xref: /freebsd/sys/dev/uart/uart_tty.c (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2003 Marcel Moolenaar
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/bus.h>
32 #include <sys/conf.h>
33 #include <sys/cons.h>
34 #include <sys/fcntl.h>
35 #include <sys/interrupt.h>
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
38 #include <sys/reboot.h>
39 #include <machine/bus.h>
40 #include <sys/rman.h>
41 #include <sys/tty.h>
42 #include <machine/resource.h>
43 #include <machine/stdarg.h>
44 
45 #include <dev/uart/uart.h>
46 #include <dev/uart/uart_bus.h>
47 #include <dev/uart/uart_cpu.h>
48 
49 #include "uart_if.h"
50 
51 static cn_probe_t uart_cnprobe;
52 static cn_init_t uart_cninit;
53 static cn_init_t uart_cnresume;
54 static cn_term_t uart_cnterm;
55 static cn_getc_t uart_cngetc;
56 static cn_putc_t uart_cnputc;
57 static cn_grab_t uart_cngrab;
58 static cn_ungrab_t uart_cnungrab;
59 
60 static tsw_open_t uart_tty_open;
61 static tsw_close_t uart_tty_close;
62 static tsw_outwakeup_t uart_tty_outwakeup;
63 static tsw_inwakeup_t uart_tty_inwakeup;
64 static tsw_ioctl_t uart_tty_ioctl;
65 static tsw_param_t uart_tty_param;
66 static tsw_modem_t uart_tty_modem;
67 static tsw_free_t uart_tty_free;
68 static tsw_busy_t uart_tty_busy;
69 
70 CONSOLE_DRIVER(
71 	uart,
72 	.cn_resume = uart_cnresume,
73 );
74 
75 static struct uart_devinfo uart_console;
76 
77 /* TTY swi(9) event. Allows all uart soft handlers to share one ithread. */
78 static struct intr_event *tty_intr_event;
79 
80 static void
81 uart_cnprobe(struct consdev *cp)
82 {
83 
84 	cp->cn_pri = CN_DEAD;
85 
86 	KASSERT(uart_console.cookie == NULL, ("foo"));
87 
88 	if (uart_cpu_getdev(UART_DEV_CONSOLE, &uart_console))
89 		return;
90 
91 	if (uart_probe(&uart_console))
92 		return;
93 
94 	strlcpy(cp->cn_name, uart_driver_name, sizeof(cp->cn_name));
95 	cp->cn_pri = (boothowto & RB_SERIAL) ? CN_REMOTE : CN_NORMAL;
96 	cp->cn_arg = &uart_console;
97 }
98 
99 static void
100 uart_cninit(struct consdev *cp)
101 {
102 	struct uart_devinfo *di;
103 
104 	/*
105 	 * Yedi trick: we need to be able to define cn_dev before we go
106 	 * single- or multi-user. The problem is that we don't know at
107 	 * this time what the device will be. Hence, we need to link from
108 	 * the uart_devinfo to the consdev that corresponds to it so that
109 	 * we can define cn_dev in uart_bus_attach() when we find the
110 	 * device during bus enumeration. That's when we'll know what the
111 	 * the unit number will be.
112 	 */
113 	di = cp->cn_arg;
114 	KASSERT(di->cookie == NULL, ("foo"));
115 	di->cookie = cp;
116 	di->type = UART_DEV_CONSOLE;
117 	uart_add_sysdev(di);
118 	uart_init(di);
119 }
120 
121 static void
122 uart_cnresume(struct consdev *cp)
123 {
124 
125 	uart_init(cp->cn_arg);
126 }
127 
128 static void
129 uart_cnterm(struct consdev *cp)
130 {
131 
132 	uart_term(cp->cn_arg);
133 }
134 
135 static void
136 uart_cngrab(struct consdev *cp)
137 {
138 
139 	uart_grab(cp->cn_arg);
140 }
141 
142 static void
143 uart_cnungrab(struct consdev *cp)
144 {
145 
146 	uart_ungrab(cp->cn_arg);
147 }
148 
149 static void
150 uart_cnputc(struct consdev *cp, int c)
151 {
152 
153 	uart_putc(cp->cn_arg, c);
154 }
155 
156 static int
157 uart_cngetc(struct consdev *cp)
158 {
159 
160 	return (uart_poll(cp->cn_arg));
161 }
162 
163 static int
164 uart_tty_open(struct tty *tp)
165 {
166 	struct uart_softc *sc;
167 
168 	sc = tty_softc(tp);
169 
170 	if (sc == NULL || sc->sc_leaving)
171 		return (ENXIO);
172 
173 	sc->sc_opened = 1;
174 	return (0);
175 }
176 
177 static void
178 uart_tty_close(struct tty *tp)
179 {
180 	struct uart_softc *sc;
181 
182 	sc = tty_softc(tp);
183 	if (sc == NULL || sc->sc_leaving || !sc->sc_opened)
184 		return;
185 
186 	if (sc->sc_hwiflow)
187 		UART_IOCTL(sc, UART_IOCTL_IFLOW, 0);
188 	if (sc->sc_hwoflow)
189 		UART_IOCTL(sc, UART_IOCTL_OFLOW, 0);
190 	if (sc->sc_sysdev == NULL)
191 		UART_SETSIG(sc, SER_DDTR | SER_DRTS);
192 
193 	wakeup(sc);
194 	sc->sc_opened = 0;
195 }
196 
197 static void
198 uart_tty_outwakeup(struct tty *tp)
199 {
200 	struct uart_softc *sc;
201 
202 	sc = tty_softc(tp);
203 	if (sc == NULL || sc->sc_leaving)
204 		return;
205 
206 	if (sc->sc_txbusy)
207 		return;
208 
209 	/*
210 	 * Respect RTS/CTS (output) flow control if enabled and not already
211 	 * handled by hardware.
212 	 */
213 	if ((tp->t_termios.c_cflag & CCTS_OFLOW) && !sc->sc_hwoflow &&
214 	    !(sc->sc_hwsig & SER_CTS))
215 		return;
216 
217 	sc->sc_txdatasz = ttydisc_getc(tp, sc->sc_txbuf, sc->sc_txfifosz);
218 	if (sc->sc_txdatasz != 0)
219 		UART_TRANSMIT(sc);
220 }
221 
222 static void
223 uart_tty_inwakeup(struct tty *tp)
224 {
225 	struct uart_softc *sc;
226 
227 	sc = tty_softc(tp);
228 	if (sc == NULL || sc->sc_leaving)
229 		return;
230 
231 	if (sc->sc_isquelch) {
232 		if ((tp->t_termios.c_cflag & CRTS_IFLOW) && !sc->sc_hwiflow)
233 			UART_SETSIG(sc, SER_DRTS|SER_RTS);
234 		sc->sc_isquelch = 0;
235 		uart_sched_softih(sc, SER_INT_RXREADY);
236 	}
237 }
238 
239 static int
240 uart_tty_ioctl(struct tty *tp, u_long cmd, caddr_t data,
241     struct thread *td __unused)
242 {
243 	struct uart_softc *sc;
244 
245 	sc = tty_softc(tp);
246 
247 	switch (cmd) {
248 	case TIOCSBRK:
249 		UART_IOCTL(sc, UART_IOCTL_BREAK, 1);
250 		return (0);
251 	case TIOCCBRK:
252 		UART_IOCTL(sc, UART_IOCTL_BREAK, 0);
253 		return (0);
254 	default:
255 		return pps_ioctl(cmd, data, &sc->sc_pps);
256 	}
257 }
258 
259 static int
260 uart_tty_param(struct tty *tp, struct termios *t)
261 {
262 	struct uart_softc *sc;
263 	int databits, parity, stopbits;
264 
265 	sc = tty_softc(tp);
266 	if (sc == NULL || sc->sc_leaving)
267 		return (ENODEV);
268 	if (t->c_ispeed != t->c_ospeed && t->c_ospeed != 0)
269 		return (EINVAL);
270 	if (t->c_ospeed == 0) {
271 		UART_SETSIG(sc, SER_DDTR | SER_DRTS);
272 		return (0);
273 	}
274 	switch (t->c_cflag & CSIZE) {
275 	case CS5:	databits = 5; break;
276 	case CS6:	databits = 6; break;
277 	case CS7:	databits = 7; break;
278 	default:	databits = 8; break;
279 	}
280 	stopbits = (t->c_cflag & CSTOPB) ? 2 : 1;
281 	if (t->c_cflag & PARENB)
282 		parity = (t->c_cflag & PARODD) ? UART_PARITY_ODD :
283 		    UART_PARITY_EVEN;
284 	else
285 		parity = UART_PARITY_NONE;
286 	if (UART_PARAM(sc, t->c_ospeed, databits, stopbits, parity) != 0)
287 		return (EINVAL);
288 	if ((t->c_cflag & CNO_RTSDTR) == 0)
289 		UART_SETSIG(sc, SER_DDTR | SER_DTR);
290 	/* Set input flow control state. */
291 	if (!sc->sc_hwiflow) {
292 		if ((t->c_cflag & CRTS_IFLOW) && sc->sc_isquelch)
293 			UART_SETSIG(sc, SER_DRTS);
294 		else {
295 			if ((t->c_cflag & CNO_RTSDTR) == 0)
296 				UART_SETSIG(sc, SER_DRTS | SER_RTS);
297 		}
298 	} else
299 		UART_IOCTL(sc, UART_IOCTL_IFLOW, (t->c_cflag & CRTS_IFLOW));
300 	/* Set output flow control state. */
301 	if (sc->sc_hwoflow)
302 		UART_IOCTL(sc, UART_IOCTL_OFLOW, (t->c_cflag & CCTS_OFLOW));
303 
304 	return (0);
305 }
306 
307 static int
308 uart_tty_modem(struct tty *tp, int biton, int bitoff)
309 {
310 	struct uart_softc *sc;
311 
312 	sc = tty_softc(tp);
313 	if (biton != 0 || bitoff != 0)
314 		UART_SETSIG(sc, SER_DELTA(bitoff | biton) | biton);
315 	return (sc->sc_hwsig);
316 }
317 
318 void
319 uart_tty_intr(void *arg)
320 {
321 	struct uart_softc *sc = arg;
322 	struct tty *tp;
323 	int c, err = 0, pend, sig, xc;
324 
325 	if (sc->sc_leaving)
326 		return;
327 
328 	pend = atomic_readandclear_32(&sc->sc_ttypend);
329 	if (!(pend & SER_INT_MASK))
330 		return;
331 
332 	tp = sc->sc_u.u_tty.tp;
333 	tty_lock(tp);
334 
335 	if (pend & SER_INT_RXREADY) {
336 		while (!uart_rx_empty(sc) && !sc->sc_isquelch) {
337 			xc = uart_rx_peek(sc);
338 			c = xc & 0xff;
339 			if (xc & UART_STAT_FRAMERR)
340 				err |= TRE_FRAMING;
341 			if (xc & UART_STAT_OVERRUN)
342 				err |= TRE_OVERRUN;
343 			if (xc & UART_STAT_PARERR)
344 				err |= TRE_PARITY;
345 			if (ttydisc_rint(tp, c, err) != 0) {
346 				sc->sc_isquelch = 1;
347 				if ((tp->t_termios.c_cflag & CRTS_IFLOW) &&
348 				    !sc->sc_hwiflow)
349 					UART_SETSIG(sc, SER_DRTS);
350 			} else
351 				uart_rx_next(sc);
352 		}
353 	}
354 
355 	if (pend & SER_INT_BREAK)
356 		ttydisc_rint(tp, 0, TRE_BREAK);
357 
358 	if (pend & SER_INT_SIGCHG) {
359 		sig = pend & SER_INT_SIGMASK;
360 		if (sig & SER_DDCD)
361 			ttydisc_modem(tp, sig & SER_DCD);
362 		if (sig & SER_DCTS)
363 			uart_tty_outwakeup(tp);
364 	}
365 
366 	if (pend & SER_INT_TXIDLE)
367 		uart_tty_outwakeup(tp);
368 	ttydisc_rint_done(tp);
369 	tty_unlock(tp);
370 }
371 
372 static void
373 uart_tty_free(void *arg __unused)
374 {
375 
376 	/*
377 	 * XXX: uart(4) could reuse the device unit number before it is
378 	 * being freed by the TTY layer. We should use this hook to free
379 	 * the device unit number, but unfortunately newbus does not
380 	 * seem to support such a construct.
381 	 */
382 }
383 
384 static bool
385 uart_tty_busy(struct tty *tp)
386 {
387 	struct uart_softc *sc;
388 
389 	sc = tty_softc(tp);
390 	if (sc == NULL || sc->sc_leaving)
391                 return (false);
392 
393 	/*
394 	 * The tty locking is sufficient here; we may lose the race against
395 	 * uart_bus_ihand()/uart_intr() clearing sc_txbusy underneath us, in
396 	 * which case we will incorrectly but non-fatally report a busy Tx
397 	 * path upward. However, tty locking ensures that no additional output
398 	 * is enqueued before UART_TXBUSY() returns, which means that there
399 	 * are no Tx interrupts to be lost.
400 	 */
401 	if (sc->sc_txbusy)
402 		return (true);
403 	return (UART_TXBUSY(sc));
404 }
405 
406 static struct ttydevsw uart_tty_class = {
407 	.tsw_flags	= TF_INITLOCK|TF_CALLOUT,
408 	.tsw_open	= uart_tty_open,
409 	.tsw_close	= uart_tty_close,
410 	.tsw_outwakeup	= uart_tty_outwakeup,
411 	.tsw_inwakeup	= uart_tty_inwakeup,
412 	.tsw_ioctl	= uart_tty_ioctl,
413 	.tsw_param	= uart_tty_param,
414 	.tsw_modem	= uart_tty_modem,
415 	.tsw_free	= uart_tty_free,
416 	.tsw_busy	= uart_tty_busy,
417 };
418 
419 int
420 uart_tty_attach(struct uart_softc *sc)
421 {
422 	struct tty *tp;
423 	int unit;
424 
425 	sc->sc_u.u_tty.tp = tp = tty_alloc(&uart_tty_class, sc);
426 
427 	unit = device_get_unit(sc->sc_dev);
428 
429 	if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) {
430 		sprintf(((struct consdev *)sc->sc_sysdev->cookie)->cn_name,
431 		    "ttyu%r", unit);
432 		tty_init_console(tp, sc->sc_sysdev->baudrate);
433 	}
434 
435 	swi_add(&tty_intr_event, uart_driver_name, uart_tty_intr, sc, SWI_TTY,
436 	    INTR_TYPE_TTY, &sc->sc_softih);
437 
438 	tty_makedev(tp, NULL, "u%r", unit);
439 
440 	return (0);
441 }
442 
443 int
444 uart_tty_detach(struct uart_softc *sc)
445 {
446 	struct tty *tp;
447 
448 	tp = sc->sc_u.u_tty.tp;
449 
450 	tty_lock(tp);
451 	swi_remove(sc->sc_softih);
452 	tty_rel_gone(tp);
453 
454 	return (0);
455 }
456 
457 struct mtx *
458 uart_tty_getlock(struct uart_softc *sc)
459 {
460 
461 	if (sc->sc_u.u_tty.tp != NULL)
462 		return (tty_getlock(sc->sc_u.u_tty.tp));
463 	else
464 		return (NULL);
465 }
466