I2C Class Reference

Private data for an I2C device. More...

#include <I2C.hxx>

Inheritance diagram for I2C:

Protected Member Functions
	I2C (const char *name)
	Constructor.
	~I2C ()
	Destructor.
virtual int	transfer (struct i2c_msg *msg, bool stop)=0
	Method to transmit/receive the data.
Protected Member Functions inherited from Node
	Node (const char *name)
	Constructor.
virtual	~Node ()
	Destructor.
virtual void	enable ()=0
	This will be called once when reference-count goes from 0 to positive.
virtual void	disable ()=0
	This will be called when reference count goes from non-zero to 0.
int	open (File *, const char *, int, int) OVERRIDE
	Open method.
int	close (File *) OVERRIDE
	Close method.
virtual int	fstat (File *file, struct stat *stat) override
	Get the status information of a file or device.
Protected Member Functions inherited from FileIO
	FileIO (const char *name)
	Constructor.
virtual	~FileIO ()
	Destructor.
virtual off_t	lseek (File *f, off_t offset, int whence)
	Seek method.
virtual int	fcntl (File *file, int cmd, unsigned long data)
	Manipulate a file descriptor.
virtual bool	select (File *file, int mode)
	Device select method.

Private Member Functions
ssize_t	read (File *file, void *buf, size_t count) OVERRIDE
	Read from a file or device.
ssize_t	write (File *file, const void *buf, size_t count) OVERRIDE
	Write to a file or device.
int	ioctl (File *file, unsigned long int key, unsigned long data) OVERRIDE
	Request an ioctl transaction.
int	transfer_messages (struct i2c_msg *msgs, int num)
	Conduct multiple message transfers with one stop at the end.
int	smbus (File *file, unsigned long data)
	Request an smbus (ioctl) transaction.
void	flush_buffers () OVERRIDE
	Discards all pending buffers.
	I2C ()
	Default constructor.
	DISALLOW_COPY_AND_ASSIGN (I2C)

Additional Inherited Members
Public Member Functions inherited from Device
	Device (const char *name)
	Constructor.
virtual	~Device ()
	Destructor.
Static Public Member Functions inherited from Device
static int	open (struct _reent *reent, const char *path, int flags, int mode)
	Open a file or device.
static int	close (struct _reent *reent, int fd)
	Close a file or device.
static int	stat (struct _reent *reent, const char *path, struct stat *stat)
	Get the status information of a file or device.
static int	select (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, long long timeout)
	POSIX select().
static void	select_clear ()
	Clears the current thread's select bits.
Static Public Member Functions inherited from FileIO
static ssize_t	read (struct _reent *reent, int fd, void *buf, size_t count)
	Read from a file or device.
static ssize_t	write (struct _reent *reent, int fd, const void *buf, size_t count)
	Write to a file or device.
static _off_t	lseek (struct _reent *reent, int fd, _off_t offset, int whence)
	Change the offset index of a file or device.
static int	fstat (struct _reent *reent, int fd, struct stat *stat)
	Get the status information of a file or device.
static int	ioctl (int fd, unsigned long int key, unsigned long data)
	Request and ioctl transaction.
static int	fcntl (int fd, int cmd, unsigned long data)
	Manipulate a file descriptor.
static bool	is_device (int fd)
	Test if the file descriptor belongs to a device.
Static Protected Member Functions inherited from Device
static void	select_insert (SelectInfo *info)
	Add client to list of clients needing woken.
static void	select_wakeup (SelectInfo *info)
	Wakeup the list of clients needing woken.
static void	select_wakeup_from_isr (SelectInfo *info, int *woken)
	Wakeup the list of clients needing woken.
Static Protected Member Functions inherited from FileIO
static int	fd_alloc (void)
	Allocate a free file descriptor.
static void	fd_free (int fd)
	Free up a file descriptor.
static File *	file_lookup (int fd)
	Looks up a reference to a File corresponding to a given file descriptor.
static int	fd_lookup (File *file)
	Looks up a file descriptor corresponding to a given File reference.
Protected Attributes inherited from Node
OSMutex	lock_
	protects internal structures.
mode_t	mode_
	File open mode, such as O_NONBLOCK.
unsigned int	references_
	number of open references
Protected Attributes inherited from FileIO
const char *	name
	device name
Static Protected Attributes inherited from FileIO
static const unsigned int	numOpenFiles = 20
static File	files []
	File descriptor pool.
static OSMutex	mutex
	mutual exclusion for fileio

Detailed Description

Private data for an I2C device.

This device only supports blocking mode transfers.

Definition at line 50 of file I2C.hxx.

Constructor & Destructor Documentation

I2C()

I2C::I2C ( const char *  name )

inlineprotected

Constructor.

Parameters

name	device name in file system

Definition at line 56 of file I2C.hxx.

~I2C()

I2C::~I2C ( )

inlineprotected

Destructor.

Definition at line 63 of file I2C.hxx.

Member Function Documentation

flush_buffers()

void I2C::flush_buffers ( )

inlineprivatevirtual

Discards all pending buffers.

Called after disable().

Implements Node.

Definition at line 115 of file I2C.hxx.

ioctl()

int I2C::ioctl ( File *  file, unsigned long int  key, unsigned long  data  )

privatevirtual

Request an ioctl transaction.

Parameters

file	file reference for this device
key	ioctl key
data	key data

Returns

>= 0 upon success, -errno upon failure

Parameters

file	file reference for this device
key	ioctl key
data	key data

Returns

0 upon success, -errno upon failure

Reimplemented from FileIO.

Definition at line 101 of file I2C.cxx.

read()

ssize_t I2C::read ( File *  file, void *  buf, size_t  count  )

privatevirtual

Read from a file or device.

Parameters

file	file reference for this device
buf	location to place read data
count	number of bytes to read

Returns

number of bytes read upon success, -errno upon failure

Implements FileIO.

Definition at line 45 of file I2C.cxx.

smbus()

int I2C::smbus ( File *  file, unsigned long  data  )

private

Request an smbus (ioctl) transaction.

Parameters

file	file reference for this device
data	smbus data

Returns

0 upon success, -errno upon failure

Todo:

need to finish implementation (Stuart Baker)

Definition at line 156 of file I2C.cxx.

transfer()

virtual int I2C::transfer ( struct i2c_msg *  msg, bool  stop  )

protectedpure virtual

Method to transmit/receive the data.

Parameters

msg	message to transact.
stop	produce a stop condition at the end of the transfer

Returns

bytes transfered upon success or -1 with errno set

Implemented in BitBangI2C< HW >, Stm32I2C, and TivaI2C.

transfer_messages()

int I2C::transfer_messages ( struct i2c_msg *  msgs, int  num  )

private

Conduct multiple message transfers with one stop at the end.

Parameters

msgs	array of messages to transfer
num	number of messages to transfer

Returns

total number of bytes transfered, -errno upon failure

Definition at line 128 of file I2C.cxx.

write()

ssize_t I2C::write ( File *  file, const void *  buf, size_t  count  )

privatevirtual

Write to a file or device.

Parameters

file	file reference for this device
buf	location to find write data
count	number of bytes to write

Returns

number of bytes written upon success, -errno upon failure

Implements FileIO.

Definition at line 73 of file I2C.cxx.

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The documentation for this class was generated from the following files:

• I2C.hxx
• I2C.cxx