Make PwmPin methods fallible

Author: eldruin

src/lib.rs

@@ -893,26 +893,29 @@ pub trait Pwm {
 ///
 /// See `Pwm` for details
 pub trait PwmPin {
+    /// Enumeration of `PwmPin` errors
+    type Error;
+
     /// Type for the `duty` methods
     ///
     /// The implementer is free to choose a float / percentage representation
     /// (e.g. `0.0 .. 1.0`) or an integer representation (e.g. `0 .. 65535`)
     type Duty;
 
     /// Disables a PWM `channel`
-    fn disable(&mut self);
+    fn disable(&mut self) -> Result<(), Self::Error>;
 
     /// Enables a PWM `channel`
-    fn enable(&mut self);
+    fn enable(&mut self) -> Result<(), Self::Error>;
 
     /// Returns the current duty cycle
-    fn get_duty(&self) -> Self::Duty;
+    fn get_duty(&self) -> 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, duty: Self::Duty);
+    fn set_duty(&mut self, duty: Self::Duty) -> Result<(), Self::Error>;
 }
 
 /// Quadrature encoder interface