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