Merge #699

699: Add ADC support for H7 r=Dirbaio a=matoushybl

Seems to work on H743, ADC1 works fine, but ADC3 has different ADC_COMMON block which stm32-data does't yet support, so measuring VREFINT or TEMP doesn't work. I'd like to discuss how adding support for the different ADC_COMMON could be done.

Co-authored-by: Matous Hybl <hyblmatous@gmail.com>

embassy-stm32/build.rs

@@ -145,7 +145,10 @@ fn main() {
     // Generate RccPeripheral impls
 
     for p in METADATA.peripherals {
-        if !singletons.contains(&p.name.to_string()) {
+        // generating RccPeripheral impl for H7 ADC3 would result in bad frequency
+        if !singletons.contains(&p.name.to_string())
+            || (p.name == "ADC3" && METADATA.line.starts_with("STM32H7"))
+        {
             continue;
         }
 
@@ -459,12 +462,24 @@ fn main() {
                 if regs.kind == "adc" {
                     let peri = format_ident!("{}", p.name);
                     let pin_name = format_ident!("{}", pin.pin);
-                    let ch: u8 = pin.signal.strip_prefix("IN").unwrap().parse().unwrap();
 
+                    // H7 has differential voltage measurements
+                    let ch: Option<u8> = if pin.signal.starts_with("INP") {
+                        Some(pin.signal.strip_prefix("INP").unwrap().parse().unwrap())
+                    } else if pin.signal.starts_with("INN") {
+                        // TODO handle in the future when embassy supports differential measurements
+                        None
+                    } else if pin.signal.starts_with("IN") {
+                        Some(pin.signal.strip_prefix("IN").unwrap().parse().unwrap())
+                    } else {
+                        None
+                    };
+                    if let Some(ch) = ch {
                         g.extend(quote! {
                             impl_adc_pin!( #peri, #pin_name, #ch);
                         })
                     }
+                }
 
                 // DAC is special
                 if regs.kind == "dac" {

embassy-stm32/src/adc/mod.rs

@@ -1,9 +1,11 @@
 #![macro_use]
 
+#[cfg_attr(adc_v4, path = "v4.rs")]
 #[cfg_attr(adc_v3, path = "v3.rs")]
 #[cfg_attr(adc_v2, path = "v2.rs")]
 #[cfg_attr(adc_g0, path = "v3.rs")]
 #[cfg_attr(adc_f1, path = "f1.rs")]
+#[cfg_attr(adc_v1, path = "v1.rs")]
 mod _version;
 
 #[allow(unused)]
@@ -14,11 +16,11 @@ use crate::peripherals;
 pub(crate) mod sealed {
     pub trait Instance {
         fn regs() -> &'static crate::pac::adc::Adc;
-        #[cfg(not(adc_f1))]
+        #[cfg(all(not(adc_f1), not(adc_v1)))]
         fn common_regs() -> &'static crate::pac::adccommon::AdcCommon;
     }
 
-    #[cfg(not(adc_f1))]
+    #[cfg(all(not(adc_f1), not(adc_v1)))]
     pub trait Common {
         fn regs() -> &'static crate::pac::adccommon::AdcCommon;
     }
@@ -32,17 +34,18 @@ pub(crate) mod sealed {
 pub trait Instance: sealed::Instance + 'static {}
 #[cfg(adc_f1)]
 pub trait Instance: sealed::Instance + crate::rcc::RccPeripheral + 'static {}
-#[cfg(not(adc_f1))]
+#[cfg(all(not(adc_f1), not(adc_v1)))]
 pub trait Common: sealed::Common + 'static {}
 pub trait AdcPin<T: Instance>: sealed::AdcPin<T> {}
 
+#[cfg(not(stm32h7))]
 foreach_peripheral!(
     (adc, $inst:ident) => {
         impl crate::adc::sealed::Instance for peripherals::$inst {
             fn regs() -> &'static crate::pac::adc::Adc {
                 &crate::pac::$inst
             }
-            #[cfg(not(adc_f1))]
+            #[cfg(all(not(adc_f1), not(adc_v1)))]
             fn common_regs() -> &'static crate::pac::adccommon::AdcCommon {
                 foreach_peripheral!{
                     (adccommon, $common_inst:ident) => {
@@ -56,7 +59,45 @@ foreach_peripheral!(
     };
 );
 
-#[cfg(not(adc_f1))]
+#[cfg(stm32h7)]
+foreach_peripheral!(
+    (adc, ADC3) => {
+        impl crate::adc::sealed::Instance for peripherals::ADC3 {
+            fn regs() -> &'static crate::pac::adc::Adc {
+                &crate::pac::ADC3
+            }
+            #[cfg(all(not(adc_f1), not(adc_v1)))]
+            fn common_regs() -> &'static crate::pac::adccommon::AdcCommon {
+                foreach_peripheral!{
+                    (adccommon, ADC3_COMMON) => {
+                        return &crate::pac::ADC3_COMMON
+                    };
+                }
+            }
+        }
+
+        impl crate::adc::Instance for peripherals::ADC3 {}
+    };
+    (adc, $inst:ident) => {
+        impl crate::adc::sealed::Instance for peripherals::$inst {
+            fn regs() -> &'static crate::pac::adc::Adc {
+                &crate::pac::$inst
+            }
+            #[cfg(all(not(adc_f1), not(adc_v1)))]
+            fn common_regs() -> &'static crate::pac::adccommon::AdcCommon {
+                foreach_peripheral!{
+                    (adccommon, ADC_COMMON) => {
+                        return &crate::pac::ADC_COMMON
+                    };
+                }
+            }
+        }
+
+        impl crate::adc::Instance for peripherals::$inst {}
+    };
+);
+
+#[cfg(all(not(adc_f1), not(adc_v1)))]
 foreach_peripheral!(
     (adccommon, $inst:ident) => {
         impl sealed::Common for peripherals::$inst {

embassy-stm32/src/adc/v1.rs

@@ -0,0 +1 @@
+

embassy-stm32/src/adc/v4.rs

@@ -0,0 +1,542 @@
+use core::marker::PhantomData;
+
+use crate::time::{Hertz, U32Ext};
+use atomic_polyfill::AtomicU8;
+use atomic_polyfill::Ordering;
+use embassy::util::Unborrow;
+use embedded_hal_02::blocking::delay::DelayUs;
+use pac::adc::vals::{Adcaldif, Boost, Difsel, Exten, Pcsel};
+use pac::adccommon::vals::Presc;
+
+use crate::pac;
+
+use super::{AdcPin, Instance};
+
+pub enum Resolution {
+    SixteenBit,
+    FourteenBit,
+    TwelveBit,
+    TenBit,
+    EightBit,
+}
+
+impl Default for Resolution {
+    fn default() -> Self {
+        Self::SixteenBit
+    }
+}
+
+impl Resolution {
+    fn res(&self) -> pac::adc::vals::Res {
+        match self {
+            Resolution::SixteenBit => pac::adc::vals::Res::SIXTEENBIT,
+            Resolution::FourteenBit => pac::adc::vals::Res::FOURTEENBITV,
+            Resolution::TwelveBit => pac::adc::vals::Res::TWELVEBITV,
+            Resolution::TenBit => pac::adc::vals::Res::TENBIT,
+            Resolution::EightBit => pac::adc::vals::Res::EIGHTBIT,
+        }
+    }
+
+    pub fn to_max_count(&self) -> u32 {
+        match self {
+            Resolution::SixteenBit => (1 << 16) - 1,
+            Resolution::FourteenBit => (1 << 14) - 1,
+            Resolution::TwelveBit => (1 << 12) - 1,
+            Resolution::TenBit => (1 << 10) - 1,
+            Resolution::EightBit => (1 << 8) - 1,
+        }
+    }
+}
+
+pub trait InternalChannel<T>: sealed::InternalChannel<T> {}
+
+mod sealed {
+    pub trait InternalChannel<T> {
+        fn channel(&self) -> u8;
+    }
+}
+
+// NOTE: Vref/Temperature/Vbat are only available on ADC3 on H7, this currently cannot be modeled with stm32-data, so these are available from the software on all ADCs
+pub struct Vref;
+impl<T: Instance> InternalChannel<T> for Vref {}
+impl<T: Instance> sealed::InternalChannel<T> for Vref {
+    fn channel(&self) -> u8 {
+        19
+    }
+}
+
+pub struct Temperature;
+impl<T: Instance> InternalChannel<T> for Temperature {}
+impl<T: Instance> sealed::InternalChannel<T> for Temperature {
+    fn channel(&self) -> u8 {
+        18
+    }
+}
+
+pub struct Vbat;
+impl<T: Instance> InternalChannel<T> for Vbat {}
+impl<T: Instance> sealed::InternalChannel<T> for Vbat {
+    fn channel(&self) -> u8 {
+        // TODO this should be 14 for H7a/b/35
+        17
+    }
+}
+
+static ADC12_ENABLE_COUNTER: AtomicU8 = AtomicU8::new(0);
+
+#[cfg(stm32h7)]
+foreach_peripheral!(
+    (adc, ADC1) => {
+        impl crate::rcc::sealed::RccPeripheral for crate::peripherals::ADC1 {
+            fn frequency() -> crate::time::Hertz {
+                critical_section::with(|_| unsafe {
+                    match crate::rcc::get_freqs().adc {
+                        Some(ck) => ck,
+                        None => panic!("Invalid ADC clock configuration, AdcClockSource was likely not properly configured.")
+                    }
+                })
+            }
+
+            fn enable() {
+                critical_section::with(|_| unsafe {
+                    crate::pac::RCC.ahb1enr().modify(|w| w.set_adc12en(true))
+                });
+                ADC12_ENABLE_COUNTER.fetch_add(1, Ordering::SeqCst);
+            }
+
+            fn disable() {
+                if ADC12_ENABLE_COUNTER.load(Ordering::SeqCst) == 1 {
+                    critical_section::with(|_| unsafe {
+                        crate::pac::RCC.ahb1enr().modify(|w| w.set_adc12en(false));
+                    })
+                }
+                ADC12_ENABLE_COUNTER.fetch_sub(1, Ordering::SeqCst);
+            }
+
+            fn reset() {
+                if ADC12_ENABLE_COUNTER.load(Ordering::SeqCst) == 1 {
+                    critical_section::with(|_| unsafe {
+                        crate::pac::RCC.ahb1rstr().modify(|w| w.set_adc12rst(true));
+                        crate::pac::RCC.ahb1rstr().modify(|w| w.set_adc12rst(false));
+                    });
+                }
+            }
+        }
+
+        impl crate::rcc::RccPeripheral for crate::peripherals::ADC1 {}
+    };
+    (adc, ADC2) => {
+        impl crate::rcc::sealed::RccPeripheral for crate::peripherals::ADC2 {
+            fn frequency() -> crate::time::Hertz {
+                critical_section::with(|_| unsafe {
+                    match crate::rcc::get_freqs().adc {
+                        Some(ck) => ck,
+                        None => panic!("Invalid ADC clock configuration, AdcClockSource was likely not properly configured.")
+                    }
+                })
+            }
+
+            fn enable() {
+                critical_section::with(|_| unsafe {
+                    crate::pac::RCC.ahb1enr().modify(|w| w.set_adc12en(true))
+                });
+                ADC12_ENABLE_COUNTER.fetch_add(1, Ordering::SeqCst);
+            }
+
+            fn disable() {
+                if ADC12_ENABLE_COUNTER.load(Ordering::SeqCst) == 1 {
+                    critical_section::with(|_| unsafe {
+                        crate::pac::RCC.ahb1enr().modify(|w| w.set_adc12en(false));
+                    })
+                }
+                ADC12_ENABLE_COUNTER.fetch_sub(1, Ordering::SeqCst);
+            }
+
+            fn reset() {
+                if ADC12_ENABLE_COUNTER.load(Ordering::SeqCst) == 1 {
+                    critical_section::with(|_| unsafe {
+                        crate::pac::RCC.ahb1rstr().modify(|w| w.set_adc12rst(true));
+                        crate::pac::RCC.ahb1rstr().modify(|w| w.set_adc12rst(false));
+                    });
+                }
+            }
+        }
+
+        impl crate::rcc::RccPeripheral for crate::peripherals::ADC2 {}
+    };
+    (adc, ADC3) => {
+        impl crate::rcc::sealed::RccPeripheral for crate::peripherals::ADC3 {
+            fn frequency() -> crate::time::Hertz {
+                critical_section::with(|_| unsafe {
+                    match crate::rcc::get_freqs().adc {
+                        Some(ck) => ck,
+                        None => panic!("Invalid ADC clock configuration, AdcClockSource was likely not properly configured.")
+                    }
+                })
+            }
+
+            fn enable() {
+                critical_section::with(|_| unsafe {
+                    crate::pac::RCC.ahb4enr().modify(|w| w.set_adc3en(true))
+                });
+            }
+
+            fn disable() {
+                    critical_section::with(|_| unsafe {
+                        crate::pac::RCC.ahb4enr().modify(|w| w.set_adc3en(false));
+                    })
+            }
+
+            fn reset() {
+                    critical_section::with(|_| unsafe {
+                        crate::pac::RCC.ahb4rstr().modify(|w| w.set_adc3rst(true));
+                        crate::pac::RCC.ahb4rstr().modify(|w| w.set_adc3rst(false));
+                    });
+            }
+        }
+
+        impl crate::rcc::RccPeripheral for crate::peripherals::ADC3 {}
+    };
+);
+
+/// ADC sample time
+///
+/// The default setting is 2.5 ADC clock cycles.
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Ord, PartialOrd)]
+pub enum SampleTime {
+    /// 1.5 ADC clock cycles
+    Cycles1_5,
+
+    /// 2.5 ADC clock cycles
+    Cycles2_5,
+
+    /// 8.5 ADC clock cycles
+    Cycles8_5,
+
+    /// 16.5 ADC clock cycles
+    Cycles16_5,
+
+    /// 32.5 ADC clock cycles
+    Cycles32_5,
+
+    /// 64.5 ADC clock cycles
+    Cycles64_5,
+
+    /// 387.5 ADC clock cycles
+    Cycles387_5,
+
+    /// 810.5 ADC clock cycles
+    Cycles810_5,
+}
+
+impl SampleTime {
+    pub(crate) fn sample_time(&self) -> pac::adc::vals::Smp {
+        match self {
+            SampleTime::Cycles1_5 => pac::adc::vals::Smp::CYCLES1_5,
+            SampleTime::Cycles2_5 => pac::adc::vals::Smp::CYCLES2_5,
+            SampleTime::Cycles8_5 => pac::adc::vals::Smp::CYCLES8_5,
+            SampleTime::Cycles16_5 => pac::adc::vals::Smp::CYCLES16_5,
+            SampleTime::Cycles32_5 => pac::adc::vals::Smp::CYCLES32_5,
+            SampleTime::Cycles64_5 => pac::adc::vals::Smp::CYCLES64_5,
+            SampleTime::Cycles387_5 => pac::adc::vals::Smp::CYCLES387_5,
+            SampleTime::Cycles810_5 => pac::adc::vals::Smp::CYCLES810_5,
+        }
+    }
+}
+
+impl Default for SampleTime {
+    fn default() -> Self {
+        Self::Cycles1_5
+    }
+}
+
+// NOTE (unused): The prescaler enum closely copies the hardware capabilities,
+// but high prescaling doesn't make a lot of sense in the current implementation and is ommited.
+#[allow(unused)]
+enum Prescaler {
+    NotDivided,
+    DividedBy2,
+    DividedBy4,
+    DividedBy6,
+    DividedBy8,
+    DividedBy10,
+    DividedBy12,
+    DividedBy16,
+    DividedBy32,
+    DividedBy64,
+    DividedBy128,
+    DividedBy256,
+}
+
+impl Prescaler {
+    fn from_ker_ck(frequency: Hertz) -> Self {
+        let raw_prescaler = frequency.0 / 50_000_000;
+        match raw_prescaler {
+            0 => Self::NotDivided,
+            1 => Self::DividedBy2,
+            2..=3 => Self::DividedBy4,
+            4..=5 => Self::DividedBy6,
+            6..=7 => Self::DividedBy8,
+            8..=9 => Self::DividedBy10,
+            10..=11 => Self::DividedBy12,
+            _ => unimplemented!(),
+        }
+    }
+
+    fn divisor(&self) -> u32 {
+        match self {
+            Prescaler::NotDivided => 1,
+            Prescaler::DividedBy2 => 2,
+            Prescaler::DividedBy4 => 4,
+            Prescaler::DividedBy6 => 6,
+            Prescaler::DividedBy8 => 8,
+            Prescaler::DividedBy10 => 10,
+            Prescaler::DividedBy12 => 12,
+            Prescaler::DividedBy16 => 16,
+            Prescaler::DividedBy32 => 32,
+            Prescaler::DividedBy64 => 64,
+            Prescaler::DividedBy128 => 128,
+            Prescaler::DividedBy256 => 256,
+        }
+    }
+
+    fn presc(&self) -> Presc {
+        match self {
+            Prescaler::NotDivided => Presc::DIV1,
+            Prescaler::DividedBy2 => Presc::DIV2,
+            Prescaler::DividedBy4 => Presc::DIV4,
+            Prescaler::DividedBy6 => Presc::DIV6,
+            Prescaler::DividedBy8 => Presc::DIV8,
+            Prescaler::DividedBy10 => Presc::DIV10,
+            Prescaler::DividedBy12 => Presc::DIV12,
+            Prescaler::DividedBy16 => Presc::DIV16,
+            Prescaler::DividedBy32 => Presc::DIV32,
+            Prescaler::DividedBy64 => Presc::DIV64,
+            Prescaler::DividedBy128 => Presc::DIV128,
+            Prescaler::DividedBy256 => Presc::DIV256,
+        }
+    }
+}
+
+pub struct Adc<'d, T: Instance> {
+    sample_time: SampleTime,
+    resolution: Resolution,
+    phantom: PhantomData<&'d mut T>,
+}
+
+impl<'d, T: Instance + crate::rcc::RccPeripheral> Adc<'d, T> {
+    pub fn new(_peri: impl Unborrow<Target = T> + 'd, delay: &mut impl DelayUs<u16>) -> Self {
+        embassy_hal_common::unborrow!(_peri);
+        T::enable();
+        T::reset();
+
+        let prescaler = Prescaler::from_ker_ck(T::frequency());
+
+        unsafe {
+            T::common_regs()
+                .ccr()
+                .modify(|w| w.set_presc(prescaler.presc()));
+        }
+
+        let frequency = Hertz(T::frequency().0 / prescaler.divisor());
+        defmt::info!("ADC frequency set to {} Hz", frequency.0);
+
+        if frequency > 50.mhz().into() {
+            panic!("Maximal allowed frequency for the ADC is 50 MHz and it varies with different packages, refer to ST docs for more information.");
+        }
+        let boost = if frequency < 6_250.khz().into() {
+            Boost::LT6_25
+        } else if frequency < 12_500.khz().into() {
+            Boost::LT12_5
+        } else if frequency < 25.mhz().into() {
+            Boost::LT25
+        } else {
+            Boost::LT50
+        };
+        unsafe {
+            T::regs().cr().modify(|w| w.set_boost(boost));
+        }
+
+        let mut s = Self {
+            sample_time: Default::default(),
+            resolution: Resolution::default(),
+            phantom: PhantomData,
+        };
+        s.power_up(delay);
+        s.configure_differential_inputs();
+
+        s.calibrate();
+        delay.delay_us(1);
+
+        s.enable();
+        s.configure();
+
+        s
+    }
+
+    fn power_up(&mut self, delay: &mut impl DelayUs<u16>) {
+        unsafe {
+            T::regs().cr().modify(|reg| {
+                reg.set_deeppwd(false);
+                reg.set_advregen(true);
+            });
+        }
+
+        delay.delay_us(10);
+    }
+
+    fn configure_differential_inputs(&mut self) {
+        unsafe {
+            T::regs().difsel().modify(|w| {
+                for n in 0..20 {
+                    w.set_difsel(n, Difsel::SINGLEENDED);
+                }
+            })
+        };
+    }
+
+    fn calibrate(&mut self) {
+        unsafe {
+            T::regs().cr().modify(|w| {
+                w.set_adcaldif(Adcaldif::SINGLEENDED);
+                w.set_adcallin(true);
+            });
+
+            T::regs().cr().modify(|w| w.set_adcal(true));
+
+            while T::regs().cr().read().adcal() {}
+        }
+    }
+
+    fn enable(&mut self) {
+        unsafe {
+            T::regs().isr().write(|w| w.set_adrdy(true));
+            T::regs().cr().modify(|w| w.set_aden(true));
+            while !T::regs().isr().read().adrdy() {}
+            T::regs().isr().write(|w| w.set_adrdy(true));
+        }
+    }
+
+    fn configure(&mut self) {
+        // single conversion mode, software trigger
+        unsafe {
+            T::regs().cfgr().modify(|w| {
+                w.set_cont(false);
+                w.set_exten(Exten::DISABLED);
+            })
+        }
+    }
+
+    pub fn enable_vref(&self) -> Vref {
+        unsafe {
+            T::common_regs().ccr().modify(|reg| {
+                reg.set_vrefen(true);
+            });
+        }
+
+        Vref {}
+    }
+
+    pub fn enable_temperature(&self) -> Temperature {
+        unsafe {
+            T::common_regs().ccr().modify(|reg| {
+                reg.set_vsenseen(true);
+            });
+        }
+
+        Temperature {}
+    }
+
+    pub fn enable_vbat(&self) -> Vbat {
+        unsafe {
+            T::common_regs().ccr().modify(|reg| {
+                reg.set_vbaten(true);
+            });
+        }
+
+        Vbat {}
+    }
+
+    pub fn set_sample_time(&mut self, sample_time: SampleTime) {
+        self.sample_time = sample_time;
+    }
+
+    pub fn set_resolution(&mut self, resolution: Resolution) {
+        self.resolution = resolution;
+    }
+
+    /// Convert a measurement to millivolts
+    pub fn to_millivolts(&self, sample: u16) -> u16 {
+        ((u32::from(sample) * 3300) / self.resolution.to_max_count()) as u16
+    }
+
+    /// Perform a single conversion.
+    fn convert(&mut self) -> u16 {
+        unsafe {
+            T::regs().isr().modify(|reg| {
+                reg.set_eos(true);
+                reg.set_eoc(true);
+            });
+
+            // Start conversion
+            T::regs().cr().modify(|reg| {
+                reg.set_adstart(true);
+            });
+
+            while !T::regs().isr().read().eos() {
+                // spin
+            }
+
+            T::regs().dr().read().0 as u16
+        }
+    }
+
+    pub fn read<P>(&mut self, pin: &mut P) -> u16
+    where
+        P: AdcPin<T>,
+        P: crate::gpio::sealed::Pin,
+    {
+        unsafe {
+            pin.set_as_analog();
+
+            self.read_channel(pin.channel())
+        }
+    }
+
+    pub fn read_internal(&mut self, channel: &mut impl InternalChannel<T>) -> u16 {
+        unsafe { self.read_channel(channel.channel()) }
+    }
+
+    unsafe fn read_channel(&mut self, channel: u8) -> u16 {
+        // Configure ADC
+        T::regs()
+            .cfgr()
+            .modify(|reg| reg.set_res(self.resolution.res()));
+
+        // Configure channel
+        Self::set_channel_sample_time(channel, self.sample_time);
+
+        T::regs().cfgr2().modify(|w| w.set_lshift(0));
+        T::regs()
+            .pcsel()
+            .write(|w| w.set_pcsel(channel as _, Pcsel::PRESELECTED));
+        T::regs().sqr1().write(|reg| {
+            reg.set_sq(0, channel);
+            reg.set_l(0);
+        });
+
+        self.convert()
+    }
+
+    unsafe fn set_channel_sample_time(ch: u8, sample_time: SampleTime) {
+        if ch <= 9 {
+            T::regs()
+                .smpr(0)
+                .modify(|reg| reg.set_smp(ch as _, sample_time.sample_time()));
+        } else {
+            T::regs()
+                .smpr(1)
+                .modify(|reg| reg.set_smp((ch - 10) as _, sample_time.sample_time()));
+        }
+    }
+}

embassy-stm32/src/rcc/h7.rs

@@ -7,7 +7,7 @@ use stm32_metapac::rcc::vals::{Mco1, Mco2};
 use crate::gpio::sealed::AFType;
 use crate::gpio::Speed;
 use crate::pac::rcc::vals::Timpre;
-use crate::pac::rcc::vals::{Ckpersel, Dppre, Hpre, Hsidiv, Pllsrc, Sw};
+use crate::pac::rcc::vals::{Adcsel, Ckpersel, Dppre, Hpre, Hsidiv, Pllsrc, Sw};
 use crate::pac::{PWR, RCC, SYSCFG};
 use crate::peripherals;
 use crate::rcc::{set_freqs, Clocks};
@@ -36,6 +36,29 @@ pub enum VoltageScale {
     Scale3,
 }
 
+#[derive(Clone, Copy)]
+pub enum AdcClockSource {
+    Pll2PCk,
+    Pll3RCk,
+    PerCk,
+}
+
+impl AdcClockSource {
+    pub fn adcsel(&self) -> Adcsel {
+        match self {
+            AdcClockSource::Pll2PCk => Adcsel::PLL2_P,
+            AdcClockSource::Pll3RCk => Adcsel::PLL3_R,
+            AdcClockSource::PerCk => Adcsel::PER,
+        }
+    }
+}
+
+impl Default for AdcClockSource {
+    fn default() -> Self {
+        Self::Pll2PCk
+    }
+}
+
 /// Core clock frequencies
 #[derive(Clone, Copy)]
 pub struct CoreClocks {
@@ -65,6 +88,7 @@ pub struct CoreClocks {
     pub pll3_r_ck: Option<Hertz>,
     pub timx_ker_ck: Option<Hertz>,
     pub timy_ker_ck: Option<Hertz>,
+    pub adc_ker_ck: Option<Hertz>,
     pub sys_ck: Hertz,
     pub c_ck: Hertz,
 }
@@ -85,6 +109,7 @@ pub struct Config {
     pub pll1: PllConfig,
     pub pll2: PllConfig,
     pub pll3: PllConfig,
+    pub adc_clock_source: AdcClockSource,
 }
 
 /// Setup traceclk
@@ -614,6 +639,16 @@ pub(crate) unsafe fn init(mut config: Config) {
     // Peripheral Clock (per_ck)
     RCC.d1ccipr().modify(|w| w.set_ckpersel(ckpersel));
 
+    // ADC clock MUX
+    RCC.d3ccipr()
+        .modify(|w| w.set_adcsel(config.adc_clock_source.adcsel()));
+
+    let adc_ker_ck = match config.adc_clock_source {
+        AdcClockSource::Pll2PCk => pll2_p_ck.map(Hertz),
+        AdcClockSource::Pll3RCk => pll3_r_ck.map(Hertz),
+        AdcClockSource::PerCk => Some(per_ck),
+    };
+
     // Set timer clocks prescaler setting
     RCC.cfgr().modify(|w| w.set_timpre(timpre));
 
@@ -668,6 +703,7 @@ pub(crate) unsafe fn init(mut config: Config) {
         pll3_r_ck: pll3_r_ck.map(Hertz),
         timx_ker_ck: rcc_timerx_ker_ck.map(Hertz),
         timy_ker_ck: rcc_timery_ker_ck.map(Hertz),
+        adc_ker_ck,
         sys_ck,
         c_ck: Hertz(sys_d1cpre_ck),
     };
@@ -683,6 +719,7 @@ pub(crate) unsafe fn init(mut config: Config) {
         apb4: core_clocks.pclk4,
         apb1_tim: core_clocks.timx_ker_ck.unwrap_or(core_clocks.pclk1),
         apb2_tim: core_clocks.timy_ker_ck.unwrap_or(core_clocks.pclk2),
+        adc: core_clocks.adc_ker_ck,
     });
 }
 

embassy-stm32/src/rcc/mod.rs

@@ -58,6 +58,9 @@ pub struct Clocks {
 
     #[cfg(rcc_f1)]
     pub adc: Hertz,
+
+    #[cfg(any(rcc_h7, rcc_h7ab))]
+    pub adc: Option<Hertz>,
 }
 
 /// Frozen clock frequencies

examples/stm32h7/Cargo.toml

@@ -8,7 +8,7 @@ resolver = "2"
 [features]
 
 [dependencies]
-embassy = { version = "0.1.0", path = "../../embassy", features = ["defmt", "defmt-timestamp-uptime"] }
+embassy = { version = "0.1.0", path = "../../embassy", features = ["defmt", "defmt-timestamp-uptime", "unstable-traits"] }
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "stm32h743bi", "net", "time-driver-any", "exti", "unstable-pac", "unstable-traits"] }
 embassy-net = { path = "../../embassy-net", default-features = false, features = ["defmt", "tcp", "medium-ethernet", "pool-16"] }
 

examples/stm32h7/src/bin/adc.rs

@@ -0,0 +1,42 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use embassy::executor::Spawner;
+use embassy::time::{Delay, Duration, Timer};
+use embassy_stm32::adc::{Adc, SampleTime};
+use embassy_stm32::rcc::AdcClockSource;
+use embassy_stm32::time::U32Ext;
+use embassy_stm32::{Config, Peripherals};
+
+use defmt::*;
+use defmt_rtt as _; // global logger
+use panic_probe as _;
+
+pub fn config() -> Config {
+    let mut config = Config::default();
+    config.rcc.sys_ck = Some(400.mhz().into());
+    config.rcc.hclk = Some(200.mhz().into());
+    config.rcc.per_ck = Some(64.mhz().into());
+    config.rcc.adc_clock_source = AdcClockSource::PerCk;
+    config
+}
+
+#[embassy::main(config = "config()")]
+async fn main(_spawner: Spawner, mut p: Peripherals) {
+    info!("Hello World!");
+
+    let mut adc = Adc::new(p.ADC3, &mut Delay);
+
+    adc.set_sample_time(SampleTime::Cycles32_5);
+
+    let mut vref_channel = adc.enable_vref();
+
+    loop {
+        let vref = adc.read_internal(&mut vref_channel);
+        info!("vref: {}", vref);
+        let measured = adc.read(&mut p.PC0);
+        info!("measured: {}", measured);
+        Timer::after(Duration::from_millis(500)).await;
+    }
+}

stm32-data

@@ -1 +1 @@
-Subproject commit 5295cf1aa474aa4b70ba2bc19ab0ced0173cd792
+Subproject commit 8fb98d74620ab71fb9d0be2d800c427e0b77c46f