embassy/embassy-rp/src/adc.rs
Lachezar Lechev 5cb0c8cc01
fix: rp - disable Pull-down/up resistors for ADC read
Signed-off-by: Lachezar Lechev <elpiel93@gmail.com>
2023-02-28 09:22:38 +02:00

183 lines
4.8 KiB
Rust

use core::future::poll_fn;
use core::marker::PhantomData;
use core::sync::atomic::{compiler_fence, Ordering};
use core::task::Poll;
use embassy_hal_common::into_ref;
use embassy_sync::waitqueue::AtomicWaker;
use embedded_hal_02::adc::{Channel, OneShot};
use crate::gpio::Pin;
use crate::interrupt::{self, InterruptExt};
use crate::peripherals::ADC;
use crate::{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
}
#[non_exhaustive]
pub struct Config {}
impl Default for Config {
fn default() -> Self {
Self {}
}
}
pub struct Adc<'d> {
phantom: PhantomData<&'d ADC>,
}
impl<'d> Adc<'d> {
#[inline]
fn regs() -> pac::adc::Adc {
pac::ADC
}
#[inline]
fn reset() -> pac::resets::regs::Peripherals {
let mut ret = pac::resets::regs::Peripherals::default();
ret.set_adc(true);
ret
}
pub fn new(
_inner: impl Peripheral<P = ADC> + 'd,
irq: impl Peripheral<P = interrupt::ADC_IRQ_FIFO> + 'd,
_config: Config,
) -> Self {
into_ref!(irq);
unsafe {
let reset = Self::reset();
crate::reset::reset(reset);
crate::reset::unreset_wait(reset);
let r = Self::regs();
// Enable ADC
r.cs().write(|w| w.set_en(true));
// Wait for ADC ready
while !r.cs().read().ready() {}
}
// Setup IRQ
irq.disable();
irq.set_handler(|_| unsafe {
let r = Self::regs();
r.inte().write(|w| w.set_fifo(false));
WAKER.wake();
});
irq.unpend();
irq.enable();
Self { phantom: PhantomData }
}
async fn wait_for_ready() {
let r = Self::regs();
unsafe {
r.inte().write(|w| w.set_fifo(true));
compiler_fence(Ordering::SeqCst);
poll_fn(|cx| {
WAKER.register(cx.waker());
if r.cs().read().ready() {
return Poll::Ready(());
}
Poll::Pending
})
.await;
}
}
pub async fn read<PIN: Channel<Adc<'d>, ID = u8> + Pin>(&mut self, pin: &mut PIN) -> u16 {
let r = Self::regs();
unsafe {
// 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)
});
Self::wait_for_ready().await;
r.result().read().result().into()
}
}
pub async fn read_temperature(&mut self) -> u16 {
let r = Self::regs();
unsafe {
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>>(&mut self, _pin: &mut PIN) -> u16 {
let r = Self::regs();
unsafe {
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();
unsafe {
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()
}
}
}
macro_rules! impl_pin {
($pin:ident, $channel:expr) => {
impl Channel<Adc<'static>> for peripherals::$pin {
type ID = u8;
fn channel() -> u8 {
$channel
}
}
};
}
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>,
{
type Error = ();
fn read(&mut self, pin: &mut PIN) -> nb::Result<WORD, Self::Error> {
Ok(self.blocking_read(pin).into())
}
}