Unit GPIO

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Description


Ultibo GPIO Interface unit

GPIO devices represent the external or internal pins available on most system on chip (SoC) devices to provide control and interfacing capabilities for both hardware and software.

This unit maintains pin numbering exactly as per the SoC documentation but abstracts other features such as alternate function selects to avoid exposing chip specific values via the API.

Not all GPIO devices support the same feature set so the GPIODeviceGetProperties function returns a structure which describes the number of pins as well as minimum and maximum pin numbers along with a set of flags that indicate what functionality is supported by the device.

Multiple GPIO devices can be accommodated, each one is registered with this unit when the driver for the device is loaded and initialized. This unit includes functions for enumerating the devices that are available and each function takes a GPIODevice parameter to allow specifying the exact device to control.

Simplified versions of many of the functions in this unit are provided in the Platform unit to allow control of the default GPIO device and in cases where there is only one device registered these functions will provide most of the capability required.

Constants



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GPIO specific constants GPIO_*


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GPIO device type GPIO_TYPE_*


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GPIO device state GPIO_STATE_*


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GPIO device flag GPIO_FLAG_*


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GPIO event flag GPIO_EVENT_FLAG_*


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GPIO logging GPIO_LOG_*


Type definitions



GPIO properties

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PGPIOProperties = ^TGPIOProperties;

TGPIOProperties = record

GPIO event

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PGPIOEvent = ^TGPIOEvent;

TGPIOEvent = record

GPIO pin

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PGPIOPin = ^TGPIOPin;

TGPIOPin = record

GPIO enumeration callback

TGPIOEnumerate = function(GPIO:PGPIODevice; Data:Pointer):LongWord;

GPIO notification callback

TGPIONotification = function(Device:PDevice; Data:Pointer; Notification:LongWord):LongWord;

GPIO device start

TGPIODeviceStart = function(GPIO:PGPIODevice):LongWord;

GPIO device stop

TGPIODeviceStop = function(GPIO:PGPIODevice):LongWord;

GPIO device read

TGPIODeviceRead = function(GPIO:PGPIODevice; Reg:LongWord):LongWord;

GPIO device write

TGPIODeviceWrite = procedure(GPIO:PGPIODevice; Reg,Value:LongWord);

GPIO device input get

TGPIODeviceInputGet = function(GPIO:PGPIODevice; Pin:LongWord):LongWord;

GPIO device input wait

TGPIODeviceInputWait = function(GPIO:PGPIODevice; Pin,Trigger,Timeout:LongWord):LongWord;

GPIO device input event

TGPIODeviceInputEvent = function(GPIO:PGPIODevice; Pin,Trigger,Flags,Timeout:LongWord; Callback:TGPIOCallback; Data:Pointer):LongWord;

GPIO device input cancel

TGPIODeviceInputCancel = function(GPIO:PGPIODevice; Pin:LongWord):LongWord;

GPIO device output set

TGPIODeviceOutputSet = function(GPIO:PGPIODevice; Pin,Level:LongWord):LongWord;

GPIO device pull get

TGPIODevicePullGet = function(GPIO:PGPIODevice; Pin:LongWord):LongWord;

GPIO device pull select

TGPIODevicePullSelect = function(GPIO:PGPIODevice; Pin,Mode:LongWord):LongWord;

GPIO device function get

TGPIODeviceFunctionGet = function(GPIO:PGPIODevice; Pin:LongWord):LongWord;

GPIO device function select

TGPIODeviceFunctionSelect = function(GPIO:PGPIODevice; Pin,Mode:LongWord):LongWord;

GPIO device get properties

TGPIODeviceGetProperties = function(GPIO:PGPIODevice; Properties:PGPIOProperties):LongWord;

GPIO device

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PGPIODevice = ^TGPIODevice;

TGPIODevice = record

GPIO pin information

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PGPIOInfo = ^TGPIOInfo;

TGPIOInfo = record


Public variables



GPIO logging

GPIO_DEFAULT_LOG_LEVEL:LongWord = GPIO_LOG_LEVEL_DEBUG; Minimum level for GPIO messages. Only messages with level greater than or equal to this will be printed.
GPIO_LOG_ENABLED:Boolean;


Function declarations



Initialization functions

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procedure GPIOInit;
Description: To be documented


GPIO functions

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function GPIODeviceStart(GPIO:PGPIODevice):LongWord;
Description: Start the specified GPIO device and enable access


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function GPIODeviceStop(GPIO:PGPIODevice):LongWord;
Description: Stop the specified GPIO device and disable access


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function GPIODeviceRead(GPIO:PGPIODevice; Reg:LongWord):LongWord;
Description: Perform a direct read from a register of the specified GPIO device


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procedure GPIODeviceWrite(GPIO:PGPIODevice; Reg,Value:LongWord);
Description: Perform a direct write to a register of the specified GPIO device


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function GPIODeviceInputGet(GPIO:PGPIODevice; Pin:LongWord):LongWord;
Description: Get the current state of an input pin on the specified GPIO device


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function GPIODeviceInputWait(GPIO:PGPIODevice; Pin,Trigger,Timeout:LongWord):LongWord;
Description: Wait for the state of a input pin to change on the specified GPIO device


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function GPIODeviceInputEvent(GPIO:PGPIODevice; Pin,Trigger,Flags,Timeout:LongWord; Callback:TGPIOCallback; Data:Pointer):LongWord;
Description: Schedule a function to be called when the state of a input pin changes on the specified GPIO device


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function GPIODeviceInputCancel(GPIO:PGPIODevice; Pin:LongWord):LongWord;
Description: Cancel a previously scheduled event callback function for an input pin on the specified GPIO device


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function GPIODeviceOutputSet(GPIO:PGPIODevice; Pin,Level:LongWord):LongWord;
Description: Set the state of a output pin on the specified GPIO device


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function GPIODeviceLevelGet(GPIO:PGPIODevice; Pin:LongWord):LongWord;
Description: Get the current level (state) of a pin on the specified GPIO device


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function GPIODeviceLevelSet(GPIO:PGPIODevice; Pin,Level:LongWord):LongWord;
Description: Set the level (state) of a pin on the specified GPIO device


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function GPIODevicePullGet(GPIO:PGPIODevice;Pin:LongWord):LongWord;
Description: Get the current pull state of a pin on the specified GPIO device


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function GPIODevicePullSelect(GPIO:PGPIODevice; Pin,Mode:LongWord):LongWord;
Description: Change the pull state of a pin on the specified GPIO device


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function GPIODeviceFunctionGet(GPIO:PGPIODevice; Pin:LongWord):LongWord;
Description: Get the current function of a pin on the specified GPIO device


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function GPIODeviceFunctionSelect(GPIO:PGPIODevice; Pin,Mode:LongWord):LongWord;
Description: Change the function of a pin on the specified GPIO device


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function GPIODeviceProperties(GPIO:PGPIODevice; Properties:PGPIOProperties):LongWord; inline;
Description: Get the properties for the specified GPIO device


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function GPIODeviceGetProperties(GPIO:PGPIODevice; Properties:PGPIOProperties):LongWord;
Description: Get the properties for the specified GPIO device


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function GPIODeviceCreate:PGPIODevice;
Description: Create a new GPIO entry


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function GPIODeviceCreateEx(Size:LongWord):PGPIODevice;
Description: Create a new GPIO entry


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function GPIODeviceDestroy(GPIO:PGPIODevice):LongWord;
Description: Destroy an existing GPIO entry


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function GPIODeviceRegister(GPIO:PGPIODevice):LongWord;
Description: Register a new GPIO in the GPIO table


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function GPIODeviceDeregister(GPIO:PGPIODevice):LongWord;
Description: Deregister a GPIO in the GPIO table


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function GPIODeviceFind(GPIOId:LongWord):PGPIODevice;
Description: Find a GPIO device by ID in the GPIO table


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function GPIODeviceFindByName(const Name:String):PGPIODevice; inline;
Description: Find a GPIO device by name in the GPIO table


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function GPIODeviceFindByDescription(const Description:String):PGPIODevice; inline;
Description: Find a GPIO device by description in the GPIO table


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function GPIODeviceEnumerate(Callback:TGPIOEnumerate; Data:Pointer):LongWord;
Description: Enumerate all GPIO devices in the GPIO table


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function GPIODeviceNotification(GPIO:PGPIODevice; Callback:TGPIONotification; Data:Pointer; Notification,Flags:LongWord):LongWord;
Description: Register a notification for GPIO device changes


RTL GPIO functions

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function SysGPIOAvailable:Boolean;
Description: Check if a GPIO device is available


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function SysGPIOInputGet(Pin:LongWord):LongWord;
Description: Get the current state of a GPIO input pin


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function SysGPIOInputWait(Pin,Trigger,Timeout:LongWord):LongWord;
Description: Wait for the state of a GPIO input pin to change


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function SysGPIOInputEvent(Pin,Trigger,Timeout:LongWord; Callback:TGPIOCallback; Data:Pointer):LongWord;
Description: Schedule a function to be called when the state of a GPIO input pin changes


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function SysGPIOOutputSet(Pin,Level:LongWord):LongWord; 
Description: Set the state of a GPIO output pin


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function SysGPIOPullGet(Pin:LongWord):LongWord;
Description: Get the current pull state of a GPIO pin


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function SysGPIOPullSelect(Pin,Mode:LongWord):LongWord;
Description: Change the pull state of a GPIO pin


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function SysGPIOFunctionGet(Pin:LongWord):LongWord;
Description: Get the current function of a GPIO pin


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function SysGPIOFunctionSelect(Pin,Mode:LongWord):LongWord;
Description: Change the function of a GPIO pin


GPIO helper functions

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function GPIOGetCount:LongWord;
Description: Get the current GPIO count


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function GPIODeviceGetDefault:PGPIODevice;
Description: Get the current default GPIO device


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function GPIODeviceSetDefault(GPIO:PGPIODevice):LongWord;
Description: Set the current default GPIO device


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function GPIODeviceCheck(GPIO:PGPIODevice):PGPIODevice;
Description: Check if the supplied GPIO is in the GPIO table


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function GPIOTypeToString(GPIOType:LongWord):String;
Description: Convert a GPIO type value to a string


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function GPIOStateToString(GPIOState:LongWord):String;
Description: Convert a GPIO state value to a string


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function GPIODeviceCreateEvent(GPIO:PGPIODevice; Pin:PGPIOPin; Callback:TGPIOCallback; Data:Pointer; Timeout:LongWord):PGPIOEvent;
Description: Create a new event using the supplied parameters


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function GPIODeviceDestroyEvent(GPIO:PGPIODevice; Event:PGPIOEvent):LongWord;
Description: Destroy an existing event


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function GPIODeviceRegisterEvent(GPIO:PGPIODevice; Pin:PGPIOPin; Event:PGPIOEvent):LongWord;
Description: Register an event in the event list of the supplied Pin


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function GPIODeviceDeregisterEvent(GPIO:PGPIODevice;Pin:PGPIOPin;Event:PGPIOEvent):LongWord;
Description: Deregister an event in the event list of the supplied Pin


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procedure GPIOLog(Level:LongWord; GPIO:PGPIODevice; const AText:String);
Description: To be documented


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procedure GPIOLogInfo(GPIO:PGPIODevice; const AText:String); inline;
Description: To be documented


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procedure GPIOLogWarn(GPIO:PGPIODevice; const AText:String); inline;
Description: To be documented


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procedure GPIOLogError(GPIO:PGPIODevice; const AText:String); inline;
Description: To be documented


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procedure GPIOLogDebug(GPIO:PGPIODevice; const AText:String); inline;
Description: To be documented


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function GPIOPinToString(Pin:LongWord):String;
Description: To be documented


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function GPIOLevelToString(Level:LongWord):String;
Description: To be documented


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function GPIOTriggerToString(Trigger:LongWord):String;
Description: To be documented


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function GPIOPullToString(Value:LongWord):String;
Description: To be documented


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function GPIOFunctionToString(Value:LongWord):String;
Description: To be documented


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