Merge pull request #380 from bgamari/stm32g0-adc

Fix STM32G0 ADC

5 files changed, 251 insertions, 77 deletions

diff --git a/embassy-stm32/src/adc/g0.rs b/embassy-stm32/src/adc/g0.rs
deleted file mode 100644
index 8b1378917..000000000
--- a/embassy-stm32/src/adc/g0.rs
+++ /dev/null
@@ -1 +0,0 @@
-
diff --git a/embassy-stm32/src/adc/mod.rs b/embassy-stm32/src/adc/mod.rs
index 9955502a6..f292d0208 100644
--- a/embassy-stm32/src/adc/mod.rs
+++ b/embassy-stm32/src/adc/mod.rs
@@ -1,7 +1,7 @@
 #![macro_use]
 
 #[cfg_attr(adc_v3, path = "v3.rs")]
-#[cfg_attr(adc_g0, path = "g0.rs")]
+#[cfg_attr(adc_g0, path = "v3.rs")]
 mod _version;
 
 #[allow(unused)]
@@ -72,6 +72,9 @@ macro_rules! impl_pin {
 }
 
 crate::pac::peripheral_pins!(
+    ($inst:ident, adc, ADC, $pin:ident, IN0) => {
+        impl_pin!($inst, $pin, 0);
+    };
     ($inst:ident, adc, ADC, $pin:ident, IN1) => {
         impl_pin!($inst, $pin, 1);
     };
diff --git a/embassy-stm32/src/adc/v3.rs b/embassy-stm32/src/adc/v3.rs
index 2781fc4dc..ddf06deae 100644
--- a/embassy-stm32/src/adc/v3.rs
+++ b/embassy-stm32/src/adc/v3.rs
@@ -6,6 +6,17 @@ use embedded_hal::blocking::delay::DelayUs;
 
 pub const VDDA_CALIB_MV: u32 = 3000;
 
+/// Sadly we cannot use `RccPeripheral::enable` since devices are quite inconsistent ADC clock
+/// configuration.
+unsafe fn enable() {
+    #[cfg(rcc_h7)]
+    crate::pac::RCC.apb2enr().modify(|w| w.set_adcen(true));
+    #[cfg(rcc_g0)]
+    crate::pac::RCC.apbenr2().modify(|w| w.set_adcen(true));
+    #[cfg(rcc_l4)]
+    crate::pac::RCC.ahb2enr().modify(|w| w.set_adcen(true));
+}
+
 pub enum Resolution {
     TwelveBit,
     TenBit,
@@ -43,7 +54,11 @@ pub struct Vref;
 impl<T: Instance> AdcPin<T> for Vref {}
 impl<T: Instance> super::sealed::AdcPin<T> for Vref {
     fn channel(&self) -> u8 {
-        0
+        #[cfg(not(rcc_g0))]
+        let val = 0;
+        #[cfg(rcc_g0)]
+        let val = 13;
+        val
     }
 }
 
@@ -51,7 +66,11 @@ pub struct Temperature;
 impl<T: Instance> AdcPin<T> for Temperature {}
 impl<T: Instance> super::sealed::AdcPin<T> for Temperature {
     fn channel(&self) -> u8 {
-        17
+        #[cfg(not(rcc_g0))]
+        let val = 17;
+        #[cfg(rcc_g0)]
+        let val = 12;
+        val
     }
 }
 
@@ -59,61 +78,124 @@ pub struct Vbat;
 impl<T: Instance> AdcPin<T> for Vbat {}
 impl<T: Instance> super::sealed::AdcPin<T> for Vbat {
     fn channel(&self) -> u8 {
-        18
+        #[cfg(not(rcc_g0))]
+        let val = 18;
+        #[cfg(rcc_g0)]
+        let val = 14;
+        val
     }
 }
 
-/// ADC sample time
-///
-/// The default setting is 2.5 ADC clock cycles.
-#[derive(Clone, Copy, Debug, Eq, PartialEq, Ord, PartialOrd)]
-pub enum SampleTime {
-    /// 2.5 ADC clock cycles
-    Cycles2_5 = 0b000,
+#[cfg(not(adc_g0))]
+mod sample_time {
+    /// ADC sample time
+    ///
+    /// The default setting is 2.5 ADC clock cycles.
+    #[derive(Clone, Copy, Debug, Eq, PartialEq, Ord, PartialOrd)]
+    pub enum SampleTime {
+        /// 2.5 ADC clock cycles
+        Cycles2_5 = 0b000,
 
-    /// 6.5 ADC clock cycles
-    Cycles6_5 = 0b001,
+        /// 6.5 ADC clock cycles
+        Cycles6_5 = 0b001,
 
-    /// 12.5 ADC clock cycles
-    Cycles12_5 = 0b010,
+        /// 12.5 ADC clock cycles
+        Cycles12_5 = 0b010,
 
-    /// 24.5 ADC clock cycles
-    Cycles24_5 = 0b011,
+        /// 24.5 ADC clock cycles
+        Cycles24_5 = 0b011,
 
-    /// 47.5 ADC clock cycles
-    Cycles47_5 = 0b100,
+        /// 47.5 ADC clock cycles
+        Cycles47_5 = 0b100,
 
-    /// 92.5 ADC clock cycles
-    Cycles92_5 = 0b101,
+        /// 92.5 ADC clock cycles
+        Cycles92_5 = 0b101,
 
-    /// 247.5 ADC clock cycles
-    Cycles247_5 = 0b110,
+        /// 247.5 ADC clock cycles
+        Cycles247_5 = 0b110,
 
-    /// 640.5 ADC clock cycles
-    Cycles640_5 = 0b111,
-}
+        /// 640.5 ADC clock cycles
+        Cycles640_5 = 0b111,
+    }
 
-impl SampleTime {
-    fn sample_time(&self) -> crate::pac::adc::vals::SampleTime {
-        match self {
-            SampleTime::Cycles2_5 => crate::pac::adc::vals::SampleTime::CYCLES2_5,
-            SampleTime::Cycles6_5 => crate::pac::adc::vals::SampleTime::CYCLES6_5,
-            SampleTime::Cycles12_5 => crate::pac::adc::vals::SampleTime::CYCLES12_5,
-            SampleTime::Cycles24_5 => crate::pac::adc::vals::SampleTime::CYCLES24_5,
-            SampleTime::Cycles47_5 => crate::pac::adc::vals::SampleTime::CYCLES47_5,
-            SampleTime::Cycles92_5 => crate::pac::adc::vals::SampleTime::CYCLES92_5,
-            SampleTime::Cycles247_5 => crate::pac::adc::vals::SampleTime::CYCLES247_5,
-            SampleTime::Cycles640_5 => crate::pac::adc::vals::SampleTime::CYCLES640_5,
+    impl SampleTime {
+        pub(crate) fn sample_time(&self) -> crate::pac::adc::vals::SampleTime {
+            match self {
+                SampleTime::Cycles2_5 => crate::pac::adc::vals::SampleTime::CYCLES2_5,
+                SampleTime::Cycles6_5 => crate::pac::adc::vals::SampleTime::CYCLES6_5,
+                SampleTime::Cycles12_5 => crate::pac::adc::vals::SampleTime::CYCLES12_5,
+                SampleTime::Cycles24_5 => crate::pac::adc::vals::SampleTime::CYCLES24_5,
+                SampleTime::Cycles47_5 => crate::pac::adc::vals::SampleTime::CYCLES47_5,
+                SampleTime::Cycles92_5 => crate::pac::adc::vals::SampleTime::CYCLES92_5,
+                SampleTime::Cycles247_5 => crate::pac::adc::vals::SampleTime::CYCLES247_5,
+                SampleTime::Cycles640_5 => crate::pac::adc::vals::SampleTime::CYCLES640_5,
+            }
+        }
+    }
+
+    impl Default for SampleTime {
+        fn default() -> Self {
+            Self::Cycles2_5
         }
     }
 }
 
-impl Default for SampleTime {
-    fn default() -> Self {
-        Self::Cycles2_5
+#[cfg(adc_g0)]
+mod sample_time {
+    /// ADC sample time
+    ///
+    /// The default setting is 1.5 ADC clock cycles.
+    #[derive(Clone, Copy, Debug, Eq, PartialEq, Ord, PartialOrd)]
+    pub enum SampleTime {
+        /// 1.5 ADC clock cycles
+        Cycles1_5 = 0b000,
+
+        /// 3.5 ADC clock cycles
+        Cycles3_5 = 0b001,
+
+        /// 7.5 ADC clock cycles
+        Cycles7_5 = 0b010,
+
+        /// 12.5 ADC clock cycles
+        Cycles12_5 = 0b011,
+
+        /// 19.5 ADC clock cycles
+        Cycles19_5 = 0b100,
+
+        /// 39.5 ADC clock cycles
+        Cycles39_5 = 0b101,
+
+        /// 79.5 ADC clock cycles
+        Cycles79_5 = 0b110,
+
+        /// 160.5 ADC clock cycles
+        Cycles160_5 = 0b111,
+    }
+
+    impl SampleTime {
+        pub(crate) fn sample_time(&self) -> crate::pac::adc::vals::SampleTime {
+            match self {
+                SampleTime::Cycles1_5 => crate::pac::adc::vals::SampleTime::CYCLES1_5,
+                SampleTime::Cycles3_5 => crate::pac::adc::vals::SampleTime::CYCLES3_5,
+                SampleTime::Cycles7_5 => crate::pac::adc::vals::SampleTime::CYCLES7_5,
+                SampleTime::Cycles12_5 => crate::pac::adc::vals::SampleTime::CYCLES12_5,
+                SampleTime::Cycles19_5 => crate::pac::adc::vals::SampleTime::CYCLES19_5,
+                SampleTime::Cycles39_5 => crate::pac::adc::vals::SampleTime::CYCLES39_5,
+                SampleTime::Cycles79_5 => crate::pac::adc::vals::SampleTime::CYCLES79_5,
+                SampleTime::Cycles160_5 => crate::pac::adc::vals::SampleTime::CYCLES160_5,
+            }
+        }
+    }
+
+    impl Default for SampleTime {
+        fn default() -> Self {
+            Self::Cycles1_5
+        }
     }
 }
 
+pub use sample_time::SampleTime;
+
 pub struct Adc<'d, T: Instance> {
     sample_time: SampleTime,
     calibrated_vdda: u32,
@@ -125,15 +207,26 @@ impl<'d, T: Instance> Adc<'d, T> {
     pub fn new(_peri: impl Unborrow<Target = T> + 'd, delay: &mut impl DelayUs<u32>) -> Self {
         unborrow!(_peri);
         unsafe {
+            enable();
             T::regs().cr().modify(|reg| {
+                #[cfg(not(adc_g0))]
                 reg.set_deeppwd(false);
                 reg.set_advregen(true);
             });
+
+            #[cfg(adc_g0)]
+            T::regs().cfgr1().modify(|reg| {
+                reg.set_chselrmod(true);
+            });
         }
 
         delay.delay_us(20);
 
         unsafe {
+            T::regs().cr().modify(|reg| {
+                reg.set_adcal(true);
+            });
+
             while T::regs().cr().read().adcal() {
                 // spin
             }
@@ -229,6 +322,27 @@ impl<'d, T: Instance> Adc<'d, T> {
     }
      */
 
+    /// 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(&mut self, pin: &mut impl AdcPin<T>) -> u16 {
         unsafe {
             // Make sure bits are off
@@ -249,48 +363,36 @@ impl<'d, T: Instance> Adc<'d, T> {
             }
 
             // Configure ADC
+            #[cfg(not(rcc_g0))]
             T::regs()
                 .cfgr()
                 .modify(|reg| reg.set_res(self.resolution.res()));
+            #[cfg(rcc_g0)]
+            T::regs()
+                .cfgr1()
+                .modify(|reg| reg.set_res(self.resolution.res()));
 
             // Configure channel
             Self::set_channel_sample_time(pin.channel(), self.sample_time);
 
             // Select channel
+            #[cfg(not(rcc_g0))]
             T::regs().sqr1().write(|reg| reg.set_sq(0, pin.channel()));
+            #[cfg(rcc_g0)]
+            T::regs()
+                .chselr()
+                .write(|reg| reg.set_chsel(pin.channel() as u32));
 
-            // Start conversion
-            T::regs().isr().modify(|reg| {
-                reg.set_eos(true);
-                reg.set_eoc(true);
-            });
-            T::regs().cr().modify(|reg| {
-                reg.set_adstart(true);
-            });
-
-            while !T::regs().isr().read().eos() {
-                // spin
-            }
-
-            // Read ADC value first time and discard it, as per errata sheet.
-            // The errata states that if we do conversions slower than 1 kHz, the
-            // first read ADC value can be corrupted, so we discard it and measure again.
-
-            let _ = T::regs().dr().read();
-
-            T::regs().isr().modify(|reg| {
-                reg.set_eos(true);
-                reg.set_eoc(true);
-            });
-            T::regs().cr().modify(|reg| {
-                reg.set_adstart(true);
-            });
-
-            while !T::regs().isr().read().eos() {
-                // spin
-            }
+            // Some models are affected by an erratum:
+            // If we perform conversions slower than 1 kHz, the first read ADC value can be
+            // corrupted, so we discard it and measure again.
+            //
+            // STM32L471xx: Section 2.7.3
+            // STM32G4: Section 2.7.3
+            #[cfg(any(rcc_l4, rcc_g4))]
+            let _ = self.convert();
 
-            let val = T::regs().dr().read().0 as u16;
+            let val = self.convert();
 
             T::regs().cr().modify(|reg| reg.set_addis(true));
 
@@ -298,6 +400,14 @@ impl<'d, T: Instance> Adc<'d, T> {
         }
     }
 
+    #[cfg(rcc_g0)]
+    unsafe fn set_channel_sample_time(_ch: u8, sample_time: SampleTime) {
+        T::regs()
+            .smpr()
+            .modify(|reg| reg.set_smp1(sample_time.sample_time()));
+    }
+
+    #[cfg(not(rcc_g0))]
     unsafe fn set_channel_sample_time(ch: u8, sample_time: SampleTime) {
         if ch <= 9 {
             T::regs()
diff --git a/embassy-stm32/src/dac/v2.rs b/embassy-stm32/src/dac/v2.rs
index f46145b8d..55a881d89 100644
--- a/embassy-stm32/src/dac/v2.rs
+++ b/embassy-stm32/src/dac/v2.rs
@@ -5,6 +5,17 @@ use core::marker::PhantomData;
 use embassy::util::Unborrow;
 use embassy_hal_common::unborrow;
 
+/// Sadly we cannot use `RccPeripheral::enable` since devices are quite inconsistent DAC clock
+/// configuration.
+unsafe fn enable() {
+    #[cfg(rcc_h7)]
+    crate::pac::RCC.apb1lenr().modify(|w| w.set_dac12en(true));
+    #[cfg(rcc_g0)]
+    crate::pac::RCC.apbenr1().modify(|w| w.set_dac1en(true));
+    #[cfg(rcc_l4)]
+    crate::pac::RCC.apb1enr1().modify(|w| w.set_dac1en(true));
+}
+
 #[derive(Debug)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum Error {
@@ -91,6 +102,10 @@ impl<'d, T: Instance> Dac<'d, T> {
     ) -> Self {
         unborrow!(ch1, ch2);
 
+        unsafe {
+            enable();
+        }
+
         let ch1 = ch1.degrade_optional();
         if ch1.is_some() {
             unsafe {
diff --git a/embassy-stm32/src/rcc/g0/mod.rs b/embassy-stm32/src/rcc/g0/mod.rs
index 863db709d..c0b5b14e3 100644
--- a/embassy-stm32/src/rcc/g0/mod.rs
+++ b/embassy-stm32/src/rcc/g0/mod.rs
@@ -18,10 +18,37 @@ pub const LSI_FREQ: u32 = 32_000;
 #[derive(Clone, Copy)]
 pub enum ClockSrc {
     HSE(Hertz),
-    HSI16,
+    HSI16(HSI16Prescaler),
     LSI,
 }
 
+#[derive(Clone, Copy)]
+pub enum HSI16Prescaler {
+    NotDivided,
+    Div2,
+    Div4,
+    Div8,
+    Div16,
+    Div32,
+    Div64,
+    Div128,
+}
+
+impl Into<u8> for HSI16Prescaler {
+    fn into(self) -> u8 {
+        match self {
+            HSI16Prescaler::NotDivided => 0x00,
+            HSI16Prescaler::Div2 => 0x01,
+            HSI16Prescaler::Div4 => 0x02,
+            HSI16Prescaler::Div8 => 0x03,
+            HSI16Prescaler::Div16 => 0x04,
+            HSI16Prescaler::Div32 => 0x05,
+            HSI16Prescaler::Div64 => 0x06,
+            HSI16Prescaler::Div128 => 0x07,
+        }
+    }
+}
+
 impl Into<u8> for APBPrescaler {
     fn into(self) -> u8 {
         match self {
@@ -55,15 +82,17 @@ pub struct Config {
     mux: ClockSrc,
     ahb_pre: AHBPrescaler,
     apb_pre: APBPrescaler,
+    low_power_run: bool,
 }
 
 impl Default for Config {
     #[inline]
     fn default() -> Config {
         Config {
-            mux: ClockSrc::HSI16,
+            mux: ClockSrc::HSI16(HSI16Prescaler::NotDivided),
             ahb_pre: AHBPrescaler::NotDivided,
             apb_pre: APBPrescaler::NotDivided,
+            low_power_run: false,
         }
     }
 }
@@ -86,6 +115,12 @@ impl Config {
         self.apb_pre = pre;
         self
     }
+
+    #[inline]
+    pub fn low_power_run(mut self, on: bool) -> Self {
+        self.low_power_run = on;
+        self
+    }
 }
 
 /// RCC peripheral
@@ -119,14 +154,18 @@ impl RccExt for RCC {
     fn freeze(self, cfgr: Config) -> Clocks {
         let rcc = pac::RCC;
         let (sys_clk, sw) = match cfgr.mux {
-            ClockSrc::HSI16 => {
+            ClockSrc::HSI16(div) => {
                 // Enable HSI16
+                let div: u8 = div.into();
                 unsafe {
-                    rcc.cr().write(|w| w.set_hsion(true));
+                    rcc.cr().write(|w| {
+                        w.set_hsidiv(div);
+                        w.set_hsion(true)
+                    });
                     while !rcc.cr().read().hsirdy() {}
                 }
 
-                (HSI_FREQ, 0x00)
+                (HSI_FREQ >> div, 0x00)
             }
             ClockSrc::HSE(freq) => {
                 // Enable HSE
@@ -174,6 +213,14 @@ impl RccExt for RCC {
             }
         };
 
+        let pwr = pac::PWR;
+        if cfgr.low_power_run {
+            assert!(sys_clk.hz() <= 2_000_000.hz());
+            unsafe {
+                pwr.cr1().modify(|w| w.set_lpr(true));
+            }
+        }
+
         Clocks {
             sys: sys_clk.hz(),
             ahb: ahb_freq.hz(),