Merge pull request #252 from timokroeger/no-rtc-typestate

Remove `Started`/`Stopped` type state from `Rtc`

Author: jonas-schievink

examples/rtc-demo/src/main.rs

@@ -24,19 +24,19 @@ fn main() -> ! {
     let clocks = clocks.start_lfclk();
 
     // Run RTC for 1 second
-    let mut rtc = Rtc::new(p.RTC0);
+    let mut rtc = Rtc::new(p.RTC0, 0).unwrap();
     rtc.set_compare(RtcCompareReg::Compare0, 32_768).unwrap();
     rtc.enable_event(RtcInterrupt::Compare0);
 
     rprintln!("Starting RTC");
-    let rtc = rtc.enable_counter();
+    rtc.enable_counter();
 
     rprintln!("Waiting for compare match");
     while !rtc.is_event_triggered(RtcInterrupt::Compare0) {}
     rtc.reset_event(RtcInterrupt::Compare0);
 
     rprintln!("Compare match, stopping RTC");
-    let rtc = rtc.disable_counter();
+    rtc.disable_counter();
 
     rprintln!("Counter stopped at {} ticks", rtc.get_counter());
 

nrf-hal-common/src/rtc.rs

@@ -11,29 +11,9 @@ use crate::pac::{rtc0, Interrupt, NVIC, RTC0, RTC1};
 #[cfg(any(feature = "52832", feature = "52833", feature = "52840"))]
 use crate::pac::RTC2;
 
-// Zero Size Type State structs
-
-/// The RTC has been stopped.
-pub struct Stopped;
-/// The RTC has been started.
-pub struct Started;
-
 /// An opaque high level interface to an RTC peripheral.
-pub struct Rtc<T, M> {
+pub struct Rtc<T> {
     periph: T,
-    _mode: M,
-}
-
-impl<T> Rtc<T, Stopped>
-where
-    T: Instance,
-{
-    pub fn new(rtc: T) -> Self {
-        Rtc {
-            periph: rtc,
-            _mode: Stopped,
-        }
-    }
 }
 
 /// Interrupts/Events that can be generated by the RTCn peripheral.
@@ -54,30 +34,34 @@ pub enum RtcCompareReg {
     Compare3,
 }
 
-impl<T, M> Rtc<T, M>
+impl<T> Rtc<T>
 where
     T: Instance,
 {
+    /// Creates a new RTC peripheral instance with a 12 bits prescaler.
+    /// fRTC = 32_768 / (`prescaler` + 1 )
+    pub fn new(rtc: T, prescaler: u32) -> Result<Self, Error> {
+        if prescaler >= (1 << 12) {
+            return Err(Error::PrescalerOutOfRange);
+        }
+
+        unsafe { rtc.prescaler.write(|w| w.bits(prescaler)) };
+
+        Ok(Rtc { periph: rtc })
+    }
+
     /// Enable/start the Real Time Counter.
-    pub fn enable_counter(self) -> Rtc<T, Started> {
+    pub fn enable_counter(&self) {
         unsafe {
             self.periph.tasks_start.write(|w| w.bits(1));
         }
-        Rtc {
-            periph: self.periph,
-            _mode: Started,
-        }
     }
 
     /// Disable/stop the Real Time Counter.
-    pub fn disable_counter(self) -> Rtc<T, Stopped> {
+    pub fn disable_counter(&self) {
         unsafe {
             self.periph.tasks_stop.write(|w| w.bits(1));
         }
-        Rtc {
-            periph: self.periph,
-            _mode: Stopped,
-        }
     }
 
     /// Enable the generation of a hardware interrupt from a given stimulus.
@@ -234,23 +218,6 @@ pub enum Error {
     CompareOutOfRange,
 }
 
-impl<T> Rtc<T, Stopped>
-where
-    T: Instance,
-{
-    /// Set the prescaler for the RTC peripheral. 12 bits of range.
-    /// fRTC = 32_768 / (`prescaler` + 1 )
-    pub fn set_prescaler(&mut self, prescaler: u32) -> Result<(), Error> {
-        if prescaler >= (1 << 12) {
-            return Err(Error::PrescalerOutOfRange);
-        }
-
-        unsafe { self.periph.prescaler.write(|w| w.bits(prescaler)) };
-
-        Ok(())
-    }
-}
-
 /// Implemented by all RTC instances.
 pub trait Instance: Deref<Target = rtc0::RegisterBlock> {
     /// The interrupt associated with this RTC instance.