Detailed Description

Inter-Integrated Circuit (I2C) Slave Driver.

Overview

The I2C Slave driver allows you to send and recieve I2C transfers. This driver complements the I2C.h driver which operates as an I2C master.

Usage

This documentation provides a basic usage summary and a set of examples in the form of commented code fragments. Detailed descriptions of the APIs are provided in subsequent sections.

Synopsis

// Import I2C Slave Driver definitions
#include <ti/drivers/I2CSlave.h>
// Define name for an index of an I2C Slave
#define MASTER_BUS 0
// One-time init of I2C driver
I2CSlave_init();
// initialize optional I2C parameters
I2CSlave_Params params;
I2CSlave_Params_init(&params);
params.transferMode = I2CSLAVE_MODE_BLOCKING;
// Open I2C Slavefor usage
I2CSlave_Handle i2cHandle = I2CSlave_open(MASTER_BUS, &params);
// Wait for a write from an I2C master device
I2CSlave_read(i2cHandle, buffer, 4);
// Write to the I2C master device
I2CSlave_write(i2cHandle, buffer, 2);
// Close I2C
I2CSlave_close(i2cHandle);

Examples

Opening the driver

// Define name for an index of an I2C Slave
#define MASTER_BUS 0
I2CSlave_Handle handle;
I2CSlave_Params params;
// One-time init of I2C Slave driver
I2CSlave_init();
I2CSlave_Params_init(&params);
params.transferMode  = I2CSLAVE_MODE_CALLBACK;
params.transferCallbackFxn = callbackFxn;
handle = I2CSlave_open(0, &params);
if (handle == NULL) {
    // I2C Slave failed to open
    while (1) {}
}

Transferring data

status = I2CSlave_read(handle, buffer, 5)
if (status == false) {
    //Unsuccessful I2CSlave read
}
status = I2CSlave_write(handle, buffer, 3);
if (status == false) {
    //Unsuccessful I2CSlave write
}

Configuration

Refer to the Driver's Configuration section for driver configuration information.

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

Include dependency graph for I2CSlave.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Data Structures
struct	I2CSlave_Params
	I2CSlave parameters used with I2CSlave_open(). More...

struct	I2CSlave_FxnTable
	The definition of a I2CSlave function table that contains the required set of functions to control a specific I2CSlave driver implementation. More...

struct	I2CSlave_Config_
	I2C Slave driver's custom configuration structure. More...

Macros
#define	I2CSLAVE_CMD_RESERVED (32)

#define	I2CSLAVE_STATUS_RESERVED (-32)

#define	I2CSLAVE_STATUS_SUCCESS (0)
	Successful status code returned by I2CSlave_control(). More...

#define	I2CSLAVE_STATUS_ERROR (-1)
	Generic error status code returned by I2CSlave_control(). More...

#define	I2CSLAVE_STATUS_UNDEFINEDCMD (-2)
	An error status code returned by I2CSlave_control() for undefined command codes. More...

Typedefs
typedef struct I2CSlave_Config_ *	I2CSlave_Handle
	A handle that is returned from a I2CSlave_open() call. More...

typedef void(*	I2CSlave_CallbackFxn) (I2CSlave_Handle handle, bool status)
	The definition of a callback function. More...

typedef struct I2CSlave_Config_	I2CSlave_Config
	I2C Slave driver's custom configuration structure. More...

Enumerations
enum	I2CSlave_TransferMode { I2CSLAVE_MODE_BLOCKING, I2CSLAVE_MODE_CALLBACK }
	Return behavior of I2CSlave_write() and I2CSlave_read() specified in the I2CSlave_Params. More...

Functions
void	I2CSlave_close (I2CSlave_Handle handle)
	Function to close an I2CSlave driver instance. More...

int_fast16_t	I2CSlave_control (I2CSlave_Handle handle, uint_fast16_t cmd, void *arg)
	Function performs implementation specific features on a driver instance. More...

void	I2CSlave_init (void)
	Function to initialize the I2C Slave driver. More...

I2CSlave_Handle	I2CSlave_open (uint_least8_t index, I2CSlave_Params *params)
	Function to initialize the I2CSlave peripheral. More...

void	I2CSlave_Params_init (I2CSlave_Params *params)
	Initialize an I2CSlave_Params structure to its default values. More...

bool	I2CSlave_read (I2CSlave_Handle handle, void *buffer, size_t size)
	Perform an I2C read from an I2C master. More...

bool	I2CSlave_write (I2CSlave_Handle handle, const void *buffer, size_t size)
	Perform an I2C write to an I2C master. More...

Typedef Documentation

§ I2CSlave_Handle

typedef struct I2CSlave_Config_* I2CSlave_Handle

A handle that is returned from a I2CSlave_open() call.

§ I2CSlave_CallbackFxn

typedef void(* I2CSlave_CallbackFxn) (I2CSlave_Handle handle, bool status)

The definition of a callback function.

When operating in I2CSLAVE_MODE_CALLBACK, the callback function is called when a transfer completes. The application is responsible for declaring an I2CSlave_CallbackFxn function and providing a pointer in I2CSlave_Params.transferCallbackFxn.

Warning: The callback function is called from an interrupt context.

Parameters

[out]	handle	I2CSlave_Handle used with the initial call to I2CSlave_read() or I2CSlave_write()
[out]	status	Boolean indicating if the I2C transfer was successful. If `true`, the transfer was successful. If `false`, the transfer failed.

§ I2CSlave_Config

typedef struct I2CSlave_Config_ I2CSlave_Config

I2C Slave driver's custom configuration structure.

See also: I2CSlave_init(); I2CSlave_open()

Enumeration Type Documentation

§ I2CSlave_TransferMode

enum I2CSlave_TransferMode

Return behavior of I2CSlave_write() and I2CSlave_read() specified in the I2CSlave_Params.

See also: I2CSlave_Params

Enumerator
I2CSLAVE_MODE_BLOCKING
I2CSLAVE_MODE_CALLBACK

Function Documentation

§ I2CSlave_close()

void I2CSlave_close ( I2CSlave_Handle handle )

Function to close an I2CSlave driver instance.

Precondition: I2CSlave_open() has to be called first.

Parameters

[in] handle An I2CSlave_Handle returned from I2CSlave_open()

§ I2CSlave_control()

int_fast16_t I2CSlave_control	(	I2CSlave_Handle	handle,
		uint_fast16_t	cmd,
		void *	arg
	)

Function performs implementation specific features on a driver instance.

Precondition: I2CSlave_open() has to be called first.

Parameters

[in]	handle	An I2CSlave_Handle returned from I2CSlave_open()
[in]	cmd	A command value defined by the device specific implementation
[in]	arg	An optional R/W (read/write) argument that is accompanied with `cmd`

Returns: Implementation specific return codes. Negative values indicate unsuccessful operations.

Return values

I2CSLAVE_STATUS_UNDEFINEDCMD The cmd value is not supported by the device specific implementation.

§ I2CSlave_init()

void I2CSlave_init ( void )

Function to initialize the I2C Slave driver.

This function must also be called before any other I2CSlave driver APIs.

§ I2CSlave_open()

I2CSlave_Handle I2CSlave_open	(	uint_least8_t	index,
		I2CSlave_Params *	params
	)

Function to initialize the I2CSlave peripheral.

Function to initialize the I2CSlave peripheral specified by the particular index value.

Precondition: I2CSlave_init() has been called

Parameters

[in]	index	Index in the `I2CSlave_Config`[] array.
[in]	params	Pointer to an initialized I2CSlave_Params structure. If NULL, the default I2CSlave_Params values are used.

Returns: An I2CSlave_Handle on success or NULL on error.

See also: I2CSlave_init(); I2CSlave_close()

§ I2CSlave_Params_init()

void I2CSlave_Params_init ( I2CSlave_Params * params )

Initialize an I2CSlave_Params structure to its default values.

Parameters

[in] params A pointer to an I2CSlave_Params structure.

Defaults values are:

I2CSlave_Params.transferMode = I2CSLAVE_MODE_BLOCKING
I2CSlave_Params.transferCallbackFxn = NULL
I2CSlave_Params.custom = NULL

See also: I2CSlave_open()

§ I2CSlave_read()

bool I2CSlave_read	(	I2CSlave_Handle	handle,
		void *	buffer,
		size_t	size
	)

Perform an I2C read from an I2C master.

This function will perform an I2C read transfer.

Note: When using I2CSLAVE_MODE_BLOCKING, this must be called from a thread context.

The data written by the I2CSlave is synchronized with the START and STOP condition from an I2C master.

Parameters

[in]	handle	An I2CSlave_Handle returned from I2CSlave_open()
[in,out]	buffer	A pointer to buffer to store data read
[in]	size	The number of bytes to read into `buffer`

Return values

true	on successful read
false	on an error

See also: I2CSlave_read; I2CSlave_TransferMode

§ I2CSlave_write()

bool I2CSlave_write	(	I2CSlave_Handle	handle,
		const void *	buffer,
		size_t	size
	)

Perform an I2C write to an I2C master.

This function will perform an I2C write transfer.

Note: When using I2CSLAVE_MODE_BLOCKING, this must be called from a thread context.

The data written by the I2CSlave is synchronized with the START and STOP conditions from an I2C master.

Parameters

[in]	handle	An I2CSlave_Handle
[in]	buffer	A pointer to buffer containing data to write
[in]	size	The number of bytes in `buffer` to write. If the I2C master requests more than `size` bytes, this driver will transmit `0xFF` until a STOP condition is recieved.

Return values

true	on successful write
false	on an error

See also: I2CSlave_write; I2CSlave_TransferMode

Detailed Description

Overview

Usage

Synopsis

Examples

Opening the driver

Transferring data

Configuration

Data Structures

Macros

Typedefs

Enumerations

Functions

Typedef Documentation

§ I2CSlave_Handle

§ I2CSlave_CallbackFxn

§ I2CSlave_Config

Enumeration Type Documentation

§ I2CSlave_TransferMode

Function Documentation

§ I2CSlave_close()

§ I2CSlave_control()

§ I2CSlave_init()

§ I2CSlave_open()

§ I2CSlave_Params_init()

§ I2CSlave_read()

§ I2CSlave_write()