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TTYDEV

Structure for a tty device

Synopsis:

typedef struct ttydev_entry {
	iofunc_attr_t			attr;
	iofunc_mount_t			mount;
	TTYWAIT					*waiting_read;
	TTYWAIT					*waiting_write;
	TTYWAIT					*waiting_drain;
	int						c_cflag;
	int						c_iflag;
	int						c_lflag;
	int						c_oflag;
	volatile unsigned		flags;
	volatile unsigned       xflags;
    int						bcnt;
	int						fwdcnt;
	struct ttydev_entry		*timer;
	int			 			timeout;
	int			 			timeout_reset;
	union {
		int					tmrs;
		struct {
			char			spare_tmr;
			char			tx_tmr;
			char			brk_tmr;
			char			dtr_tmr;
		}	s;
	} 		un;
	pid_t					brkpgrp;
	pid_t			 		huppid;
    cc_t			 		c_cc[NCCS];
	unsigned char		 	fifo;
	unsigned char		 	fwd;
	unsigned char		 	prefix_cnt;
	unsigned char		 	oband_data;
	int			 			highwater;
	int			 			baud;
	struct winsize			winsize;
	TTYBUF	 				obuf;
	TTYBUF	 				ibuf;
	TTYBUF	 				cbuf;
	iofunc_notify_t		 	notify[3];
	struct ttydev_entry		*extra;
	TTYWAIT					*waiting_open;	
	void					*reserved2;		/* reserved for use by io-char */
	int						(*io_devctlext)(resmgr_context_t *ctp, io_devctl_t *msg, iofunc_ocb_t *ocb);
	char			 		name[TTY_NAME_MAX];
	} TTYDEV;

Description:

A character driver shares the TTYDEV structure with the io-char library.

This structure is used to handle devices shared between the driver and io-char.

The members include:

attr

A resource manager attribute

mount

Related to resource manager information

waiting_read

The queue to store blocking clients waiting to read

waiting_write

The queue to store blocking clients waiting to write

waiting_drain

The queue to store blocking clients waiting to drain.

c_cflag

POSIX termios flag describing the hardware control of the terminal

c_iflag

POSIX termios flag describing the basic terminal input control

c_lflag

POSIX termios flag used to control various terminal functions

c_oflag

POSIX termios flag describing the basic terminal output control

flags

The following flags are currently defined:

• OHW_PAGED -- the output hardware flow control (set by io-char and used by the driver)
• IHW_PAGED -- input hardware flow control is asserted; the device's highwater mark has been reached and doen't want to receive any more data. This flag also asserts the RTS line.
• OSW_PAGED -- output software flow control is asserted; the device should not transmit any data (set by io-char and used by the driver)
• ISW_PAGED -- input software flow control is asserted; the device's highwater mark has been reached and doesn't want to receive any more data. This flag also transmits VSTOP.
• EDIT_INSERT -- for edit mode. Insert or overstrike typing mode.
• EDIT_PREFIX -- for edit mode. Look for edit keys which begin with a fixed prefix, e.g. ESC [ ansi" used with POSIX c_cc[VPREFIX].
• OBAND_DATA -- indicates that out-of-band data is available
• LOSES_TX_INTR -- set if the hardware loses the tx interrupt. Causes a periodic timer to call tto() to transmit data.
• TIMER_ACTIVE -- used by io-char
• TIMER_KEEP -- used by io-char
• NOTTY -- used by PTYs
• NL_INSERT -- used to notify application if a \n was changed to a \r
• ISAPTY -- used by PTYs
• PTY_MASTER_ONLY -- used by PTYs
• LITERAL -- used by io-char
• FIRST_TIME_ALONE -- used by io-char

xflags

OSW_PAGED_OVERRIDE -- override OSW_PAGED to allow transmission of controlled characters when in a software flow control suspend state. This flag is set by io-char and is used and cleared by the driver.

bcnt

Internal to io-char and used to determine the number of bytes needed to notify a read client.

fwdcnt

Internal to io-char and used to determine the number of fwd counts.

timer

Used by io-char.

timeout

Used by io-char.

timeout_reset

Used by io-char.

tmrs

One of several available for io-char to use.

spare_tmr

Spare used only by io-char for drain.

tx_tmr

Enabled by LOSES_TX_INTR. The timer causes tto() to be called to work around some parts that lose transmit interrupts.

brk_tmr

Used only by io-char sending break; calls tto() (TTO_CTRL, dtrchg).

dtr_tmr

Used by io-char to set dtr line i.e. generate SIGHUP calls tto() (TTO_CTRL, dtrchg).

brkpgrp

Used by io-char.

huppid

Used by io-char.

c_cc

POSIX special control-characters.

fifo

Used only by the driver.

fwd

Forward character used by io-char. It's used with fwdcnt to implement forward, described in readcond().

prefix_cnt

For io-char only.

oband_data

Out-of-band data set by the driver in <intr.c>. The application gets it from io-char via a devctl().

highwater

Set by the driver and used by io-char to determine when to invoke flow control. (Make sure this value is LESS than the input buffer size).

baud

The device's baud rate.

winsize

Used only by io-char.

obuf

The output buffer.

ibuf

The input buffer.

cbuf

The canonical buffer.

notify

The notify list. It implements iofunc_notify_trigger() resource manager information. The following arguments are used:

• notify[0] -- notify for input used by io-char
• notify[1] -- notify for output to the driver, <tto.c>
• notify[2] -- notify for data that out-of=band to the driver, <intr.c>

extra

Used for PTYs.

waiting_open

The queue to store blocking clients waiting to open.

io_devctlext

Custom devctl command.

name

The device's name i.e. /dev/ser1

Classification:

QNX Neutrino

See also:

TTYCTRL