Unit I2C

Return to Unit Reference

For the purpose of this interface a device is the I2C controller attached to the local system and may be either a master or a slave. Since the protocol does not include any form of enumeration or identification the interface does not attempt to represent the devices connected to the bus,any driver written to communicate with a connected I2C device should know (or allow configuration of) the address to read and write to and the specific message format required for that device. The Intel System Management Bus (SMBus) is a variation of the I2C bus and in certain cases the two are compatible with each other.

`I2C_NAME_PREFIX = 'I2C';`	Name prefix for I2C Devices
`I2CSLAVE_NAME_PREFIX = 'I2CSlave';`	Name prefix for I2C Slave Devices

`I2C_TYPE_NONE = 0;`
`I2C_TYPE_MASTER = 1;`
`I2C_TYPE_SLAVE = 2;`

`I2C_TYPE_MAX = 2;`

I2C Type Names
`I2C_TYPE_NAMES:array[I2C_TYPE_NONE..I2C_TYPE_MAX] of String = ('I2C_TYPE_NONE', 'I2C_TYPE_MASTER', 'I2C_TYPE_SLAVE');`

`I2C_STATE_DISABLED = 0;`
`I2C_STATE_ENABLED = 1;`

`I2C_STATE_MAX = 1;`

`I2C_FLAG_NONE = $00000000;`
`I2C_FLAG_SLAVE = $00000001;`	Device is a slave not a master
`I2C_FLAG_10BIT = $00000002;`	Device supports 10bit addressing
`I2C_FLAG_16BIT = $00000004;`	Device supports 16bit addressing

`I2C_LOG_LEVEL_DEBUG = LOG_LEVEL_DEBUG;`	I2C debugging messages
`I2C_LOG_LEVEL_INFO = LOG_LEVEL_INFO;`	I2C informational messages, such as a device being attached or detached
`I2C_LOG_LEVEL_WARN = LOG_LEVEL_WARN;`	I2C warning messages
`I2C_LOG_LEVEL_ERROR = LOG_LEVEL_ERROR;`	I2C error messages
`I2C_LOG_LEVEL_NONE = LOG_LEVEL_NONE;`	No I2C messages

`Flags:LongWord;`	Device flags (eg I2C_FLAG_SLAVE)
`MaxSize:LongWord;`	Maximum supported data transfer size
`MinClock:LongWord;`	Minimum supported clock rate
`MaxClock:LongWord;`	Maximum supported clock rate
`ClockRate:LongWord;`	Current clock rate
`SlaveAddress:Word;`	Current slave address

Device Properties
`Device:TDevice;`	The Device entry for this I2C
I2C Properties
`I2CId:LongWord;`	Unique Id of this I2C in the I2C table
`I2CState:LongWord;`	I2C state (eg I2C_STATE_ENABLED)
`DeviceStart:TI2CDeviceStart;`	A Device specific DeviceStart method implementing the standard I2C device interface (Mandatory)
`DeviceStop:TI2CDeviceStop;`	A Device specific DeviceStop method implementing the standard I2C device interface (Mandatory)
`DeviceRead:TI2CDeviceRead;`	A Device specific DeviceRead method implementing the standard I2C device interface (Mandatory)
`DeviceWrite:TI2CDeviceWrite;`	A Device specific DeviceWrite method implementing the standard I2C device interface (Mandatory)
`DeviceWriteRead:TI2CDeviceWriteRead;`	A Device specific DeviceWriteRead method implementing the standard I2C device interface (Or nil if the default method is suitable)
`DeviceWriteWrite:TI2CDeviceWriteWrite;`	A Device specific DeviceWriteWrite method implementing the standard I2C device interface (Or nil if the default method is suitable)
`DeviceGetRate:TI2CDeviceGetRate;`	A Device specific DeviceGetRate method implementing the standard I2C device interface (Or nil if the default method is suitable)
`DeviceSetRate:TI2CDeviceSetRate;`	A Device specific DeviceSetRate method implementing the standard I2C device interface (Or nil if the default method is suitable)
`DeviceGetAddress:TI2CDeviceGetAddress;`	A Device specific DeviceGetAddress method implementing the standard I2C device interface (Or nil if the default method is suitable)
`DeviceSetAddress:TI2CDeviceSetAddress;`	A Device specific DeviceSetAddress method implementing the standard I2C device interface (Or nil if the default method is suitable)
`DeviceGetProperties:TI2CDeviceGetProperties;`	A Device specific DeviceGetProperties method implementing the standard I2C device interface (Or nil if the default method is suitable)
Statistics Properties
`ReadCount:LongWord;`
`WriteCount:LongWord;`
`ReadErrors:LongWord;`
`WriteErrors:LongWord;`
Driver Properties
`Lock:TMutexHandle;`	Device lock
`Wait:TSemaphoreHandle;`	Read/Write wait event
`ClockRate:LongWord;`	Clock rate (Hz)
`SlaveAddress:Word;`	Slave address
`Properties:TI2CProperties;`	Device properties
Internal Properties
`Prev:PI2CDevice;`	Previous entry in I2C table
`Next:PI2CDevice;`	Next entry in I2C table

I2C	The I2C device to start
Rate	The clock rate to set for the device (0 to use the default rate)
Return	ERROR_SUCCESS if completed or another error code on failure

I2C	The I2C device to stop
Return	ERROR_SUCCESS if completed or another error code on failure

I2C	The I2C device to read from
Address	The slave address to read from (I2C_ADDRESS_INVALID to use the current address)
Buffer	Pointer to a buffer to receive the data
Size	The size of the buffer
Count	The number of bytes read on return
Return	ERROR_SUCCESS if completed or another error code on failure

I2C	The I2C device to write to
Address	The slave address to write to (I2C_ADDRESS_INVALID to use the current address)
Buffer	Pointer to a buffer of data to transmit
Size	The size of the buffer
Count	The number of bytes written on return
Return	ERROR_SUCCESS if completed or another error code on failure

I2C	The I2C device to write to and read from
Address	The slave address to write to (I2C_ADDRESS_INVALID to use the current address)
Initial	Pointer to the initial buffer to transmit
Len	The size of the initial buffer
Data	Pointer to a buffer to receive the data
Size	The size of the data buffer
Count	The number of bytes read on return
Return	ERROR_SUCCESS if completed or another error code on failure
Note	Useful for devices that require a register address specified before a read (eg EEPROM devices)

I2C	The I2C device to get the clock rate from
Return	The clock rate in Hz or 0 on failure

I2C	The I2C device to set the clock rate for
Rate	The clock rate to set in Hz
Return	ERROR_SUCCESS if completed or another error code on failure

I2C	The I2C device to get the slave address from
Return	The slave address or I2C_ADDRESS_INVALID on failure

I2C	The I2C device to set the slave address for
Address	The slave address to set
Return	ERROR_SUCCESS if completed or another error code on failure

I2C	The I2C device to get properties from
Properties	Pointer to a TI2CProperties structure to fill in
Return	ERROR_SUCCESS if completed or another error code on failure
Note	Replaced by I2CDeviceGetProperties for consistency

Size	Size in bytes to allocate for new I2C (Including the I2C entry)
Return	Pointer to new I2C entry or nil if I2C could not be created

I2C	The I2C device to destroy
Return	ERROR_SUCCESS if completed or another error code on failure

I2C	The I2C device to register
Return	ERROR_SUCCESS if completed or another error code on failure

Unit I2C

Contents

Description

Constants

Type definitions

Public variables

Function declarations

Navigation menu

Search

I2C	The I2C device to deregister
Return	ERROR_SUCCESS if completed or another error code on failure

I2CId	The ID number of the I2C device to find
Return	Pointer to I2C device entry or nil if not found

Name	The name of the I2C device to find (eg I2C0)
Return	Pointer to I2C device entry or nil if not found

Description	The description of the I2C to find (eg BCM2837 BSC1 Master I2C)
Return	Pointer to I2C device entry or nil if not found

Callback	The callback function to call for each I2C device in the table
Data	A private data pointer to pass to callback for each I2C device in the table
Return	ERROR_SUCCESS if completed or another error code on failure

Device	The I2C device to notify changes for (Optional, pass nil for all I2C 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)

I2C	The I2C slave to start
Return	ERROR_SUCCESS if completed or another error code on failure

I2C	The I2C slave to stop
Return	ERROR_SUCCESS if completed or another error code on failure

I2C	The I2C slave to read from
Buffer	Pointer to a buffer to receive the data
Size	The size of the buffer
Count	The number of bytes read on return
Return	ERROR_SUCCESS if completed or another error code on failure

I2C	The I2C slave to write to
Buffer	Pointer to a buffer of data to transmit
Size	The size of the buffer
Count	The number of bytes written on return
Return	ERROR_SUCCESS if completed or another error code on failure