Do not reset UsbSerialJtag peripheral (#1961)

* Fix typos

* Add a function to detect debugger connection

* Do not reset USB peripheral

* Changelog

* Fix different register names

* Reuse xtensa_lx::is_debugger_attached

esp-hal/CHANGELOG.md

@@ -13,7 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added touch pad support for esp32 (#1873, #1956)
 - Allow configuration of period updating method for MCPWM timers (#1898)
 - Add self-testing mode for TWAI peripheral. (#1929)
-- Added a `PeripheralClockControl::reset` to the driver constructors where missing (#1893)
+- Added `debugger::debugger_connected`. (#1961)
 
 ### Changed
 
@@ -23,6 +23,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Allow DMA to/from psram for esp32s3 (#1827)
 - DMA buffers now don't require a static lifetime. Make sure to never `mem::forget` an in-progress DMA transfer (consider using `#[deny(clippy::mem_forget)]`) (#1837)
 - Peripherals (where possible) are now explicitly reset and enabled in their constructors (#1893)
+- Reset peripherals in driver constructors where missing (#1893, #1961)
 
 ### Fixed
 

esp-hal/src/assist_debug.rs

@@ -68,7 +68,7 @@ impl<'d> InterruptConfigurable for DebugAssist<'d> {
 #[cfg(assist_debug_sp_monitor)]
 impl<'d> DebugAssist<'d> {
     /// Enable SP monitoring on main core. When the SP exceeds the
-    /// `lower_bound` or `upper_bound` treshold, the module will record the PC
+    /// `lower_bound` or `upper_bound` threshold, the module will record the PC
     /// pointer and generate an interrupt.
     pub fn enable_sp_monitor(&mut self, lower_bound: u32, upper_bound: u32) {
         self.debug_assist
@@ -150,8 +150,8 @@ impl<'d> DebugAssist<'d> {
 
 #[cfg(all(assist_debug_sp_monitor, multi_core))]
 impl<'d> DebugAssist<'d> {
-    /// Enable SP monitoring on secondondary core. When the SP exceeds the
+    /// Enable SP monitoring on secondary core. When the SP exceeds the
-    /// `lower_bound` or `upper_bound` treshold, the module will record the PC
+    /// `lower_bound` or `upper_bound` threshold, the module will record the PC
     /// pointer and generate an interrupt.
     pub fn enable_core1_sp_monitor(&mut self, lower_bound: u32, upper_bound: u32) {
         self.debug_assist
@@ -384,7 +384,7 @@ impl<'d> DebugAssist<'d> {
                 .bit_is_set()
     }
 
-    /// Get region monotoring PC value on main core.
+    /// Get region monitoring PC value on main core.
     pub fn get_region_monitor_pc(&self) -> u32 {
         self.debug_assist
             .core_0_area_pc()
@@ -550,7 +550,7 @@ impl<'d> DebugAssist<'d> {
                 .bit_is_set()
     }
 
-    /// Get region monotoring PC value on secondary core.
+    /// Get region monitoring PC value on secondary core.
     pub fn get_core1_region_monitor_pc(&self) -> u32 {
         self.debug_assist
             .core_1_area_pc()

esp-hal/src/debugger.rs

@@ -0,0 +1,36 @@
+//! Debugger utilities
+
+/// Checks if a debugger is connected.
+pub fn debugger_connected() -> bool {
+    #[cfg(xtensa)]
+    {
+        xtensa_lx::is_debugger_attached()
+    }
+
+    #[cfg(riscv)]
+    {
+        use crate::peripherals::ASSIST_DEBUG;
+        let assist_debug = unsafe { &*ASSIST_DEBUG::ptr() };
+        #[cfg(feature = "esp32c2")]
+        {
+            assist_debug
+                .core_0_debug_mode()
+                .read()
+                .core_0_debug_module_active()
+                .bit_is_set()
+        }
+        #[cfg(not(feature = "esp32c2"))]
+        {
+            assist_debug
+                .c0re_0_debug_mode()
+                .read()
+                .core_0_debug_module_active()
+                .bit_is_set()
+        }
+    }
+
+    #[cfg(not(any(xtensa, riscv)))]
+    {
+        false
+    }
+}

esp-hal/src/lib.rs

@@ -241,6 +241,8 @@ pub mod uart;
 #[cfg(usb_device)]
 pub mod usb_serial_jtag;
 
+pub mod debugger;
+
 /// State of the CPU saved when entering exception or interrupt
 pub mod trapframe {
     #[cfg(riscv)]

esp-hal/src/usb_serial_jtag.rs

@@ -273,7 +273,8 @@ where
     M: Mode,
 {
     fn new_inner(_usb_device: impl Peripheral<P = USB_DEVICE> + 'd) -> Self {
-        PeripheralClockControl::reset(crate::system::Peripheral::UsbDevice);
+        // Do NOT reset the peripheral. Doing so will result in a broken USB JTAG
+        // connection.
         PeripheralClockControl::enable(crate::system::Peripheral::UsbDevice);
 
         USB_DEVICE::disable_tx_interrupts();
@@ -311,7 +312,7 @@ where
     }
 
     /// Split the USB Serial JTAG peripheral into a transmitter and receiver,
-    /// which is particuarly useful when having two tasks correlating to
+    /// which is particularly useful when having two tasks correlating to
     /// transmitting and receiving.
     pub fn split(self) -> (UsbSerialJtagTx<'d, M>, UsbSerialJtagRx<'d, M>) {
         (self.tx, self.rx)

hil-test/Cargo.toml

@@ -100,6 +100,10 @@ harness = false
 name    = "uart"
 harness = false
 
+[[test]]
+name    = "usb_serial_jtag"
+harness = false
+
 [[test]]
 name              = "uart_async"
 harness           = false

hil-test/tests/usb_serial_jtag.rs

@@ -0,0 +1,45 @@
+//! USB Serial JTAG tests
+
+//% CHIPS: esp32c3 esp32c6 esp32h2 esp32s3
+
+#![no_std]
+#![no_main]
+
+#[cfg(test)]
+#[embedded_test::tests]
+mod tests {
+    use defmt_rtt as _;
+    use esp_backtrace as _;
+    use esp_hal::{
+        clock::ClockControl,
+        peripherals::Peripherals,
+        system::SystemControl,
+        timer::{timg::TimerGroup, ErasedTimer, OneShotTimer},
+        usb_serial_jtag::UsbSerialJtag,
+    };
+
+    // When you are okay with using a nightly compiler it's better to use https://docs.rs/static_cell/2.1.0/static_cell/macro.make_static.html
+    macro_rules! mk_static {
+        ($t:ty,$val:expr) => {{
+            static STATIC_CELL: static_cell::StaticCell<$t> = static_cell::StaticCell::new();
+            #[deny(unused_attributes)]
+            let x = STATIC_CELL.uninit().write(($val));
+            x
+        }};
+    }
+
+    #[test]
+    fn creating_peripheral_does_not_break_debug_connection() {
+        let peripherals = Peripherals::take();
+        let system = SystemControl::new(peripherals.SYSTEM);
+        let clocks = ClockControl::boot_defaults(system.clock_control).freeze();
+
+        let timg0 = TimerGroup::new(peripherals.TIMG0, &clocks);
+        let timer0: ErasedTimer = timg0.timer0.into();
+        let timers = [OneShotTimer::new(timer0)];
+        let timers = mk_static!([OneShotTimer<ErasedTimer>; 1], timers);
+        esp_hal_embassy::init(&clocks, timers);
+
+        _ = UsbSerialJtag::new_async(peripherals.USB_DEVICE).split();
+    }
+}