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1/*
2 * dz.c: Serial port driver for DECstations equipped
3 *       with the DZ chipset.
4 *
5 * Copyright (C) 1998 Olivier A. D. Lebaillif
6 *
7 * Email: olivier.lebaillif@ifrsys.com
8 *
9 * Copyright (C) 2004, 2006, 2007  Maciej W. Rozycki
10 *
11 * [31-AUG-98] triemer
12 * Changed IRQ to use Harald's dec internals interrupts.h
13 * removed base_addr code - moving address assignment to setup.c
14 * Changed name of dz_init to rs_init to be consistent with tc code
15 * [13-NOV-98] triemer fixed code to receive characters
16 *    after patches by harald to irq code.
17 * [09-JAN-99] triemer minor fix for schedule - due to removal of timeout
18 *            field from "current" - somewhere between 2.1.121 and 2.1.131
19 Qua Jun 27 15:02:26 BRT 2001
20 * [27-JUN-2001] Arnaldo Carvalho de Melo <acme@conectiva.com.br> - cleanups
21 *
22 * Parts (C) 1999 David Airlie, airlied@linux.ie
23 * [07-SEP-99] Bugfixes
24 *
25 * [06-Jan-2002] Russell King <rmk@arm.linux.org.uk>
26 * Converted to new serial core
27 */
28
29#undef DEBUG_DZ
30
31#if defined(CONFIG_SERIAL_DZ_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
32#define SUPPORT_SYSRQ
33#endif
34
35#include <linux/bitops.h>
36#include <linux/compiler.h>
37#include <linux/console.h>
38#include <linux/delay.h>
39#include <linux/errno.h>
40#include <linux/init.h>
41#include <linux/interrupt.h>
42#include <linux/ioport.h>
43#include <linux/kernel.h>
44#include <linux/major.h>
45#include <linux/module.h>
46#include <linux/serial.h>
47#include <linux/serial_core.h>
48#include <linux/sysrq.h>
49#include <linux/tty.h>
50
51#include <asm/atomic.h>
52#include <asm/bootinfo.h>
53#include <asm/io.h>
54#include <asm/system.h>
55
56#include <asm/dec/interrupts.h>
57#include <asm/dec/kn01.h>
58#include <asm/dec/kn02.h>
59#include <asm/dec/machtype.h>
60#include <asm/dec/prom.h>
61#include <asm/dec/system.h>
62
63#include "dz.h"
64
65
66MODULE_DESCRIPTION("DECstation DZ serial driver");
67MODULE_LICENSE("GPL");
68
69
70static char dz_name[] __initdata = "DECstation DZ serial driver version ";
71static char dz_version[] __initdata = "1.04";
72
73struct dz_port {
74	struct dz_mux		*mux;
75	struct uart_port	port;
76	unsigned int		cflag;
77};
78
79struct dz_mux {
80	struct dz_port		dport[DZ_NB_PORT];
81	atomic_t		map_guard;
82	atomic_t		irq_guard;
83	int			initialised;
84};
85
86static struct dz_mux dz_mux;
87
88static inline struct dz_port *to_dport(struct uart_port *uport)
89{
90	return container_of(uport, struct dz_port, port);
91}
92
93/*
94 * ------------------------------------------------------------
95 * dz_in () and dz_out ()
96 *
97 * These routines are used to access the registers of the DZ
98 * chip, hiding relocation differences between implementation.
99 * ------------------------------------------------------------
100 */
101
102static u16 dz_in(struct dz_port *dport, unsigned offset)
103{
104	void __iomem *addr = dport->port.membase + offset;
105
106	return readw(addr);
107}
108
109static void dz_out(struct dz_port *dport, unsigned offset, u16 value)
110{
111	void __iomem *addr = dport->port.membase + offset;
112
113	writew(value, addr);
114}
115
116/*
117 * ------------------------------------------------------------
118 * rs_stop () and rs_start ()
119 *
120 * These routines are called before setting or resetting
121 * tty->stopped. They enable or disable transmitter interrupts,
122 * as necessary.
123 * ------------------------------------------------------------
124 */
125
126static void dz_stop_tx(struct uart_port *uport)
127{
128	struct dz_port *dport = to_dport(uport);
129	u16 tmp, mask = 1 << dport->port.line;
130
131	tmp = dz_in(dport, DZ_TCR);	/* read the TX flag */
132	tmp &= ~mask;			/* clear the TX flag */
133	dz_out(dport, DZ_TCR, tmp);
134}
135
136static void dz_start_tx(struct uart_port *uport)
137{
138	struct dz_port *dport = to_dport(uport);
139	u16 tmp, mask = 1 << dport->port.line;
140
141	tmp = dz_in(dport, DZ_TCR);	/* read the TX flag */
142	tmp |= mask;			/* set the TX flag */
143	dz_out(dport, DZ_TCR, tmp);
144}
145
146static void dz_stop_rx(struct uart_port *uport)
147{
148	struct dz_port *dport = to_dport(uport);
149
150	dport->cflag &= ~DZ_RXENAB;
151	dz_out(dport, DZ_LPR, dport->cflag);
152}
153
154static void dz_enable_ms(struct uart_port *uport)
155{
156	/* nothing to do */
157}
158
159/*
160 * ------------------------------------------------------------
161 *
162 * Here start the interrupt handling routines.  All of the following
163 * subroutines are declared as inline and are folded into
164 * dz_interrupt.  They were separated out for readability's sake.
165 *
166 * Note: dz_interrupt() is a "fast" interrupt, which means that it
167 * runs with interrupts turned off.  People who may want to modify
168 * dz_interrupt() should try to keep the interrupt handler as fast as
169 * possible.  After you are done making modifications, it is not a bad
170 * idea to do:
171 *
172 *	make drivers/serial/dz.s
173 *
174 * and look at the resulting assemble code in dz.s.
175 *
176 * ------------------------------------------------------------
177 */
178
179/*
180 * ------------------------------------------------------------
181 * receive_char ()
182 *
183 * This routine deals with inputs from any lines.
184 * ------------------------------------------------------------
185 */
186static inline void dz_receive_chars(struct dz_mux *mux)
187{
188	struct uart_port *uport;
189	struct dz_port *dport = &mux->dport[0];
190	struct tty_struct *tty = NULL;
191	struct uart_icount *icount;
192	int lines_rx[DZ_NB_PORT] = { [0 ... DZ_NB_PORT - 1] = 0 };
193	unsigned char ch, flag;
194	u16 status;
195	int i;
196
197	while ((status = dz_in(dport, DZ_RBUF)) & DZ_DVAL) {
198		dport = &mux->dport[LINE(status)];
199		uport = &dport->port;
200		tty = uport->state->port.tty;	/* point to the proper dev */
201
202		ch = UCHAR(status);		/* grab the char */
203		flag = TTY_NORMAL;
204
205		icount = &uport->icount;
206		icount->rx++;
207
208		if (unlikely(status & (DZ_OERR | DZ_FERR | DZ_PERR))) {
209
210			/*
211			 * There is no separate BREAK status bit, so treat
212			 * null characters with framing errors as BREAKs;
213			 * normally, otherwise.  For this move the Framing
214			 * Error bit to a simulated BREAK bit.
215			 */
216			if (!ch) {
217				status |= (status & DZ_FERR) >>
218					  (ffs(DZ_FERR) - ffs(DZ_BREAK));
219				status &= ~DZ_FERR;
220			}
221
222			/* Handle SysRq/SAK & keep track of the statistics. */
223			if (status & DZ_BREAK) {
224				icount->brk++;
225				if (uart_handle_break(uport))
226					continue;
227			} else if (status & DZ_FERR)
228				icount->frame++;
229			else if (status & DZ_PERR)
230				icount->parity++;
231			if (status & DZ_OERR)
232				icount->overrun++;
233
234			status &= uport->read_status_mask;
235			if (status & DZ_BREAK)
236				flag = TTY_BREAK;
237			else if (status & DZ_FERR)
238				flag = TTY_FRAME;
239			else if (status & DZ_PERR)
240				flag = TTY_PARITY;
241
242		}
243
244		if (uart_handle_sysrq_char(uport, ch))
245			continue;
246
247		uart_insert_char(uport, status, DZ_OERR, ch, flag);
248		lines_rx[LINE(status)] = 1;
249	}
250	for (i = 0; i < DZ_NB_PORT; i++)
251		if (lines_rx[i])
252			tty_flip_buffer_push(mux->dport[i].port.state->port.tty);
253}
254
255/*
256 * ------------------------------------------------------------
257 * transmit_char ()
258 *
259 * This routine deals with outputs to any lines.
260 * ------------------------------------------------------------
261 */
262static inline void dz_transmit_chars(struct dz_mux *mux)
263{
264	struct dz_port *dport = &mux->dport[0];
265	struct circ_buf *xmit;
266	unsigned char tmp;
267	u16 status;
268
269	status = dz_in(dport, DZ_CSR);
270	dport = &mux->dport[LINE(status)];
271	xmit = &dport->port.state->xmit;
272
273	if (dport->port.x_char) {		/* XON/XOFF chars */
274		dz_out(dport, DZ_TDR, dport->port.x_char);
275		dport->port.icount.tx++;
276		dport->port.x_char = 0;
277		return;
278	}
279	/* If nothing to do or stopped or hardware stopped. */
280	if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {
281		spin_lock(&dport->port.lock);
282		dz_stop_tx(&dport->port);
283		spin_unlock(&dport->port.lock);
284		return;
285	}
286
287	/*
288	 * If something to do... (remember the dz has no output fifo,
289	 * so we go one char at a time) :-<
290	 */
291	tmp = xmit->buf[xmit->tail];
292	xmit->tail = (xmit->tail + 1) & (DZ_XMIT_SIZE - 1);
293	dz_out(dport, DZ_TDR, tmp);
294	dport->port.icount.tx++;
295
296	if (uart_circ_chars_pending(xmit) < DZ_WAKEUP_CHARS)
297		uart_write_wakeup(&dport->port);
298
299	/* Are we are done. */
300	if (uart_circ_empty(xmit)) {
301		spin_lock(&dport->port.lock);
302		dz_stop_tx(&dport->port);
303		spin_unlock(&dport->port.lock);
304	}
305}
306
307/*
308 * ------------------------------------------------------------
309 * check_modem_status()
310 *
311 * DS 3100 & 5100: Only valid for the MODEM line, duh!
312 * DS 5000/200: Valid for the MODEM and PRINTER line.
313 * ------------------------------------------------------------
314 */
315static inline void check_modem_status(struct dz_port *dport)
316{
317	u16 status;
318
319	/* If not the modem line just return.  */
320	if (dport->port.line != DZ_MODEM)
321		return;
322
323	status = dz_in(dport, DZ_MSR);
324
325	/* it's easy, since DSR2 is the only bit in the register */
326	if (status)
327		dport->port.icount.dsr++;
328}
329
330/*
331 * ------------------------------------------------------------
332 * dz_interrupt ()
333 *
334 * this is the main interrupt routine for the DZ chip.
335 * It deals with the multiple ports.
336 * ------------------------------------------------------------
337 */
338static irqreturn_t dz_interrupt(int irq, void *dev_id)
339{
340	struct dz_mux *mux = dev_id;
341	struct dz_port *dport = &mux->dport[0];
342	u16 status;
343
344	/* get the reason why we just got an irq */
345	status = dz_in(dport, DZ_CSR);
346
347	if ((status & (DZ_RDONE | DZ_RIE)) == (DZ_RDONE | DZ_RIE))
348		dz_receive_chars(mux);
349
350	if ((status & (DZ_TRDY | DZ_TIE)) == (DZ_TRDY | DZ_TIE))
351		dz_transmit_chars(mux);
352
353	return IRQ_HANDLED;
354}
355
356/*
357 * -------------------------------------------------------------------
358 * Here ends the DZ interrupt routines.
359 * -------------------------------------------------------------------
360 */
361
362static unsigned int dz_get_mctrl(struct uart_port *uport)
363{
364	struct dz_port *dport = to_dport(uport);
365	unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
366
367	if (dport->port.line == DZ_MODEM) {
368		if (dz_in(dport, DZ_MSR) & DZ_MODEM_DSR)
369			mctrl &= ~TIOCM_DSR;
370	}
371
372	return mctrl;
373}
374
375static void dz_set_mctrl(struct uart_port *uport, unsigned int mctrl)
376{
377	struct dz_port *dport = to_dport(uport);
378	u16 tmp;
379
380	if (dport->port.line == DZ_MODEM) {
381		tmp = dz_in(dport, DZ_TCR);
382		if (mctrl & TIOCM_DTR)
383			tmp &= ~DZ_MODEM_DTR;
384		else
385			tmp |= DZ_MODEM_DTR;
386		dz_out(dport, DZ_TCR, tmp);
387	}
388}
389
390/*
391 * -------------------------------------------------------------------
392 * startup ()
393 *
394 * various initialization tasks
395 * -------------------------------------------------------------------
396 */
397static int dz_startup(struct uart_port *uport)
398{
399	struct dz_port *dport = to_dport(uport);
400	struct dz_mux *mux = dport->mux;
401	unsigned long flags;
402	int irq_guard;
403	int ret;
404	u16 tmp;
405
406	irq_guard = atomic_add_return(1, &mux->irq_guard);
407	if (irq_guard != 1)
408		return 0;
409
410	ret = request_irq(dport->port.irq, dz_interrupt,
411			  IRQF_SHARED, "dz", mux);
412	if (ret) {
413		atomic_add(-1, &mux->irq_guard);
414		printk(KERN_ERR "dz: Cannot get IRQ %d!\n", dport->port.irq);
415		return ret;
416	}
417
418	spin_lock_irqsave(&dport->port.lock, flags);
419
420	/* Enable interrupts.  */
421	tmp = dz_in(dport, DZ_CSR);
422	tmp |= DZ_RIE | DZ_TIE;
423	dz_out(dport, DZ_CSR, tmp);
424
425	spin_unlock_irqrestore(&dport->port.lock, flags);
426
427	return 0;
428}
429
430/*
431 * -------------------------------------------------------------------
432 * shutdown ()
433 *
434 * This routine will shutdown a serial port; interrupts are disabled, and
435 * DTR is dropped if the hangup on close termio flag is on.
436 * -------------------------------------------------------------------
437 */
438static void dz_shutdown(struct uart_port *uport)
439{
440	struct dz_port *dport = to_dport(uport);
441	struct dz_mux *mux = dport->mux;
442	unsigned long flags;
443	int irq_guard;
444	u16 tmp;
445
446	spin_lock_irqsave(&dport->port.lock, flags);
447	dz_stop_tx(&dport->port);
448	spin_unlock_irqrestore(&dport->port.lock, flags);
449
450	irq_guard = atomic_add_return(-1, &mux->irq_guard);
451	if (!irq_guard) {
452		/* Disable interrupts.  */
453		tmp = dz_in(dport, DZ_CSR);
454		tmp &= ~(DZ_RIE | DZ_TIE);
455		dz_out(dport, DZ_CSR, tmp);
456
457		free_irq(dport->port.irq, mux);
458	}
459}
460
461/*
462 * -------------------------------------------------------------------
463 * dz_tx_empty() -- get the transmitter empty status
464 *
465 * Purpose: Let user call ioctl() to get info when the UART physically
466 *          is emptied.  On bus types like RS485, the transmitter must
467 *          release the bus after transmitting. This must be done when
468 *          the transmit shift register is empty, not be done when the
469 *          transmit holding register is empty.  This functionality
470 *          allows an RS485 driver to be written in user space.
471 * -------------------------------------------------------------------
472 */
473static unsigned int dz_tx_empty(struct uart_port *uport)
474{
475	struct dz_port *dport = to_dport(uport);
476	unsigned short tmp, mask = 1 << dport->port.line;
477
478	tmp = dz_in(dport, DZ_TCR);
479	tmp &= mask;
480
481	return tmp ? 0 : TIOCSER_TEMT;
482}
483
484static void dz_break_ctl(struct uart_port *uport, int break_state)
485{
486	struct dz_port *dport = to_dport(uport);
487	unsigned long flags;
488	unsigned short tmp, mask = 1 << dport->port.line;
489
490	spin_lock_irqsave(&uport->lock, flags);
491	tmp = dz_in(dport, DZ_TCR);
492	if (break_state)
493		tmp |= mask;
494	else
495		tmp &= ~mask;
496	dz_out(dport, DZ_TCR, tmp);
497	spin_unlock_irqrestore(&uport->lock, flags);
498}
499
500static int dz_encode_baud_rate(unsigned int baud)
501{
502	switch (baud) {
503	case 50:
504		return DZ_B50;
505	case 75:
506		return DZ_B75;
507	case 110:
508		return DZ_B110;
509	case 134:
510		return DZ_B134;
511	case 150:
512		return DZ_B150;
513	case 300:
514		return DZ_B300;
515	case 600:
516		return DZ_B600;
517	case 1200:
518		return DZ_B1200;
519	case 1800:
520		return DZ_B1800;
521	case 2000:
522		return DZ_B2000;
523	case 2400:
524		return DZ_B2400;
525	case 3600:
526		return DZ_B3600;
527	case 4800:
528		return DZ_B4800;
529	case 7200:
530		return DZ_B7200;
531	case 9600:
532		return DZ_B9600;
533	default:
534		return -1;
535	}
536}
537
538
539static void dz_reset(struct dz_port *dport)
540{
541	struct dz_mux *mux = dport->mux;
542
543	if (mux->initialised)
544		return;
545
546	dz_out(dport, DZ_CSR, DZ_CLR);
547	while (dz_in(dport, DZ_CSR) & DZ_CLR);
548	iob();
549
550	/* Enable scanning.  */
551	dz_out(dport, DZ_CSR, DZ_MSE);
552
553	mux->initialised = 1;
554}
555
556static void dz_set_termios(struct uart_port *uport, struct ktermios *termios,
557			   struct ktermios *old_termios)
558{
559	struct dz_port *dport = to_dport(uport);
560	unsigned long flags;
561	unsigned int cflag, baud;
562	int bflag;
563
564	cflag = dport->port.line;
565
566	switch (termios->c_cflag & CSIZE) {
567	case CS5:
568		cflag |= DZ_CS5;
569		break;
570	case CS6:
571		cflag |= DZ_CS6;
572		break;
573	case CS7:
574		cflag |= DZ_CS7;
575		break;
576	case CS8:
577	default:
578		cflag |= DZ_CS8;
579	}
580
581	if (termios->c_cflag & CSTOPB)
582		cflag |= DZ_CSTOPB;
583	if (termios->c_cflag & PARENB)
584		cflag |= DZ_PARENB;
585	if (termios->c_cflag & PARODD)
586		cflag |= DZ_PARODD;
587
588	baud = uart_get_baud_rate(uport, termios, old_termios, 50, 9600);
589	bflag = dz_encode_baud_rate(baud);
590	if (bflag < 0)	{			/* Try to keep unchanged.  */
591		baud = uart_get_baud_rate(uport, old_termios, NULL, 50, 9600);
592		bflag = dz_encode_baud_rate(baud);
593		if (bflag < 0)	{		/* Resort to 9600.  */
594			baud = 9600;
595			bflag = DZ_B9600;
596		}
597		tty_termios_encode_baud_rate(termios, baud, baud);
598	}
599	cflag |= bflag;
600
601	if (termios->c_cflag & CREAD)
602		cflag |= DZ_RXENAB;
603
604	spin_lock_irqsave(&dport->port.lock, flags);
605
606	uart_update_timeout(uport, termios->c_cflag, baud);
607
608	dz_out(dport, DZ_LPR, cflag);
609	dport->cflag = cflag;
610
611	/* setup accept flag */
612	dport->port.read_status_mask = DZ_OERR;
613	if (termios->c_iflag & INPCK)
614		dport->port.read_status_mask |= DZ_FERR | DZ_PERR;
615	if (termios->c_iflag & (BRKINT | PARMRK))
616		dport->port.read_status_mask |= DZ_BREAK;
617
618	/* characters to ignore */
619	uport->ignore_status_mask = 0;
620	if ((termios->c_iflag & (IGNPAR | IGNBRK)) == (IGNPAR | IGNBRK))
621		dport->port.ignore_status_mask |= DZ_OERR;
622	if (termios->c_iflag & IGNPAR)
623		dport->port.ignore_status_mask |= DZ_FERR | DZ_PERR;
624	if (termios->c_iflag & IGNBRK)
625		dport->port.ignore_status_mask |= DZ_BREAK;
626
627	spin_unlock_irqrestore(&dport->port.lock, flags);
628}
629
630/*
631 * Hack alert!
632 * Required solely so that the initial PROM-based console
633 * works undisturbed in parallel with this one.
634 */
635static void dz_pm(struct uart_port *uport, unsigned int state,
636		  unsigned int oldstate)
637{
638	struct dz_port *dport = to_dport(uport);
639	unsigned long flags;
640
641	spin_lock_irqsave(&dport->port.lock, flags);
642	if (state < 3)
643		dz_start_tx(&dport->port);
644	else
645		dz_stop_tx(&dport->port);
646	spin_unlock_irqrestore(&dport->port.lock, flags);
647}
648
649
650static const char *dz_type(struct uart_port *uport)
651{
652	return "DZ";
653}
654
655static void dz_release_port(struct uart_port *uport)
656{
657	struct dz_mux *mux = to_dport(uport)->mux;
658	int map_guard;
659
660	iounmap(uport->membase);
661	uport->membase = NULL;
662
663	map_guard = atomic_add_return(-1, &mux->map_guard);
664	if (!map_guard)
665		release_mem_region(uport->mapbase, dec_kn_slot_size);
666}
667
668static int dz_map_port(struct uart_port *uport)
669{
670	if (!uport->membase)
671		uport->membase = ioremap_nocache(uport->mapbase,
672						 dec_kn_slot_size);
673	if (!uport->membase) {
674		printk(KERN_ERR "dz: Cannot map MMIO\n");
675		return -ENOMEM;
676	}
677	return 0;
678}
679
680static int dz_request_port(struct uart_port *uport)
681{
682	struct dz_mux *mux = to_dport(uport)->mux;
683	int map_guard;
684	int ret;
685
686	map_guard = atomic_add_return(1, &mux->map_guard);
687	if (map_guard == 1) {
688		if (!request_mem_region(uport->mapbase, dec_kn_slot_size,
689					"dz")) {
690			atomic_add(-1, &mux->map_guard);
691			printk(KERN_ERR
692			       "dz: Unable to reserve MMIO resource\n");
693			return -EBUSY;
694		}
695	}
696	ret = dz_map_port(uport);
697	if (ret) {
698		map_guard = atomic_add_return(-1, &mux->map_guard);
699		if (!map_guard)
700			release_mem_region(uport->mapbase, dec_kn_slot_size);
701		return ret;
702	}
703	return 0;
704}
705
706static void dz_config_port(struct uart_port *uport, int flags)
707{
708	struct dz_port *dport = to_dport(uport);
709
710	if (flags & UART_CONFIG_TYPE) {
711		if (dz_request_port(uport))
712			return;
713
714		uport->type = PORT_DZ;
715
716		dz_reset(dport);
717	}
718}
719
720/*
721 * Verify the new serial_struct (for TIOCSSERIAL).
722 */
723static int dz_verify_port(struct uart_port *uport, struct serial_struct *ser)
724{
725	int ret = 0;
726
727	if (ser->type != PORT_UNKNOWN && ser->type != PORT_DZ)
728		ret = -EINVAL;
729	if (ser->irq != uport->irq)
730		ret = -EINVAL;
731	return ret;
732}
733
734static struct uart_ops dz_ops = {
735	.tx_empty	= dz_tx_empty,
736	.get_mctrl	= dz_get_mctrl,
737	.set_mctrl	= dz_set_mctrl,
738	.stop_tx	= dz_stop_tx,
739	.start_tx	= dz_start_tx,
740	.stop_rx	= dz_stop_rx,
741	.enable_ms	= dz_enable_ms,
742	.break_ctl	= dz_break_ctl,
743	.startup	= dz_startup,
744	.shutdown	= dz_shutdown,
745	.set_termios	= dz_set_termios,
746	.pm		= dz_pm,
747	.type		= dz_type,
748	.release_port	= dz_release_port,
749	.request_port	= dz_request_port,
750	.config_port	= dz_config_port,
751	.verify_port	= dz_verify_port,
752};
753
754static void __init dz_init_ports(void)
755{
756	static int first = 1;
757	unsigned long base;
758	int line;
759
760	if (!first)
761		return;
762	first = 0;
763
764	if (mips_machtype == MACH_DS23100 || mips_machtype == MACH_DS5100)
765		base = dec_kn_slot_base + KN01_DZ11;
766	else
767		base = dec_kn_slot_base + KN02_DZ11;
768
769	for (line = 0; line < DZ_NB_PORT; line++) {
770		struct dz_port *dport = &dz_mux.dport[line];
771		struct uart_port *uport = &dport->port;
772
773		dport->mux	= &dz_mux;
774
775		uport->irq	= dec_interrupt[DEC_IRQ_DZ11];
776		uport->fifosize	= 1;
777		uport->iotype	= UPIO_MEM;
778		uport->flags	= UPF_BOOT_AUTOCONF;
779		uport->ops	= &dz_ops;
780		uport->line	= line;
781		uport->mapbase	= base;
782	}
783}
784
785#ifdef CONFIG_SERIAL_DZ_CONSOLE
786/*
787 * -------------------------------------------------------------------
788 * dz_console_putchar() -- transmit a character
789 *
790 * Polled transmission.  This is tricky.  We need to mask transmit
791 * interrupts so that they do not interfere, enable the transmitter
792 * for the line requested and then wait till the transmit scanner
793 * requests data for this line.  But it may request data for another
794 * line first, in which case we have to disable its transmitter and
795 * repeat waiting till our line pops up.  Only then the character may
796 * be transmitted.  Finally, the state of the transmitter mask is
797 * restored.  Welcome to the world of PDP-11!
798 * -------------------------------------------------------------------
799 */
800static void dz_console_putchar(struct uart_port *uport, int ch)
801{
802	struct dz_port *dport = to_dport(uport);
803	unsigned long flags;
804	unsigned short csr, tcr, trdy, mask;
805	int loops = 10000;
806
807	spin_lock_irqsave(&dport->port.lock, flags);
808	csr = dz_in(dport, DZ_CSR);
809	dz_out(dport, DZ_CSR, csr & ~DZ_TIE);
810	tcr = dz_in(dport, DZ_TCR);
811	tcr |= 1 << dport->port.line;
812	mask = tcr;
813	dz_out(dport, DZ_TCR, mask);
814	iob();
815	spin_unlock_irqrestore(&dport->port.lock, flags);
816
817	do {
818		trdy = dz_in(dport, DZ_CSR);
819		if (!(trdy & DZ_TRDY))
820			continue;
821		trdy = (trdy & DZ_TLINE) >> 8;
822		if (trdy == dport->port.line)
823			break;
824		mask &= ~(1 << trdy);
825		dz_out(dport, DZ_TCR, mask);
826		iob();
827		udelay(2);
828	} while (--loops);
829
830	if (loops)				/* Cannot send otherwise. */
831		dz_out(dport, DZ_TDR, ch);
832
833	dz_out(dport, DZ_TCR, tcr);
834	dz_out(dport, DZ_CSR, csr);
835}
836
837/*
838 * -------------------------------------------------------------------
839 * dz_console_print ()
840 *
841 * dz_console_print is registered for printk.
842 * The console must be locked when we get here.
843 * -------------------------------------------------------------------
844 */
845static void dz_console_print(struct console *co,
846			     const char *str,
847			     unsigned int count)
848{
849	struct dz_port *dport = &dz_mux.dport[co->index];
850#ifdef DEBUG_DZ
851	prom_printf((char *) str);
852#endif
853	uart_console_write(&dport->port, str, count, dz_console_putchar);
854}
855
856static int __init dz_console_setup(struct console *co, char *options)
857{
858	struct dz_port *dport = &dz_mux.dport[co->index];
859	struct uart_port *uport = &dport->port;
860	int baud = 9600;
861	int bits = 8;
862	int parity = 'n';
863	int flow = 'n';
864	int ret;
865
866	ret = dz_map_port(uport);
867	if (ret)
868		return ret;
869
870	spin_lock_init(&dport->port.lock);	/* For dz_pm().  */
871
872	dz_reset(dport);
873	dz_pm(uport, 0, -1);
874
875	if (options)
876		uart_parse_options(options, &baud, &parity, &bits, &flow);
877
878	return uart_set_options(&dport->port, co, baud, parity, bits, flow);
879}
880
881static struct uart_driver dz_reg;
882static struct console dz_console = {
883	.name	= "ttyS",
884	.write	= dz_console_print,
885	.device	= uart_console_device,
886	.setup	= dz_console_setup,
887	.flags	= CON_PRINTBUFFER,
888	.index	= -1,
889	.data	= &dz_reg,
890};
891
892static int __init dz_serial_console_init(void)
893{
894	if (!IOASIC) {
895		dz_init_ports();
896		register_console(&dz_console);
897		return 0;
898	} else
899		return -ENXIO;
900}
901
902console_initcall(dz_serial_console_init);
903
904#define SERIAL_DZ_CONSOLE	&dz_console
905#else
906#define SERIAL_DZ_CONSOLE	NULL
907#endif /* CONFIG_SERIAL_DZ_CONSOLE */
908
909static struct uart_driver dz_reg = {
910	.owner			= THIS_MODULE,
911	.driver_name		= "serial",
912	.dev_name		= "ttyS",
913	.major			= TTY_MAJOR,
914	.minor			= 64,
915	.nr			= DZ_NB_PORT,
916	.cons			= SERIAL_DZ_CONSOLE,
917};
918
919static int __init dz_init(void)
920{
921	int ret, i;
922
923	if (IOASIC)
924		return -ENXIO;
925
926	printk("%s%s\n", dz_name, dz_version);
927
928	dz_init_ports();
929
930	ret = uart_register_driver(&dz_reg);
931	if (ret)
932		return ret;
933
934	for (i = 0; i < DZ_NB_PORT; i++)
935		uart_add_one_port(&dz_reg, &dz_mux.dport[i].port);
936
937	return 0;
938}
939
940module_init(dz_init);
941