From 434e2b3d212cf1886b8d8d337022726e2eda0c03 Mon Sep 17 00:00:00 2001
From: Priec <filippriec@gmail.com>
Date: Wed, 3 Dec 2025 17:57:10 +0100
Subject: [PATCH] shutdown added

---
 semestralka_2/src/bin/main.rs       | 15 ++++-----------
 semestralka_2/src/sleep/mod.rs      |  1 +
 semestralka_2/src/sleep/shutdown.rs | 13 +++++++++++++
 semestralka_2/src/wakeup/iwdg.rs    | 14 ++++++++++++++
 4 files changed, 32 insertions(+), 11 deletions(-)
 create mode 100644 semestralka_2/src/sleep/shutdown.rs

diff --git a/semestralka_2/src/bin/main.rs b/semestralka_2/src/bin/main.rs
index eb6fdd9..93e831e 100644
--- a/semestralka_2/src/bin/main.rs
+++ b/semestralka_2/src/bin/main.rs
@@ -19,16 +19,13 @@ use dma_gpio::config::{
 };
 use dma_gpio::hw_uart_pc::{driver::uart_task, usart1};
 use dma_gpio::wakeup::iwdg::{clear_wakeup_flags, init_watchdog};
+use dma_gpio::sleep::shutdown::enter_shutdown;
 use {defmt_rtt as _, panic_probe as _};
 
 bind_interrupts!(struct Irqs {
     USART1 => BufferedInterruptHandler<peripherals::USART1>;
 });
 
-unsafe extern "C" {
-    fn HAL_PWR_EnterSTANDBYMode();
-}
-
 #[embassy_executor::main]
 async fn main(spawner: Spawner) {
     info!("boot");
@@ -65,18 +62,14 @@ async fn main(spawner: Spawner) {
     info!("DBGMCU CR: dbg_stop={}, dbg_standby={}", cr.dbg_stop(), cr.dbg_standby());
 
     // MAIN LOOP
-    info!("Preparing for standby...");
     Timer::after(Duration::from_millis(500)).await;
 
-    init_watchdog(p.IWDG).await;
+    // init_watchdog(p.IWDG).await;
     Timer::after(Duration::from_millis(10)).await;
-                        
-    unsafe {
-        info!("Standby...");
-        HAL_PWR_EnterSTANDBYMode();
-    }
 
     loop {
+        info!("entering shutdown");
+        enter_shutdown();
         cortex_m::asm::wfi();
         yield_now().await;
     }
diff --git a/semestralka_2/src/sleep/mod.rs b/semestralka_2/src/sleep/mod.rs
index d57c64f..eec9227 100644
--- a/semestralka_2/src/sleep/mod.rs
+++ b/semestralka_2/src/sleep/mod.rs
@@ -1,3 +1,4 @@
 // src/sleep/mod.rs
 
 pub mod standby;
+pub mod shutdown;
diff --git a/semestralka_2/src/sleep/shutdown.rs b/semestralka_2/src/sleep/shutdown.rs
new file mode 100644
index 0000000..44bc0b3
--- /dev/null
+++ b/semestralka_2/src/sleep/shutdown.rs
@@ -0,0 +1,13 @@
+// src/sleep/standby.rs
+
+pub fn enter_shutdown() -> ! {
+    unsafe extern "C" {
+        fn HAL_PWREx_EnterSHUTDOWNMode();
+    }
+
+    unsafe {
+        HAL_PWREx_EnterSHUTDOWNMode();
+    }
+
+    cortex_m::asm::udf(); //panic
+}
diff --git a/semestralka_2/src/wakeup/iwdg.rs b/semestralka_2/src/wakeup/iwdg.rs
index 977d7af..b9ccb33 100644
--- a/semestralka_2/src/wakeup/iwdg.rs
+++ b/semestralka_2/src/wakeup/iwdg.rs
@@ -9,6 +9,15 @@ use embassy_stm32::pac;
 
 use crate::config::WATCHDOG_TIMEOUT_US;
 
+/// Clears system reset and standby flags after wakeup.
+///
+/// Call early in startup to:
+/// - Clear reset flags by setting `RMVF` in `RCC_CSR`.
+/// - If `SBF` in `PWR_SR` is set (woke from Standby), clear it.
+///
+/// # Registers
+/// - `RCC_CSR` — Reset and Clock Control / Status
+/// - `PWR_SR` — Power Control / Status
 pub fn clear_wakeup_flags() {
     info!("Clearing wakeup flags...");
 
@@ -26,6 +35,11 @@ pub fn clear_wakeup_flags() {
     }
 }
 
+/// Initializes the Independent Watchdog (IWDG) timer.
+/// Wakeup source: Can wake the system from Standby mode on timeout
+///
+/// # Timing
+/// - Timeout value is configured in `WATCHDOG_TIMEOUT_US` from config.rs
 pub async fn init_watchdog(iwdg: Peri<'_, peripherals::IWDG>) {
     info!("Initializing watchdog after watchdog wake...");
     let mut watchdog = IndependentWatchdog::new(iwdg, WATCHDOG_TIMEOUT_US);