BF533_EZ-Kit_Lite API function

Hi,

I am now reading Button_LED_GPIO example code of BF533 EZ-Kit Lite. In main(), i a reading some functions as below:

ADI_GPIO_RESULT result = adi_gpio_Init(
(void*)gpioMemory,
GPIO_MEMORY_SIZE,
&gpioMaxCallbacks);

result = adi_gpio_EnableInterruptMask(
PUSH_BUTTON1_PORT,
PUSH_BUTTON1_PIN,
PUSH_BUTTON1_INT_CHNL,
true);
CheckResult(result);

// register gpio callback
result = adi_gpio_RegisterCallback(
PUSH_BUTTON1_PORT,
PUSH_BUTTON1_PIN,
gpioCallback,
(void*)0);

As my understanding, the functions: adi_gpio_Init(), EnableInterruptMask(), RegisterCallback() are the API function of BF533. I do not know my understanding is true or false ? Beside, i have search this functions, but i only found the definication of them. E.g: The definication of adi_gpio_Init() is as below:

ADI_GPIO_RESULT adi_gpio_SetDirection(
ADI_GPIO_PORT const ePort,
uint32_t const Pins,
ADI_GPIO_DIRECTION const eDirection
);

With this definication, i do now know about what is inside the function? How they work? Is there any document description detail about this functions ?