1use core::marker::PhantomData;
2
3#[derive(Copy, Clone, PartialEq, Eq)]
4pub struct RW;
5#[derive(Copy, Clone, PartialEq, Eq)]
6pub struct R;
7#[derive(Copy, Clone, PartialEq, Eq)]
8pub struct W;
9
10mod sealed {
11 use super::*;
12 pub trait Access {}
13 impl Access for R {}
14 impl Access for W {}
15 impl Access for RW {}
16}
17
18pub trait Access: sealed::Access + Copy {}
19impl Access for R {}
20impl Access for W {}
21impl Access for RW {}
22
23pub trait Read: Access {}
24impl Read for RW {}
25impl Read for R {}
26
27pub trait Write: Access {}
28impl Write for RW {}
29impl Write for W {}
30
31#[derive(Copy, Clone, PartialEq, Eq)]
32pub struct Reg<T: Copy, A: Access> {
33 ptr: *mut u8,
34 phantom: PhantomData<*mut (T, A)>,
35}
36unsafe impl<T: Copy, A: Access> Send for Reg<T, A> {}
37unsafe impl<T: Copy, A: Access> Sync for Reg<T, A> {}
38
39impl<T: Copy, A: Access> Reg<T, A> {
40 #[allow(clippy::missing_safety_doc)]
41 #[inline(always)]
42 pub const unsafe fn from_ptr(ptr: *mut T) -> Self {
43 Self {
44 ptr: ptr as _,
45 phantom: PhantomData,
46 }
47 }
48
49 #[inline(always)]
50 pub const fn as_ptr(&self) -> *mut T {
51 self.ptr as _
52 }
53}
54
55impl<T: Copy, A: Read> Reg<T, A> {
56 #[inline(always)]
57 pub fn read(&self) -> T {
58 unsafe { (self.ptr as *mut T).read_volatile() }
59 }
60}
61
62impl<T: Copy, A: Write> Reg<T, A> {
63 #[inline(always)]
64 pub fn write_value(&self, val: T) {
65 unsafe { (self.ptr as *mut T).write_volatile(val) }
66 }
67}
68
69impl<T: Default + Copy, A: Write> Reg<T, A> {
70 #[inline(always)]
71 pub fn write<R>(&self, f: impl FnOnce(&mut T) -> R) -> R {
72 let mut val: T = Default::default();
73 let res: R = f(&mut val);
74 self.write_value(val);
75 res
76 }
77}
78
79impl<T: Copy, A: Read + Write> Reg<T, A> {
80 #[inline(always)]
81 pub fn modify<R>(&self, f: impl FnOnce(&mut T) -> R) -> R {
82 let mut val: T = self.read();
83 let res: R = f(&mut val);
84 self.write_value(val);
85 res
86 }
87}
88