Initial support for PWM

- Update timer.rs with features from `stm32f4xx-hal`
- Remove chip feature for examples
- Use H7 HAL as a base for `pwm.rs`

Author: maximeborges

Cargo.toml

@@ -113,54 +113,58 @@ lto = true
 
 [[example]]
 name = "blinky_delay"
-required-features = ["stm32f746", "rt"]
+required-features = ["rt"] # stm32f746
 
 [[example]]
 name = "blinky"
-required-features = ["stm32f746", "rt"]
+required-features = ["device-selected", "rt"] # stm32f746
 
 [[example]]
 name = "flash"
-required-features = ["stm32f746", "rt"]
+required-features = ["device-selected", "rt"] # stm32f746
 
 [[example]]
 name = "fmc"
-required-features = ["stm32f746", "rt", "fmc"]
+required-features = ["device-selected", "rt", "fmc"] # stm32f746
 
 [[example]]
 name = "hello"
-required-features = ["stm32f746", "rt"]
+required-features = ["device-selected", "rt"] # stm32f746
+
+[[example]]
+name = "pwm"
+required-features = ["device-selected", "rt"] # stm32f767
 
 [[example]]
 name = "serial_delay"
-required-features = ["stm32f746", "rt"]
+required-features = ["device-selected", "rt"] # stm32f746
 
 [[example]]
 name = "serial_echo"
-required-features = ["stm32f746", "rt"]
+required-features = ["device-selected", "rt"] # stm32f746
 
 [[example]]
 name = "timer"
-required-features = ["stm32f746", "rt"]
+required-features = ["device-selected", "rt"] # stm32f746
 
 [[example]]
 name = "stm32f7disco-screen"
-required-features = ["stm32f746", "rt"]
+required-features = ["device-selected", "rt"] # stm32f746
 
 [[example]]
 name = "exti_button"
-required-features = ["stm32f767", "rt"]
+required-features = ["device-selected", "rt"] # stm32f746
 
 [[example]]
 name = "usb_serial"
-required-features = ["stm32f723", "rt", "synopsys-usb-otg"]
+required-features = ["device-selected", "rt", "synopsys-usb-otg"] # stm32f723
 
 [[example]]
 name = "rng"
 
 [[example]]
 name = "stm32f7disco-qspi-flash"
-required-features = ["stm32f746", "rt"]
+required-features = ["device-selected", "rt"] # stm32f746
 
 [[example]]
 name = "can-echo"

examples/pwm.rs

@@ -0,0 +1,33 @@
+//! Test the PWM
+
+//#![deny(warnings)]
+#![no_std]
+#![no_main]
+
+extern crate panic_semihosting;
+
+use cortex_m_rt::entry;
+
+use stm32f7xx_hal::{
+    pac,
+    prelude::*,
+};
+
+#[entry]
+fn main() -> ! {
+    let dp = pac::Peripherals::take().unwrap();
+
+    let rcc = dp.RCC.constrain();
+    let clocks = rcc.cfgr.freeze();
+
+    let gpioa = dp.GPIOA.split();
+    let channels = (gpioa.pa0.into_alternate(), gpioa.pa1.into_alternate());
+
+    let pwm = dp.TIM2.pwm(channels, 20_000u32.Hz(), &clocks);
+    let (mut ch1, _ch2) = pwm;
+    let max_duty = ch1.get_max_duty();
+    ch1.set_duty(max_duty / 4);
+    ch1.enable();
+
+    loop {}
+}

examples/timer.rs

@@ -17,6 +17,7 @@ use stm32f7xx_hal::{
     interrupt, pac,
     prelude::*,
     timer::{Event, Timer},
+    embedded_time::rate::Extensions,
 };
 
 #[entry]
@@ -32,7 +33,8 @@ fn main() -> ! {
     unsafe {
         NVIC::unmask(pac::Interrupt::TIM2);
     }
-    let mut timer = Timer::tim2(dp.TIM2, 1.Hz(), clocks, &mut rcc.apb1);
+    let mut timer = Timer::new(dp.TIM2, &clocks).count_down();
+    timer.start(1.Hz());
     timer.listen(Event::TimeOut);
 
     loop {}

src/i2c.rs

@@ -12,7 +12,7 @@ use crate::gpio::gpioh::{PH4, PH5, PH7, PH8};
 use crate::gpio::AlternateOD;
 use crate::hal::blocking::i2c::{Read, Write, WriteRead};
 use crate::pac::{DWT, I2C1, I2C2, I2C3};
-use crate::rcc::{Clocks, Enable, GetBusFreq, RccBus, Reset};
+use crate::rcc::{Clocks, Enable, BusClock, RccBus, Reset};
 use nb::Error::{Other, WouldBlock};
 use nb::{Error as NbError, Result as NbResult};
 
@@ -410,7 +410,7 @@ macro_rules! hal {
                     $I2CX::enable(apb);
                     $I2CX::reset(apb);
 
-                    let pclk = <$I2CX as RccBus>::Bus::get_frequency(&clocks).0;
+                    let pclk = <$I2CX as RccBus>::Bus::clock(&clocks).0;
 
                     let mut i2c = I2c { i2c, pins, mode, pclk };
                     i2c.init();

src/lib.rs

@@ -90,6 +90,9 @@ pub mod fmc_lcd;
 #[cfg(feature = "device-selected")]
 pub mod gpio;
 
+#[cfg(feature = "device-selected")]
+pub mod pwm;
+
 #[cfg(feature = "device-selected")]
 pub mod dac;
 

src/prelude.rs

@@ -5,6 +5,8 @@ pub use crate::fmc::FmcExt as _stm327xx_hal_fmc_FmcExt;
 
 pub use crate::gpio::GpioExt as _stm327xx_hal_gpio_GpioExt;
 pub use crate::hal::digital::v2::{InputPin, OutputPin};
+pub use crate::hal::timer::Cancel;
 pub use crate::hal::prelude::*;
+pub use crate::pwm::PwmExt as _stm32f7xx_hal_pwm_PwmExt;
 pub use crate::rcc::RccExt as _stm32f7xx_hal_rcc_RccExt;
 pub use crate::rng::RngExt as _;