embassy_stm32/lptim/
pwm.rs

1//! PWM driver.
2
3use core::marker::PhantomData;
4
5use embassy_hal_internal::{into_ref, PeripheralRef};
6
7use super::timer::Timer;
8#[cfg(not(any(lptim_v2a, lptim_v2b)))]
9use super::OutputPin;
10#[cfg(any(lptim_v2a, lptim_v2b))]
11use super::{channel::Channel, timer::ChannelDirection, Channel1Pin, Channel2Pin};
12use super::{BasicInstance, Instance};
13use crate::gpio::{AfType, AnyPin, OutputType, Speed};
14use crate::time::Hertz;
15use crate::Peripheral;
16
17/// Output marker type.
18pub enum Output {}
19/// Channel 1 marker type.
20pub enum Ch1 {}
21/// Channel 2 marker type.
22pub enum Ch2 {}
23
24/// PWM pin wrapper.
25///
26/// This wraps a pin to make it usable with PWM.
27pub struct PwmPin<'d, T, C> {
28    _pin: PeripheralRef<'d, AnyPin>,
29    phantom: PhantomData<(T, C)>,
30}
31
32macro_rules! channel_impl {
33    ($new_chx:ident, $channel:ident, $pin_trait:ident) => {
34        impl<'d, T: BasicInstance> PwmPin<'d, T, $channel> {
35            #[doc = concat!("Create a new ", stringify!($channel), " PWM pin instance.")]
36            pub fn $new_chx(pin: impl Peripheral<P = impl $pin_trait<T>> + 'd) -> Self {
37                into_ref!(pin);
38                critical_section::with(|_| {
39                    pin.set_low();
40                    pin.set_as_af(
41                        pin.af_num(),
42                        AfType::output(OutputType::PushPull, Speed::VeryHigh),
43                    );
44                });
45                PwmPin {
46                    _pin: pin.map_into(),
47                    phantom: PhantomData,
48                }
49            }
50        }
51    };
52}
53
54#[cfg(not(any(lptim_v2a, lptim_v2b)))]
55channel_impl!(new, Output, OutputPin);
56#[cfg(any(lptim_v2a, lptim_v2b))]
57channel_impl!(new_ch1, Ch1, Channel1Pin);
58#[cfg(any(lptim_v2a, lptim_v2b))]
59channel_impl!(new_ch2, Ch2, Channel2Pin);
60
61/// PWM driver.
62pub struct Pwm<'d, T: Instance> {
63    inner: Timer<'d, T>,
64}
65
66#[cfg(not(any(lptim_v2a, lptim_v2b)))]
67impl<'d, T: Instance> Pwm<'d, T> {
68    /// Create a new PWM driver.
69    pub fn new(tim: impl Peripheral<P = T> + 'd, _output_pin: PwmPin<'d, T, Output>, freq: Hertz) -> Self {
70        Self::new_inner(tim, freq)
71    }
72
73    /// Set the duty.
74    ///
75    /// The value ranges from 0 for 0% duty, to [`get_max_duty`](Self::get_max_duty) for 100% duty, both included.
76    pub fn set_duty(&mut self, duty: u16) {
77        assert!(duty <= self.get_max_duty());
78        self.inner.set_compare_value(duty)
79    }
80
81    /// Get the duty.
82    ///
83    /// The value ranges from 0 for 0% duty, to [`get_max_duty`](Self::get_max_duty) for 100% duty, both included.
84    pub fn get_duty(&self) -> u16 {
85        self.inner.get_compare_value()
86    }
87
88    fn post_init(&mut self) {}
89}
90
91#[cfg(any(lptim_v2a, lptim_v2b))]
92impl<'d, T: Instance> Pwm<'d, T> {
93    /// Create a new PWM driver.
94    pub fn new(
95        tim: impl Peripheral<P = T> + 'd,
96        _ch1_pin: Option<PwmPin<'d, T, Ch1>>,
97        _ch2_pin: Option<PwmPin<'d, T, Ch2>>,
98        freq: Hertz,
99    ) -> Self {
100        Self::new_inner(tim, freq)
101    }
102
103    /// Enable the given channel.
104    pub fn enable(&mut self, channel: Channel) {
105        self.inner.enable_channel(channel, true);
106    }
107
108    /// Disable the given channel.
109    pub fn disable(&mut self, channel: Channel) {
110        self.inner.enable_channel(channel, false);
111    }
112
113    /// Check whether given channel is enabled
114    pub fn is_enabled(&self, channel: Channel) -> bool {
115        self.inner.get_channel_enable_state(channel)
116    }
117
118    /// Set the duty for a given channel.
119    ///
120    /// The value ranges from 0 for 0% duty, to [`get_max_duty`](Self::get_max_duty) for 100% duty, both included.
121    pub fn set_duty(&mut self, channel: Channel, duty: u16) {
122        assert!(duty <= self.get_max_duty());
123        self.inner.set_compare_value(channel, duty)
124    }
125
126    /// Get the duty for a given channel.
127    ///
128    /// The value ranges from 0 for 0% duty, to [`get_max_duty`](Self::get_max_duty) for 100% duty, both included.
129    pub fn get_duty(&self, channel: Channel) -> u16 {
130        self.inner.get_compare_value(channel)
131    }
132
133    fn post_init(&mut self) {
134        [Channel::Ch1, Channel::Ch2].iter().for_each(|&channel| {
135            self.inner.set_channel_direction(channel, ChannelDirection::OutputPwm);
136        });
137    }
138}
139
140impl<'d, T: Instance> Pwm<'d, T> {
141    fn new_inner(tim: impl Peripheral<P = T> + 'd, freq: Hertz) -> Self {
142        let mut this = Self { inner: Timer::new(tim) };
143
144        this.inner.enable();
145        this.set_frequency(freq);
146
147        this.post_init();
148
149        this.inner.continuous_mode_start();
150
151        this
152    }
153
154    /// Set PWM frequency.
155    ///
156    /// Note: when you call this, the max duty value changes, so you will have to
157    /// call `set_duty` on all channels with the duty calculated based on the new max duty.
158    pub fn set_frequency(&mut self, frequency: Hertz) {
159        self.inner.set_frequency(frequency);
160    }
161
162    /// Get max duty value.
163    ///
164    /// This value depends on the configured frequency and the timer's clock rate from RCC.
165    pub fn get_max_duty(&self) -> u16 {
166        self.inner.get_max_compare_value() + 1
167    }
168}
embassy_stm32/lptim/pwm.rs

embassy_stm32/lptim/
pwm.rs
