Add input support, examples, SIO/PADS ownership

Sorry this is a large commit :( This adds support for input pins, including pulling them high or low. It also adds two examples: the start of a classic blinky LED example, and an example for reading input.
2024-12-23 20:51:31 +11:00 · 2021-04-24 16:18:57 -05:00 · 2021-04-24 16:18:57 -05:00 · 2c3a0956fa
parent 45580ec4c8
commit 2c3a0956fa
8 changed files with 253 additions and 185 deletions
--- a/.cargo/config
+++ b/.cargo/config
@ -1,3 +1,11 @@
 [build]
 # Instruction set of Cortex-M0+
 target = "thumbv6m-none-eabi"
+
+[target.'cfg(all(target_arch = "arm", target_os = "none"))']
+rustflags = [
+    "-C", "link-arg=--nmagic",
+    "-C", "link-arg=-Tlink.x",
+    "-C", "inline-threshold=5",
+    "-C", "no-vectorize-loops",
+]
--- a/.gitignore
+++ b/.gitignore
@ -1,2 +1,3 @@
 .idea/
 target
+Cargo.lock
--- a/Cargo.lock
+++ b/Cargo.lock
@ -1,117 +0,0 @@
-# This file is automatically @generated by Cargo.
-# It is not intended for manual editing.
-[[package]]
-name = "bare-metal"
-version = "0.2.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5deb64efa5bd81e31fcd1938615a6d98c82eafcbcd787162b6f63b91d6bac5b3"
-dependencies = [
- "rustc_version",
-]
-
-[[package]]
-name = "bitfield"
-version = "0.13.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46afbd2983a5d5a7bd740ccb198caf5b82f45c40c09c0eed36052d91cb92e719"
-
-[[package]]
-name = "cortex-m"
-version = "0.7.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "643a210c1bdc23d0db511e2a576082f4ff4dcae9d0c37f50b431b8f8439d6d6b"
-dependencies = [
- "bare-metal",
- "bitfield",
- "embedded-hal",
- "volatile-register",
-]
-
-[[package]]
-name = "embedded-hal"
-version = "0.2.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa998ce59ec9765d15216393af37a58961ddcefb14c753b4816ba2191d865fcb"
-dependencies = [
- "nb 0.1.3",
- "void",
-]
-
-[[package]]
-name = "nb"
-version = "0.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "801d31da0513b6ec5214e9bf433a77966320625a37860f910be265be6e18d06f"
-dependencies = [
- "nb 1.0.0",
-]
-
-[[package]]
-name = "nb"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "546c37ac5d9e56f55e73b677106873d9d9f5190605e41a856503623648488cae"
-
-[[package]]
-name = "rp2040-hal"
-version = "0.1.0"
-dependencies = [
- "cortex-m",
- "embedded-hal",
- "nb 1.0.0",
- "rp2040-pac",
-]
-
-[[package]]
-name = "rp2040-pac"
-version = "0.1.1"
-source = "git+https://github.com/rp-rs/rp2040-pac?branch=main#f4339cb856f082970767099a0079259f333cdc7e"
-dependencies = [
- "cortex-m",
- "vcell",
-]
-
-[[package]]
-name = "rustc_version"
-version = "0.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
-dependencies = [
- "semver",
-]
-
-[[package]]
-name = "semver"
-version = "0.9.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
-dependencies = [
- "semver-parser",
-]
-
-[[package]]
-name = "semver-parser"
-version = "0.7.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
-
-[[package]]
-name = "vcell"
-version = "0.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "77439c1b53d2303b20d9459b1ade71a83c716e3f9c34f3228c00e6f185d6c002"
-
-[[package]]
-name = "void"
-version = "1.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
-
-[[package]]
-name = "volatile-register"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0d67cb4616d99b940db1d6bd28844ff97108b498a6ca850e5b6191a532063286"
-dependencies = [
- "vcell",
-]
--- a/memory.x
+++ b/memory.x
@ -0,0 +1,13 @@
+MEMORY {
+    BOOT2 : ORIGIN = 0x10000000, LENGTH = 0x100
+    FLASH : ORIGIN = 0x10000100, LENGTH = 2048K - 0x100
+    RAM   : ORIGIN = 0x20000000, LENGTH = 256K
+}
+
+SECTIONS {
+    /* ### Boot loader */
+    .boot2 ORIGIN(BOOT2) :
+    {
+        KEEP(*(.boot2));
+    } > BOOT2
+} INSERT BEFORE .text;
--- a/rp2040-hal/Cargo.toml
+++ b/rp2040-hal/Cargo.toml
@ -11,6 +11,11 @@ license = "MIT OR Apache-2.0"

 [dependencies]
 cortex-m = "0.7.1"
-embedded-hal = "0.2.4"
+embedded-hal = { version = "0.2.4", features = ["unproven"] }
 nb = "1.0.0"
 rp2040-pac = { git = "https://github.com/rp-rs/rp2040-pac", branch="main" }
+
+[dev-dependencies]
+cortex-m-rt = "0.6.13"
+panic-halt = "0.2.0"
+rp2040-boot2 = { git = "https://github.com/rp-rs/rp2040-boot2-rs", branch="main" }
--- a/rp2040-hal/examples/blinky.rs
+++ b/rp2040-hal/examples/blinky.rs
@ -0,0 +1,31 @@
+//! Blinks the LED on a Pico board
+//!
+//! This will blink an LED attached to GP25, which is the pin the Pico uses for the on-board LED.
+#![no_std]
+#![no_main]
+
+use panic_halt as _;
+
+use cortex_m_rt::entry;
+
+#[link_section = ".boot2"]
+#[used]
+pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER;
+
+use embedded_hal::digital::v2::OutputPin;
+use rp2040_hal::prelude::*;
+
+#[entry]
+fn main() -> ! {
+    let mut pac = rp2040_pac::Peripherals::take().unwrap();
+
+    let pins = pac.IO_BANK0.split(pac.PADS_BANK0, pac.SIO, &mut pac.RESETS);
+    let mut led_pin = pins.gpio25.into_output();
+
+    loop {
+        led_pin.set_low().unwrap();
+        // TODO: I dare not use delays until we've got clocks running
+        led_pin.set_high().unwrap();
+        // TODO: Other delay
+    }
+}
--- a/rp2040-hal/examples/gpio_in_out.rs
+++ b/rp2040-hal/examples/gpio_in_out.rs
@ -0,0 +1,36 @@
+//! Toggle LED based on GPIO input
+//!
+//! This will control an LED on GP25 based on a button hooked up to GP15. The button should be tied
+//! to ground, as the input pin is pulled high internally by this example. When the button is
+//! pressed, the LED will turn off.
+#![no_std]
+#![no_main]
+
+use panic_halt as _;
+
+use cortex_m_rt::entry;
+
+#[link_section = ".boot2"]
+#[used]
+pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER;
+
+use embedded_hal::digital::v2::{InputPin, OutputPin};
+use rp2040_hal::prelude::*;
+
+#[entry]
+fn main() -> ! {
+    let mut pac = rp2040_pac::Peripherals::take().unwrap();
+
+    let pins = pac.IO_BANK0.split(pac.PADS_BANK0, pac.SIO, &mut pac.RESETS);
+    let mut led_pin = pins.gpio25.into_output();
+    let mut button_pin = pins.gpio15.into_input();
+    button_pin.pull_high();
+
+    loop {
+        if button_pin.is_high().unwrap() {
+            led_pin.set_high().unwrap();
+        } else {
+            led_pin.set_low().unwrap();
+        }
+    }
+}
--- a/rp2040-hal/src/gpio.rs
+++ b/rp2040-hal/src/gpio.rs
@ -7,39 +7,50 @@
 //! ```rust
 //! let mut pac = rp2040_pac::Peripherals::take().unwrap();
 //!
-//! let pins = pac.IO_BANK0.split(&mut pac.RESETS);
-//! let mut led_pin = pins.gpio25.into_output(&mut pac.PADS_BANK0, &mut pac.SIO);
-//!  led_pin.set_low().unwrap();
+//! let pins = pac.IO_BANK0.split(pac.PADS_BANK0, pac.SIO, &mut pac.RESETS);
+//! let mut led_pin = pins.gpio25.into_output();
+//! led_pin.set_high().unwrap();
 //! ```
-use core::convert::Infallible;
-use core::marker::PhantomData;
-use embedded_hal::digital::v2::OutputPin;
-
-pub struct Floating;
-pub struct Input<MODE> {
-    _mode: PhantomData<MODE>,
-}
+pub struct Input;
 pub struct Output;
+pub struct Unknown;

-pub trait GpioExt {
+pub trait GpioExt<PADS, SIO> {
    type Parts;

    // TODO: Do we need a marker to check that clocks are up?
-    fn split(self, reset: &mut rp2040_pac::RESETS) -> Self::Parts;
+    fn split(self, pads: PADS, sio: SIO, reset: &mut rp2040_pac::RESETS) -> Self::Parts;
 }

+// Magic numbers from the datasheet
+// const FUNCTION_SPI: u8 = 1;
+// const FUNCTION_UART: u8 = 2;
+// const FUNCTION_I2C: u8 = 3;
+// const FUNCTION_PWM: u8 = 4;
 const FUNCTION_SIO: u8 = 5;
+// const FUNCTION_PIO0: u8 = 6;
+// const FUNCTION_PIO1: u8 = 7;
+// const FUNCTION_CLOCK: u8 = 8;
+// const FUNCTION_USB: u8 = 9;

 macro_rules! gpio {
-    ($GPIOX:ident, $gpiox:ident, $PADSX:ident, [
+    ($GPIOX:ident, $gpiox:ident, $PADSX:ident, $padsx:ident, [
        $($PXi:ident: ($pxi:ident, $i:expr),)+
    ]) => {
-        impl GpioExt for pac::$GPIOX {
+        mod $gpiox {
+            use core::convert::Infallible;
+            use core::marker::PhantomData;
+            use embedded_hal::digital::v2::{InputPin, OutputPin, StatefulOutputPin};
+            use super::{GpioExt, Input, Output, Unknown, FUNCTION_SIO};
+
+            impl GpioExt<pac::$PADSX, pac::SIO> for pac::$GPIOX {
                type Parts = Parts;

-            fn split(self, resets: &mut pac::RESETS) -> Parts {
+                fn split(self, pads: pac::$PADSX, sio: pac::SIO, resets: &mut pac::RESETS) -> Parts {
                    resets.reset.modify(|_, w| w.$gpiox().clear_bit());
                    Parts {
+                        _pads: pads,
+                        _sio: sio,
                        $(
                            $pxi: $PXi { _mode: PhantomData },
                        )+
@ -48,29 +59,67 @@ macro_rules! gpio {
            }

            pub struct Parts {
+                _pads: pac::$PADSX,
+                _sio: pac::SIO,
                $(
-                pub $pxi: $PXi<Input<Floating>>,
+                    pub $pxi: $PXi<Unknown>,
                )+
            }

+            // Puts pad in default state as far as this crate is concerned:
+            // - Input is enabled
+            // - Output is enabled (if also set in SIO)
+            // - Pull up/down is disabled
+            //
+            // TODO: Drive strength, smitty, slewing
+            fn setup_pad_io(pads: &pac::$padsx::RegisterBlock, index: usize) {
+                pads.gpio[index].modify(|_, w| w.ie().set_bit().od().clear_bit().pue().clear_bit().pde().clear_bit());
+            }
+
+            fn set_gpio_function(gpios: &pac::$gpiox::RegisterBlock, index: usize, function: u8) {
+                gpios.gpio[index]
+                    .gpio_ctrl
+                    .write_with_zero(|x| unsafe { x.funcsel().bits(function) });
+            }
+
            $(
                pub struct $PXi<MODE> {
                    _mode: PhantomData<MODE>,
                }

+                // Safety: We own our $i slice of padsx, gpiox, and sio because the
+                // construction of Parts assumes ownership of all 3 and will not release
+                // them. Thus several of the methods below will reconstruct these objects
+                // as-needed
+
                impl<MODE> $PXi<MODE> {
                    pub fn into_output(
                        self,
-                    pads: &mut pac::$PADSX,
-                    sio: &mut pac::SIO,
                    ) -> $PXi<Output> {
-                    pads.gpio[$i].modify(|_, w| w.ie().set_bit().od().clear_bit());
                        unsafe {
-                        (*pac::$GPIOX::ptr()).gpio[$i]
-                            .gpio_ctrl
-                            .write_with_zero(|x| x.funcsel().bits(FUNCTION_SIO));
+                            setup_pad_io(&*pac::$PADSX::ptr(), $i);
+                        }
+                        unsafe {
+                            set_gpio_function(&*pac::$GPIOX::ptr(), $i, FUNCTION_SIO);
+                        }
+                        unsafe {
+                            (*pac::SIO::ptr()).gpio_oe_set.write(|x| { x.bits(1 << $i) });
+                        }
+                        $PXi { _mode: PhantomData }
+                    }
+
+                    pub fn into_input(
+                        self,
+                    ) -> $PXi<Input> {
+                        unsafe {
+                            setup_pad_io(&*pac::$PADSX::ptr(), $i);
+                        }
+                        unsafe {
+                            set_gpio_function(&*pac::$GPIOX::ptr(), $i, FUNCTION_SIO);
+                        }
+                        unsafe {
+                            (*pac::SIO::ptr()).gpio_oe_clr.write(|x| { x.bits(1 << $i) });
                        }
-                    sio.gpio_oe.modify(|_, x| unsafe { x.bits(1 << $i) });
                        $PXi { _mode: PhantomData }
                    }
                }
@ -92,12 +141,54 @@ macro_rules! gpio {
                        Ok(())
                    }
                }
+
+                impl StatefulOutputPin for $PXi<Output> {
+                    fn is_set_low(&self) -> Result<bool, Self::Error> {
+                        Ok(!self.is_set_high()?)
+                    }
+
+                    fn is_set_high(&self) -> Result<bool, Self::Error> {
+                        unsafe {
+                            Ok((*pac::SIO::ptr()).gpio_out_set.read().bits() & (1 << $i) != 0)
+                        }
+                    }
+                }
+
+                // TODO: Don't allow Unknown since we need to fix up the pad at least
+                impl<MODE> InputPin for $PXi<MODE> {
+                    type Error = Infallible;
+
+                    fn is_low(&self) -> Result<bool, Self::Error> {
+                        Ok(!self.is_high()?)
+                    }
+
+                    fn is_high(&self) -> Result<bool, Self::Error> {
+                        unsafe {
+                            Ok((*pac::SIO::ptr()).gpio_in.read().bits() & (1 << $i) != 0)
+                        }
+                    }
+                }
+
+                impl $PXi<Input> {
+                    pub fn pull_high(&mut self) {
+                        unsafe {
+                            (*pac::$PADSX::ptr()).gpio[$i].modify(|_, w| w.pue().set_bit().pde().clear_bit());
+                        }
+                    }
+
+                    pub fn pull_low(&mut self) {
+                        unsafe {
+                            (*pac::$PADSX::ptr()).gpio[$i].modify(|_, w| w.pue().clear_bit().pde().set_bit());
+                        }
+                    }
+                }
            )+
+        }
    };
 }

 gpio!(
-    IO_BANK0, io_bank0, PADS_BANK0, [
+    IO_BANK0, io_bank0, PADS_BANK0, pads_bank0, [
        Gpio0: (gpio0, 0),
        Gpio1: (gpio1, 1),
        Gpio2: (gpio2, 2),