diff options
author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2025-09-29 10:10:05 +0200 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2025-09-29 10:10:05 +0200 |
commit | 17eb8812917b10ce4146b5595f91d8e45bfe68cc (patch) | |
tree | f905aa6c71212f4b460e23ceaec98346b999066a /rust/kernel/driver.rs | |
parent | 57610d69f909ea2ea072775c6ad64ba9fad590bb (diff) | |
parent | 23199d2aa6dcaf6dd2da772f93d2c94317d71459 (diff) |
Merge tag 'linux-cpupower-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux
Merge cpupower utility updates for 6.18-rc1 from Shuah Khan:
"Fixes incorrect return vale in cpupower_write_sysfs() error path
and passing incorrect size to cpuidle_state_write_file() while
writing status to disable file in cpuidle_state_disable()."
* tag 'linux-cpupower-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux: (1125 commits)
tools/cpupower: Fix incorrect size in cpuidle_state_disable()
tools/cpupower: fix error return value in cpupower_write_sysfs()
Linux 6.17-rc6
MAINTAINERS: Input: Drop melfas-mip4 section
USB: core: remove the move buf action
MAINTAINERS: Update the DMA Rust entry
erofs: fix long xattr name prefix placement
Revert "net: usb: asix: ax88772: drop phylink use in PM to avoid MDIO runtime PM wakeups"
hsr: hold rcu and dev lock for hsr_get_port_ndev
hsr: use hsr_for_each_port_rtnl in hsr_port_get_hsr
hsr: use rtnl lock when iterating over ports
wifi: nl80211: completely disable per-link stats for now
net: usb: asix: ax88772: drop phylink use in PM to avoid MDIO runtime PM wakeups
net: ethtool: fix wrong type used in struct kernel_ethtool_ts_info
selftests/bpf: Skip timer cases when bpf_timer is not supported
bpf: Reject bpf_timer for PREEMPT_RT
libceph: fix invalid accesses to ceph_connection_v1_info
PM: hibernate: Restrict GFP mask in hibernation_snapshot()
MAINTAINERS: add Phil as netfilter reviewer
netfilter: nf_tables: restart set lookup on base_seq change
...
Diffstat (limited to 'rust/kernel/driver.rs')
-rw-r--r-- | rust/kernel/driver.rs | 89 |
1 files changed, 87 insertions, 2 deletions
diff --git a/rust/kernel/driver.rs b/rust/kernel/driver.rs index a8f2675ba7a7..279e3af20682 100644 --- a/rust/kernel/driver.rs +++ b/rust/kernel/driver.rs @@ -2,8 +2,93 @@ //! Generic support for drivers of different buses (e.g., PCI, Platform, Amba, etc.). //! -//! Each bus / subsystem is expected to implement [`RegistrationOps`], which allows drivers to -//! register using the [`Registration`] class. +//! This documentation describes how to implement a bus specific driver API and how to align it with +//! the design of (bus specific) devices. +//! +//! Note: Readers are expected to know the content of the documentation of [`Device`] and +//! [`DeviceContext`]. +//! +//! # Driver Trait +//! +//! The main driver interface is defined by a bus specific driver trait. For instance: +//! +//! ```ignore +//! pub trait Driver: Send { +//! /// The type holding information about each device ID supported by the driver. +//! type IdInfo: 'static; +//! +//! /// The table of OF device ids supported by the driver. +//! const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = None; +//! +//! /// The table of ACPI device ids supported by the driver. +//! const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = None; +//! +//! /// Driver probe. +//! fn probe(dev: &Device<device::Core>, id_info: &Self::IdInfo) -> Result<Pin<KBox<Self>>>; +//! +//! /// Driver unbind (optional). +//! fn unbind(dev: &Device<device::Core>, this: Pin<&Self>) { +//! let _ = (dev, this); +//! } +//! } +//! ``` +//! +//! For specific examples see [`auxiliary::Driver`], [`pci::Driver`] and [`platform::Driver`]. +//! +//! The `probe()` callback should return a `Result<Pin<KBox<Self>>>`, i.e. the driver's private +//! data. The bus abstraction should store the pointer in the corresponding bus device. The generic +//! [`Device`] infrastructure provides common helpers for this purpose on its +//! [`Device<CoreInternal>`] implementation. +//! +//! All driver callbacks should provide a reference to the driver's private data. Once the driver +//! is unbound from the device, the bus abstraction should take back the ownership of the driver's +//! private data from the corresponding [`Device`] and [`drop`] it. +//! +//! All driver callbacks should provide a [`Device<Core>`] reference (see also [`device::Core`]). +//! +//! # Adapter +//! +//! The adapter implementation of a bus represents the abstraction layer between the C bus +//! callbacks and the Rust bus callbacks. It therefore has to be generic over an implementation of +//! the [driver trait](#driver-trait). +//! +//! ```ignore +//! pub struct Adapter<T: Driver>; +//! ``` +//! +//! There's a common [`Adapter`] trait that can be implemented to inherit common driver +//! infrastructure, such as finding the ID info from an [`of::IdTable`] or [`acpi::IdTable`]. +//! +//! # Driver Registration +//! +//! In order to register C driver types (such as `struct platform_driver`) the [adapter](#adapter) +//! should implement the [`RegistrationOps`] trait. +//! +//! This trait implementation can be used to create the actual registration with the common +//! [`Registration`] type. +//! +//! Typically, bus abstractions want to provide a bus specific `module_bus_driver!` macro, which +//! creates a kernel module with exactly one [`Registration`] for the bus specific adapter. +//! +//! The generic driver infrastructure provides a helper for this with the [`module_driver`] macro. +//! +//! # Device IDs +//! +//! Besides the common device ID types, such as [`of::DeviceId`] and [`acpi::DeviceId`], most buses +//! may need to implement their own device ID types. +//! +//! For this purpose the generic infrastructure in [`device_id`] should be used. +//! +//! [`auxiliary::Driver`]: kernel::auxiliary::Driver +//! [`Core`]: device::Core +//! [`Device`]: device::Device +//! [`Device<Core>`]: device::Device<device::Core> +//! [`Device<CoreInternal>`]: device::Device<device::CoreInternal> +//! [`DeviceContext`]: device::DeviceContext +//! [`device_id`]: kernel::device_id +//! [`module_driver`]: kernel::module_driver +//! [`pci::Driver`]: kernel::pci::Driver +//! [`platform::Driver`]: kernel::platform::Driver use crate::error::{Error, Result}; use crate::{acpi, device, of, str::CStr, try_pin_init, types::Opaque, ThisModule}; |