Start implementing LCD driver

src/bsp/aarch64/time.rs

@@ -3,8 +3,8 @@
 use core::arch::asm;
 use core::time::Duration;
 
-use crate::traits::time::TimeManager;
 use crate::println;
+use crate::traits::time::TimeManager;
 
 const NS_PER_S: u64 = 1_000_000_000;
 const CNTP_CTL_EL0_ENABLE_MASK: u64 = 0b001;

src/bsp/generic_gpio_drivers/lcd.rs

@@ -0,0 +1,141 @@
+//! Driver for LiquidCrystal Displays plugs to the GPIO of the board.
+//! The LCD need to be an Hitachi HD44780 chipset compatible.
+//!
+//! This driver inspired from the one from the arduino libriaries
+//! (https://github.com/arduino-libraries/LiquidCrystal) and the
+//! documentation from wikipedia (https://en.wikipedia.org/wiki/Hitachi_HD44780_LCD_controller)
+
+use crate::gpio;
+
+// TODO: change USIZE to a Pin struct (and implement the Pin struct :'( )
+/// The structure handling the LCD periferic
+pub struct Lcd {
+    /// The Register Select pinout.
+    rs_pin: usize,
+    /// The Read/Write pinout.
+    ///
+    /// If set to None, assumes the rw pin of the lcd is connected to the ground (write state)
+    rw_pin: Option<usize>,
+    /// The Enable pinout.
+    ///
+    /// TODO: wiki says falling-edge triggered, arduino comment says activated by a HIGH pulse.
+    e_pin: usize,
+    /// First 4 data bits pins.
+    ///
+    /// Set to None if the lcd is in 4-bit mode.
+    first_data_bits_pins: Option<[usize; 4]>,
+    /// Last 4 data bits pins.
+    last_data_bits_pins: [usize; 4],
+    /// The number of line of the LCD.
+    nb_lines: usize,
+    /// The number of row of the LCD.
+    nb_rows: usize,
+    /// Weither or not the LCD has been initialized in the rigth state.
+    initialized: bool,
+}
+
+impl Lcd {
+    /// Instanciate a [`Lcd`] object in 4 bits mode.
+    pub const fn new_4bits_mode(
+        rs_pin: usize,
+        rw_pin: Option<usize>,
+        e_pin: usize,
+        db4: usize,
+        db5: usize,
+        db6: usize,
+        db7: usize,
+        nb_lines: usize,
+        nb_rows: usize,
+    ) -> Self {
+        Self {
+            rs_pin,
+            rw_pin,
+            e_pin,
+            first_data_bits_pins: None,
+            last_data_bits_pins: [db4, db5, db6, db7],
+            nb_lines,
+            nb_rows,
+            initialized: false,
+        }
+    }
+
+    /// Instanciate a [`Lcd`] object in 8 bits mode.
+    pub const fn new_8bits_mode(
+        rs_pin: usize,
+        rw_pin: Option<usize>,
+        e_pin: usize,
+        db0: usize,
+        db1: usize,
+        db2: usize,
+        db3: usize,
+        db4: usize,
+        db5: usize,
+        db6: usize,
+        db7: usize,
+        nb_lines: usize,
+        nb_rows: usize,
+    ) -> Self {
+        Self {
+            rs_pin,
+            rw_pin,
+            e_pin,
+            first_data_bits_pins: Some([db0, db1, db2, db3]),
+            last_data_bits_pins: [db4, db5, db6, db7],
+            nb_lines,
+            nb_rows,
+            initialized: false,
+        }
+    }
+
+    /// Initialize the LCD.
+    pub fn init(&mut self) -> Result::<(), &str> {
+        gpio::set_pin_fonction(self.rs_pin, gpio::PinFunction::Output)?;
+        gpio::set_pin_output_state(self.rs_pin, gpio::PinOutputState::Low)?;
+        if let Some(rw_pin) = self.rw_pin {
+            gpio::set_pin_fonction(rw_pin, gpio::PinFunction::Output)?;
+            gpio::set_pin_output_state(rw_pin, gpio::PinOutputState::Low)?;
+        }
+        gpio::set_pin_fonction(self.e_pin, gpio::PinFunction::Output)?;
+        gpio::set_pin_output_state(self.e_pin, gpio::PinOutputState::Low)?;
+        if let Some(first_data_bits_pins) = self.first_data_bits_pins {
+            for pin in first_data_bits_pins.into_iter() {
+                gpio::set_pin_fonction(pin, gpio::PinFunction::Output)?;
+            }
+        }
+        for pin in self.last_data_bits_pins.into_iter() {
+            gpio::set_pin_fonction(pin, gpio::PinFunction::Output)?;
+        }
+
+        // TODO: send 0b0011 3 times to make sure to be in 8bits mode 5x8 characters
+        // TODO: set the new mode with Function set (2 times if 4 bits modes, 1 to set DL=0,
+        //     then the actual one)
+        self.initialized = true;
+        todo!();
+    }
+
+    /// Send an 'enable' signal.
+    fn enable(&self) {
+        todo!()
+    }
+
+    /// Send a Function Set instruction.
+    fn function_set(&self) {
+        todo!()
+    }
+
+    /// Send data to the lcd.
+    fn send_data(&self) {
+        todo!()
+    }
+
+    /// Send 8 bits of data.
+    fn send_8bit(&self) {
+        todo!()
+    }
+
+    /// Send 4 bits of data.
+    fn send_4bits(&self) {
+        // TODO: type?
+        todo!()
+    }
+}

src/bsp/generic_gpio_drivers/mod.rs

@@ -0,0 +1,3 @@
+//! Generic driver for perifierics to plug to the GPIO.
+
+pub mod lcd;

src/bsp/mod.rs

@@ -9,3 +9,6 @@ pub mod rpi4;
 
 #[cfg(target_arch = "aarch64")]
 pub mod aarch64;
+
+// TODO: only for bsp with support for GPIO
+pub mod generic_gpio_drivers;

src/bsp/rpi3/gpio.rs

@@ -71,7 +71,9 @@ pub fn set_pin_fonction(n: usize, function: PinFunction) -> Result<(), &'static
     let mut val = unsafe { core::ptr::read_volatile(address as *mut u32) };
     val &= !field.get_mask();
     val |= Into::<u32>::into(function) << field.get_offset();
-    unsafe { core::ptr::write_volatile(address as *mut u32, val); }
+    unsafe {
+        core::ptr::write_volatile(address as *mut u32, val);
+    }
     Ok(())
 }
 
@@ -92,6 +94,8 @@ pub fn set_pin_output_state(n: usize, state: PinOutputState) -> Result<(), &'sta
     let val = field.get_mask();
     let address = field.get_address();
     // 0 has no effect on this field: no nead to read-modify-write
-    unsafe { core::ptr::write_volatile(address as *mut u32, val); }
+    unsafe {
+        core::ptr::write_volatile(address as *mut u32, val);
+    }
     Ok(())
 }

src/bsp/rpi3/memory_map.rs

@@ -2,7 +2,6 @@
 
 use crate::utils::field::Field;
 
-
 pub const START_PHYSICAL_ADDRESS: usize = 0x3F00_0000;
 
 // ** GPIO addresses **
@@ -300,7 +299,6 @@ pub mod uart {
         /// Field located inside the Data Register [`dr`].
         pub dr_data: Field,
 
-
         /// Receive Status Register/Error Clear Register, 32 bits long.
         ///
         /// # Bits distribution:
@@ -658,7 +656,6 @@ pub mod uart {
         pub cr_uarten: Field,
 
         // TODO: Finish detailling the registers
-
         /// Interrupt FIFO Level Select register, 32 bits long.
         ///
         /// # Bits distribution:
@@ -809,7 +806,6 @@ pub mod uart {
         /// - 31-11: reserved. Write as 0, value read don't have meaning, R.
         /// - 10-0: TDR10_0. When ITCRI1 is set to 1, data read an write directly from the FIFOs, R/W.
         pub tdr: Field,
-        
     }
 
     impl UartMemoryMap {
@@ -878,5 +874,4 @@ pub mod uart {
     }
 
     pub const UART: UartMemoryMap = UartMemoryMap::new(UART_START);
-
 }

src/bsp/rpi3/uart.rs

@@ -20,7 +20,10 @@ pub struct UartInner<'a> {
 impl<'a> UartInner<'a> {
     /// Constructor for [`Uart`].
     const fn new(memory_map: &'a mm::UartMemoryMap) -> Self {
-        Self { initialized: false, memory_map }
+        Self {
+            initialized: false,
+            memory_map,
+        }
     }
 
     /// Initialise the UART.
@@ -153,14 +156,11 @@ impl Read for Uart<'_> {
 }
 
 impl<'a> Uart<'a> {
-
     // TODO: not sure this should be public? public in bsp only?
     /// Create a new UART object
     const fn new(memory_map: &'a mm::UartMemoryMap) -> Self {
         Self {
-            inner: DummyMutex::new(
-                UartInner::new(memory_map)
-            )
+            inner: DummyMutex::new(UartInner::new(memory_map)),
         }
     }
 

src/bsp/rpi4/memory_map.rs

@@ -12,4 +12,3 @@ pub const UART2_START: usize = START_LOW_PERIPHERAL_MODE + 0x0020_1400;
 pub const UART3_START: usize = START_LOW_PERIPHERAL_MODE + 0x0020_1600;
 pub const UART4_START: usize = START_LOW_PERIPHERAL_MODE + 0x0020_1800;
 pub const UART5_START: usize = START_LOW_PERIPHERAL_MODE + 0x0020_1A00;
-

src/main.rs

@@ -9,35 +9,35 @@
 #![cfg_attr(not(test), no_std)]
 #![feature(format_args_nl)]
 #![feature(panic_info_message)]
-
 #![allow(dead_code)]
 
-mod traits;
 mod bsp;
+mod traits;
 mod utils;
 
+#[cfg(not(test))]
+mod log;
 #[cfg(not(test))]
 mod panic;
 #[cfg(not(test))]
 mod print;
-#[cfg(not(test))]
-mod log;
 
-#[cfg(not(test))]
-use core::arch::global_asm;
 #[cfg(not(test))]
 use core::arch::asm;
+#[cfg(not(test))]
+use core::arch::global_asm;
 
 use core::time::Duration;
 
 // TODO: handle this with features
 #[cfg(not(test))]
-use crate::bsp::rpi3::uart::console;
+use crate::bsp::aarch64::time::time_manager;
 #[cfg(not(test))]
 use crate::bsp::rpi3::gpio;
 #[cfg(not(test))]
-use crate::bsp::aarch64::time::time_manager;
+use crate::bsp::rpi3::uart::console;
 
+use crate::bsp::generic_gpio_drivers::lcd::Lcd;
 use crate::traits::time::TimeManager;
 
 // TODO: move this to BSP
@@ -46,7 +46,9 @@ use crate::traits::time::TimeManager;
 #[inline(always)]
 pub fn wait_forever() -> ! {
     loop {
-        unsafe { asm!("wfe"); }
+        unsafe {
+            asm!("wfe");
+        }
     }
 }
 
@@ -58,7 +60,6 @@ global_asm!(include_str!("boot.s"));
 #[cfg(not(test))]
 #[no_mangle]
 pub unsafe fn _start_rust() -> ! {
-
     // Set TX and RX function for pin 14 and 15
     match gpio::set_pin_fonction(14, gpio::PinFunction::AltFunc0) {
         _ => (),
@@ -82,6 +83,9 @@ pub unsafe fn _start_rust() -> ! {
     error!("error");
     fatal!("fatal");
 
+    let mut lcd = Lcd::new_8bits_mode(1, Some(2), 3, 4, 5, 6, 7, 8, 9, 10, 11, 1, 80);
+    let _ = lcd.init();
+
     let mut buffer = ['X'; 200];
     let mut i = 0;
     let mut c = console().read_char();

src/panic.rs

@@ -36,7 +36,9 @@ fn panic(info: &PanicInfo) -> ! {
         "Kernel panic!\n\n\
         Panic location:\n    File: '{}', line {}, column {}\n\n\
         {}",
-        location, line, column,
+        location,
+        line,
+        column,
         info.message().unwrap_or(&format_args!(""))
     );
     wait_forever()

src/traits/console.rs

@@ -27,7 +27,6 @@ pub trait Read {
     fn flush_input(&self);
 }
 
-
 /// A Dummy Console.
 ///
 /// The DummyConsole implement the [`Console`] trait, and do nothing.
@@ -51,5 +50,4 @@ impl Read for DummyConsole {
     fn flush_input(&self) {}
 }
 
-
 impl Console for DummyConsole {}

src/traits/time.rs

@@ -3,7 +3,6 @@
 use core::time::Duration;
 
 pub trait TimeManager {
-
     /// Return the clock frequency, meaning the resolution of the
     /// time mesurement.
     fn frequency(&self) -> u64;

src/utils/field.rs

@@ -24,7 +24,7 @@ pub struct Field {
     /// The size of the field in bit.
     size: usize,
     /// The mask for the field in the `u32` at `address`.
-    mask: u32
+    mask: u32,
 }
 
 impl Field {
@@ -45,7 +45,12 @@ impl Field {
 
         let mask = Self::compute_mask(offset, size);
 
-        Self { address, offset, size, mask }
+        Self {
+            address,
+            offset,
+            size,
+            mask,
+        }
     }
 
     /// Compute mask for the field.
@@ -86,7 +91,11 @@ impl Field {
     /// Set the value of the field in the provided u32.
     #[inline]
     pub fn read_and_write_to_u32(&self, val: u32, register: u32) -> u32 {
-        assert_eq!(val & !(self.mask >> self.offset), 0, "Value greater than the field");
+        assert_eq!(
+            val & !(self.mask >> self.offset),
+            0,
+            "Value greater than the field"
+        );
         register & !self.mask | (val << self.offset)
     }
 
@@ -124,26 +133,17 @@ mod test {
     #[test]
     fn test_get_address() {
         // Test when the address is alligned
-        assert_eq!(
-            Field::new(0x1234_5678, 0, 1).get_address(),
-            0x1234_5678,
-        );
+        assert_eq!(Field::new(0x1234_5678, 0, 1).get_address(), 0x1234_5678,);
     }
 
     #[test]
     fn test_get_offset() {
-        assert_eq!(
-            Field::new(0x1234_5678, 18, 1).get_offset(),
-            18,
-        );
+        assert_eq!(Field::new(0x1234_5678, 18, 1).get_offset(), 18,);
     }
 
     #[test]
     fn test_get_size() {
-        assert_eq!(
-            Field::new(0x1234_5678, 18, 1).get_size(),
-            1,
-        );
+        assert_eq!(Field::new(0x1234_5678, 18, 1).get_size(), 1,);
     }
 
     #[test]
@@ -188,32 +188,17 @@ mod test {
 
     #[test]
     fn test_get_mask() {
-        assert_eq!(
-            Field::new(0, 0, 1).get_mask(),
-            0b0000_0001,
-        );
-        assert_eq!(
-            Field::new(0, 0, 3).get_mask(),
-            0b0000_0111,
-        );
-        assert_eq!(
-            Field::new(0, 4, 1).get_mask(),
-            0b0001_0000,
-        );
-        assert_eq!(
-            Field::new(0, 4, 3).get_mask(),
-            0b0111_0000,
-        );
+        assert_eq!(Field::new(0, 0, 1).get_mask(), 0b0000_0001,);
+        assert_eq!(Field::new(0, 0, 3).get_mask(), 0b0000_0111,);
+        assert_eq!(Field::new(0, 4, 1).get_mask(), 0b0001_0000,);
+        assert_eq!(Field::new(0, 4, 3).get_mask(), 0b0111_0000,);
     }
 
     #[test]
     fn test_read_and_write_to_u32() {
         let field = Field::new(0, 3, 4);
         let val = 0b0101_0101;
-        assert_eq!(
-            field.read_and_write_to_u32(0b0101, val),
-            0b0010_1101,
-        );
+        assert_eq!(field.read_and_write_to_u32(0b0101, val), 0b0010_1101,);
     }
 
     #[test]
@@ -227,9 +212,6 @@ mod test {
     fn test_read_from_u32() {
         let field = Field::new(0, 3, 4);
         let val = 0b1100_1111;
-        assert_eq!(
-            field.read_from_u32(val),
-            0b1001,
-        );
+        assert_eq!(field.read_from_u32(val), 0b1001,);
     }
 }