Inter-Driver API
[Driver Development API]

Collaboration diagram for Inter-Driver API:

Functions
struct rtdm_dev_context *	rtdm_context_get (int fd)
	Resolve file descriptor to device context.
int	rtdm_select_bind (int fd, rtdm_selector_t *selector, enum rtdm_selecttype type, unsigned fd_index)
	Bind a selector to specified event types of a given file descriptor.
void	rtdm_context_lock (struct rtdm_dev_context *context)
	Increment context reference counter.
void	rtdm_context_unlock (struct rtdm_dev_context *context)
	Decrement context reference counter.
int	rtdm_open (const char *path, int oflag,...)
	Open a device.
int	rtdm_socket (int protocol_family, int socket_type, int protocol)
	Create a socket.
int	rtdm_close (int fd)
	Close a device or socket.
int	rtdm_ioctl (int fd, int request,...)
	Issue an IOCTL.
ssize_t	rtdm_read (int fd, void *buf, size_t nbyte)
	Read from device.
ssize_t	rtdm_write (int fd, const void *buf, size_t nbyte)
	Write to device.
ssize_t	rtdm_recvmsg (int fd, struct msghdr *msg, int flags)
	Receive message from socket.
ssize_t	rtdm_recvfrom (int fd, void *buf, size_t len, int flags, struct sockaddr *from, socklen_t *fromlen)
	Receive message from socket.
ssize_t	rtdm_recv (int fd, void *buf, size_t len, int flags)
	Receive message from socket.
ssize_t	rtdm_sendmsg (int fd, const struct msghdr *msg, int flags)
	Transmit message to socket.
ssize_t	rtdm_sendto (int fd, const void *buf, size_t len, int flags, const struct sockaddr *to, socklen_t tolen)
	Transmit message to socket.
ssize_t	rtdm_send (int fd, const void *buf, size_t len, int flags)
	Transmit message to socket.
int	rtdm_bind (int fd, const struct sockaddr *my_addr, socklen_t addrlen)
	Bind to local address.
int	rtdm_connect (int fd, const struct sockaddr *serv_addr, socklen_t addrlen)
	Connect to remote address.
int	rtdm_listen (int fd, int backlog)
	Listen for incomming connection requests.
int	rtdm_accept (int fd, struct sockaddr *addr, socklen_t *addrlen)
	Accept a connection requests.
int	rtdm_shutdown (int fd, int how)
	Shut down parts of a connection.
int	rtdm_getsockopt (int fd, int level, int optname, void *optval, socklen_t *optlen)
	Get socket option.
int	rtdm_setsockopt (int fd, int level, int optname, const void *optval, socklen_t optlen)
	Set socket option.
int	rtdm_getsockname (int fd, struct sockaddr *name, socklen_t *namelen)
	Get local socket address.
int	rtdm_getpeername (int fd, struct sockaddr *name, socklen_t *namelen)
	Get socket destination address.

---

Function Documentation

int rtdm_accept	(	int	fd,
		struct sockaddr *	addr,
		socklen_t *	addrlen
	)

Accept a connection requests.

Refer to rt_dev_accept() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

int rtdm_bind	(	int	fd,
		const struct sockaddr *	my_addr,
		socklen_t	addrlen
	)

Bind to local address.

Refer to rt_dev_bind() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

int rtdm_close

(

int

fd

)

Close a device or socket.

Refer to rt_dev_close() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

int rtdm_connect	(	int	fd,
		const struct sockaddr *	serv_addr,
		socklen_t	addrlen
	)

Connect to remote address.

Refer to rt_dev_connect() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

struct rtdm_dev_context* rtdm_context_get

(

int

fd

)

[read]

Resolve file descriptor to device context.

Parameters:

[in]

fd

File descriptor

Returns:

Pointer to associated device context, or NULL on error

Note:

The device context has to be unlocked using rtdm_context_unlock() when it is no longer referenced.

Environments:

This service can be called from:

• Kernel module initialization/cleanup code
• Interrupt service routine
• Kernel-based task
• User-space task (RT, non-RT)

Rescheduling: never.

References rtdm_dev_context::context_flags, RTDM_CLOSING, and rtdm_context_lock().

Referenced by rtdm_select_bind().

void rtdm_context_lock

(

struct rtdm_dev_context *

context

)

Increment context reference counter.

Parameters:

[in]

context

Device context

Note:

rtdm_context_get() automatically increments the lock counter. You only need to call this function in special scenrios.

Environments:

This service can be called from:

• Kernel module initialization/cleanup code
• Interrupt service routine
• Kernel-based task
• User-space task (RT, non-RT)

Rescheduling: never.

Referenced by rtdm_context_get().

void rtdm_context_unlock

(

struct rtdm_dev_context *

context

)

Decrement context reference counter.

Parameters:

[in]

context

Device context

Note:

Every successful call to rtdm_context_get() must be matched by a rtdm_context_unlock() invocation.

Environments:

This service can be called from:

• Kernel module initialization/cleanup code
• Interrupt service routine
• Kernel-based task
• User-space task (RT, non-RT)

Rescheduling: never.

Referenced by rtdm_select_bind().

int rtdm_getpeername	(	int	fd,
		struct sockaddr *	name,
		socklen_t *	namelen
	)

Get socket destination address.

Refer to rt_dev_getpeername() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

int rtdm_getsockname	(	int	fd,
		struct sockaddr *	name,
		socklen_t *	namelen
	)

Get local socket address.

Refer to rt_dev_getsockname() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

int rtdm_getsockopt	(	int	fd,
		int	level,
		int	optname,
		void *	optval,
		socklen_t *	optlen
	)

Get socket option.

Refer to rt_dev_getsockopt() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

int rtdm_ioctl	(	int	fd,
		int	request,
			...
	)

Issue an IOCTL.

Refer to rt_dev_ioctl() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

int rtdm_listen	(	int	fd,
		int	backlog
	)

Listen for incomming connection requests.

Refer to rt_dev_listen() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

int rtdm_open	(	const char *	path,
		int	oflag,
			...
	)

Open a device.

Refer to rt_dev_open() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

ssize_t rtdm_read	(	int	fd,
		void *	buf,
		size_t	nbyte
	)

Read from device.

Refer to rt_dev_read() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

ssize_t rtdm_recv	(	int	fd,
		void *	buf,
		size_t	len,
		int	flags
	)

Receive message from socket.

Refer to rt_dev_recv() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

ssize_t rtdm_recvfrom	(	int	fd,
		void *	buf,
		size_t	len,
		int	flags,
		struct sockaddr *	from,
		socklen_t *	fromlen
	)

Receive message from socket.

Refer to rt_dev_recvfrom() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

ssize_t rtdm_recvmsg	(	int	fd,
		struct msghdr *	msg,
		int	flags
	)

Receive message from socket.

Refer to rt_dev_recvmsg() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

int rtdm_select_bind	(	int	fd,
		rtdm_selector_t *	selector,
		enum rtdm_selecttype	type,
		unsigned	fd_index
	)

Bind a selector to specified event types of a given file descriptor.

For internal use only.

This function is invoked by higher RTOS layers implementing select-like services. It shall not be called directly by RTDM drivers.

Parameters:

[in]	fd	File descriptor to bind to
[in,out]	selector	Selector object that shall be bound to the given event
[in]	type	Event type the caller is interested in
[in]	fd_index	Index in the file descriptor set of the caller

Returns:

0 on success, otherwise:

• -EBADF is returned if the file descriptor fd cannot be resolved.

• -EINVAL is returned if type or fd_index are invalid.

Environments:

This service can be called from:

• Kernel module initialization/cleanup code
• Kernel-based task
• User-space task (RT, non-RT)

Rescheduling: never.

References rtdm_dev_context::ops, rtdm_context_get(), rtdm_context_unlock(), and rtdm_operations::select_bind.

ssize_t rtdm_send	(	int	fd,
		const void *	buf,
		size_t	len,
		int	flags
	)

Transmit message to socket.

Refer to rt_dev_send() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

ssize_t rtdm_sendmsg	(	int	fd,
		const struct msghdr *	msg,
		int	flags
	)

Transmit message to socket.

Refer to rt_dev_sendmsg() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

ssize_t rtdm_sendto	(	int	fd,
		const void *	buf,
		size_t	len,
		int	flags,
		const struct sockaddr *	to,
		socklen_t	tolen
	)

Transmit message to socket.

Refer to rt_dev_sendto() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

int rtdm_setsockopt	(	int	fd,
		int	level,
		int	optname,
		const void *	optval,
		socklen_t	optlen
	)

Set socket option.

Refer to rt_dev_setsockopt() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

int rtdm_shutdown	(	int	fd,
		int	how
	)

Shut down parts of a connection.

Refer to rt_dev_shutdown() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

int rtdm_socket	(	int	protocol_family,
		int	socket_type,
		int	protocol
	)

Create a socket.

Refer to rt_dev_socket() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.

ssize_t rtdm_write	(	int	fd,
		const void *	buf,
		size_t	nbyte
	)

Write to device.

Refer to rt_dev_write() for parameters and return values

Environments:

Depends on driver implementation, see Device Profiles.

Rescheduling: possible.