Low Power Callbacks

Functions
bool	Cy_SysPm_RegisterCallback (cy_stc_syspm_callback_t *handler)
	Registers a new syspm callback. More...
bool	Cy_SysPm_UnregisterCallback (cy_stc_syspm_callback_t const *handler)
	This function unregisters a callback. More...
cy_en_syspm_status_t	Cy_SysPm_ExecuteCallback (cy_en_syspm_callback_type_t type, cy_en_syspm_callback_mode_t mode)
	The function executes all registered callbacks with provided type and mode. More...
cy_stc_syspm_callback_t *	Cy_SysPm_GetFailedCallback (cy_en_syspm_callback_type_t type)
	Reads the result of the callback execution after the power mode functions execution. More...

Detailed Description

Function Documentation

Cy_SysPm_RegisterCallback()

bool Cy_SysPm_RegisterCallback

(

cy_stc_syspm_callback_t *

handler

)

Registers a new syspm callback.

A callback is a function called after an event in the driver or middleware module has occurred. The handler callback API will be executed if the specific event occurs. See cy_stc_syspm_callback_t. User is responsible for defining a separate buffer for each of the power modes registered lists.

Note

The registered callbacks are executed in two orders, based on callback mode cy_en_syspm_callback_mode_t. For modes CY_SYSPM_CHECK_READY and CY_SYSPM_BEFORE_TRANSITION, the order as follows: the first registered callback will be always the first executed. And the last registered callback will be executed as the last callback. For modes CY_SYSPM_AFTER_TRANSITION and CY_SYSPM_CHECK_FAIL, the order is as follows: the first registered callback will be always the last executed. And the last registered callback will be executed as the first callback.

Parameters

handler

The address of the syspm callback structure. See cy_stc_syspm_callback_t.

Note

Do not modify the registered structure in run-time.

Returns

• True if a callback was registered.
• False if a callback was not registered or maximum callbacks were registered.

Warning

After being registered, the SysPm callback structures must be allocated during power mode transition.

Cy_SysPm_UnregisterCallback()

bool Cy_SysPm_UnregisterCallback

(

cy_stc_syspm_callback_t const *

handler

)

This function unregisters a callback.

The registered callback will be unregistered. Otherwise, false will be returned.

Parameters

handler

The item that should be unregistered. See cy_stc_syspm_callback_t.

Returns

• True if callback was unregistered.
• False if it was not unregistered or no callbacks are registered.

Cy_SysPm_ExecuteCallback()

cy_en_syspm_status_t Cy_SysPm_ExecuteCallback	(	cy_en_syspm_callback_type_t	type,
		cy_en_syspm_callback_mode_t	mode
	)

The function executes all registered callbacks with provided type and mode.

Note

The registered callbacks will be executed in order based on lastCallback value. There are two possible callback execution orders:

• From first registered to last registered. This order applies to callbacks with mode CY_SYSPM_CHECK_READY and ref\ CY_SYSPM_BEFORE_TRANSITION.
• Backward flow execution: from last executed callback to the first registered. Such order is relevant to callbacks with mode CY_SYSPM_AFTER_TRANSITION and CY_SYSPM_CHECK_FAIL. Note that, the last registered callback function is skipped with mode CY_SYSPM_CHECK_FAIL. This is because callback which returned CY_SYSPM_FAIL already know that it failed.

If no callbacks are registered, returns CY_SYSPM_SUCCESS.

Parameters

type	The callback type. See cy_en_syspm_callback_type_t.
mode	The callback mode. See cy_en_syspm_callback_mode_t.

Returns

• CY_SYSPM_SUCCESS if callback successfully completed or nor callbacks registered.
• CY_SYSPM_FAIL one of the executed callback(s) returned fail.

Cy_SysPm_GetFailedCallback()

cy_stc_syspm_callback_t* Cy_SysPm_GetFailedCallback

(

cy_en_syspm_callback_type_t

type

)

Reads the result of the callback execution after the power mode functions execution.

This function reads the value of the pointer that stores the result of callback execution. It takes power mode as the parameter and returns the address of the callback configuration structure in the case of failure or NULL in the case of success. This address of the failed callback allows finding the callback that blocks entering power mode.

Parameters

type	Power mode for which a callback execution result is required.

Returns

• The address of the callback configuration structure if the callback handler function failed.
• NULL if the callback skipped or executed successfully.