i2c.h

来自「是一个手机功能的模拟程序」· C头文件 代码 · 共 235 行

//===========================================================================
//	I2C.H
//---------------------------------------------------------------------------
//	Copyright (c) 2002 Epson Research and Development, Inc.
//	All Rights Reserved.
//===========================================================================
// (Tabs set to every 4)


#ifndef __I2C_H__
#define __I2C_H__


#include "datatype.h"


#define I2C_ERR_NONE					0		// No error
#define I2C_ERR_STUCK_BIT				1		// SCL/SDA line stuck low too long
#define I2C_ERR_SLAVE_NACK_ID			2		// Slave NACK'd slave device ID (no such device)
#define I2C_ERR_SLAVE_NACK_DATA			3		// Slave NACK'd a sent data byte (error)
#define I2C_ERR_INVALID_ARGUMENT		4		// Call to i2cInitialize used incorrect arguments
#define I2C_ERR_UNKNOWN_ERROR			5		// Unknown error - MUST BE LAST!!!


#ifdef __cplusplus
   extern "C" {
#endif


//---------------------------------------------------------------------------
//  FUNCTION: i2cInitialize()
//
//  DESCRIPTION:
//		This routine initializes the I2C bus operating environment.
//		Repeated Start condition is set to TRUE.
//		Auto Increment mode is set to TRUE.
//		This function now calls the 2 subsequent functions: i2cInitializeLib()
//		and i2cInitializeHW() in order to have separate control and yet 
//		maintain backwards compatibility.
//
//  PARAMETERS:
//		SizeOf all chip register access (8,16,32).
//		Registers and bitmasks to access the I2C bus via GPIO pins.
//
//  RETURNS:
//		True if successful, False if I2C errors.
//---------------------------------------------------------------------------
Boolean i2cInitialize( int RegSize, UInt32 RegDir, UInt32 RegData, UInt32 SCLDir, UInt32 SCLData, UInt32 SDADir, UInt32 SDAData );

//---------------------------------------------------------------------------
//  FUNCTION: i2cInitializeLib()
//
//  DESCRIPTION:
//		This routine initializes the I2C library.
//		Repeated Start condition is set to TRUE.
//		Auto Increment mode is set to TRUE.
//
//  PARAMETERS:
//		SizeOf all chip register access (8,16,32).
//		Registers and bitmasks to access the I2C bus via GPIO pins.
//
//  RETURNS:
//		True if successful, False if I2C errors.
//---------------------------------------------------------------------------
Boolean i2cInitializeLib( void );

//---------------------------------------------------------------------------
//  FUNCTION: i2cInitializeHW()
//
//  DESCRIPTION:
//		This routine initializes the I2C hardware and assumes that the library
//		has already been initialized.
//
//  PARAMETERS:
//		n/a
//
//  RETURNS:
//		True if successful, False if I2C errors.
//---------------------------------------------------------------------------
Boolean i2cInitializeHW( void );

//---------------------------------------------------------------------------
//  FUNCTION: i2cSetSlaveDevice()
//
//  DESCRIPTION:
//		This function establishes the Save Device ID for I2C functions.
//
//  PARAMETERS:
//		Slave Device ID.
//
//  RETURNS:
//		Previous Slave Device ID, zero if nothing previously specified.
//---------------------------------------------------------------------------
UInt8 i2cSetSlaveDevice( UInt8 SlaveDevice );



//---------------------------------------------------------------------------
//  FUNCTION: i2cGetLastError()
//
//  DESCRIPTION:
//		Returns the last error code generated by any FALSE return result.
//
//  PARAMETERS:
//		n/a
//
//  RETURNS:
//		Last error code, zero if no previous error.
//---------------------------------------------------------------------------
int i2cGetLastError( void );



//---------------------------------------------------------------------------
//  FUNCTION: i2cGetLastErrorText()
//
//  DESCRIPTION:
//		Returns the last error text generated by any FALSE return result.
//
//  PARAMETERS:
//		n/a
//
//  RETURNS:
//		Last error text, or the text "No error" if no previous error.
//---------------------------------------------------------------------------
const char * i2cGetLastErrorText( void );



//---------------------------------------------------------------------------
//  FUNCTION: i2cSetAutoIncrement()
//
//  DESCRIPTION:
//		Enables or disables Auto Increment mode for sub-addressing writing.
//		This function modifies the behavior of function i2cWriteBytes().  When
//		the Auto Increment flag is set, the i2cWriteBytes() function writes
//		the data to the slave device as a contiguous sequence of bytes.  When
//		the Auto Increment flag is clear, the i2cWriteBytes() function reads
//		the first data byte (as the starting sub-address), and then it calls
//		i2cWrite2Bytes() for each subsequent data byte, auto-incrementing the
//		the sub-address for each data byte.  It is the caller's responsibility
//		to set this flag for each slave device, when using i2cWriteBytes().
//
//  PARAMETERS:
//		Flag TRUE or FALSE to enable/disable Auto Increment mode.
//
//  RETURNS:
//		State of the Auto Increment flag BEFORE being called (last state).
//---------------------------------------------------------------------------
Boolean i2cSetAutoIncrement( Boolean fAutoIncrement );



//---------------------------------------------------------------------------
//  FUNCTION: i2cSetRepeatedStart()
//
//  DESCRIPTION:
//		Enables or disables Repeated Start condition for sub-addressing reading.
//		This function modifies the behavior of function i2cReadBytes().  When
//		the Repeated Start flag is set, I2C data is read like this:
//			I2C_START, SLAVE_ADDRESS_WRITE, SUB_ADDRESS,
//			REPEATED_I2C_START, SLAVE_ADDRESS_READ, (read data...), I2C_STOP
//		When the Repeated Start flag is clear, I2C data is read like this:
//			I2C_START, SLAVE_ADDRESS_WRITE, SUB_ADDRESS, I2C_STOP
//			I2C_START, SLAVE_ADDRESS_READ, (read data...), I2C_STOP
//		It is the caller's responsibility to set this flag for each slave device.
//
//  PARAMETERS:
//		Flag TRUE or FALSE to enable/disable Repeated Start condition.
//
//  RETURNS:
//		State of the Repeated Start flag BEFORE being called (last state).
//---------------------------------------------------------------------------
Boolean i2cSetRepeatedStart( Boolean fRepeatedStart );



//---------------------------------------------------------------------------
//  FUNCTION: i2cWriteBytes()
//
//  DESCRIPTION:
//		This function writes BYTE data to the I2C bus.
//		If the Auto Increment flag is clear, this function assumes the first
//		byte of data is the starting sub-address.  If the Auto Increment flag
//		is set, this function makes no assumptions on the data stream.
//
//  PARAMETERS:
//		Number of bytes and pointer to byte data array.
//
//  RETURNS:
//		TRUE if successful, FALSE if error occurred.
//---------------------------------------------------------------------------
Boolean i2cWriteBytes( const UInt8 *pBytes, int nBytes );



//---------------------------------------------------------------------------
//  FUNCTION: i2cWrite2Bytes()
//
//  DESCRIPTION:
//		This function writes 2 BYTEs of data to the I2C bus.
//
//  PARAMETERS:
//		Data byte 1 (typically sub-address), data byte 2 (typically data).
//
//  RETURNS:
//		TRUE if successful, FALSE if error occurred.
//---------------------------------------------------------------------------
Boolean i2cWrite2Bytes( UInt8 Byte1, UInt8 Byte2 );


//---------------------------------------------------------------------------
//  FUNCTION: i2cReadBytes()
//
//  DESCRIPTION:
//		This function reads BYTE data from the I2C bus.
//
//  PARAMETERS:
//		Number of bytes and pointer to byte data array.
//		Optional (if non-NULL) starting subaddress.
//
//  RETURNS:
//		TRUE if successful, FALSE if error occurred.
//---------------------------------------------------------------------------
Boolean i2cReadBytes( const UInt8 *pSubAddress, UInt8 *pBytes, int nBytes );


#ifdef __cplusplus
   }
#endif



#endif //__I2C_H__