summaryrefslogtreecommitdiff
path: root/arch/ia64/hp/sim/simserial.c
blob: fb324b345e886ff2203e8227af70b106fb265c9c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
/*
 * Simulated Serial Driver (fake serial)
 *
 * This driver is mostly used for bringup purposes and will go away.
 * It has a strong dependency on the system console. All outputs
 * are rerouted to the same facility as the one used by printk which, in our
 * case means sys_sim.c console (goes via the simulator). The code hereafter
 * is completely leveraged from the serial.c driver.
 *
 * Copyright (C) 1999-2000, 2002-2003 Hewlett-Packard Co
 *	Stephane Eranian <eranian@hpl.hp.com>
 *	David Mosberger-Tang <davidm@hpl.hp.com>
 *
 * 02/04/00 D. Mosberger	Merged in serial.c bug fixes in rs_close().
 * 02/25/00 D. Mosberger	Synced up with 2.3.99pre-5 version of serial.c.
 * 07/30/02 D. Mosberger	Replace sti()/cli() with explicit spinlocks & local irq masking
 */

#include <linux/init.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/major.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/capability.h>
#include <linux/console.h>
#include <linux/module.h>
#include <linux/serial.h>
#include <linux/serialP.h>
#include <linux/sysrq.h>

#include <asm/irq.h>
#include <asm/hpsim.h>
#include <asm/hw_irq.h>
#include <asm/uaccess.h>

#include "hpsim_ssc.h"

#undef SIMSERIAL_DEBUG	/* define this to get some debug information */

#define KEYBOARD_INTR	3	/* must match with simulator! */

#define NR_PORTS	1	/* only one port for now */

static char *serial_name = "SimSerial driver";
static char *serial_version = "0.6";

/*
 * This has been extracted from asm/serial.h. We need one eventually but
 * I don't know exactly what we're going to put in it so just fake one
 * for now.
 */
#define BASE_BAUD ( 1843200 / 16 )

#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST)

/*
 * Most of the values here are meaningless to this particular driver.
 * However some values must be preserved for the code (leveraged from serial.c
 * to work correctly).
 * port must not be 0
 * type must not be UNKNOWN
 * So I picked arbitrary (guess from where?) values instead
 */
static struct serial_state rs_table[NR_PORTS]={
  /* UART CLK   PORT IRQ     FLAGS        */
  { BASE_BAUD, 0x3F8, 0, STD_COM_FLAGS, PORT_16550 }  /* ttyS0 */
};

/*
 * Just for the fun of it !
 */
static struct serial_uart_config uart_config[] = {
	{ "unknown", 1, 0 },
	{ "8250", 1, 0 },
	{ "16450", 1, 0 },
	{ "16550", 1, 0 },
	{ "16550A", 16, UART_CLEAR_FIFO | UART_USE_FIFO },
	{ "cirrus", 1, 0 },
	{ "ST16650", 1, UART_CLEAR_FIFO | UART_STARTECH },
	{ "ST16650V2", 32, UART_CLEAR_FIFO | UART_USE_FIFO |
		  UART_STARTECH },
	{ "TI16750", 64, UART_CLEAR_FIFO | UART_USE_FIFO},
	{ NULL, 0}
};

struct tty_driver *hp_simserial_driver;

static struct console *console;

static unsigned char *tmp_buf;

extern struct console *console_drivers; /* from kernel/printk.c */

/*
 * ------------------------------------------------------------
 * rs_stop() and rs_start()
 *
 * This routines are called before setting or resetting tty->stopped.
 * They enable or disable transmitter interrupts, as necessary.
 * ------------------------------------------------------------
 */
static void rs_stop(struct tty_struct *tty)
{
#ifdef SIMSERIAL_DEBUG
	printk("rs_stop: tty->stopped=%d tty->hw_stopped=%d tty->flow_stopped=%d\n",
		tty->stopped, tty->hw_stopped, tty->flow_stopped);
#endif

}

static void rs_start(struct tty_struct *tty)
{
#ifdef SIMSERIAL_DEBUG
	printk("rs_start: tty->stopped=%d tty->hw_stopped=%d tty->flow_stopped=%d\n",
		tty->stopped, tty->hw_stopped, tty->flow_stopped);
#endif
}

static  void receive_chars(struct tty_struct *tty)
{
	unsigned char ch;
	static unsigned char seen_esc = 0;

	while ( (ch = ia64_ssc(0, 0, 0, 0, SSC_GETCHAR)) ) {
		if ( ch == 27 && seen_esc == 0 ) {
			seen_esc = 1;
			continue;
		} else {
			if ( seen_esc==1 && ch == 'O' ) {
				seen_esc = 2;
				continue;
			} else if ( seen_esc == 2 ) {
				if ( ch == 'P' ) /* F1 */
					show_state();
#ifdef CONFIG_MAGIC_SYSRQ
				if ( ch == 'S' ) { /* F4 */
					do
						ch = ia64_ssc(0, 0, 0, 0,
							      SSC_GETCHAR);
					while (!ch);
					handle_sysrq(ch);
				}
#endif
				seen_esc = 0;
				continue;
			}
		}
		seen_esc = 0;

		if (tty_insert_flip_char(tty, ch, TTY_NORMAL) == 0)
			break;
	}
	tty_flip_buffer_push(tty);
}

/*
 * This is the serial driver's interrupt routine for a single port
 */
static irqreturn_t rs_interrupt_single(int irq, void *dev_id)
{
	struct serial_state *info = dev_id;

	if (!info->tport.tty) {
		printk(KERN_INFO "simrs_interrupt_single: info|tty=0 info=%p problem\n", info);
		return IRQ_NONE;
	}
	/*
	 * pretty simple in our case, because we only get interrupts
	 * on inbound traffic
	 */
	receive_chars(info->tport.tty);
	return IRQ_HANDLED;
}

/*
 * -------------------------------------------------------------------
 * Here ends the serial interrupt routines.
 * -------------------------------------------------------------------
 */

static int rs_put_char(struct tty_struct *tty, unsigned char ch)
{
	struct serial_state *info = tty->driver_data;
	unsigned long flags;

	if (!tty || !info->xmit.buf)
		return 0;

	local_irq_save(flags);
	if (CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) == 0) {
		local_irq_restore(flags);
		return 0;
	}
	info->xmit.buf[info->xmit.head] = ch;
	info->xmit.head = (info->xmit.head + 1) & (SERIAL_XMIT_SIZE-1);
	local_irq_restore(flags);
	return 1;
}

static void transmit_chars(struct tty_struct *tty, struct serial_state *info,
		int *intr_done)
{
	int count;
	unsigned long flags;

	local_irq_save(flags);

	if (info->x_char) {
		char c = info->x_char;

		console->write(console, &c, 1);

		info->icount.tx++;
		info->x_char = 0;

		goto out;
	}

	if (info->xmit.head == info->xmit.tail || tty->stopped ||
			tty->hw_stopped) {
#ifdef SIMSERIAL_DEBUG
		printk("transmit_chars: head=%d, tail=%d, stopped=%d\n",
		       info->xmit.head, info->xmit.tail, tty->stopped);
#endif
		goto out;
	}
	/*
	 * We removed the loop and try to do it in to chunks. We need
	 * 2 operations maximum because it's a ring buffer.
	 *
	 * First from current to tail if possible.
	 * Then from the beginning of the buffer until necessary
	 */

	count = min(CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE),
		    SERIAL_XMIT_SIZE - info->xmit.tail);
	console->write(console, info->xmit.buf+info->xmit.tail, count);

	info->xmit.tail = (info->xmit.tail+count) & (SERIAL_XMIT_SIZE-1);

	/*
	 * We have more at the beginning of the buffer
	 */
	count = CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
	if (count) {
		console->write(console, info->xmit.buf, count);
		info->xmit.tail += count;
	}
out:
	local_irq_restore(flags);
}

static void rs_flush_chars(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;

	if (info->xmit.head == info->xmit.tail || tty->stopped || tty->hw_stopped ||
	    !info->xmit.buf)
		return;

	transmit_chars(tty, info, NULL);
}


static int rs_write(struct tty_struct * tty,
		    const unsigned char *buf, int count)
{
	struct serial_state *info = tty->driver_data;
	int	c, ret = 0;
	unsigned long flags;

	if (!tty || !info->xmit.buf || !tmp_buf) return 0;

	local_irq_save(flags);
	while (1) {
		c = CIRC_SPACE_TO_END(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
		if (count < c)
			c = count;
		if (c <= 0) {
			break;
		}
		memcpy(info->xmit.buf + info->xmit.head, buf, c);
		info->xmit.head = ((info->xmit.head + c) &
				   (SERIAL_XMIT_SIZE-1));
		buf += c;
		count -= c;
		ret += c;
	}
	local_irq_restore(flags);
	/*
	 * Hey, we transmit directly from here in our case
	 */
	if (CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE)
	    && !tty->stopped && !tty->hw_stopped) {
		transmit_chars(tty, info, NULL);
	}
	return ret;
}

static int rs_write_room(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;

	return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}

static int rs_chars_in_buffer(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;

	return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}

static void rs_flush_buffer(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;
	unsigned long flags;

	local_irq_save(flags);
	info->xmit.head = info->xmit.tail = 0;
	local_irq_restore(flags);

	tty_wakeup(tty);
}

/*
 * This function is used to send a high-priority XON/XOFF character to
 * the device
 */
static void rs_send_xchar(struct tty_struct *tty, char ch)
{
	struct serial_state *info = tty->driver_data;

	info->x_char = ch;
	if (ch) {
		/*
		 * I guess we could call console->write() directly but
		 * let's do that for now.
		 */
		transmit_chars(tty, info, NULL);
	}
}

/*
 * ------------------------------------------------------------
 * rs_throttle()
 *
 * This routine is called by the upper-layer tty layer to signal that
 * incoming characters should be throttled.
 * ------------------------------------------------------------
 */
static void rs_throttle(struct tty_struct * tty)
{
	if (I_IXOFF(tty)) rs_send_xchar(tty, STOP_CHAR(tty));

	printk(KERN_INFO "simrs_throttle called\n");
}

static void rs_unthrottle(struct tty_struct * tty)
{
	struct serial_state *info = tty->driver_data;

	if (I_IXOFF(tty)) {
		if (info->x_char)
			info->x_char = 0;
		else
			rs_send_xchar(tty, START_CHAR(tty));
	}
	printk(KERN_INFO "simrs_unthrottle called\n");
}


static int rs_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
{
	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
	    (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) &&
	    (cmd != TIOCMIWAIT)) {
		if (tty->flags & (1 << TTY_IO_ERROR))
		    return -EIO;
	}

	switch (cmd) {
		case TIOCGSERIAL:
			printk(KERN_INFO "simrs_ioctl TIOCGSERIAL called\n");
			return 0;
		case TIOCSSERIAL:
			printk(KERN_INFO "simrs_ioctl TIOCSSERIAL called\n");
			return 0;
		case TIOCSERCONFIG:
			printk(KERN_INFO "rs_ioctl: TIOCSERCONFIG called\n");
			return -EINVAL;

		case TIOCSERGETLSR: /* Get line status register */
			printk(KERN_INFO "rs_ioctl: TIOCSERGETLSR called\n");
			return  -EINVAL;

		case TIOCSERGSTRUCT:
			printk(KERN_INFO "rs_ioctl: TIOCSERGSTRUCT called\n");
#if 0
			if (copy_to_user((struct async_struct *) arg,
					 info, sizeof(struct async_struct)))
				return -EFAULT;
#endif
			return 0;

		/*
		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
		 * - mask passed in arg for lines of interest
		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
		 * Caller should use TIOCGICOUNT to see which one it was
		 */
		case TIOCMIWAIT:
			printk(KERN_INFO "rs_ioctl: TIOCMIWAIT: called\n");
			return 0;
		case TIOCSERGWILD:
		case TIOCSERSWILD:
			/* "setserial -W" is called in Debian boot */
			printk (KERN_INFO "TIOCSER?WILD ioctl obsolete, ignored.\n");
			return 0;

		default:
			return -ENOIOCTLCMD;
		}
	return 0;
}

#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))

static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
{
	/* Handle turning off CRTSCTS */
	if ((old_termios->c_cflag & CRTSCTS) &&
	    !(tty->termios->c_cflag & CRTSCTS)) {
		tty->hw_stopped = 0;
		rs_start(tty);
	}
}
/*
 * This routine will shutdown a serial port; interrupts are disabled, and
 * DTR is dropped if the hangup on close termio flag is on.
 */
static void shutdown(struct tty_struct *tty, struct serial_state *info)
{
	unsigned long	flags;

	if (!(info->flags & ASYNC_INITIALIZED))
		return;

#ifdef SIMSERIAL_DEBUG
	printk("Shutting down serial port %d (irq %d)...\n", info->line,
	       info->irq);
#endif

	local_irq_save(flags);
	{
		if (info->irq)
			free_irq(info->irq, info);

		if (info->xmit.buf) {
			free_page((unsigned long) info->xmit.buf);
			info->xmit.buf = NULL;
		}

		set_bit(TTY_IO_ERROR, &tty->flags);

		info->flags &= ~ASYNC_INITIALIZED;
	}
	local_irq_restore(flags);
}

/*
 * ------------------------------------------------------------
 * rs_close()
 *
 * This routine is called when the serial port gets closed.  First, we
 * wait for the last remaining data to be sent.  Then, we unlink its
 * async structure from the interrupt chain if necessary, and we free
 * that IRQ if nothing is left in the chain.
 * ------------------------------------------------------------
 */
static void rs_close(struct tty_struct *tty, struct file * filp)
{
	struct serial_state *info = tty->driver_data;
	unsigned long flags;

	if (!info)
		return;

	local_irq_save(flags);
	if (tty_hung_up_p(filp)) {
#ifdef SIMSERIAL_DEBUG
		printk("rs_close: hung_up\n");
#endif
		local_irq_restore(flags);
		return;
	}
#ifdef SIMSERIAL_DEBUG
	printk("rs_close ttys%d, count = %d\n", info->line, info->count);
#endif
	if ((tty->count == 1) && (info->count != 1)) {
		/*
		 * Uh, oh.  tty->count is 1, which means that the tty
		 * structure will be freed.  info->count should always
		 * be one in these conditions.  If it's greater than
		 * one, we've got real problems, since it means the
		 * serial port won't be shutdown.
		 */
		printk(KERN_ERR "rs_close: bad serial port count; tty->count is 1, "
		       "info->count is %d\n", info->count);
		info->count = 1;
	}
	if (--info->count < 0) {
		printk(KERN_ERR "rs_close: bad serial port count for ttys%d: %d\n",
		       info->line, info->count);
		info->count = 0;
	}
	if (info->count) {
		local_irq_restore(flags);
		return;
	}
	info->flags |= ASYNC_CLOSING;
	local_irq_restore(flags);

	/*
	 * Now we wait for the transmit buffer to clear; and we notify
	 * the line discipline to only process XON/XOFF characters.
	 */
	shutdown(tty, info);
	rs_flush_buffer(tty);
	tty_ldisc_flush(tty);
	info->tport.tty = NULL;
	if (info->tport.blocked_open) {
		if (info->tport.close_delay)
			schedule_timeout_interruptible(info->tport.close_delay);
		wake_up_interruptible(&info->tport.open_wait);
	}
	info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
	wake_up_interruptible(&info->tport.close_wait);
}

/*
 * rs_wait_until_sent() --- wait until the transmitter is empty
 */
static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
{
}


/*
 * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
 */
static void rs_hangup(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;

#ifdef SIMSERIAL_DEBUG
	printk("rs_hangup: called\n");
#endif

	rs_flush_buffer(tty);
	if (info->flags & ASYNC_CLOSING)
		return;
	shutdown(tty, info);

	info->count = 0;
	info->flags &= ~ASYNC_NORMAL_ACTIVE;
	info->tport.tty = NULL;
	wake_up_interruptible(&info->tport.open_wait);
}


static int startup(struct tty_struct *tty, struct serial_state *state)
{
	unsigned long flags;
	int	retval=0;
	unsigned long page;

	page = get_zeroed_page(GFP_KERNEL);
	if (!page)
		return -ENOMEM;

	local_irq_save(flags);

	if (state->flags & ASYNC_INITIALIZED) {
		free_page(page);
		goto errout;
	}

	if (!state->port || !state->type) {
		set_bit(TTY_IO_ERROR, &tty->flags);
		free_page(page);
		goto errout;
	}
	if (state->xmit.buf)
		free_page(page);
	else
		state->xmit.buf = (unsigned char *) page;

#ifdef SIMSERIAL_DEBUG
	printk("startup: ttys%d (irq %d)...", state->line, state->irq);
#endif

	/*
	 * Allocate the IRQ if necessary
	 */
	if (state->irq) {
		retval = request_irq(state->irq, rs_interrupt_single, 0,
				"simserial", state);
		if (retval)
			goto errout;
	}

	clear_bit(TTY_IO_ERROR, &tty->flags);

	state->xmit.head = state->xmit.tail = 0;

#if 0
	/*
	 * Set up serial timers...
	 */
	timer_table[RS_TIMER].expires = jiffies + 2*HZ/100;
	timer_active |= 1 << RS_TIMER;
#endif

	/*
	 * Set up the tty->alt_speed kludge
	 */
	if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
		tty->alt_speed = 57600;
	if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
		tty->alt_speed = 115200;
	if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
		tty->alt_speed = 230400;
	if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
		tty->alt_speed = 460800;

	state->flags |= ASYNC_INITIALIZED;
	local_irq_restore(flags);
	return 0;

errout:
	local_irq_restore(flags);
	return retval;
}


/*
 * This routine is called whenever a serial port is opened.  It
 * enables interrupts for a serial port, linking in its async structure into
 * the IRQ chain.   It also performs the serial-specific
 * initialization for the tty structure.
 */
static int rs_open(struct tty_struct *tty, struct file * filp)
{
	struct serial_state *info = rs_table + tty->index;
	int			retval;
	unsigned long		page;

	info->count++;
	info->tport.tty = tty;
	tty->driver_data = info;
	tty->port = &info->tport;

#ifdef SIMSERIAL_DEBUG
	printk("rs_open %s, count = %d\n", tty->name, info->count);
#endif
	tty->low_latency = (info->flags & ASYNC_LOW_LATENCY) ? 1 : 0;

	if (!tmp_buf) {
		page = get_zeroed_page(GFP_KERNEL);
		if (!page)
			return -ENOMEM;
		if (tmp_buf)
			free_page(page);
		else
			tmp_buf = (unsigned char *) page;
	}

	/*
	 * If the port is the middle of closing, bail out now
	 */
	if (tty_hung_up_p(filp) || (info->flags & ASYNC_CLOSING)) {
		if (info->flags & ASYNC_CLOSING)
			interruptible_sleep_on(&info->tport.close_wait);
#ifdef SERIAL_DO_RESTART
		return ((info->flags & ASYNC_HUP_NOTIFY) ?
			-EAGAIN : -ERESTARTSYS);
#else
		return -EAGAIN;
#endif
	}

	/*
	 * Start up serial port
	 */
	retval = startup(tty, info);
	if (retval) {
		return retval;
	}

	/*
	 * figure out which console to use (should be one already)
	 */
	console = console_drivers;
	while (console) {
		if ((console->flags & CON_ENABLED) && console->write) break;
		console = console->next;
	}

#ifdef SIMSERIAL_DEBUG
	printk("rs_open ttys%d successful\n", info->line);
#endif
	return 0;
}

/*
 * /proc fs routines....
 */

static inline void line_info(struct seq_file *m, struct serial_state *state)
{
	seq_printf(m, "%d: uart:%s port:%lX irq:%d\n",
		       state->line, uart_config[state->type].name,
		       state->port, state->irq);
}

static int rs_proc_show(struct seq_file *m, void *v)
{
	int i;

	seq_printf(m, "simserinfo:1.0 driver:%s\n", serial_version);
	for (i = 0; i < NR_PORTS; i++)
		line_info(m, &rs_table[i]);
	return 0;
}

static int rs_proc_open(struct inode *inode, struct file *file)
{
	return single_open(file, rs_proc_show, NULL);
}

static const struct file_operations rs_proc_fops = {
	.owner		= THIS_MODULE,
	.open		= rs_proc_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

/*
 * ---------------------------------------------------------------------
 * rs_init() and friends
 *
 * rs_init() is called at boot-time to initialize the serial driver.
 * ---------------------------------------------------------------------
 */

/*
 * This routine prints out the appropriate serial driver version
 * number, and identifies which options were configured into this
 * driver.
 */
static inline void show_serial_version(void)
{
	printk(KERN_INFO "%s version %s with", serial_name, serial_version);
	printk(KERN_INFO " no serial options enabled\n");
}

static const struct tty_operations hp_ops = {
	.open = rs_open,
	.close = rs_close,
	.write = rs_write,
	.put_char = rs_put_char,
	.flush_chars = rs_flush_chars,
	.write_room = rs_write_room,
	.chars_in_buffer = rs_chars_in_buffer,
	.flush_buffer = rs_flush_buffer,
	.ioctl = rs_ioctl,
	.throttle = rs_throttle,
	.unthrottle = rs_unthrottle,
	.send_xchar = rs_send_xchar,
	.set_termios = rs_set_termios,
	.stop = rs_stop,
	.start = rs_start,
	.hangup = rs_hangup,
	.wait_until_sent = rs_wait_until_sent,
	.proc_fops = &rs_proc_fops,
};

/*
 * The serial driver boot-time initialization code!
 */
static int __init
simrs_init (void)
{
	int			i, rc;
	struct serial_state	*state;

	if (!ia64_platform_is("hpsim"))
		return -ENODEV;

	hp_simserial_driver = alloc_tty_driver(NR_PORTS);
	if (!hp_simserial_driver)
		return -ENOMEM;

	show_serial_version();

	/* Initialize the tty_driver structure */

	hp_simserial_driver->driver_name = "simserial";
	hp_simserial_driver->name = "ttyS";
	hp_simserial_driver->major = TTY_MAJOR;
	hp_simserial_driver->minor_start = 64;
	hp_simserial_driver->type = TTY_DRIVER_TYPE_SERIAL;
	hp_simserial_driver->subtype = SERIAL_TYPE_NORMAL;
	hp_simserial_driver->init_termios = tty_std_termios;
	hp_simserial_driver->init_termios.c_cflag =
		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
	hp_simserial_driver->flags = TTY_DRIVER_REAL_RAW;
	tty_set_operations(hp_simserial_driver, &hp_ops);

	/*
	 * Let's have a little bit of fun !
	 */
	for (i = 0, state = rs_table; i < NR_PORTS; i++,state++) {
		tty_port_init(&state->tport);
		state->tport.close_delay = 0; /* XXX really 0? */

		if (state->type == PORT_UNKNOWN) continue;

		if (!state->irq) {
			if ((rc = hpsim_get_irq(KEYBOARD_INTR)) < 0)
				panic("%s: out of interrupt vectors!\n",
				      __func__);
			state->irq = rc;
		}

		printk(KERN_INFO "ttyS%d at 0x%04lx (irq = %d) is a %s\n",
		       state->line,
		       state->port, state->irq,
		       uart_config[state->type].name);
	}

	if (tty_register_driver(hp_simserial_driver))
		panic("Couldn't register simserial driver\n");

	return 0;
}

#ifndef MODULE
__initcall(simrs_init);
#endif