rtc: Add RWDT examples for ESP32, ESP32-S2 and ESP32-S3

Signed-off-by: Gustavo Henrique Nihei <gustavo.nihei@espressif.com>

esp32-hal/examples/rtc_watchdog.rs

@@ -0,0 +1,66 @@
+//! This demos the RTC Watchdog Timer (RWDT).
+//! The RWDT is initially configured to trigger an interrupt after a given
+//! timeout. Then, upon expiration, the RWDT is restarted and then reconfigured
+//! to reset both the main system and the RTC.
+
+#![no_std]
+#![no_main]
+
+use core::cell::RefCell;
+
+use esp32_hal::{
+    clock::ClockControl,
+    interrupt,
+    pac::{self, Peripherals},
+    prelude::*,
+    Rtc,
+};
+use esp_hal_common::Rwdt;
+use panic_halt as _;
+use xtensa_lx::mutex::{CriticalSectionMutex, Mutex};
+use xtensa_lx_rt::entry;
+
+static mut RWDT: CriticalSectionMutex<RefCell<Option<Rwdt>>> =
+    CriticalSectionMutex::new(RefCell::new(None));
+
+#[entry]
+fn main() -> ! {
+    let peripherals = Peripherals::take().unwrap();
+    let system = peripherals.DPORT.split();
+    let _clocks = ClockControl::boot_defaults(system.clock_control).freeze();
+
+    let mut rtc = Rtc::new(peripherals.RTC_CNTL);
+
+    // Disable watchdog timer
+    rtc.rwdt.disable();
+
+    rtc.rwdt.start(2000u64.millis());
+    rtc.rwdt.listen();
+
+    interrupt::enable(pac::Interrupt::RTC_CORE, interrupt::Priority::Priority1).unwrap();
+
+    unsafe {
+        (&RWDT).lock(|data| (*data).replace(Some(rtc.rwdt)));
+    }
+
+    loop {}
+}
+
+#[interrupt]
+fn RTC_CORE() {
+    unsafe {
+        (&RWDT).lock(|data| {
+            esp_println::println!("RWDT Interrupt");
+
+            let mut rwdt = data.borrow_mut();
+            let rwdt = rwdt.as_mut().unwrap();
+
+            rwdt.clear_interrupt();
+
+            esp_println::println!("Restarting in 5 seconds...");
+
+            rwdt.start(5000u64.millis());
+            rwdt.unlisten();
+        });
+    }
+}

esp32s2-hal/examples/rtc_watchdog.rs

@@ -0,0 +1,66 @@
+//! This demos the RTC Watchdog Timer (RWDT).
+//! The RWDT is initially configured to trigger an interrupt after a given
+//! timeout. Then, upon expiration, the RWDT is restarted and then reconfigured
+//! to reset both the main system and the RTC.
+
+#![no_std]
+#![no_main]
+
+use core::cell::RefCell;
+
+use esp32s2_hal::{
+    clock::ClockControl,
+    interrupt,
+    pac::{self, Peripherals},
+    prelude::*,
+    Rtc,
+};
+use esp_hal_common::Rwdt;
+use panic_halt as _;
+use xtensa_lx::mutex::{CriticalSectionMutex, Mutex};
+use xtensa_lx_rt::entry;
+
+static mut RWDT: CriticalSectionMutex<RefCell<Option<Rwdt>>> =
+    CriticalSectionMutex::new(RefCell::new(None));
+
+#[entry]
+fn main() -> ! {
+    let peripherals = Peripherals::take().unwrap();
+    let system = peripherals.SYSTEM.split();
+    let _clocks = ClockControl::boot_defaults(system.clock_control).freeze();
+
+    let mut rtc = Rtc::new(peripherals.RTC_CNTL);
+
+    // Disable watchdog timer
+    rtc.rwdt.disable();
+
+    rtc.rwdt.start(2000u64.millis());
+    rtc.rwdt.listen();
+
+    interrupt::enable(pac::Interrupt::RTC_CORE, interrupt::Priority::Priority1).unwrap();
+
+    unsafe {
+        (&RWDT).lock(|data| (*data).replace(Some(rtc.rwdt)));
+    }
+
+    loop {}
+}
+
+#[interrupt]
+fn RTC_CORE() {
+    unsafe {
+        (&RWDT).lock(|data| {
+            esp_println::println!("RWDT Interrupt");
+
+            let mut rwdt = data.borrow_mut();
+            let rwdt = rwdt.as_mut().unwrap();
+
+            rwdt.clear_interrupt();
+
+            esp_println::println!("Restarting in 5 seconds...");
+
+            rwdt.start(5000u64.millis());
+            rwdt.unlisten();
+        });
+    }
+}

esp32s3-hal/examples/rtc_watchdog.rs

@@ -0,0 +1,66 @@
+//! This demos the RTC Watchdog Timer (RWDT).
+//! The RWDT is initially configured to trigger an interrupt after a given
+//! timeout. Then, upon expiration, the RWDT is restarted and then reconfigured
+//! to reset both the main system and the RTC.
+
+#![no_std]
+#![no_main]
+
+use core::cell::RefCell;
+
+use esp32s3_hal::{
+    clock::ClockControl,
+    interrupt,
+    pac::{self, Peripherals},
+    prelude::*,
+    Rtc,
+};
+use esp_hal_common::Rwdt;
+use panic_halt as _;
+use xtensa_lx::mutex::{CriticalSectionMutex, Mutex};
+use xtensa_lx_rt::entry;
+
+static mut RWDT: CriticalSectionMutex<RefCell<Option<Rwdt>>> =
+    CriticalSectionMutex::new(RefCell::new(None));
+
+#[entry]
+fn main() -> ! {
+    let peripherals = Peripherals::take().unwrap();
+    let system = peripherals.SYSTEM.split();
+    let _clocks = ClockControl::boot_defaults(system.clock_control).freeze();
+
+    let mut rtc = Rtc::new(peripherals.RTC_CNTL);
+
+    // Disable watchdog timer
+    rtc.rwdt.disable();
+
+    rtc.rwdt.start(2000u64.millis());
+    rtc.rwdt.listen();
+
+    interrupt::enable(pac::Interrupt::RTC_CORE, interrupt::Priority::Priority1).unwrap();
+
+    unsafe {
+        (&RWDT).lock(|data| (*data).replace(Some(rtc.rwdt)));
+    }
+
+    loop {}
+}
+
+#[interrupt]
+fn RTC_CORE() {
+    unsafe {
+        (&RWDT).lock(|data| {
+            esp_println::println!("RWDT Interrupt");
+
+            let mut rwdt = data.borrow_mut();
+            let rwdt = rwdt.as_mut().unwrap();
+
+            rwdt.clear_interrupt();
+
+            esp_println::println!("Restarting in 5 seconds...");
+
+            rwdt.start(5000u64.millis());
+            rwdt.unlisten();
+        });
+    }
+}