gpio.md

# GPIO
## **Overview**
Provides standard general-purpose input/output \(GPIO\) interfaces for driver development.
You can use this module to perform operations on a GPIO pin, including setting the input/output direction, reading/writing the level value, and setting the interrupt service routine \(ISR\) function.
**Since:**
1.0
## **Summary**
## Files

File Name	Description
gpio_if.h	Declares the standard GPIO interface functions.

## Typedefs

Typedef Name	Description
GpioIrqFunc) (uint16_t gpio, void *data)	typedef int32_t(* Defines the function type of a GPIO interrupt service routine (ISR).

## Enumerations

Enumeration Name	Description
GpioValue { GPIO_VAL_LOW = 0, GPIO_VAL_HIGH = 1, GPIO_VAL_ERR }	Enumerates GPIO level values.
GpioDirType { GPIO_DIR_IN = 0, GPIO_DIR_OUT = 1, GPIO_DIR_ERR }	Enumerates GPIO directions.

## Functions

Function Name	Description
GpioRead (uint16_t gpio, uint16_t *val)	int32_t Reads the level value of a GPIO pin.
GpioWrite (uint16_t gpio, uint16_t val)	int32_t Writes the level value for a GPIO pin.
GpioSetDir (uint16_t gpio, uint16_t dir)	int32_t Sets the input/output direction for a GPIO pin.
GpioGetDir (uint16_t gpio, uint16_t *dir)	int32_t Obtains the input/output direction of a GPIO pin.
GpioSetIrq (uint16_t gpio, uint16_t mode, GpioIrqFunc func, void *arg)	int32_t Sets the ISR function for a GPIO pin.
GpioUnSetIrq (uint16_t gpio)	int32_t Cancels the setting of the ISR function for a GPIO pin.
GpioEnableIrq (uint16_t gpio)	int32_t Enables a GPIO pin interrupt.
GpioDisableIrq (uint16_t gpio)	int32_t Disables a GPIO pin interrupt.

## **Details**
## **Typedef Documentation**
## GpioIrqFunc
```
typedef int32_t(* GpioIrqFunc) (uint16_t gpio, void *data)
```
**Description:**
Defines the function type of a GPIO interrupt service routine \(ISR\).
This function is used when you call [GpioSetIrq](gpio.md#ga6ea5d16b8d73cb74e36d367f05cb7f6e) to register the ISR for a GPIO pin.
**Parameters:**

Name	Description
gpio	Indicates the GPIO number of the ISR.
data	Indicates the pointer to the private data passed to this ISR (The data is specified when the ISR is registered).

**Returns:**
Returns **0** if the ISR function type is successfully defined; returns a negative value otherwise.
**See also:**
[GpioSetIrq](gpio.md#ga6ea5d16b8d73cb74e36d367f05cb7f6e)
## **Enumeration Type Documentation**
## GpioDirType
```
enum [GpioDirType](gpio.md#ga71f27d3ba7ca04d9448199fca38ae19d)
```
**Description:**
Enumerates GPIO directions.

Enumerator	Description
GPIO_DIR_IN	Input direction
GPIO_DIR_OUT	Output direction
GPIO_DIR_ERR	Invalid direction

## GpioValue
```
enum [GpioValue](gpio.md#ga6a25a3efddf2301c7b01a7f0af44fb11)
```
**Description:**
Enumerates GPIO level values.

Enumerator	Description
GPIO_VAL_LOW	Low GPIO level
GPIO_VAL_HIGH	High GPIO level
GPIO_VAL_ERR	Invalid GPIO level

## **Function Documentation**
## GpioDisableIrq\(\)
```
int32_t GpioDisableIrq (uint16_t gpio)
```
**Description:**
Disables a GPIO pin interrupt.
You can call this function when you need to temporarily mask a GPIO pin interrupt or cancel an ISR function.
**Parameters:**

Name	Description
gpio	Indicates the GPIO pin number.

**Returns:**
Returns **0** if the GPIO pin interrupt is successfully disabled; returns a negative value otherwise.
## GpioEnableIrq\(\)
```
int32_t GpioEnableIrq (uint16_t gpio)
```
**Description:**
Enables a GPIO pin interrupt.
Before enabling the interrupt, you must call [GpioSetIrq](gpio.md#ga6ea5d16b8d73cb74e36d367f05cb7f6e) to set the ISR function for the GPIO pin.
**Parameters:**

Name	Description
gpio	Indicates the GPIO pin number.

**Returns:**
Returns **0** if the GPIO pin interrupt is successfully enabled; returns a negative value otherwise.
## GpioGetDir\(\)
```
int32_t GpioGetDir (uint16_t gpio, uint16_t * dir )
```
**Description:**
Obtains the input/output direction of a GPIO pin.
**Parameters:**

Name	Description
gpio	Indicates the GPIO pin number.
dir	Indicates the pointer to the obtained input/output direction. For details, see GpioDirType.

**Returns:**
Returns **0** if the GPIO pin direction is successfully obtained; returns a negative value otherwise.
## GpioRead\(\)
```
int32_t GpioRead (uint16_t gpio, uint16_t * val )
```
**Description:**
Reads the level value of a GPIO pin.
Before using this function, you need to call [GpioSetDir](gpio.md#ga5c628216d209fa76c69eca69856bc0ae) to set the GPIO pin direction to input.
**Parameters:**

Name	Description
gpio	Indicates the GPIO pin number.
val	Indicates the pointer to the read level value. For details, see GpioValue.

**Returns:**
Returns **0** if the GPIO pin level value is successfully read; returns a negative value otherwise.
## GpioSetDir\(\)
```
int32_t GpioSetDir (uint16_t gpio, uint16_t dir )
```
**Description:**
Sets the input/output direction for a GPIO pin.
Generally, you can set the direction to input when external level signals need to be read, and set the direction to output when the level signals need to be sent externally.
**Parameters:**

Name	Description
gpio	Indicates the GPIO pin number.
dir	Indicates the direction to set. For details, see GpioDirType.

**Returns:**
Returns **0** if the GPIO pin direction is successfully set; returns a negative value otherwise.
## GpioSetIrq\(\)
```
int32_t GpioSetIrq (uint16_t gpio, uint16_t mode, [GpioIrqFunc](gpio.md#ga8f3b7d0f0aaa1da8117781efe4b1670e) func, void * arg )
```
**Description:**
Sets the ISR function for a GPIO pin.
Before using a GPIO pin as an interrupt, you must call this function to set an ISR function for this GPIO pin, including the ISR parameters and the interrupt trigger mode. After the setting is successful, you also need to call [GpioEnableIrq](gpio.md#gafcf00796a949245d665e672ae0294aee) to enable the interrupt, so that the ISR function can respond correctly.
**Parameters:**

Name	Description
gpio	Indicates the GPIO pin number.
mode	Indicates the interrupt trigger mode. For details, see OSAL_IRQF_TRIGGER_RISING.
func	Indicates the ISR function to set, which is specified by GpioIrqFunc.
arg	Indicates the pointer to the parameters passed to the ISR function.

**Returns:**
Returns **0** if the ISR function of the GPIO pin is successfully set; returns a negative value otherwise.
## GpioUnSetIrq\(\)
```
int32_t GpioUnSetIrq (uint16_t gpio)
```
**Description:**
Cancels the setting of the ISR function for a GPIO pin.
If you do not need the GPIO pin as an interrupt, call this function to cancel the ISR function set via [GpioSetIrq](gpio.md#ga6ea5d16b8d73cb74e36d367f05cb7f6e). Since this ISR function is no longer valid, you are advised to use [GpioDisableIrq](gpio.md#gafa01dc510f26d5aff102d72679920929) to disable the GPIO pin interrupt.
**Parameters:**

Name	Description
gpio	Indicates the GPIO pin number.

**Returns:**
Returns **0** if the ISR function of the GPIO pin is successfully cancelled; returns a negative value otherwise.
## GpioWrite\(\)
```
int32_t GpioWrite (uint16_t gpio, uint16_t val )
```
**Description:**
Writes the level value for a GPIO pin.
Before using this function, you need to call [GpioSetDir](gpio.md#ga5c628216d209fa76c69eca69856bc0ae) to set the GPIO pin direction to output.
**Parameters:**

Name	Description
gpio	Indicates the GPIO pin number.
val	Indicates the level value to be written. For details, see GpioValue.

**Returns:**
Returns **0** if the GPIO pin level value is successfully written; returns a negative value otherwise.