OSTimer updates (#24)

* Initialize OSTIMER0 during HAL initialization

Provide the user with a working time driver.

Signed-off-by: Felipe Balbi <[email protected]>

* Handle time_driver interrupt internally

Signed-off-by: Felipe Balbi <[email protected]>

* Gate `time-driver` impl behind a `time` flag

Also prevents creation of an `Ostimer` instance if the `time`
feature is active.

* Remove some dead code

---------

Signed-off-by: Felipe Balbi <[email protected]>
Co-authored-by: James Munns <[email protected]>

4 files changed, 81 insertions, 26 deletions

diff --git a/src/clocks/mod.rs b/src/clocks/mod.rs
index 558fb0278..a12e125c6 100644
--- a/src/clocks/mod.rs
+++ b/src/clocks/mod.rs
@@ -867,7 +867,9 @@ macro_rules! impl_cc_gate {
 /// This module contains implementations of MRCC APIs, specifically of the [`Gate`] trait,
 /// for various low level peripherals.
 pub(crate) mod gate {
-    use super::periph_helpers::{AdcConfig, LpuartConfig, NoConfig, OsTimerConfig};
+    #[cfg(not(feature = "time"))]
+    use super::periph_helpers::OsTimerConfig;
+    use super::periph_helpers::{AdcConfig, LpuartConfig, NoConfig};
     use super::*;
 
     // These peripherals have no additional upstream clocks or configuration required
@@ -888,7 +890,9 @@ pub(crate) mod gate {
 
     // These peripherals DO have meaningful configuration, and could fail if the system
     // clocks do not match their needs.
+    #[cfg(not(feature = "time"))]
     impl_cc_gate!(OSTIMER0, mrcc_glb_cc1, mrcc_glb_rst1, ostimer0, OsTimerConfig);
+
     impl_cc_gate!(LPUART2, mrcc_glb_cc0, mrcc_glb_rst0, lpuart2, LpuartConfig);
     impl_cc_gate!(ADC1, mrcc_glb_cc1, mrcc_glb_rst1, adc1, AdcConfig);
 }
diff --git a/src/config.rs b/src/config.rs
index 0939c11f1..9c0d47ecb 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -5,6 +5,7 @@ use crate::interrupt::Priority;
 
 #[non_exhaustive]
 pub struct Config {
+    #[cfg(feature = "time")]
     pub time_interrupt_priority: Priority,
     pub rtc_interrupt_priority: Priority,
     pub adc_interrupt_priority: Priority,
@@ -14,6 +15,7 @@ pub struct Config {
 impl Default for Config {
     fn default() -> Self {
         Self {
+            #[cfg(feature = "time")]
             time_interrupt_priority: Priority::from(0),
             rtc_interrupt_priority: Priority::from(0),
             adc_interrupt_priority: Priority::from(0),
diff --git a/src/lib.rs b/src/lib.rs
index c885ecc50..e93ff61a6 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -14,6 +14,9 @@ pub mod lpuart;
 pub mod ostimer;
 pub mod rtc;
 
+#[cfg(feature = "rt")]
+pub use crate::pac::NVIC_PRIO_BITS;
+
 #[rustfmt::skip]
 embassy_hal_internal::peripherals!(
     ADC0,
@@ -83,6 +86,8 @@ embassy_hal_internal::peripherals!(
     MBC0,
     MRCC0,
     OPAMP0,
+
+    #[cfg(not(feature = "time"))]
     OSTIMER0,
 
     P0_0,
@@ -335,7 +340,6 @@ pub use interrupt::InterruptExt;
 pub use mcxa_pac as pac;
 #[cfg(not(feature = "unstable-pac"))]
 pub(crate) use mcxa_pac as pac;
-pub use ostimer::Ostimer0 as Ostimer0Token;
 pub use rtc::Rtc0 as Rtc0Token;
 
 /// Initialize HAL with configuration (mirrors embassy-imxrt style). Minimal: just take peripherals.
@@ -343,6 +347,7 @@ pub use rtc::Rtc0 as Rtc0Token;
 pub fn init(cfg: crate::config::Config) -> Peripherals {
     let peripherals = Peripherals::take();
     // Apply user-configured priority early; enabling is left to examples/apps
+    #[cfg(feature = "time")]
     crate::interrupt::OS_EVENT.set_priority(cfg.time_interrupt_priority);
     // Apply user-configured priority early; enabling is left to examples/apps
     crate::interrupt::RTC.set_priority(cfg.rtc_interrupt_priority);
@@ -352,6 +357,10 @@ pub fn init(cfg: crate::config::Config) -> Peripherals {
     // Configure clocks
     crate::clocks::init(cfg.clock_cfg).unwrap();
 
+    // Initialize embassy-time global driver backed by OSTIMER0
+    #[cfg(feature = "time")]
+    crate::ostimer::time_driver::init(crate::config::Config::default().time_interrupt_priority, 1_000_000);
+
     // Enable GPIO clocks
     unsafe {
         _ = crate::clocks::enable_and_reset::<crate::peripherals::PORT0>(&crate::clocks::periph_helpers::NoConfig);
diff --git a/src/ostimer.rs b/src/ostimer.rs
index cd5451b53..c51812e3d 100644
--- a/src/ostimer.rs
+++ b/src/ostimer.rs
@@ -35,7 +35,6 @@ use crate::clocks::periph_helpers::{OsTimerConfig, OstimerClockSel};
 use crate::clocks::{assert_reset, enable_and_reset, is_reset_released, release_reset, Gate, PoweredClock};
 use crate::interrupt::InterruptExt;
 use crate::pac;
-use crate::peripherals::OSTIMER0;
 
 // PAC defines the shared RegisterBlock under `ostimer0`.
 type Regs = pac::ostimer0::RegisterBlock;
@@ -283,15 +282,15 @@ impl<'d, I: Instance> Ostimer<'d, I> {
                 .write(|w| w.ostimer_intrflag().clear_bit_by_one().ostimer_intena().clear_bit());
 
             unsafe {
-                assert_reset::<OSTIMER0>();
+                assert_reset::<I>();
 
                 for _ in 0..RESET_STABILIZE_SPINS {
                     cortex_m::asm::nop();
                 }
 
-                release_reset::<OSTIMER0>();
+                release_reset::<I>();
 
-                while !is_reset_released::<OSTIMER0>() {
+                while !is_reset_released::<I>() {
                     cortex_m::asm::nop();
                 }
             }
@@ -490,9 +489,7 @@ pub trait Instance: Gate<MrccPeriphConfig = OsTimerConfig> + PeripheralType {
     fn ptr() -> *const Regs;
 }
 
-// Token for OSTIMER0 provided by embassy-hal-internal peripherals macro.
-pub type Ostimer0 = crate::peripherals::OSTIMER0;
-
+#[cfg(not(feature = "time"))]
 impl Instance for crate::peripherals::OSTIMER0 {
     #[inline(always)]
     fn ptr() -> *const Regs {
@@ -500,14 +497,6 @@ impl Instance for crate::peripherals::OSTIMER0 {
     }
 }
 
-// Also implement Instance for the Peri wrapper type
-// impl Instance for embassy_hal_internal::Peri<'_, crate::peripherals::OSTIMER0> {
-//     #[inline(always)]
-//     fn ptr() -> *const Regs {
-//         pac::Ostimer0::ptr()
-//     }
-// }
-
 #[inline(always)]
 fn bin_to_gray(x: u64) -> u64 {
     x ^ (x >> 1)
@@ -523,6 +512,7 @@ fn gray_to_bin(gray: u64) -> u64 {
     bin
 }
 
+#[cfg(feature = "time")]
 pub mod time_driver {
     use core::sync::atomic::Ordering;
     use core::task::Waker;
@@ -537,7 +527,55 @@ pub mod time_driver {
     use crate::clocks::periph_helpers::{OsTimerConfig, OstimerClockSel};
     use crate::clocks::{enable_and_reset, PoweredClock};
     use crate::pac;
-    use crate::peripherals::OSTIMER0;
+
+    #[allow(non_camel_case_types)]
+    pub(crate) struct _OSTIMER0_TIME_DRIVER {
+        _x: (),
+    }
+
+    // #[cfg(feature = "time")]
+    // impl_cc_gate!(_OSTIMER0_TIME_DRIVER, mrcc_glb_cc1, mrcc_glb_rst1, ostimer0, OsTimerConfig);
+
+    impl crate::clocks::Gate for _OSTIMER0_TIME_DRIVER {
+        type MrccPeriphConfig = crate::clocks::periph_helpers::OsTimerConfig;
+
+        #[inline]
+        unsafe fn enable_clock() {
+            let mrcc = unsafe { pac::Mrcc0::steal() };
+            mrcc.mrcc_glb_cc1().modify(|_, w| w.ostimer0().enabled());
+        }
+
+        #[inline]
+        unsafe fn disable_clock() {
+            let mrcc = unsafe { pac::Mrcc0::steal() };
+            mrcc.mrcc_glb_cc1().modify(|_r, w| w.ostimer0().disabled());
+        }
+
+        #[inline]
+        fn is_clock_enabled() -> bool {
+            let mrcc = unsafe { pac::Mrcc0::steal() };
+            mrcc.mrcc_glb_cc1().read().ostimer0().is_enabled()
+        }
+
+        #[inline]
+        unsafe fn release_reset() {
+            let mrcc = unsafe { pac::Mrcc0::steal() };
+            mrcc.mrcc_glb_rst1().modify(|_, w| w.ostimer0().enabled());
+        }
+
+        #[inline]
+        unsafe fn assert_reset() {
+            let mrcc = unsafe { pac::Mrcc0::steal() };
+            mrcc.mrcc_glb_rst1().modify(|_, w| w.ostimer0().disabled());
+        }
+
+        #[inline]
+        fn is_reset_released() -> bool {
+            let mrcc = unsafe { pac::Mrcc0::steal() };
+            mrcc.mrcc_glb_rst1().read().ostimer0().is_enabled()
+        }
+    }
+
     pub struct Driver;
     static TIMER_WAKER: AtomicWaker = AtomicWaker::new();
 
@@ -625,7 +663,7 @@ pub mod time_driver {
     /// The embassy_time_driver macro handles driver registration automatically.
     pub fn init(priority: crate::interrupt::Priority, frequency_hz: u64) {
         let _clock_freq = unsafe {
-            enable_and_reset::<OSTIMER0>(&OsTimerConfig {
+            enable_and_reset::<_OSTIMER0_TIME_DRIVER>(&OsTimerConfig {
                 power: PoweredClock::AlwaysEnabled,
                 source: OstimerClockSel::Clk1M,
             })
@@ -694,12 +732,14 @@ pub mod time_driver {
             }
         });
     }
+}
 
-    /// Type-level handler to be used with bind_interrupts! for OS_EVENT.
-    pub struct OsEventHandler;
-    impl crate::interrupt::typelevel::Handler<crate::interrupt::typelevel::OS_EVENT> for OsEventHandler {
-        unsafe fn on_interrupt() {
-            on_interrupt();
-        }
-    }
+#[cfg(feature = "time")]
+use crate::pac::interrupt;
+
+#[cfg(feature = "time")]
+#[allow(non_snake_case)]
+#[interrupt]
+fn OS_EVENT() {
+    time_driver::on_interrupt()
 }