);
w.set_pde(pull == Pull::Down);
});
Self { pin: pin.map_into() }
}
fn channel(&self) -> u8 {
// this requires adc pins to be sequential and matching the adc channels,
// which is the case for rp2040
self.pin._pin() - 26
}
}
impl<'d> Drop for Pin<'d> {
fn drop(&mut self) {
self.pin.pad_ctrl().modify(|w| {
w.set_ie(true);
w.set_od(false);
w.set_pue(false);
w.set_pde(true);
});
}
}
#[derive(Debug, Eq, PartialEq, Copy, Clone)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum Error {
ConversionFailed,
}
pub trait Mode {}
pub struct Async;
impl Mode for Async {}
pub struct Blocking;
impl Mode for Blocking {}
pub struct Adc<'d, M: Mode> {
phantom: PhantomData<(&'d ADC, M)>,
}
impl<'d, M: Mode> Adc<'d, M> {
#[inline]
fn regs() -> pac::adc::Adc {
pac::ADC
@ -45,11 +94,7 @@ impl<'d> Adc<'d> {
ret
}
pub fn new(
_inner: impl Peripheral<P = ADC> + 'd,
_irq: impl Binding<interrupt::typelevel::ADC_IRQ_FIFO, InterruptHandler>,
_config: Config,
) -> Self {
fn setup() {
let reset = Self::reset();
crate::reset::reset(reset);
crate::reset::unreset_wait(reset);
@ -58,6 +103,43 @@ impl<'d> Adc<'d> {
r.cs().write(|w| w.set_en(true));
// Wait for ADC ready
while !r.cs().read().ready() {}
}
fn sample_blocking(channel: u8) -> Result<u16, Error> {
let r = Self::regs();
r.cs().modify(|w| {
w.set_ainsel(channel);
w.set_start_once(true);
w.set_err(true);
});
while !r.cs().read().ready() {}
match r.cs().read().err() {
true => Err(Error::ConversionFailed),
false => Ok(r.result().read().result().into()),
}
}
pub fn blocking_read(&mut self, pin: &mut Pin) -> Result<u16, Error> {
Self::sample_blocking(pin.channel())
}
pub fn blocking_read_temperature(&mut self) -> Result<u16, Error> {
let r = Self::regs();
r.cs().modify(|w| w.set_ts_en(true));
while !r.cs().read().ready() {}
let result = Self::sample_blocking(4);
r.cs().modify(|w| w.set_ts_en(false));
result
}
}
impl<'d> Adc<'d, Async> {
pub fn new(
_inner: impl Peripheral<P = ADC> + 'd,
_irq: impl Binding<interrupt::typelevel::ADC_IRQ_FIFO, InterruptHandler>,
_config: Config,
) -> Self {
Self::setup();
// Setup IRQ
interrupt::ADC_IRQ_FIFO.unpend();
@ -80,76 +162,42 @@ impl<'d> Adc<'d> {
.await;
}
pub async fn read<PIN: Channel<Adc<'d>, ID = u8> + Pin>(&mut self, pin: &mut PIN) -> u16 {
async fn sample_async(channel: u8) -> Result<u16, Error> {
let r = Self::regs();
// disable pull-down and pull-up resistors
// pull-down resistors are enabled by default
pin.pad_ctrl().modify(|w| {
w.set_ie(true);
let (pu, pd) = (false, false);
w.set_pue(pu);
w.set_pde(pd);
});
r.cs().modify(|w| {
w.set_ainsel(PIN::channel());
w.set_start_once(true)
w.set_ainsel(channel);
w.set_start_once(true);
w.set_err(true);
});
Self::wait_for_ready().await;
r.result().read().result().into()
match r.cs().read().err() {
true => Err(Error::ConversionFailed),
false => Ok(r.result().read().result().into()),
}
}
pub async fn read_temperature(&mut self) -> u16 {
pub async fn read(&mut self, pin: &mut Pin<'_>) -> Result<u16, Error> {
Self::sample_async(pin.channel()).await
}
pub async fn read_temperature(&mut self) -> Result<u16, Error> {
let r = Self::regs();
r.cs().modify(|w| w.set_ts_en(true));
if !r.cs().read().ready() {
Self::wait_for_ready().await;
}
r.cs().modify(|w| {
w.set_ainsel(4);
w.set_start_once(true)
});
Self::wait_for_ready().await;
r.result().read().result().into()
}
pub fn blocking_read<PIN: Channel<Adc<'d>, ID = u8> + Pin>(&mut self, pin: &mut PIN) -> u16 {
let r = Self::regs();
pin.pad_ctrl().modify(|w| {
w.set_ie(true);
let (pu, pd) = (false, false);
w.set_pue(pu);
w.set_pde(pd);
});
r.cs().modify(|w| {
w.set_ainsel(PIN::channel());
w.set_start_once(true)
});
while !r.cs().read().ready() {}
r.result().read().result().into()
}
pub fn blocking_read_temperature(&mut self) -> u16 {
let r = Self::regs();
r.cs().modify(|w| w.set_ts_en(true));
while !r.cs().read().ready() {}
r.cs().modify(|w| {
w.set_ainsel(4);
w.set_start_once(true)
});
while !r.cs().read().ready() {}
r.result().read().result().into()
let result = Self::sample_async(4).await;
r.cs().modify(|w| w.set_ts_en(false));
result
}
}
macro_rules! impl_pin {
($pin:ident, $channel:expr) => {
impl Channel<Adc<'static>> for peripherals::$pin {
type ID = u8;
fn channel() -> u8 {
$channel
}
}
};
impl<'d> Adc<'d, Blocking> {
pub fn new_blocking(_inner: impl Peripheral<P = ADC> + 'd, _config: Config) -> Self {
Self::setup();
Self { phantom: PhantomData }
}
}
pub struct InterruptHandler {
@ -158,24 +206,33 @@ pub struct InterruptHandler {
impl interrupt::typelevel::Handler<interrupt::typelevel::ADC_IRQ_FIFO> for InterruptHandler {
unsafe fn on_interrupt() {
let r = Adc::regs();
let r = Adc::<Async>::regs();
r.inte().write(|w| w.set_fifo(false));
WAKER.wake();
}
}
mod sealed {
pub trait AdcPin: crate::gpio::sealed::Pin {
fn channel(&mut self) -> u8;
}
}
pub trait AdcPin: sealed::AdcPin + gpio::Pin {}
macro_rules! impl_pin {
($pin:ident, $channel:expr) => {
impl sealed::AdcPin for peripherals::$pin {
fn channel(&mut self) -> u8 {
$channel
}
}
impl AdcPin for peripherals::$pin {}
};
}
impl_pin!(PIN_26, 0);
impl_pin!(PIN_27, 1);
impl_pin!(PIN_28, 2);
impl_pin!(PIN_29, 3);
impl<WORD, PIN> OneShot<Adc<'static>, WORD, PIN> for Adc<'static>
where
WORD: From<u16>,
PIN: Channel<Adc<'static>, ID = u8> + Pin,
{
type Error = ();
fn read(&mut self, pin: &mut PIN) -> nb::Result<WORD, Self::Error> {
Ok(self.blocking_read(pin).into())
}
}

2
embassy-rp/src/gpio.rs
View File

@ -41,7 +41,7 @@ impl From<Level> for bool {
}
/// Represents a pull setting for an input.
#[derive(Debug, Eq, PartialEq)]
#[derive(Debug, Clone, Copy, Eq, PartialEq)]
pub enum Pull {
None,
Up,