Make Pwm trait method fallible

Author: eldruin

src/lib.rs

@@ -847,6 +847,9 @@ pub trait Capture {
 // reason: pre-singletons API. The `PwmPin` trait seems more useful because it models independent
 // PWM channels. Here a certain number of channels are multiplexed in a single implementer.
 pub trait Pwm {
+    /// Enumeration of `Pwm` errors
+    type Error;
+
     /// Enumeration of channels that can be used with this `Pwm` interface
     ///
     /// If your `Pwm` interface has no channels you can use the type `()`
@@ -863,25 +866,25 @@ pub trait Pwm {
     type Duty;
 
     /// Disables a PWM `channel`
-    fn disable(&mut self, channel: Self::Channel);
+    fn disable(&mut self, channel: Self::Channel) -> Result<(), Self::Error>;
 
     /// Enables a PWM `channel`
-    fn enable(&mut self, channel: Self::Channel);
+    fn enable(&mut self, channel: Self::Channel) -> Result<(), Self::Error>;
 
     /// Returns the current PWM period
-    fn get_period(&self) -> Self::Time;
+    fn get_period(&self) -> Result<Self::Time, Self::Error>;
 
     /// Returns the current duty cycle
-    fn get_duty(&self, channel: Self::Channel) -> Self::Duty;
+    fn get_duty(&self, channel: Self::Channel) -> Result<Self::Duty, Self::Error>;
 
     /// Returns the maximum duty cycle value
-    fn get_max_duty(&self) -> Self::Duty;
+    fn get_max_duty(&self) -> Result<Self::Duty, Self::Error>;
 
     /// Sets a new duty cycle
-    fn set_duty(&mut self, channel: Self::Channel, duty: Self::Duty);
+    fn set_duty(&mut self, channel: Self::Channel, duty: Self::Duty) -> Result<(), Self::Error>;
 
     /// Sets a new PWM period
-    fn set_period<P>(&mut self, period: P)
+    fn set_period<P>(&mut self, period: P) -> Result<(), Self::Error>
     where
         P: Into<Self::Time>;
 }