From ec66fcd01a9dd4e7a9d7b2e6c7dfcf92f9c9901d Mon Sep 17 00:00:00 2001
From: Jacob Rosenthal <jacobrosenthal@gmail.com>
Date: Thu, 11 Nov 2021 19:14:07 -0700
Subject: [PATCH] pwm_sequence consume buffer

---
 embassy-nrf/src/pwm.rs               | 18 ++++++++----------
 examples/nrf/src/bin/pwm_sequence.rs |  8 +-------
 2 files changed, 9 insertions(+), 17 deletions(-)

diff --git a/embassy-nrf/src/pwm.rs b/embassy-nrf/src/pwm.rs
index 08e9add0..64262067 100644
--- a/embassy-nrf/src/pwm.rs
+++ b/embassy-nrf/src/pwm.rs
@@ -24,7 +24,7 @@ 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> {
+pub struct SequencePwm<'d, T: Instance, const N: usize> {
     phantom: PhantomData<&'d mut T>,
     ch0: Option<AnyPin>,
     ch1: Option<AnyPin>,
@@ -44,7 +44,7 @@ pub enum Error {
     DMABufferNotInDataMemory,
 }
 
-impl<'d, T: Instance> SequencePwm<'d, T> {
+impl<'d, T: Instance, const N: usize> SequencePwm<'d, T, N> {
     /// Creates the interface to a `SequencePwm`.
     ///
     /// Must be started by calling `start`
@@ -55,18 +55,18 @@ impl<'d, T: Instance> SequencePwm<'d, T> {
     /// mechanisms) on stack allocated buffers which which have been passed to
     /// [`new()`](SequencePwm::new).
     #[allow(unused_unsafe)]
-    pub fn new<'a>(
+    pub fn new(
         _pwm: impl Unborrow<Target = T> + 'd,
         ch0: impl Unborrow<Target = impl GpioOptionalPin> + 'd,
         ch1: impl Unborrow<Target = impl GpioOptionalPin> + 'd,
         ch2: impl Unborrow<Target = impl GpioOptionalPin> + 'd,
         ch3: impl Unborrow<Target = impl GpioOptionalPin> + 'd,
         config: SequenceConfig,
-        sequence: &'a [u16],
+        sequence: [u16; N],
     ) -> Result<Self, Error> {
-        slice_in_ram_or(sequence, Error::DMABufferNotInDataMemory)?;
+        slice_in_ram_or(&sequence, Error::DMABufferNotInDataMemory)?;
 
-        if sequence.len() > 32767 {
+        if N > 32767 {
             return Err(Error::SequenceTooLong);
         }
 
@@ -108,9 +108,7 @@ impl<'d, T: Instance> SequencePwm<'d, T> {
         r.seq0
             .ptr
             .write(|w| unsafe { w.bits(sequence.as_ptr() as u32) });
-        r.seq0
-            .cnt
-            .write(|w| unsafe { w.bits(sequence.len() as u32) });
+        r.seq0.cnt.write(|w| unsafe { w.bits(N as u32) });
         r.seq0.refresh.write(|w| unsafe { w.bits(config.refresh) });
         r.seq0
             .enddelay
@@ -224,7 +222,7 @@ impl<'d, T: Instance> SequencePwm<'d, T> {
     }
 }
 
-impl<'a, T: Instance> Drop for SequencePwm<'a, T> {
+impl<'a, T: Instance, const N: usize> Drop for SequencePwm<'a, T, N> {
     fn drop(&mut self) {
         let r = T::regs();
 
diff --git a/examples/nrf/src/bin/pwm_sequence.rs b/examples/nrf/src/bin/pwm_sequence.rs
index d02b0c9c..2b8a3a7d 100644
--- a/examples/nrf/src/bin/pwm_sequence.rs
+++ b/examples/nrf/src/bin/pwm_sequence.rs
@@ -98,13 +98,7 @@ async fn main(_spawner: Spawner, p: Peripherals) {
     config.refresh = 3;
 
     let pwm = unwrap!(SequencePwm::new(
-        p.PWM0,
-        p.P0_13,
-        NoPin,
-        NoPin,
-        NoPin,
-        config,
-        &seq_values
+        p.PWM0, p.P0_13, NoPin, NoPin, NoPin, config, seq_values
     ));
     let _ = pwm.start(SequenceMode::Infinite);
     info!("pwm started!");