3 files changed, 347 insertions, 0 deletions

diff --git a/embassy-mspm0/build.rs b/embassy-mspm0/build.rs
index efbe6645f..256192f8b 100644
--- a/embassy-mspm0/build.rs
+++ b/embassy-mspm0/build.rs
@@ -554,6 +554,7 @@ fn generate_peripheral_instances() -> TokenStream {
         let tokens = match peripheral.kind {
             "uart" => Some(quote! { impl_uart_instance!(#peri); }),
             "i2c" => Some(quote! { impl_i2c_instance!(#peri, #fifo_size); }),
+            "wwdt" => Some(quote! { impl_wwdt_instance!(#peri); }),
             _ => None,
         };
 
diff --git a/embassy-mspm0/src/lib.rs b/embassy-mspm0/src/lib.rs
index 6217669d2..8ee182c12 100644
--- a/embassy-mspm0/src/lib.rs
+++ b/embassy-mspm0/src/lib.rs
@@ -18,6 +18,7 @@ pub mod gpio;
 pub mod i2c;
 pub mod timer;
 pub mod uart;
+pub mod watchdog;
 
 /// Operating modes for peripherals.
 pub mod mode {
diff --git a/embassy-mspm0/src/watchdog.rs b/embassy-mspm0/src/watchdog.rs
new file mode 100644
index 000000000..95e5b97f3
--- /dev/null
+++ b/embassy-mspm0/src/watchdog.rs
@@ -0,0 +1,345 @@
+//! Window Watchdog Timer (WWDT) driver.
+//!
+//! This HAL implements a basic window watchdog timer with handles.
+
+#![macro_use]
+
+use core::marker::PhantomData;
+
+use embassy_hal_internal::PeripheralType;
+
+use crate::pac::wwdt::{vals, Wwdt as Regs};
+use crate::pac::{self};
+use crate::Peri;
+
+/// Possible watchdog timeout values.
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum Timeout {
+    USec1950,
+    USec3910,
+    USec5860,
+    USec7810,
+    USec9770,
+    USec11720,
+    USec13670,
+    USec15630,
+    USec23440,
+    USec31250,
+    USec32250,
+    USec39060,
+    USec46880,
+    USec54690,
+    USec62500,
+    USec93750,
+    USec125000,
+    USec156250,
+    USec187500,
+    USec218750,
+    MSec130,
+    MSec250,
+    MSec380,
+    MSec500,
+    MSec630,
+    MSec750,
+    MSec880,
+    Sec1,
+    Sec2,
+    Sec3,
+    Sec4,
+    Sec5,
+    Sec6,
+    Sec7,
+    Sec8,
+    Sec16,
+    Sec24,
+    Sec32,
+    Sec40,
+    Sec48,
+    Sec56,
+    Sec64,
+    Sec128,  // 2.13 min
+    Sec192,  // 3.20 min
+    Sec256,  // 4.27 min
+    Sec320,  // 5.33 min
+    Sec384,  // 6.40 min
+    Sec448,  // 7.47 min
+    Sec512,  // 8.53 min
+    Sec1024, // 17.07 min
+    Sec2048, // 34.13 min
+    Sec3072, // 51.20 min
+    Sec4096, // 68.27 min
+    Sec5120, // 85.33 min
+    Sec6144, // 102.40 min
+    Sec7168, // 119.47 min
+    Sec8192, // 136.53 min
+}
+
+impl Timeout {
+    fn get_period(self) -> vals::Per {
+        match self {
+            //  period count is 2**25
+            Self::Sec1024
+            | Self::Sec2048
+            | Self::Sec3072
+            | Self::Sec4096
+            | Self::Sec5120
+            | Self::Sec6144
+            | Self::Sec7168
+            | Self::Sec8192 => vals::Per::EN_25,
+            //  period count is 2**21
+            Self::Sec64
+            | Self::Sec128
+            | Self::Sec192
+            | Self::Sec256
+            | Self::Sec320
+            | Self::Sec384
+            | Self::Sec448
+            | Self::Sec512 => vals::Per::EN_21,
+            //  period count is 2**18
+            Self::Sec8 | Self::Sec16 | Self::Sec24 | Self::Sec32 | Self::Sec40 | Self::Sec48 | Self::Sec56 => {
+                vals::Per::EN_18
+            }
+            //  period count is 2**15
+            Self::Sec1 | Self::Sec2 | Self::Sec3 | Self::Sec4 | Self::Sec5 | Self::Sec6 | Self::Sec7 => {
+                vals::Per::EN_15
+            }
+            //  period count is 2**12
+            Self::MSec130
+            | Self::MSec250
+            | Self::MSec380
+            | Self::MSec500
+            | Self::MSec630
+            | Self::MSec750
+            | Self::MSec880 => vals::Per::EN_12,
+            //  period count is 2**10
+            Self::USec31250
+            | Self::USec62500
+            | Self::USec93750
+            | Self::USec125000
+            | Self::USec156250
+            | Self::USec187500
+            | Self::USec218750 => vals::Per::EN_10,
+            //  period count is 2**8
+            Self::USec7810
+            | Self::USec15630
+            | Self::USec23440
+            | Self::USec32250
+            | Self::USec39060
+            | Self::USec46880
+            | Self::USec54690 => vals::Per::EN_8,
+            //  period count is 2**6
+            Self::USec1950 | Self::USec3910 | Self::USec5860 | Self::USec9770 | Self::USec11720 | Self::USec13670 => {
+                vals::Per::EN_6
+            }
+        }
+    }
+
+    fn get_clkdiv(self) -> u8 {
+        match self {
+            //  divide by 1
+            Self::USec1950
+            | Self::USec7810
+            | Self::USec31250
+            | Self::MSec130
+            | Self::Sec1
+            | Self::Sec8
+            | Self::Sec64
+            | Self::Sec1024 => 0u8,
+            //  divide by 2
+            Self::USec3910
+            | Self::USec15630
+            | Self::USec62500
+            | Self::MSec250
+            | Self::Sec2
+            | Self::Sec16
+            | Self::Sec128
+            | Self::Sec2048 => 1u8,
+            //  divide by 3
+            Self::USec5860
+            | Self::USec23440
+            | Self::USec93750
+            | Self::MSec380
+            | Self::Sec3
+            | Self::Sec24
+            | Self::Sec192
+            | Self::Sec3072 => 2u8,
+            //  divide by 4
+            Self::USec32250
+            | Self::USec125000
+            | Self::MSec500
+            | Self::Sec4
+            | Self::Sec32
+            | Self::Sec256
+            | Self::Sec4096 => 3u8,
+            //  divide by 5
+            Self::USec9770
+            | Self::USec39060
+            | Self::USec156250
+            | Self::MSec630
+            | Self::Sec5
+            | Self::Sec40
+            | Self::Sec320
+            | Self::Sec5120 => 4u8,
+            //  divide by 6
+            Self::USec11720
+            | Self::USec46880
+            | Self::USec187500
+            | Self::MSec750
+            | Self::Sec6
+            | Self::Sec48
+            | Self::Sec384
+            | Self::Sec6144 => 5u8,
+            //  divide by 7
+            Self::USec13670
+            | Self::USec54690
+            | Self::USec218750
+            | Self::MSec880
+            | Self::Sec7
+            | Self::Sec56
+            | Self::Sec448
+            | Self::Sec7168 => 6u8,
+            //  divide by 8
+            Self::Sec512 | Self::Sec8192 => 7u8,
+        }
+    }
+}
+
+/// Timeout percentage that is treated as "too early" and generates violation.
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum ClosedWindowPercentage {
+    // window period is not used
+    Zero,
+    // 12.5% percents
+    Twelve,
+    // 18.75% percents
+    Eighteen,
+    // 25% percents
+    TwentyFive,
+    // 50% percents
+    Fifty,
+    // 75% percents
+    SeventyFive,
+    // 81.25% percents
+    EightyOne,
+    // 87.5% percents
+    EightySeven,
+}
+
+impl ClosedWindowPercentage {
+    fn get_native_size(self) -> vals::Window {
+        match self {
+            Self::Zero => vals::Window::SIZE_0,
+            Self::Twelve => vals::Window::SIZE_12,
+            Self::Eighteen => vals::Window::SIZE_18,
+            Self::TwentyFive => vals::Window::SIZE_25,
+            Self::Fifty => vals::Window::SIZE_50,
+            Self::SeventyFive => vals::Window::SIZE_75,
+            Self::EightyOne => vals::Window::SIZE_81,
+            Self::EightySeven => vals::Window::SIZE_87,
+        }
+    }
+}
+
+#[non_exhaustive]
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+/// Watchdog Config
+pub struct Config {
+    /// Watchdog timeout
+    pub timeout: Timeout,
+
+    /// closed window percentage
+    pub closed_window: ClosedWindowPercentage,
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        Self {
+            timeout: Timeout::Sec1,
+            closed_window: ClosedWindowPercentage::Zero,
+        }
+    }
+}
+
+pub struct Watchdog<'d, T: Instance> {
+    wdt: PhantomData<&'d mut T>,
+}
+
+impl<'d, T: Instance> Watchdog<'d, T> {
+    /// Watchdog initialization.
+    pub fn new(_instance: Peri<'d, T>, config: Config) -> Self {
+        // Init power for watchdog
+        T::REGS.gprcm(0).rstctl().write(|w| {
+            w.set_resetstkyclr(true);
+            w.set_resetassert(true);
+            w.set_key(vals::ResetKey::KEY);
+        });
+
+        // Enable power for watchdog
+        T::REGS.gprcm(0).pwren().write(|w| {
+            w.set_enable(true);
+            w.set_key(vals::PwrenKey::KEY);
+        });
+
+        // init delay, 16 cycles
+        cortex_m::asm::delay(16);
+
+        //init watchdog
+        T::REGS.wwdtctl0().write(|w| {
+            w.set_clkdiv(config.timeout.get_clkdiv());
+            w.set_per(config.timeout.get_period());
+            w.set_mode(vals::Mode::WINDOW);
+            w.set_window0(config.closed_window.get_native_size());
+            w.set_window1(vals::Window::SIZE_0);
+            w.set_key(vals::Wwdtctl0Key::KEY);
+        });
+
+        // Set Window0 as active window
+        T::REGS.wwdtctl1().write(|w| {
+            w.set_winsel(vals::Winsel::WIN0);
+            w.set_key(vals::Wwdtctl1Key::KEY);
+        });
+
+        critical_section::with(|_| {
+            // make sure watchdog triggers BOOTRST
+            pac::SYSCTL.systemcfg().write(|w| {
+                if T::REGS == pac::WWDT0 {
+                    w.set_wwdtlp0rstdis(false);
+                }
+
+                #[cfg(any(mspm0g110x, mspm0g150x, mspm0g151x, mspm0g310x, mspm0g350x, mspm0g351x))]
+                if T::REGS == pac::WWDT1 {
+                    w.set_wwdtlp1rstdis(false);
+                }
+            });
+        });
+
+        Watchdog { wdt: PhantomData }
+    }
+
+    /// Pet (reload, refresh) the watchdog.
+    pub fn pet(&mut self) {
+        T::REGS.wwdtcntrst().write(|w| {
+            w.set_restart(vals::WwdtcntrstRestart::RESTART);
+        });
+    }
+}
+
+pub(crate) trait SealedInstance {
+    const REGS: Regs;
+}
+
+/// WWDT instance trait
+#[allow(private_bounds)]
+pub trait Instance: SealedInstance + PeripheralType {}
+
+macro_rules! impl_wwdt_instance {
+    ($instance: ident) => {
+        impl crate::watchdog::SealedInstance for crate::peripherals::$instance {
+            const REGS: crate::pac::wwdt::Wwdt = crate::pac::$instance;
+        }
+
+        impl crate::watchdog::Instance for crate::peripherals::$instance {}
+    };
+}