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-rw-r--r--rust/kernel/lib.rs2
-rw-r--r--rust/kernel/pwm.rs102
2 files changed, 104 insertions, 0 deletions
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 3dd7bebe7888..68c71d888fdb 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -129,6 +129,8 @@ pub mod security;
pub mod seq_file;
pub mod sizes;
mod static_assert;
+#[cfg(CONFIG_RUST_PWM_ABSTRACTIONS)]
+pub mod pwm;
#[doc(hidden)]
pub mod std_vendor;
pub mod str;
diff --git a/rust/kernel/pwm.rs b/rust/kernel/pwm.rs
new file mode 100644
index 000000000000..beabf0086a2f
--- /dev/null
+++ b/rust/kernel/pwm.rs
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2025 Samsung Electronics Co., Ltd.
+// Author: Michal Wilczynski <m.wilczynski@samsung.com>
+
+//! PWM subsystem abstractions.
+//!
+//! C header: [`include/linux/pwm.h`](srctree/include/linux/pwm.h).
+
+use crate::{
+ bindings,
+ prelude::*,
+ types::Opaque,
+};
+use core::convert::TryFrom;
+
+/// PWM polarity. Mirrors [`enum pwm_polarity`](srctree/include/linux/pwm.h).
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub enum Polarity {
+ /// Normal polarity (duty cycle defines the high period of the signal).
+ Normal,
+
+ /// Inversed polarity (duty cycle defines the low period of the signal).
+ Inversed,
+}
+
+impl TryFrom<bindings::pwm_polarity> for Polarity {
+ type Error = Error;
+
+ fn try_from(polarity: bindings::pwm_polarity) -> Result<Self, Error> {
+ match polarity {
+ bindings::pwm_polarity_PWM_POLARITY_NORMAL => Ok(Polarity::Normal),
+ bindings::pwm_polarity_PWM_POLARITY_INVERSED => Ok(Polarity::Inversed),
+ _ => Err(EINVAL),
+ }
+ }
+}
+
+impl From<Polarity> for bindings::pwm_polarity {
+ fn from(polarity: Polarity) -> Self {
+ match polarity {
+ Polarity::Normal => bindings::pwm_polarity_PWM_POLARITY_NORMAL,
+ Polarity::Inversed => bindings::pwm_polarity_PWM_POLARITY_INVERSED,
+ }
+ }
+}
+
+/// Represents a PWM waveform configuration.
+/// Mirrors struct [`struct pwm_waveform`](srctree/include/linux/pwm.h).
+#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]
+pub struct Waveform {
+ /// Total duration of one complete PWM cycle, in nanoseconds.
+ pub period_length_ns: u64,
+
+ /// Duty-cycle active time, in nanoseconds.
+ ///
+ /// For a typical normal polarity configuration (active-high) this is the
+ /// high time of the signal.
+ pub duty_length_ns: u64,
+
+ /// Duty-cycle start offset, in nanoseconds.
+ ///
+ /// Delay from the beginning of the period to the first active edge.
+ /// In most simple PWM setups this is `0`, so the duty cycle starts
+ /// immediately at each period’s start.
+ pub duty_offset_ns: u64,
+}
+
+impl From<bindings::pwm_waveform> for Waveform {
+ fn from(wf: bindings::pwm_waveform) -> Self {
+ Waveform {
+ period_length_ns: wf.period_length_ns,
+ duty_length_ns: wf.duty_length_ns,
+ duty_offset_ns: wf.duty_offset_ns,
+ }
+ }
+}
+
+impl From<Waveform> for bindings::pwm_waveform {
+ fn from(wf: Waveform) -> Self {
+ bindings::pwm_waveform {
+ period_length_ns: wf.period_length_ns,
+ duty_length_ns: wf.duty_length_ns,
+ duty_offset_ns: wf.duty_offset_ns,
+ }
+ }
+}
+
+/// Wrapper for PWM state [`struct pwm_state`](srctree/include/linux/pwm.h).
+#[repr(transparent)]
+pub struct State(bindings::pwm_state);
+
+impl State {
+ /// Creates a `State` wrapper by taking ownership of a C `pwm_state` value.
+ pub(crate) fn from_c(c_state: bindings::pwm_state) -> Self {
+ State(c_state)
+ }
+
+ /// Returns `true` if the PWM signal is enabled.
+ pub fn enabled(&self) -> bool {
+ self.0.enabled
+ }
+}