feat(nrf): add rtc support for nRF54L

Signed-off-by: Haobo Gu <haobogu@outlook.com>

embassy-nrf/Cargo.toml

@@ -80,6 +80,8 @@ unstable-pac = []
 gpiote = []
 
 ## Use RTC1 as the time driver for `embassy-time`, with a tick rate of 32.768khz
+## 
+## Note: For nRF54L, it's actually RTC30
 time-driver-rtc1 = ["_time-driver"]
 
 ## Enable embassy-net 802.15.4 driver

embassy-nrf/src/chips/nrf54l15_app.rs

@@ -249,6 +249,45 @@ embassy_hal_internal::peripherals! {
     P2_09,
     P2_10,
 
+    // RTC
+    RTC10,
+    RTC30,
+
+    // SERIAL
+    SERIAL00,
+    SERIAL20,
+    SERIAL21,
+    SERIAL22,
+    SERIAL30,
+
+    // SAADC
+    SAADC,
+
+    // RADIO
+    RADIO,
+
+    // TIMER
+    TIMER00,
+    TIMER10,
+    TIMER20,
+
+    // PPI BRIDGE
+    PPIB00,
+    PPIB01,
+    PPIB10,
+    PPIB11,
+    PPIB20,
+    PPIB21,
+    PPIB22,
+    PPIB30,
+
+    // GPIOTE
+    GPIOTE20,
+    GPIOTE30,
+
+    // CRACEN
+    CRACEN,
+
     #[cfg(feature = "_s")]
     // RRAMC
     RRAMC,
@@ -303,6 +342,9 @@ impl_pin!(P2_08, 2, 8);
 impl_pin!(P2_09, 2, 9);
 impl_pin!(P2_10, 2, 10);
 
+impl_rtc!(RTC10, RTC10, RTC10);
+impl_rtc!(RTC30, RTC30, RTC30);
+
 #[cfg(feature = "_ns")]
 impl_wdt!(WDT, WDT31, WDT31, 0);
 #[cfg(feature = "_s")]

embassy-nrf/src/lib.rs

@@ -155,7 +155,6 @@ pub mod reset;
 #[cfg(not(feature = "_nrf54l"))] // TODO
 #[cfg(not(any(feature = "_nrf5340-app", feature = "_nrf91")))]
 pub mod rng;
-#[cfg(not(feature = "_nrf54l"))] // TODO
 pub mod rtc;
 #[cfg(not(feature = "_nrf54l"))] // TODO
 #[cfg(not(any(feature = "_nrf51", feature = "nrf52820", feature = "_nrf5340-net")))]

examples/nrf54l15/Cargo.toml

@@ -8,6 +8,7 @@ publish = false
 [dependencies]
 embassy-executor = { version = "0.9.0", path = "../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "executor-interrupt", "defmt"] }
 embassy-time = { version = "0.5.0", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime"] }
+embassy-sync = { version = "0.7.2", path = "../../embassy-sync", features = ["defmt"] }
 embassy-nrf = { version = "0.8.0", path = "../../embassy-nrf", features = ["defmt", "nrf54l15-app-s", "time-driver-rtc1", "gpiote", "unstable-pac", "time"] }
 
 defmt = "1.0.1"
@@ -18,6 +19,7 @@ cortex-m = { version = "0.7.6", features = ["inline-asm", "critical-section-sing
 cortex-m-rt = "0.7.0"
 
 embedded-storage = "0.3.1"
+portable-atomic = "1"
 
 [profile.release]
 debug = 2

examples/nrf54l15/src/bin/rtc.rs

@@ -0,0 +1,56 @@
+#![no_std]
+#![no_main]
+
+use core::cell::RefCell;
+
+use embassy_executor::Spawner;
+use embassy_nrf::gpio::{Level, Output, OutputDrive};
+use embassy_nrf::interrupt;
+use embassy_nrf::rtc::Rtc;
+use embassy_sync::blocking_mutex::Mutex;
+use embassy_sync::blocking_mutex::raw::CriticalSectionRawMutex;
+use portable_atomic::AtomicU64;
+use {defmt_rtt as _, panic_probe as _};
+
+// 64 bit counter which will never overflow.
+static TICK_COUNTER: AtomicU64 = AtomicU64::new(0);
+static RTC: Mutex<CriticalSectionRawMutex, RefCell<Option<Rtc<'static>>>> = Mutex::new(RefCell::new(None));
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    defmt::println!("nRF54L15 RTC example");
+    let p = embassy_nrf::init(Default::default());
+    let mut led = Output::new(p.P2_09, Level::High, OutputDrive::Standard);
+    // Counter resolution is 125 ms.
+    let mut rtc = Rtc::new(p.RTC10, (1 << 12) - 1).unwrap();
+    rtc.enable_interrupt(embassy_nrf::rtc::Interrupt::Tick, true);
+    rtc.enable_event(embassy_nrf::rtc::Interrupt::Tick);
+    rtc.enable();
+    RTC.lock(|r| {
+        let mut rtc_borrow = r.borrow_mut();
+        *rtc_borrow = Some(rtc);
+    });
+
+    let mut last_counter_val = 0;
+    loop {
+        let current = TICK_COUNTER.load(core::sync::atomic::Ordering::Relaxed);
+        if current != last_counter_val {
+            led.toggle();
+            last_counter_val = current;
+        }
+    }
+}
+
+#[interrupt]
+fn RTC10() {
+    // For 64-bit, we do not need to worry about overflowing, at least not for realistic program
+    // lifetimes.
+    TICK_COUNTER.fetch_add(1, core::sync::atomic::Ordering::Relaxed);
+    RTC.lock(|r| {
+        let mut rtc_borrow = r.borrow_mut();
+        rtc_borrow
+            .as_mut()
+            .unwrap()
+            .reset_event(embassy_nrf::rtc::Interrupt::Tick);
+    });
+}