i2c.h

umon bootloader source code, support mips cpu.

/* i2c.h:
 * Header for I-Squared-C code.
 */

extern int i2cVerbose;

/********************************************************************
 *
 * Commands used by i2cCtrl():
 */
#define I2CCTRL_INIT	1
#define I2CCTRL_SHOW	2
#define	I2CCTRL_START	3		/* Send START condition */
#define	I2CCTRL_STOP	4		/* Send STOP condition */
#define	I2CCTRL_WADD	5		/* Send Write address */
#define	I2CCTRL_RADD	6		/* Send Read address */
#define	I2CCTRL_RDAT	7		/* Read data */
#define	I2CCTRL_WDAT	8		/* Write data */
#define	I2CCTRL_SACK	9		/* Send ACK */
#define	I2CCTRL_WACK	10		/* WaitFor ACK */

/********************************************************************
 *
 * Upper bits of the bigaddr integer used for special case read/write
 */
#define REPEATED_START	0x40000000
#define OMIT_STOP		0x20000000

/********************************************************************
 *
 * Functions that must be provided from some target-specific code.
 */


/* i2cCtrl()
 * Parameters:
 *	int interface-
 *		This parameter supports the case where the target hardware has more
 *		than one i2c controller.  The interface number would correspond to
 *		one of potentially several different controllers.
 *	int cmd-
 *		Command to be carried out by the control function.
 *	ulong arg1-
 *		First command-specific argument.
 *	ulong arg2-
 *		Second command-specific argument.
 */
extern int i2cCtrl(int interface,int cmd,unsigned long arg1,unsigned long arg2);

/* i2cRead()
 * Parameters:
 *	int interface-
 *		See description under i2cCtrl.
 *	int bigaddr-
 *		The device address on the I2C bus.  Referred to here as "big" because
 *		it is an "int" so it supports 10-bit addresses (if needed).
 *	uchar *data-
 *		Pointer to the data buffer into which the data is to be placed.
 *	int len-
 *		Number of bytes to be read from the I2C device.  This must not be
 *		larger than the size of the data buffer.
 * Return:
 *	int
 *		The function should return the number of bytes read.  If everything
 *		went well, then the return value should equal the len parameter.
 *		Negative represents some failure.
 */
extern int i2cRead(int interface,int bigaddr,unsigned char *data,int len);

/* i2cWrite()
 * Parameters:
 *	int interface-
 *		See description under i2cCtrl.
 *	int bigaddr-
 *		See description under i2cRead.
 *	uchar *data-
 *		Buffer from which the data is to be taken and put into the specified
 *		I2C device.
 *	int len-
 *		Number of bytes to be written.
 * Return:
 *	int
 *		The function should return the number of bytes written.  If everything
 *		went well, then the return value should equal the len parameter.
 *		Negative represents some failure.
 */
extern int i2cWrite(int interface,int bigaddr,unsigned char *data,int len);

/* i2cShow()
 * Parameters:
 *	int interface-
 *		See description under i2cCtrl.
 * Return:
 *	void
 *		The function should be part of target-specific code that simply
 *		prints out a list of the device names and their address on the 
 *		I-Squared-C bus of the specfied interface.
 */
extern void i2cShow(int interface);