Pwm remap: another try (#147)

* implement remap for Timers when pwm is used

move Remap to timer.rs, add gpio::Mode

Author: burrbull

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 
+- Added `Mode` marker trait for `gpio` pins that correspondent to pin mode.
 - RCC `Bus` trait + private `Enable` and `Reset` traits
 - Added `micros_since` and `reset` methods to timer
 - Added `select_frequency` method to RTC
@@ -19,6 +20,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Breaking changes
 
+- Implement more pin combinations for PWM configuration, added PWM for TIM1 (API for custom PWM pins was removed as it's no more needed)
 - Bump `stm32f1` dependency (`0.9.0`)
 - `void::Void` replaced with `Infallible` where it is possible
 - Change timer/pwm init API

examples/pwm_custom.rs

@@ -8,38 +8,13 @@ use panic_halt as _;
 
 use cortex_m::asm;
 use stm32f1xx_hal::{
-    gpio::gpiob::{PB4, PB5},
-    gpio::{Alternate, PushPull},
-    pac::{self,TIM3},
+    pac,
     prelude::*,
-    pwm::{Pins, Pwm, C1, C2},
     timer::Timer,
 };
 
 use cortex_m_rt::entry;
 
-// Using PB5 channel for TIM3 PWM output 
-// struct MyChannels(PB5<Alternate<PushPull>>);
-// impl Pins<TIM3>  for MyChannels {
-//     const REMAP: u8 = 0b10;
-//     const C1: bool = false;
-//     const C2: bool = true;
-//     const C3: bool = false;
-//     const C4: bool = false;
-//     type Channels = Pwm<TIM3, C2>;
-// }
-
-// Using PB4 and PB5 channels for TIM3 PWM output
-struct MyChannels(PB4<Alternate<PushPull>>, PB5<Alternate<PushPull>>);
-impl Pins<TIM3> for MyChannels {
-    const REMAP: u8 = 0b10;
-    const C1: bool = true;
-    const C2: bool = true;
-    const C3: bool = false;
-    const C4: bool = false;
-    type Channels = (Pwm<TIM3, C1>, Pwm<TIM3, C2>);
-}
-
 #[entry]
 fn main() -> ! {
     let p = pac::Peripherals::take().unwrap();
@@ -59,11 +34,7 @@ fn main() -> ! {
     let p1 = gpiob.pb5.into_alternate_push_pull(&mut gpiob.crl);
 
     let mut pwm = Timer::tim3(p.TIM3, &clocks, &mut rcc.apb1)
-        .pwm(
-            MyChannels(p0, p1),
-            &mut afio.mapr,
-            1.khz(),
-        );
+        .pwm((p0, p1), &mut afio.mapr, 1.khz());
 
     let max = pwm.0.get_max_duty();
 

src/gpio.rs

@@ -27,6 +27,10 @@ pub trait GpioExt {
     fn split(self, apb2: &mut APB2) -> Self::Parts;
 }
 
+
+/// Marker trait for pin mode detection.
+pub trait Mode<MODE> {}
+
 /// Marker trait for active states.
 pub trait Active {}
 
@@ -95,7 +99,8 @@ macro_rules! gpio {
                 State,
                 Active,
                 Debugger,
-                Pxx
+                Pxx,
+                Mode,
             };
 
             /// GPIO parts
@@ -216,13 +221,17 @@ macro_rules! gpio {
             pub type $PXx<MODE> = Pxx<MODE>;
 
 
+            impl<MODE> Mode<MODE> for Generic<MODE> {}
+
 
             $(
                 /// Pin
                 pub struct $PXi<MODE> {
                     _mode: PhantomData<MODE>,
                 }
 
+                impl<MODE> Mode<MODE> for $PXi<MODE> {}
+
                 impl $PXi<Debugger> {
                     /// Put the pin in an active state. The caller
                     /// must enforce that the pin is really in this