use core::marker::PhantomData;
#[derive(Copy, Clone, PartialEq, Eq)]
pub struct RW;
#[derive(Copy, Clone, PartialEq, Eq)]
pub struct R;
#[derive(Copy, Clone, PartialEq, Eq)]
pub struct W;
mod sealed;
pub trait Access: sealed::Access + Copy {}
impl Access for R {}
impl Access for W {}
impl Access for RW {}
pub trait Read: Access {}
impl Read for RW {}
impl Read for R {}
pub trait Write: Access {}
impl Write for RW {}
impl Write for W {}
#[derive(Copy, Clone, PartialEq, Eq)]
pub struct Reg<T: Copy, A: Access> {
ptr: *mut u8,
phantom: PhantomData<*mut (T, A)>,
}
unsafe impl<T: Copy, A: Access> Send for Reg<T, A> {}
unsafe impl<T: Copy, A: Access> Sync for Reg<T, A> {}
impl<T: Copy, A: Access> Reg<T, A> {
#[inline(always)]
pub const unsafe fn from_ptr(ptr: *mut T) -> Self {
Self {
ptr: ptr as _,
phantom: PhantomData,
}
}
#[inline(always)]
pub const fn as_ptr(&self) -> *mut T {
self.ptr as _
}
}
impl<T: Copy, A: Read> Reg<T, A> {
#[inline(always)]
pub fn read(&self) -> T {
unsafe { (self.ptr as *mut T).read_volatile() }
}
}
impl<T: Copy, A: Write> Reg<T, A> {
#[inline(always)]
pub fn write_value(&self, val: T) {
unsafe { (self.ptr as *mut T).write_volatile(val) }
}
}
impl<T: Default + Copy, A: Write> Reg<T, A> {
#[inline(always)]
pub fn write<R>(&self, f: impl FnOnce(&mut T) -> R) -> R {
let mut val = Default::default();
let res = f(&mut val);
self.write_value(val);
res
}
}
impl<T: Copy, A: Read + Write> Reg<T, A> {
#[inline(always)]
pub fn modify<R>(&self, f: impl FnOnce(&mut T) -> R) -> R {
let mut val = self.read();
let res = f(&mut val);
self.write_value(val);
res
}
}