This commit allows event_endtx to be used outside of the Uarte itself. As a consequence, PPI can be used to drive tasks given the end of transmission on the Uarte. This is particularly useful for situations like RS485 where a GPIO must be set to high when transmitting then cleared when done. A non-ppi approach can cause a delay in the clearing of this GPIO as other Embassy tasks might become scheduled.
Unsafe is not required here given that all futures are required to live longer than their global peripheral instances. There are other occurrences of unsafe being used on new that should be removed. I started to do that but then went down a bit of a rabbit hole.
544: Introduces split on the nRF Uarte r=Dirbaio a=huntc
A new `split` method is introduced such that the Uarte tx and rx can be used from separate tasks. An MPSC is used in an example to illustrate how data may be passed between these tasks.
The approach taken within the `Uarte` struct is to split into tx and rx fields on calling `Uarte::new`. These fields are returned given a call to `Uarte::split`, but otherwise, if that call isn't made, then the API remains as it was before.
Here's a snippet from a new example introduced:
```rust
#[embassy::main]
async fn main(spawner: Spawner, p: Peripherals) {
// ...
let uart = uarte::Uarte::new(p.UARTE0, irq, p.P0_08, p.P0_06, NoPin, NoPin, config);
let (mut tx, rx) = uart.split();
// ...
// Spawn a task responsible purely for reading
unwrap!(spawner.spawn(reader(rx, s)));
// ...
// Continue reading in this main task and write
// back out the buffer we receive from the read
// task.
loop {
if let Some(buf) = r.recv().await {
info!("writing...");
unwrap!(tx.write(&buf).await);
}
}
}
#[embassy::task]
async fn reader(mut rx: UarteRx<'static, UARTE0>, s: Sender<'static, Noop, [u8; 8], 1>) {
let mut buf = [0; 8];
loop {
info!("reading...");
unwrap!(rx.read(&mut buf).await);
unwrap!(s.send(buf).await);
}
}
```
Co-authored-by: huntc <huntchr@gmail.com>
A new `split` method is introduced such that the Uarte tx and rx can be used from separate tasks. An MPSC is used to illustrate how data may be passed between these tasks.
542: nrf/gpiote: remove PortInput, move impls to Input/FlexPin. r=Dirbaio a=Dirbaio
`PortInput` is just a dumb wrapper around `Input`, it has no reason whatsoever to exist. This PR moves the `wait_for_x` functionality to `Input` directly.
It also adds it to `FlexPin` for completeness and consistency with `Input`.
(The reason `PortInput` exists is a while ago `GPIOTE` was an owned singleton that you had to initialize, so `PortInput::new()` would require it to enforce it's been initialized. This doesn't apply anymore now that GPIOTE is "global")
Co-authored-by: Dario Nieuwenhuis <dirbaio@dirbaio.net>
As per Tokio and others, this commit provides a `poll_flush` method on `AsyncWrite` so that a best-effort attempt at wakening once all bytes are flushed can be made.
The constructors themselves are not strictly unsafe. Interactions with DMA can be generally unsafe if a future is dropped, but that's a separate issue. It is important that we use the `unsafe` keyword diligently as it can lead to confusion otherwise.
486: Pwm ppi events r=Dirbaio a=jacobrosenthal
More PWM yak shaving. I was going to do some safe pwm ppi events stuff but I just dont think it fits this api design.. ppi is just very low level, im not sure how safe it will be in general
* first we should probably have borrows of handlers for ppi with lifetime of the peripheral? hal does eb4ba6ae42/nrf-hal-common/src/pwm.rs (L714-L716)
* in general having access to tasks can put the state in some configuration the api doesnt understand anymore. for `SequencePwm` ideally id hand you back either only seq_start0 or seq_start1 because youd only use one based on if your `Times` is even or odd.. but again we only know that with this api AFTER start has been called. I dont think were ready for typestates
SO I figured why not add the pwm ppi events but make them unsafe and commit this example since I started it.
Somewhat related drop IS removing the last duty cycle from the pin correctly, but stop DOES NOT..the only thing that sets the pin back is pin.conf() as far as I can tell, so I tried to document that better and got rid of stop for the `SimplePwm` again since that doesnt need it then. However its ackward we dont have a way to unset the pwm without setting a new sequence of 0s, or dropping the peripheral
Co-authored-by: Jacob Rosenthal <jacobrosenthal@gmail.com>
