blob: 465462b9bc854e1dcc54ec5b6777a27284f87451 (
plain)
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
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
|
// SPDX-License-Identifier: GPL-2.0
//! Common clock framework.
//!
//! C header: [`include/linux/clk.h`](../../../../include/linux/clk.h)
use crate::{bindings, error::Result, to_result};
use core::mem::ManuallyDrop;
/// Represents `struct clk *`.
///
/// # Invariants
///
/// The pointer is valid.
pub struct Clk(*mut bindings::clk);
impl Clk {
/// Creates new clock structure from a raw pointer.
///
/// # Safety
///
/// The pointer must be valid.
pub unsafe fn new(clk: *mut bindings::clk) -> Self {
Self(clk)
}
/// Returns value of the rate field of `struct clk`.
pub fn get_rate(&self) -> usize {
// SAFETY: The pointer is valid by the type invariant.
unsafe { bindings::clk_get_rate(self.0) as usize }
}
/// Prepares and enables the underlying hardware clock.
///
/// This function should not be called in atomic context.
pub fn prepare_enable(self) -> Result<EnabledClk> {
// SAFETY: The pointer is valid by the type invariant.
to_result(|| unsafe { bindings::clk_prepare_enable(self.0) })?;
Ok(EnabledClk(self))
}
}
impl Drop for Clk {
fn drop(&mut self) {
// SAFETY: The pointer is valid by the type invariant.
unsafe { bindings::clk_put(self.0) };
}
}
// SAFETY: `Clk` is not restricted to a single thread so it is safe
// to move it between threads.
unsafe impl Send for Clk {}
/// A clock variant that is prepared and enabled.
pub struct EnabledClk(Clk);
impl EnabledClk {
/// Returns value of the rate field of `struct clk`.
pub fn get_rate(&self) -> usize {
self.0.get_rate()
}
/// Disables and later unprepares the underlying hardware clock prematurely.
///
/// This function should not be called in atomic context.
pub fn disable_unprepare(self) -> Clk {
let mut clk = ManuallyDrop::new(self);
// SAFETY: The pointer is valid by the type invariant.
unsafe { bindings::clk_disable_unprepare(clk.0 .0) };
core::mem::replace(&mut clk.0, Clk(core::ptr::null_mut()))
}
}
impl Drop for EnabledClk {
fn drop(&mut self) {
// SAFETY: The pointer is valid by the type invariant.
unsafe { bindings::clk_disable_unprepare(self.0 .0) };
}
}
|