1 files changed, 361 insertions, 0 deletions

diff --git a/embassy-nxp/src/gpio.rs b/embassy-nxp/src/gpio.rs
new file mode 100644
index 000000000..d5d04ee69
--- /dev/null
+++ b/embassy-nxp/src/gpio.rs
@@ -0,0 +1,361 @@
+use embassy_hal_internal::impl_peripheral;
+
+use crate::pac_utils::*;
+use crate::{peripherals, Peripheral, PeripheralRef};
+
+pub(crate) fn init() {
+    // Enable clocks for GPIO, PINT, and IOCON
+    syscon_reg()
+        .ahbclkctrl0
+        .modify(|_, w| w.gpio0().enable().gpio1().enable().mux().enable().iocon().enable());
+}
+
+/// The GPIO pin level for pins set on "Digital" mode.
+#[derive(Debug, Eq, PartialEq, Clone, Copy)]
+pub enum Level {
+    /// Logical low. Corresponds to 0V.
+    Low,
+    /// Logical high. Corresponds to VDD.
+    High,
+}
+
+/// Pull setting for a GPIO input set on "Digital" mode.
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+pub enum Pull {
+    /// No pull.
+    None,
+    /// Internal pull-up resistor.
+    Up,
+    /// Internal pull-down resistor.
+    Down,
+}
+
+/// The LPC55 boards have two GPIO banks, each with 32 pins. This enum represents the two banks.
+#[derive(Debug, Eq, PartialEq, Clone, Copy)]
+pub enum Bank {
+    Bank0 = 0,
+    Bank1 = 1,
+}
+
+/// GPIO output driver. Internally, this is a specialized [Flex] pin.
+pub struct Output<'d> {
+    pub(crate) pin: Flex<'d>,
+}
+
+impl<'d> Output<'d> {
+    /// Create GPIO output driver for a [Pin] with the provided [initial output](Level).
+    #[inline]
+    pub fn new(pin: impl Peripheral<P = impl Pin> + 'd, initial_output: Level) -> Self {
+        let mut pin = Flex::new(pin);
+        pin.set_as_output();
+        let mut result = Self { pin };
+
+        match initial_output {
+            Level::High => result.set_high(),
+            Level::Low => result.set_low(),
+        };
+
+        result
+    }
+
+    pub fn set_high(&mut self) {
+        gpio_reg().set[self.pin.pin_bank() as usize].write(|w| unsafe { w.bits(self.pin.bit()) })
+    }
+
+    pub fn set_low(&mut self) {
+        gpio_reg().clr[self.pin.pin_bank() as usize].write(|w| unsafe { w.bits(self.pin.bit()) })
+    }
+
+    pub fn toggle(&mut self) {
+        gpio_reg().not[self.pin.pin_bank() as usize].write(|w| unsafe { w.bits(self.pin.bit()) })
+    }
+
+    /// Get the current output level of the pin. Note that the value returned by this function is
+    /// the voltage level reported by the pin, not the value set by the output driver.
+    pub fn level(&self) -> Level {
+        let bits = gpio_reg().pin[self.pin.pin_bank() as usize].read().bits();
+        if bits & self.pin.bit() != 0 {
+            Level::High
+        } else {
+            Level::Low
+        }
+    }
+}
+
+/// GPIO input driver. Internally, this is a specialized [Flex] pin.
+pub struct Input<'d> {
+    pub(crate) pin: Flex<'d>,
+}
+
+impl<'d> Input<'d> {
+    /// Create GPIO output driver for a [Pin] with the provided [Pull].
+    #[inline]
+    pub fn new(pin: impl Peripheral<P = impl Pin> + 'd, pull: Pull) -> Self {
+        let mut pin = Flex::new(pin);
+        pin.set_as_input();
+        let mut result = Self { pin };
+        result.set_pull(pull);
+
+        result
+    }
+
+    /// Set the pull configuration for the pin. To disable the pull, use [Pull::None].
+    pub fn set_pull(&mut self, pull: Pull) {
+        match_iocon!(register, iocon_reg(), self.pin.pin_bank(), self.pin.pin_number(), {
+            register.modify(|_, w| match pull {
+                Pull::None => w.mode().inactive(),
+                Pull::Up => w.mode().pull_up(),
+                Pull::Down => w.mode().pull_down(),
+            });
+        });
+    }
+
+    /// Get the current input level of the pin.
+    pub fn read(&self) -> Level {
+        let bits = gpio_reg().pin[self.pin.pin_bank() as usize].read().bits();
+        if bits & self.pin.bit() != 0 {
+            Level::High
+        } else {
+            Level::Low
+        }
+    }
+}
+
+/// A flexible GPIO (digital mode) pin whose mode is not yet determined. Under the hood, this is a
+/// reference to a type-erased pin called ["AnyPin"](AnyPin).
+pub struct Flex<'d> {
+    pub(crate) pin: PeripheralRef<'d, AnyPin>,
+}
+
+impl<'d> Flex<'d> {
+    /// Wrap the pin in a `Flex`.
+    ///
+    /// Note: you cannot assume that the pin will be in Digital mode after this call.
+    #[inline]
+    pub fn new(pin: impl Peripheral<P = impl Pin> + 'd) -> Self {
+        Self {
+            pin: pin.into_ref().map_into(),
+        }
+    }
+
+    /// Get the bank of this pin. See also [Bank].
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use embassy_nxp::gpio::{Bank, Flex};
+    ///
+    /// let p = embassy_nxp::init(Default::default());
+    /// let pin = Flex::new(p.PIO1_15);
+    ///
+    /// assert_eq!(pin.pin_bank(), Bank::Bank1);
+    /// ```
+    pub fn pin_bank(&self) -> Bank {
+        self.pin.pin_bank()
+    }
+
+    /// Get the number of this pin within its bank. See also [Bank].
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use embassy_nxp::gpio::Flex;
+    ///
+    /// let p = embassy_nxp::init(Default::default());
+    /// let pin = Flex::new(p.PIO1_15);
+    ///
+    /// assert_eq!(pin.pin_number(), 15 as u8);
+    /// ```
+    pub fn pin_number(&self) -> u8 {
+        self.pin.pin_number()
+    }
+
+    /// Get the bit mask for this pin. Useful for setting or clearing bits in a register. Note:
+    /// PIOx_0 is bit 0, PIOx_1 is bit 1, etc.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use embassy_nxp::gpio::Flex;
+    ///
+    /// let p = embassy_nxp::init(Default::default());
+    /// let pin = Flex::new(p.PIO1_3);
+    ///
+    /// assert_eq!(pin.bit(), 0b0000_1000);
+    /// ```
+    pub fn bit(&self) -> u32 {
+        1 << self.pin.pin_number()
+    }
+
+    /// Set the pin to digital mode. This is required for using a pin as a GPIO pin. The default
+    /// setting for pins is (usually) non-digital.
+    fn set_as_digital(&mut self) {
+        match_iocon!(register, iocon_reg(), self.pin_bank(), self.pin_number(), {
+            register.modify(|_, w| w.digimode().digital());
+        });
+    }
+
+    /// Set the pin in output mode. This implies setting the pin to digital mode, which this
+    /// function handles itself.
+    pub fn set_as_output(&mut self) {
+        self.set_as_digital();
+        gpio_reg().dirset[self.pin.pin_bank() as usize].write(|w| unsafe { w.dirsetp().bits(self.bit()) })
+    }
+
+    pub fn set_as_input(&mut self) {
+        self.set_as_digital();
+        gpio_reg().dirclr[self.pin.pin_bank() as usize].write(|w| unsafe { w.dirclrp().bits(self.bit()) })
+    }
+}
+
+/// Sealed trait for pins. This trait is sealed and cannot be implemented outside of this crate.
+pub(crate) trait SealedPin: Sized {
+    fn pin_bank(&self) -> Bank;
+    fn pin_number(&self) -> u8;
+}
+
+/// Interface for a Pin that can be configured by an [Input] or [Output] driver, or converted to an
+/// [AnyPin]. By default, this trait is sealed and cannot be implemented outside of the
+/// `embassy-nxp` crate due to the [SealedPin] trait.
+#[allow(private_bounds)]
+pub trait Pin: Peripheral<P = Self> + Into<AnyPin> + SealedPin + Sized + 'static {
+    /// Degrade to a generic pin struct
+    fn degrade(self) -> AnyPin {
+        AnyPin {
+            pin_bank: self.pin_bank(),
+            pin_number: self.pin_number(),
+        }
+    }
+
+    /// Returns the pin number within a bank
+    #[inline]
+    fn pin(&self) -> u8 {
+        self.pin_number()
+    }
+
+    /// Returns the bank of this pin
+    #[inline]
+    fn bank(&self) -> Bank {
+        self.pin_bank()
+    }
+}
+
+/// Type-erased GPIO pin.
+pub struct AnyPin {
+    pin_bank: Bank,
+    pin_number: u8,
+}
+
+impl AnyPin {
+    /// Unsafely create a new type-erased pin.
+    ///
+    /// # Safety
+    ///
+    /// You must ensure that you’re only using one instance of this type at a time.
+    pub unsafe fn steal(pin_bank: Bank, pin_number: u8) -> Self {
+        Self { pin_bank, pin_number }
+    }
+}
+
+impl_peripheral!(AnyPin);
+
+impl Pin for AnyPin {}
+impl SealedPin for AnyPin {
+    #[inline]
+    fn pin_bank(&self) -> Bank {
+        self.pin_bank
+    }
+
+    #[inline]
+    fn pin_number(&self) -> u8 {
+        self.pin_number
+    }
+}
+
+macro_rules! impl_pin {
+    ($name:ident, $bank:expr, $pin_num:expr) => {
+        impl Pin for peripherals::$name {}
+        impl SealedPin for peripherals::$name {
+            #[inline]
+            fn pin_bank(&self) -> Bank {
+                $bank
+            }
+
+            #[inline]
+            fn pin_number(&self) -> u8 {
+                $pin_num
+            }
+        }
+
+        impl From<peripherals::$name> for crate::gpio::AnyPin {
+            fn from(val: peripherals::$name) -> Self {
+                crate::gpio::Pin::degrade(val)
+            }
+        }
+    };
+}
+
+impl_pin!(PIO0_0, Bank::Bank0, 0);
+impl_pin!(PIO0_1, Bank::Bank0, 1);
+impl_pin!(PIO0_2, Bank::Bank0, 2);
+impl_pin!(PIO0_3, Bank::Bank0, 3);
+impl_pin!(PIO0_4, Bank::Bank0, 4);
+impl_pin!(PIO0_5, Bank::Bank0, 5);
+impl_pin!(PIO0_6, Bank::Bank0, 6);
+impl_pin!(PIO0_7, Bank::Bank0, 7);
+impl_pin!(PIO0_8, Bank::Bank0, 8);
+impl_pin!(PIO0_9, Bank::Bank0, 9);
+impl_pin!(PIO0_10, Bank::Bank0, 10);
+impl_pin!(PIO0_11, Bank::Bank0, 11);
+impl_pin!(PIO0_12, Bank::Bank0, 12);
+impl_pin!(PIO0_13, Bank::Bank0, 13);
+impl_pin!(PIO0_14, Bank::Bank0, 14);
+impl_pin!(PIO0_15, Bank::Bank0, 15);
+impl_pin!(PIO0_16, Bank::Bank0, 16);
+impl_pin!(PIO0_17, Bank::Bank0, 17);
+impl_pin!(PIO0_18, Bank::Bank0, 18);
+impl_pin!(PIO0_19, Bank::Bank0, 19);
+impl_pin!(PIO0_20, Bank::Bank0, 20);
+impl_pin!(PIO0_21, Bank::Bank0, 21);
+impl_pin!(PIO0_22, Bank::Bank0, 22);
+impl_pin!(PIO0_23, Bank::Bank0, 23);
+impl_pin!(PIO0_24, Bank::Bank0, 24);
+impl_pin!(PIO0_25, Bank::Bank0, 25);
+impl_pin!(PIO0_26, Bank::Bank0, 26);
+impl_pin!(PIO0_27, Bank::Bank0, 27);
+impl_pin!(PIO0_28, Bank::Bank0, 28);
+impl_pin!(PIO0_29, Bank::Bank0, 29);
+impl_pin!(PIO0_30, Bank::Bank0, 30);
+impl_pin!(PIO0_31, Bank::Bank0, 31);
+impl_pin!(PIO1_0, Bank::Bank1, 0);
+impl_pin!(PIO1_1, Bank::Bank1, 1);
+impl_pin!(PIO1_2, Bank::Bank1, 2);
+impl_pin!(PIO1_3, Bank::Bank1, 3);
+impl_pin!(PIO1_4, Bank::Bank1, 4);
+impl_pin!(PIO1_5, Bank::Bank1, 5);
+impl_pin!(PIO1_6, Bank::Bank1, 6);
+impl_pin!(PIO1_7, Bank::Bank1, 7);
+impl_pin!(PIO1_8, Bank::Bank1, 8);
+impl_pin!(PIO1_9, Bank::Bank1, 9);
+impl_pin!(PIO1_10, Bank::Bank1, 10);
+impl_pin!(PIO1_11, Bank::Bank1, 11);
+impl_pin!(PIO1_12, Bank::Bank1, 12);
+impl_pin!(PIO1_13, Bank::Bank1, 13);
+impl_pin!(PIO1_14, Bank::Bank1, 14);
+impl_pin!(PIO1_15, Bank::Bank1, 15);
+impl_pin!(PIO1_16, Bank::Bank1, 16);
+impl_pin!(PIO1_17, Bank::Bank1, 17);
+impl_pin!(PIO1_18, Bank::Bank1, 18);
+impl_pin!(PIO1_19, Bank::Bank1, 19);
+impl_pin!(PIO1_20, Bank::Bank1, 20);
+impl_pin!(PIO1_21, Bank::Bank1, 21);
+impl_pin!(PIO1_22, Bank::Bank1, 22);
+impl_pin!(PIO1_23, Bank::Bank1, 23);
+impl_pin!(PIO1_24, Bank::Bank1, 24);
+impl_pin!(PIO1_25, Bank::Bank1, 25);
+impl_pin!(PIO1_26, Bank::Bank1, 26);
+impl_pin!(PIO1_27, Bank::Bank1, 27);
+impl_pin!(PIO1_28, Bank::Bank1, 28);
+impl_pin!(PIO1_29, Bank::Bank1, 29);
+impl_pin!(PIO1_30, Bank::Bank1, 30);
+impl_pin!(PIO1_31, Bank::Bank1, 31);