promcons.c revision 1.40 
1/* $NetBSD: promcons.c,v 1.40 2019/08/09 08:05:57 rin Exp $ */
2
3/*
4 * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
5 * All rights reserved.
6 *
7 * Author: Chris G. Demetriou
8 *
9 * Permission to use, copy, modify and distribute this software and
10 * its documentation is hereby granted, provided that both the copyright
11 * notice and this permission notice appear in all copies of the
12 * software, derivative works or modified versions, and any portions
13 * thereof, and that both notices appear in supporting documentation.
14 *
15 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
16 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
17 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
18 *
19 * Carnegie Mellon requests users of this software to return to
20 *
21 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
22 *  School of Computer Science
23 *  Carnegie Mellon University
24 *  Pittsburgh PA 15213-3890
25 *
26 * any improvements or extensions that they make and grant Carnegie the
27 * rights to redistribute these changes.
28 */
29
30#include <sys/cdefs.h>			/* RCS ID & Copyright macro defns */
31
32__KERNEL_RCSID(0, "$NetBSD: promcons.c,v 1.40 2019/08/09 08:05:57 rin Exp $");
33
34#include <sys/param.h>
35#include <sys/systm.h>
36#include <sys/ioctl.h>
37#include <sys/select.h>
38#include <sys/tty.h>
39#include <sys/proc.h>
40#include <sys/file.h>
41#include <sys/uio.h>
42#include <sys/kernel.h>
43#include <sys/syslog.h>
44#include <sys/types.h>
45#include <sys/device.h>
46#include <sys/conf.h>
47#include <sys/kauth.h>
48
49#include <uvm/uvm_extern.h>
50
51#include <machine/cpuconf.h>
52#include <machine/prom.h>
53
54#ifndef CONSPEED
55#define	CONSPEED 9600
56#endif
57
58#ifdef _PMAP_MAY_USE_PROM_CONSOLE
59
60dev_type_open(promopen);
61dev_type_close(promclose);
62dev_type_read(promread);
63dev_type_write(promwrite);
64dev_type_ioctl(promioctl);
65dev_type_stop(promstop);
66dev_type_tty(promtty);
67dev_type_poll(prompoll);
68
69const struct cdevsw prom_cdevsw = {
70	.d_open = promopen,
71	.d_close = promclose,
72	.d_read = promread,
73	.d_write = promwrite,
74	.d_ioctl = promioctl,
75	.d_stop = promstop,
76	.d_tty = promtty,
77	.d_poll = prompoll,
78	.d_mmap = nommap,
79	.d_kqfilter = ttykqfilter,
80	.d_discard = nodiscard,
81	.d_flag = D_TTY
82};
83
84#define	PROM_POLL_HZ	50
85
86static struct  tty *prom_tty[1];
87static int polltime;
88
89void	promstart(struct tty *);
90void	promtimeout(void *);
91int	promparam(struct tty *, struct termios *);
92
93struct callout prom_ch;
94
95int
96promopen(dev_t dev, int flag, int mode, struct lwp *l)
97{
98	int unit = minor(dev);
99	struct tty *tp;
100	int s;
101	int error = 0, setuptimeout = 0;
102	static bool callo;
103
104	if (!callo) {
105		callout_init(&prom_ch, 0);
106		callo = true;
107	}
108
109	if (!pmap_uses_prom_console() || unit >= 1)
110		return ENXIO;
111
112	s = spltty();
113
114	if (!prom_tty[unit]) {
115		tp = prom_tty[unit] = tty_alloc();
116		tty_attach(tp);
117	} else
118		tp = prom_tty[unit];
119
120	tp->t_oproc = promstart;
121	tp->t_param = promparam;
122	tp->t_dev = dev;
123
124	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp)) {
125		splx(s);
126		return (EBUSY);
127	}
128
129	if ((tp->t_state & TS_ISOPEN) == 0) {
130		tp->t_state |= TS_CARR_ON;
131		ttychars(tp);
132		tp->t_iflag = TTYDEF_IFLAG;
133		tp->t_oflag = TTYDEF_OFLAG;
134		tp->t_cflag = TTYDEF_CFLAG|CLOCAL;
135		tp->t_lflag = TTYDEF_LFLAG;
136		tp->t_ispeed = tp->t_ospeed = CONSPEED;
137		ttsetwater(tp);
138
139		setuptimeout = 1;
140	}
141
142	splx(s);
143
144	error = (*tp->t_linesw->l_open)(dev, tp);
145	if (error == 0 && setuptimeout) {
146		polltime = hz / PROM_POLL_HZ;
147		if (polltime < 1)
148			polltime = 1;
149		callout_reset(&prom_ch, polltime, promtimeout, tp);
150	}
151	return error;
152}
153
154int
155promclose(dev_t dev, int flag, int mode, struct lwp *l)
156{
157	int unit = minor(dev);
158	struct tty *tp = prom_tty[unit];
159
160	callout_stop(&prom_ch);
161	(*tp->t_linesw->l_close)(tp, flag);
162	ttyclose(tp);
163	return 0;
164}
165
166int
167promread(dev_t dev, struct uio *uio, int flag)
168{
169	struct tty *tp = prom_tty[minor(dev)];
170
171	return ((*tp->t_linesw->l_read)(tp, uio, flag));
172}
173
174int
175promwrite(dev_t dev, struct uio *uio, int flag)
176{
177	struct tty *tp = prom_tty[minor(dev)];
178
179	return ((*tp->t_linesw->l_write)(tp, uio, flag));
180}
181
182int
183prompoll(dev_t dev, int events, struct lwp *l)
184{
185	struct tty *tp = prom_tty[minor(dev)];
186
187	return ((*tp->t_linesw->l_poll)(tp, events, l));
188}
189
190int
191promioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
192{
193	int unit = minor(dev);
194	struct tty *tp = prom_tty[unit];
195	int error;
196
197	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
198	if (error != EPASSTHROUGH)
199		return error;
200	return ttioctl(tp, cmd, data, flag, l);
201}
202
203int
204promparam(struct tty *tp, struct termios *t)
205{
206
207	return 0;
208}
209
210void
211promstart(struct tty *tp)
212{
213	int s;
214
215	s = spltty();
216	if (tp->t_state & (TS_TTSTOP | TS_BUSY))
217		goto out;
218	ttypull(tp);
219	tp->t_state |= TS_BUSY;
220	while (tp->t_outq.c_cc != 0)
221		promcnputc(tp->t_dev, getc(&tp->t_outq));
222	tp->t_state &= ~TS_BUSY;
223out:
224	splx(s);
225}
226
227/*
228 * Stop output on a line.
229 */
230void
231promstop(struct tty *tp, int flag)
232{
233	int s;
234
235	s = spltty();
236	if (tp->t_state & TS_BUSY)
237		if ((tp->t_state & TS_TTSTOP) == 0)
238			tp->t_state |= TS_FLUSH;
239	splx(s);
240}
241
242void
243promtimeout(void *v)
244{
245	struct tty *tp = v;
246	u_char c;
247
248	while (promcnlookc(tp->t_dev, &c)) {
249		if (tp->t_state & TS_ISOPEN)
250			(*tp->t_linesw->l_rint)(c, tp);
251	}
252	callout_reset(&prom_ch, polltime, promtimeout, tp);
253}
254
255struct tty *
256promtty(dev_t dev)
257{
258
259	if (minor(dev) != 0)
260		panic("promtty: bogus");
261
262	return prom_tty[0];
263}
264
265#else /* _PMAP_MAY_USE_PROM_CONSOLE */
266
267/*
268 * If not defined _PMAP_MAY_USE_PROM_CONSOLE,
269 * this fake prom_cdevsw is attached to the kernel.
270 * NEVER REMOVE!
271 */
272const struct cdevsw prom_cdevsw = {
273	.d_open = noopen,
274	.d_close = noclose,
275	.d_read = noread,
276	.d_write = nowrite,
277	.d_ioctl = noioctl,
278	.d_stop = nostop,
279	.d_tty = notty,
280	.d_poll = nopoll,
281	.d_mmap = nommap,
282	.d_kqfilter = nokqfilter,
283	.d_discard = nodiscard,
284	.d_flag = 0
285};
286
287#endif /* _PMAP_MAY_USE_PROM_CONSOLE */
288