Struct Policy

pub struct Policy(/* private fields */);

CPU frequency policy.

Rust abstraction for the C struct cpufreq_policy.

Invariants

A Policy instance always corresponds to a valid C struct cpufreq_policy.

The callers must ensure that the struct cpufreq_policy is valid for access and remains valid for the lifetime of the returned reference.

Examples

The following example demonstrates how to create a CPU frequency table.

use kernel::cpufreq::{ETERNAL_LATENCY_NS, Policy};

fn update_policy(policy: &mut Policy) {
    policy
        .set_dvfs_possible_from_any_cpu(true)
        .set_fast_switch_possible(true)
        .set_transition_latency_ns(ETERNAL_LATENCY_NS);

    pr_info!("The policy details are: {:?}\n", (policy.cpu(), policy.cur()));
}

Implementations

impl Policy

pub unsafe fn from_raw<'a>(ptr: *const cpufreq_policy) -> &'a Self

Creates a reference to an existing struct cpufreq_policy pointer.

Safety

The caller must ensure that ptr is valid for reading and remains valid for the lifetime of the returned reference.

pub unsafe fn from_raw_mut<'a>(ptr: *mut cpufreq_policy) -> &'a mut Self

Creates a mutable reference to an existing struct cpufreq_policy pointer.

Safety

The caller must ensure that ptr is valid for writing and remains valid for the lifetime of the returned reference.

pub fn cpu(&self) -> CpuId

Returns the primary CPU for the Policy.

pub fn min(&self) -> Hertz

Returns the minimum frequency for the Policy.

pub fn set_min(&mut self, min: Hertz) -> &mut Self

Set the minimum frequency for the Policy.

pub fn max(&self) -> Hertz

Returns the maximum frequency for the Policy.

pub fn set_max(&mut self, max: Hertz) -> &mut Self

Set the maximum frequency for the Policy.

pub fn cur(&self) -> Hertz

Returns the current frequency for the Policy.

pub fn suspend_freq(&self) -> Hertz

Returns the suspend frequency for the Policy.

pub fn set_suspend_freq(&mut self, freq: Hertz) -> &mut Self

Sets the suspend frequency for the Policy.

pub fn generic_suspend(&mut self) -> Result

Provides a wrapper to the generic suspend routine.

pub fn generic_get(&self) -> Result<u32>

Provides a wrapper to the generic get routine.

pub fn register_em_opp(&mut self)

Provides a wrapper to the register with energy model using the OPP core.

pub fn cpus(&mut self) -> &mut Cpumask

Gets cpumask::Cpumask for a cpufreq Policy.

pub unsafe fn set_clk( &mut self, dev: &Device, name: Option<&CStr>, ) -> Result<Clk>

Sets clock for the Policy.

Safety

The caller must guarantee that the returned Clk is not dropped while it is getting used by the C code.

pub fn set_dvfs_possible_from_any_cpu(&mut self, val: bool) -> &mut Self

Allows / disallows frequency switching code to run on any CPU.

pub fn fast_switch_possible(&self) -> bool

Returns if fast switching of frequencies is possible or not.

pub fn set_fast_switch_possible(&mut self, val: bool) -> &mut Self

Enables / disables fast frequency switching.

pub fn set_transition_latency_ns(&mut self, latency_ns: u32) -> &mut Self

Sets transition latency (in nanoseconds) for the Policy.

pub fn set_cpuinfo_min_freq(&mut self, min_freq: Hertz) -> &mut Self

Sets cpuinfo min_freq.

pub fn set_cpuinfo_max_freq(&mut self, max_freq: Hertz) -> &mut Self

Sets cpuinfo max_freq.

pub fn set_transition_delay_us(&mut self, transition_delay_us: u32) -> &mut Self

Set transition_delay_us, i.e. the minimum time between successive frequency change requests.

pub fn freq_table(&self) -> Result<&Table>

Returns reference to the CPU frequency Table for the Policy.

pub unsafe fn set_freq_table(&mut self, table: &Table) -> &mut Self

Sets the CPU frequency Table for the Policy.

Safety

The caller must guarantee that the Table is not dropped while it is getting used by the C code.

pub fn data<T: ForeignOwnable>(&mut self) -> Option<T::Borrowed<'_>>

Returns the Policy’s private data.