mmio-rs 0.2.0

Zero-overhead, no_std memory-mapped I/O register abstraction
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60

use crate::access::{Readable, Writeable};
use crate::irq_guard::critical_section;
use crate::register::Register;

/// Wraps a [`Register`] to provide interrupt-safe read-modify-write operations
/// via the [`critical_section`] mechanism.
pub struct AtomicRegister<'a, T: Copy, Access> {
    reg: &'a Register<T, Access>,
}

impl<'a, T, Access> AtomicRegister<'a, T, Access>
where
    T: Copy
        + core::ops::BitOr<Output = T>
        + core::ops::BitAnd<Output = T>
        + core::ops::BitXor<Output = T>
        + core::ops::Not<Output = T>,
    Access: Readable + Writeable,
{
    /// Creates an `AtomicRegister` wrapping `reg`.
    pub fn new(reg: &'a Register<T, Access>) -> Self {
        Self { reg }
    }

    /// Sets every bit that is 1 in `mask`, inside a critical section.
    #[inline(always)]
    pub fn set_bits(&self, mask: T) {
        critical_section(|| {
            let val = self.reg.read();
            self.reg.write(val | mask);
        });
    }

    /// Clears every bit that is 1 in `mask`, inside a critical section.
    #[inline(always)]
    pub fn clear_bits(&self, mask: T) {
        critical_section(|| {
            let val = self.reg.read();
            self.reg.write(val & !mask);
        });
    }

    /// Toggles every bit that is 1 in `mask`, inside a critical section.
    #[inline(always)]
    pub fn toggle_bits(&self, mask: T) {
        critical_section(|| {
            let val = self.reg.read();
            self.reg.write(val ^ mask);
        });
    }

    /// Reads the register, applies `f`, and writes the result back — all inside a critical section.
    #[inline(always)]
    pub fn modify<F: FnOnce(T) -> T>(&self, f: F) {
        critical_section(|| {
            let val = self.reg.read();
            self.reg.write(f(val));
        });
    }
}