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[PATCH] i386: clear segment register padding in core dumps
[linux-2.6/linux-loongson.git] / drivers / tc / zs.c
blob3d72aa5cfc713bb3b66dbe3c6b49ee8ceb25d0df
1 /*
2 * decserial.c: Serial port driver for IOASIC DECstations.
3 *
4 * Derived from drivers/sbus/char/sunserial.c by Paul Mackerras.
5 * Derived from drivers/macintosh/macserial.c by Harald Koerfgen.
6 *
7 * DECstation changes
8 * Copyright (C) 1998-2000 Harald Koerfgen
9 * Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005 Maciej W. Rozycki
10 *
11 * For the rest of the code the original Copyright applies:
12 * Copyright (C) 1996 Paul Mackerras (Paul.Mackerras@cs.anu.edu.au)
13 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
14 *
15 *
16 * Note: for IOASIC systems the wiring is as follows:
17 *
18 * mouse/keyboard:
19 * DIN-7 MJ-4 signal SCC
20 * 2 1 TxD <- A.TxD
21 * 3 4 RxD -> A.RxD
22 *
23 * EIA-232/EIA-423:
24 * DB-25 MMJ-6 signal SCC
25 * 2 2 TxD <- B.TxD
26 * 3 5 RxD -> B.RxD
27 * 4 RTS <- ~A.RTS
28 * 5 CTS -> ~B.CTS
29 * 6 6 DSR -> ~A.SYNC
30 * 8 CD -> ~B.DCD
31 * 12 DSRS(DCE) -> ~A.CTS (*)
32 * 15 TxC -> B.TxC
33 * 17 RxC -> B.RxC
34 * 20 1 DTR <- ~A.DTR
35 * 22 RI -> ~A.DCD
36 * 23 DSRS(DTE) <- ~B.RTS
37 *
38 * (*) EIA-232 defines the signal at this pin to be SCD, while DSRS(DCE)
39 * is shared with DSRS(DTE) at pin 23.
40 */
41
42 #include <linux/errno.h>
43 #include <linux/signal.h>
44 #include <linux/sched.h>
45 #include <linux/timer.h>
46 #include <linux/interrupt.h>
47 #include <linux/tty.h>
48 #include <linux/tty_flip.h>
49 #include <linux/major.h>
50 #include <linux/string.h>
51 #include <linux/fcntl.h>
52 #include <linux/mm.h>
53 #include <linux/kernel.h>
54 #include <linux/delay.h>
55 #include <linux/init.h>
56 #include <linux/ioport.h>
57 #include <linux/spinlock.h>
58 #ifdef CONFIG_SERIAL_DEC_CONSOLE
59 #include <linux/console.h>
60 #endif
61
62 #include <asm/io.h>
63 #include <asm/pgtable.h>
64 #include <asm/irq.h>
65 #include <asm/system.h>
66 #include <asm/bootinfo.h>
67
68 #include <asm/dec/interrupts.h>
69 #include <asm/dec/ioasic_addrs.h>
70 #include <asm/dec/machtype.h>
71 #include <asm/dec/serial.h>
72 #include <asm/dec/system.h>
73 #include <asm/dec/tc.h>
74
75 #ifdef CONFIG_KGDB
76 #include <asm/kgdb.h>
77 #endif
78 #ifdef CONFIG_MAGIC_SYSRQ
79 #include <linux/sysrq.h>
80 #endif
81
82 #include "zs.h"
83
84 /*
85 * It would be nice to dynamically allocate everything that
86 * depends on NUM_SERIAL, so we could support any number of
87 * Z8530s, but for now...
88 */
89 #define NUM_SERIAL 2 /* Max number of ZS chips supported */
90 #define NUM_CHANNELS (NUM_SERIAL * 2) /* 2 channels per chip */
91 #define CHANNEL_A_NR (zs_parms->channel_a_offset > zs_parms->channel_b_offset)
92 /* Number of channel A in the chip */
93 #define ZS_CHAN_IO_SIZE 8
94 #define ZS_CLOCK 7372800 /* Z8530 RTxC input clock rate */
95
96 #define RECOVERY_DELAY udelay(2)
97
98 struct zs_parms {
99 unsigned long scc0;
100 unsigned long scc1;
101 int channel_a_offset;
102 int channel_b_offset;
103 int irq0;
104 int irq1;
105 int clock;
106 };
107
108 static struct zs_parms *zs_parms;
109
110 #ifdef CONFIG_MACH_DECSTATION
111 static struct zs_parms ds_parms = {
112 scc0 : IOASIC_SCC0,
113 scc1 : IOASIC_SCC1,
114 channel_a_offset : 1,
115 channel_b_offset : 9,
116 irq0 : -1,
117 irq1 : -1,
118 clock : ZS_CLOCK
119 };
120 #endif
121
122 #ifdef CONFIG_MACH_DECSTATION
123 #define DS_BUS_PRESENT (IOASIC)
124 #else
125 #define DS_BUS_PRESENT 0
126 #endif
127
128 #define BUS_PRESENT (DS_BUS_PRESENT)
129
130 DEFINE_SPINLOCK(zs_lock);
131
132 struct dec_zschannel zs_channels[NUM_CHANNELS];
133 struct dec_serial zs_soft[NUM_CHANNELS];
134 int zs_channels_found;
135 struct dec_serial *zs_chain; /* list of all channels */
136
137 struct tty_struct zs_ttys[NUM_CHANNELS];
138
139 #ifdef CONFIG_SERIAL_DEC_CONSOLE
140 static struct console sercons;
141 #endif
142 #if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \
143 !defined(MODULE)
144 static unsigned long break_pressed; /* break, really ... */
145 #endif
146
147 static unsigned char zs_init_regs[16] __initdata = {
148 0, /* write 0 */
149 0, /* write 1 */
150 0, /* write 2 */
151 0, /* write 3 */
152 (X16CLK), /* write 4 */
153 0, /* write 5 */
154 0, 0, 0, /* write 6, 7, 8 */
155 (MIE | DLC | NV), /* write 9 */
156 (NRZ), /* write 10 */
157 (TCBR | RCBR), /* write 11 */
158 0, 0, /* BRG time constant, write 12 + 13 */
159 (BRSRC | BRENABL), /* write 14 */
160 0 /* write 15 */
161 };
162
163 static struct tty_driver *serial_driver;
164
165 /* serial subtype definitions */
166 #define SERIAL_TYPE_NORMAL 1
167
168 /* number of characters left in xmit buffer before we ask for more */
169 #define WAKEUP_CHARS 256
170
171 /*
172 * Debugging.
173 */
174 #undef SERIAL_DEBUG_OPEN
175 #undef SERIAL_DEBUG_FLOW
176 #undef SERIAL_DEBUG_THROTTLE
177 #undef SERIAL_PARANOIA_CHECK
178
179 #undef ZS_DEBUG_REGS
180
181 #ifdef SERIAL_DEBUG_THROTTLE
182 #define _tty_name(tty,buf) tty_name(tty,buf)
183 #endif
184
185 #define RS_STROBE_TIME 10
186 #define RS_ISR_PASS_LIMIT 256
187
188 static void probe_sccs(void);
189 static void change_speed(struct dec_serial *info);
190 static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
191
192 static inline int serial_paranoia_check(struct dec_serial *info,
193 char *name, const char *routine)
194 {
195 #ifdef SERIAL_PARANOIA_CHECK
196 static const char *badmagic =
197 "Warning: bad magic number for serial struct %s in %s\n";
198 static const char *badinfo =
199 "Warning: null mac_serial for %s in %s\n";
200
201 if (!info) {
202 printk(badinfo, name, routine);
203 return 1;
204 }
205 if (info->magic != SERIAL_MAGIC) {
206 printk(badmagic, name, routine);
207 return 1;
208 }
209 #endif
210 return 0;
211 }
212
213 /*
214 * This is used to figure out the divisor speeds and the timeouts
215 */
216 static int baud_table[] = {
217 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
218 9600, 19200, 38400, 57600, 115200, 0 };
219
220 /*
221 * Reading and writing Z8530 registers.
222 */
223 static inline unsigned char read_zsreg(struct dec_zschannel *channel,
224 unsigned char reg)
225 {
226 unsigned char retval;
227
228 if (reg != 0) {
229 *channel->control = reg & 0xf;
230 fast_iob(); RECOVERY_DELAY;
231 }
232 retval = *channel->control;
233 RECOVERY_DELAY;
234 return retval;
235 }
236
237 static inline void write_zsreg(struct dec_zschannel *channel,
238 unsigned char reg, unsigned char value)
239 {
240 if (reg != 0) {
241 *channel->control = reg & 0xf;
242 fast_iob(); RECOVERY_DELAY;
243 }
244 *channel->control = value;
245 fast_iob(); RECOVERY_DELAY;
246 return;
247 }
248
249 static inline unsigned char read_zsdata(struct dec_zschannel *channel)
250 {
251 unsigned char retval;
252
253 retval = *channel->data;
254 RECOVERY_DELAY;
255 return retval;
256 }
257
258 static inline void write_zsdata(struct dec_zschannel *channel,
259 unsigned char value)
260 {
261 *channel->data = value;
262 fast_iob(); RECOVERY_DELAY;
263 return;
264 }
265
266 static inline void load_zsregs(struct dec_zschannel *channel,
267 unsigned char *regs)
268 {
269 /* ZS_CLEARERR(channel);
270 ZS_CLEARFIFO(channel); */
271 /* Load 'em up */
272 write_zsreg(channel, R3, regs[R3] & ~RxENABLE);
273 write_zsreg(channel, R5, regs[R5] & ~TxENAB);
274 write_zsreg(channel, R4, regs[R4]);
275 write_zsreg(channel, R9, regs[R9]);
276 write_zsreg(channel, R1, regs[R1]);
277 write_zsreg(channel, R2, regs[R2]);
278 write_zsreg(channel, R10, regs[R10]);
279 write_zsreg(channel, R11, regs[R11]);
280 write_zsreg(channel, R12, regs[R12]);
281 write_zsreg(channel, R13, regs[R13]);
282 write_zsreg(channel, R14, regs[R14]);
283 write_zsreg(channel, R15, regs[R15]);
284 write_zsreg(channel, R3, regs[R3]);
285 write_zsreg(channel, R5, regs[R5]);
286 return;
287 }
288
289 /* Sets or clears DTR/RTS on the requested line */
290 static inline void zs_rtsdtr(struct dec_serial *info, int which, int set)
291 {
292 unsigned long flags;
293
294 spin_lock_irqsave(&zs_lock, flags);
295 if (info->zs_channel != info->zs_chan_a) {
296 if (set) {
297 info->zs_chan_a->curregs[5] |= (which & (RTS | DTR));
298 } else {
299 info->zs_chan_a->curregs[5] &= ~(which & (RTS | DTR));
300 }
301 write_zsreg(info->zs_chan_a, 5, info->zs_chan_a->curregs[5]);
302 }
303 spin_unlock_irqrestore(&zs_lock, flags);
304 }
305
306 /* Utility routines for the Zilog */
307 static inline int get_zsbaud(struct dec_serial *ss)
308 {
309 struct dec_zschannel *channel = ss->zs_channel;
310 int brg;
311
312 /* The baud rate is split up between two 8-bit registers in
313 * what is termed 'BRG time constant' format in my docs for
314 * the chip, it is a function of the clk rate the chip is
315 * receiving which happens to be constant.
316 */
317 brg = (read_zsreg(channel, 13) << 8);
318 brg |= read_zsreg(channel, 12);
319 return BRG_TO_BPS(brg, (zs_parms->clock/(ss->clk_divisor)));
320 }
321
322 /* On receive, this clears errors and the receiver interrupts */
323 static inline void rs_recv_clear(struct dec_zschannel *zsc)
324 {
325 write_zsreg(zsc, 0, ERR_RES);
326 write_zsreg(zsc, 0, RES_H_IUS); /* XXX this is unnecessary */
327 }
328
329 /*
330 * ----------------------------------------------------------------------
331 *
332 * Here starts the interrupt handling routines. All of the following
333 * subroutines are declared as inline and are folded into
334 * rs_interrupt(). They were separated out for readability's sake.
335 *
336 * - Ted Ts'o (tytso@mit.edu), 7-Mar-93
337 * -----------------------------------------------------------------------
338 */
339
340 /*
341 * This routine is used by the interrupt handler to schedule
342 * processing in the software interrupt portion of the driver.
343 */
344 static void rs_sched_event(struct dec_serial *info, int event)
345 {
346 info->event |= 1 << event;
347 tasklet_schedule(&info->tlet);
348 }
349
350 static void receive_chars(struct dec_serial *info)
351 {
352 struct tty_struct *tty = info->tty;
353 unsigned char ch, stat, flag;
354
355 while ((read_zsreg(info->zs_channel, R0) & Rx_CH_AV) != 0) {
356
357 stat = read_zsreg(info->zs_channel, R1);
358 ch = read_zsdata(info->zs_channel);
359
360 if (!tty && (!info->hook || !info->hook->rx_char))
361 continue;
362
363 flag = TTY_NORMAL;
364 if (info->tty_break) {
365 info->tty_break = 0;
366 flag = TTY_BREAK;
367 if (info->flags & ZILOG_SAK)
368 do_SAK(tty);
369 /* Ignore the null char got when BREAK is removed. */
370 if (ch == 0)
371 continue;
372 } else {
373 if (stat & Rx_OVR) {
374 flag = TTY_OVERRUN;
375 } else if (stat & FRM_ERR) {
376 flag = TTY_FRAME;
377 } else if (stat & PAR_ERR) {
378 flag = TTY_PARITY;
379 }
380 if (flag != TTY_NORMAL)
381 /* reset the error indication */
382 write_zsreg(info->zs_channel, R0, ERR_RES);
383 }
384
385 #if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \
386 !defined(MODULE)
387 if (break_pressed && info->line == sercons.index) {
388 /* Ignore the null char got when BREAK is removed. */
389 if (ch == 0)
390 continue;
391 if (time_before(jiffies, break_pressed + HZ * 5)) {
392 handle_sysrq(ch, NULL);
393 break_pressed = 0;
394 continue;
395 }
396 break_pressed = 0;
397 }
398 #endif
399
400 if (info->hook && info->hook->rx_char) {
401 (*info->hook->rx_char)(ch, flag);
402 return;
403 }
404
405 tty_insert_flip_char(tty, ch, flag);
406 }
407 if (tty)
408 tty_flip_buffer_push(tty);
409 }
410
411 static void transmit_chars(struct dec_serial *info)
412 {
413 if ((read_zsreg(info->zs_channel, R0) & Tx_BUF_EMP) == 0)
414 return;
415 info->tx_active = 0;
416
417 if (info->x_char) {
418 /* Send next char */
419 write_zsdata(info->zs_channel, info->x_char);
420 info->x_char = 0;
421 info->tx_active = 1;
422 return;
423 }
424
425 if ((info->xmit_cnt <= 0) || (info->tty && info->tty->stopped)
426 || info->tx_stopped) {
427 write_zsreg(info->zs_channel, R0, RES_Tx_P);
428 return;
429 }
430 /* Send char */
431 write_zsdata(info->zs_channel, info->xmit_buf[info->xmit_tail++]);
432 info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
433 info->xmit_cnt--;
434 info->tx_active = 1;
435
436 if (info->xmit_cnt < WAKEUP_CHARS)
437 rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
438 }
439
440 static void status_handle(struct dec_serial *info)
441 {
442 unsigned char stat;
443
444 /* Get status from Read Register 0 */
445 stat = read_zsreg(info->zs_channel, R0);
446
447 if ((stat & BRK_ABRT) && !(info->read_reg_zero & BRK_ABRT)) {
448 #if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \
449 !defined(MODULE)
450 if (info->line == sercons.index) {
451 if (!break_pressed)
452 break_pressed = jiffies;
453 } else
454 #endif
455 info->tty_break = 1;
456 }
457
458 if (info->zs_channel != info->zs_chan_a) {
459
460 /* Check for DCD transitions */
461 if (info->tty && !C_CLOCAL(info->tty) &&
462 ((stat ^ info->read_reg_zero) & DCD) != 0 ) {
463 if (stat & DCD) {
464 wake_up_interruptible(&info->open_wait);
465 } else {
466 tty_hangup(info->tty);
467 }
468 }
469
470 /* Check for CTS transitions */
471 if (info->tty && C_CRTSCTS(info->tty)) {
472 if ((stat & CTS) != 0) {
473 if (info->tx_stopped) {
474 info->tx_stopped = 0;
475 if (!info->tx_active)
476 transmit_chars(info);
477 }
478 } else {
479 info->tx_stopped = 1;
480 }
481 }
482
483 }
484
485 /* Clear status condition... */
486 write_zsreg(info->zs_channel, R0, RES_EXT_INT);
487 info->read_reg_zero = stat;
488 }
489
490 /*
491 * This is the serial driver's generic interrupt routine
492 */
493 static irqreturn_t rs_interrupt(int irq, void *dev_id)
494 {
495 struct dec_serial *info = (struct dec_serial *) dev_id;
496 irqreturn_t status = IRQ_NONE;
497 unsigned char zs_intreg;
498 int shift;
499
500 /* NOTE: The read register 3, which holds the irq status,
501 * does so for both channels on each chip. Although
502 * the status value itself must be read from the A
503 * channel and is only valid when read from channel A.
504 * Yes... broken hardware...
505 */
506 #define CHAN_IRQMASK (CHBRxIP | CHBTxIP | CHBEXT)
507
508 if (info->zs_chan_a == info->zs_channel)
509 shift = 3; /* Channel A */
510 else
511 shift = 0; /* Channel B */
512
513 for (;;) {
514 zs_intreg = read_zsreg(info->zs_chan_a, R3) >> shift;
515 if ((zs_intreg & CHAN_IRQMASK) == 0)
516 break;
517
518 status = IRQ_HANDLED;
519
520 if (zs_intreg & CHBRxIP) {
521 receive_chars(info);
522 }
523 if (zs_intreg & CHBTxIP) {
524 transmit_chars(info);
525 }
526 if (zs_intreg & CHBEXT) {
527 status_handle(info);
528 }
529 }
530
531 /* Why do we need this ? */
532 write_zsreg(info->zs_channel, 0, RES_H_IUS);
533
534 return status;
535 }
536
537 #ifdef ZS_DEBUG_REGS
538 void zs_dump (void) {
539 int i, j;
540 for (i = 0; i < zs_channels_found; i++) {
541 struct dec_zschannel *ch = &zs_channels[i];
542 if ((long)ch->control == UNI_IO_BASE+UNI_SCC1A_CTRL) {
543 for (j = 0; j < 15; j++) {
544 printk("W%d = 0x%x\t",
545 j, (int)ch->curregs[j]);
546 }
547 for (j = 0; j < 15; j++) {
548 printk("R%d = 0x%x\t",
549 j, (int)read_zsreg(ch,j));
550 }
551 printk("\n\n");
552 }
553 }
554 }
555 #endif
556
557 /*
558 * -------------------------------------------------------------------
559 * Here ends the serial interrupt routines.
560 * -------------------------------------------------------------------
561 */
562
563 /*
564 * ------------------------------------------------------------
565 * rs_stop() and rs_start()
566 *
567 * This routines are called before setting or resetting tty->stopped.
568 * ------------------------------------------------------------
569 */
570 static void rs_stop(struct tty_struct *tty)
571 {
572 struct dec_serial *info = (struct dec_serial *)tty->driver_data;
573 unsigned long flags;
574
575 if (serial_paranoia_check(info, tty->name, "rs_stop"))
576 return;
577
578 #if 1
579 spin_lock_irqsave(&zs_lock, flags);
580 if (info->zs_channel->curregs[5] & TxENAB) {
581 info->zs_channel->curregs[5] &= ~TxENAB;
582 write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
583 }
584 spin_unlock_irqrestore(&zs_lock, flags);
585 #endif
586 }
587
588 static void rs_start(struct tty_struct *tty)
589 {
590 struct dec_serial *info = (struct dec_serial *)tty->driver_data;
591 unsigned long flags;
592
593 if (serial_paranoia_check(info, tty->name, "rs_start"))
594 return;
595
596 spin_lock_irqsave(&zs_lock, flags);
597 #if 1
598 if (info->xmit_cnt && info->xmit_buf && !(info->zs_channel->curregs[5] & TxENAB)) {
599 info->zs_channel->curregs[5] |= TxENAB;
600 write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
601 }
602 #else
603 if (info->xmit_cnt && info->xmit_buf && !info->tx_active) {
604 transmit_chars(info);
605 }
606 #endif
607 spin_unlock_irqrestore(&zs_lock, flags);
608 }
609
610 /*
611 * This routine is used to handle the "bottom half" processing for the
612 * serial driver, known also the "software interrupt" processing.
613 * This processing is done at the kernel interrupt level, after the
614 * rs_interrupt() has returned, BUT WITH INTERRUPTS TURNED ON. This
615 * is where time-consuming activities which can not be done in the
616 * interrupt driver proper are done; the interrupt driver schedules
617 * them using rs_sched_event(), and they get done here.
618 */
619
620 static void do_softint(unsigned long private_)
621 {
622 struct dec_serial *info = (struct dec_serial *) private_;
623 struct tty_struct *tty;
624
625 tty = info->tty;
626 if (!tty)
627 return;
628
629 if (test_and_clear_bit(RS_EVENT_WRITE_WAKEUP, &info->event))
630 tty_wakeup(tty);
631 }
632
633 static int zs_startup(struct dec_serial * info)
634 {
635 unsigned long flags;
636
637 if (info->flags & ZILOG_INITIALIZED)
638 return 0;
639
640 if (!info->xmit_buf) {
641 info->xmit_buf = (unsigned char *) get_zeroed_page(GFP_KERNEL);
642 if (!info->xmit_buf)
643 return -ENOMEM;
644 }
645
646 spin_lock_irqsave(&zs_lock, flags);
647
648 #ifdef SERIAL_DEBUG_OPEN
649 printk("starting up ttyS%d (irq %d)...", info->line, info->irq);
650 #endif
651
652 /*
653 * Clear the receive FIFO.
654 */
655 ZS_CLEARFIFO(info->zs_channel);
656 info->xmit_fifo_size = 1;
657
658 /*
659 * Clear the interrupt registers.
660 */
661 write_zsreg(info->zs_channel, R0, ERR_RES);
662 write_zsreg(info->zs_channel, R0, RES_H_IUS);
663
664 /*
665 * Set the speed of the serial port
666 */
667 change_speed(info);
668
669 /*
670 * Turn on RTS and DTR.
671 */
672 zs_rtsdtr(info, RTS | DTR, 1);
673
674 /*
675 * Finally, enable sequencing and interrupts
676 */
677 info->zs_channel->curregs[R1] &= ~RxINT_MASK;
678 info->zs_channel->curregs[R1] |= (RxINT_ALL | TxINT_ENAB |
679 EXT_INT_ENAB);
680 info->zs_channel->curregs[R3] |= RxENABLE;
681 info->zs_channel->curregs[R5] |= TxENAB;
682 info->zs_channel->curregs[R15] |= (DCDIE | CTSIE | TxUIE | BRKIE);
683 write_zsreg(info->zs_channel, R1, info->zs_channel->curregs[R1]);
684 write_zsreg(info->zs_channel, R3, info->zs_channel->curregs[R3]);
685 write_zsreg(info->zs_channel, R5, info->zs_channel->curregs[R5]);
686 write_zsreg(info->zs_channel, R15, info->zs_channel->curregs[R15]);
687
688 /*
689 * And clear the interrupt registers again for luck.
690 */
691 write_zsreg(info->zs_channel, R0, ERR_RES);
692 write_zsreg(info->zs_channel, R0, RES_H_IUS);
693
694 /* Save the current value of RR0 */
695 info->read_reg_zero = read_zsreg(info->zs_channel, R0);
696
697 if (info->tty)
698 clear_bit(TTY_IO_ERROR, &info->tty->flags);
699 info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
700
701 info->flags |= ZILOG_INITIALIZED;
702 spin_unlock_irqrestore(&zs_lock, flags);
703 return 0;
704 }
705
706 /*
707 * This routine will shutdown a serial port; interrupts are disabled, and
708 * DTR is dropped if the hangup on close termio flag is on.
709 */
710 static void shutdown(struct dec_serial * info)
711 {
712 unsigned long flags;
713
714 if (!(info->flags & ZILOG_INITIALIZED))
715 return;
716
717 #ifdef SERIAL_DEBUG_OPEN
718 printk("Shutting down serial port %d (irq %d)....", info->line,
719 info->irq);
720 #endif
721
722 spin_lock_irqsave(&zs_lock, flags);
723
724 if (info->xmit_buf) {
725 free_page((unsigned long) info->xmit_buf);
726 info->xmit_buf = 0;
727 }
728
729 info->zs_channel->curregs[1] = 0;
730 write_zsreg(info->zs_channel, 1, info->zs_channel->curregs[1]); /* no interrupts */
731
732 info->zs_channel->curregs[3] &= ~RxENABLE;
733 write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
734
735 info->zs_channel->curregs[5] &= ~TxENAB;
736 write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
737 if (!info->tty || C_HUPCL(info->tty)) {
738 zs_rtsdtr(info, RTS | DTR, 0);
739 }
740
741 if (info->tty)
742 set_bit(TTY_IO_ERROR, &info->tty->flags);
743
744 info->flags &= ~ZILOG_INITIALIZED;
745 spin_unlock_irqrestore(&zs_lock, flags);
746 }
747
748 /*
749 * This routine is called to set the UART divisor registers to match
750 * the specified baud rate for a serial port.
751 */
752 static void change_speed(struct dec_serial *info)
753 {
754 unsigned cflag;
755 int i;
756 int brg, bits;
757 unsigned long flags;
758
759 if (!info->hook) {
760 if (!info->tty || !info->tty->termios)
761 return;
762 cflag = info->tty->termios->c_cflag;
763 if (!info->port)
764 return;
765 } else {
766 cflag = info->hook->cflags;
767 }
768
769 i = cflag & CBAUD;
770 if (i & CBAUDEX) {
771 i &= ~CBAUDEX;
772 if (i < 1 || i > 2) {
773 if (!info->hook)
774 info->tty->termios->c_cflag &= ~CBAUDEX;
775 else
776 info->hook->cflags &= ~CBAUDEX;
777 } else
778 i += 15;
779 }
780
781 spin_lock_irqsave(&zs_lock, flags);
782 info->zs_baud = baud_table[i];
783 if (info->zs_baud) {
784 brg = BPS_TO_BRG(info->zs_baud, zs_parms->clock/info->clk_divisor);
785 info->zs_channel->curregs[12] = (brg & 255);
786 info->zs_channel->curregs[13] = ((brg >> 8) & 255);
787 zs_rtsdtr(info, DTR, 1);
788 } else {
789 zs_rtsdtr(info, RTS | DTR, 0);
790 return;
791 }
792
793 /* byte size and parity */
794 info->zs_channel->curregs[3] &= ~RxNBITS_MASK;
795 info->zs_channel->curregs[5] &= ~TxNBITS_MASK;
796 switch (cflag & CSIZE) {
797 case CS5:
798 bits = 7;
799 info->zs_channel->curregs[3] |= Rx5;
800 info->zs_channel->curregs[5] |= Tx5;
801 break;
802 case CS6:
803 bits = 8;
804 info->zs_channel->curregs[3] |= Rx6;
805 info->zs_channel->curregs[5] |= Tx6;
806 break;
807 case CS7:
808 bits = 9;
809 info->zs_channel->curregs[3] |= Rx7;
810 info->zs_channel->curregs[5] |= Tx7;
811 break;
812 case CS8:
813 default: /* defaults to 8 bits */
814 bits = 10;
815 info->zs_channel->curregs[3] |= Rx8;
816 info->zs_channel->curregs[5] |= Tx8;
817 break;
818 }
819
820 info->timeout = ((info->xmit_fifo_size*HZ*bits) / info->zs_baud);
821 info->timeout += HZ/50; /* Add .02 seconds of slop */
822
823 info->zs_channel->curregs[4] &= ~(SB_MASK | PAR_ENA | PAR_EVEN);
824 if (cflag & CSTOPB) {
825 info->zs_channel->curregs[4] |= SB2;
826 } else {
827 info->zs_channel->curregs[4] |= SB1;
828 }
829 if (cflag & PARENB) {
830 info->zs_channel->curregs[4] |= PAR_ENA;
831 }
832 if (!(cflag & PARODD)) {
833 info->zs_channel->curregs[4] |= PAR_EVEN;
834 }
835
836 if (!(cflag & CLOCAL)) {
837 if (!(info->zs_channel->curregs[15] & DCDIE))
838 info->read_reg_zero = read_zsreg(info->zs_channel, 0);
839 info->zs_channel->curregs[15] |= DCDIE;
840 } else
841 info->zs_channel->curregs[15] &= ~DCDIE;
842 if (cflag & CRTSCTS) {
843 info->zs_channel->curregs[15] |= CTSIE;
844 if ((read_zsreg(info->zs_channel, 0) & CTS) == 0)
845 info->tx_stopped = 1;
846 } else {
847 info->zs_channel->curregs[15] &= ~CTSIE;
848 info->tx_stopped = 0;
849 }
850
851 /* Load up the new values */
852 load_zsregs(info->zs_channel, info->zs_channel->curregs);
853
854 spin_unlock_irqrestore(&zs_lock, flags);
855 }
856
857 static void rs_flush_chars(struct tty_struct *tty)
858 {
859 struct dec_serial *info = (struct dec_serial *)tty->driver_data;
860 unsigned long flags;
861
862 if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
863 return;
864
865 if (info->xmit_cnt <= 0 || tty->stopped || info->tx_stopped ||
866 !info->xmit_buf)
867 return;
868
869 /* Enable transmitter */
870 spin_lock_irqsave(&zs_lock, flags);
871 transmit_chars(info);
872 spin_unlock_irqrestore(&zs_lock, flags);
873 }
874
875 static int rs_write(struct tty_struct * tty,
876 const unsigned char *buf, int count)
877 {
878 int c, total = 0;
879 struct dec_serial *info = (struct dec_serial *)tty->driver_data;
880 unsigned long flags;
881
882 if (serial_paranoia_check(info, tty->name, "rs_write"))
883 return 0;
884
885 if (!tty || !info->xmit_buf)
886 return 0;
887
888 while (1) {
889 spin_lock_irqsave(&zs_lock, flags);
890 c = min(count, min(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
891 SERIAL_XMIT_SIZE - info->xmit_head));
892 if (c <= 0)
893 break;
894
895 memcpy(info->xmit_buf + info->xmit_head, buf, c);
896 info->xmit_head = (info->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
897 info->xmit_cnt += c;
898 spin_unlock_irqrestore(&zs_lock, flags);
899 buf += c;
900 count -= c;
901 total += c;
902 }
903
904 if (info->xmit_cnt && !tty->stopped && !info->tx_stopped
905 && !info->tx_active)
906 transmit_chars(info);
907 spin_unlock_irqrestore(&zs_lock, flags);
908 return total;
909 }
910
911 static int rs_write_room(struct tty_struct *tty)
912 {
913 struct dec_serial *info = (struct dec_serial *)tty->driver_data;
914 int ret;
915
916 if (serial_paranoia_check(info, tty->name, "rs_write_room"))
917 return 0;
918 ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
919 if (ret < 0)
920 ret = 0;
921 return ret;
922 }
923
924 static int rs_chars_in_buffer(struct tty_struct *tty)
925 {
926 struct dec_serial *info = (struct dec_serial *)tty->driver_data;
927
928 if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
929 return 0;
930 return info->xmit_cnt;
931 }
932
933 static void rs_flush_buffer(struct tty_struct *tty)
934 {
935 struct dec_serial *info = (struct dec_serial *)tty->driver_data;
936
937 if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
938 return;
939 spin_lock_irq(&zs_lock);
940 info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
941 spin_unlock_irq(&zs_lock);
942 tty_wakeup(tty);
943 }
944
945 /*
946 * ------------------------------------------------------------
947 * rs_throttle()
948 *
949 * This routine is called by the upper-layer tty layer to signal that
950 * incoming characters should be throttled.
951 * ------------------------------------------------------------
952 */
953 static void rs_throttle(struct tty_struct * tty)
954 {
955 struct dec_serial *info = (struct dec_serial *)tty->driver_data;
956 unsigned long flags;
957
958 #ifdef SERIAL_DEBUG_THROTTLE
959 char buf[64];
960
961 printk("throttle %s: %d....\n", _tty_name(tty, buf),
962 tty->ldisc.chars_in_buffer(tty));
963 #endif
964
965 if (serial_paranoia_check(info, tty->name, "rs_throttle"))
966 return;
967
968 if (I_IXOFF(tty)) {
969 spin_lock_irqsave(&zs_lock, flags);
970 info->x_char = STOP_CHAR(tty);
971 if (!info->tx_active)
972 transmit_chars(info);
973 spin_unlock_irqrestore(&zs_lock, flags);
974 }
975
976 if (C_CRTSCTS(tty)) {
977 zs_rtsdtr(info, RTS, 0);
978 }
979 }
980
981 static void rs_unthrottle(struct tty_struct * tty)
982 {
983 struct dec_serial *info = (struct dec_serial *)tty->driver_data;
984 unsigned long flags;
985
986 #ifdef SERIAL_DEBUG_THROTTLE
987 char buf[64];
988
989 printk("unthrottle %s: %d....\n", _tty_name(tty, buf),
990 tty->ldisc.chars_in_buffer(tty));
991 #endif
992
993 if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
994 return;
995
996 if (I_IXOFF(tty)) {
997 spin_lock_irqsave(&zs_lock, flags);
998 if (info->x_char)
999 info->x_char = 0;
1000 else {
1001 info->x_char = START_CHAR(tty);
1002 if (!info->tx_active)
1003 transmit_chars(info);
1004 }
1005 spin_unlock_irqrestore(&zs_lock, flags);
1006 }
1007
1008 if (C_CRTSCTS(tty)) {
1009 zs_rtsdtr(info, RTS, 1);
1010 }
1011 }
1012
1013 /*
1014 * ------------------------------------------------------------
1015 * rs_ioctl() and friends
1016 * ------------------------------------------------------------
1017 */
1018
1019 static int get_serial_info(struct dec_serial * info,
1020 struct serial_struct * retinfo)
1021 {
1022 struct serial_struct tmp;
1023
1024 if (!retinfo)
1025 return -EFAULT;
1026 memset(&tmp, 0, sizeof(tmp));
1027 tmp.type = info->type;
1028 tmp.line = info->line;
1029 tmp.port = info->port;
1030 tmp.irq = info->irq;
1031 tmp.flags = info->flags;
1032 tmp.baud_base = info->baud_base;
1033 tmp.close_delay = info->close_delay;
1034 tmp.closing_wait = info->closing_wait;
1035 tmp.custom_divisor = info->custom_divisor;
1036 return copy_to_user(retinfo,&tmp,sizeof(*retinfo)) ? -EFAULT : 0;
1037 }
1038
1039 static int set_serial_info(struct dec_serial * info,
1040 struct serial_struct * new_info)
1041 {
1042 struct serial_struct new_serial;
1043 struct dec_serial old_info;
1044 int retval = 0;
1045
1046 if (!new_info)
1047 return -EFAULT;
1048 copy_from_user(&new_serial,new_info,sizeof(new_serial));
1049 old_info = *info;
1050
1051 if (!capable(CAP_SYS_ADMIN)) {
1052 if ((new_serial.baud_base != info->baud_base) ||
1053 (new_serial.type != info->type) ||
1054 (new_serial.close_delay != info->close_delay) ||
1055 ((new_serial.flags & ~ZILOG_USR_MASK) !=
1056 (info->flags & ~ZILOG_USR_MASK)))
1057 return -EPERM;
1058 info->flags = ((info->flags & ~ZILOG_USR_MASK) |
1059 (new_serial.flags & ZILOG_USR_MASK));
1060 info->custom_divisor = new_serial.custom_divisor;
1061 goto check_and_exit;
1062 }
1063
1064 if (info->count > 1)
1065 return -EBUSY;
1066
1067 /*
1068 * OK, past this point, all the error checking has been done.
1069 * At this point, we start making changes.....
1070 */
1071
1072 info->baud_base = new_serial.baud_base;
1073 info->flags = ((info->flags & ~ZILOG_FLAGS) |
1074 (new_serial.flags & ZILOG_FLAGS));
1075 info->type = new_serial.type;
1076 info->close_delay = new_serial.close_delay;
1077 info->closing_wait = new_serial.closing_wait;
1078
1079 check_and_exit:
1080 retval = zs_startup(info);
1081 return retval;
1082 }
1083
1084 /*
1085 * get_lsr_info - get line status register info
1086 *
1087 * Purpose: Let user call ioctl() to get info when the UART physically
1088 * is emptied. On bus types like RS485, the transmitter must
1089 * release the bus after transmitting. This must be done when
1090 * the transmit shift register is empty, not be done when the
1091 * transmit holding register is empty. This functionality
1092 * allows an RS485 driver to be written in user space.
1093 */
1094 static int get_lsr_info(struct dec_serial * info, unsigned int *value)
1095 {
1096 unsigned char status;
1097
1098 spin_lock(&zs_lock);
1099 status = read_zsreg(info->zs_channel, 0);
1100 spin_unlock_irq(&zs_lock);
1101 put_user(status,value);
1102 return 0;
1103 }
1104
1105 static int rs_tiocmget(struct tty_struct *tty, struct file *file)
1106 {
1107 struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1108 unsigned char control, status_a, status_b;
1109 unsigned int result;
1110
1111 if (info->hook)
1112 return -ENODEV;
1113
1114 if (serial_paranoia_check(info, tty->name, __FUNCTION__))
1115 return -ENODEV;
1116
1117 if (tty->flags & (1 << TTY_IO_ERROR))
1118 return -EIO;
1119
1120 if (info->zs_channel == info->zs_chan_a)
1121 result = 0;
1122 else {
1123 spin_lock(&zs_lock);
1124 control = info->zs_chan_a->curregs[5];
1125 status_a = read_zsreg(info->zs_chan_a, 0);
1126 status_b = read_zsreg(info->zs_channel, 0);
1127 spin_unlock_irq(&zs_lock);
1128 result = ((control & RTS) ? TIOCM_RTS: 0)
1129 | ((control & DTR) ? TIOCM_DTR: 0)
1130 | ((status_b & DCD) ? TIOCM_CAR: 0)
1131 | ((status_a & DCD) ? TIOCM_RNG: 0)
1132 | ((status_a & SYNC_HUNT) ? TIOCM_DSR: 0)
1133 | ((status_b & CTS) ? TIOCM_CTS: 0);
1134 }
1135 return result;
1136 }
1137
1138 static int rs_tiocmset(struct tty_struct *tty, struct file *file,
1139 unsigned int set, unsigned int clear)
1140 {
1141 struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1142
1143 if (info->hook)
1144 return -ENODEV;
1145
1146 if (serial_paranoia_check(info, tty->name, __FUNCTION__))
1147 return -ENODEV;
1148
1149 if (tty->flags & (1 << TTY_IO_ERROR))
1150 return -EIO;
1151
1152 if (info->zs_channel == info->zs_chan_a)
1153 return 0;
1154
1155 spin_lock(&zs_lock);
1156 if (set & TIOCM_RTS)
1157 info->zs_chan_a->curregs[5] |= RTS;
1158 if (set & TIOCM_DTR)
1159 info->zs_chan_a->curregs[5] |= DTR;
1160 if (clear & TIOCM_RTS)
1161 info->zs_chan_a->curregs[5] &= ~RTS;
1162 if (clear & TIOCM_DTR)
1163 info->zs_chan_a->curregs[5] &= ~DTR;
1164 write_zsreg(info->zs_chan_a, 5, info->zs_chan_a->curregs[5]);
1165 spin_unlock_irq(&zs_lock);
1166 return 0;
1167 }
1168
1169 /*
1170 * rs_break - turn transmit break condition on/off
1171 */
1172 static void rs_break(struct tty_struct *tty, int break_state)
1173 {
1174 struct dec_serial *info = (struct dec_serial *) tty->driver_data;
1175 unsigned long flags;
1176
1177 if (serial_paranoia_check(info, tty->name, "rs_break"))
1178 return;
1179 if (!info->port)
1180 return;
1181
1182 spin_lock_irqsave(&zs_lock, flags);
1183 if (break_state == -1)
1184 info->zs_channel->curregs[5] |= SND_BRK;
1185 else
1186 info->zs_channel->curregs[5] &= ~SND_BRK;
1187 write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
1188 spin_unlock_irqrestore(&zs_lock, flags);
1189 }
1190
1191 static int rs_ioctl(struct tty_struct *tty, struct file * file,
1192 unsigned int cmd, unsigned long arg)
1193 {
1194 struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1195
1196 if (info->hook)
1197 return -ENODEV;
1198
1199 if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1200 return -ENODEV;
1201
1202 if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
1203 (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD) &&
1204 (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT)) {
1205 if (tty->flags & (1 << TTY_IO_ERROR))
1206 return -EIO;
1207 }
1208
1209 switch (cmd) {
1210 case TIOCGSERIAL:
1211 if (!access_ok(VERIFY_WRITE, (void *)arg,
1212 sizeof(struct serial_struct)))
1213 return -EFAULT;
1214 return get_serial_info(info, (struct serial_struct *)arg);
1215
1216 case TIOCSSERIAL:
1217 return set_serial_info(info, (struct serial_struct *)arg);
1218
1219 case TIOCSERGETLSR: /* Get line status register */
1220 if (!access_ok(VERIFY_WRITE, (void *)arg,
1221 sizeof(unsigned int)))
1222 return -EFAULT;
1223 return get_lsr_info(info, (unsigned int *)arg);
1224
1225 case TIOCSERGSTRUCT:
1226 if (!access_ok(VERIFY_WRITE, (void *)arg,
1227 sizeof(struct dec_serial)))
1228 return -EFAULT;
1229 copy_from_user((struct dec_serial *)arg, info,
1230 sizeof(struct dec_serial));
1231 return 0;
1232
1233 default:
1234 return -ENOIOCTLCMD;
1235 }
1236 return 0;
1237 }
1238
1239 static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
1240 {
1241 struct dec_serial *info = (struct dec_serial *)tty->driver_data;
1242 int was_stopped;
1243
1244 if (tty->termios->c_cflag == old_termios->c_cflag)
1245 return;
1246 was_stopped = info->tx_stopped;
1247
1248 change_speed(info);
1249
1250 if (was_stopped && !info->tx_stopped)
1251 rs_start(tty);
1252 }
1253
1254 /*
1255 * ------------------------------------------------------------
1256 * rs_close()
1257 *
1258 * This routine is called when the serial port gets closed.
1259 * Wait for the last remaining data to be sent.
1260 * ------------------------------------------------------------
1261 */
1262 static void rs_close(struct tty_struct *tty, struct file * filp)
1263 {
1264 struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1265 unsigned long flags;
1266
1267 if (!info || serial_paranoia_check(info, tty->name, "rs_close"))
1268 return;
1269
1270 spin_lock_irqsave(&zs_lock, flags);
1271
1272 if (tty_hung_up_p(filp)) {
1273 spin_unlock_irqrestore(&zs_lock, flags);
1274 return;
1275 }
1276
1277 #ifdef SERIAL_DEBUG_OPEN
1278 printk("rs_close ttyS%d, count = %d\n", info->line, info->count);
1279 #endif
1280 if ((tty->count == 1) && (info->count != 1)) {
1281 /*
1282 * Uh, oh. tty->count is 1, which means that the tty
1283 * structure will be freed. Info->count should always
1284 * be one in these conditions. If it's greater than
1285 * one, we've got real problems, since it means the
1286 * serial port won't be shutdown.
1287 */
1288 printk("rs_close: bad serial port count; tty->count is 1, "
1289 "info->count is %d\n", info->count);
1290 info->count = 1;
1291 }
1292 if (--info->count < 0) {
1293 printk("rs_close: bad serial port count for ttyS%d: %d\n",
1294 info->line, info->count);
1295 info->count = 0;
1296 }
1297 if (info->count) {
1298 spin_unlock_irqrestore(&zs_lock, flags);
1299 return;
1300 }
1301 info->flags |= ZILOG_CLOSING;
1302 /*
1303 * Now we wait for the transmit buffer to clear; and we notify
1304 * the line discipline to only process XON/XOFF characters.
1305 */
1306 tty->closing = 1;
1307 if (info->closing_wait != ZILOG_CLOSING_WAIT_NONE)
1308 tty_wait_until_sent(tty, info->closing_wait);
1309 /*
1310 * At this point we stop accepting input. To do this, we
1311 * disable the receiver and receive interrupts.
1312 */
1313 info->zs_channel->curregs[3] &= ~RxENABLE;
1314 write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
1315 info->zs_channel->curregs[1] = 0; /* disable any rx ints */
1316 write_zsreg(info->zs_channel, 1, info->zs_channel->curregs[1]);
1317 ZS_CLEARFIFO(info->zs_channel);
1318 if (info->flags & ZILOG_INITIALIZED) {
1319 /*
1320 * Before we drop DTR, make sure the SCC transmitter
1321 * has completely drained.
1322 */
1323 rs_wait_until_sent(tty, info->timeout);
1324 }
1325
1326 shutdown(info);
1327 if (tty->driver->flush_buffer)
1328 tty->driver->flush_buffer(tty);
1329 tty_ldisc_flush(tty);
1330 tty->closing = 0;
1331 info->event = 0;
1332 info->tty = 0;
1333 if (info->blocked_open) {
1334 if (info->close_delay) {
1335 msleep_interruptible(jiffies_to_msecs(info->close_delay));
1336 }
1337 wake_up_interruptible(&info->open_wait);
1338 }
1339 info->flags &= ~(ZILOG_NORMAL_ACTIVE|ZILOG_CLOSING);
1340 wake_up_interruptible(&info->close_wait);
1341 spin_unlock_irqrestore(&zs_lock, flags);
1342 }
1343
1344 /*
1345 * rs_wait_until_sent() --- wait until the transmitter is empty
1346 */
1347 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
1348 {
1349 struct dec_serial *info = (struct dec_serial *) tty->driver_data;
1350 unsigned long orig_jiffies;
1351 int char_time;
1352
1353 if (serial_paranoia_check(info, tty->name, "rs_wait_until_sent"))
1354 return;
1355
1356 orig_jiffies = jiffies;
1357 /*
1358 * Set the check interval to be 1/5 of the estimated time to
1359 * send a single character, and make it at least 1. The check
1360 * interval should also be less than the timeout.
1361 */
1362 char_time = (info->timeout - HZ/50) / info->xmit_fifo_size;
1363 char_time = char_time / 5;
1364 if (char_time == 0)
1365 char_time = 1;
1366 if (timeout)
1367 char_time = min(char_time, timeout);
1368 while ((read_zsreg(info->zs_channel, 1) & Tx_BUF_EMP) == 0) {
1369 msleep_interruptible(jiffies_to_msecs(char_time));
1370 if (signal_pending(current))
1371 break;
1372 if (timeout && time_after(jiffies, orig_jiffies + timeout))
1373 break;
1374 }
1375 current->state = TASK_RUNNING;
1376 }
1377
1378 /*
1379 * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
1380 */
1381 static void rs_hangup(struct tty_struct *tty)
1382 {
1383 struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1384
1385 if (serial_paranoia_check(info, tty->name, "rs_hangup"))
1386 return;
1387
1388 rs_flush_buffer(tty);
1389 shutdown(info);
1390 info->event = 0;
1391 info->count = 0;
1392 info->flags &= ~ZILOG_NORMAL_ACTIVE;
1393 info->tty = 0;
1394 wake_up_interruptible(&info->open_wait);
1395 }
1396
1397 /*
1398 * ------------------------------------------------------------
1399 * rs_open() and friends
1400 * ------------------------------------------------------------
1401 */
1402 static int block_til_ready(struct tty_struct *tty, struct file * filp,
1403 struct dec_serial *info)
1404 {
1405 DECLARE_WAITQUEUE(wait, current);
1406 int retval;
1407 int do_clocal = 0;
1408
1409 /*
1410 * If the device is in the middle of being closed, then block
1411 * until it's done, and then try again.
1412 */
1413 if (info->flags & ZILOG_CLOSING) {
1414 interruptible_sleep_on(&info->close_wait);
1415 #ifdef SERIAL_DO_RESTART
1416 return ((info->flags & ZILOG_HUP_NOTIFY) ?
1417 -EAGAIN : -ERESTARTSYS);
1418 #else
1419 return -EAGAIN;
1420 #endif
1421 }
1422
1423 /*
1424 * If non-blocking mode is set, or the port is not enabled,
1425 * then make the check up front and then exit.
1426 */
1427 if ((filp->f_flags & O_NONBLOCK) ||
1428 (tty->flags & (1 << TTY_IO_ERROR))) {
1429 info->flags |= ZILOG_NORMAL_ACTIVE;
1430 return 0;
1431 }
1432
1433 if (tty->termios->c_cflag & CLOCAL)
1434 do_clocal = 1;
1435
1436 /*
1437 * Block waiting for the carrier detect and the line to become
1438 * free (i.e., not in use by the callout). While we are in
1439 * this loop, info->count is dropped by one, so that
1440 * rs_close() knows when to free things. We restore it upon
1441 * exit, either normal or abnormal.
1442 */
1443 retval = 0;
1444 add_wait_queue(&info->open_wait, &wait);
1445 #ifdef SERIAL_DEBUG_OPEN
1446 printk("block_til_ready before block: ttyS%d, count = %d\n",
1447 info->line, info->count);
1448 #endif
1449 spin_lock(&zs_lock);
1450 if (!tty_hung_up_p(filp))
1451 info->count--;
1452 spin_unlock_irq(&zs_lock);
1453 info->blocked_open++;
1454 while (1) {
1455 spin_lock(&zs_lock);
1456 if (tty->termios->c_cflag & CBAUD)
1457 zs_rtsdtr(info, RTS | DTR, 1);
1458 spin_unlock_irq(&zs_lock);
1459 set_current_state(TASK_INTERRUPTIBLE);
1460 if (tty_hung_up_p(filp) ||
1461 !(info->flags & ZILOG_INITIALIZED)) {
1462 #ifdef SERIAL_DO_RESTART
1463 if (info->flags & ZILOG_HUP_NOTIFY)
1464 retval = -EAGAIN;
1465 else
1466 retval = -ERESTARTSYS;
1467 #else
1468 retval = -EAGAIN;
1469 #endif
1470 break;
1471 }
1472 if (!(info->flags & ZILOG_CLOSING) &&
1473 (do_clocal || (read_zsreg(info->zs_channel, 0) & DCD)))
1474 break;
1475 if (signal_pending(current)) {
1476 retval = -ERESTARTSYS;
1477 break;
1478 }
1479 #ifdef SERIAL_DEBUG_OPEN
1480 printk("block_til_ready blocking: ttyS%d, count = %d\n",
1481 info->line, info->count);
1482 #endif
1483 schedule();
1484 }
1485 current->state = TASK_RUNNING;
1486 remove_wait_queue(&info->open_wait, &wait);
1487 if (!tty_hung_up_p(filp))
1488 info->count++;
1489 info->blocked_open--;
1490 #ifdef SERIAL_DEBUG_OPEN
1491 printk("block_til_ready after blocking: ttyS%d, count = %d\n",
1492 info->line, info->count);
1493 #endif
1494 if (retval)
1495 return retval;
1496 info->flags |= ZILOG_NORMAL_ACTIVE;
1497 return 0;
1498 }
1499
1500 /*
1501 * This routine is called whenever a serial port is opened. It
1502 * enables interrupts for a serial port, linking in its ZILOG structure into
1503 * the IRQ chain. It also performs the serial-specific
1504 * initialization for the tty structure.
1505 */
1506 static int rs_open(struct tty_struct *tty, struct file * filp)
1507 {
1508 struct dec_serial *info;
1509 int retval, line;
1510
1511 line = tty->index;
1512 if ((line < 0) || (line >= zs_channels_found))
1513 return -ENODEV;
1514 info = zs_soft + line;
1515
1516 if (info->hook)
1517 return -ENODEV;
1518
1519 if (serial_paranoia_check(info, tty->name, "rs_open"))
1520 return -ENODEV;
1521 #ifdef SERIAL_DEBUG_OPEN
1522 printk("rs_open %s, count = %d\n", tty->name, info->count);
1523 #endif
1524
1525 info->count++;
1526 tty->driver_data = info;
1527 info->tty = tty;
1528
1529 /*
1530 * If the port is the middle of closing, bail out now
1531 */
1532 if (tty_hung_up_p(filp) ||
1533 (info->flags & ZILOG_CLOSING)) {
1534 if (info->flags & ZILOG_CLOSING)
1535 interruptible_sleep_on(&info->close_wait);
1536 #ifdef SERIAL_DO_RESTART
1537 return ((info->flags & ZILOG_HUP_NOTIFY) ?
1538 -EAGAIN : -ERESTARTSYS);
1539 #else
1540 return -EAGAIN;
1541 #endif
1542 }
1543
1544 /*
1545 * Start up serial port
1546 */
1547 retval = zs_startup(info);
1548 if (retval)
1549 return retval;
1550
1551 retval = block_til_ready(tty, filp, info);
1552 if (retval) {
1553 #ifdef SERIAL_DEBUG_OPEN
1554 printk("rs_open returning after block_til_ready with %d\n",
1555 retval);
1556 #endif
1557 return retval;
1558 }
1559
1560 #ifdef CONFIG_SERIAL_DEC_CONSOLE
1561 if (sercons.cflag && sercons.index == line) {
1562 tty->termios->c_cflag = sercons.cflag;
1563 sercons.cflag = 0;
1564 change_speed(info);
1565 }
1566 #endif
1567
1568 #ifdef SERIAL_DEBUG_OPEN
1569 printk("rs_open %s successful...", tty->name);
1570 #endif
1571 /* tty->low_latency = 1; */
1572 return 0;
1573 }
1574
1575 /* Finally, routines used to initialize the serial driver. */
1576
1577 static void __init show_serial_version(void)
1578 {
1579 printk("DECstation Z8530 serial driver version 0.09\n");
1580 }
1581
1582 /* Initialize Z8530s zs_channels
1583 */
1584
1585 static void __init probe_sccs(void)
1586 {
1587 struct dec_serial **pp;
1588 int i, n, n_chips = 0, n_channels, chip, channel;
1589 unsigned long flags;
1590
1591 /*
1592 * did we get here by accident?
1593 */
1594 if(!BUS_PRESENT) {
1595 printk("Not on JUNKIO machine, skipping probe_sccs\n");
1596 return;
1597 }
1598
1599 switch(mips_machtype) {
1600 #ifdef CONFIG_MACH_DECSTATION
1601 case MACH_DS5000_2X0:
1602 case MACH_DS5900:
1603 n_chips = 2;
1604 zs_parms = &ds_parms;
1605 zs_parms->irq0 = dec_interrupt[DEC_IRQ_SCC0];
1606 zs_parms->irq1 = dec_interrupt[DEC_IRQ_SCC1];
1607 break;
1608 case MACH_DS5000_1XX:
1609 n_chips = 2;
1610 zs_parms = &ds_parms;
1611 zs_parms->irq0 = dec_interrupt[DEC_IRQ_SCC0];
1612 zs_parms->irq1 = dec_interrupt[DEC_IRQ_SCC1];
1613 break;
1614 case MACH_DS5000_XX:
1615 n_chips = 1;
1616 zs_parms = &ds_parms;
1617 zs_parms->irq0 = dec_interrupt[DEC_IRQ_SCC0];
1618 break;
1619 #endif
1620 default:
1621 panic("zs: unsupported bus");
1622 }
1623 if (!zs_parms)
1624 panic("zs: uninitialized parms");
1625
1626 pp = &zs_chain;
1627
1628 n_channels = 0;
1629
1630 for (chip = 0; chip < n_chips; chip++) {
1631 for (channel = 0; channel <= 1; channel++) {
1632 /*
1633 * The sccs reside on the high byte of the 16 bit IOBUS
1634 */
1635 zs_channels[n_channels].control =
1636 (volatile void *)CKSEG1ADDR(dec_kn_slot_base +
1637 (0 == chip ? zs_parms->scc0 : zs_parms->scc1) +
1638 (0 == channel ? zs_parms->channel_a_offset :
1639 zs_parms->channel_b_offset));
1640 zs_channels[n_channels].data =
1641 zs_channels[n_channels].control + 4;
1642
1643 #ifndef CONFIG_SERIAL_DEC_CONSOLE
1644 /*
1645 * We're called early and memory managment isn't up, yet.
1646 * Thus request_region would fail.
1647 */
1648 if (!request_region((unsigned long)
1649 zs_channels[n_channels].control,
1650 ZS_CHAN_IO_SIZE, "SCC"))
1651 panic("SCC I/O region is not free");
1652 #endif
1653 zs_soft[n_channels].zs_channel = &zs_channels[n_channels];
1654 /* HACK alert! */
1655 if (!(chip & 1))
1656 zs_soft[n_channels].irq = zs_parms->irq0;
1657 else
1658 zs_soft[n_channels].irq = zs_parms->irq1;
1659
1660 /*
1661 * Identification of channel A. Location of channel A
1662 * inside chip depends on mapping of internal address
1663 * the chip decodes channels by.
1664 * CHANNEL_A_NR returns either 0 (in case of
1665 * DECstations) or 1 (in case of Baget).
1666 */
1667 if (CHANNEL_A_NR == channel)
1668 zs_soft[n_channels].zs_chan_a =
1669 &zs_channels[n_channels+1-2*CHANNEL_A_NR];
1670 else
1671 zs_soft[n_channels].zs_chan_a =
1672 &zs_channels[n_channels];
1673
1674 *pp = &zs_soft[n_channels];
1675 pp = &zs_soft[n_channels].zs_next;
1676 n_channels++;
1677 }
1678 }
1679
1680 *pp = 0;
1681 zs_channels_found = n_channels;
1682
1683 for (n = 0; n < zs_channels_found; n++) {
1684 for (i = 0; i < 16; i++) {
1685 zs_soft[n].zs_channel->curregs[i] = zs_init_regs[i];
1686 }
1687 }
1688
1689 spin_lock_irqsave(&zs_lock, flags);
1690 for (n = 0; n < zs_channels_found; n++) {
1691 if (n % 2 == 0) {
1692 write_zsreg(zs_soft[n].zs_chan_a, R9, FHWRES);
1693 udelay(10);
1694 write_zsreg(zs_soft[n].zs_chan_a, R9, 0);
1695 }
1696 load_zsregs(zs_soft[n].zs_channel,
1697 zs_soft[n].zs_channel->curregs);
1698 }
1699 spin_unlock_irqrestore(&zs_lock, flags);
1700 }
1701
1702 static const struct tty_operations serial_ops = {
1703 .open = rs_open,
1704 .close = rs_close,
1705 .write = rs_write,
1706 .flush_chars = rs_flush_chars,
1707 .write_room = rs_write_room,
1708 .chars_in_buffer = rs_chars_in_buffer,
1709 .flush_buffer = rs_flush_buffer,
1710 .ioctl = rs_ioctl,
1711 .throttle = rs_throttle,
1712 .unthrottle = rs_unthrottle,
1713 .set_termios = rs_set_termios,
1714 .stop = rs_stop,
1715 .start = rs_start,
1716 .hangup = rs_hangup,
1717 .break_ctl = rs_break,
1718 .wait_until_sent = rs_wait_until_sent,
1719 .tiocmget = rs_tiocmget,
1720 .tiocmset = rs_tiocmset,
1721 };
1722
1723 /* zs_init inits the driver */
1724 int __init zs_init(void)
1725 {
1726 int channel, i;
1727 struct dec_serial *info;
1728
1729 if(!BUS_PRESENT)
1730 return -ENODEV;
1731
1732 /* Find out how many Z8530 SCCs we have */
1733 if (zs_chain == 0)
1734 probe_sccs();
1735 serial_driver = alloc_tty_driver(zs_channels_found);
1736 if (!serial_driver)
1737 return -ENOMEM;
1738
1739 show_serial_version();
1740
1741 /* Initialize the tty_driver structure */
1742 /* Not all of this is exactly right for us. */
1743
1744 serial_driver->owner = THIS_MODULE;
1745 serial_driver->name = "ttyS";
1746 serial_driver->major = TTY_MAJOR;
1747 serial_driver->minor_start = 64;
1748 serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
1749 serial_driver->subtype = SERIAL_TYPE_NORMAL;
1750 serial_driver->init_termios = tty_std_termios;
1751 serial_driver->init_termios.c_cflag =
1752 B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1753 serial_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1754 tty_set_operations(serial_driver, &serial_ops);
1755
1756 if (tty_register_driver(serial_driver))
1757 panic("Couldn't register serial driver");
1758
1759 for (info = zs_chain, i = 0; info; info = info->zs_next, i++) {
1760
1761 /* Needed before interrupts are enabled. */
1762 info->tty = 0;
1763 info->x_char = 0;
1764
1765 if (info->hook && info->hook->init_info) {
1766 (*info->hook->init_info)(info);
1767 continue;
1768 }
1769
1770 info->magic = SERIAL_MAGIC;
1771 info->port = (int) info->zs_channel->control;
1772 info->line = i;
1773 info->custom_divisor = 16;
1774 info->close_delay = 50;
1775 info->closing_wait = 3000;
1776 info->event = 0;
1777 info->count = 0;
1778 info->blocked_open = 0;
1779 tasklet_init(&info->tlet, do_softint, (unsigned long)info);
1780 init_waitqueue_head(&info->open_wait);
1781 init_waitqueue_head(&info->close_wait);
1782 printk("ttyS%02d at 0x%08x (irq = %d) is a Z85C30 SCC\n",
1783 info->line, info->port, info->irq);
1784 tty_register_device(serial_driver, info->line, NULL);
1785
1786 }
1787
1788 for (channel = 0; channel < zs_channels_found; ++channel) {
1789 zs_soft[channel].clk_divisor = 16;
1790 zs_soft[channel].zs_baud = get_zsbaud(&zs_soft[channel]);
1791
1792 if (request_irq(zs_soft[channel].irq, rs_interrupt, IRQF_SHARED,
1793 "scc", &zs_soft[channel]))
1794 printk(KERN_ERR "decserial: can't get irq %d\n",
1795 zs_soft[channel].irq);
1796
1797 if (zs_soft[channel].hook) {
1798 zs_startup(&zs_soft[channel]);
1799 if (zs_soft[channel].hook->init_channel)
1800 (*zs_soft[channel].hook->init_channel)
1801 (&zs_soft[channel]);
1802 }
1803 }
1804
1805 return 0;
1806 }
1807
1808 /*
1809 * polling I/O routines
1810 */
1811 static int zs_poll_tx_char(void *handle, unsigned char ch)
1812 {
1813 struct dec_serial *info = handle;
1814 struct dec_zschannel *chan = info->zs_channel;
1815 int ret;
1816
1817 if(chan) {
1818 int loops = 10000;
1819
1820 while (loops && !(read_zsreg(chan, 0) & Tx_BUF_EMP))
1821 loops--;
1822
1823 if (loops) {
1824 write_zsdata(chan, ch);
1825 ret = 0;
1826 } else
1827 ret = -EAGAIN;
1828
1829 return ret;
1830 } else
1831 return -ENODEV;
1832 }
1833
1834 static int zs_poll_rx_char(void *handle)
1835 {
1836 struct dec_serial *info = handle;
1837 struct dec_zschannel *chan = info->zs_channel;
1838 int ret;
1839
1840 if(chan) {
1841 int loops = 10000;
1842
1843 while (loops && !(read_zsreg(chan, 0) & Rx_CH_AV))
1844 loops--;
1845
1846 if (loops)
1847 ret = read_zsdata(chan);
1848 else
1849 ret = -EAGAIN;
1850
1851 return ret;
1852 } else
1853 return -ENODEV;
1854 }
1855
1856 int register_zs_hook(unsigned int channel, struct dec_serial_hook *hook)
1857 {
1858 struct dec_serial *info = &zs_soft[channel];
1859
1860 if (info->hook) {
1861 printk("%s: line %d has already a hook registered\n",
1862 __FUNCTION__, channel);
1863
1864 return 0;
1865 } else {
1866 hook->poll_rx_char = zs_poll_rx_char;
1867 hook->poll_tx_char = zs_poll_tx_char;
1868 info->hook = hook;
1869
1870 return 1;
1871 }
1872 }
1873
1874 int unregister_zs_hook(unsigned int channel)
1875 {
1876 struct dec_serial *info = &zs_soft[channel];
1877
1878 if (info->hook) {
1879 info->hook = NULL;
1880 return 1;
1881 } else {
1882 printk("%s: trying to unregister hook on line %d,"
1883 " but none is registered\n", __FUNCTION__, channel);
1884 return 0;
1885 }
1886 }
1887
1888 /*
1889 * ------------------------------------------------------------
1890 * Serial console driver
1891 * ------------------------------------------------------------
1892 */
1893 #ifdef CONFIG_SERIAL_DEC_CONSOLE
1894
1895
1896 /*
1897 * Print a string to the serial port trying not to disturb
1898 * any possible real use of the port...
1899 */
1900 static void serial_console_write(struct console *co, const char *s,
1901 unsigned count)
1902 {
1903 struct dec_serial *info;
1904 int i;
1905
1906 info = zs_soft + co->index;
1907
1908 for (i = 0; i < count; i++, s++) {
1909 if(*s == '\n')
1910 zs_poll_tx_char(info, '\r');
1911 zs_poll_tx_char(info, *s);
1912 }
1913 }
1914
1915 static struct tty_driver *serial_console_device(struct console *c, int *index)
1916 {
1917 *index = c->index;
1918 return serial_driver;
1919 }
1920
1921 /*
1922 * Setup initial baud/bits/parity. We do two things here:
1923 * - construct a cflag setting for the first rs_open()
1924 * - initialize the serial port
1925 * Return non-zero if we didn't find a serial port.
1926 */
1927 static int __init serial_console_setup(struct console *co, char *options)
1928 {
1929 struct dec_serial *info;
1930 int baud = 9600;
1931 int bits = 8;
1932 int parity = 'n';
1933 int cflag = CREAD | HUPCL | CLOCAL;
1934 int clk_divisor = 16;
1935 int brg;
1936 char *s;
1937 unsigned long flags;
1938
1939 if(!BUS_PRESENT)
1940 return -ENODEV;
1941
1942 info = zs_soft + co->index;
1943
1944 if (zs_chain == 0)
1945 probe_sccs();
1946
1947 info->is_cons = 1;
1948
1949 if (options) {
1950 baud = simple_strtoul(options, NULL, 10);
1951 s = options;
1952 while(*s >= '0' && *s <= '9')
1953 s++;
1954 if (*s)
1955 parity = *s++;
1956 if (*s)
1957 bits = *s - '0';
1958 }
1959
1960 /*
1961 * Now construct a cflag setting.
1962 */
1963 switch(baud) {
1964 case 1200:
1965 cflag |= B1200;
1966 break;
1967 case 2400:
1968 cflag |= B2400;
1969 break;
1970 case 4800:
1971 cflag |= B4800;
1972 break;
1973 case 19200:
1974 cflag |= B19200;
1975 break;
1976 case 38400:
1977 cflag |= B38400;
1978 break;
1979 case 57600:
1980 cflag |= B57600;
1981 break;
1982 case 115200:
1983 cflag |= B115200;
1984 break;
1985 case 9600:
1986 default:
1987 cflag |= B9600;
1988 /*
1989 * Set this to a sane value to prevent a divide error.
1990 */
1991 baud = 9600;
1992 break;
1993 }
1994 switch(bits) {
1995 case 7:
1996 cflag |= CS7;
1997 break;
1998 default:
1999 case 8:
2000 cflag |= CS8;
2001 break;
2002 }
2003 switch(parity) {
2004 case 'o': case 'O':
2005 cflag |= PARODD;
2006 break;
2007 case 'e': case 'E':
2008 cflag |= PARENB;
2009 break;
2010 }
2011 co->cflag = cflag;
2012
2013 spin_lock_irqsave(&zs_lock, flags);
2014
2015 /*
2016 * Set up the baud rate generator.
2017 */
2018 brg = BPS_TO_BRG(baud, zs_parms->clock / clk_divisor);
2019 info->zs_channel->curregs[R12] = (brg & 255);
2020 info->zs_channel->curregs[R13] = ((brg >> 8) & 255);
2021
2022 /*
2023 * Set byte size and parity.
2024 */
2025 if (bits == 7) {
2026 info->zs_channel->curregs[R3] |= Rx7;
2027 info->zs_channel->curregs[R5] |= Tx7;
2028 } else {
2029 info->zs_channel->curregs[R3] |= Rx8;
2030 info->zs_channel->curregs[R5] |= Tx8;
2031 }
2032 if (cflag & PARENB) {
2033 info->zs_channel->curregs[R4] |= PAR_ENA;
2034 }
2035 if (!(cflag & PARODD)) {
2036 info->zs_channel->curregs[R4] |= PAR_EVEN;
2037 }
2038 info->zs_channel->curregs[R4] |= SB1;
2039
2040 /*
2041 * Turn on RTS and DTR.
2042 */
2043 zs_rtsdtr(info, RTS | DTR, 1);
2044
2045 /*
2046 * Finally, enable sequencing.
2047 */
2048 info->zs_channel->curregs[R3] |= RxENABLE;
2049 info->zs_channel->curregs[R5] |= TxENAB;
2050
2051 /*
2052 * Clear the interrupt registers.
2053 */
2054 write_zsreg(info->zs_channel, R0, ERR_RES);
2055 write_zsreg(info->zs_channel, R0, RES_H_IUS);
2056
2057 /*
2058 * Load up the new values.
2059 */
2060 load_zsregs(info->zs_channel, info->zs_channel->curregs);
2061
2062 /* Save the current value of RR0 */
2063 info->read_reg_zero = read_zsreg(info->zs_channel, R0);
2064
2065 zs_soft[co->index].clk_divisor = clk_divisor;
2066 zs_soft[co->index].zs_baud = get_zsbaud(&zs_soft[co->index]);
2067
2068 spin_unlock_irqrestore(&zs_lock, flags);
2069
2070 return 0;
2071 }
2072
2073 static struct console sercons = {
2074 .name = "ttyS",
2075 .write = serial_console_write,
2076 .device = serial_console_device,
2077 .setup = serial_console_setup,
2078 .flags = CON_PRINTBUFFER,
2079 .index = -1,
2080 };
2081
2082 /*
2083 * Register console.
2084 */
2085 void __init zs_serial_console_init(void)
2086 {
2087 register_console(&sercons);
2088 }
2089 #endif /* ifdef CONFIG_SERIAL_DEC_CONSOLE */
2090
2091 #ifdef CONFIG_KGDB
2092 struct dec_zschannel *zs_kgdbchan;
2093 static unsigned char scc_inittab[] = {
2094 9, 0x80, /* reset A side (CHRA) */
2095 13, 0, /* set baud rate divisor */
2096 12, 1,
2097 14, 1, /* baud rate gen enable, src=rtxc (BRENABL) */
2098 11, 0x50, /* clocks = br gen (RCBR | TCBR) */
2099 5, 0x6a, /* tx 8 bits, assert RTS (Tx8 | TxENAB | RTS) */
2100 4, 0x44, /* x16 clock, 1 stop (SB1 | X16CLK)*/
2101 3, 0xc1, /* rx enable, 8 bits (RxENABLE | Rx8)*/
2102 };
2103
2104 /* These are for receiving and sending characters under the kgdb
2105 * source level kernel debugger.
2106 */
2107 void putDebugChar(char kgdb_char)
2108 {
2109 struct dec_zschannel *chan = zs_kgdbchan;
2110 while ((read_zsreg(chan, 0) & Tx_BUF_EMP) == 0)
2111 RECOVERY_DELAY;
2112 write_zsdata(chan, kgdb_char);
2113 }
2114 char getDebugChar(void)
2115 {
2116 struct dec_zschannel *chan = zs_kgdbchan;
2117 while((read_zsreg(chan, 0) & Rx_CH_AV) == 0)
2118 eieio(); /*barrier();*/
2119 return read_zsdata(chan);
2120 }
2121 void kgdb_interruptible(int yes)
2122 {
2123 struct dec_zschannel *chan = zs_kgdbchan;
2124 int one, nine;
2125 nine = read_zsreg(chan, 9);
2126 if (yes == 1) {
2127 one = EXT_INT_ENAB|RxINT_ALL;
2128 nine |= MIE;
2129 printk("turning serial ints on\n");
2130 } else {
2131 one = RxINT_DISAB;
2132 nine &= ~MIE;
2133 printk("turning serial ints off\n");
2134 }
2135 write_zsreg(chan, 1, one);
2136 write_zsreg(chan, 9, nine);
2137 }
2138
2139 static int kgdbhook_init_channel(void *handle)
2140 {
2141 return 0;
2142 }
2143
2144 static void kgdbhook_init_info(void *handle)
2145 {
2146 }
2147
2148 static void kgdbhook_rx_char(void *handle, unsigned char ch, unsigned char fl)
2149 {
2150 struct dec_serial *info = handle;
2151
2152 if (fl != TTY_NORMAL)
2153 return;
2154 if (ch == 0x03 || ch == '$')
2155 breakpoint();
2156 }
2157
2158 /* This sets up the serial port we're using, and turns on
2159 * interrupts for that channel, so kgdb is usable once we're done.
2160 */
2161 static inline void kgdb_chaninit(struct dec_zschannel *ms, int intson, int bps)
2162 {
2163 int brg;
2164 int i, x;
2165 volatile char *sccc = ms->control;
2166 brg = BPS_TO_BRG(bps, zs_parms->clock/16);
2167 printk("setting bps on kgdb line to %d [brg=%x]\n", bps, brg);
2168 for (i = 20000; i != 0; --i) {
2169 x = *sccc; eieio();
2170 }
2171 for (i = 0; i < sizeof(scc_inittab); ++i) {
2172 write_zsreg(ms, scc_inittab[i], scc_inittab[i+1]);
2173 i++;
2174 }
2175 }
2176 /* This is called at boot time to prime the kgdb serial debugging
2177 * serial line. The 'tty_num' argument is 0 for /dev/ttya and 1
2178 * for /dev/ttyb which is determined in setup_arch() from the
2179 * boot command line flags.
2180 */
2181 struct dec_serial_hook zs_kgdbhook = {
2182 .init_channel = kgdbhook_init_channel,
2183 .init_info = kgdbhook_init_info,
2184 .rx_char = kgdbhook_rx_char,
2185 .cflags = B38400 | CS8 | CLOCAL,
2186 }
2187
2188 void __init zs_kgdb_hook(int tty_num)
2189 {
2190 /* Find out how many Z8530 SCCs we have */
2191 if (zs_chain == 0)
2192 probe_sccs();
2193 zs_soft[tty_num].zs_channel = &zs_channels[tty_num];
2194 zs_kgdbchan = zs_soft[tty_num].zs_channel;
2195 zs_soft[tty_num].change_needed = 0;
2196 zs_soft[tty_num].clk_divisor = 16;
2197 zs_soft[tty_num].zs_baud = 38400;
2198 zs_soft[tty_num].hook = &zs_kgdbhook; /* This runs kgdb */
2199 /* Turn on transmitter/receiver at 8-bits/char */
2200 kgdb_chaninit(zs_soft[tty_num].zs_channel, 1, 38400);
2201 printk("KGDB: on channel %d initialized\n", tty_num);
2202 set_debug_traps(); /* init stub */
2203 }
2204 #endif /* ifdef CONFIG_KGDB */
linux kernel for loongson