Merge pull request #56 from Disasm/usb

Add USB driver and example

Author: arkorobotics

.travis.yml

@@ -5,8 +5,8 @@ rust:
   - nightly
 env:
   - MCU=stm32l0x1
-  - MCU=stm32l0x2
-  - MCU=stm32l0x3
+  - MCU=stm32l0x2 FEATURES=stm32-usbd
+  - MCU=stm32l0x3 FEATURES=stm32-usbd
 matrix:
   allow_failures:
     - rust: nightly
@@ -47,4 +47,4 @@ matrix:
 before_script:
   - rustup target add thumbv6m-none-eabi
 script:
-  - RUSTFLAGS="-D warnings" cargo build --release --examples --features="rt $MCU $PACKAGE"
+  - RUSTFLAGS="-D warnings" cargo build --release --examples --features="rt $MCU $PACKAGE $FEATURES"

Cargo.toml

@@ -24,7 +24,7 @@ repository = "https://github.com/stm32-rs/stm32l0xx-hal"
 version = "0.4.0"
 
 [package.metadata.docs.rs]
-features = ["stm32l0x1", "rt"]
+features = ["stm32l0x2", "rt", "stm32-usbd"]
 
 [dependencies]
 as-slice = "0.1.0"
@@ -35,6 +35,7 @@ cortex-m-semihosting = "0.3.2"
 void = { version = "1.0.2", default-features = false }
 cast = { version = "0.2.2", default-features = false }
 nb = "0.1.2"
+stm32-usbd = { version = "0.5.0", features = ["ram_access_2x16"], optional = true }
 
 [dependencies.stm32l0]
 version = "0.8.0"
@@ -45,6 +46,8 @@ heapless = "0.5.0"
 panic-halt = "0.2.0"
 panic-semihosting = "0.5.1"
 cortex-m-rtfm = "0.4.3"
+usb-device = "0.2.3"
+usbd-serial = "0.1.0"
 
 [features]
 # Miscellaneaous features
@@ -141,3 +144,7 @@ required-features = ["rt"]
 [[example]]
 name = "adc_pwm"
 required-features = ["stm32l0x1"]
+
+[[example]]
+name = "usb_serial"
+required-features = ["rt", "stm32l0x2", "stm32-usbd"]

examples/usb_serial.rs

@@ -0,0 +1,68 @@
+//! CDC-ACM serial port example using polling in a busy loop.
+#![no_std]
+#![no_main]
+
+extern crate panic_semihosting;
+
+use cortex_m_rt::entry;
+use stm32l0xx_hal::usb::{Peripheral, UsbBus};
+use stm32l0xx_hal::{pac, prelude::*, rcc, syscfg::SYSCFG};
+use usb_device::prelude::*;
+use usbd_serial::{SerialPort, USB_CLASS_CDC};
+
+#[entry]
+fn main() -> ! {
+    let dp = pac::Peripherals::take().unwrap();
+
+    let mut rcc = dp.RCC.freeze(rcc::Config::hsi16());
+    let mut syscfg = SYSCFG::new(dp.SYSCFG_COMP, &mut rcc);
+    rcc.enable_hsi48(&mut syscfg, dp.CRS);
+
+    let gpioa = dp.GPIOA.split(&mut rcc);
+
+    let usb = Peripheral {
+        usb: dp.USB,
+        pin_dm: gpioa.pa11,
+        pin_dp: gpioa.pa12,
+    };
+    let usb_bus = UsbBus::new(usb);
+
+    let mut serial = SerialPort::new(&usb_bus);
+
+    let mut usb_dev = UsbDeviceBuilder::new(&usb_bus, UsbVidPid(0x16c0, 0x27dd))
+        .manufacturer("Fake company")
+        .product("Serial port")
+        .serial_number("TEST")
+        .device_class(USB_CLASS_CDC)
+        .build();
+
+    loop {
+        if !usb_dev.poll(&mut [&mut serial]) {
+            continue;
+        }
+
+        let mut buf = [0u8; 64];
+
+        match serial.read(&mut buf) {
+            Ok(count) if count > 0 => {
+                // 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;
+                        }
+                        _ => {}
+                    }
+                }
+            }
+            _ => {}
+        }
+    }
+}

src/lib.rs

@@ -41,6 +41,6 @@ pub mod spi;
 pub mod syscfg;
 pub mod time;
 pub mod timer;
-#[cfg(any(feature = "stm32l0x2", feature = "stm32l0x3"))]
+#[cfg(all(feature = "stm32-usbd", any(feature = "stm32l0x2", feature = "stm32l0x3")))]
 pub mod usb;
 pub mod watchdog;

src/usb.rs

@@ -1,39 +1,56 @@
-//! Support code for working with the USB peripheral
+//! Interface to the USB peripheral
 //!
-//! This module is different from the other peripheral APIs, in the sense that
-//! it isn't really a peripheral API, just some support code to make working
-//! with the USB peripheral possible. This is due to the existing STM32
-//! ecosystem support for USB.
+//! Requires the `stm32-usbd` feature.
 //!
 //! As USB seems to work mostly the same across all STM32 MCUs, there is a
-//! single crates that supports USB for these MCUs:
+//! single crate that supports USB for these MCUs:
 //! [`stm32-usbd`](https://crates.io/crates/stm32-usbd)
 //!
-//! Since `stm32-usbd` depends on the HAL libraries for each STM32 family it
-//! supports, we can't exactly depend on it to provide everything you need here.
-//! Instead, we just provide some code that takes care of the platform-specific
-//! bits, which you can call before using `stm32-usbd` for the rest.
+//! This module implements some bits needed for `stm32-usbd` to work and exports
+//! `UsbBus` from `stm32-usbd`.
 //!
 //! Please check out the USB examples in the `examples/` directory to see how it
 //! fits together.
 
+use crate::stm32::{RCC, USB};
+use stm32_usbd::UsbPeripheral;
 
-use crate::rcc::{
-    HSI48,
-    Rcc,
-};
+use crate::gpio::gpioa::{PA11, PA12};
+use crate::gpio::{Floating, Input};
+pub use stm32_usbd::UsbBus;
 
+pub struct Peripheral {
+    pub usb: USB,
+    pub pin_dm: PA11<Input<Floating>>,
+    pub pin_dp: PA12<Input<Floating>>,
+}
+
+unsafe impl Sync for Peripheral {}
+
+unsafe impl UsbPeripheral for Peripheral {
+    const REGISTERS: *const () = USB::ptr() as *const ();
+    const DP_PULL_UP_FEATURE: bool = true;
+    const EP_MEMORY: *const () = 0x4000_6000 as _;
+    const EP_MEMORY_SIZE: usize = 1024;
 
-/// Initializes the USB peripheral
-///
-/// This method takes care of the platform-specific bits of the USB
-/// initialization. After calling this method, you need `stm32-usbd` to actually
-/// do anything useful with the USB peripheral.
-pub fn init(rcc: &mut Rcc, _: HSI48) {
-    // Reset USB peripheral
-    rcc.rb.apb1rstr.modify(|_, w| w.usbrst().set_bit());
-    rcc.rb.apb1rstr.modify(|_, w| w.usbrst().clear_bit());
+    fn enable() {
+        let rcc = unsafe { (&*RCC::ptr()) };
 
-    // We don't need to enable the USB peripheral, as stm32-usbd takes care of
-    // that.
+        cortex_m::interrupt::free(|_| {
+            // Enable USB peripheral
+            rcc.apb1enr.modify(|_, w| w.usben().set_bit());
+
+            // Reset USB peripheral
+            rcc.apb1rstr.modify(|_, w| w.usbrst().set_bit());
+            rcc.apb1rstr.modify(|_, w| w.usbrst().clear_bit());
+        });
+    }
+
+    fn startup_delay() {
+        // There is a chip specific startup delay. For STM32L0x2/x3 it's 1µs and this should wait for
+        // at least that long.
+        cortex_m::asm::delay(32);
+    }
 }
+
+pub type UsbBusType = UsbBus<Peripheral>;