projects/linux·blob master · refs

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1// SPDX-License-Identifier: GPL-2.0
2
3//! Advanced Configuration and Power Interface abstractions.
4
5use crate::{
6 bindings,
7 device_id::{RawDeviceId, RawDeviceIdIndex},
8 prelude::*,
9};
10
11/// IdTable type for ACPI drivers.
12pub type IdTable<T> = &'static dyn kernel::device_id::IdTable<DeviceId, T>;
13
14/// An ACPI device id.
15#[repr(transparent)]
16#[derive(Clone, Copy)]
17pub struct DeviceId(bindings::acpi_device_id);
18
19// SAFETY: `DeviceId` is a `#[repr(transparent)]` wrapper of `acpi_device_id` and does not add
20// additional invariants, so it's safe to transmute to `RawType`.
21unsafe impl RawDeviceId for DeviceId {
22 type RawType = bindings::acpi_device_id;
23}
24
25// SAFETY: `DRIVER_DATA_OFFSET` is the offset to the `driver_data` field.
26unsafe impl RawDeviceIdIndex for DeviceId {
27 const DRIVER_DATA_OFFSET: usize = core::mem::offset_of!(bindings::acpi_device_id, driver_data);
28}
29
30impl DeviceId {
31 const ACPI_ID_LEN: usize = 16;
32
33 /// Create a new device id from an ACPI 'id' string.
34 #[inline(always)]
35 pub const fn new(id: &'static CStr) -> Self {
36 let src = id.to_bytes_with_nul();
37 build_assert!(src.len() <= Self::ACPI_ID_LEN, "ID exceeds 16 bytes");
38 let mut acpi: bindings::acpi_device_id = pin_init::zeroed();
39 let mut i = 0;
40 while i < src.len() {
41 acpi.id[i] = src[i];
42 i += 1;
43 }
44
45 Self(acpi)
46 }
47}
48
49/// Create an ACPI `IdTable` with an "alias" for modpost.
50#[macro_export]
51macro_rules! acpi_device_table {
52 ($($tt:tt)*) => {
53 $crate::module_device_table!("acpi", $crate::acpi::DeviceId, $($tt)*);
54 };
55}