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40 * @(#)tty_conf.c 8.4 (Berkeley) 1/21/94
41 * $FreeBSD: src/sys/kern/tty_conf.c,v 1.16.2.1 2002/03/11 01:14:55 dd Exp $
44 #include "opt_compat.h"
46 #include <sys/param.h>
47 #include <sys/systm.h>
55 static l_open_t l_noopen;
56 static l_close_t l_noclose;
57 static l_rint_t l_norint;
58 static l_start_t l_nostart;
61 * XXX it probably doesn't matter what the entries other than the l_open
62 * entry are here. The l_nullioctl and ttymodem entries still look fishy.
63 * Reconsider the removal of nullmodem anyway. It was too much like
64 * ttymodem, but a completely null version might be useful.
67 { l_noopen, l_noclose, l_noread, l_nowrite, \
68 l_nullioctl, l_norint, l_nostart, ttymodem }
70 struct linesw linesw[MAXLDISC] =
73 { ttyopen, ttylclose, ttread, ttwrite,
74 l_nullioctl, ttyinput, ttstart, ttymodem },
75 NODISC(1), /* 1- defunct */
78 { ttyopen, ttylclose, ttread, ttwrite,
79 l_nullioctl, ttyinput, ttstart, ttymodem },
83 NODISC(3), /* loadable */
84 NODISC(4), /* SLIPDISC */
85 NODISC(5), /* PPPDISC */
86 NODISC(6), /* NETGRAPHDISC */
87 NODISC(7), /* loadable */
88 NODISC(8), /* loadable */
91 int nlinesw = NELEM(linesw);
93 static struct linesw nodisc = NODISC(0);
95 #define LOADABLE_LDISC 7
97 * ldisc_register: Register a line discipline.
99 * discipline: Index for discipline to load, or LDISC_LOAD for us to choose.
100 * linesw_p: Pointer to linesw_p.
102 * Returns: Index used or -1 on failure.
105 ldisc_register(int discipline, struct linesw *linesw_p)
109 lwkt_gettoken(&tty_token);
110 if (discipline == LDISC_LOAD) {
112 for (i = LOADABLE_LDISC; i < MAXLDISC; i++)
113 if (bcmp(linesw + i, &nodisc, sizeof(nodisc)) == 0) {
117 else if (discipline >= 0 && discipline < MAXLDISC) {
121 if (slot != -1 && linesw_p)
122 linesw[slot] = *linesw_p;
124 lwkt_reltoken(&tty_token);
129 * ldisc_deregister: Deregister a line discipline obtained with
132 * discipline: Index for discipline to unload.
135 ldisc_deregister(int discipline)
137 lwkt_gettoken(&tty_token);
138 if (discipline < MAXLDISC) {
139 linesw[discipline] = nodisc;
141 lwkt_reltoken(&tty_token);
145 l_noopen(cdev_t dev, struct tty *tp)
152 l_noclose(struct tty *tp, int flag)
159 l_noread(struct tty *tp, struct uio *uio, int flag)
166 l_nowrite(struct tty *tp, struct uio *uio, int flag)
173 l_norint(int c, struct tty *tp)
180 l_nostart(struct tty *tp)
187 * Do nothing specific version of line
188 * discipline specific ioctl command.
191 l_nullioctl(struct tty *tp, u_long cmd, char *data, int flags,