Pull resistors

Author: burrbull

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Changed
 
 - CI updates + cache
+- Remove pull resistor from `Input` mode, use `Pull` enum instead
 - Move pin mode at the end of generics, add defaults for modes,
   bump MSRV to 1.59 [#418]
 - Move hd44780-driver to dev-dependencies

examples/analog-stopwatch-with-spi-ssd1306.rs

@@ -11,7 +11,7 @@ use panic_semihosting as _;
 use stm32f4xx_hal as hal;
 
 use crate::hal::{
-    gpio::{Edge, Input, PullDown, PA0},
+    gpio::{Edge, Input, PA0},
     interrupt, pac,
     prelude::*,
     rcc::{Clocks, Rcc},
@@ -45,7 +45,7 @@ static ELAPSED_MS: Mutex<Cell<u32>> = Mutex::new(Cell::new(0u32));
 static ELAPSED_RESET_MS: Mutex<Cell<u32>> = Mutex::new(Cell::new(0u32));
 static TIMER_TIM2: Mutex<RefCell<Option<CounterUs<pac::TIM2>>>> = Mutex::new(RefCell::new(None));
 static STATE: Mutex<Cell<StopwatchState>> = Mutex::new(Cell::new(StopwatchState::Ready));
-static BUTTON: Mutex<RefCell<Option<PA0<Input<PullDown>>>>> = Mutex::new(RefCell::new(None));
+static BUTTON: Mutex<RefCell<Option<PA0<Input>>>> = Mutex::new(RefCell::new(None));
 
 /// The center of the clock face
 const CENTER: Point = Point::new(64, 40);

examples/rtic.rs

@@ -8,7 +8,7 @@ use panic_halt as _;
 #[rtic::app(device = stm32f4xx_hal::pac)]
 mod app {
     use stm32f4xx_hal::{
-        gpio::{Edge, Input, Output, PullUp, PushPull, PA0, PC13},
+        gpio::{Edge, Input, Output, PushPull, PA0, PC13},
         prelude::*,
     };
 
@@ -17,7 +17,7 @@ mod app {
 
     #[local]
     struct Local {
-        button: PA0<Input<PullUp>>,
+        button: PA0<Input>,
         led: PC13<Output<PushPull>>,
     }
 

examples/stopwatch-with-ssd1306-and-interrupts.rs

@@ -22,7 +22,7 @@ use panic_semihosting as _; // logs messages to the host stderr; requires a debu
 use stm32f4xx_hal as hal;
 
 use crate::hal::{
-    gpio::{Edge, Input, PullUp, PC13},
+    gpio::{Edge, Input, PC13},
     i2c::I2c,
     interrupt, pac,
     prelude::*,
@@ -50,7 +50,7 @@ use ssd1306::{prelude::*, I2CDisplayInterface, Ssd1306};
 static ELAPSED_MS: Mutex<Cell<u32>> = Mutex::new(Cell::new(0u32));
 static TIMER_TIM2: Mutex<RefCell<Option<CounterUs<pac::TIM2>>>> = Mutex::new(RefCell::new(None));
 static STATE: Mutex<Cell<StopwatchState>> = Mutex::new(Cell::new(StopwatchState::Ready));
-static BUTTON: Mutex<RefCell<Option<PC13<Input<PullUp>>>>> = Mutex::new(RefCell::new(None));
+static BUTTON: Mutex<RefCell<Option<PC13<Input>>>> = Mutex::new(RefCell::new(None));
 
 #[derive(Clone, Copy)]
 enum StopwatchState {

src/gpio.rs

@@ -102,18 +102,19 @@ pub trait PinExt {
 pub struct Alternate<const A: u8, Otype = PushPull>(PhantomData<Otype>);
 
 /// Input mode (type state)
-pub struct Input<MODE = Floating> {
-    _mode: PhantomData<MODE>,
-}
-
-/// Floating input (type state)
-pub struct Floating;
-
-/// Pulled down input (type state)
-pub struct PullDown;
+pub struct Input;
 
-/// Pulled up input (type state)
-pub struct PullUp;
+/// Pull setting for an input.
+#[derive(Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum Pull {
+    /// Floating
+    None = 0,
+    /// Pulled up
+    Up = 1,
+    /// Pulled down
+    Down = 2,
+}
 
 /// Open drain input or output (type state)
 pub struct OpenDrain;
@@ -131,6 +132,10 @@ pub struct Analog;
 
 pub type Debugger = Alternate<0, PushPull>;
 
+impl sealed::Active for Input {}
+impl<Otype> sealed::Active for Output<Otype> {}
+impl<const A: u8, Otype> sealed::Active for Alternate<A, Otype> {}
+
 /// GPIO Pin speed selection
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
@@ -152,11 +157,13 @@ pub enum Edge {
 mod sealed {
     /// Marker trait that show if `ExtiPin` can be implemented
     pub trait Interruptable {}
+    /// Marker trait for active pin modes
+    pub trait Active {}
 }
 
 use sealed::Interruptable;
 impl<MODE> Interruptable for Output<MODE> {}
-impl<MODE> Interruptable for Input<MODE> {}
+impl Interruptable for Input {}
 
 /// External Interrupt Pin
 pub trait ExtiPin {
@@ -262,7 +269,7 @@ where
 /// - `MODE` is one of the pin modes (see [Modes](crate::gpio#modes) section).
 /// - `P` is port name: `A` for GPIOA, `B` for GPIOB, etc.
 /// - `N` is pin number: from `0` to `15`.
-pub struct Pin<const P: char, const N: u8, MODE = Input<Floating>> {
+pub struct Pin<const P: char, const N: u8, MODE = Input> {
     _mode: PhantomData<MODE>,
 }
 impl<const P: char, const N: u8, MODE> Pin<P, N, MODE> {
@@ -317,34 +324,6 @@ impl<const P: char, const N: u8, MODE> Pin<P, N, Output<MODE>> {
     }
 }
 
-impl<const P: char, const N: u8> Pin<P, N, Output<OpenDrain>> {
-    /// Enables / disables the internal pull up
-    pub fn internal_pull_up(self, on: bool) -> Self {
-        let offset = 2 * { N };
-        let value = if on { 0b01 } else { 0b00 };
-        unsafe {
-            (*Gpio::<P>::ptr())
-                .pupdr
-                .modify(|r, w| w.bits((r.bits() & !(0b11 << offset)) | (value << offset)))
-        };
-
-        self
-    }
-
-    /// Enables / disables the internal pull down
-    pub fn internal_pull_down(self, on: bool) -> Self {
-        let offset = 2 * { N };
-        let value = if on { 0b10 } else { 0b00 };
-        unsafe {
-            (*Gpio::<P>::ptr())
-                .pupdr
-                .modify(|r, w| w.bits((r.bits() & !(0b11 << offset)) | (value << offset)))
-        };
-
-        self
-    }
-}
-
 impl<const P: char, const N: u8, const A: u8> Pin<P, N, Alternate<A, PushPull>> {
     /// Set pin speed
     pub fn set_speed(self, speed: Speed) -> Self {
@@ -358,11 +337,13 @@ impl<const P: char, const N: u8, const A: u8> Pin<P, N, Alternate<A, PushPull>>
 
         self
     }
+}
 
-    /// Enables / disables the internal pull up
-    pub fn internal_pull_up(self, on: bool) -> Self {
+impl<const P: char, const N: u8, MODE> Pin<P, N, MODE> {
+    /// Set the internal pull-up and pull-down resistor
+    fn _internal_resistor(self, resistor: Pull) -> Self {
         let offset = 2 * { N };
-        let value = if on { 0b01 } else { 0b00 };
+        let value = resistor as u32;
         unsafe {
             (*Gpio::<P>::ptr())
                 .pupdr
@@ -371,32 +352,33 @@ impl<const P: char, const N: u8, const A: u8> Pin<P, N, Alternate<A, PushPull>>
 
         self
     }
+}
 
-    /// Enables / disables the internal pull down
-    pub fn internal_pull_down(self, on: bool) -> Self {
-        let offset = 2 * { N };
-        let value = if on { 0b10 } else { 0b00 };
-        unsafe {
-            (*Gpio::<P>::ptr())
-                .pupdr
-                .modify(|r, w| w.bits((r.bits() & !(0b11 << offset)) | (value << offset)))
-        };
-
-        self
+impl<const P: char, const N: u8, MODE> Pin<P, N, MODE>
+where
+    MODE: sealed::Active,
+{
+    /// Set the internal pull-up and pull-down resistor
+    pub fn internal_resistor(self, resistor: Pull) -> Self {
+        self._internal_resistor(resistor)
     }
-}
 
-impl<const P: char, const N: u8, const A: u8> Pin<P, N, Alternate<A, PushPull>> {
-    /// Turns pin alternate configuration pin into open drain
-    pub fn set_open_drain(self) -> Pin<P, N, Alternate<A, OpenDrain>> {
-        let offset = { N };
-        unsafe {
-            (*Gpio::<P>::ptr())
-                .otyper
-                .modify(|r, w| w.bits(r.bits() | (1 << offset)))
-        };
+    /// Enables / disables the internal pull up
+    pub fn internal_pull_up(self, on: bool) -> Self {
+        if on {
+            self.internal_resistor(Pull::Up)
+        } else {
+            self.internal_resistor(Pull::None)
+        }
+    }
 
-        Pin::new()
+    /// Enables / disables the internal pull down
+    pub fn internal_pull_down(self, on: bool) -> Self {
+        if on {
+            self.internal_resistor(Pull::Down)
+        } else {
+            self.internal_resistor(Pull::None)
+        }
     }
 }
 
@@ -512,7 +494,7 @@ impl<const P: char, const N: u8> Pin<P, N, Output<OpenDrain>> {
     }
 }
 
-impl<const P: char, const N: u8, MODE> Pin<P, N, Input<MODE>> {
+impl<const P: char, const N: u8> Pin<P, N, Input> {
     #[inline(always)]
     pub fn is_high(&self) -> bool {
         !self.is_low()
@@ -533,7 +515,7 @@ macro_rules! gpio {
             use crate::pac::{$GPIOX, RCC};
             use crate::rcc::{Enable, Reset};
             use super::{
-                Floating, Input,
+                Input,
             };
 
             /// GPIO parts
@@ -567,7 +549,7 @@ macro_rules! gpio {
             pub type $PXn<MODE> = super::PEPin<$port_id, MODE>;
 
             $(
-                pub type $PXi<MODE = Input<Floating>> = super::Pin<$port_id, $i, MODE>;
+                pub type $PXi<MODE = Input> = super::Pin<$port_id, $i, MODE>;
             )+
 
         }