GPIO Interface

Driver API for GPIO Interface (Driver_GPIO.h) More...

Content
	GPIO Status Error Codes
	Negative values indicate errors (GPIO has specific codes in addition to common Status Error Codes).
	GPIO Events
	The GPIO driver generates call back events that are notified via the function ARM_GPIO_SignalEvent.

Data Structures
struct	ARM_DRIVER_GPIO
	Access structure of the GPIO Driver. More...

Typedefs
typedef void(*	ARM_GPIO_SignalEvent_t) (ARM_GPIO_Pin_t pin, uint32_t event)

Enumerations
enum	ARM_GPIO_DIRECTION {   ARM_GPIO_INPUT ,   ARM_GPIO_OUTPUT }
	GPIO Direction. More...
enum	ARM_GPIO_OUTPUT_MODE {   ARM_GPIO_PUSH_PULL ,   ARM_GPIO_OPEN_DRAIN }
	GPIO Output Mode. More...
enum	ARM_GPIO_PULL_RESISTOR {   ARM_GPIO_PULL_NONE ,   ARM_GPIO_PULL_UP ,   ARM_GPIO_PULL_DOWN }
	GPIO Pull Resistor. More...
enum	ARM_GPIO_EVENT_TRIGGER {   ARM_GPIO_TRIGGER_NONE ,   ARM_GPIO_TRIGGER_RISING_EDGE ,   ARM_GPIO_TRIGGER_FALLING_EDGE ,   ARM_GPIO_TRIGGER_EITHER_EDGE }
	GPIO Event Trigger. More...

Functions
int32_t	ARM_GPIO_Setup (ARM_GPIO_Pin_t pin, ARM_GPIO_SignalEvent_t cb_event)
	Setup GPIO Interface.
int32_t	ARM_GPIO_SetDirection (ARM_GPIO_Pin_t pin, ARM_GPIO_DIRECTION direction)
	Set GPIO Direction.
int32_t	ARM_GPIO_SetOutputMode (ARM_GPIO_Pin_t pin, ARM_GPIO_OUTPUT_MODE mode)
	Set GPIO Output Mode.
int32_t	ARM_GPIO_SetPullResistor (ARM_GPIO_Pin_t pin, ARM_GPIO_PULL_RESISTOR resistor)
	Set GPIO Pull Resistor.
int32_t	ARM_GPIO_SetEventTrigger (ARM_GPIO_Pin_t pin, ARM_GPIO_EVENT_TRIGGER trigger)
	Set GPIO Event Trigger.
void	ARM_GPIO_SetOutput (ARM_GPIO_Pin_t pin, uint32_t val)
	Set GPIO Output Level.
uint32_t	ARM_GPIO_GetInput (ARM_GPIO_Pin_t pin)
	Get GPIO Input Level.
void	ARM_GPIO_SignalEvent (ARM_GPIO_Pin_t pin, uint32_t event)
	Signal GPIO Events.

Description

Driver API for GPIO Interface (Driver_GPIO.h)

The General-purpose Input/Output Interface (GPIO) features Input/Output operations on pin level (does not support simultaneous operations on multiple pins belonging to the same port).

Features:

• basic pin configuration (direction, output mode, pull-resistor, event trigger) excluding advanced settings (drive strength or speed, input filter, ...),
• events on edge detection,
• setting outputs,
• reading inputs.

Each function operates on a pin level and uses a pin identification as the first parameter. Pin identification is a virtual number which is mapped to an actual pin.

GPIO API

The following header files define the Application Programming Interface (API) for the GPIO interface:

• Driver_GPIO.h : Driver API for GPIO Interface

The driver implementation is a typical part of the Device Family Pack (DFP) that supports the peripherals of the microcontroller family.

Driver Functions

The driver functions are published in the access struct as explained in Common Driver Functions

• ARM_DRIVER_GPIO : access struct for GPIO driver functions

Example Code

The following example code shows the usage of the GPIO interface.

#include "Driver_GPIO.h"
 
/* GPIO driver instance */
extern ARM_DRIVER_GPIO             Driver_GPIO0;
static ARM_DRIVER_GPIO *GPIOdrv = &Driver_GPIO0;
 
/* Pin mapping */
#define GPIO_PIN0       0U
#define GPIO_PIN1       1U
#define GPIO_PIN2       2U
#define GPIO_PIN3       3U
 
/* GPIO Signal Event callback */
static void GPIO_SignalEvent (ARM_GPIO_Pin_t pin, uint32_t event) {
 
  switch (pin) {
    case GPIO_PIN1:
      /* Events on pin GPIO_PIN1 */
      if (event & ARM_GPIO_EVENT_RISING_EDGE) {
        /* Rising-edge detected */
      }
      if (event & ARM_GPIO_EVENT_FALLING_EDGE) {
        /* Falling-edge detected */
      }
      break;
  }
}
 
/* Get GPIO Input 0 */
uint32_t GPIO_GetInput0 (void) {
  return (GPIOdrv->GetInput(GPIO_PIN0));
}
 
/* Get GPIO Input 1 */
uint32_t GPIO_GetInput1 (void) {
  return (GPIOdrv->GetInput(GPIO_PIN1));
}
 
/* Set GPIO Output Pin 2 */
void GPIO_SetOutput2 (uint32_t val) {
  GPIOdrv->SetOutput(GPIO_PIN2, val);
}
 
/* Set GPIO Output Pin 3 */
void GPIO_SetOutput3 (uint32_t val) {
  GPIOdrv->SetOutput(GPIO_PIN3, val);
}
 
/* Setup GPIO pins */
void GPIO_Setup (void) {
 
  /* Pin GPIO_PIN0: Input */
  GPIOdrv->Setup          (GPIO_PIN0, NULL);
  GPIOdrv->SetDirection   (GPIO_PIN0, ARM_GPIO_INPUT);
 
  /* Pin GPIO_PIN1: Input with trigger on rising and falling edge */
  GPIOdrv->Setup          (GPIO_PIN1, GPIO_SignalEvent);
  GPIOdrv->SetDirection   (GPIO_PIN1, ARM_GPIO_INPUT);
  GPIOdrv->SetEventTrigger(GPIO_PIN1, ARM_GPIO_TRIGGER_EITHER_EDGE);
 
  /* Pin GPIO_PIN2: Output push-pull (initial level 0) */
  GPIOdrv->Setup          (GPIO_PIN2, NULL);
  GPIOdrv->SetOutput      (GPIO_PIN2, 0U);
  GPIOdrv->SetDirection   (GPIO_PIN2, ARM_GPIO_OUTPUT);
 
  /* Pin GPIO_PIN3: Output open-drain with pull-up resistor (initial level 1) */
  GPIOdrv->Setup          (GPIO_PIN3, NULL);
  GPIOdrv->SetPullResistor(GPIO_PIN3, ARM_GPIO_PULL_UP);
  GPIOdrv->SetOutputMode  (GPIO_PIN3, ARM_GPIO_OPEN_DRAIN);
  GPIOdrv->SetOutput      (GPIO_PIN3, 1U);
  GPIOdrv->SetDirection   (GPIO_PIN3, ARM_GPIO_OUTPUT);
}

---

Data Structure Documentation

ARM_DRIVER_GPIO

struct ARM_DRIVER_GPIO

Access structure of the GPIO Driver.

The functions of the GPIO driver are accessed by function pointers exposed by this structure. Refer to Common Driver Functions for overview information.

Each instance of a GPIO interface provides such an access structure. The instance is identified by a postfix number in the symbol name of the access structure, for example:

• Driver_GPIO0 is the name of the access struct of the first instance (no. 0).
• Driver_GPIO1 is the name of the access struct of the second instance (no. 1).

A middleware configuration setting allows connecting the middleware to a specific driver instance Driver_GPIOn. The default is 0, which connects a middleware to the first instance of a driver.

Data Fields
int32_t(*	Setup )(ARM_GPIO_Pin_t pin, ARM_GPIO_SignalEvent_t cb_event)
	Pointer to ARM_GPIO_Setup : Setup GPIO Interface.
int32_t(*	SetDirection )(ARM_GPIO_Pin_t pin, ARM_GPIO_DIRECTION direction)
	Pointer to ARM_GPIO_SetDirection : Set GPIO Direction.
int32_t(*	SetOutputMode )(ARM_GPIO_Pin_t pin, ARM_GPIO_OUTPUT_MODE mode)
	Pointer to ARM_GPIO_SetOutputMode : Set GPIO Output Mode.
int32_t(*	SetPullResistor )(ARM_GPIO_Pin_t pin, ARM_GPIO_PULL_RESISTOR resistor)
	Pointer to ARM_GPIO_SetPullResistor : Set GPIO Pull Resistor.
int32_t(*	SetEventTrigger )(ARM_GPIO_Pin_t pin, ARM_GPIO_EVENT_TRIGGER trigger)
	Pointer to ARM_GPIO_SetEventTrigger : Set GPIO Event Trigger.
void(*	SetOutput )(ARM_GPIO_Pin_t pin, uint32_t val)
	Pointer to ARM_GPIO_SetOutput : Set GPIO Output Level.
uint32_t(*	GetInput )(ARM_GPIO_Pin_t pin)
	Pointer to ARM_GPIO_GetInput : Get GPIO Input Level.

Field Documentation

Setup

int32_t(* Setup) (ARM_GPIO_Pin_t pin, ARM_GPIO_SignalEvent_t cb_event)

Pointer to ARM_GPIO_Setup : Setup GPIO Interface.

SetDirection

int32_t(* SetDirection) (ARM_GPIO_Pin_t pin, ARM_GPIO_DIRECTION direction)

Pointer to ARM_GPIO_SetDirection : Set GPIO Direction.

SetOutputMode

int32_t(* SetOutputMode) (ARM_GPIO_Pin_t pin, ARM_GPIO_OUTPUT_MODE mode)

Pointer to ARM_GPIO_SetOutputMode : Set GPIO Output Mode.

SetPullResistor

int32_t(* SetPullResistor) (ARM_GPIO_Pin_t pin, ARM_GPIO_PULL_RESISTOR resistor)

Pointer to ARM_GPIO_SetPullResistor : Set GPIO Pull Resistor.

SetEventTrigger

int32_t(* SetEventTrigger) (ARM_GPIO_Pin_t pin, ARM_GPIO_EVENT_TRIGGER trigger)

Pointer to ARM_GPIO_SetEventTrigger : Set GPIO Event Trigger.

SetOutput

void(* SetOutput) (ARM_GPIO_Pin_t pin, uint32_t val)

Pointer to ARM_GPIO_SetOutput : Set GPIO Output Level.

GetInput

uint32_t(* GetInput) (ARM_GPIO_Pin_t pin)

Pointer to ARM_GPIO_GetInput : Get GPIO Input Level.

Typedef Documentation

ARM_GPIO_SignalEvent_t

ARM_GPIO_SignalEvent_t

Provides the typedef for the callback function ARM_GPIO_SignalEvent.

Parameter for:

• ARM_GPIO_Setup

Enumeration Type Documentation

ARM_GPIO_DIRECTION

enum ARM_GPIO_DIRECTION

GPIO Direction.

Specifies values for setting the direction.

Parameter for:

• ARM_GPIO_SetDirection

Enumerator
ARM_GPIO_INPUT	Input (default)
ARM_GPIO_OUTPUT	Output.

ARM_GPIO_OUTPUT_MODE

enum ARM_GPIO_OUTPUT_MODE

GPIO Output Mode.

Specifies values for setting the output mode.

Parameter for:

• ARM_GPIO_SetOutputMode

Enumerator
ARM_GPIO_PUSH_PULL	Push-pull (default)
ARM_GPIO_OPEN_DRAIN	Open-drain.

ARM_GPIO_PULL_RESISTOR

enum ARM_GPIO_PULL_RESISTOR

GPIO Pull Resistor.

Specifies values for setting the pull resistor.

Parameter for:

• ARM_GPIO_SetPullResistor

Enumerator
ARM_GPIO_PULL_NONE	None (default)
ARM_GPIO_PULL_UP	Pull-up.
ARM_GPIO_PULL_DOWN	Pull-down.

ARM_GPIO_EVENT_TRIGGER

enum ARM_GPIO_EVENT_TRIGGER

GPIO Event Trigger.

Specifies values for setting the event trigger.

Parameter for:

• ARM_GPIO_SetEventTrigger

Enumerator
ARM_GPIO_TRIGGER_NONE	None (default)
ARM_GPIO_TRIGGER_RISING_EDGE	Rising-edge.
ARM_GPIO_TRIGGER_FALLING_EDGE	Falling-edge.
ARM_GPIO_TRIGGER_EITHER_EDGE	Either edge (rising and falling)

Function Documentation

ARM_GPIO_Setup()

int32_t ARM_GPIO_Setup	(	ARM_GPIO_Pin_t	pin,
		ARM_GPIO_SignalEvent_t	cb_event
	)

Setup GPIO Interface.

Parameters

[in]	pin	GPIO Pin
[in]	cb_event	Pointer to ARM_GPIO_SignalEvent

Returns

Status Error Codes

The function ARM_GPIO_Setup sets-up the specified pin as GPIO with default configuration. Pin is configured as input without pull-resistor and without event trigger.

The parameter cb_event specifies a pointer to the ARM_GPIO_SignalEvent callback function to register. Use a NULL pointer when no callback events are required or to deregister a callback function.

ARM_GPIO_SetDirection()

int32_t ARM_GPIO_SetDirection	(	ARM_GPIO_Pin_t	pin,
		ARM_GPIO_DIRECTION	direction
	)

Set GPIO Direction.

Parameters

[in]	pin	GPIO Pin
[in]	direction	ARM_GPIO_DIRECTION

Returns

Status Error Codes

The function ARM_GPIO_SetDirection configures the direction of the specified pin.

Direction is specified with parameter direction:

• ARM_GPIO_INPUT : Input (default),
• ARM_GPIO_OUTPUT : Output.

ARM_GPIO_SetOutputMode()

int32_t ARM_GPIO_SetOutputMode	(	ARM_GPIO_Pin_t	pin,
		ARM_GPIO_OUTPUT_MODE	mode
	)

Set GPIO Output Mode.

Parameters

[in]	pin	GPIO Pin
[in]	mode	ARM_GPIO_OUTPUT_MODE

Returns

Status Error Codes

The function ARM_GPIO_SetOutputMode configures the output mode of the specified pin.

Output mode is specified with parameter mode:

• ARM_GPIO_PUSH_PULL : Push-pull (default),
• ARM_GPIO_OPEN_DRAIN : Open-drain.

Note

Output mode is relevant only when the pin is configured as output.

ARM_GPIO_SetPullResistor()

int32_t ARM_GPIO_SetPullResistor	(	ARM_GPIO_Pin_t	pin,
		ARM_GPIO_PULL_RESISTOR	resistor
	)

Set GPIO Pull Resistor.

Parameters

[in]	pin	GPIO Pin
[in]	resistor	ARM_GPIO_PULL_RESISTOR

Returns

Status Error Codes

The function ARM_GPIO_SetPullResistor configures the pull resistor of the specified pin.

Pull resistor is specified with parameter resistor:

• ARM_GPIO_PULL_NONE : None (default),
• ARM_GPIO_PULL_UP : Pull-up,
• ARM_GPIO_PULL_DOWN : Pull-down.

Note

Pull resistor applies to the pin regardless of pin direction.

ARM_GPIO_SetEventTrigger()

int32_t ARM_GPIO_SetEventTrigger	(	ARM_GPIO_Pin_t	pin,
		ARM_GPIO_EVENT_TRIGGER	trigger
	)

Set GPIO Event Trigger.

Parameters

[in]	pin	GPIO Pin
[in]	trigger	ARM_GPIO_EVENT_TRIGGER

Returns

Status Error Codes

The function ARM_GPIO_SetEventTrigger configures the event trigger of the specified pin.

Event trigger is specified with parameter trigger:

• ARM_GPIO_TRIGGER_NONE : None (default),
• ARM_GPIO_TRIGGER_RISING_EDGE : Rising-edge,
• ARM_GPIO_TRIGGER_FALLING_EDGE : Falling-edge,
• ARM_GPIO_TRIGGER_EITHER_EDGE : Either edge (rising and falling).

Note

To disable event trigger use trigger parameter ARM_GPIO_TRIGGER_NONE.

ARM_GPIO_SetOutput()

void ARM_GPIO_SetOutput	(	ARM_GPIO_Pin_t	pin,
		uint32_t	val
	)

Set GPIO Output Level.

Parameters

[in]	pin	GPIO Pin
[in]	val	GPIO Pin Level (0 or 1)

The function ARM_GPIO_SetOutput sets the level of the specified pin defined as output to the value specified by val.

Note

When a pin is configured as input, the level is latched and will be driven once the pin is configured as output.

ARM_GPIO_GetInput()

uint32_t ARM_GPIO_GetInput

(

ARM_GPIO_Pin_t

pin

)

Get GPIO Input Level.

Parameters

[in]

pin

GPIO Pin

Returns

GPIO Pin Level (0 or 1)

The function ARM_GPIO_GetInput reads the level of the specified pin.

ARM_GPIO_SignalEvent()

void ARM_GPIO_SignalEvent	(	ARM_GPIO_Pin_t	pin,
		uint32_t	event
	)

Signal GPIO Events.

Parameters

[in]	pin	GPIO Pin on which event occurred
[in]	event	GPIO Events notification mask

The function ARM_GPIO_SignalEvent is a callback functions registered by the function ARM_GPIO_Setup. It is called by the GPIO driver to notify the application about GPIO Events occurred during operation.

The parameter pin indicates on which pin the event occurred and parameter event indicates one or more events that occurred.

The following events can be generated:

Parameter event	Bit	Description
ARM_GPIO_EVENT_RISING_EDGE	0	Occurs when rising-edge is detected on the indicated pin.
ARM_GPIO_EVENT_FALLING_EDGE	1	Occurs when falling-edge is detected on the indicated pin.
ARM_GPIO_EVENT_EITHER_EDGE	2	Occurs when either edge is detected on the indicated pin when trigger is configured as ARM_GPIO_TRIGGER_EITHER_EDGE and hardware is not able to distinguish between rising and falling edge.