//! Low-level timer driver. //! //! This is an unopinionated, very low-level driver for all STM32 timers. It allows direct register //! manipulation with the `regs_*()` methods, and has utility functions that are thin wrappers //! over the registers. //! //! The available functionality depends on the timer type. use embassy_hal_internal::{into_ref, Peripheral, PeripheralRef}; use super::*; use crate::pac::timer::vals; use crate::time::Hertz; /// Input capture mode. #[derive(Clone, Copy)] pub enum InputCaptureMode { /// Rising edge only. Rising, /// Falling edge only. Falling, /// Both rising or falling edges. BothEdges, } /// Input TI selection. #[derive(Clone, Copy)] pub enum InputTISelection { /// Normal Normal, /// Alternate Alternate, /// TRC TRC, } impl From for stm32_metapac::timer::vals::CcmrInputCcs { fn from(tisel: InputTISelection) -> Self { match tisel { InputTISelection::Normal => stm32_metapac::timer::vals::CcmrInputCcs::TI4, InputTISelection::Alternate => stm32_metapac::timer::vals::CcmrInputCcs::TI3, InputTISelection::TRC => stm32_metapac::timer::vals::CcmrInputCcs::TRC, } } } /// Timer counting mode. #[repr(u8)] #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)] pub enum CountingMode { #[default] /// The timer counts up to the reload value and then resets back to 0. EdgeAlignedUp, /// The timer counts down to 0 and then resets back to the reload value. EdgeAlignedDown, /// The timer counts up to the reload value and then counts back to 0. /// /// The output compare interrupt flags of channels configured in output are /// set when the counter is counting down. CenterAlignedDownInterrupts, /// The timer counts up to the reload value and then counts back to 0. /// /// The output compare interrupt flags of channels configured in output are /// set when the counter is counting up. CenterAlignedUpInterrupts, /// The timer counts up to the reload value and then counts back to 0. /// /// The output compare interrupt flags of channels configured in output are /// set when the counter is counting both up or down. CenterAlignedBothInterrupts, } impl CountingMode { /// Return whether this mode is edge-aligned (up or down). pub fn is_edge_aligned(&self) -> bool { matches!(self, CountingMode::EdgeAlignedUp | CountingMode::EdgeAlignedDown) } /// Return whether this mode is center-aligned. pub fn is_center_aligned(&self) -> bool { matches!( self, CountingMode::CenterAlignedDownInterrupts | CountingMode::CenterAlignedUpInterrupts | CountingMode::CenterAlignedBothInterrupts ) } } impl From for (vals::Cms, vals::Dir) { fn from(value: CountingMode) -> Self { match value { CountingMode::EdgeAlignedUp => (vals::Cms::EDGEALIGNED, vals::Dir::UP), CountingMode::EdgeAlignedDown => (vals::Cms::EDGEALIGNED, vals::Dir::DOWN), CountingMode::CenterAlignedDownInterrupts => (vals::Cms::CENTERALIGNED1, vals::Dir::UP), CountingMode::CenterAlignedUpInterrupts => (vals::Cms::CENTERALIGNED2, vals::Dir::UP), CountingMode::CenterAlignedBothInterrupts => (vals::Cms::CENTERALIGNED3, vals::Dir::UP), } } } impl From<(vals::Cms, vals::Dir)> for CountingMode { fn from(value: (vals::Cms, vals::Dir)) -> Self { match value { (vals::Cms::EDGEALIGNED, vals::Dir::UP) => CountingMode::EdgeAlignedUp, (vals::Cms::EDGEALIGNED, vals::Dir::DOWN) => CountingMode::EdgeAlignedDown, (vals::Cms::CENTERALIGNED1, _) => CountingMode::CenterAlignedDownInterrupts, (vals::Cms::CENTERALIGNED2, _) => CountingMode::CenterAlignedUpInterrupts, (vals::Cms::CENTERALIGNED3, _) => CountingMode::CenterAlignedBothInterrupts, } } } /// Output compare mode. #[derive(Clone, Copy)] pub enum OutputCompareMode { /// The comparison between the output compare register TIMx_CCRx and /// the counter TIMx_CNT has no effect on the outputs. /// (this mode is used to generate a timing base). Frozen, /// Set channel to active level on match. OCxREF signal is forced high when the /// counter TIMx_CNT matches the capture/compare register x (TIMx_CCRx). ActiveOnMatch, /// Set channel to inactive level on match. OCxREF signal is forced low when the /// counter TIMx_CNT matches the capture/compare register x (TIMx_CCRx). InactiveOnMatch, /// Toggle - OCxREF toggles when TIMx_CNT=TIMx_CCRx. Toggle, /// Force inactive level - OCxREF is forced low. ForceInactive, /// Force active level - OCxREF is forced high. ForceActive, /// PWM mode 1 - In upcounting, channel is active as long as TIMx_CNTTIMx_CCRx else active (OCxREF=1). PwmMode1, /// PWM mode 2 - In upcounting, channel is inactive as long as /// TIMx_CNTTIMx_CCRx else inactive. PwmMode2, // TODO: there's more modes here depending on the chip family. } impl From for stm32_metapac::timer::vals::Ocm { fn from(mode: OutputCompareMode) -> Self { match mode { OutputCompareMode::Frozen => stm32_metapac::timer::vals::Ocm::FROZEN, OutputCompareMode::ActiveOnMatch => stm32_metapac::timer::vals::Ocm::ACTIVEONMATCH, OutputCompareMode::InactiveOnMatch => stm32_metapac::timer::vals::Ocm::INACTIVEONMATCH, OutputCompareMode::Toggle => stm32_metapac::timer::vals::Ocm::TOGGLE, OutputCompareMode::ForceInactive => stm32_metapac::timer::vals::Ocm::FORCEINACTIVE, OutputCompareMode::ForceActive => stm32_metapac::timer::vals::Ocm::FORCEACTIVE, OutputCompareMode::PwmMode1 => stm32_metapac::timer::vals::Ocm::PWMMODE1, OutputCompareMode::PwmMode2 => stm32_metapac::timer::vals::Ocm::PWMMODE2, } } } /// Timer output pin polarity. #[derive(Clone, Copy)] pub enum OutputPolarity { /// Active high (higher duty value makes the pin spend more time high). ActiveHigh, /// Active low (higher duty value makes the pin spend more time low). ActiveLow, } impl From for bool { fn from(mode: OutputPolarity) -> Self { match mode { OutputPolarity::ActiveHigh => false, OutputPolarity::ActiveLow => true, } } } /// Low-level timer driver. pub struct Timer<'d, T: CoreInstance> { tim: PeripheralRef<'d, T>, } impl<'d, T: CoreInstance> Drop for Timer<'d, T> { fn drop(&mut self) { T::disable() } } impl<'d, T: CoreInstance> Timer<'d, T> { /// Create a new timer driver. pub fn new(tim: impl Peripheral

+ 'd) -> Self { into_ref!(tim); T::enable_and_reset(); Self { tim } } /// Get access to the virutal core 16bit timer registers. /// /// Note: This works even if the timer is more capable, because registers /// for the less capable timers are a subset. This allows writing a driver /// for a given set of capabilities, and having it transparently work with /// more capable timers. pub fn regs_core(&self) -> crate::pac::timer::TimCore { unsafe { crate::pac::timer::TimCore::from_ptr(T::regs()) } } #[cfg(not(stm32l0))] fn regs_gp32_unchecked(&self) -> crate::pac::timer::TimGp32 { unsafe { crate::pac::timer::TimGp32::from_ptr(T::regs()) } } /// Start the timer. pub fn start(&self) { self.regs_core().cr1().modify(|r| r.set_cen(true)); } /// Stop the timer. pub fn stop(&self) { self.regs_core().cr1().modify(|r| r.set_cen(false)); } /// Reset the counter value to 0 pub fn reset(&self) { self.regs_core().cnt().write(|r| r.set_cnt(0)); } /// Set the frequency of how many times per second the timer counts up to the max value or down to 0. /// /// This means that in the default edge-aligned mode, /// the timer counter will wrap around at the same frequency as is being set. /// In center-aligned mode (which not all timers support), the wrap-around frequency is effectively halved /// because it needs to count up and down. pub fn set_frequency(&self, frequency: Hertz) { let f = frequency.0; assert!(f > 0); let timer_f = T::frequency().0; match T::BITS { TimerBits::Bits16 => { let pclk_ticks_per_timer_period = timer_f / f; let psc: u16 = unwrap!(((pclk_ticks_per_timer_period - 1) / (1 << 16)).try_into()); let divide_by = pclk_ticks_per_timer_period / (u32::from(psc) + 1); // the timer counts `0..=arr`, we want it to count `0..divide_by` let arr = unwrap!(u16::try_from(divide_by - 1)); let regs = self.regs_core(); regs.psc().write_value(psc); regs.arr().write(|r| r.set_arr(arr)); regs.cr1().modify(|r| r.set_urs(vals::Urs::COUNTERONLY)); regs.egr().write(|r| r.set_ug(true)); regs.cr1().modify(|r| r.set_urs(vals::Urs::ANYEVENT)); } #[cfg(not(stm32l0))] TimerBits::Bits32 => { let pclk_ticks_per_timer_period = (timer_f / f) as u64; let psc: u16 = unwrap!(((pclk_ticks_per_timer_period - 1) / (1 << 32)).try_into()); let divide_by = pclk_ticks_per_timer_period / (u64::from(psc) + 1); // the timer counts `0..=arr`, we want it to count `0..divide_by` let arr: u32 = unwrap!(u32::try_from(divide_by - 1)); let regs = self.regs_gp32_unchecked(); regs.psc().write_value(psc); regs.arr().write_value(arr); regs.cr1().modify(|r| r.set_urs(vals::Urs::COUNTERONLY)); regs.egr().write(|r| r.set_ug(true)); regs.cr1().modify(|r| r.set_urs(vals::Urs::ANYEVENT)); } } } /// Clear update interrupt. /// /// Returns whether the update interrupt flag was set. pub fn clear_update_interrupt(&self) -> bool { let regs = self.regs_core(); let sr = regs.sr().read(); if sr.uif() { regs.sr().modify(|r| { r.set_uif(false); }); true } else { false } } /// Enable/disable the update interrupt. pub fn enable_update_interrupt(&self, enable: bool) { self.regs_core().dier().modify(|r| r.set_uie(enable)); } /// Enable/disable autoreload preload. pub fn set_autoreload_preload(&self, enable: bool) { self.regs_core().cr1().modify(|r| r.set_arpe(enable)); } /// Get the timer frequency. pub fn get_frequency(&self) -> Hertz { let timer_f = T::frequency(); match T::BITS { TimerBits::Bits16 => { let regs = self.regs_core(); let arr = regs.arr().read().arr(); let psc = regs.psc().read(); timer_f / arr / (psc + 1) } #[cfg(not(stm32l0))] TimerBits::Bits32 => { let regs = self.regs_gp32_unchecked(); let arr = regs.arr().read(); let psc = regs.psc().read(); timer_f / arr / (psc + 1) } } } /// Get the clock frequency of the timer (before prescaler is applied). pub fn get_clock_frequency(&self) -> Hertz { T::frequency() } } impl<'d, T: BasicNoCr2Instance> Timer<'d, T> { /// Get access to the Baisc 16bit timer registers. /// /// Note: This works even if the timer is more capable, because registers /// for the less capable timers are a subset. This allows writing a driver /// for a given set of capabilities, and having it transparently work with /// more capable timers. pub fn regs_basic_no_cr2(&self) -> crate::pac::timer::TimBasicNoCr2 { unsafe { crate::pac::timer::TimBasicNoCr2::from_ptr(T::regs()) } } /// Enable/disable the update dma. pub fn enable_update_dma(&self, enable: bool) { self.regs_basic_no_cr2().dier().modify(|r| r.set_ude(enable)); } /// Get the update dma enable/disable state. pub fn get_update_dma_state(&self) -> bool { self.regs_basic_no_cr2().dier().read().ude() } } impl<'d, T: BasicInstance> Timer<'d, T> { /// Get access to the Baisc 16bit timer registers. /// /// Note: This works even if the timer is more capable, because registers /// for the less capable timers are a subset. This allows writing a driver /// for a given set of capabilities, and having it transparently work with /// more capable timers. pub fn regs_basic(&self) -> crate::pac::timer::TimBasic { unsafe { crate::pac::timer::TimBasic::from_ptr(T::regs()) } } } impl<'d, T: GeneralInstance1Channel> Timer<'d, T> { /// Get access to the general purpose 1 channel 16bit timer registers. /// /// Note: This works even if the timer is more capable, because registers /// for the less capable timers are a subset. This allows writing a driver /// for a given set of capabilities, and having it transparently work with /// more capable timers. pub fn regs_1ch(&self) -> crate::pac::timer::Tim1ch { unsafe { crate::pac::timer::Tim1ch::from_ptr(T::regs()) } } /// Set clock divider. pub fn set_clock_division(&self, ckd: vals::Ckd) { self.regs_1ch().cr1().modify(|r| r.set_ckd(ckd)); } /// Get max compare value. This depends on the timer frequency and the clock frequency from RCC. pub fn get_max_compare_value(&self) -> u32 { match T::BITS { TimerBits::Bits16 => self.regs_1ch().arr().read().arr() as u32, #[cfg(not(stm32l0))] TimerBits::Bits32 => self.regs_gp32_unchecked().arr().read(), } } } impl<'d, T: GeneralInstance2Channel> Timer<'d, T> { /// Get access to the general purpose 2 channel 16bit timer registers. /// /// Note: This works even if the timer is more capable, because registers /// for the less capable timers are a subset. This allows writing a driver /// for a given set of capabilities, and having it transparently work with /// more capable timers. pub fn regs_2ch(&self) -> crate::pac::timer::Tim2ch { unsafe { crate::pac::timer::Tim2ch::from_ptr(T::regs()) } } } impl<'d, T: GeneralInstance4Channel> Timer<'d, T> { /// Get access to the general purpose 16bit timer registers. /// /// Note: This works even if the timer is more capable, because registers /// for the less capable timers are a subset. This allows writing a driver /// for a given set of capabilities, and having it transparently work with /// more capable timers. pub fn regs_gp16(&self) -> crate::pac::timer::TimGp16 { unsafe { crate::pac::timer::TimGp16::from_ptr(T::regs()) } } /// Enable timer outputs. pub fn enable_outputs(&self) { self.tim.enable_outputs() } /// Set counting mode. pub fn set_counting_mode(&self, mode: CountingMode) { let (cms, dir) = mode.into(); let timer_enabled = self.regs_core().cr1().read().cen(); // Changing from edge aligned to center aligned (and vice versa) is not allowed while the timer is running. // Changing direction is discouraged while the timer is running. assert!(!timer_enabled); self.regs_gp16().cr1().modify(|r| r.set_dir(dir)); self.regs_gp16().cr1().modify(|r| r.set_cms(cms)) } /// Get counting mode. pub fn get_counting_mode(&self) -> CountingMode { let cr1 = self.regs_gp16().cr1().read(); (cr1.cms(), cr1.dir()).into() } /// Set input capture filter. pub fn set_input_capture_filter(&self, channel: Channel, icf: vals::FilterValue) { let raw_channel = channel.index(); self.regs_gp16() .ccmr_input(raw_channel / 2) .modify(|r| r.set_icf(raw_channel % 2, icf)); } /// Clear input interrupt. pub fn clear_input_interrupt(&self, channel: Channel) { self.regs_gp16().sr().modify(|r| r.set_ccif(channel.index(), false)); } /// Get input interrupt. pub fn get_input_interrupt(&self, channel: Channel) -> bool { self.regs_gp16().sr().read().ccif(channel.index()) } /// Enable input interrupt. pub fn enable_input_interrupt(&self, channel: Channel, enable: bool) { self.regs_gp16().dier().modify(|r| r.set_ccie(channel.index(), enable)); } /// Set input capture prescaler. pub fn set_input_capture_prescaler(&self, channel: Channel, factor: u8) { let raw_channel = channel.index(); self.regs_gp16() .ccmr_input(raw_channel / 2) .modify(|r| r.set_icpsc(raw_channel % 2, factor)); } /// Set input TI selection. pub fn set_input_ti_selection(&self, channel: Channel, tisel: InputTISelection) { let raw_channel = channel.index(); self.regs_gp16() .ccmr_input(raw_channel / 2) .modify(|r| r.set_ccs(raw_channel % 2, tisel.into())); } /// Set input capture mode. pub fn set_input_capture_mode(&self, channel: Channel, mode: InputCaptureMode) { self.regs_gp16().ccer().modify(|r| match mode { InputCaptureMode::Rising => { r.set_ccnp(channel.index(), false); r.set_ccp(channel.index(), false); } InputCaptureMode::Falling => { r.set_ccnp(channel.index(), false); r.set_ccp(channel.index(), true); } InputCaptureMode::BothEdges => { r.set_ccnp(channel.index(), true); r.set_ccp(channel.index(), true); } }); } /// Set output compare mode. pub fn set_output_compare_mode(&self, channel: Channel, mode: OutputCompareMode) { let raw_channel: usize = channel.index(); self.regs_gp16() .ccmr_output(raw_channel / 2) .modify(|w| w.set_ocm(raw_channel % 2, mode.into())); } /// Set output polarity. pub fn set_output_polarity(&self, channel: Channel, polarity: OutputPolarity) { self.regs_gp16() .ccer() .modify(|w| w.set_ccp(channel.index(), polarity.into())); } /// Enable/disable a channel. pub fn enable_channel(&self, channel: Channel, enable: bool) { self.regs_gp16().ccer().modify(|w| w.set_cce(channel.index(), enable)); } /// Get enable/disable state of a channel pub fn get_channel_enable_state(&self, channel: Channel) -> bool { self.regs_gp16().ccer().read().cce(channel.index()) } /// Set compare value for a channel. pub fn set_compare_value(&self, channel: Channel, value: u32) { match T::BITS { TimerBits::Bits16 => { let value = unwrap!(u16::try_from(value)); self.regs_gp16().ccr(channel.index()).modify(|w| w.set_ccr(value)); } #[cfg(not(stm32l0))] TimerBits::Bits32 => { self.regs_gp32_unchecked().ccr(channel.index()).write_value(value); } } } /// Get compare value for a channel. pub fn get_compare_value(&self, channel: Channel) -> u32 { match T::BITS { TimerBits::Bits16 => self.regs_gp16().ccr(channel.index()).read().ccr() as u32, #[cfg(not(stm32l0))] TimerBits::Bits32 => self.regs_gp32_unchecked().ccr(channel.index()).read(), } } /// Get capture value for a channel. pub fn get_capture_value(&self, channel: Channel) -> u32 { self.get_compare_value(channel) } /// Set output compare preload. pub fn set_output_compare_preload(&self, channel: Channel, preload: bool) { let channel_index = channel.index(); self.regs_gp16() .ccmr_output(channel_index / 2) .modify(|w| w.set_ocpe(channel_index % 2, preload)); } /// Get capture compare DMA selection pub fn get_cc_dma_selection(&self) -> vals::Ccds { self.regs_gp16().cr2().read().ccds() } /// Set capture compare DMA selection pub fn set_cc_dma_selection(&self, ccds: vals::Ccds) { self.regs_gp16().cr2().modify(|w| w.set_ccds(ccds)) } /// Get capture compare DMA enable state pub fn get_cc_dma_enable_state(&self, channel: Channel) -> bool { self.regs_gp16().dier().read().ccde(channel.index()) } /// Set capture compare DMA enable state pub fn set_cc_dma_enable_state(&self, channel: Channel, ccde: bool) { self.regs_gp16().dier().modify(|w| w.set_ccde(channel.index(), ccde)) } } #[cfg(not(stm32l0))] impl<'d, T: GeneralInstance32bit4Channel> Timer<'d, T> { /// Get access to the general purpose 32bit timer registers. /// /// Note: This works even if the timer is more capable, because registers /// for the less capable timers are a subset. This allows writing a driver /// for a given set of capabilities, and having it transparently work with /// more capable timers. pub fn regs_gp32(&self) -> crate::pac::timer::TimGp32 { unsafe { crate::pac::timer::TimGp32::from_ptr(T::regs()) } } } #[cfg(not(stm32l0))] impl<'d, T: AdvancedInstance1Channel> Timer<'d, T> { /// Get access to the general purpose 1 channel with one complementary 16bit timer registers. /// /// Note: This works even if the timer is more capable, because registers /// for the less capable timers are a subset. This allows writing a driver /// for a given set of capabilities, and having it transparently work with /// more capable timers. pub fn regs_1ch_cmp(&self) -> crate::pac::timer::Tim1chCmp { unsafe { crate::pac::timer::Tim1chCmp::from_ptr(T::regs()) } } /// Set clock divider for the dead time. pub fn set_dead_time_clock_division(&self, value: vals::Ckd) { self.regs_1ch_cmp().cr1().modify(|w| w.set_ckd(value)); } /// Set dead time, as a fraction of the max duty value. pub fn set_dead_time_value(&self, value: u8) { self.regs_1ch_cmp().bdtr().modify(|w| w.set_dtg(value)); } /// Set state of MOE-bit in BDTR register to en-/disable output pub fn set_moe(&self, enable: bool) { self.regs_1ch_cmp().bdtr().modify(|w| w.set_moe(enable)); } } #[cfg(not(stm32l0))] impl<'d, T: AdvancedInstance2Channel> Timer<'d, T> { /// Get access to the general purpose 2 channel with one complementary 16bit timer registers. /// /// Note: This works even if the timer is more capable, because registers /// for the less capable timers are a subset. This allows writing a driver /// for a given set of capabilities, and having it transparently work with /// more capable timers. pub fn regs_2ch_cmp(&self) -> crate::pac::timer::Tim2chCmp { unsafe { crate::pac::timer::Tim2chCmp::from_ptr(T::regs()) } } } #[cfg(not(stm32l0))] impl<'d, T: AdvancedInstance4Channel> Timer<'d, T> { /// Get access to the advanced timer registers. pub fn regs_advanced(&self) -> crate::pac::timer::TimAdv { unsafe { crate::pac::timer::TimAdv::from_ptr(T::regs()) } } /// Set complementary output polarity. pub fn set_complementary_output_polarity(&self, channel: Channel, polarity: OutputPolarity) { self.regs_advanced() .ccer() .modify(|w| w.set_ccnp(channel.index(), polarity.into())); } /// Enable/disable a complementary channel. pub fn enable_complementary_channel(&self, channel: Channel, enable: bool) { self.regs_advanced() .ccer() .modify(|w| w.set_ccne(channel.index(), enable)); } }