Implement USB support, inspiration taken from G4, F3, F4 and H7 hals

Author: usbalbin

Cargo.toml

@@ -70,6 +70,7 @@ embedded-hal = "1.0.0"
 defmt = { version = "1.0.0", optional = true }
 paste = "1.0.15"
 log = { version = "0.4.20", optional = true}
+stm32-usbd = "0.8.0"
 
 [dev-dependencies]
 log = { version = "0.4.20"}
@@ -85,6 +86,8 @@ cortex-m-semihosting = "0.5.0"
 panic-itm = { version = "~0.4.1" }
 panic-probe = "0.3.2"
 panic-semihosting = "0.6"
+usbd-serial = "0.2.2"
+usb-device = { version = "0.3.2", features = ["defmt", "log"] }
 
 [profile.release]
 codegen-units = 1 # better optimizations

examples/usb_serial.rs

@@ -0,0 +1,100 @@
+//! CDC-ACM serial port example using polling in a busy loop.
+#![deny(warnings)]
+#![deny(unsafe_code)]
+#![allow(clippy::uninlined_format_args)]
+#![no_std]
+#![no_main]
+
+use cortex_m_rt::entry;
+use hal::prelude::*;
+use hal::pwr::PwrExt;
+use hal::stm32;
+use stm32_usbd::UsbBus;
+use stm32h5xx_hal as hal;
+use stm32h5xx_hal::usb::UsbExt;
+
+use usb_device::prelude::*;
+use usbd_serial::{SerialPort, USB_CLASS_CDC};
+
+#[macro_use]
+mod utilities;
+
+use utilities::logger::info;
+
+#[entry]
+fn main() -> ! {
+    utilities::logger::init();
+
+    let dp = stm32::Peripherals::take().expect("cannot take peripherals");
+
+    let pwr = dp.PWR.constrain();
+    let pwrcfg = pwr.vos0().freeze();
+    // Constrain and Freeze clock
+    let rcc = dp.RCC.constrain();
+    let ccdr = rcc.sys_ck(250.MHz()).freeze(pwrcfg, &dp.SBS);
+
+    let gpioa = dp.GPIOA.split(ccdr.peripheral.GPIOA);
+
+    let mut led = gpioa.pa5.into_push_pull_output();
+    led.set_low();
+
+    let usb_dm = gpioa.pa11.into_alternate();
+    let usb_dp = gpioa.pa12.into_alternate();
+
+    let usb = dp.USB.usb(ccdr.peripheral.USB, usb_dm, usb_dp);
+    let usb_bus = UsbBus::new(usb);
+
+    let mut serial = SerialPort::new(&usb_bus);
+
+    let mut usb_dev =
+        UsbDeviceBuilder::new(&usb_bus, UsbVidPid(0x16c0, 0x27dd))
+            .strings(&[StringDescriptors::default()
+                .manufacturer("Fake company")
+                .product("Serial port")
+                .serial_number("TEST")])
+            .unwrap()
+            .device_class(USB_CLASS_CDC)
+            .build();
+
+    info!("Init done");
+
+    loop {
+        if !usb_dev.poll(&mut [&mut serial]) {
+            continue;
+        }
+
+        let mut buf = [0u8; 64];
+
+        match serial.read(&mut buf) {
+            Ok(count) if count > 0 => {
+                led.set_high();
+
+                if let Ok(s) = str::from_utf8(&buf[0..count]) {
+                    info!("{:?}", s);
+                } else {
+                    info!("{:?}", &buf[0..count]);
+                }
+
+                // Echo back in upper case
+                for c in buf[0..count].iter_mut() {
+                    if 0x61 <= *c && *c <= 0x7a {
+                        *c &= !0x20;
+                    }
+                }
+
+                let mut write_offset = 0;
+                while write_offset < count {
+                    match serial.write(&buf[write_offset..count]) {
+                        Ok(len) if len > 0 => {
+                            write_offset += len;
+                        }
+                        _ => {}
+                    }
+                }
+            }
+            _ => {}
+        }
+
+        led.set_low();
+    }
+}

src/lib.rs

@@ -79,6 +79,9 @@ pub mod spi;
 #[cfg(feature = "device-selected")]
 pub mod dwt;
 
+#[cfg(feature = "device-selected")]
+pub mod usb;
+
 #[cfg(feature = "device-selected")]
 mod sealed {
     pub trait Sealed {}

src/prelude.rs

@@ -8,6 +8,7 @@ pub use crate::icache::ICacheExt as _stm32h5xx_hal_icache_ICacheExt;
 pub use crate::pwr::PwrExt as _stm32h5xx_hal_pwr_PwrExt;
 pub use crate::rcc::RccExt as _stm32h5xx_hal_rcc_RccExt;
 pub use crate::spi::SpiExt as _stm32h5xx_hal_spi_SpiExt;
+pub use crate::usb::UsbExt as _stm32h5xx_hal_usb_UsbExt;
 
 pub use crate::time::U32Ext as _;
 pub use fugit::{ExtU32 as _, RateExtU32 as _};

src/usb.rs

@@ -0,0 +1,116 @@
+//! USB peripheral.
+//!
+//! Provides the required implementation for use of the [`stm32-usbd`] crate.
+
+use crate::stm32::rcc::ccipr4::USBSEL;
+pub use stm32_usbd::UsbBus;
+
+use crate::gpio;
+use crate::gpio::gpioa::{PA11, PA12};
+use crate::rcc::rec;
+use crate::stm32::{self, USB};
+use core::fmt;
+use stm32_usbd::UsbPeripheral;
+
+/// Type for pin that can be the "D-" pin for the USB peripheral
+pub type DmPin = PA11<gpio::Alternate<10>>;
+
+/// Type for pin that can be the "D+" pin for the USB peripheral
+pub type DpPin = PA12<gpio::Alternate<10>>;
+
+pub trait UsbExt {
+    fn usb(self, rec: rec::Usb, pin_dm: DmPin, pin_dp: DpPin) -> Peripheral;
+}
+
+impl UsbExt for stm32::USB {
+    fn usb(self, rec: rec::Usb, pin_dm: DmPin, pin_dp: DpPin) -> Peripheral {
+        if let USBSEL::Disable = rec.get_kernel_clk_mux() {
+            rec.kernel_clk_mux(USBSEL::Hsi48);
+        };
+
+        Peripheral {
+            _usb: self,
+            pin_dm,
+            pin_dp,
+        }
+    }
+}
+
+pub struct Peripheral {
+    /// USB register block
+    _usb: USB,
+    /// Data negative pin
+    pin_dm: DmPin,
+    /// Data positive pin
+    pin_dp: DpPin,
+}
+
+#[cfg(feature = "defmt")]
+impl defmt::Format for Peripheral {
+    fn format(&self, f: defmt::Formatter) {
+        defmt::write!(
+            f,
+            "Peripheral {{ usb: USB, pin_dm: {}, pin_dp: {}}}",
+            self.pin_dm,
+            self.pin_dp
+        );
+    }
+}
+
+impl fmt::Debug for Peripheral {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Peripheral")
+            .field("usb", &"USB")
+            .field("pin_dm", &self.pin_dm)
+            .field("pin_dp", &self.pin_dp)
+            .finish()
+    }
+}
+
+// SAFETY: Implementation of Peripheral is thread-safe by using cricitcal sections to ensure
+// mutually exclusive access to the USB peripheral
+unsafe impl Sync for Peripheral {}
+
+// SAFETY: The peripheral has the same regiter blockout as the STM32 USBFS
+unsafe impl UsbPeripheral for Peripheral {
+    const REGISTERS: *const () = USB::ptr().cast::<()>();
+    const DP_PULL_UP_FEATURE: bool = true;
+    const EP_MEMORY: *const () = 0x4001_6400 as _;
+    const EP_MEMORY_SIZE: usize = 2048;
+    const EP_MEMORY_ACCESS: stm32_usbd::MemoryAccess =
+        stm32_usbd::MemoryAccess::Word32x1;
+
+    fn enable() {
+        cortex_m::interrupt::free(|_| {
+            let rcc = unsafe { &*stm32::RCC::ptr() };
+
+            #[cfg(any(feature = "h523_h533", feature = "h56x_h573"))]
+            {
+                let pwr = unsafe { &*stm32::PWR::ptr() };
+
+                // Enable USB supply level detector
+                pwr.usbscr().modify(|_, w| w.usb33den().set_bit());
+
+                // Await good usb supply voltage
+                while pwr.vmsr().read().usb33rdy().bit_is_clear() {}
+
+                // Set bit to confirm that USB supply level is good
+                pwr.usbscr().modify(|_, w| w.usb33sv().set_bit());
+            }
+
+            // Enable USB peripheral
+            rcc.apb2enr().modify(|_, w| w.usben().set_bit());
+
+            // Reset USB peripheral
+            rcc.apb2rstr().modify(|_, w| w.usbrst().set_bit());
+            rcc.apb2rstr().modify(|_, w| w.usbrst().clear_bit());
+        });
+    }
+
+    fn startup_delay() {
+        // There is a chip specific startup delay. For STM32H503,523,533,56x and 573 it's
+        // 1µs and this should wait for at least that long.
+        // 250 Mhz is the highest frequency, so this ensures a minimum of 1µs wait time.
+        cortex_m::asm::delay(250);
+    }
+}