Difference between revisions of "Unit GPIO"
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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. | 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. | ||
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Return to [[Unit_Reference|Unit Reference]] | Return to [[Unit_Reference|Unit Reference]] | ||
Revision as of 01:19, 19 August 2016
Return to Unit Reference
Description
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 GPIODeviceProperties 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 accomodated, 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
To be documented
Type definitions
To be documented
Public variables
To be documented
Function declarations
Initialization functions
procedure GPIOInit;
Description: To be documented
| Note | To be documented |
|---|
GPIO functions
function GPIODeviceStart(GPIO:PGPIODevice):LongWord;
Description: To be documented
| Note | To be documented |
|---|
function GPIODeviceStop(GPIO:PGPIODevice):LongWord;
Description: To be documented
| Note | To be documented |
|---|
function GPIODeviceRead(GPIO:PGPIODevice; Reg:LongWord):LongWord;
Description: To be documented
| Note | To be documented |
|---|
procedure GPIODeviceWrite(GPIO:PGPIODevice; Reg,Value:LongWord);
Description: To be documented
| Note | To be documented |
|---|
function GPIODeviceInputGet(GPIO:PGPIODevice; Pin:LongWord):LongWord;
Description: To be documented
| Note | To be documented |
|---|
function GPIODeviceInputWait(GPIO:PGPIODevice; Pin,Trigger,Timeout:LongWord):LongWord;
Description: To be documented
| Note | To be documented |
|---|
function GPIODeviceInputEvent(GPIO:PGPIODevice; Pin,Trigger,Flags,Timeout:LongWord; Callback:TGPIOCallback; Data:Pointer):LongWord;
Description: To be documented
| Note | To be documented |
|---|
function GPIODeviceInputCancel(GPIO:PGPIODevice; Pin:LongWord):LongWord;
Description: To be documented
| Note | To be documented |
|---|
function GPIODeviceOutputSet(GPIO:PGPIODevice; Pin,Level:LongWord):LongWord;
Description: To be documented
| Note | To be documented |
|---|
function GPIODevicePullGet(GPIO:PGPIODevice;Pin:LongWord):LongWord;
Description: To be documented
| Note | To be documented |
|---|
function GPIODevicePullSelect(GPIO:PGPIODevice; Pin,Mode:LongWord):LongWord;
Description: To be documented
| Note | To be documented |
|---|
function GPIODeviceFunctionGet(GPIO:PGPIODevice; Pin:LongWord):LongWord;
Description: To be documented
| Note | To be documented |
|---|
function GPIODeviceFunctionSelect(GPIO:PGPIODevice; Pin,Mode:LongWord):LongWord;
Description: To be documented
| Note | To be documented |
|---|
function GPIODeviceProperties(GPIO:PGPIODevice; Properties:PGPIOProperties):LongWord;
Description: To be documented
| Note | To be documented |
|---|
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
| Note | To be documented |
|---|
function GPIODeviceRegister(GPIO:PGPIODevice):LongWord;
Description: Register a new GPIO in the GPIO table
| Note | To be documented |
|---|
function GPIODeviceDeregister(GPIO:PGPIODevice):LongWord;
Description: Deregister a GPIO in the GPIO table
| Note | To be documented |
|---|
function GPIODeviceFind(GPIOId:LongWord):PGPIODevice;
Description: To be documented
| Note | To be documented |
|---|
function GPIODeviceFindByName(const Name:String):PGPIODevice; inline;
Description: To be documented
| Note | To be documented |
|---|
function GPIODeviceFindByDescription(const Description:String):PGPIODevice; inline;
Description: To be documented
| Note | To be documented |
|---|
function GPIODeviceEnumerate(Callback:TGPIOEnumerate; Data:Pointer):LongWord;
Description: To be documented
| Note | To be documented |
|---|
function GPIODeviceNotification(GPIO:PGPIODevice; Callback:TGPIONotification; Data:Pointer; Notification,Flags:LongWord):LongWord;
Description: To be documented
| Note | To be documented |
|---|
RTL GPIO functions
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; inline;
Description: Get the current GPIO count
| Note | To be documented |
|---|
function GPIODeviceGetDefault:PGPIODevice; inline;
Description: Get the current default GPIO device
| Note | To be documented |
|---|
function GPIODeviceSetDefault(GPIO:PGPIODevice):LongWord;
Description: Set the current default GPIO device
| Note | To be documented |
|---|
function GPIODeviceCheck(GPIO:PGPIODevice):PGPIODevice;
Description: Check if the supplied GPIO is in the GPIO table
| Note | To be 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 | To be documented |
|---|
procedure GPIOLogInfo(GPIO:PGPIODevice; const AText:String);
Description: To be documented
| Note | To be documented |
|---|
procedure GPIOLogError(GPIO:PGPIODevice; const AText:String);
Description: To be documented
| Note | To be documented |
|---|
procedure GPIOLogDebug(GPIO:PGPIODevice; const AText:String);
Description: To be documented
| Note | To be documented |
|---|
function GPIOPinToString(Pin:LongWord):String;
Description: To be documented
| Note | To be documented |
|---|
function GPIOLevelToString(Level:LongWord):String;
Description: To be documented
| Note | To be documented |
|---|
function GPIOTriggerToString(Trigger:LongWord):String;
Description: To be documented
| Note | To be documented |
|---|
function GPIOPullToString(Value:LongWord):String;
Description: To be documented
| Note | To be documented |
|---|
function GPIOFunctionToString(Value:LongWord):String;
Description: To be documented
| Note | To be documented |
|---|
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