Struct Registration

pub struct Registration<T: Driver>(/* private fields */);

CPU frequency driver Registration.

Examples

The following example demonstrates how to register a cpufreq driver.

use kernel::{
    cpu, cpufreq,
    c_str,
    device::{Bound, Device},
    macros::vtable,
    sync::Arc,
};
struct FooDevice;

#[derive(Default)]
struct FooDriver;

#[vtable]
impl cpufreq::Driver for FooDriver {
    const NAME: &'static CStr = c_str!("cpufreq-foo");
    const FLAGS: u16 = cpufreq::flags::NEED_INITIAL_FREQ_CHECK | cpufreq::flags::IS_COOLING_DEV;
    const BOOST_ENABLED: bool = true;

    type PData = Arc<FooDevice>;

    fn init(policy: &mut cpufreq::Policy) -> Result<Self::PData> {
        // Initialize here
        Ok(Arc::new(FooDevice, GFP_KERNEL)?)
    }

    fn exit(_policy: &mut cpufreq::Policy, _data: Option<Self::PData>) -> Result<()> {
        Ok(())
    }

    fn suspend(policy: &mut cpufreq::Policy) -> Result<()> {
        policy.generic_suspend()
    }

    fn verify(data: &mut cpufreq::PolicyData) -> Result<()> {
        data.generic_verify()
    }

    fn target_index(policy: &mut cpufreq::Policy, index: cpufreq::TableIndex) -> Result<()> {
        // Update CPU frequency
        Ok(())
    }

    fn get(policy: &mut cpufreq::Policy) -> Result<u32> {
        policy.generic_get()
    }
}

fn foo_probe(dev: &Device<Bound>) {
    cpufreq::Registration::<FooDriver>::new_foreign_owned(dev).unwrap();
}

Implementations

impl<T: Driver> Registration<T>

pub fn new() -> Result<Self>

Registers a CPU frequency driver with the cpufreq core.

pub fn new_foreign_owned(dev: &Device<Bound>) -> Result<()>

Same as Registration::new, but does not return a Registration instance.

Instead the Registration is owned by Devres and will be revoked / dropped, once the device is detached.

Trait Implementations

impl<T: Driver> Drop for Registration<T>

fn drop(&mut self)

Unregisters with the cpufreq core.

impl<T: Driver> Send for Registration<T>

SAFETY: Registration with and unregistration from the cpufreq subsystem can happen from any thread.

impl<T: Driver> Sync for Registration<T>

SAFETY: Registration doesn’t offer any methods or access to fields when shared between threads or CPUs, so it is safe to share it.