Clock Control

Overview

The clock control API provides access to clocks in the system, including the ability to turn them on and off.

Configuration Options

Related configuration options:

API Reference

group clock_control_interface

Clock Control Interface.

Defines

CLOCK_CONTROL_SUBSYS_ALL

Typedefs

typedef void *clock_control_subsys_t

clock_control_subsys_t is a type to identify a clock controller sub-system. Such data pointed is opaque and relevant only to the clock controller driver instance being used.

typedef void (*clock_control_cb_t)(const struct device *dev, clock_control_subsys_t subsys, void *user_data)

Callback called on clock started.

Parameters

  • dev: Device structure whose driver controls the clock.

  • subsys: Opaque data representing the clock.

  • user_data: User data.

typedef int (*clock_control)(const struct device *dev, clock_control_subsys_t sys)
typedef int (*clock_control_get)(const struct device *dev, clock_control_subsys_t sys, uint32_t *rate)
typedef int (*clock_control_async_on_fn)(const struct device *dev, clock_control_subsys_t sys, clock_control_cb_t cb, void *user_data)
typedef enum clock_control_status (*clock_control_get_status_fn)(const struct device *dev, clock_control_subsys_t sys)

Enums

enum clock_control_status

Current clock status.

Values:

enumerator CLOCK_CONTROL_STATUS_STARTING
enumerator CLOCK_CONTROL_STATUS_OFF
enumerator CLOCK_CONTROL_STATUS_ON
enumerator CLOCK_CONTROL_STATUS_UNKNOWN

Functions

int clock_control_on(const struct device *dev, clock_control_subsys_t sys)

Enable a clock controlled by the device.

On success, the clock is enabled and ready when this function returns. This function may sleep, and thus can only be called from thread context.

Use clock_control_async_on() for non-blocking operation.

Return

0 on success, negative errno on failure.

Parameters

  • dev: Device structure whose driver controls the clock.

  • sys: Opaque data representing the clock.

int clock_control_off(const struct device *dev, clock_control_subsys_t sys)

Disable a clock controlled by the device.

This function is non-blocking and can be called from any context. On success, the clock is disabled when this function returns.

Return

0 on success, negative errno on failure.

Parameters

  • dev: Device structure whose driver controls the clock

  • sys: Opaque data representing the clock

int clock_control_async_on(const struct device *dev, clock_control_subsys_t sys, clock_control_cb_t cb, void *user_data)

Request clock to start with notification when clock has been started.

Function is non-blocking and can be called from any context. User callback is called when clock is started.

Parameters

  • dev: Device.

  • sys: A pointer to an opaque data representing the sub-system.

  • cb: Callback.

  • user_data: User context passed to the callback.

Return Value

  • 0: if start is successfully initiated.

  • -EALREADY: if clock was already started and is starting or running.

  • -ENOTSUP: if not supported.

  • other: negative errno on vendor specific error.

enum clock_control_status clock_control_get_status(const struct device *dev, clock_control_subsys_t sys)

Get clock status.

Return

Status.

Parameters

  • dev: Device.

  • sys: A pointer to an opaque data representing the sub-system.

int clock_control_get_rate(const struct device *dev, clock_control_subsys_t sys, uint32_t *rate)

Obtain the clock rate of given sub-system.

Parameters

  • dev: Pointer to the device structure for the clock controller driver instance

  • sys: A pointer to an opaque data representing the sub-system

  • [out] rate: Subsystem clock rate

struct clock_control_driver_api
#include <clock_control.h>