[ESP32-C6-LP] Add input support for IO driver, implement more embedded-hal output traits (#720)

* Add input support for IO driver, implement more `embedded-hal` output traits

* Update CHANGELOG

CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Add the `esp32c6-lp-hal` package (#714)
 - Add GPIO (output) and delay functionality to `esp32c6-lp-hal` (#715)
 - Implement RTCIO pullup, pulldown and hold control for Xtensa MCUs (#684)
+- Add GPIO input support and implement additional `embedded-hal` output traits for the C6's LP core [#720]
 
 ### Changed
 

esp32c6-lp-hal/examples/blinky.rs

@@ -4,7 +4,7 @@
 #![no_std]
 #![no_main]
 
-use esp32c6_lp_hal::{gpio::Io, prelude::*};
+use esp32c6_lp_hal::{delay::Delay, gpio::IO, prelude::*};
 use panic_halt as _;
 
 #[entry]
@@ -13,11 +13,11 @@ fn main() -> ! {
 
     let peripherals = esp32c6_lp::Peripherals::take().unwrap();
 
-    let io = Io::new(peripherals.LP_IO);
+    let io = IO::new(peripherals.LP_IO);
     let mut gpio1 = io.gpio1.into_output();
 
     let ptr = 0x5000_2000 as *mut u32;
-    let mut delay = delay::Delay::new();
+    let mut delay = Delay::new();
 
     loop {
         i = i.wrapping_add(1u32);

esp32c6-lp-hal/src/gpio.rs

@@ -1,23 +1,14 @@
-//! LP-GPIO driver
+//! Low-power GPIO driver
 //!
 //! It's assumed that GPIOs are already configured correctly by the HP core.
 
 use core::{convert::Infallible, marker::PhantomData};
 
-use embedded_hal::digital::v2::OutputPin;
-
-pub struct Unknown {}
-
-pub struct Output;
+use esp32c6_lp::LP_IO;
 
 #[non_exhaustive]
-pub struct GpioPin<const PIN: u8, MODE> {
-    phantom: PhantomData<MODE>,
-}
-
-#[non_exhaustive]
-pub struct Io {
-    _peripheral: esp32c6_lp::LP_IO,
+pub struct IO {
+    _peripheral: LP_IO,
 
     pub gpio0: GpioPin<0, Unknown>,
     pub gpio1: GpioPin<1, Unknown>,
@@ -29,10 +20,11 @@ pub struct Io {
     pub gpio7: GpioPin<7, Unknown>,
 }
 
-impl Io {
-    pub fn new(peripheral: esp32c6_lp::LP_IO) -> Self {
+impl IO {
+    pub fn new(peripheral: LP_IO) -> Self {
         Self {
             _peripheral: peripheral,
+
             gpio0: GpioPin::new(),
             gpio1: GpioPin::new(),
             gpio2: GpioPin::new(),
@@ -45,13 +37,30 @@ impl Io {
     }
 }
 
+pub struct Unknown {}
+
+pub struct Input;
+
+pub struct Output;
+
+#[non_exhaustive]
+pub struct GpioPin<const PIN: u8, MODE> {
+    phantom: PhantomData<MODE>,
+}
+
 impl<const PIN: u8, MODE> GpioPin<PIN, MODE> {
     fn new() -> Self {
         GpioPin {
-            phantom: PhantomData::default(),
+            phantom: PhantomData,
         }
     }
 
+    /// Assuming the GPIO is already configured by the HP core this makes the
+    /// GPIO into an input pin.
+    pub fn into_input(self) -> GpioPin<PIN, Input> {
+        GpioPin::new()
+    }
+
     /// Assuming the GPIO is already configured by the HP core this makes the
     /// GPIO into an output pin.
     pub fn into_output(self) -> GpioPin<PIN, Output> {
@@ -59,22 +68,64 @@ impl<const PIN: u8, MODE> GpioPin<PIN, MODE> {
     }
 }
 
-impl<const PIN: u8> OutputPin for GpioPin<PIN, Output> {
+impl<const PIN: u8> GpioPin<PIN, Input> {
+    fn input_state(&self) -> bool {
+        unsafe { &*LP_IO::PTR }.in_.read().bits() >> PIN & 0x1 != 0
+    }
+}
+
+impl<const PIN: u8> GpioPin<PIN, Output> {
+    fn output_state(&self) -> bool {
+        unsafe { &*LP_IO::PTR }.out.read().bits() >> PIN & 0x1 != 0
+    }
+
+    fn set_output_low(&mut self) {
+        unsafe { &*LP_IO::PTR }
+            .out_w1tc
+            .write(|w| w.out_data_w1tc().variant(1 << PIN));
+    }
+
+    fn set_output_high(&mut self) {
+        unsafe { &*LP_IO::PTR }
+            .out_w1ts
+            .write(|w| w.out_data_w1ts().variant(1 << PIN));
+    }
+}
+
+impl<const PIN: u8> embedded_hal::digital::v2::InputPin for GpioPin<PIN, Input> {
+    type Error = Infallible;
+
+    fn is_high(&self) -> Result<bool, Self::Error> {
+        Ok(self.input_state())
+    }
+
+    fn is_low(&self) -> Result<bool, Self::Error> {
+        Ok(!self.is_high()?)
+    }
+}
+
+impl<const PIN: u8> embedded_hal::digital::v2::OutputPin for GpioPin<PIN, Output> {
     type Error = Infallible;
 
     fn set_low(&mut self) -> Result<(), Self::Error> {
-        let lp_gpio = unsafe { &*esp32c6_lp::LP_IO::PTR };
-        lp_gpio
-            .out_w1tc
-            .write(|w| w.out_data_w1tc().variant(1 << PIN));
+        self.set_output_low();
         Ok(())
     }
 
     fn set_high(&mut self) -> Result<(), Self::Error> {
-        let lp_gpio = unsafe { &*esp32c6_lp::LP_IO::PTR };
-        lp_gpio
-            .out_w1ts
-            .write(|w| w.out_data_w1ts().variant(1 << PIN));
+        self.set_output_high();
         Ok(())
     }
 }
+
+impl<const PIN: u8> embedded_hal::digital::v2::StatefulOutputPin for GpioPin<PIN, Output> {
+    fn is_set_high(&self) -> Result<bool, Self::Error> {
+        Ok(self.output_state())
+    }
+
+    fn is_set_low(&self) -> Result<bool, Self::Error> {
+        Ok(!self.is_set_high()?)
+    }
+}
+
+impl<const PIN: u8> embedded_hal::digital::v2::toggleable::Default for GpioPin<PIN, Output> {}

esp32c6-lp-hal/src/prelude.rs

@@ -3,7 +3,13 @@
 //! Re-exports all traits required for interacting with the various peripheral
 //! drivers implemented in this crate.
 
-pub use embedded_hal::{digital::v2::OutputPin, prelude::*};
+pub use embedded_hal::{
+    digital::v2::{
+        InputPin as _embedded_hal_digital_vs_InputPin,
+        OutputPin as _embedded_hal_digital_vs_OutputPin,
+        StatefulOutputPin as _embedded_hal_digital_vs_StatefulOutputPin,
+        ToggleableOutputPin as _embedded_hal_digital_vs_ToggleableOutputPin,
+    },
+    prelude::*,
+};
 pub use riscv_rt_macros::entry;
-
-pub use crate::delay;