Serial Devices
[Device Profiles]

Collaboration diagram for Serial Devices:

---

Detailed Description

This is the common interface a RTDM-compliant serial device has to provide. Feel free to comment on this profile via the Xenomai mailing list (Xenomai-core@gna.org) or directly to the author (jan.kiszka@web.de).

Profile Revision: 2

Device Characteristics

Device Flags: RTDM_NAMED_DEVICE, RTDM_EXCLUSIVE

Device Name: "rtser<N>", N >= 0

Device Class: RTDM_CLASS_SERIAL

Supported Operations

Open
Environments: non-RT (RT optional)
Specific return values: none

Close
Environments: non-RT (RT optional)
Specific return values: none

IOCTL
Mandatory Environments: see below
Specific return values: see below

Read
Environments: RT (non-RT optional)
Specific return values:

• -ETIMEDOUT
• -EINTR (interrupted explicitly or by signal)
• -EAGAIN (no data available in non-blocking mode)
• -EBADF (device has been closed while reading)
• -EIO (hardware error or broken bit stream)

Write
Environments: RT (non-RT optional)
Specific return values:

• -ETIMEDOUT
• -EINTR (interrupted explicitly or by signal)
• -EAGAIN (no data written in non-blocking mode)
• -EBADF (device has been closed while writing)

Files
file	rtserial.h
	Real-Time Driver Model for Xenomai, serial device profile header.
Data Structures
struct	rtser_config_t
	Serial device configuration. More...
struct	rtser_status_t
	Serial device status. More...
struct	rtser_event_t
	Additional information about serial device events. More...
RTSER_DEF_BAUD
Default baud rate
#define	RTSER_DEF_BAUD   9600
RTSER_xxx_PARITY
Number of parity bits
#define	RTSER_NO_PARITY   0x00
#define	RTSER_ODD_PARITY   0x01
#define	RTSER_EVEN_PARITY   0x03
#define	RTSER_DEF_PARITY   RTSER_NO_PARITY
RTSER_xxx_BITS
Number of data bits
#define	RTSER_5_BITS   0x00
#define	RTSER_6_BITS   0x01
#define	RTSER_7_BITS   0x02
#define	RTSER_8_BITS   0x03
#define	RTSER_DEF_BITS   RTSER_8_BITS
RTSER_xxx_STOPB
Number of stop bits
#define	RTSER_1_STOPB   0x00
#define	RTSER_1_5_STOPB   0x01
	valid only in combination with 5 data bits
#define	RTSER_2_STOPB   0x01
#define	RTSER_DEF_STOPB   RTSER_1_STOPB
RTSER_xxx_HAND
Handshake mechanisms
#define	RTSER_NO_HAND   0x00
#define	RTSER_RTSCTS_HAND   0x01
#define	RTSER_DEF_HAND   RTSER_NO_HAND
RTSER_FIFO_xxx
Reception FIFO interrupt threshold
#define	RTSER_FIFO_DEPTH_1   0x00
#define	RTSER_FIFO_DEPTH_4   0x40
#define	RTSER_FIFO_DEPTH_8   0x80
#define	RTSER_FIFO_DEPTH_14   0xC0
#define	RTSER_DEF_FIFO_DEPTH   RTSER_FIFO_DEPTH_1
RTSER_TIMEOUT_xxx
Special timeout values, see also RTDM_TIMEOUT_xxx
#define	RTSER_TIMEOUT_INFINITE   RTDM_TIMEOUT_INFINITE
#define	RTSER_TIMEOUT_NONE   RTDM_TIMEOUT_NONE
#define	RTSER_DEF_TIMEOUT   RTDM_TIMEOUT_INFINITE
RTSER_xxx_TIMESTAMP_HISTORY
Timestamp history control
#define	RTSER_RX_TIMESTAMP_HISTORY   0x01
#define	RTSER_DEF_TIMESTAMP_HISTORY   0x00
RTSER_EVENT_xxx
Events bits
#define	RTSER_EVENT_RXPEND   0x01
#define	RTSER_EVENT_ERRPEND   0x02
#define	RTSER_EVENT_MODEMHI   0x04
#define	RTSER_EVENT_MODEMLO   0x08
#define	RTSER_DEF_EVENT_MASK   0x00
RTSER_SET_xxx
Configuration mask bits
#define	RTSER_SET_BAUD   0x0001
#define	RTSER_SET_PARITY   0x0002
#define	RTSER_SET_DATA_BITS   0x0004
#define	RTSER_SET_STOP_BITS   0x0008
#define	RTSER_SET_HANDSHAKE   0x0010
#define	RTSER_SET_FIFO_DEPTH   0x0020
#define	RTSER_SET_TIMEOUT_RX   0x0100
#define	RTSER_SET_TIMEOUT_TX   0x0200
#define	RTSER_SET_TIMEOUT_EVENT   0x0400
#define	RTSER_SET_TIMESTAMP_HISTORY   0x0800
#define	RTSER_SET_EVENT_MASK   0x1000
RTSER_LSR_xxx
Line status bits
#define	RTSER_LSR_DATA   0x01
#define	RTSER_LSR_OVERRUN_ERR   0x02
#define	RTSER_LSR_PARITY_ERR   0x04
#define	RTSER_LSR_FRAMING_ERR   0x08
#define	RTSER_LSR_BREAK_IND   0x10
#define	RTSER_LSR_THR_EMTPY   0x20
#define	RTSER_LSR_TRANSM_EMPTY   0x40
#define	RTSER_LSR_FIFO_ERR   0x80
#define	RTSER_SOFT_OVERRUN_ERR   0x0100
RTSER_MSR_xxx
Modem status bits
#define	RTSER_MSR_DCTS   0x01
#define	RTSER_MSR_DDSR   0x02
#define	RTSER_MSR_TERI   0x04
#define	RTSER_MSR_DDCD   0x08
#define	RTSER_MSR_CTS   0x10
#define	RTSER_MSR_DSR   0x20
#define	RTSER_MSR_RI   0x40
#define	RTSER_MSR_DCD   0x80
RTSER_MCR_xxx
Modem control bits
#define	RTSER_MCR_DTR   0x01
#define	RTSER_MCR_RTS   0x02
#define	RTSER_MCR_OUT1   0x04
#define	RTSER_MCR_OUT2   0x08
#define	RTSER_MCR_LOOP   0x10
RTSER_BREAK_xxx
Break control
#define	RTSER_BREAK_CLR   0x00
#define	RTSER_BREAK_SET   0x01
#define	RTIOC_TYPE_SERIAL   RTDM_CLASS_SERIAL
Sub-Classes of RTDM_CLASS_SERIAL
#define	RTDM_SUBCLASS_16550A   0
IOCTLs
Serial device IOCTLs
#define	RTSER_RTIOC_GET_CONFIG   _IOR(RTIOC_TYPE_SERIAL, 0x00, struct rtser_config)
	Get serial device configuration.
#define	RTSER_RTIOC_SET_CONFIG   _IOW(RTIOC_TYPE_SERIAL, 0x01, struct rtser_config)
	Set serial device configuration.
#define	RTSER_RTIOC_GET_STATUS   _IOR(RTIOC_TYPE_SERIAL, 0x02, struct rtser_status)
	Get serial device status.
#define	RTSER_RTIOC_GET_CONTROL   _IOR(RTIOC_TYPE_SERIAL, 0x03, int)
	Get serial device's modem contol register.
#define	RTSER_RTIOC_SET_CONTROL   _IOW(RTIOC_TYPE_SERIAL, 0x04, int)
	Set serial device's modem contol register.
#define	RTSER_RTIOC_WAIT_EVENT   _IOR(RTIOC_TYPE_SERIAL, 0x05, struct rtser_event)
	Wait on serial device events according to previously set mask.
Defines
#define	RTSER_RTIOC_BREAK_CTL   _IOR(RTIOC_TYPE_SERIAL, 0x06, int)
	Set or clear break on UART output line.

---

Define Documentation

#define RTSER_RTIOC_BREAK_CTL   _IOR(RTIOC_TYPE_SERIAL, 0x06, int)

Set or clear break on UART output line.

Parameters:

[in]

arg

RTSER_BREAK_SET or RTSER_BREAK_CLR (int)

Returns:

0 on success, otherwise negative error code

Environments:

This service can be called from:

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

Note:

A set break condition may also be cleared on UART line reconfiguration.

Rescheduling: never.

#define RTSER_RTIOC_GET_CONFIG   _IOR(RTIOC_TYPE_SERIAL, 0x00, struct rtser_config)

Get serial device configuration.

Parameters:

[out]

arg

Pointer to configuration buffer (struct rtser_config)

Returns:

0 on success, otherwise negative error code

Environments:

This service can be called from:

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

Rescheduling: never.

#define RTSER_RTIOC_GET_CONTROL   _IOR(RTIOC_TYPE_SERIAL, 0x03, int)

Get serial device's modem contol register.

Parameters:

[out]

arg

Pointer to variable receiving the content (int, see RTSER_MCR_xxx)

Returns:

0 on success, otherwise negative error code

Environments:

This service can be called from:

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

Rescheduling: never.

#define RTSER_RTIOC_GET_STATUS   _IOR(RTIOC_TYPE_SERIAL, 0x02, struct rtser_status)

Get serial device status.

Parameters:

[out]

arg

Pointer to status buffer (struct rtser_status)

Returns:

0 on success, otherwise negative error code

Environments:

This service can be called from:

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

Note:

The error states RTSER_LSR_OVERRUN_ERR, RTSER_LSR_PARITY_ERR, RTSER_LSR_FRAMING_ERR, and RTSER_SOFT_OVERRUN_ERR that may have occured during previous read accesses to the device will be saved for being reported via this IOCTL. Upon return from RTSER_RTIOC_GET_STATUS, the saved state will be cleared.

Rescheduling: never.

#define RTSER_RTIOC_SET_CONFIG   _IOW(RTIOC_TYPE_SERIAL, 0x01, struct rtser_config)

Set serial device configuration.

Parameters:

[in]

arg

Pointer to configuration buffer (struct rtser_config)

Returns:

0 on success, otherwise:

• -EPERM is returned if the caller's context is invalid, see note below.

• -ENOMEM is returned if a new history buffer for timestamps cannot be allocated.

Environments:

This service can be called from:

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

Note:

If rtser_config contains a valid timestamp_history and the addressed device has been opened in non-real-time context, this IOCTL must be issued in non-real-time context as well. Otherwise, this command will fail.

Rescheduling: never.

Examples:

cross-link.c.

#define RTSER_RTIOC_SET_CONTROL   _IOW(RTIOC_TYPE_SERIAL, 0x04, int)

Set serial device's modem contol register.

Parameters:

[in]

arg

New control register content (int, see RTSER_MCR_xxx)

Returns:

0 on success, otherwise negative error code

Environments:

This service can be called from:

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

Rescheduling: never.

#define RTSER_RTIOC_WAIT_EVENT   _IOR(RTIOC_TYPE_SERIAL, 0x05, struct rtser_event)

Wait on serial device events according to previously set mask.

Parameters:

[out]

arg

Pointer to event information buffer (struct rtser_event)

Returns:

0 on success, otherwise:

• -EBUSY is returned if another task is already waiting on events of this device.

• -EBADF is returned if the file descriptor is invalid or the device has just been closed.

Environments:

This service can be called from:

• Kernel-based task
• User-space task (RT)

Rescheduling: possible.

Examples:

cross-link.c.

---