1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
10  * 1. Redistributions of source code must retain the above copyright
35  * Pseudo-nulmodem driver
107 	struct tty *otp;  in nmdm_close()  local
110 	onp = np->np_other;  in nmdm_close()
111 	otp = onp->np_tty;  in nmdm_close()
114 	if (tty_opened(otp))  in nmdm_close()
122 	onp = np->np_other;  in nmdm_close()
125 	otp = onp->np_tty;  in nmdm_close()
126 	tty_rel_gone(otp);  in nmdm_close()
134 	struct nmdmsoftc *ns = np->np_pair;  in nmdm_free()
136 	callout_drain(&np->np_callout);  in nmdm_free()
137 	taskqueue_drain(taskqueue_swi, &np->np_task);  in nmdm_free()
144 	mtx_lock(&ns->ns_mtx);  in nmdm_free()
145 	if (np->np_other != NULL) {  in nmdm_free()
146 		np->np_other->np_other = NULL;  in nmdm_free()
147 		mtx_unlock(&ns->ns_mtx);  in nmdm_free()
150 	mtx_destroy(&ns->ns_mtx);  in nmdm_free()
152 	atomic_subtract_int(&nmdm_count, 1);  in nmdm_free()
173 	end = name + strlen(name) - 1;  in nmdm_clone()
179 	mtx_init(&ns->ns_mtx, "nmdm", NULL, MTX_DEF);  in nmdm_clone()
182 	ns->ns_part1.np_pair = ns;  in nmdm_clone()
183 	ns->ns_part1.np_other = &ns->ns_part2;  in nmdm_clone()
184 	TASK_INIT(&ns->ns_part1.np_task, 0, nmdm_task_tty, &ns->ns_part1);  in nmdm_clone()
185 	callout_init_mtx(&ns->ns_part1.np_callout, &ns->ns_mtx, 0);  in nmdm_clone()
187 	ns->ns_part2.np_pair = ns;  in nmdm_clone()
188 	ns->ns_part2.np_other = &ns->ns_part1;  in nmdm_clone()
189 	TASK_INIT(&ns->ns_part2.np_task, 0, nmdm_task_tty, &ns->ns_part2);  in nmdm_clone()
190 	callout_init_mtx(&ns->ns_part2.np_callout, &ns->ns_mtx, 0);  in nmdm_clone()
193 	tp = ns->ns_part1.np_tty = tty_alloc_mutex(&nmdm_class, &ns->ns_part1,  in nmdm_clone()
194 	    &ns->ns_mtx);  in nmdm_clone()
200 		mtx_destroy(&ns->ns_mtx);  in nmdm_clone()
205 	tp = ns->ns_part2.np_tty = tty_alloc_mutex(&nmdm_class, &ns->ns_part2,  in nmdm_clone()
206 	    &ns->ns_mtx);  in nmdm_clone()
212 		mtx_lock(&ns->ns_mtx);  in nmdm_clone()
214 		ns->ns_part1.np_other = NULL;  in nmdm_clone()
215 		atomic_add_int(&nmdm_count, 1);  in nmdm_clone()
216 		tty_rel_gone(ns->ns_part1.np_tty);  in nmdm_clone()
221 		*dev = ns->ns_part1.np_tty->t_dev;  in nmdm_clone()
223 		*dev = ns->ns_part2.np_tty->t_dev;  in nmdm_clone()
226 	atomic_add_int(&nmdm_count, 1);  in nmdm_clone()
234 	if (np->np_rate == 0)  in nmdm_timeout()
238 	 * Do a simple Floyd-Steinberg dither here to avoid FP math.  in nmdm_timeout()
241 	np->np_accumulator += np->np_credits;  in nmdm_timeout()
242 	np->np_quota = np->np_accumulator >> QS;  in nmdm_timeout()
243 	np->np_accumulator &= ((1 << QS) - 1);  in nmdm_timeout()
245 	taskqueue_enqueue(taskqueue_swi, &np->np_task);  in nmdm_timeout()
246 	callout_reset(&np->np_callout, np->np_rate, nmdm_timeout, np);  in nmdm_timeout()
252 	struct tty *tp, *otp;  in nmdm_task_tty()  local
256 	tp = np->np_tty;  in nmdm_task_tty()
263 	otp = np->np_other->np_tty;  in nmdm_task_tty()
264 	KASSERT(otp != NULL, ("NULL otp in nmdmstart"));  in nmdm_task_tty()
265 	KASSERT(otp != tp, ("NULL otp == tp nmdmstart"));  in nmdm_task_tty()
266 	if (np->np_other->np_dcd) {  in nmdm_task_tty()
268 			np->np_other->np_dcd = 0;  in nmdm_task_tty()
269 			ttydisc_modem(otp, 0);  in nmdm_task_tty()
273 			np->np_other->np_dcd = 1;  in nmdm_task_tty()
274 			ttydisc_modem(otp, 1);  in nmdm_task_tty()
279 	if (tty_gone(otp)) {  in nmdm_task_tty()
280 		tty_unlock(otp);  in nmdm_task_tty()
284 	while (ttydisc_rint_poll(otp) > 0) {  in nmdm_task_tty()
285 		if (np->np_rate && !np->np_quota)  in nmdm_task_tty()
287 		if (ttydisc_getc(tp, &c, 1) != 1)  in nmdm_task_tty()
289 		np->np_quota--;  in nmdm_task_tty()
290 		ttydisc_rint(otp, c, 0);  in nmdm_task_tty()
293 	ttydisc_rint_done(otp);  in nmdm_task_tty()
303 	bits = 1;		/* start bit */  in bits_per_char()
304 	switch (t->c_cflag & CSIZE) {  in bits_per_char()
311 	if (t->c_cflag & PARENB)  in bits_per_char()
313 	if (t->c_cflag & CSTOPB)  in bits_per_char()
325 	tp2 = np->np_other->np_tty;  in nmdm_param()
327 	if (!((t->c_cflag | tp2->t_termios.c_cflag) & CDSR_OFLOW)) {  in nmdm_param()
328 		np->np_rate = 0;  in nmdm_param()
329 		np->np_other->np_rate = 0;  in nmdm_param()
334 	 * DSRFLOW one either side enables rate-simulation for both  in nmdm_param()
340 	bpc = imax(bits_per_char(t), bits_per_char(&tp2->t_termios));  in nmdm_param()
344 		speed = imin(tp2->t_termios.c_ospeed, t->c_ispeed);  in nmdm_param()
346 			np->np_rate = 0;  in nmdm_param()
347 			np->np_other->np_rate = 0;  in nmdm_param()
355 			rate = 1;  in nmdm_param()
360 		np->np_credits = speed;  in nmdm_param()
361 		np->np_rate = rate;  in nmdm_param()
362 		callout_reset(&np->np_callout, rate, nmdm_timeout, np);  in nmdm_param()
368 		np = np->np_other;  in nmdm_param()
369 		t = &tp2->t_termios;  in nmdm_param()
384 			np->np_other->np_dcd = 1;  in nmdm_modem()
386 			np->np_other->np_dcd = 0;  in nmdm_modem()
388 		ttydisc_modem(np->np_other->np_tty, np->np_other->np_dcd);  in nmdm_modem()
392 		if (np->np_dcd)  in nmdm_modem()
394 		if (np->np_other->np_dcd)  in nmdm_modem()
407 	taskqueue_enqueue(taskqueue_swi, &np->np_other->np_task);  in nmdm_inwakeup()
416 	taskqueue_enqueue(taskqueue_swi, &np->np_task);  in nmdm_outwakeup()