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Introduces a Sequences struct

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This commit is contained in:
huntc 2022-02-04 13:04:55 +11:00
parent bc7266394d
commit 1af6b23f97
2 changed files with 161 additions and 152 deletions
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274
embassy-nrf/src/pwm.rs
View File

@ -31,8 +31,6 @@ pub struct SequencePwm<'d, T: Instance> {
ch1: Option<AnyPin>,
ch2: Option<AnyPin>,
ch3: Option<AnyPin>,
sequence0: Option<Sequence<'d>>,
sequence1: Option<Sequence<'d>>,
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
@ -127,111 +125,9 @@ impl<'d, T: Instance> SequencePwm<'d, T> {
ch1: ch1.degrade_optional(),
ch2: ch2.degrade_optional(),
ch3: ch3.degrade_optional(),
sequence0: None,
sequence1: None,
})
}
/// Start or restart playback. Takes at least one sequence along with its
/// 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<'d>,
sequence1: Option<Sequence<'d>>,
times: SequenceMode,
) -> Result<(), Error> {
let alt_sequence = sequence1.as_ref().unwrap_or(&sequence0);
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);
}
if let SequenceMode::Times(0) = times {
return Err(Error::SequenceTimesAtLeastOne);
}
let _ = self.stop();
let r = T::regs();
r.seq0
.refresh
.write(|w| unsafe { w.bits(sequence0.config.refresh) });
r.seq0
.enddelay
.write(|w| unsafe { w.bits(sequence0.config.end_delay) });
r.seq0
.ptr
.write(|w| unsafe { w.bits(sequence0.words.as_ptr() as u32) });
r.seq0
.cnt
.write(|w| unsafe { w.bits(sequence0.words.len() as u32) });
r.seq1
.refresh
.write(|w| unsafe { w.bits(alt_sequence.config.refresh) });
r.seq1
.enddelay
.write(|w| unsafe { w.bits(alt_sequence.config.end_delay) });
r.seq1
.ptr
.write(|w| unsafe { w.bits(alt_sequence.words.as_ptr() as u32) });
r.seq1
.cnt
.write(|w| unsafe { w.bits(alt_sequence.words.len() as u32) });
r.enable.write(|w| w.enable().enabled());
// defensive before seqstart
compiler_fence(Ordering::SeqCst);
match times {
// just the one time, no loop count
SequenceMode::Times(1) => {
r.loop_.write(|w| w.cnt().disabled());
// tasks_seqstart() doesn't exist in all svds so write its bit instead
r.tasks_seqstart[0].write(|w| unsafe { w.bits(0x01) });
}
// loop count is how many times to play BOTH sequences
// 2 total (1 x 2)
// 3 total, (2 x 2) - 1
SequenceMode::Times(n) => {
let odd = n & 1 == 1;
let times = if odd { (n / 2) + 1 } else { n / 2 };
r.loop_.write(|w| unsafe { w.cnt().bits(times) });
// we can subtract 1 by starting at seq1 instead of seq0
if odd {
// tasks_seqstart() doesn't exist in all svds so write its bit instead
r.tasks_seqstart[1].write(|w| unsafe { w.bits(0x01) });
} else {
// tasks_seqstart() doesn't exist in all svds so write its bit instead
r.tasks_seqstart[0].write(|w| unsafe { w.bits(0x01) });
}
}
// to play infinitely, repeat the sequence one time, then have loops done self trigger seq0 again
SequenceMode::Infinite => {
r.loop_.write(|w| unsafe { w.cnt().bits(0x1) });
r.shorts.write(|w| w.loopsdone_seqstart0().enabled());
// tasks_seqstart() doesn't exist in all svds so write its bit instead
r.tasks_seqstart[0].write(|w| unsafe { w.bits(0x01) });
}
}
self.sequence0 = Some(sequence0);
self.sequence1 = sequence1;
Ok(())
}
/// Returns reference to `Stopped` event endpoint for PPI.
#[inline(always)]
pub fn event_stopped(&self) -> Event {
@ -331,33 +227,12 @@ impl<'d, T: Instance> SequencePwm<'d, T> {
Task::from_reg(&r.tasks_stop)
}
/// Stop playback. Disables the peripheral. Does NOT clear the last duty
/// 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<'d>>, Option<Sequence<'d>>) {
let r = T::regs();
r.shorts.reset();
compiler_fence(Ordering::SeqCst);
// tasks_stop() doesn't exist in all svds so write its bit instead
r.tasks_stop.write(|w| unsafe { w.bits(0x01) });
r.enable.write(|w| w.enable().disabled());
(self.sequence0.take(), self.sequence1.take())
}
}
impl<'a, T: Instance> Drop for SequencePwm<'a, T> {
fn drop(&mut self) {
let r = T::regs();
let _ = self.stop();
if let Some(pin) = &self.ch0 {
pin.set_low();
pin.conf().reset();
@ -426,21 +301,158 @@ impl Default for SequenceConfig {
/// A composition of a sequence buffer and its configuration.
#[non_exhaustive]
pub struct Sequence<'d> {
pub struct Sequence<'s> {
/// The words comprising the sequence. Must not exceed 32767 words.
/// The reason for this buffer to be mutable is so that stopping
/// the PWM can relinquish the sequence for subsequent modification.
pub words: &'d mut [u16],
pub words: &'s [u16],
/// Configuration associated with the sequence.
pub config: SequenceConfig,
}
impl<'d> Sequence<'d> {
pub fn new(words: &'d mut [u16], config: SequenceConfig) -> Self {
impl<'s> Sequence<'s> {
pub fn new(words: &'s [u16], config: SequenceConfig) -> Self {
Self { words, config }
}
}
/// A composition of sequences that can be started and stopped.
/// Takes at least one sequence along with its configuration.
/// Optionally takes a second sequence and its configuration.
/// In the case where no second sequence is provided then the first sequence
/// is used.
#[non_exhaustive]
pub struct Sequences<'d, 's, T: Instance> {
_pwm: &'s mut SequencePwm<'d, T>,
sequence0: Sequence<'s>,
sequence1: Option<Sequence<'s>>,
}
impl<'d, 's, T: Instance> Sequences<'d, 's, T> {
pub fn new(
pwm: &'s mut SequencePwm<'d, T>,
sequence0: Sequence<'s>,
sequence1: Option<Sequence<'s>>,
) -> Self {
Sequences {
_pwm: pwm,
sequence0,
sequence1,
}
}
/// Start or restart playback. The sequence mode applies to both sequences combined as one.
#[inline(always)]
pub fn start(&self, times: SequenceMode) -> Result<(), Error> {
let sequence0 = &self.sequence0;
let alt_sequence = self.sequence1.as_ref().unwrap_or(&self.sequence0);
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);
}
if let SequenceMode::Times(0) = times {
return Err(Error::SequenceTimesAtLeastOne);
}
let _ = self.stop();
let r = T::regs();
r.seq0
.refresh
.write(|w| unsafe { w.bits(sequence0.config.refresh) });
r.seq0
.enddelay
.write(|w| unsafe { w.bits(sequence0.config.end_delay) });
r.seq0
.ptr
.write(|w| unsafe { w.bits(sequence0.words.as_ptr() as u32) });
r.seq0
.cnt
.write(|w| unsafe { w.bits(sequence0.words.len() as u32) });
r.seq1
.refresh
.write(|w| unsafe { w.bits(alt_sequence.config.refresh) });
r.seq1
.enddelay
.write(|w| unsafe { w.bits(alt_sequence.config.end_delay) });
r.seq1
.ptr
.write(|w| unsafe { w.bits(alt_sequence.words.as_ptr() as u32) });
r.seq1
.cnt
.write(|w| unsafe { w.bits(alt_sequence.words.len() as u32) });
r.enable.write(|w| w.enable().enabled());
// defensive before seqstart
compiler_fence(Ordering::SeqCst);
match times {
// just the one time, no loop count
SequenceMode::Times(1) => {
r.loop_.write(|w| w.cnt().disabled());
// tasks_seqstart() doesn't exist in all svds so write its bit instead
r.tasks_seqstart[0].write(|w| unsafe { w.bits(0x01) });
}
// loop count is how many times to play BOTH sequences
// 2 total (1 x 2)
// 3 total, (2 x 2) - 1
SequenceMode::Times(n) => {
let odd = n & 1 == 1;
let times = if odd { (n / 2) + 1 } else { n / 2 };
r.loop_.write(|w| unsafe { w.cnt().bits(times) });
// we can subtract 1 by starting at seq1 instead of seq0
if odd {
// tasks_seqstart() doesn't exist in all svds so write its bit instead
r.tasks_seqstart[1].write(|w| unsafe { w.bits(0x01) });
} else {
// tasks_seqstart() doesn't exist in all svds so write its bit instead
r.tasks_seqstart[0].write(|w| unsafe { w.bits(0x01) });
}
}
// to play infinitely, repeat the sequence one time, then have loops done self trigger seq0 again
SequenceMode::Infinite => {
r.loop_.write(|w| unsafe { w.cnt().bits(0x1) });
r.shorts.write(|w| w.loopsdone_seqstart0().enabled());
// tasks_seqstart() doesn't exist in all svds so write its bit instead
r.tasks_seqstart[0].write(|w| unsafe { w.bits(0x01) });
}
}
Ok(())
}
/// Stop playback. Disables the peripheral. Does NOT clear the last duty
/// cycle from the pin. Returns any sequences previously provided to
/// `start` so that they may be further mutated.
#[inline(always)]
pub fn stop(&self) {
let r = T::regs();
r.shorts.reset();
compiler_fence(Ordering::SeqCst);
// tasks_stop() doesn't exist in all svds so write its bit instead
r.tasks_stop.write(|w| unsafe { w.bits(0x01) });
r.enable.write(|w| w.enable().disabled());
}
}
impl<'d, 's, T: Instance> Drop for Sequences<'d, 's, T> {
fn drop(&mut self) {
let _ = self.stop();
}
}
/// How many times to run the sequence
#[derive(Debug, Eq, PartialEq, Clone, Copy)]
pub enum SequenceMode {

39
examples/nrf/src/bin/pwm_sequence_ws2812b.rs
View File

@ -9,7 +9,7 @@ use embassy::executor::Spawner;
use embassy::time::{Duration, Timer};
use embassy_nrf::gpio::NoPin;
use embassy_nrf::pwm::{
Config, Prescaler, Sequence, SequenceConfig, SequenceLoad, SequenceMode, SequencePwm,
Config, Prescaler, Sequence, SequenceConfig, SequenceLoad, SequenceMode, SequencePwm, Sequences,
};
use embassy_nrf::Peripherals;
@ -30,19 +30,6 @@ 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;
@ -51,18 +38,24 @@ async fn main(_spawner: Spawner, p: Peripherals) {
p.PWM0, p.P1_05, NoPin, NoPin, NoPin, config,
));
unwrap!(pwm.start(color_seq, Some(reset_seq), SequenceMode::Times(2)));
Timer::after(Duration::from_millis(1000)).await;
// Declare the bits of 24 bits in a buffer we'll be
// mutating later.
let mut 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
RES,
];
let mut seq_config = SequenceConfig::default();
seq_config.end_delay = 799; // 50us (20 ticks * 40) - 1 tick because we've already got one RES;
let mut color_bit = 16;
let mut bit_value = T0H;
loop {
if let (Some(color_seq), Some(reset_seq)) = pwm.stop() {
color_seq.words[color_bit] = bit_value;
unwrap!(pwm.start(color_seq, Some(reset_seq), SequenceMode::Times(2)));
}
let sequence0 = Sequence::new(&seq_words, seq_config.clone());
let sequences = Sequences::new(&mut pwm, sequence0, None);
unwrap!(sequences.start(SequenceMode::Times(2)));
Timer::after(Duration::from_millis(50)).await;
@ -79,5 +72,9 @@ async fn main(_spawner: Spawner, p: Peripherals) {
color_bit -= 1;
}
}
drop(sequences);
seq_words[color_bit] = bit_value;
}
}