PoC gpio driver for all output enabled pins using the embedded-hal traits

Author: MabezDev

Cargo.toml

@@ -7,3 +7,9 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+# esp32 = { version = "0.2.1" }
+esp32 = { path = "../../hal/esp32-pac"}
+
+[dependencies.embedded-hal]
+features = ["unproven"]
+version = "0.2.3"

src/gpio.rs

@@ -0,0 +1,205 @@
+
+use core::marker::PhantomData;
+use core::convert::Infallible;
+
+use esp32::{GPIO, IO_MUX};
+use embedded_hal::digital::v2::OutputPin;
+
+/// Extension trait to split a GPIO peripheral in independent pins and registers
+pub trait GpioExt {
+    /// The to split the GPIO into
+    type Parts;
+
+    /// Splits the GPIO block into independent pins and registers
+    fn split(self) -> Self::Parts;
+}
+
+/// Input mode (type state)
+pub struct Input<MODE> {
+    _mode: PhantomData<MODE>,
+}
+
+/// Floating input (type state)
+pub struct Floating;
+
+/// Pulled down input (type state)
+pub struct PullDown;
+
+/// Pulled up input (type state)
+pub struct PullUp;
+
+/// Open drain input or output (type state)
+pub struct OpenDrain;
+
+/// Push pull output (type state)
+pub struct PushPull;
+
+/// Analog mode (type state)
+pub struct Analog;
+
+/// Output mode (type state)
+pub struct Output<MODE> {
+    _mode: PhantomData<MODE>,
+}
+
+macro_rules! gpio {
+    ($GPIO:ident: [
+        $($pxi:ident: ($pname:ident, $MODE:ty),)+
+    ]) => {
+
+        impl GpioExt for $GPIO {
+            type Parts = Parts;
+
+            fn split(self) -> Self::Parts {
+                Parts {
+                    $(
+                        $pname: $pxi { _mode: PhantomData },
+                    )+
+                }
+            }
+        }
+
+        pub struct Parts {
+            $(
+                /// Pin
+                pub $pname: $pxi<$MODE>,
+            )+
+        }
+
+        // create all the pins, we can also add functionality
+        // applicable to all pin states here
+        $(
+            /// Pin
+            pub struct $pxi<MODE> {
+                _mode: PhantomData<MODE>,
+            }
+        )+
+
+    };
+}
+
+// All info on reset state pulled from 4.10 IO_MUX Pad List in the reference manual
+gpio! {
+   GPIO: [
+       Gpio0: (gpio0, Input<PullUp>),
+       Gpio1: (gpio1, Input<PullUp>),
+       Gpio2: (gpio2, Input<PullDown>),
+       Gpio3: (gpio3, Input<PullUp>),
+       Gpio4: (gpio4, Input<PullDown>),
+       Gpio5: (gpio5, Input<PullUp>),
+       Gpio6: (gpio6, Input<PullUp>),
+       Gpio7: (gpio7, Input<PullUp>),
+       Gpio8: (gpio8, Input<PullUp>),
+       Gpio9: (gpio9, Input<PullUp>),
+       Gpio10: (gpio10, Input<PullUp>),
+       Gpio11: (gpio11, Input<PullUp>),
+       Gpio12: (gpio12, Input<PullDown>),
+       Gpio13: (gpio13, Input<Floating>),
+       Gpio14: (gpio14, Input<Floating>),
+       Gpio15: (gpio15, Input<PullUp>),
+       Gpio16: (gpio16, Input<Floating>),
+       Gpio17: (gpio17, Input<Floating>),
+       Gpio18: (gpio18, Input<Floating>),
+       Gpio19: (gpio19, Input<Floating>),
+       Gpio20: (gpio20, Input<Floating>),
+       Gpio21: (gpio21, Input<Floating>),
+       Gpio22: (gpio22, Input<Floating>),
+       Gpio23: (gpio23, Input<Floating>),
+       // TODO these pins have a reset mode of 0 (apart from Gpio27), 
+       // input disable, does that mean they are actually in output mode on reset?
+       Gpio25: (gpio25, Input<Floating>),
+       Gpio26: (gpio26, Input<Floating>),
+       Gpio27: (gpio27, Input<Floating>),
+    // TODO all these really missing?
+    //    Gpio24: (gpio24, Input<Floating>),
+    //    Gpio28: (gpio28, Input<Floating>),
+    //    Gpio29: (gpio29, Input<Floating>),
+    //    Gpio30: (gpio30, Input<Floating>),
+    //    Gpio31: (gpio31, Input<Floating>),
+       Gpio32: (gpio32, Input<Floating>),
+       Gpio33: (gpio33, Input<Floating>),
+       Gpio34: (gpio34, Input<Floating>),
+       Gpio35: (gpio35, Input<Floating>),
+       Gpio36: (gpio36, Input<Floating>),
+       Gpio37: (gpio37, Input<Floating>),
+       Gpio38: (gpio38, Input<Floating>),
+       Gpio39: (gpio39, Input<Floating>),
+   ]
+}
+
+macro_rules! impl_output {
+    ($en:ident, $outs:ident, $outc:ident, [
+        // index, gpio pin name, funcX name, iomux pin name, iomux mcu_sel bits
+        $($pxi:ident: ($i:expr, $pin:ident, $funcXout:ident, $iomux:ident, $mcu_sel_bits:expr),)+
+    ]) => {
+        $(
+            impl<MODE> OutputPin for $pxi<Output<MODE>> {
+                type Error = Infallible;
+
+                fn set_high(&mut self) -> Result<(), Self::Error> {
+                    // NOTE(unsafe) atomic write to a stateless register
+                    unsafe { (*GPIO::ptr()).$outs.write(|w| w.bits(1 << $i)) };
+                    Ok(())
+                }
+
+                fn set_low(&mut self) -> Result<(), Self::Error> {
+                    // NOTE(unsafe) atomic write to a stateless register
+                    unsafe { (*GPIO::ptr()).$outc.write(|w| w.bits(1 << $i)) };
+                    Ok(())
+                }
+            }
+
+            impl<MODE> $pxi<MODE> {
+                pub fn into_push_pull_output(self) -> $pxi<Output<PushPull>> {
+                    let gpio = unsafe{ &*GPIO::ptr() };
+                    let iomux = unsafe{ &*IO_MUX::ptr() };
+                    gpio.$en.modify(|_, w| unsafe  { w.bits(0x1 << $i) });
+                    gpio.$funcXout.modify(|_, w| unsafe { w.bits(0x100) });
+
+                    iomux.$iomux.modify(|_, w| unsafe { w.mcu_sel().bits($mcu_sel_bits) });
+                    $pxi { _mode: PhantomData }
+                }
+            }
+        )+
+    };
+}
+
+impl_output! {
+    enable_w1ts, out_w1ts, out_w1tc, [
+        Gpio0: (0, pin0, func0_out_sel_cfg, gpio0, 0b00),
+        Gpio1: (1, pin1, func1_out_sel_cfg, u0txd, 0b10),
+        Gpio2: (2, pin2, func2_out_sel_cfg, gpio2, 0b00),
+        Gpio3: (3, pin3, func3_out_sel_cfg, u0rxd, 0b10),
+        Gpio4: (4, pin4, func4_out_sel_cfg, gpio4, 0b10),
+        Gpio5: (5, pin5, func5_out_sel_cfg, gpio5, 0b10),
+        Gpio6: (6, pin6, func6_out_sel_cfg, sd_clk, 0b10),
+        Gpio7: (7, pin7, func7_out_sel_cfg, sd_data0, 0b10),
+        Gpio8: (8, pin8, func8_out_sel_cfg, sd_data1, 0b10),
+        Gpio9: (9, pin9, func9_out_sel_cfg, sd_data2, 0b10),
+        Gpio10: (10, pin10, func10_out_sel_cfg, sd_data3, 0b10),
+        Gpio11: (11, pin11, func11_out_sel_cfg, sd_cmd, 0b10),
+        Gpio12: (12, pin12, func12_out_sel_cfg, mtdi, 0b10),
+        Gpio13: (13, pin13, func13_out_sel_cfg, mtck, 0b10),
+        Gpio14: (14, pin14, func14_out_sel_cfg, mtms, 0b10),
+        Gpio15: (15, pin15, func15_out_sel_cfg, mtdo, 0b10),
+        Gpio16: (16, pin16, func16_out_sel_cfg, gpio16, 0b10),
+        Gpio17: (17, pin17, func17_out_sel_cfg, gpio17, 0b10),
+        Gpio18: (18, pin18, func18_out_sel_cfg, gpio18, 0b10),
+        Gpio19: (19, pin19, func19_out_sel_cfg, gpio19, 0b10),
+        Gpio20: (20, pin20, func20_out_sel_cfg, gpio20, 0b10),
+        Gpio21: (21, pin21, func21_out_sel_cfg, gpio21, 0b10),
+        Gpio22: (22, pin22, func22_out_sel_cfg, gpio22, 0b10),
+        Gpio23: (23, pin23, func23_out_sel_cfg, gpio23, 0b10),
+        Gpio25: (25, pin25, func25_out_sel_cfg, gpio25, 0b10),
+        Gpio26: (26, pin26, func26_out_sel_cfg, gpio26, 0b10),
+        Gpio27: (27, pin27, func27_out_sel_cfg, gpio27, 0b10),
+    ]
+}
+
+impl_output! {
+    enable1_w1ts, out1_w1ts, out1_w1tc, [
+        Gpio32: (0, pin32, func32_out_sel_cfg, gpio32, 0b00),
+        Gpio33: (1, pin33, func33_out_sel_cfg, gpio33, 0b00),
+        /* Deliberately omitting 34-39 as these can *only* be inputs */
+    ]
+}

src/lib.rs

@@ -0,0 +1,4 @@
+#![no_std]
+
+pub use embedded_hal as ehal;
+pub mod gpio;