xref: /netbsd-src/sys/arch/sun2/dev/zs.c (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0)
1 /*	$NetBSD: zs.c,v 1.7 2003/01/28 12:35:37 pk Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Gordon W. Ross.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Zilog Z8530 Dual UART driver (machine-dependent part)
41  *
42  * Runs two serial lines per chip using slave drivers.
43  * Plain tty/async lines use the zs_async slave.
44  * Sun keyboard/mouse uses the zs_kbd/zs_ms slaves.
45  */
46 
47 #include "opt_ddb.h"
48 #include "opt_kgdb.h"
49 
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/conf.h>
53 #include <sys/device.h>
54 #include <sys/file.h>
55 #include <sys/ioctl.h>
56 #include <sys/kernel.h>
57 #include <sys/proc.h>
58 #include <sys/tty.h>
59 #include <sys/time.h>
60 #include <sys/syslog.h>
61 
62 #include <machine/autoconf.h>
63 #include <machine/promlib.h>
64 #include <machine/cpu.h>
65 #include <machine/eeprom.h>
66 #include <machine/psl.h>
67 #include <machine/z8530var.h>
68 
69 #include <dev/cons.h>
70 #include <dev/ic/z8530reg.h>
71 #include <dev/sun/kbd_ms_ttyvar.h>
72 #include <ddb/db_output.h>
73 
74 #include <sun2/dev/cons.h>
75 
76 #include "kbd.h"	/* NKBD */
77 #include "ms.h"		/* NMS */
78 
79 /*
80  * Some warts needed by z8530tty.c -
81  * The default parity REALLY needs to be the same as the PROM uses,
82  * or you can not see messages done with printf during boot-up...
83  */
84 int zs_def_cflag = (CREAD | CS8 | HUPCL);
85 
86 /* ZS channel used as the console device (if any) */
87 void *zs_conschan_get, *zs_conschan_put;
88 
89 static u_char zs_init_reg[16] = {
90 	0,	/* 0: CMD (reset, etc.) */
91 	0,	/* 1: No interrupts yet. */
92 #ifdef  ZS_INIT_IVECT
93 	ZS_INIT_IVECT,	/* 2: IVECT */
94 #else
95 	0,	/* 2: IVECT */
96 #endif
97 	ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
98 	ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
99 	ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
100 	0,	/* 6: TXSYNC/SYNCLO */
101 	0,	/* 7: RXSYNC/SYNCHI */
102 	0,	/* 8: alias for data port */
103 #ifdef  ZS_INIT_IVECT
104 	ZSWR9_MASTER_IE,
105 #else
106 	ZSWR9_MASTER_IE | ZSWR9_NO_VECTOR,
107 #endif
108 	0,	/*10: Misc. TX/RX control bits */
109 	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
110 	((PCLK/32)/9600)-2,	/*12: BAUDLO (default=9600) */
111 	0,			/*13: BAUDHI (default=9600) */
112 	ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK,
113 	ZSWR15_BREAK_IE,
114 };
115 
116 /* Console ops */
117 static int  zscngetc __P((dev_t));
118 static void zscnputc __P((dev_t, int));
119 static void zscnpollc __P((dev_t, int));
120 
121 struct consdev zs_consdev = {
122 	NULL,
123 	NULL,
124 	zscngetc,
125 	zscnputc,
126 	zscnpollc,
127 	NULL,
128 };
129 
130 
131 /****************************************************************
132  * Autoconfig
133  ****************************************************************/
134 
135 static int  zs_print __P((void *, const char *name));
136 
137 extern struct cfdriver zs_cd;
138 
139 /* Interrupt handlers. */
140 int zscheckintr __P((void *));
141 static int zshard __P((void *));
142 static void zssoft __P((void *));
143 
144 static int zs_get_speed __P((struct zs_chanstate *));
145 
146 /*
147  * Attach a found zs.
148  *
149  * USE ROM PROPERTIES port-a-ignore-cd AND port-b-ignore-cd FOR
150  * SOFT CARRIER, AND keyboard PROPERTY FOR KEYBOARD/MOUSE?
151  */
152 void
153 zs_attach(zsc, zsd, pri)
154 	struct zsc_softc *zsc;
155 	struct zsdevice *zsd;
156 	int pri;
157 {
158 	struct zsc_attach_args zsc_args;
159 	struct zs_chanstate *cs;
160 	int s, channel, softpri = IPL_SOFTSERIAL;
161 
162 	if (zsd == NULL) {
163 		printf("configuration incomplete\n");
164 		return;
165 	}
166 
167 	printf(" softpri %d\n", softpri);
168 
169 	/*
170 	 * Initialize software state for each channel.
171 	 */
172 	for (channel = 0; channel < 2; channel++) {
173 		struct zschan *zc;
174 		struct device *child;
175 
176 		zsc_args.channel = channel;
177 		cs = &zsc->zsc_cs_store[channel];
178 		zsc->zsc_cs[channel] = cs;
179 
180 		simple_lock_init(&cs->cs_lock);
181 		cs->cs_channel = channel;
182 		cs->cs_private = NULL;
183 		cs->cs_ops = &zsops_null;
184 		cs->cs_brg_clk = PCLK / 16;
185 
186 		zc = (channel == 0) ? &zsd->zs_chan_a : &zsd->zs_chan_b;
187 
188 		zsc_args.consdev = NULL;
189 		zsc_args.hwflags = zs_console_flags(zsc->zsc_promunit,
190 						    zsc->zsc_node,
191 						    channel);
192 
193 		if (zsc_args.hwflags & ZS_HWFLAG_CONSOLE) {
194 			zsc_args.hwflags |= ZS_HWFLAG_USE_CONSDEV;
195 			zsc_args.consdev = &zs_consdev;
196 		}
197 
198 		if ((zsc_args.hwflags & ZS_HWFLAG_CONSOLE_INPUT) != 0) {
199 			zs_conschan_get = zc;
200 		}
201 		if ((zsc_args.hwflags & ZS_HWFLAG_CONSOLE_OUTPUT) != 0) {
202 			zs_conschan_put = zc;
203 		}
204 
205 		/* Children need to set cn_dev, etc */
206 		cs->cs_reg_csr  = &zc->zc_csr;
207 		cs->cs_reg_data = &zc->zc_data;
208 
209 		memcpy(cs->cs_creg, zs_init_reg, 16);
210 		memcpy(cs->cs_preg, zs_init_reg, 16);
211 
212 		/* XXX: Consult PROM properties for this?! */
213 		cs->cs_defspeed = zs_get_speed(cs);
214 		cs->cs_defcflag = zs_def_cflag;
215 
216 		/* Make these correspond to cs_defcflag (-crtscts) */
217 		cs->cs_rr0_dcd = ZSRR0_DCD;
218 		cs->cs_rr0_cts = 0;
219 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
220 		cs->cs_wr5_rts = 0;
221 
222 		/*
223 		 * Clear the master interrupt enable.
224 		 * The INTENA is common to both channels,
225 		 * so just do it on the A channel.
226 		 */
227 		if (channel == 0) {
228 			zs_write_reg(cs, 9, 0);
229 		}
230 
231 		/*
232 		 * Look for a child driver for this channel.
233 		 * The child attach will setup the hardware.
234 		 */
235 		if (!(child =
236 		      config_found(&zsc->zsc_dev, (void *)&zsc_args, zs_print))) {
237 			/* No sub-driver.  Just reset it. */
238 			u_char reset = (channel == 0) ?
239 				ZSWR9_A_RESET : ZSWR9_B_RESET;
240 			s = splzs();
241 			zs_write_reg(cs,  9, reset);
242 			splx(s);
243 		}
244 #if (NKBD > 0) || (NMS > 0)
245 		/*
246 		 * If this was a zstty it has a keyboard
247 		 * property on it we need to attach the
248 		 * sunkbd and sunms line disciplines.
249 		 */
250 		if (child
251 		    && (!strcmp(child->dv_cfdata->cf_name,
252 		    		"zstty"))) {
253 			struct kbd_ms_tty_attach_args kma;
254 			struct zstty_softc {
255 				/* The following are the only fields we need here */
256 				struct	device zst_dev;
257 				struct  tty *zst_tty;
258 				struct	zs_chanstate *zst_cs;
259 			} *zst = (struct zstty_softc *)child;
260 			struct tty *tp;
261 
262 			kma.kmta_tp = tp = zst->zst_tty;
263 			if (tp != NULL) {
264 				kma.kmta_dev = tp->t_dev;
265 				kma.kmta_consdev = zsc_args.consdev;
266 
267 				/* Attach 'em if we got 'em. */
268 				switch(zs_peripheral_type(zsc->zsc_promunit,
269 						 	  zsc->zsc_node,
270 						  	  channel)) {
271 				case ZS_PERIPHERAL_SUNKBD:
272 #if (NKBD > 0)
273 					kma.kmta_name = "keyboard";
274 					config_found(child, (void *)&kma, NULL);
275 #endif
276 					break;
277 				case ZS_PERIPHERAL_SUNMS:
278 #if (NMS > 0)
279 					kma.kmta_name = "mouse";
280 					config_found(child, (void *)&kma, NULL);
281 #endif
282 					break;
283 				default:
284 					break;
285 				}
286 			}
287 		}
288 #endif
289 	}
290 
291 	/*
292 	 * Now safe to install interrupt handlers.  Note the arguments
293 	 * to the interrupt handlers aren't used.  Note, we only do this
294 	 * once since both SCCs interrupt at the same level and vector.
295 	 */
296 	bus_intr_establish(zsc->zsc_bustag, pri, IPL_SERIAL, 0, zshard, zsc);
297 	if (!(zsc->zsc_softintr = softintr_establish(softpri, zssoft, zsc)))
298 		panic("zsattach: could not establish soft interrupt");
299 
300 	evcnt_attach_dynamic(&zsc->zsc_intrcnt, EVCNT_TYPE_INTR, NULL,
301 	    zsc->zsc_dev.dv_xname, "intr");
302 
303 
304 	/*
305 	 * Set the master interrupt enable and interrupt vector.
306 	 * (common to both channels, do it on A)
307 	 */
308 	cs = zsc->zsc_cs[0];
309 	s = splhigh();
310 	/* interrupt vector */
311 	zs_write_reg(cs, 2, zs_init_reg[2]);
312 	/* master interrupt control (enable) */
313 	zs_write_reg(cs, 9, zs_init_reg[9]);
314 	splx(s);
315 
316 }
317 
318 static int
319 zs_print(aux, name)
320 	void *aux;
321 	const char *name;
322 {
323 	struct zsc_attach_args *args = aux;
324 
325 	if (name != NULL)
326 		aprint_normal("%s: ", name);
327 
328 	if (args->channel != -1)
329 		aprint_normal(" channel %d", args->channel);
330 
331 	return (UNCONF);
332 }
333 
334 static int
335 zshard(arg)
336 	void *arg;
337 {
338 	struct zsc_softc *zsc = (struct zsc_softc *)arg;
339 	int rr3, rval;
340 
341 	rval = 0;
342 	while ((rr3 = zsc_intr_hard(zsc))) {
343 		/* Count up the interrupts. */
344 		rval |= rr3;
345 		zsc->zsc_intrcnt.ev_count++;
346 	}
347 	if (((zsc->zsc_cs[0] && zsc->zsc_cs[0]->cs_softreq) ||
348 	     (zsc->zsc_cs[1] && zsc->zsc_cs[1]->cs_softreq)) &&
349 	    zsc->zsc_softintr) {
350 		softintr_schedule(zsc->zsc_softintr);
351 	}
352 	return (rval);
353 }
354 
355 int
356 zscheckintr(arg)
357 	void *arg;
358 {
359 	struct zsc_softc *zsc;
360 	int unit, rval;
361 
362 	rval = 0;
363 	for (unit = 0; unit < zs_cd.cd_ndevs; unit++) {
364 
365 		zsc = zs_cd.cd_devs[unit];
366 		if (zsc == NULL)
367 			continue;
368 		rval = (zshard((void *)zsc) || rval);
369 	}
370 	return (rval);
371 }
372 
373 
374 /*
375  * We need this only for TTY_DEBUG purposes.
376  */
377 static void
378 zssoft(arg)
379 	void *arg;
380 {
381 	struct zsc_softc *zsc = (struct zsc_softc *)arg;
382 	int s;
383 
384 	/* Make sure we call the tty layer at spltty. */
385 	s = spltty();
386 	(void)zsc_intr_soft(zsc);
387 #ifdef TTY_DEBUG
388 	{
389 		struct zstty_softc *zst0 = zsc->zsc_cs[0]->cs_private;
390 		struct zstty_softc *zst1 = zsc->zsc_cs[1]->cs_private;
391 		if (zst0->zst_overflows || zst1->zst_overflows ) {
392 			struct trapframe *frame = (struct trapframe *)arg;
393 
394 			printf("zs silo overflow from %p\n",
395 			       (long)frame->tf_pc);
396 		}
397 	}
398 #endif
399 	splx(s);
400 }
401 
402 
403 /*
404  * Compute the current baud rate given a ZS channel.
405  */
406 static int
407 zs_get_speed(cs)
408 	struct zs_chanstate *cs;
409 {
410 	int tconst;
411 
412 	tconst = zs_read_reg(cs, 12);
413 	tconst |= zs_read_reg(cs, 13) << 8;
414 	return (TCONST_TO_BPS(cs->cs_brg_clk, tconst));
415 }
416 
417 /*
418  * MD functions for setting the baud rate and control modes.
419  */
420 int
421 zs_set_speed(cs, bps)
422 	struct zs_chanstate *cs;
423 	int bps;	/* bits per second */
424 {
425 	int tconst, real_bps;
426 
427 	if (bps == 0)
428 		return (0);
429 
430 #ifdef	DIAGNOSTIC
431 	if (cs->cs_brg_clk == 0)
432 		panic("zs_set_speed");
433 #endif
434 
435 	tconst = BPS_TO_TCONST(cs->cs_brg_clk, bps);
436 	if (tconst < 0)
437 		return (EINVAL);
438 
439 	/* Convert back to make sure we can do it. */
440 	real_bps = TCONST_TO_BPS(cs->cs_brg_clk, tconst);
441 
442 	/* XXX - Allow some tolerance here? */
443 	if (real_bps != bps)
444 		return (EINVAL);
445 
446 	cs->cs_preg[12] = tconst;
447 	cs->cs_preg[13] = tconst >> 8;
448 
449 	/* Caller will stuff the pending registers. */
450 	return (0);
451 }
452 
453 int
454 zs_set_modes(cs, cflag)
455 	struct zs_chanstate *cs;
456 	int cflag;	/* bits per second */
457 {
458 	int s;
459 
460 	/*
461 	 * Output hardware flow control on the chip is horrendous:
462 	 * if carrier detect drops, the receiver is disabled, and if
463 	 * CTS drops, the transmitter is stoped IN MID CHARACTER!
464 	 * Therefore, NEVER set the HFC bit, and instead use the
465 	 * status interrupt to detect CTS changes.
466 	 */
467 	s = splzs();
468 	cs->cs_rr0_pps = 0;
469 	if ((cflag & (CLOCAL | MDMBUF)) != 0) {
470 		cs->cs_rr0_dcd = 0;
471 		if ((cflag & MDMBUF) == 0)
472 			cs->cs_rr0_pps = ZSRR0_DCD;
473 	} else
474 		cs->cs_rr0_dcd = ZSRR0_DCD;
475 	if ((cflag & CRTSCTS) != 0) {
476 		cs->cs_wr5_dtr = ZSWR5_DTR;
477 		cs->cs_wr5_rts = ZSWR5_RTS;
478 		cs->cs_rr0_cts = ZSRR0_CTS;
479 	} else if ((cflag & CDTRCTS) != 0) {
480 		cs->cs_wr5_dtr = 0;
481 		cs->cs_wr5_rts = ZSWR5_DTR;
482 		cs->cs_rr0_cts = ZSRR0_CTS;
483 	} else if ((cflag & MDMBUF) != 0) {
484 		cs->cs_wr5_dtr = 0;
485 		cs->cs_wr5_rts = ZSWR5_DTR;
486 		cs->cs_rr0_cts = ZSRR0_DCD;
487 	} else {
488 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
489 		cs->cs_wr5_rts = 0;
490 		cs->cs_rr0_cts = 0;
491 	}
492 	splx(s);
493 
494 	/* Caller will stuff the pending registers. */
495 	return (0);
496 }
497 
498 
499 /*
500  * Read or write the chip with suitable delays.
501  */
502 
503 u_char
504 zs_read_reg(cs, reg)
505 	struct zs_chanstate *cs;
506 	u_char reg;
507 {
508 	u_char val;
509 
510 	*cs->cs_reg_csr = reg;
511 	ZS_DELAY();
512 	val = *cs->cs_reg_csr;
513 	ZS_DELAY();
514 	return (val);
515 }
516 
517 void
518 zs_write_reg(cs, reg, val)
519 	struct zs_chanstate *cs;
520 	u_char reg, val;
521 {
522 	*cs->cs_reg_csr = reg;
523 	ZS_DELAY();
524 	*cs->cs_reg_csr = val;
525 	ZS_DELAY();
526 }
527 
528 u_char
529 zs_read_csr(cs)
530 	struct zs_chanstate *cs;
531 {
532 	u_char val;
533 
534 	val = *cs->cs_reg_csr;
535 	ZS_DELAY();
536 	return (val);
537 }
538 
539 void  zs_write_csr(cs, val)
540 	struct zs_chanstate *cs;
541 	u_char val;
542 {
543 	*cs->cs_reg_csr = val;
544 	ZS_DELAY();
545 }
546 
547 u_char zs_read_data(cs)
548 	struct zs_chanstate *cs;
549 {
550 	u_char val;
551 
552 	val = *cs->cs_reg_data;
553 	ZS_DELAY();
554 	return (val);
555 }
556 
557 void  zs_write_data(cs, val)
558 	struct zs_chanstate *cs;
559 	u_char val;
560 {
561 	*cs->cs_reg_data = val;
562 	ZS_DELAY();
563 }
564 
565 /****************************************************************
566  * Console support functions (Sun specific!)
567  * Note: this code is allowed to know about the layout of
568  * the chip registers, and uses that to keep things simple.
569  * XXX - I think I like the mvme167 code better. -gwr
570  ****************************************************************/
571 
572 extern void Debugger __P((void));
573 
574 /*
575  * Handle user request to enter kernel debugger.
576  */
577 void
578 zs_abort(cs)
579 	struct zs_chanstate *cs;
580 {
581 	volatile struct zschan *zc = zs_conschan_get;
582 	int rr0;
583 
584 	/* Wait for end of break to avoid PROM abort. */
585 	/* XXX - Limit the wait? */
586 	do {
587 		rr0 = zc->zc_csr;
588 		ZS_DELAY();
589 	} while (rr0 & ZSRR0_BREAK);
590 
591 #if defined(KGDB)
592 	zskgdb(cs);
593 #elif defined(DDB)
594 	{
595 		extern int db_active;
596 
597 		if (!db_active)
598 			Debugger();
599 		else
600 			/* Debugger is probably hozed */
601 			callrom();
602 	}
603 #else
604 	printf("stopping on keyboard abort\n");
605 	callrom();
606 #endif
607 }
608 
609 
610 /*
611  * Polled input char.
612  */
613 int
614 zs_getc(arg)
615 	void *arg;
616 {
617 	volatile struct zschan *zc = arg;
618 	int s, c, rr0;
619 
620 	s = splhigh();
621 	/* Wait for a character to arrive. */
622 	do {
623 		rr0 = zc->zc_csr;
624 		ZS_DELAY();
625 	} while ((rr0 & ZSRR0_RX_READY) == 0);
626 
627 	c = zc->zc_data;
628 	ZS_DELAY();
629 	splx(s);
630 
631 	/*
632 	 * This is used by the kd driver to read scan codes,
633 	 * so don't translate '\r' ==> '\n' here...
634 	 */
635 	return (c);
636 }
637 
638 /*
639  * Polled output char.
640  */
641 void
642 zs_putc(arg, c)
643 	void *arg;
644 	int c;
645 {
646 	volatile struct zschan *zc = arg;
647 	int s, rr0;
648 
649 	s = splhigh();
650 
651 	/* Wait for transmitter to become ready. */
652 	do {
653 		rr0 = zc->zc_csr;
654 		ZS_DELAY();
655 	} while ((rr0 & ZSRR0_TX_READY) == 0);
656 
657 	/*
658 	 * Send the next character.
659 	 * Now you'd think that this could be followed by a ZS_DELAY()
660 	 * just like all the other chip accesses, but it turns out that
661 	 * the `transmit-ready' interrupt isn't de-asserted until
662 	 * some period of time after the register write completes
663 	 * (more than a couple instructions).  So to avoid stray
664 	 * interrupts we put in the 2us delay regardless of cpu model.
665 	 */
666 	zc->zc_data = c;
667 	delay(2);
668 
669 	splx(s);
670 }
671 
672 /*****************************************************************/
673 
674 
675 
676 
677 /*
678  * Polled console input putchar.
679  */
680 static int
681 zscngetc(dev)
682 	dev_t dev;
683 {
684 	return (zs_getc(zs_conschan_get));
685 }
686 
687 /*
688  * Polled console output putchar.
689  */
690 static void
691 zscnputc(dev, c)
692 	dev_t dev;
693 	int c;
694 {
695 	zs_putc(zs_conschan_put, c);
696 }
697 
698 int swallow_zsintrs;
699 
700 static void
701 zscnpollc(dev, on)
702 	dev_t dev;
703 	int on;
704 {
705 	/*
706 	 * Need to tell zs driver to acknowledge all interrupts or we get
707 	 * annoying spurious interrupt messages.  This is because mucking
708 	 * with spl() levels during polling does not prevent interrupts from
709 	 * being generated.
710 	 */
711 
712 	if (on) swallow_zsintrs++;
713 	else swallow_zsintrs--;
714 }
715 
716