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



GPIO specific constants GPIO_*
GPIO_NAME_PREFIX = 'GPIO'; Name prefix for GPIO Devices


GPIO device type GPIO_TYPE_*
GPIO_TYPE_NONE = 0;  
GPIO_TYPE_MAX = 0;  
GPIO device type name
GPIO_TYPE_NAMES:array[GPIO_TYPE_NONE..GPIO_TYPE_MAX] of String = ('GPIO_TYPE_NONE');


GPIO device state GPIO_STATE_*
GPIO_STATE_DISABLED = 0;  
GPIO_STATE_ENABLED = 1;  
 
GPIO_STATE_MAX = 1;  


GPIO device flag GPIO_FLAG_*
GPIO_FLAG_NONE = $00000000;  
GPIO_FLAG_PULL_UP = $00000001; Device supports Pull Up on a pin
GPIO_FLAG_PULL_DOWN = $00000002; Device supports Pull Down on a pin
GPIO_FLAG_TRIGGER_LOW = $00000004; Device supports Trigger on Low level on a pin
GPIO_FLAG_TRIGGER_HIGH = $00000008; Device supports Trigger on High level on a pin
GPIO_FLAG_TRIGGER_RISING = $00000010; Device supports Trigger on Rising edge on a pin
GPIO_FLAG_TRIGGER_FALLING = $00000020; Device supports Trigger on Falling edge on a pin
GPIO_FLAG_TRIGGER_EDGE = $00000040; Device supports Trigger on any edge (Rising or Falling) on a pin
GPIO_FLAG_TRIGGER_ASYNC = $00000080; Device supports Trigger on Asynchronous Rising/Falling edge on a pin


GPIO event flag GPIO_EVENT_FLAG_*
GPIO_EVENT_FLAG_NONE = $00000000;  
GPIO_EVENT_FLAG_REPEAT = $00000001; Event will be repeated until cancelled
GPIO_EVENT_FLAG_INTERRUPT = $00000002; Event will be dispatched by interrupt handler (If applicable)

Caution: Events called by the interrupt handler must obey interrupt rules with regard to locks, memory allocation and latency


GPIO logging GPIO_LOG_*
GPIO_LOG_LEVEL_DEBUG = LOG_LEVEL_DEBUG; GPIO debugging messages
GPIO_LOG_LEVEL_INFO = LOG_LEVEL_INFO; GPIO informational messages, such as a device being attached or detached
GPIO_LOG_LEVEL_WARN = LOG_LEVEL_WARN; GPIO warning messages
GPIO_LOG_LEVEL_ERROR = LOG_LEVEL_ERROR; GPIO error messages
GPIO_LOG_LEVEL_NONE = LOG_LEVEL_NONE; No GPIO messages


Type definitions



GPIO properties

PGPIOProperties = ^TGPIOProperties;

TGPIOProperties = record

Flags:LongWord; Device flags (eg GPIO_FLAG_TRIGGER_HIGH)
PinMin:LongWord;  
PinMax:LongWord;  
PinCount:LongWord;  
FunctionMin:LongWord;  
FunctionMax:LongWord;  
FunctionCount:LongWord;  

GPIO event

PGPIOEvent = ^TGPIOEvent;

TGPIOEvent = record

Pin:PGPIOPin; GPIO Pin this event belongs to
Callback:TGPIOCallback; Callback function to call when trigger occurs
Data:Pointer; Pointer to pass to the callback function when trigger occurs
Timeout:LongWord; Timeout in milliseconds for this callback (or INFINITE for no timeout)
Prev:PGPIOEvent; Previous event in the list
Next:PGPIOEvent; Next event in the list

GPIO pin

PGPIOPin = ^TGPIOPin;

TGPIOPin = record

Note: Forward declared for GPIOEvent
GPIO:PGPIODevice; GPIO device this pin belongs to
Pin:LongWord; Pin number of this pin on the device (May be used by drivers for internal numbering)
Flags:LongWord; Current flags for this pin (eg GPIO_EVENT_FLAG_REPEAT)
Trigger:LongWord; Current trigger value for this pin (or GPIO_TRIGGER_NONE if no triggers current)
Count:LongWord; Count of threads and events waiting for the trigger
Event:TEventHandle; Event for threads waiting for the trigger
Events:PGPIOEvent; List of events waiting for the trigger

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

PGPIODevice = ^TGPIODevice;

TGPIODevice = record

Note: Forward declared for GPIOPin
Device Properties
Device:TDevice; The Device entry for this GPIO
GPIO Properties
GPIOId:LongWord; Unique Id of this GPIO in the GPIO table
GPIOState:LongWord; GPIO state (eg GPIO_STATE_ENABLED)
DeviceStart:TGPIODeviceStart; A Device specific DeviceStart method implementing the standard GPIO device interface (Mandatory)
DeviceStop:TGPIODeviceStop; A Device specific DeviceStop method implementing the standard GPIO device interface (Mandatory)
DeviceRead:TGPIODeviceRead; A Device specific DeviceRead method implementing the standard GPIO device interface (Or nil if the default method is suitable)
DeviceWrite:TGPIODeviceWrite; A Device specific DeviceWrite method implementing the standard GPIO device interface (Or nil if the default method is suitable)
DeviceInputGet:TGPIODeviceInputGet; A Device specific DeviceInputGet method implementing the standard GPIO device interface (Mandatory)
DeviceInputWait:TGPIODeviceInputWait; A Device specific DeviceInputWait method implementing the standard GPIO device interface (Or nil if the operation is not supported)
DeviceInputEvent:TGPIODeviceInputEvent; A Device specific DeviceInputEvent method implementing the standard GPIO device interface (Or nil if the operation is not supported)
DeviceInputCancel:TGPIODeviceInputCancel; A Device specific DeviceInputCancel method implementing the standard GPIO device interface (Or nil if the operation is not supported)
DeviceOutputSet:TGPIODeviceOutputSet; A Device specific DeviceOutputSet method implementing the standard GPIO device interface (Mandatory)
DevicePullGet:TGPIODevicePullGet; A Device specific DevicePullGet method implementing the standard GPIO device interface (Or nil if the operation is not supported)
DevicePullSelect:TGPIODevicePullSelect; A Device specific DevicePullSelect method implementing the standard GPIO device interface (Or nil if the operation is not supported)
DeviceFunctionGet:TGPIODeviceFunctionGet; A Device specific DeviceFunctionGet method implementing the standard GPIO device interface (Or nil if the operation is not supported)
DeviceFunctionSelect:TGPIODeviceFunctionSelect; A Device specific DeviceFunctionSelect method implementing the standard GPIO device interface (Or nil if the operation is not supported)
DeviceGetProperties:TGPIODeviceGetProperties; A Device specific DeviceGetProperties method implementing the standard GPIO device interface (Or nil if the default method is suitable)
Driver Properties
Lock:TMutexHandle; Device lock
Address:Pointer; Device register base address
Pins:array of TGPIOPin; Device pins
Properties:TGPIOProperties; Device properties
Statistics Properties
GetCount:LongWord;  
SetCount:LongWord;  
WaitCount:LongWord;  
EventCount:LongWord;  
Internal Properties
Prev:PGPIODevice; Previous entry in GPIO table
Next:PGPIODevice; Next entry in GPIO table

GPIO pin information

PGPIOInfo = ^TGPIOInfo;

TGPIOInfo = record

Note: Used by other units to pass complete details of a GPIO pin
GPIO:PGPIODevice; Device for this GPIO pin
Pin:LongWord; Pin number (eg GPIO_PIN_59)
Func:LongWord; Function value (or GPIO_FUNCTION_UNKNOWN)
Pull:LongWord; Pull Up/Down value (or GPIO_PULL_UNKNOWN)
Trigger:LongWord; Trigger value (or GPIO_TRIGGER_UNKNOWN)


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

procedure GPIOInit;
Description: To be documented
Note None documented


GPIO functions

function GPIODeviceStart(GPIO:PGPIODevice):LongWord;
Description: Start the specified GPIO device and enable access
GPIO The GPIO device to start
Return ERROR_SUCCESS if completed or another error code on failure


function GPIODeviceStop(GPIO:PGPIODevice):LongWord;
Description: Stop the specified GPIO device and disable access
GPIO The GPIO device to stop
Return ERROR_SUCCESS if completed or another error code on failure


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


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


function GPIODeviceInputGet(GPIO:PGPIODevice; Pin:LongWord):LongWord;
Description: Get the current state of an input pin on the specified GPIO device
GPIO The GPIO device to get from
Pin The pin to get the state for (eg GPIO_PIN_1)
Return The current state (eg GPIO_LEVEL_HIGH) or GPIO_LEVEL_UNKNOWN on failure


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
GPIO The GPIO device to wait for
Pin The pin to wait for the state to change (eg GPIO_PIN_1)
Trigger The trigger event to wait for (eg GPIO_TRIGGER_HIGH)
Timeout Number of milliseconds to wait for the change (INFINITE to wait forever)
Return The state after the change (eg GPIO_LEVEL_HIGH) or GPIO_LEVEL_UNKNOWN on failure or timeout


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
GPIO The GPIO device to schedule the callback for
Pin The pin to schedule the state change for (eg GPIO_PIN_1)
Trigger The trigger event which will cause the function to be called (eg GPIO_TRIGGER_HIGH)
Flags The flags to control the event (eg GPIO_EVENT_FLAG_REPEAT)
Timeout The number of milliseconds before the scheduled trigger expires (INFINITE to never expire)
Callback The function to be called when the trigger occurs
Data A pointer to be pass to the function when the trigger occurs (Optional)
Return ERROR_SUCCESS if the trigger was scheduled successfully or another error code on failure
Note The pin and trigger that caused the event will be passed to the callback function


function GPIODeviceInputCancel(GPIO:PGPIODevice; Pin:LongWord):LongWord;
Description: Cancel a previously scheduled event callback function for an input pin on the specified GPIO device
GPIO The GPIO device to cancel the callback for
Pin The pin to cancel the state change for (eg GPIO_PIN_1)
Return ERROR_SUCCESS if the callback was cancelled successfully or another error code on failure


function GPIODeviceOutputSet(GPIO:PGPIODevice; Pin,Level:LongWord):LongWord;
Description: Set the state of a output pin on the specified GPIO device
GPIO The GPIO device to set for
Pin The pin to set the state for (eg GPIO_PIN_1)
Level The state to set the pin to (eg GPIO_LEVEL_HIGH)
Return ERROR_SUCCESS if completed successfully or another error code on failure


function GPIODeviceLevelGet(GPIO:PGPIODevice; Pin:LongWord):LongWord;
Description: Get the current level (state) of a pin on the specified GPIO device
GPIO The GPIO device to get from
Pin The pin to get the level for (eg GPIO_PIN_1)
Return The current level (eg GPIO_LEVEL_HIGH) or GPIO_LEVEL_UNKNOWN on failure
Note This function is a synonym for GPIODeviceInputGet as in many cases the level can be read from a pin regardless of input or output mode. This may help to make code clearer or easier to understand in some cases.


function GPIODeviceLevelSet(GPIO:PGPIODevice; Pin,Level:LongWord):LongWord;
Description: Set the level (state) of a pin on the specified GPIO device
GPIO The GPIO device to set for
Pin The pin to set the level for (eg GPIO_PIN_1)
Level The level to set the pin to (eg GPIO_LEVEL_HIGH)
Return ERROR_SUCCESS if completed successfully or another error code on failure
Note This function is a synonym for GPIODeviceOutputSet as in many cases the level can be set for a pin regardless of input or output mode. This may help to make code clearer or easier to understand in some cases.


function GPIODevicePullGet(GPIO:PGPIODevice;Pin:LongWord):LongWord;
Description: Get the current pull state of a pin on the specified GPIO device
GPIO The GPIO device to get from
Pin The pin to get the pull state for (eg GPIO_PIN_1)
Return The current pull state of the pin (eg GPIO_PULL_UP) or GPIO_PULL_UNKNOWN on failure


function GPIODevicePullSelect(GPIO:PGPIODevice; Pin,Mode:LongWord):LongWord;
Description: Change the pull state of a pin on the specified GPIO device
GPIO The GPIO device to set for
Pin The pin to change the pull state for (eg GPIO_PIN_1)
Mode The pull state to set for the pin (eg GPIO_PULL_UP)
Return ERROR_SUCCESS if completed successfully or another error code on failure


function GPIODeviceFunctionGet(GPIO:PGPIODevice; Pin:LongWord):LongWord;
Description: Get the current function of a pin on the specified GPIO device
GPIO The GPIO device to get from
Pin The pin to get the function for (eg GPIO_PIN_1)
Return The current function of the pin (eg GPIO_FUNCTION_IN) or GPIO_FUNCTION_UNKNOWN on failure


function GPIODeviceFunctionSelect(GPIO:PGPIODevice; Pin,Mode:LongWord):LongWord;
Description: Change the function of a pin on the specified GPIO device
GPIO The GPIO device to set for
Pin The pin to change the function for (eg GPIO_PIN_1)
Mode The function to set for the pin (eg GPIO_FUNCTION_OUT)
Return ERROR_SUCCESS if completed successfully or another error code on failure


function GPIODeviceProperties(GPIO:PGPIODevice; Properties:PGPIOProperties):LongWord; inline;
Description: Get the properties for the specified GPIO device
GPIO The GPIO device to get properties from
Properties Pointer to a TGPIOProperties structure to fill in
Return ERROR_SUCCESS if completed or another error code on failure
Note Replaced by GPIODeviceGetProperties for consistency


function GPIODeviceGetProperties(GPIO:PGPIODevice; Properties:PGPIOProperties):LongWord;
Description: Get the properties for the specified GPIO device
GPIO The GPIO device to get properties from
Properties Pointer to a TGPIOProperties structure to fill in
Return ERROR_SUCCESS if completed or another error code on failure


function GPIODeviceCreate:PGPIODevice;
Description: Create a new GPIO entry
Return Pointer to new GPIO entry or nil if GPIO could not be created


function GPIODeviceCreateEx(Size:LongWord):PGPIODevice;
Description: Create a new GPIO entry
Size Size in bytes to allocate for new GPIO (Including the GPIO entry)
Return Pointer to new GPIO entry or nil if GPIO could not be created


function GPIODeviceDestroy(GPIO:PGPIODevice):LongWord;
Description: Destroy an existing GPIO entry
GPIO The GPIO device to destroy
Return ERROR_SUCCESS if completed or another error code on failure


function GPIODeviceRegister(GPIO:PGPIODevice):LongWord;
Description: Register a new GPIO in the GPIO table
GPIO The GPIO device to register
Return ERROR_SUCCESS if completed or another error code on failure


function GPIODeviceDeregister(GPIO:PGPIODevice):LongWord;
Description: Deregister a GPIO in the GPIO table
GPIO The GPIO device to deregister
Return ERROR_SUCCESS if completed or another error code on failure


function GPIODeviceFind(GPIOId:LongWord):PGPIODevice;
Description: Find a GPIO device by ID in the GPIO table
GPIOId The ID number of the GPIO device to find
Return Pointer to GPIO device entry or nil if not found


function GPIODeviceFindByName(const Name:String):PGPIODevice; inline;
Description: Find a GPIO device by name in the GPIO table
Name The name of the GPIO to find (eg GPIO0)
Return Pointer to GPIO device entry or nil if not found


function GPIODeviceFindByDescription(const Description:String):PGPIODevice; inline;
Description: Find a GPIO device by description in the GPIO table
Description The description of the GPIO to find (eg BCM2836 GPIO)
Return Pointer to GPIO device entry or nil if not found


function GPIODeviceEnumerate(Callback:TGPIOEnumerate; Data:Pointer):LongWord;
Description: Enumerate all GPIO devices in the GPIO table
Callback The callback function to call for each GPIO in the table
Data A private data pointer to pass to callback for each GPIO in the table
Note ERROR_SUCCESS if completed or another error code on failure


function GPIODeviceNotification(GPIO:PGPIODevice; Callback:TGPIONotification; Data:Pointer; Notification,Flags:LongWord):LongWord;
Description: Register a notification for GPIO device changes
GPIO The GPIO device to notify changes for (Optional, pass nil for all GPIO devices)
Callback The function to call when a notification event occurs
Data A private data pointer to pass to callback when a notification event occurs
Notification The events to register for notification of (eg DEVICE_NOTIFICATION_REGISTER)
Flags The flags to control the notification (eg NOTIFIER_FLAG_WORKER)


RTL GPIO functions

function SysGPIOAvailable:Boolean;
Description: Check if a GPIO device is available
Note None documented


function SysGPIOInputGet(Pin:LongWord):LongWord;
Description: Get the current state of a GPIO input pin
Pin The pin to get the state for (eg GPIO_PIN_1)
Return The current state (eg GPIO_LEVEL_HIGH) or GPIO_LEVEL_UNKNOWN on failure


function SysGPIOInputWait(Pin,Trigger,Timeout:LongWord):LongWord;
Description: Wait for the state of a GPIO input pin to change
Pin The pin to wait for the state to change (eg GPIO_PIN_1)
Trigger The trigger event to wait for (eg GPIO_TRIGGER_HIGH)
Timeout Number of milliseconds to wait for the change (INFINITE to wait forever)
Return The state after the change (eg GPIO_LEVEL_HIGH) or GPIO_LEVEL_UNKNOWN on failure or timeout


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
Pin The pin to schedule the state change for (eg GPIO_PIN_1)
Trigger The trigger event which will cause the function to be called (eg GPIO_TRIGGER_HIGH)
Timeout The number of milliseconds before the scheduled trigger expires (INFINITE to never expire)
Callback The function to be called when the trigger occurs
Data A pointer to be pass to the function when the trigger occurs (Optional)
Return ERROR_SUCCESS if the trigger was scheduled successfully or another error code on failure
Note The pin and trigger that caused the event will be passed to the callback function


function SysGPIOOutputSet(Pin,Level:LongWord):LongWord; 
Description: Set the state of a GPIO output pin
Pin The pin to set the state for (eg GPIO_PIN_1)
Level The state to set the pin to (eg GPIO_LEVEL_HIGH)
Return ERROR_SUCCESS if completed successfully or another error code on failure


function SysGPIOPullGet(Pin:LongWord):LongWord;
Description: Get the current pull state of a GPIO pin
Pin The pin to get the pull state for (eg GPIO_PIN_1)
Return The current pull state of the pin (eg GPIO_PULL_UP) or GPIO_PULL_UNKNOWN on failure


function SysGPIOPullSelect(Pin,Mode:LongWord):LongWord;
Description: Change the pull state of a GPIO pin
Pin The pin to change the pull state for (eg GPIO_PIN_1)
Mode The pull state to set for the pin (eg GPIO_PULL_UP)
Return ERROR_SUCCESS if completed successfully or another error code on failure


function SysGPIOFunctionGet(Pin:LongWord):LongWord;
Description: Get the current function of a GPIO pin
Pin The pin to get the function for (eg GPIO_PIN_1)
Return The current function of the pin (eg GPIO_FUNCTION_IN) or GPIO_FUNCTION_UNKNOWN on failure


function SysGPIOFunctionSelect(Pin,Mode:LongWord):LongWord;
Description: Change the function of a GPIO pin
Pin The pin to change the function for (eg GPIO_PIN_1)
Mode The function to set for the pin (eg GPIO_FUNCTION_OUT)
Return ERROR_SUCCESS if completed successfully or another error code on failure


GPIO helper functions

function GPIOGetCount:LongWord;
Description: Get the current GPIO count
Note None documented


function GPIODeviceGetDefault:PGPIODevice;
Description: Get the current default GPIO device
Note None documented


function GPIODeviceSetDefault(GPIO:PGPIODevice):LongWord;
Description: Set the current default GPIO device
Note None documented


function GPIODeviceCheck(GPIO:PGPIODevice):PGPIODevice;
Description: Check if the supplied GPIO is in the GPIO table
Note None documented


function GPIOTypeToString(GPIOType:LongWord):String;
Description: Convert a GPIO type value to a string
Note None documented


function GPIOStateToString(GPIOState:LongWord):String;
Description: Convert a GPIO state value to a string
Note None documented


function GPIODeviceCreateEvent(GPIO:PGPIODevice; Pin:PGPIOPin; Callback:TGPIOCallback; Data:Pointer; Timeout:LongWord):PGPIOEvent;
Description: Create a new event using the supplied parameters
Note Event must be registered by calling GPIODeviceRegisterEvent

Caller must hold the GPIO device lock


function GPIODeviceDestroyEvent(GPIO:PGPIODevice; Event:PGPIOEvent):LongWord;
Description: Destroy an existing event
Note Event must be deregistered first by calling GPIODeviceDeregisterEvent

Caller must hold the GPIO device lock


function GPIODeviceRegisterEvent(GPIO:PGPIODevice; Pin:PGPIOPin; Event:PGPIOEvent):LongWord;
Description: Register an event in the event list of the supplied Pin
Note Event must be created by calling GPIODeviceCreateEvent

Caller must hold the GPIO device lock


function GPIODeviceDeregisterEvent(GPIO:PGPIODevice;Pin:PGPIOPin;Event:PGPIOEvent):LongWord;
Description: Deregister an event in the event list of the supplied Pin
Note Event must be destroyed by calling GPIODeviceDestroyEvent

Caller must hold the GPIO device lock


procedure GPIOLog(Level:LongWord; GPIO:PGPIODevice; const AText:String);
Description: To be documented
Note None documented


procedure GPIOLogInfo(GPIO:PGPIODevice; const AText:String); inline;
Description: To be documented
Note None documented


procedure GPIOLogWarn(GPIO:PGPIODevice; const AText:String); inline;
Description: To be documented
Note None documented


procedure GPIOLogError(GPIO:PGPIODevice; const AText:String); inline;
Description: To be documented
Note None documented


procedure GPIOLogDebug(GPIO:PGPIODevice; const AText:String); inline;
Description: To be documented
Note None documented


function GPIOPinToString(Pin:LongWord):String;
Description: To be documented
Note None documented


function GPIOLevelToString(Level:LongWord):String;
Description: To be documented
Note None documented


function GPIOTriggerToString(Trigger:LongWord):String;
Description: To be documented
Note None documented


function GPIOPullToString(Value:LongWord):String;
Description: To be documented
Note None documented


function GPIOFunctionToString(Value:LongWord):String;
Description: To be documented
Note None documented


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