From 62fdd309c55286222d1add4ca3051353da0e11b8 Mon Sep 17 00:00:00 2001
From: "Matthias P. Braendli" <matthias.braendli@mpb.li>
Date: Wed, 31 Mar 2021 17:40:53 +0200
Subject: Enable USB CDC ACM for eval-clock-cw-tx

---
 sw/eval-clock-cw-tx/src/main.rs | 14 +++++++
 sw/eval-clock-cw-tx/src/usb.rs  | 91 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 105 insertions(+)
 create mode 100644 sw/eval-clock-cw-tx/src/usb.rs

(limited to 'sw/eval-clock-cw-tx/src')

diff --git a/sw/eval-clock-cw-tx/src/main.rs b/sw/eval-clock-cw-tx/src/main.rs
index c91c545..d30318b 100644
--- a/sw/eval-clock-cw-tx/src/main.rs
+++ b/sw/eval-clock-cw-tx/src/main.rs
@@ -46,6 +46,7 @@ use embedded_hal::digital::v2::InputPin;
 use hd44780_driver::{Cursor, CursorBlink, Display, DisplayMode, HD44780};
 
 pub mod ui;
+pub mod usb;
 pub mod cw;
 pub mod state;
 pub mod si_clock;
@@ -92,8 +93,14 @@ fn main() -> ! {
     let mut rcc = dp.RCC.constrain();
     let mut afio = dp.AFIO.constrain(&mut rcc.apb2);
     let clocks = rcc.cfgr
+        .use_hse(16.mhz())
+        .sysclk(48.mhz())
+        .pclk1(24.mhz())
         .adcclk(2.mhz())
         .freeze(&mut flash.acr);
+
+    assert!(clocks.usbclk_valid());
+
     let mut delay = Delay::new(cp.SYST, clocks);
 
     delay.delay_ms(200u16);
@@ -102,6 +109,10 @@ fn main() -> ! {
     let mut gpiob = dp.GPIOB.split(&mut rcc.apb2);
     let mut gpioc = dp.GPIOC.split(&mut rcc.apb2);
 
+    let usb_dm = gpioa.pa11;
+    let usb_dp = gpioa.pa12.into_floating_input(&mut gpioa.crh);
+    let usb = usb::USB::new(dp.USB, usb_dm, usb_dp);
+
     // Buttons as analog inputs (multi-level)
     let pb0 = gpiob.pb0.into_floating_input(&mut gpiob.crl); // BTN1 Button B, has external pullup
     let pb1 = gpiob.pb1.into_floating_input(&mut gpiob.crl); // BTN0 Button A, has external pullup
@@ -173,6 +184,7 @@ fn main() -> ! {
     lcd.write_str(" 30m CW TX 2021 ", &mut delay).unwrap();
     delay.delay_ms(1_500u16);
 
+    usb.enable_interrupts();
 
     let mut siclock = {
         let shared = unsafe { &mut *SHARED.as_mut_ptr() };
@@ -349,6 +361,7 @@ fn TIM2() {
     }
 }
 
+#[allow(non_snake_case)]
 #[cortex_m_rt::exception]
 fn HardFault(ef: &ExceptionFrame) -> ! {
     let periph = unsafe { cortex_m::Peripherals::steal() };
@@ -360,6 +373,7 @@ fn HardFault(ef: &ExceptionFrame) -> ! {
     loop { }
 }
 
+#[allow(non_snake_case)]
 #[cortex_m_rt::exception]
 fn DefaultHandler(irqn: i16) {
     hprintln!("Unhandled exception (IRQn = {})", irqn).unwrap();
diff --git a/sw/eval-clock-cw-tx/src/usb.rs b/sw/eval-clock-cw-tx/src/usb.rs
new file mode 100644
index 0000000..941a024
--- /dev/null
+++ b/sw/eval-clock-cw-tx/src/usb.rs
@@ -0,0 +1,91 @@
+
+use stm32f1xx_hal::gpio;
+use stm32f1xx_hal::pac;
+use stm32f1xx_hal::pac::{interrupt, Interrupt};
+use stm32f1xx_hal::usb::{Peripheral, UsbBus, UsbBusType};
+use usb_device::{bus::UsbBusAllocator, prelude::*};
+use usbd_serial::{SerialPort, USB_CLASS_CDC};
+
+static mut USB_BUS: Option<UsbBusAllocator<UsbBusType>> = None;
+static mut USB_SERIAL: Option<usbd_serial::SerialPort<UsbBusType>> = None;
+static mut USB_DEVICE: Option<UsbDevice<UsbBusType>> = None;
+
+pub struct USB {
+}
+
+impl USB {
+    pub fn new(
+        usb: stm32f1xx_hal::pac::USB,
+        pin_dm: gpio::gpioa::PA11<gpio::Input<gpio::Floating>>,
+        pin_dp: gpio::gpioa::PA12<gpio::Input<gpio::Floating>>) -> Self {
+
+        let peripheral = Peripheral {
+            usb,
+            pin_dm,
+            pin_dp,
+        };
+
+        unsafe {
+            let bus = UsbBus::new(peripheral);
+
+            USB_BUS = Some(bus);
+
+            USB_SERIAL = Some(SerialPort::new(USB_BUS.as_ref().unwrap()));
+
+            let usb_dev = UsbDeviceBuilder::new(USB_BUS.as_ref().unwrap(), UsbVidPid(0x1d50, 0x5120)) // Openmoko Neo1973 serial
+                .manufacturer("HB9EGM")
+                .product("Beep Machine")
+                .serial_number("1")
+                .device_class(USB_CLASS_CDC)
+                .build();
+
+            USB_DEVICE = Some(usb_dev);
+        }
+
+        USB{}
+    }
+
+    pub fn enable_interrupts(&self) {
+        unsafe {
+            pac::NVIC::unmask(Interrupt::USB_HP_CAN_TX);
+            pac::NVIC::unmask(Interrupt::USB_LP_CAN_RX0);
+        }
+    }
+}
+
+#[allow(non_snake_case)]
+#[interrupt]
+fn USB_HP_CAN_TX() {
+    usb_interrupt();
+}
+
+#[allow(non_snake_case)]
+#[interrupt]
+fn USB_LP_CAN_RX0() {
+    usb_interrupt();
+}
+
+fn usb_interrupt() {
+    let usb_dev = unsafe { USB_DEVICE.as_mut().unwrap() };
+    let serial = unsafe { USB_SERIAL.as_mut().unwrap() };
+
+    if !usb_dev.poll(&mut [serial]) {
+        return;
+    }
+
+    let mut buf = [0u8; 8];
+
+    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;
+                }
+            }
+
+            serial.write(&buf[0..count]).ok();
+        }
+        _ => {}
+    }
+}
-- 
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