progress

.gitignore

@@ -4,12 +4,4 @@
 Cargo.lock
 target/
 
-# editor files
-.vscode/*
-!.vscode/*.md
-!.vscode/*.svd
-!.vscode/launch.json
-!.vscode/tasks.json
-!.vscode/extensions.json
-
 .history/

.vscode/settings.json

@@ -0,0 +1,5 @@
+// https://github.com/rust-lang/vscode-rust/issues/729#issuecomment-635977755
+{
+    "rust-analyzer.cargo.target": "thumbv7em-none-eabihf",
+    "rust-analyzer.checkOnSave.allTargets": false
+}

Cargo.toml

@@ -24,6 +24,9 @@ panic-halt = "0.2.0"
 # features = ["stm32f303", "rt"]
 # version = "0.7.1"
 
+[lib]
+path = "src/lib/mod.rs"
+
 # this lets you use `cargo fix`!
 [[bin]]
 name = "test-cortex-m4-rust"

src/lib.rs

@@ -1,56 +0,0 @@
-#![no_std]
-
-pub struct Board;
-
-impl Board {
-    pub fn setup_gpio_port(port: Port, options: PortSetup) -> PortIO {
-        PortIO
-    }
-}
-
-pub enum Port {
-    A,
-    F,
-}
-
-pub struct PortSetup;
-
-pub struct PortIO;
-
-impl PortIO {
-    pub fn setup_pin(pin: Pin, options: PinSetup) -> PinIO {
-        PinIO
-    }
-}
-
-pub enum Pin {
-    Zero = 0,
-    One = 1,
-    Two = 2,
-    Three = 3,
-    Four = 4,
-    Five = 5,
-    Six = 6,
-    Seven = 7,
-}
-
-pub struct PinSetup;
-
-pub struct PinIO;
-
-impl PinIO {
-    pub fn clear(&mut self) {
-        todo!();
-    }
-    pub fn set(&mut self) {
-        todo!();
-    }
-    pub fn toggle(&mut self) {
-        todo!();
-    }
-}
-
-
-pub fn setup_board() -> Board {
-    Board
-}

src/lib/memory.rs

@@ -0,0 +1,83 @@
+//! Interact with memory
+
+use core::ptr;
+
+use crate::{Bit, L};
+
+pub unsafe fn read(address: *mut u32) -> u32 {
+    ptr::read_volatile(address)
+}
+pub unsafe fn write(address: *mut u32, new: u32) {
+    ptr::write_volatile(address, new);
+}
+
+pub unsafe fn update<Updater: Fn(u32) -> u32>(address: *mut u32, updater: Updater) {
+    write(address, updater(read(address)));
+}
+
+pub unsafe fn read_bits<const N: usize>(address: *mut u32, bits: &[u32; N]) -> [bool; N] {
+    let current = read(address);
+    let mut result = [L; N];
+
+    // TODO: look up accumulate or reduce or something
+    for (i, bit) in bits.iter().enumerate() {
+        result[i] = (current & (1 << bit)) != 0;
+    }
+
+    result
+}
+pub unsafe fn write_bits<const N: usize>(address: *mut u32, bits: &[u32; N], values: [bool; N]) {
+    update(address, |current| {
+        let mut new = current;
+        // TODO: look up accumulate or reduce or something
+        for (bit, set) in bits.iter().zip(values) {
+            if set {
+                new |= (1 << bit);
+            } else {
+                new &= !(1 << bit);
+            }
+        }
+        new
+    })
+}
+
+pub unsafe fn update_bits<const N: usize, Updater: Fn([bool; N]) -> [bool; N]>(address: *mut u32, bits: &[Bit; N], updater: Updater) {
+    write_bits(address, bits, updater(read_bits(address, bits)))
+}
+
+pub unsafe fn set_bits(address: *mut u32, bits: &[Bit]) {
+    update(address, |current| {
+        let mut new = current;
+
+        // TODO: look up accumulate or reduce or something
+        for bit in bits {
+            new |= (1 << bit);
+        }
+
+        new
+    })
+}
+pub unsafe fn clear_bits(address: *mut u32, bits: &[Bit]) {
+    update(address, |current| {
+        let mut new = current;
+
+        // TODO: look up accumulate or reduce or something
+        for bit in bits {
+            new &= !(1 << bit);
+        }
+
+        new
+    })
+}
+pub unsafe fn toggle_bits(address: *mut u32, bits: &[Bit]) {
+    update(address, |current| {
+        let mut new = current;
+
+        // TODO: look up accumulate or reduce or something
+        for bit in bits {
+            new ^= (1 << bit);
+        }
+
+        new
+    })
+}

src/lib/mod.rs

@@ -0,0 +1,343 @@
+#![no_std]
+
+mod memory;
+mod registers;
+
+pub const H: bool = true;
+pub const L: bool = false;
+
+pub struct Board;
+// TODO: check page 704 for timers
+// TODO: impl Drop trait so that tasks all run before the main function ends?
+
+impl Board {
+    pub fn setup_gpio_port(&self, port: Port, options: PortSetup) -> PortIO {
+        let port_io = PortIO { port };
+
+        unsafe {
+            memory::set_bits(registers::system::RCGCGPIO, &[port_io.run_mode_clock_gate_control()]);
+        }
+        
+        port_io
+    }
+}
+
+// Page 684 of the data sheet for how the lock mechanism works
+const UNLOCK: u32 = 0x4C4F434B;
+
+pub enum Port {
+    A,
+    B,
+    C,
+    D,
+    E,
+    F,
+}
+
+pub struct PortSetup;
+
+pub struct PortIO {
+    port: Port,
+}
+
+impl PortIO {
+    /// The memory address of the analog mode select (AMSEL) register for this port
+    fn analog_mode_select(&self) -> *mut u32 {
+        match self.port {
+            Port::A => registers::gpio::amsel::PORT_A,
+            Port::F => registers::gpio::amsel::PORT_F,
+            _ => todo!(),
+        }
+    }
+
+    /// The memory address of the commit (CR register for this port
+    fn commit(&self) -> *mut u32 {
+        match self.port {
+            Port::A => registers::gpio::cr::PORT_A,
+            Port::F => registers::gpio::cr::PORT_F,
+            _ => todo!(),
+        }
+    }
+
+    /// The memory address of the data (DATA) register for this port
+    fn data(&self) -> *mut u32 {
+        match self.port {
+            Port::A => registers::gpio::data::PORT_A,
+            Port::F => registers::gpio::data::PORT_F,
+            _ => todo!(),
+        }
+    }
+
+    /// The memory address of the direction (DIR) register for this port
+    fn direction(&self) -> *mut u32 {
+        match self.port {
+            Port::A => registers::gpio::dir::PORT_A,
+            Port::F => registers::gpio::dir::PORT_F,
+            _ => todo!(),
+        }
+    }
+
+    /// The memory address of the lock (LOCK) register
+    fn lock(&self) -> *mut u32 {
+        match self.port {
+            Port::A => registers::gpio::lock::PORT_A,
+            Port::F => registers::gpio::lock::PORT_F,
+            _ => todo!(),
+        }
+    }
+
+    /// The memory address of the port control (PCTL) register for this port
+    fn port_control(&self) -> *mut u32 {
+        match self.port {
+            Port::A => registers::gpio::pctl::PORT_A,
+            Port::F => registers::gpio::pctl::PORT_F,
+            _ => todo!(),
+
+        }
+    }
+
+    /// The memory address of the pull-down resistor select (PDR) register for this port
+    fn pull_down_select(&self) -> *mut u32 {
+        match self.port {
+            Port::A => registers::gpio::pdr::PORT_A,
+            Port::F => registers::gpio::pdr::PORT_F,
+            _ => todo!(),
+        }
+    }
+
+    /// The memory address of the pull-up resistor select (PUR) register for this port
+    fn pull_up_select(&self) -> *mut u32 {
+        match self.port {
+            Port::A => registers::gpio::pur::PORT_A,
+            Port::F => registers::gpio::pur::PORT_F,
+            _ => todo!(),
+        }
+    }
+
+    // Note to self: page 1351 of data sheet for PWM
+    // Apparently also for ADC!
+}
+
+
+impl PortIO {
+    /// The corresponding bit for this port in system's run-mode clock gate control (RCGC) register
+    fn run_mode_clock_gate_control(&self) -> Bit {
+        match self.port {
+            Port::A => Bit::Zero,
+            Port::B => Bit::One,
+            Port::C => Bit::Two,
+            Port::D => Bit::Three,
+            Port::E => Bit::Four,
+            Port::F => Bit::Five,
+        }
+    }
+}
+
+impl PortIO {
+    pub fn setup_readable_pins<const N: usize>(
+        &self,
+        bits: &[Bit; N],
+        options: ReadablePinSetup,
+    ) -> ReadablePins<N> {
+        // Unlock the pins
+        unsafe {
+            memory::write(self.lock(), UNLOCK);
+
+            memory::set_bits(self.commit(), bits);
+        }
+
+        // Disable analog when it's not selected (and enable analog if it is)
+        match options.function {
+            Function::Analog => unsafe {
+                memory::set_bits(self.analog_mode_select(), bits);
+            },
+            _ => unsafe {
+                memory::clear_bits(self.analog_mode_select(), bits);
+            },
+        }
+
+        unsafe {
+            memory::clear_bits(self.direction(), bits);
+        }
+
+        // TODO: finish
+
+        let data_address = self.data();
+
+        let pins: [ReadablePin; N] = bits.map(|bit| ReadablePin { data_address, bit });
+
+        ReadablePins { data_address, pins }
+    }
+
+    pub fn setup_writable_pins<const N: usize>(
+        &self,
+        bits: &[Bit; N],
+        options: WritablePinSetup,
+    ) -> WritablePins<N> {
+        // Unlock the pins
+        unsafe {
+            memory::write(self.lock(), UNLOCK);
+
+            memory::set_bits(self.commit(), bits);
+        }
+
+        // Disable analog when it's not selected (and enable analog if it is)
+        match options.function {
+            Function::Analog => unsafe {
+                memory::set_bits(self.analog_mode_select(), bits);
+            },
+            _ => unsafe {
+                memory::clear_bits(self.analog_mode_select(), bits);
+            },
+        }
+
+        unsafe {
+            memory::set_bits(self.direction(), bits);
+        }
+
+        unsafe {
+            for bit in bits {
+                let memory_bits = [0; N];
+                let values = match options.function {
+                    Function::Analog => todo!(),
+                    Function::Digital => todo!(),
+                    Function::CAN => todo!(),
+                    Function::I2C => todo!(),
+                    Function::PWM => todo!(),
+                    Function::UART => todo!(),
+                };
+                memory::write_bits(self.port_control(), memory_bits, values);
+            }
+        }
+
+        // TODO: check page 671 or 682 (+ more prob) for a table showing initial pin states
+
+        // TODO: finish
+
+        let data_address = self.data();
+
+        let pins: [WritablePin; N] = bits.map(|bit| WritablePin { data_address, bit });
+
+        WritablePins { data_address, pins }
+    }
+}
+
+#[derive(Clone, Copy)]
+pub enum Bit {
+    Zero = 0,
+    One = 1,
+    Two = 2,
+    Three = 3,
+    Four = 4,
+    Five = 5,
+    Six = 6,
+    Seven = 7,
+}
+
+/// Page 1351 of data sheet
+pub enum Function {
+    Analog,
+    Digital,
+    CAN,
+    I2C,
+    PWM,
+    UART,
+}
+
+pub struct ReadablePinSetup {
+    pub function: Function,
+}
+pub struct ReadablePins<const N: usize> {
+    data_address: *mut u32,
+    pins: [ReadablePin; N],
+}
+impl<const N: usize> ReadablePins<N> {
+    pub fn pins(&self) -> [ReadablePin; N] {
+        self.pins
+    }
+
+    pub fn read_all(&self) -> [bool; N] {
+        unsafe { memory::read_bits(self.data_address, &self.pins.map(|pin| pin.bit)) }
+    }
+}
+#[derive(Clone, Copy)]
+pub struct ReadablePin {
+    data_address: *mut u32,
+    bit: Bit,
+}
+impl ReadablePin {
+    pub fn read(&self) -> bool {
+        let current = unsafe { memory::read(self.data_address) };
+        current & (1 << self.bit as u32) != 0
+    }
+}
+
+pub struct WritablePinSetup {
+    pub function: Function,
+}
+pub struct WritablePins<const N: usize> {
+    data_address: *mut u32,
+    pins: [WritablePin; N],
+}
+impl<const N: usize> WritablePins<N> {
+    pub fn pins(&self) -> [WritablePin; N] {
+        self.pins
+    }
+
+    pub fn read_all(&self) -> [bool; N] {
+        unsafe { memory::read_bits(self.data_address, &self.pins.map(|pin| pin.bit)) }
+    }
+    pub fn write_all(&mut self, values: [bool; N]) {
+        unsafe { memory::write_bits(self.data_address, &self.pins.map(|pin| pin.bit), values) }
+    }
+    pub fn update_all<Updater: Fn([bool; N]) -> [bool; N]>(&mut self, updater: Updater) {
+        self.write_all(updater(self.read_all()));
+    }
+
+    pub fn clear_all(&mut self) {
+        unsafe {
+            memory::clear_bits(self.data_address, &self.pins.map(|pin| pin.bit));
+        }
+    }
+    pub fn set_all(&mut self) {
+        unsafe {
+            memory::set_bits(self.data_address, &self.pins.map(|pin| pin.bit));
+        }
+    }
+    pub fn toggle_all(&mut self) {
+        unsafe {
+            memory::toggle_bits(self.data_address, &self.pins.map(|pin| pin.bit));
+        }
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct WritablePin {
+    data_address: *mut u32,
+    bit: Bit,
+}
+impl WritablePin {
+    pub fn read(&self) -> bool {
+        let current = unsafe { memory::read(self.data_address) };
+        current & (1 << self.bit as u32) != 0
+    }
+    pub fn clear(&mut self) {
+        unsafe {
+            memory::clear_bits(self.data_address, &[self.bit]);
+        }
+    }
+    pub fn set(&mut self) {
+        unsafe {
+            memory::set_bits(self.data_address, &[self.bit]);
+        }
+    }
+    pub fn toggle(&mut self) {
+        unsafe {
+            memory::toggle_bits(self.data_address, &[self.bit]);
+        }
+    }
+}
+
+pub fn setup_board() -> Board {
+    Board
+}

src/lib/registers.rs

@@ -0,0 +1,106 @@
+//! Memory addresses of registers
+//! Data sheet: https://www.ti.com/lit/ds/spms376e/spms376e.pdf
+
+// TODO: check page 92-94 for more features ("Memory Map" table)!
+
+// TODO: check page 1230 onward for PWM
+
+/// Modeled after page 660 of data sheet (GPIO Register Map)
+pub mod gpio {
+    mod base {
+        pub const PORT_A: u32 = 0x4000_4000;
+        pub const PORT_F: u32 = 0x4002_5000;
+    }
+
+    /// Page 671 of data sheet
+    pub mod afsel {
+        const OFFSET: u32 = 0x420;
+
+        pub const PORT_A: *mut u32 = (super::base::PORT_A + OFFSET) as *mut u32;
+        pub const PORT_F: *mut u32 = (super::base::PORT_F + OFFSET) as *mut u32;
+    }
+
+    /// Page 687 of data sheet
+    pub mod amsel {
+        const OFFSET: u32 = 0x52C;
+
+        pub const PORT_A: *mut u32 = (super::base::PORT_A + OFFSET) as *mut u32;
+        pub const PORT_F: *mut u32 = (super::base::PORT_F + OFFSET) as *mut u32;
+    }
+
+    /// Page 685 of data sheet
+    pub mod cr {
+        const OFFSET: u32 = 0x524;
+
+        pub const PORT_A: *mut u32 = (super::base::PORT_A + OFFSET) as *mut u32;
+        pub const PORT_F: *mut u32 = (super::base::PORT_F + OFFSET) as *mut u32;
+    }
+
+    /// Page 662 of data sheet
+    pub mod data {
+        const OFFSET: u32 = 0x000;
+
+        pub const PORT_A: *mut u32 = (super::base::PORT_A + OFFSET) as *mut u32;
+        pub const PORT_F: *mut u32 = (super::base::PORT_F + OFFSET) as *mut u32;
+    }
+
+    /// Page 682 of data sheet
+    pub mod den {
+        const OFFSET: u32 = 0x51C;
+
+        pub const PORT_A: *mut u32 = (super::base::PORT_A + OFFSET) as *mut u32;
+        pub const PORT_F: *mut u32 = (super::base::PORT_F + OFFSET) as *mut u32;
+    }
+
+    /// Page 663 of data sheet
+    pub mod dir {
+        const OFFSET: u32 = 0x400;
+
+        pub const PORT_A: *mut u32 = (super::base::PORT_A + OFFSET) as *mut u32;
+        pub const PORT_F: *mut u32 = (super::base::PORT_F + OFFSET) as *mut u32;
+    }
+
+    /// Page 684 of data sheet
+    pub mod lock {
+        const OFFSET: u32 = 0x520;
+
+        pub const PORT_A: *mut u32 = (super::base::PORT_A + OFFSET) as *mut u32;
+        pub const PORT_F: *mut u32 = (super::base::PORT_F + OFFSET) as *mut u32;
+    }
+
+    /// Page 688 of data sheet
+    pub mod pctl {
+        const OFFSET: u32 = 0x52C;
+
+        pub const PORT_A: *mut u32 = (super::base::PORT_A + OFFSET) as *mut u32;
+        pub const PORT_F: *mut u32 = (super::base::PORT_F + OFFSET) as *mut u32;
+    }
+
+    /// Page 679 of data sheet
+    pub mod pdr {
+        const OFFSET: u32 = 0x514;
+
+        pub const PORT_A: *mut u32 = (super::base::PORT_A + OFFSET) as *mut u32;
+        pub const PORT_F: *mut u32 = (super::base::PORT_F + OFFSET) as *mut u32;
+    }
+
+    /// Page 677 of data sheet
+    pub mod pur {
+        const OFFSET: u32 = 0x510;
+
+        pub const PORT_A: *mut u32 = (super::base::PORT_A + OFFSET) as *mut u32;
+        pub const PORT_F: *mut u32 = (super::base::PORT_F + OFFSET) as *mut u32;
+    }
+
+    // TODO: examine page 670 for when (if) I do interrupts
+}
+
+// TODO: examine page 690 (ADC) for applicability
+
+/// Page 231 of data sheet
+pub mod system {
+    const BASE: u32 = 0x400F_E000;
+
+    // TODO: page 340
+    pub const RCGCGPIO: *mut u32 = (BASE + 0x608) as *mut u32;
+}

src/main.rs

@@ -6,6 +6,8 @@ use core::ptr;
 use panic_halt as _; // you can put a breakpoint on `rust_begin_unwind` to catch panics
 
 use cortex_m_rt::entry;
+use test_cortex_m4_rust::{Function, Bit, ReadablePinSetup, WritablePinSetup, PortSetup, Port, setup_board, H, L};
+// use test_cortex_m4_rust::setup_board;
 
 // Begin .h file contents
 
@@ -15,9 +17,9 @@ const GPIO_PORTF_DIR_R: *mut u32 = 0x40025400 as *mut u32;
 const GPIO_PORTF_AFSEL_R: *mut u32 = 0x40025420 as *mut u32;
 const GPIO_PORTF_PUR_R: *mut u32 = 0x40025510 as *mut u32;
 const GPIO_PORTF_DEN_R: *mut u32 = 0x4002551C as *mut u32;
-const GPIO_PORTF_LOCK_R: *mut u32 = 0x40025520 as *mut u32;
-const GPIO_PORTF_CR_R: *mut u32 = 0x40025524 as *mut u32;
-const GPIO_PORTF_AMSEL_R: *mut u32 = 0x40025528 as *mut u32;
+const GPIOLOCK_PORT_F: *mut u32 = 0x40025520 as *mut u32;
+const GPIOCR_PORT_F: *mut u32 = 0x40025524 as *mut u32;
+const GPIOAMSEL_PORT_F: *mut u32 = 0x40025528 as *mut u32;
 const GPIO_PORTF_PCTL_R: *mut u32 = 0x4002552C as *mut u32;
 
 const SYSCTL_RCGCPIO_R: *mut u32 = 0x400FE608 as *mut u32;
@@ -41,26 +43,26 @@ const BLUE: u8 = 0b0000_0100;
 
 fn setup_port_f() {
     // 1) activate clock for Port F
-    unsafe {
-        ptr::write_volatile(
-            SYSCTL_RCGCPIO_R,
-            ptr::read_volatile(SYSCTL_RCGCPIO_R) | 0x00_00_00_20,
-        );
-    }
+    // unsafe {
+    //     ptr::write_volatile(
+    //         SYSCTL_RCGCPIO_R,
+    //         ptr::read_volatile(SYSCTL_RCGCPIO_R) | 0x00_00_00_20,
+    //     );
+    // }
 
     // Delay
-    for _ in 0u8..2u8 {}
+    // for _ in 0u8..2u8 {}
 
     // 2) unlock GPIO Port F
-    unsafe {
-        ptr::write_volatile(GPIO_PORTF_LOCK_R, 0x4C4F434B);
-        // allow changes to PF4-0
-        // only PF0 needs to be unlocked, other bits can't be locked
-        ptr::write_volatile(GPIO_PORTF_CR_R, 0b0001_1111);
-    }
+    // unsafe {
+    //     ptr::write_volatile(GPIOLOCK_PORT_F, 0x4C4F434B);
+    //     // allow changes to PF4-0
+    //     // only PF0 needs to be unlocked, other bits can't be locked
+    //     ptr::write_volatile(GPIOCR_PORT_F, 0b0001_1111);
+    // }
 
     // 3) disable analog on PF
-    unsafe { ptr::write_volatile(GPIO_PORTF_AMSEL_R, 0x00) }
+    // unsafe { ptr::write_volatile(GPIOAMSEL_PORT_F, 0x00) }
 
     // 4) PCTL GPIO on PF4-0
     unsafe {
@@ -68,9 +70,9 @@ fn setup_port_f() {
     }
 
     // 5) PF4,PF0 in, PF3-1 out
-    unsafe {
-        ptr::write_volatile(GPIO_PORTF_DIR_R, 0x0E);
-    }
+    // unsafe {
+    //     ptr::write_volatile(GPIO_PORTF_DIR_R, 0x0E);
+    // }
     // 6) disable alt funct on PF7-0
     unsafe {
         ptr::write_volatile(GPIO_PORTF_AFSEL_R, 0x00);
@@ -97,6 +99,26 @@ fn output_to_port_f(value: u8) {
     }
 }
 
+// #[entry]
+// fn main() -> ! {
+//     let board = setup_board();
+//     let port_f = board.setup_gpio_port(Port::F, PortSetup);
+
+//     let switches = port_f.setup_readable_pins([Bit::Zero, Bit::Four], ReadablePinSetup);
+//     let [sw1, sw2] = switches.pins();
+
+//     let mut rgb_led = port_f.setup_writable_pins(&[Bit::One, Bit::Three, Bit::Two], WritablePinSetup { drive: PinDrive::Digital });
+
+//     loop {
+//         match switches.read_all() {
+//             [L, L] => rgb_led.write_all([L, H, L]),
+//             [L, H] => rgb_led.write_all([L, L, H]),
+//             [H, L] => rgb_led.write_all([L, H, L]),
+//             [H, H] => rgb_led.write_all([L, L, L]),
+//         }
+//     }
+// }
+
 #[entry]
 fn main() -> ! {
     setup_port_f();
@@ -105,12 +127,14 @@ fn main() -> ! {
         let status = input_from_port_f();
 
         match status {
-            0x01 => output_to_port_f(BLUE),
-            0x10 => output_to_port_f(RED),
-            0x00 => output_to_port_f(GREEN),
+            0x00 => output_to_port_f(RED | GREEN),
+            0x01 => output_to_port_f(RED),
+            0x10 => output_to_port_f(GREEN),
             0x11 => output_to_port_f(BLACK),
             // Impossible case
-            _ => output_to_port_f(RED | BLUE),
+            _ => output_to_port_f(BLUE),
         }
     }
 }
+
+// TODO: implement an extremely simple example of the task system (using a timer trigger) that is a traffic light (green -> yellow -> red -> green...)