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 index(&self) -> usize29 fn index(&self) -> usize { 30 self.0.driver_data 31 } 32 } 33 34 impl DeviceId { 35 const ACPI_ID_LEN: usize = 16; 36 37 /// Create a new device id from an ACPI 'id' string. 38 #[inline(always)] new(id: &'static CStr) -> Self39 pub const fn new(id: &'static CStr) -> Self { 40 build_assert!( 41 id.len_with_nul() <= Self::ACPI_ID_LEN, 42 "ID exceeds 16 bytes" 43 ); 44 let src = id.as_bytes_with_nul(); 45 // Replace with `bindings::acpi_device_id::default()` once stabilized for `const`. 46 // SAFETY: FFI type is valid to be zero-initialized. 47 let mut acpi: bindings::acpi_device_id = unsafe { core::mem::zeroed() }; 48 let mut i = 0; 49 while i < src.len() { 50 acpi.id[i] = src[i]; 51 i += 1; 52 } 53 54 Self(acpi) 55 } 56 } 57 58 /// Create an ACPI `IdTable` with an "alias" for modpost. 59 #[macro_export] 60 macro_rules! acpi_device_table { 61 ($table_name:ident, $module_table_name:ident, $id_info_type: ty, $table_data: expr) => { 62 const $table_name: $crate::device_id::IdArray< 63 $crate::acpi::DeviceId, 64 $id_info_type, 65 { $table_data.len() }, 66 > = $crate::device_id::IdArray::new($table_data); 67 68 $crate::module_device_table!("acpi", $module_table_name, $table_name); 69 }; 70 } 71