embassy_stm32/lptim/timer/
mod.rs

1//! Low-level timer driver.
2mod prescaler;
3
4use embassy_hal_internal::{into_ref, Peripheral, PeripheralRef};
5
6#[cfg(any(lptim_v2a, lptim_v2b))]
7use super::channel::Channel;
8#[cfg(any(lptim_v2a, lptim_v2b))]
9mod channel_direction;
10#[cfg(any(lptim_v2a, lptim_v2b))]
11pub use channel_direction::ChannelDirection;
12use prescaler::Prescaler;
13
14use super::Instance;
15use crate::rcc;
16use crate::time::Hertz;
17
18/// Low-level timer driver.
19pub struct Timer<'d, T: Instance> {
20    _tim: PeripheralRef<'d, T>,
21}
22
23impl<'d, T: Instance> Timer<'d, T> {
24    /// Create a new timer driver.
25    pub fn new(tim: impl Peripheral<P = T> + 'd) -> Self {
26        into_ref!(tim);
27
28        rcc::enable_and_reset::<T>();
29
30        Self { _tim: tim }
31    }
32
33    /// Enable the timer.
34    pub fn enable(&self) {
35        T::regs().cr().modify(|w| w.set_enable(true));
36    }
37
38    /// Disable the timer.
39    pub fn disable(&self) {
40        T::regs().cr().modify(|w| w.set_enable(false));
41    }
42
43    /// Start the timer in single pulse mode.
44    pub fn single_mode_start(&self) {
45        T::regs().cr().modify(|w| w.set_sngstrt(true));
46    }
47
48    /// Start the timer in continuous mode.
49    pub fn continuous_mode_start(&self) {
50        T::regs().cr().modify(|w| w.set_cntstrt(true));
51    }
52
53    /// Set the frequency of how many times per second the timer counts up to the max value or down to 0.
54    pub fn set_frequency(&self, frequency: Hertz) {
55        let f = frequency.0;
56        assert!(f > 0);
57
58        let pclk_f = T::frequency().0;
59
60        let pclk_ticks_per_timer_period = pclk_f / f;
61
62        let psc = Prescaler::from_ticks(pclk_ticks_per_timer_period);
63        let arr = psc.scale_down(pclk_ticks_per_timer_period);
64
65        T::regs().cfgr().modify(|r| r.set_presc((&psc).into()));
66        T::regs().arr().modify(|r| r.set_arr(arr.into()));
67    }
68
69    /// Get the timer frequency.
70    pub fn get_frequency(&self) -> Hertz {
71        let pclk_f = T::frequency();
72        let arr = T::regs().arr().read().arr();
73        let psc = Prescaler::from(T::regs().cfgr().read().presc());
74
75        pclk_f / psc.scale_up(arr)
76    }
77
78    /// Get the clock frequency of the timer (before prescaler is applied).
79    pub fn get_clock_frequency(&self) -> Hertz {
80        T::frequency()
81    }
82
83    /// Get max compare value. This depends on the timer frequency and the clock frequency from RCC.
84    pub fn get_max_compare_value(&self) -> u16 {
85        T::regs().arr().read().arr()
86    }
87}
88
89#[cfg(any(lptim_v2a, lptim_v2b))]
90impl<'d, T: Instance> Timer<'d, T> {
91    /// Enable/disable a channel.
92    pub fn enable_channel(&self, channel: Channel, enable: bool) {
93        T::regs().ccmr(0).modify(|w| {
94            w.set_cce(channel.index(), enable);
95        });
96    }
97
98    /// Get enable/disable state of a channel
99    pub fn get_channel_enable_state(&self, channel: Channel) -> bool {
100        T::regs().ccmr(0).read().cce(channel.index())
101    }
102
103    /// Set compare value for a channel.
104    pub fn set_compare_value(&self, channel: Channel, value: u16) {
105        T::regs().ccr(channel.index()).modify(|w| w.set_ccr(value));
106    }
107
108    /// Get compare value for a channel.
109    pub fn get_compare_value(&self, channel: Channel) -> u16 {
110        T::regs().ccr(channel.index()).read().ccr()
111    }
112
113    /// Set channel direction.
114    #[cfg(any(lptim_v2a, lptim_v2b))]
115    pub fn set_channel_direction(&self, channel: Channel, direction: ChannelDirection) {
116        T::regs()
117            .ccmr(0)
118            .modify(|w| w.set_ccsel(channel.index(), direction.into()));
119    }
120}
121
122#[cfg(not(any(lptim_v2a, lptim_v2b)))]
123impl<'d, T: Instance> Timer<'d, T> {
124    /// Set compare value for a channel.
125    pub fn set_compare_value(&self, value: u16) {
126        T::regs().cmp().modify(|w| w.set_cmp(value));
127    }
128
129    /// Get compare value for a channel.
130    pub fn get_compare_value(&self) -> u16 {
131        T::regs().cmp().read().cmp()
132    }
133}
embassy_stm32/lptim/timer/mod.rs

embassy_stm32/lptim/timer/
mod.rs
