M2MB I2C

This section describes the M2MB APIs to perform various I2C operations. More...

#define	I2C_FLAG_START   0x00000001
#define	I2C_FLAG_STOP   0x00000002
#define	I2C_FLAG_WRITE   0x00000004
#define	I2C_FLAG_READ   0x00000008
enum	M2MB_I2C_IOCTL_REQUEST {   M2MB_I2C_IOCTL_SET_CFG,   M2MB_I2C_IOCTL_GET_CFG }
typedef enum M2MB_I2C_IOCTL_REQUEST	M2MB_I2C_IOCTL_REQUEST_T
typedef void *	M2MB_I2C_ID_T
INT32	m2mb_i2c_open (const CHAR *path, INT32 flags,...)
	Open an I2C device. More...
INT32	m2mb_i2c_close (INT32 fd)
	Closes an I2C device. More...
INT32	m2mb_i2c_ioctl (INT32 fd, M2MB_I2C_IOCTL_REQUEST_T request,...)
	Configure the I2C device. More...
SSIZE_T	m2mb_i2c_read (INT32 fd, void *buf, SIZE_T nbyte)
	Read the I2C device. More...
SSIZE_T	m2mb_i2c_write (INT32 fd, const void *buf, SIZE_T nbyte)
	Write to I2C device. More...

Detailed Description

This section describes the M2MB APIs to perform various I2C operations.

Macro Definition Documentation

I2C_FLAG_READ

#define I2C_FLAG_READ   0x00000008

Must be set to indicate a READ transfer.

Definition at line 58 of file m2mb_i2c.h.

I2C_FLAG_START

#define I2C_FLAG_START   0x00000001

Specifies that the transfer begins with a START bit - S.

Definition at line 55 of file m2mb_i2c.h.

I2C_FLAG_STOP

#define I2C_FLAG_STOP   0x00000002

Specifies that the transfer ends with a STOP bit - P.

Definition at line 56 of file m2mb_i2c.h.

I2C_FLAG_WRITE

#define I2C_FLAG_WRITE   0x00000004

Must be set to indicate a WRITE transfer.

Definition at line 57 of file m2mb_i2c.h.

Typedef Documentation

M2MB_I2C_ID_T

typedef void* M2MB_I2C_ID_T

Definition at line 71 of file m2mb_i2c.h.

M2MB_I2C_IOCTL_REQUEST_T

typedef enum M2MB_I2C_IOCTL_REQUEST M2MB_I2C_IOCTL_REQUEST_T

Enumeration Type Documentation

M2MB_I2C_IOCTL_REQUEST

enum M2MB_I2C_IOCTL_REQUEST

Enumerator
M2MB_I2C_IOCTL_SET_CFG	set i2c device configuration
M2MB_I2C_IOCTL_GET_CFG	get i2c device configuration

Definition at line 63 of file m2mb_i2c.h.

Function Documentation

m2mb_i2c_close()

INT32 m2mb_i2c_close

(

INT32

fd

)

Closes an I2C device.

This API closes the requested I2C device

Parameters

[in]

fd

File Descriptor of I2C device

Returns

0 on SUCCESS

-1 on FAILURE

Note

This API frees the allocated memory to the configuration of type M2MB_I2C_CFG_T and releases the I2C device. On successful closing of the I2C port, allocated memory to the configuration is freed. In case of an error, memory allocation to configuration is not freed. Allowed From De-initialization and tasks Preemption Possible No

Example

INT32 fd;
    INT32 status;
    
    status = m2mb_i2c_close( fd );
    if(status == -1)
      app_dbg_printf("ERROR CLOSING I2C port\r\n");

m2mb_i2c_ioctl()

INT32 m2mb_i2c_ioctl	(	INT32	fd,
		M2MB_I2C_IOCTL_REQUEST_T	request,
			...
	)

Configure the I2C device.

This API set/get the I2C device configuration

Parameters

[in]	fd	File Descriptor of I2C device
[in]	request	required operation set/get configuration(see M2MB_I2C_IOCTL_REQUEST)

Returns

0 on SUCCESS

-1 on FAILURE

Note

This API allows to read/write the I2C configuration of type M2MB_I2C_CFG_T. On successful configuration, the requested operation (set/get configuration) is done. In case of an error, the requested operation (set/get configuration) could not be completed. Allowed From Events and tasks Preemption Possible No

Example

INT32 fd;
    INT32 status;
    M2MB_I2C_CFG_T *P_CFG, *P_ReadCFG;
    
    fd = m2mb_i2c_open("/dev/i2c-1", 0);
    if(fd == -1)
      app_dbg_printf("ERROR OPENING I2C port\r\n");

    P_CFG->bus_Frequency_KHz = I2C_SLAVE_FREQ;
    P_CFG->slave_Address = I2C_SLAVE_ADDR;
    P_CFG->SMBUS_Mode = 0;
    P_CFG->slave_Max_Clock_Stretch_Us = 0;
    P_CFG->core_Configuration1 = 0;
    P_CFG->core_Configuration2 = 0;
    P_CFG->flags = (I2C_FLAG_START | I2C_FLAG_STOP);
    
    status = m2mb_i2c_ioctl( fd, M2MB_I2C_IOCTL_SET_CFG, P_CFG );
    if(status == -1)
      app_dbg_printf("ERROR IN SET I2C\r\n");

    status = m2mb_i2c_ioctl( fd, M2MB_I2C_IOCTL_GET_CFG, P_ReadCFG );
    if(status == -1)
      app_dbg_printf("ERROR IN GET I2C\r\n");

m2mb_i2c_open()

INT32 m2mb_i2c_open	(	const CHAR *	path,
		INT32	flags,
			...
	)

Open an I2C device.

This API opens the requested I2C device

Parameters

[in]	path	Pointer to an I2C device to open
[in]	flags	currently unused

Returns

File Descriptor on SUCCESS

-1 on FAILURE

Note

This API allocates memory to the configuration of type M2MB_I2C_CFG_T. After successful opening of the I2C port, the File Descriptor points to M2MB_I2C_CFG_T. In case of an error in memory allocation or opening of the I2C port, it returns -1 Allowed From Initialization and tasks Preemption Possible No

Example

INT32 fd;
    
    fd = m2mb_i2c_open("/dev/i2c-1", 0);
    if(fd == -1)
      app_dbg_printf("ERROR OPENING I2C port\r\n");

m2mb_i2c_read()

SSIZE_T m2mb_i2c_read	(	INT32	fd,
		void *	buf,
		SIZE_T	nbyte
	)

Read the I2C device.

This API reads the data bytes from the I2C device

Parameters

[in]	fd	File Descriptor of I2C device
[in,out]	buf	reference to the data to be read
[in]	nbyte	number of data bytes to be read

Returns

number of data bytes read on SUCCESS

-1 on FAILURE

Note

This API reads the data bytes from the I2C device. On success, the read data bytes are updated in the reference provided. In case of an error, data bytes are not read from the I2C device. Allowed From Events and tasks Preemption Possible No

Example

INT32 fd;
fd = m2mb_i2c_open("/dev/i2c-1", 0);
if(fd == -1)
    app_dbg_printf("ERROR OPENING I2C port\r\n");
    bytecnt = m2mb_i2c_read( fd, (void* )P_ReadByte, 1);

m2mb_i2c_write()

SSIZE_T m2mb_i2c_write	(	INT32	fd,
		const void *	buf,
		SIZE_T	nbyte
	)

Write to I2C device.

This API writes the data bytes to the I2C device

Parameters

[in]	fd	File Descriptor of the I2C device
[in]	buf	reference to the data to be written
[in]	nbyte	number of data bytes to be write

Returns

number of data bytes written on SUCCESS

-1 on FAILURE

Note

This API writes the data bytes to the I2C device. On success, the data bytes are successfully written to the I2C device. In case of an error, write data bytes to the I2C device has failed. Every API allowed from events and tasks preemption possible No

Example

bytecnt = m2mb_i2c_write( fd, (void* )P_WriteByte, size);