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1// SPDX-License-Identifier: GPL-2.0
2// SPDX-FileCopyrightText: Copyright 2025 Collabora ltd.
3
4use crate::bindings;
5use crate::prelude::*;
6
7/// Flags to be used when registering IRQ handlers.
8///
9/// Flags can be used to request specific behaviors when registering an IRQ
10/// handler, and can be combined using the `|`, `&`, and `!` operators to
11/// further control the system's behavior.
12///
13/// A common use case is to register a shared interrupt, as sharing the line
14/// between devices is increasingly common in modern systems and is even
15/// required for some buses. This requires setting [`Flags::SHARED`] when
16/// requesting the interrupt. Other use cases include setting the trigger type
17/// through `Flags::TRIGGER_*`, which determines when the interrupt fires, or
18/// controlling whether the interrupt is masked after the handler runs by using
19/// [`Flags::ONESHOT`].
20///
21/// If an invalid combination of flags is provided, the system will refuse to
22/// register the handler, and lower layers will enforce certain flags when
23/// necessary. This means, for example, that all the
24/// [`crate::irq::Registration`] for a shared interrupt have to agree on
25/// [`Flags::SHARED`] and on the same trigger type, if set.
26#[derive(Clone, Copy, PartialEq, Eq)]
27pub struct Flags(c_ulong);
28
29impl Flags {
30 /// Use the interrupt line as already configured.
31 pub const TRIGGER_NONE: Flags = Flags::new(bindings::IRQF_TRIGGER_NONE);
32
33 /// The interrupt is triggered when the signal goes from low to high.
34 pub const TRIGGER_RISING: Flags = Flags::new(bindings::IRQF_TRIGGER_RISING);
35
36 /// The interrupt is triggered when the signal goes from high to low.
37 pub const TRIGGER_FALLING: Flags = Flags::new(bindings::IRQF_TRIGGER_FALLING);
38
39 /// The interrupt is triggered while the signal is held high.
40 pub const TRIGGER_HIGH: Flags = Flags::new(bindings::IRQF_TRIGGER_HIGH);
41
42 /// The interrupt is triggered while the signal is held low.
43 pub const TRIGGER_LOW: Flags = Flags::new(bindings::IRQF_TRIGGER_LOW);
44
45 /// Allow sharing the IRQ among several devices.
46 pub const SHARED: Flags = Flags::new(bindings::IRQF_SHARED);
47
48 /// Set by callers when they expect sharing mismatches to occur.
49 pub const PROBE_SHARED: Flags = Flags::new(bindings::IRQF_PROBE_SHARED);
50
51 /// Flag to mark this interrupt as timer interrupt.
52 pub const TIMER: Flags = Flags::new(bindings::IRQF_TIMER);
53
54 /// Interrupt is per CPU.
55 pub const PERCPU: Flags = Flags::new(bindings::IRQF_PERCPU);
56
57 /// Flag to exclude this interrupt from irq balancing.
58 pub const NOBALANCING: Flags = Flags::new(bindings::IRQF_NOBALANCING);
59
60 /// Interrupt is used for polling (only the interrupt that is registered
61 /// first in a shared interrupt is considered for performance reasons).
62 pub const IRQPOLL: Flags = Flags::new(bindings::IRQF_IRQPOLL);
63
64 /// Interrupt is not re-enabled after the hardirq handler finished. Used by
65 /// threaded interrupts which need to keep the irq line disabled until the
66 /// threaded handler has been run.
67 pub const ONESHOT: Flags = Flags::new(bindings::IRQF_ONESHOT);
68
69 /// Do not disable this IRQ during suspend. Does not guarantee that this
70 /// interrupt will wake the system from a suspended state.
71 pub const NO_SUSPEND: Flags = Flags::new(bindings::IRQF_NO_SUSPEND);
72
73 /// Force enable it on resume even if [`Flags::NO_SUSPEND`] is set.
74 pub const FORCE_RESUME: Flags = Flags::new(bindings::IRQF_FORCE_RESUME);
75
76 /// Interrupt cannot be threaded.
77 pub const NO_THREAD: Flags = Flags::new(bindings::IRQF_NO_THREAD);
78
79 /// Resume IRQ early during syscore instead of at device resume time.
80 pub const EARLY_RESUME: Flags = Flags::new(bindings::IRQF_EARLY_RESUME);
81
82 /// If the IRQ is shared with a [`Flags::NO_SUSPEND`] user, execute this
83 /// interrupt handler after suspending interrupts. For system wakeup devices
84 /// users need to implement wakeup detection in their interrupt handlers.
85 pub const COND_SUSPEND: Flags = Flags::new(bindings::IRQF_COND_SUSPEND);
86
87 /// Don't enable IRQ or NMI automatically when users request it. Users will
88 /// enable it explicitly by `enable_irq` or `enable_nmi` later.
89 pub const NO_AUTOEN: Flags = Flags::new(bindings::IRQF_NO_AUTOEN);
90
91 /// Exclude from runnaway detection for IPI and similar handlers, depends on
92 /// `PERCPU`.
93 pub const NO_DEBUG: Flags = Flags::new(bindings::IRQF_NO_DEBUG);
94
95 pub(crate) fn into_inner(self) -> c_ulong {
96 self.0
97 }
98
99 // Always inline to optimize out error path of `build_assert`.
100 #[inline(always)]
101 const fn new(value: u32) -> Self {
102 build_assert!(value as u64 <= c_ulong::MAX as u64);
103 Self(value as c_ulong)
104 }
105}
106
107impl core::ops::BitOr for Flags {
108 type Output = Self;
109 fn bitor(self, rhs: Self) -> Self::Output {
110 Self(self.0 | rhs.0)
111 }
112}
113
114impl core::ops::BitAnd for Flags {
115 type Output = Self;
116 fn bitand(self, rhs: Self) -> Self::Output {
117 Self(self.0 & rhs.0)
118 }
119}
120
121impl core::ops::Not for Flags {
122 type Output = Self;
123 fn not(self) -> Self::Output {
124 Self(!self.0)
125 }
126}