From e8d3e08098fe901a6c41709a1f15cd0d4e1726f6 Mon Sep 17 00:00:00 2001
From: Poul-Henning Kamp <phk@FreeBSD.org>
Date: Fri, 17 Sep 2004 11:43:35 +0000
Subject: [PATCH] Add ttyopen and ttyclose functions which will do the right
 stuff for most if not all of our tty drivers in the future.

Centralizing this stuff enables us to remove about 100 lines of
almost but not quite perfectly copy&paste code from each tty driver.
---
 sys/kern/tty.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)

diff --git a/sys/kern/tty.c b/sys/kern/tty.c
index f95b9ffd3272..87c7849a35f0 100644
--- a/sys/kern/tty.c
+++ b/sys/kern/tty.c
@@ -104,6 +104,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/filedesc.h>
 #include <sys/sched.h>
 #include <sys/sysctl.h>
+#include <sys/timepps.h>
 
 #include <vm/vm.h>
 #include <vm/pmap.h>
@@ -2878,6 +2879,102 @@ nottystop(struct tty *tp, int rw)
 	return;
 }
 
+int
+ttyopen(struct cdev *dev, int flag, int mode, struct thread *td)
+{
+	int		error;
+	int		s;
+	struct tty	*tp;
+
+	tp = dev->si_tty;
+	s = spltty();
+	/*
+	 * We jump to this label after all non-interrupted sleeps to pick
+	 * up any changes of the device state.
+	 */
+open_top:
+	if (tp->t_state & TS_GONE)
+		return (ENXIO);
+	error = ttydtrwaitsleep(tp);
+	if (error)
+		goto out;
+	if (tp->t_state & TS_ISOPEN) {
+		/*
+		 * The device is open, so everything has been initialized.
+		 * Handle conflicts.
+		 */
+		if (ISCALLOUT(dev) && !tp->t_actout)
+			return (EBUSY);
+		if (tp->t_actout && !ISCALLOUT(dev)) {
+			if (flag & O_NONBLOCK)
+				return (EBUSY);
+			error =	tsleep(&tp->t_actout,
+				       TTIPRI | PCATCH, "siobi", 0);
+			if (error != 0 || (tp->t_flags & TS_GONE))
+				goto out;
+			goto open_top;
+		}
+		if (tp->t_state & TS_XCLUDE && suser(td))
+			return (EBUSY);
+	} else {
+		/*
+		 * The device isn't open, so there are no conflicts.
+		 * Initialize it.  Initialization is done twice in many
+		 * cases: to preempt sleeping callin opens if we are
+		 * callout, and to complete a callin open after DCD rises.
+		 */
+		tp->t_termios = ISCALLOUT(dev) ? tp->t_init_out : tp->t_init_in;
+		tp->t_modem(tp, SER_DTR | SER_RTS, 0);
+		++tp->t_wopeners;
+		error = tp->t_param(tp, &tp->t_termios);
+		--tp->t_wopeners;
+		if (error == 0 && tp->t_open != NULL)
+			error = tp->t_open(tp, dev);
+		if (error != 0)
+			goto out;
+		if (ISCALLOUT(dev) || (tp->t_modem(tp, 0, 0) & SER_DCD))
+			ttyld_modem(tp, 1);
+	}
+	/*
+	 * Wait for DCD if necessary.
+	 */
+	if (!(tp->t_state & TS_CARR_ON) && !ISCALLOUT(dev)
+	    && !(tp->t_cflag & CLOCAL) && !(flag & O_NONBLOCK)) {
+		++tp->t_wopeners;
+		error = tsleep(TSA_CARR_ON(tp), TTIPRI | PCATCH, "ttydcd", 0);
+		--tp->t_wopeners;
+		if (error != 0 || (tp->t_state & TS_GONE))
+			goto out;
+		goto open_top;
+	}
+	error =	ttyld_open(tp, dev);
+	ttyldoptim(tp);
+	if (tp->t_state & TS_ISOPEN && ISCALLOUT(dev))
+		tp->t_actout = TRUE;
+out:
+	splx(s);
+	if (!(tp->t_state & TS_ISOPEN) && tp->t_wopeners == 0)
+		tp->t_close(tp);
+	return (error);
+}
+
+int
+ttyclose(struct cdev *dev, int flag, int mode, struct thread *td)
+{
+	struct tty *tp;
+
+	tp = dev->si_tty;
+	ttyld_close(tp, flag);
+	ttyldoptim(tp);
+	tp->t_close(tp);
+	tty_close(tp);
+	tp->t_do_timestamp = 0;
+	if (tp->t_pps != NULL)
+		tp->t_pps->ppsparam.mode = 0;
+	return (0);
+}
+
+
 int
 ttyread(struct cdev *dev, struct uio *uio, int flag)
 {