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use crate::IO_BASE;
use volatile::{ReadOnly, Volatile};
const INT_BASE: usize = IO_BASE + 0xB000 + 0x200;
/// Allowed interrupts (ref: peripherals 7.5, page 113)
#[repr(u8)]
#[derive(Copy, Clone, PartialEq, Debug)]
pub enum Interrupt {
Timer1 = 1,
Timer3 = 3,
Usb = 9,
Aux = 29,
Gpio0 = 49,
Gpio1 = 50,
Gpio2 = 51,
Gpio3 = 52,
Uart = 57,
}
/// Interrupts registers starting from `INT_BASE` (ref: peripherals 7.5, page 112)
#[repr(C)]
#[allow(non_snake_case)]
struct Registers {
IRQBasicPending: ReadOnly<u32>,
IRQPending: [ReadOnly<u32>; 2],
FIQControl: Volatile<u32>,
EnableIRQ: [Volatile<u32>; 2],
EnableBasicIRQ: Volatile<u32>,
DisableIRQ: [Volatile<u32>; 2],
DisableBasicIRQ: Volatile<u32>,
}
/// Pending interrupts
pub struct PendingInterrupts(u64);
impl Iterator for PendingInterrupts {
type Item = usize;
#[inline]
fn next(&mut self) -> Option<Self::Item> {
let int = self.0.trailing_zeros();
if int < 64 {
self.0 &= !(1 << int);
Some(int as usize)
} else {
None
}
}
}
/// An interrupt controller. Used to enable and disable interrupts as well as to
/// check if an interrupt is pending.
pub struct Controller {
registers: &'static mut Registers,
}
impl Controller {
/// Returns a new handle to the interrupt controller.
#[inline]
pub fn new() -> Controller {
Controller {
registers: unsafe { &mut *(INT_BASE as *mut Registers) },
}
}
/// Enables the interrupt `int`.
pub fn enable(&mut self, int: Interrupt) {
self.registers.EnableIRQ[int as usize / 32].write(1 << (int as usize) % 32);
}
/// Disables the interrupt `int`.
pub fn disable(&mut self, int: Interrupt) {
self.registers.DisableIRQ[int as usize / 32].write(1 << (int as usize) % 32);
}
/// Returns `true` if `int` is pending. Otherwise, returns `false`.
pub fn is_pending(&self, int: Interrupt) -> bool {
self.registers.IRQPending[int as usize / 32].read() & (1 << (int as usize) % 32) != 0
}
/// Return all pending interrupts.
pub fn pending_interrupts(&self) -> PendingInterrupts {
let irq1 = self.registers.IRQPending[0].read() as u64;
let irq2 = self.registers.IRQPending[1].read() as u64;
PendingInterrupts((irq2 << 32) | irq1)
}
}