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Revert "Own the sequence buffer"

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This reverts commit 482389a691.
This commit is contained in:
huntc 2022-01-30 16:21:23 +11:00
parent 482389a691
commit 1c67bd4643
4 changed files with 68 additions and 108 deletions
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108
embassy-nrf/src/pwm.rs
View File

@ -25,14 +25,14 @@ pub struct SimplePwm<'d, T: Instance> {
/// SequencePwm allows you to offload the updating of a sequence of duty cycles
/// to up to four channels, as well as repeat that sequence n times.
pub struct SequencePwm<'d, T: Instance, const S0: usize, const S1: usize> {
pub struct SequencePwm<'d, T: Instance> {
phantom: PhantomData<&'d mut T>,
ch0: Option<AnyPin>,
ch1: Option<AnyPin>,
ch2: Option<AnyPin>,
ch3: Option<AnyPin>,
sequence0: Option<Sequence<S0>>,
sequence1: Option<Sequence<S1>>,
sequence0: Option<Sequence<'d>>,
sequence1: Option<Sequence<'d>>,
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
@ -43,17 +43,13 @@ pub enum Error {
SequenceTooLong,
/// Min Sequence count is 1
SequenceTimesAtLeastOne,
/// Sequence 0 is required, Sequence 1 is NOT required
SequenceTimesRequireSeq0Only,
/// Sequence 0 is required, Sequence 1 is required
SequenceTimesRequireBothSeq0AndSeq1,
/// EasyDMA can only read from data memory, read only buffers in flash will fail.
DMABufferNotInDataMemory,
}
const MAX_SEQUENCE_LEN: usize = 32767;
impl<'d, T: Instance, const S0: usize, const S1: usize> SequencePwm<'d, T, S0, S1> {
impl<'d, T: Instance> SequencePwm<'d, T> {
/// Creates the interface to a `SequencePwm`.
///
/// Must be started by calling `start`
@ -72,10 +68,6 @@ impl<'d, T: Instance, const S0: usize, const S1: usize> SequencePwm<'d, T, S0, S
ch3: impl Unborrow<Target = impl GpioOptionalPin> + 'd,
config: Config,
) -> Result<Self, Error> {
if S0 > MAX_SEQUENCE_LEN || S1 > MAX_SEQUENCE_LEN {
return Err(Error::SequenceTooLong);
}
unborrow!(ch0, ch1, ch2, ch3);
let r = T::regs();
@ -141,49 +133,31 @@ impl<'d, T: Instance, const S0: usize, const S1: usize> SequencePwm<'d, T, S0, S
}
/// Start or restart playback. Takes at least one sequence along with its
/// configuration. A second sequence must be provided when looping i.e.
/// when the sequence mode is anything other than Times(1).
/// configuration. Optionally takes a second sequence and its configuration.
/// In the case where no second sequence is provided then the first sequence
/// is used. The sequence mode applies to both sequences combined as one.
#[inline(always)]
pub fn start(
&mut self,
sequence0: Sequence<S0>,
sequence1: Sequence<S1>,
sequence0: Sequence<'d>,
sequence1: Option<Sequence<'d>>,
times: SequenceMode,
) -> Result<(), Error> {
slice_in_ram_or(&sequence0.words, Error::DMABufferNotInDataMemory)?;
slice_in_ram_or(&sequence1.words, Error::DMABufferNotInDataMemory)?;
let alt_sequence = sequence1.as_ref().unwrap_or(&sequence0);
let seq_0_word_count = sequence0.word_count.unwrap_or(S0);
let seq_1_word_count = sequence0.word_count.unwrap_or(S1);
if seq_0_word_count > S0 || seq_1_word_count > S1 {
slice_in_ram_or(sequence0.words, Error::DMABufferNotInDataMemory)?;
slice_in_ram_or(alt_sequence.words, Error::DMABufferNotInDataMemory)?;
if sequence0.words.len() > MAX_SEQUENCE_LEN || alt_sequence.words.len() > MAX_SEQUENCE_LEN {
return Err(Error::SequenceTooLong);
}
match times {
SequenceMode::Times(0) => return Err(Error::SequenceTimesAtLeastOne),
SequenceMode::Times(1) if seq_0_word_count == 0 || seq_1_word_count != 0 => {
return Err(Error::SequenceTimesRequireSeq0Only)
}
SequenceMode::Times(1) => (),
SequenceMode::Times(_) | SequenceMode::Infinite
if seq_0_word_count == 0 || seq_1_word_count == 0 =>
{
return Err(Error::SequenceTimesRequireBothSeq0AndSeq1)
}
SequenceMode::Times(_) | SequenceMode::Infinite => (),
if let SequenceMode::Times(0) = times {
return Err(Error::SequenceTimesAtLeastOne);
}
let _ = self.stop();
// We now own these sequences and they will be moved. We want
// the peripheral to point at the right bits of memory hence
// moving the sequences early.
self.sequence0 = Some(sequence0);
self.sequence1 = Some(sequence1);
let sequence0 = self.sequence0.as_ref().unwrap();
let sequence1 = self.sequence1.as_ref().unwrap();
let r = T::regs();
r.seq0
@ -197,20 +171,20 @@ impl<'d, T: Instance, const S0: usize, const S1: usize> SequencePwm<'d, T, S0, S
.write(|w| unsafe { w.bits(sequence0.words.as_ptr() as u32) });
r.seq0
.cnt
.write(|w| unsafe { w.bits(seq_0_word_count as u32) });
.write(|w| unsafe { w.bits(sequence0.words.len() as u32) });
r.seq1
.refresh
.write(|w| unsafe { w.bits(sequence1.config.refresh) });
.write(|w| unsafe { w.bits(alt_sequence.config.refresh) });
r.seq1
.enddelay
.write(|w| unsafe { w.bits(sequence1.config.end_delay) });
.write(|w| unsafe { w.bits(alt_sequence.config.end_delay) });
r.seq1
.ptr
.write(|w| unsafe { w.bits(sequence1.words.as_ptr() as u32) });
.write(|w| unsafe { w.bits(alt_sequence.words.as_ptr() as u32) });
r.seq1
.cnt
.write(|w| unsafe { w.bits(seq_1_word_count as u32) });
.write(|w| unsafe { w.bits(alt_sequence.words.len() as u32) });
r.enable.write(|w| w.enable().enabled());
@ -252,6 +226,9 @@ impl<'d, T: Instance, const S0: usize, const S1: usize> SequencePwm<'d, T, S0, S
}
}
self.sequence0 = Some(sequence0);
self.sequence1 = sequence1;
Ok(())
}
@ -359,7 +336,7 @@ impl<'d, T: Instance, const S0: usize, const S1: usize> SequencePwm<'d, T, S0, S
/// cycle from the pin. Returns any sequences previously provided to
/// `start` so that they may be further mutated.
#[inline(always)]
pub fn stop(&mut self) -> (Option<Sequence<S0>>, Option<Sequence<S1>>) {
pub fn stop(&mut self) -> (Option<Sequence<'d>>, Option<Sequence<'d>>) {
let r = T::regs();
r.shorts.reset();
@ -375,7 +352,7 @@ impl<'d, T: Instance, const S0: usize, const S1: usize> SequencePwm<'d, T, S0, S
}
}
impl<'a, T: Instance, const S0: usize, const S1: usize> Drop for SequencePwm<'a, T, S0, S1> {
impl<'a, T: Instance> Drop for SequencePwm<'a, T> {
fn drop(&mut self) {
let r = T::regs();
@ -404,7 +381,6 @@ impl<'a, T: Instance, const S0: usize, const S1: usize> Drop for SequencePwm<'a,
}
}
/// Configuration for the PWM as a whole.
#[non_exhaustive]
pub struct Config {
/// Selects up mode or up-and-down mode for the counter
@ -428,7 +404,6 @@ impl Default for Config {
}
}
/// Configuration per sequence
#[non_exhaustive]
#[derive(Clone)]
pub struct SequenceConfig {
@ -447,38 +422,19 @@ impl Default for SequenceConfig {
}
}
/// A composition of a sequence buffer and its configuration.
#[non_exhaustive]
#[derive(Clone)]
pub struct Sequence<const S: usize> {
pub struct Sequence<'d> {
/// The words comprising the sequence. Must not exceed 32767 words.
pub words: [u16; S],
/// The count of words to use. If None the S will be used.
pub word_count: Option<usize>,
pub words: &'d mut [u16],
/// Configuration associated with the sequence.
pub config: SequenceConfig,
}
impl<const S: usize> Sequence<S> {
pub const fn new(words: [u16; S], config: SequenceConfig) -> Self {
Self {
words,
word_count: None,
config,
impl<'d> Sequence<'d> {
pub fn new(words: &'d mut [u16], config: SequenceConfig) -> Self {
Self { words, config }
}
}
}
/// Declares an empty sequence which will cause it to be disabled.
/// Note that any looping i.e. !Times(1), will require a second
/// sequence given the way the PWM peripheral works.
pub const EMPTY_SEQ: Sequence<0> = Sequence::new(
[],
SequenceConfig {
refresh: 0,
end_delay: 0,
},
);
/// How many times to run the sequence
#[derive(Debug, Eq, PartialEq, Clone, Copy)]
@ -490,7 +446,7 @@ pub enum SequenceMode {
/// 5 to 6 = Run sequence 0, sequence 1, sequence 0, sequence 1, sequence 0 and then sequence 1
/// i.e the when >= 2 the loop count is determined by dividing by 2 and rounding up
Times(u16),
/// Repeat until `stop` is called. Both sequences must be provided.
/// Repeat until `stop` is called.
Infinite,
}

22
examples/nrf/src/bin/pwm_sequence.rs
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@ -8,13 +8,14 @@ use defmt::*;
use embassy::executor::Spawner;
use embassy::time::{Duration, Timer};
use embassy_nrf::gpio::NoPin;
use embassy_nrf::pwm::{
Config, Prescaler, Sequence, SequenceConfig, SequenceMode, SequencePwm, EMPTY_SEQ,
};
use embassy_nrf::pwm::{Config, Prescaler, Sequence, SequenceConfig, SequenceMode, SequencePwm};
use embassy_nrf::Peripherals;
#[embassy::main]
async fn main(_spawner: Spawner, p: Peripherals) {
let mut seq_words_1: [u16; 5] = [1000, 250, 100, 50, 0];
let mut seq_words_2: [u16; 5] = [0, 50, 100, 250, 1000];
let mut config = Config::default();
config.prescaler = Prescaler::Div128;
// 1 period is 1000 * (128/16mhz = 0.000008s = 0.008ms) = 8us
@ -25,20 +26,25 @@ async fn main(_spawner: Spawner, p: Peripherals) {
seq_config.refresh = 624;
// thus our sequence takes 5 * 5000ms or 25 seconds
let seq_1 = Sequence::new([1000, 250, 100, 50, 0], seq_config.clone());
let seq_2 = Sequence::new([0, 50, 100, 250, 1000], seq_config);
let mut pwm = unwrap!(SequencePwm::new(
p.PWM0, p.P0_13, NoPin, NoPin, NoPin, config,
));
unwrap!(pwm.start(seq_1, EMPTY_SEQ, SequenceMode::Times(1)));
let _ = pwm.start(
Sequence::new(&mut seq_words_1, seq_config.clone()),
None,
SequenceMode::Infinite,
);
info!("pwm started!");
Timer::after(Duration::from_millis(20000)).await;
info!("pwm starting with another sequence!");
unwrap!(pwm.start(seq_2, EMPTY_SEQ, SequenceMode::Times(1)));
let _ = pwm.start(
Sequence::new(&mut seq_words_2, seq_config),
None,
SequenceMode::Infinite,
);
// we can abort a sequence if we need to before its complete with pwm.stop()
// or stop is also implicitly called when the pwm peripheral is dropped

13
examples/nrf/src/bin/pwm_sequence_ppi.rs
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@ -16,7 +16,7 @@ use embassy_nrf::Peripherals;
#[embassy::main]
async fn main(_spawner: Spawner, p: Peripherals) {
let seq_words: [u16; 5] = [1000, 250, 100, 50, 0];
let mut seq_words: [u16; 5] = [1000, 250, 100, 50, 0];
let mut config = Config::default();
config.prescaler = Prescaler::Div128;
@ -31,12 +31,11 @@ async fn main(_spawner: Spawner, p: Peripherals) {
p.PWM0, p.P0_13, NoPin, NoPin, NoPin, config,
));
// If we loop in any way i.e. not Times(1), then we must provide
// the PWM peripheral with two sequences.
let seq_0 = Sequence::new(seq_words, seq_config);
let seq_1 = seq_0.clone();
unwrap!(pwm.start(seq_0, seq_1, SequenceMode::Infinite));
let _ = pwm.start(
Sequence::new(&mut seq_words, seq_config),
None,
SequenceMode::Infinite,
);
// pwm.stop() deconfigures pins, and then the task_start_seq0 task cant work
// so its going to have to start running in order load the configuration

33
examples/nrf/src/bin/pwm_sequence_ws2812b.rs
View File

@ -30,6 +30,19 @@ const RES: u16 = 0x8000;
// line is assumed to be P1_05.
#[embassy::main]
async fn main(_spawner: Spawner, p: Peripherals) {
// Declare the bits of 24 bits
let mut color_seq_words = [
T0H, T0H, T0H, T0H, T0H, T0H, T0H, T0H, // G
T0H, T0H, T0H, T0H, T0H, T0H, T0H, T0H, // R
T1H, T1H, T1H, T1H, T1H, T1H, T1H, T1H, // B
];
let color_seq = Sequence::new(&mut color_seq_words, SequenceConfig::default());
let mut reset_seq_words = [RES; 1];
let mut reset_seq_config = SequenceConfig::default();
reset_seq_config.end_delay = 799; // 50us (20 ticks * 40) - 1 tick because we've already got one RES;
let reset_seq = Sequence::new(&mut reset_seq_words, reset_seq_config);
let mut config = Config::default();
config.sequence_load = SequenceLoad::Common;
config.prescaler = Prescaler::Div1;
@ -38,21 +51,7 @@ async fn main(_spawner: Spawner, p: Peripherals) {
p.PWM0, p.P1_05, NoPin, NoPin, NoPin, config,
));
// Declare the bits of 24 bits
let color_seq = Sequence::new(
[
T0H, T0H, T0H, T0H, T0H, T0H, T0H, T0H, // G
T0H, T0H, T0H, T0H, T0H, T0H, T0H, T0H, // R
T1H, T1H, T1H, T1H, T1H, T1H, T1H, T1H, // B
],
SequenceConfig::default(),
);
let mut reset_seq_config = SequenceConfig::default();
reset_seq_config.end_delay = 799; // 50us (20 ticks * 40) - 1 tick because we've already got one RES;
let reset_seq = Sequence::new([RES], reset_seq_config);
unwrap!(pwm.start(color_seq, reset_seq, SequenceMode::Times(2)));
unwrap!(pwm.start(color_seq, Some(reset_seq), SequenceMode::Times(2)));
Timer::after(Duration::from_millis(1000)).await;
@ -60,9 +59,9 @@ async fn main(_spawner: Spawner, p: Peripherals) {
let mut bit_value = T0H;
loop {
if let (Some(mut color_seq), Some(reset_seq)) = pwm.stop() {
if let (Some(color_seq), Some(reset_seq)) = pwm.stop() {
color_seq.words[color_bit] = bit_value;
unwrap!(pwm.start(color_seq, reset_seq, SequenceMode::Times(2)));
unwrap!(pwm.start(color_seq, Some(reset_seq), SequenceMode::Times(2)));
}
Timer::after(Duration::from_millis(50)).await;