MCPWM MVP implementation

esp-hal-common/Cargo.toml

@@ -54,7 +54,7 @@ esp32   = { version = "0.16.0", features = ["critical-section"], optional = true
 esp32c2 = { version = "0.5.1",  features = ["critical-section"], optional = true }
 esp32c3 = { version = "0.8.1",  features = ["critical-section"], optional = true }
 esp32s2 = { version = "0.6.0",  features = ["critical-section"], optional = true }
-esp32s3 = { version = "0.9.0",  features = ["critical-section"], optional = true }
+esp32s3 = { version = "0.10.0",  features = ["critical-section"], optional = true }
 
 [features]
 esp32   = ["esp32/rt"  , "procmacros/xtensa", "xtensa-lx-rt/esp32",   "xtensa-lx/esp32",   "critical-section/restore-state-u32", "lock_api"]

esp-hal-common/src/clock.rs

@@ -113,6 +113,10 @@ pub struct Clocks {
     pub apb_clock: HertzU32,
     pub xtal_clock: HertzU32,
     pub i2c_clock: HertzU32,
+    #[cfg(esp32)]
+    pub pwm_clock: HertzU32,
+    #[cfg(esp32s3)]
+    pub crypto_pwm_clock: HertzU32,
     // TODO chip specific additional ones as needed
 }
 
@@ -129,6 +133,10 @@ impl Clocks {
             apb_clock: raw_clocks.apb_clock,
             xtal_clock: raw_clocks.xtal_clock,
             i2c_clock: raw_clocks.i2c_clock,
+            #[cfg(esp32)]
+            pwm_clock: raw_clocks.pwm_clock,
+            #[cfg(esp32s3)]
+            crypto_pwm_clock: raw_clocks.crypto_pwm_clock,
         }
     }
 }
@@ -139,6 +147,10 @@ pub struct RawClocks {
     pub apb_clock: HertzU32,
     pub xtal_clock: HertzU32,
     pub i2c_clock: HertzU32,
+    #[cfg(esp32)]
+    pub pwm_clock: HertzU32,
+    #[cfg(esp32s3)]
+    pub crypto_pwm_clock: HertzU32,
     // TODO chip specific additional ones as needed
 }
 
@@ -172,6 +184,7 @@ impl ClockControl {
                 apb_clock: HertzU32::MHz(80),
                 xtal_clock: HertzU32::MHz(40),
                 i2c_clock: HertzU32::MHz(80),
+                pwm_clock: HertzU32::MHz(160),
             },
         }
     }
@@ -200,6 +213,10 @@ impl ClockControl {
                 apb_clock: HertzU32::MHz(80),
                 xtal_clock: HertzU32::MHz(40),
                 i2c_clock: HertzU32::MHz(40),
+                // The docs are unclear here. pwm_clock seems to be tied to clocks.apb_clock
+                // while simultaneously being fixed at 160 MHz.
+                // Testing showed 160 MHz to be correct for current clock configurations.
+                pwm_clock: HertzU32::MHz(160),
             },
         }
     }
@@ -344,6 +361,7 @@ impl ClockControl {
                 apb_clock: HertzU32::MHz(80),
                 xtal_clock: HertzU32::MHz(40),
                 i2c_clock: HertzU32::MHz(40),
+                crypto_pwm_clock: HertzU32::MHz(160),
             },
         }
     }
@@ -360,6 +378,7 @@ impl ClockControl {
                 apb_clock: HertzU32::MHz(80),
                 xtal_clock: HertzU32::MHz(40),
                 i2c_clock: HertzU32::MHz(40),
+                crypto_pwm_clock: HertzU32::MHz(160),
             },
         }
     }

esp-hal-common/src/lib.rs

@@ -62,6 +62,8 @@ pub mod i2c;
 pub mod i2s;
 
 pub mod ledc;
+#[cfg(any(esp32, esp32s3))]
+pub mod mcpwm;
 #[cfg(usb_otg)]
 pub mod otg_fs;
 pub mod prelude;

esp-hal-common/src/mcpwm/mod.rs

@@ -0,0 +1,288 @@
+//! MCPWM (Motor Control Pulse Width Modulator) peripheral
+//!
+//! # Peripheral capabilities:
+//! * PWM Timers 0, 1 and 2
+//!     * Every PWM timer has a dedicated 8-bit clock prescaler.
+//!     * The 16-bit counter in the PWM timer can work in count-up mode,
+//!       count-down mode or count-up-down mode.
+//!     * A hardware sync or software sync can trigger a reload on the PWM timer
+//!       with a phase register (Not yet implemented)
+//! * PWM Operators 0, 1 and 2
+//!     * Every PWM operator has two PWM outputs: PWMxA and PWMxB. They can work
+//!       independently, in symmetric and asymmetric configuration.
+//!     * Software, asynchronously override control of PWM signals.
+//!     * Configurable dead-time on rising and falling edges; each set up
+//!       independently. (Not yet implemented)
+//!     * All events can trigger CPU interrupts. (Not yet implemented)
+//!     * Modulating of PWM output by high-frequency carrier signals, useful
+//!       when gate drivers are insulated with a transformer. (Not yet
+//!       implemented)
+//!     * Period, time stamps and important control registers have shadow
+//!       registers with flexible updating methods.
+//! * Fault Detection Module (Not yet implemented)
+//! * Capture Module (Not yet implemented)
+//!
+//! # Example
+//! Uses timer0 and operator0 of the MCPWM0 peripheral to output a 50% duty
+//! signal at 20 kHz. The signal will be output to the pin assigned to `pin`.
+//!
+//! ```
+//! # use esp_hal_common::{mcpwm, prelude::*};
+//! use mcpwm::{operator::PwmPinConfig, timer::PwmWorkingMode, PeripheralClockConfig, MCPWM};
+//!
+//! // initialize peripheral
+//! let clock_cfg = PeripheralClockConfig::with_frequency(&clocks, 40u32.MHz()).unwrap();
+//! let mut mcpwm = MCPWM::new(
+//!     peripherals.PWM0,
+//!     clock_cfg,
+//!     &mut system.peripheral_clock_control,
+//! );
+//!
+//! // connect operator0 to timer0
+//! mcpwm.operator0.set_timer(&mcpwm.timer0);
+//! // connect operator0 to pin
+//! let mut pwm_pin = mcpwm
+//!     .operator0
+//!     .with_pin_a(pin, PwmPinConfig::UP_ACTIVE_HIGH);
+//!
+//! // start timer with timestamp values in the range of 0..=99 and a frequency of 20 kHz
+//! let timer_clock_cfg = clock_cfg
+//!     .timer_clock_with_frequency(99, PwmWorkingMode::Increase, 20u32.kHz())
+//!     .unwrap();
+//! mcpwm.timer0.start(timer_clock_cfg);
+//!
+//! // pin will be high 50% of the time
+//! pwm_pin.set_timestamp(50);
+//! ```
+
+#![deny(missing_docs)]
+
+use core::{marker::PhantomData, ops::Deref};
+
+use fugit::HertzU32;
+use operator::Operator;
+use timer::Timer;
+
+use crate::{
+    clock::Clocks,
+    system::{Peripheral, PeripheralClockControl},
+    types::OutputSignal,
+};
+
+/// MCPWM operators
+pub mod operator;
+/// MCPWM timers
+pub mod timer;
+
+/// The MCPWM peripheral
+#[non_exhaustive]
+pub struct MCPWM<PWM> {
+    /// Timer0
+    pub timer0: Timer<0, PWM>,
+    /// Timer1
+    pub timer1: Timer<1, PWM>,
+    /// Timer2
+    pub timer2: Timer<2, PWM>,
+    /// Operator0
+    pub operator0: Operator<0, PWM>,
+    /// Operator1
+    pub operator1: Operator<1, PWM>,
+    /// Operator2
+    pub operator2: Operator<2, PWM>,
+}
+
+impl<PWM: PwmPeripheral> MCPWM<PWM> {
+    /// `pwm_clk = clocks.crypto_pwm_clock / (prescaler + 1)`
+    // clocks.crypto_pwm_clock normally is 160 MHz
+    pub fn new(
+        peripheral: PWM,
+        peripheral_clock: PeripheralClockConfig,
+        system: &mut PeripheralClockControl,
+    ) -> Self {
+        let _ = peripheral;
+
+        PWM::enable(system);
+
+        // set prescaler
+        peripheral
+            .clk_cfg
+            .write(|w| w.clk_prescale().variant(peripheral_clock.prescaler));
+        // enable clock
+        peripheral.clk.write(|w| w.en().set_bit());
+
+        MCPWM {
+            timer0: Timer::new(),
+            timer1: Timer::new(),
+            timer2: Timer::new(),
+            operator0: Operator::new(),
+            operator1: Operator::new(),
+            operator2: Operator::new(),
+        }
+    }
+}
+
+/// Clock configuration of the MCPWM peripheral
+#[derive(Copy, Clone)]
+pub struct PeripheralClockConfig<'a> {
+    frequency: HertzU32,
+    prescaler: u8,
+    phantom: PhantomData<&'a Clocks>,
+}
+
+impl<'a> PeripheralClockConfig<'a> {
+    /// Get a clock configuration with the given prescaler.
+    ///
+    /// With standard system clock configurations the input clock to the MCPWM
+    /// peripheral is `160 MHz`.
+    ///
+    /// The peripheral clock frequency is calculated as:
+    /// `peripheral_clock = input_clock / (prescaler + 1)`
+    pub fn with_prescaler(clocks: &'a Clocks, prescaler: u8) -> Self {
+        #[cfg(esp32)]
+        let source_clock = clocks.pwm_clock;
+        #[cfg(esp32s3)]
+        let source_clock = clocks.crypto_pwm_clock;
+
+        PeripheralClockConfig {
+            frequency: source_clock / (prescaler as u32 + 1),
+            prescaler,
+            phantom: PhantomData,
+        }
+    }
+
+    /// Get a clock configuration with the given frequency.
+    ///
+    /// ### Note:
+    /// This will try to select an appropriate prescaler for the
+    /// [`PeripheralClockConfig::with_prescaler`] method.
+    /// If the calculated prescaler is not in the range `0..u8::MAX`
+    /// [`FrequencyError`] will be returned.
+    ///
+    /// With standard system clock configurations the input clock to the MCPWM
+    /// peripheral is `160 MHz`.
+    ///
+    /// Only divisors of the input clock (`160 Mhz / 1`, `160 Mhz / 2`, ...,
+    /// `160 Mhz / 256`) are representable exactly. Other target frequencies
+    /// will be rounded up to the next divisor.
+    pub fn with_frequency(
+        clocks: &'a Clocks,
+        target_freq: HertzU32,
+    ) -> Result<Self, FrequencyError> {
+        #[cfg(esp32)]
+        let source_clock = clocks.pwm_clock;
+        #[cfg(esp32s3)]
+        let source_clock = clocks.crypto_pwm_clock;
+
+        if target_freq.raw() == 0 || target_freq > source_clock {
+            return Err(FrequencyError);
+        }
+        let prescaler = source_clock / target_freq - 1;
+        if prescaler > u8::MAX as u32 {
+            return Err(FrequencyError);
+        }
+        Ok(Self::with_prescaler(clocks, prescaler as u8))
+    }
+
+    /// Get the peripheral clock frequency.
+    ///
+    /// ### Note:
+    /// The actual value is rounded down to the nearest `u32` value
+    pub fn frequency(&self) -> HertzU32 {
+        self.frequency
+    }
+
+    /// Get a timer clock configuration with the given prescaler.
+    ///
+    /// The resulting timer frequency depends of the chosen
+    /// [`timer::PwmWorkingMode`].
+    ///
+    /// #### `PwmWorkingMode::Increase` or `PwmWorkingMode::Decrease`
+    /// `timer_frequency = peripheral_clock / (prescaler + 1) / (period + 1)`
+    /// #### `PwmWorkingMode::UpDown`
+    /// `timer_frequency = peripheral_clock / (prescaler + 1) / (2 * period)`
+    pub fn timer_clock_with_prescaler(
+        &self,
+        period: u16,
+        mode: timer::PwmWorkingMode,
+        prescaler: u8,
+    ) -> timer::TimerClockConfig<'a> {
+        timer::TimerClockConfig::with_prescaler(self, period, mode, prescaler)
+    }
+
+    /// Get a timer clock configuration with the given frequency.
+    ///
+    /// ### Note:
+    /// This will try to select an appropriate prescaler for the timer.
+    /// If the calculated prescaler is not in the range `0..u8::MAX`
+    /// [`FrequencyError`] will be returned.
+    ///
+    /// See [`PeripheralClockConfig::timer_clock_with_prescaler`] for how the
+    /// frequency is calculated.
+    pub fn timer_clock_with_frequency(
+        &self,
+        period: u16,
+        mode: timer::PwmWorkingMode,
+        target_freq: HertzU32,
+    ) -> Result<timer::TimerClockConfig<'a>, FrequencyError> {
+        timer::TimerClockConfig::with_frequency(self, period, mode, target_freq)
+    }
+}
+
+/// Target frequency could not be set.
+/// Check how the frequency is calculated in the corresponding method docs.
+#[derive(Copy, Clone, Debug)]
+pub struct FrequencyError;
+
+/// A MCPWM peripheral
+pub unsafe trait PwmPeripheral: Deref<Target = crate::pac::pwm0::RegisterBlock> {
+    /// Enable peripheral
+    fn enable(system: &mut PeripheralClockControl);
+    /// Get a pointer to the peripheral RegisterBlock
+    fn block() -> *const crate::pac::pwm0::RegisterBlock;
+    /// Get operator GPIO mux output signal
+    fn output_signal<const OP: u8, const IS_A: bool>() -> OutputSignal;
+}
+
+unsafe impl PwmPeripheral for crate::pac::PWM0 {
+    fn enable(system: &mut PeripheralClockControl) {
+        system.enable(Peripheral::Mcpwm0)
+    }
+
+    fn block() -> *const crate::pac::pwm0::RegisterBlock {
+        Self::ptr()
+    }
+
+    fn output_signal<const OP: u8, const IS_A: bool>() -> OutputSignal {
+        match (OP, IS_A) {
+            (0, true) => OutputSignal::PWM0_0A,
+            (1, true) => OutputSignal::PWM0_1A,
+            (2, true) => OutputSignal::PWM0_1A,
+            (0, false) => OutputSignal::PWM0_0B,
+            (1, false) => OutputSignal::PWM0_1B,
+            (2, false) => OutputSignal::PWM0_1B,
+            _ => unreachable!(),
+        }
+    }
+}
+
+unsafe impl PwmPeripheral for crate::pac::PWM1 {
+    fn enable(system: &mut PeripheralClockControl) {
+        system.enable(Peripheral::Mcpwm1)
+    }
+
+    fn block() -> *const crate::pac::pwm0::RegisterBlock {
+        Self::ptr()
+    }
+
+    fn output_signal<const OP: u8, const IS_A: bool>() -> OutputSignal {
+        match (OP, IS_A) {
+            (0, true) => OutputSignal::PWM1_0A,
+            (1, true) => OutputSignal::PWM1_1A,
+            (2, true) => OutputSignal::PWM1_1A,
+            (0, false) => OutputSignal::PWM1_0B,
+            (1, false) => OutputSignal::PWM1_1B,
+            (2, false) => OutputSignal::PWM1_1B,
+            _ => unreachable!(),
+        }
+    }
+}