1 // SPDX-License-Identifier: GPL-2.0 2 3 //! Advanced Configuration and Power Interface abstractions. 4 5 use crate::{ 6 bindings, 7 device_id::{RawDeviceId, RawDeviceIdIndex}, 8 prelude::*, 9 }; 10 11 /// IdTable type for ACPI drivers. 12 pub type IdTable<T> = &'static dyn kernel::device_id::IdTable<DeviceId, T>; 13 14 /// An ACPI device id. 15 #[repr(transparent)] 16 #[derive(Clone, Copy)] 17 pub 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`. 21 unsafe 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. 26 unsafe impl RawDeviceIdIndex for DeviceId { 27 const DRIVER_DATA_OFFSET: usize = core::mem::offset_of!(bindings::acpi_device_id, driver_data); 28 } 29 30 impl 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] 51 macro_rules! acpi_device_table { 52 ($($tt:tt)*) => { 53 $crate::module_device_table!("acpi", $crate::acpi::DeviceId, $($tt)*); 54 }; 55 } 56