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#include <linux/tty_flip.h>
51
52#include <linux/atomic.h>
53#include <asm/bootinfo.h>
54#include <asm/io.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
154/*
155 * ------------------------------------------------------------
156 *
157 * Here start the interrupt handling routines.  All of the following
158 * subroutines are declared as inline and are folded into
159 * dz_interrupt.  They were separated out for readability's sake.
160 *
161 * Note: dz_interrupt() is a "fast" interrupt, which means that it
162 * runs with interrupts turned off.  People who may want to modify
163 * dz_interrupt() should try to keep the interrupt handler as fast as
164 * possible.  After you are done making modifications, it is not a bad
165 * idea to do:
166 *
167 *	make drivers/serial/dz.s
168 *
169 * and look at the resulting assemble code in dz.s.
170 *
171 * ------------------------------------------------------------
172 */
173
174/*
175 * ------------------------------------------------------------
176 * receive_char ()
177 *
178 * This routine deals with inputs from any lines.
179 * ------------------------------------------------------------
180 */
181static inline void dz_receive_chars(struct dz_mux *mux)
182{
183	struct uart_port *uport;
184	struct dz_port *dport = &mux->dport[0];
185	struct uart_icount *icount;
186	int lines_rx[DZ_NB_PORT] = { [0 ... DZ_NB_PORT - 1] = 0 };
187	unsigned char ch, flag;
188	u16 status;
189	int i;
190
191	while ((status = dz_in(dport, DZ_RBUF)) & DZ_DVAL) {
192		dport = &mux->dport[LINE(status)];
193		uport = &dport->port;
194
195		ch = UCHAR(status);		/* grab the char */
196		flag = TTY_NORMAL;
197
198		icount = &uport->icount;
199		icount->rx++;
200
201		if (unlikely(status & (DZ_OERR | DZ_FERR | DZ_PERR))) {
202
203			/*
204			 * There is no separate BREAK status bit, so treat
205			 * null characters with framing errors as BREAKs;
206			 * normally, otherwise.  For this move the Framing
207			 * Error bit to a simulated BREAK bit.
208			 */
209			if (!ch) {
210				status |= (status & DZ_FERR) >>
211					  (ffs(DZ_FERR) - ffs(DZ_BREAK));
212				status &= ~DZ_FERR;
213			}
214
215			/* Handle SysRq/SAK & keep track of the statistics. */
216			if (status & DZ_BREAK) {
217				icount->brk++;
218				if (uart_handle_break(uport))
219					continue;
220			} else if (status & DZ_FERR)
221				icount->frame++;
222			else if (status & DZ_PERR)
223				icount->parity++;
224			if (status & DZ_OERR)
225				icount->overrun++;
226
227			status &= uport->read_status_mask;
228			if (status & DZ_BREAK)
229				flag = TTY_BREAK;
230			else if (status & DZ_FERR)
231				flag = TTY_FRAME;
232			else if (status & DZ_PERR)
233				flag = TTY_PARITY;
234
235		}
236
237		if (uart_handle_sysrq_char(uport, ch))
238			continue;
239
240		uart_insert_char(uport, status, DZ_OERR, ch, flag);
241		lines_rx[LINE(status)] = 1;
242	}
243	for (i = 0; i < DZ_NB_PORT; i++)
244		if (lines_rx[i])
245			tty_flip_buffer_push(&mux->dport[i].port.state->port);
246}
247
248/*
249 * ------------------------------------------------------------
250 * transmit_char ()
251 *
252 * This routine deals with outputs to any lines.
253 * ------------------------------------------------------------
254 */
255static inline void dz_transmit_chars(struct dz_mux *mux)
256{
257	struct dz_port *dport = &mux->dport[0];
258	struct circ_buf *xmit;
259	unsigned char tmp;
260	u16 status;
261
262	status = dz_in(dport, DZ_CSR);
263	dport = &mux->dport[LINE(status)];
264	xmit = &dport->port.state->xmit;
265
266	if (dport->port.x_char) {		/* XON/XOFF chars */
267		dz_out(dport, DZ_TDR, dport->port.x_char);
268		dport->port.icount.tx++;
269		dport->port.x_char = 0;
270		return;
271	}
272	/* If nothing to do or stopped or hardware stopped. */
273	if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {
274		spin_lock(&dport->port.lock);
275		dz_stop_tx(&dport->port);
276		spin_unlock(&dport->port.lock);
277		return;
278	}
279
280	/*
281	 * If something to do... (remember the dz has no output fifo,
282	 * so we go one char at a time) :-<
283	 */
284	tmp = xmit->buf[xmit->tail];
285	xmit->tail = (xmit->tail + 1) & (DZ_XMIT_SIZE - 1);
286	dz_out(dport, DZ_TDR, tmp);
287	dport->port.icount.tx++;
288
289	if (uart_circ_chars_pending(xmit) < DZ_WAKEUP_CHARS)
290		uart_write_wakeup(&dport->port);
291
292	/* Are we are done. */
293	if (uart_circ_empty(xmit)) {
294		spin_lock(&dport->port.lock);
295		dz_stop_tx(&dport->port);
296		spin_unlock(&dport->port.lock);
297	}
298}
299
300/*
301 * ------------------------------------------------------------
302 * check_modem_status()
303 *
304 * DS 3100 & 5100: Only valid for the MODEM line, duh!
305 * DS 5000/200: Valid for the MODEM and PRINTER line.
306 * ------------------------------------------------------------
307 */
308static inline void check_modem_status(struct dz_port *dport)
309{
310	/*
311	 * FIXME:
312	 * 1. No status change interrupt; use a timer.
313	 * 2. Handle the 3100/5000 as appropriate. --macro
314	 */
315	u16 status;
316
317	/* If not the modem line just return.  */
318	if (dport->port.line != DZ_MODEM)
319		return;
320
321	status = dz_in(dport, DZ_MSR);
322
323	/* it's easy, since DSR2 is the only bit in the register */
324	if (status)
325		dport->port.icount.dsr++;
326}
327
328/*
329 * ------------------------------------------------------------
330 * dz_interrupt ()
331 *
332 * this is the main interrupt routine for the DZ chip.
333 * It deals with the multiple ports.
334 * ------------------------------------------------------------
335 */
336static irqreturn_t dz_interrupt(int irq, void *dev_id)
337{
338	struct dz_mux *mux = dev_id;
339	struct dz_port *dport = &mux->dport[0];
340	u16 status;
341
342	/* get the reason why we just got an irq */
343	status = dz_in(dport, DZ_CSR);
344
345	if ((status & (DZ_RDONE | DZ_RIE)) == (DZ_RDONE | DZ_RIE))
346		dz_receive_chars(mux);
347
348	if ((status & (DZ_TRDY | DZ_TIE)) == (DZ_TRDY | DZ_TIE))
349		dz_transmit_chars(mux);
350
351	return IRQ_HANDLED;
352}
353
354/*
355 * -------------------------------------------------------------------
356 * Here ends the DZ interrupt routines.
357 * -------------------------------------------------------------------
358 */
359
360static unsigned int dz_get_mctrl(struct uart_port *uport)
361{
362	/*
363	 * FIXME: Handle the 3100/5000 as appropriate. --macro
364	 */
365	struct dz_port *dport = to_dport(uport);
366	unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
367
368	if (dport->port.line == DZ_MODEM) {
369		if (dz_in(dport, DZ_MSR) & DZ_MODEM_DSR)
370			mctrl &= ~TIOCM_DSR;
371	}
372
373	return mctrl;
374}
375
376static void dz_set_mctrl(struct uart_port *uport, unsigned int mctrl)
377{
378	/*
379	 * FIXME: Handle the 3100/5000 as appropriate. --macro
380	 */
381	struct dz_port *dport = to_dport(uport);
382	u16 tmp;
383
384	if (dport->port.line == DZ_MODEM) {
385		tmp = dz_in(dport, DZ_TCR);
386		if (mctrl & TIOCM_DTR)
387			tmp &= ~DZ_MODEM_DTR;
388		else
389			tmp |= DZ_MODEM_DTR;
390		dz_out(dport, DZ_TCR, tmp);
391	}
392}
393
394/*
395 * -------------------------------------------------------------------
396 * startup ()
397 *
398 * various initialization tasks
399 * -------------------------------------------------------------------
400 */
401static int dz_startup(struct uart_port *uport)
402{
403	struct dz_port *dport = to_dport(uport);
404	struct dz_mux *mux = dport->mux;
405	unsigned long flags;
406	int irq_guard;
407	int ret;
408	u16 tmp;
409
410	irq_guard = atomic_add_return(1, &mux->irq_guard);
411	if (irq_guard != 1)
412		return 0;
413
414	ret = request_irq(dport->port.irq, dz_interrupt,
415			  IRQF_SHARED, "dz", mux);
416	if (ret) {
417		atomic_add(-1, &mux->irq_guard);
418		printk(KERN_ERR "dz: Cannot get IRQ %d!\n", dport->port.irq);
419		return ret;
420	}
421
422	spin_lock_irqsave(&dport->port.lock, flags);
423
424	/* Enable interrupts.  */
425	tmp = dz_in(dport, DZ_CSR);
426	tmp |= DZ_RIE | DZ_TIE;
427	dz_out(dport, DZ_CSR, tmp);
428
429	spin_unlock_irqrestore(&dport->port.lock, flags);
430
431	return 0;
432}
433
434/*
435 * -------------------------------------------------------------------
436 * shutdown ()
437 *
438 * This routine will shutdown a serial port; interrupts are disabled, and
439 * DTR is dropped if the hangup on close termio flag is on.
440 * -------------------------------------------------------------------
441 */
442static void dz_shutdown(struct uart_port *uport)
443{
444	struct dz_port *dport = to_dport(uport);
445	struct dz_mux *mux = dport->mux;
446	unsigned long flags;
447	int irq_guard;
448	u16 tmp;
449
450	spin_lock_irqsave(&dport->port.lock, flags);
451	dz_stop_tx(&dport->port);
452	spin_unlock_irqrestore(&dport->port.lock, flags);
453
454	irq_guard = atomic_add_return(-1, &mux->irq_guard);
455	if (!irq_guard) {
456		/* Disable interrupts.  */
457		tmp = dz_in(dport, DZ_CSR);
458		tmp &= ~(DZ_RIE | DZ_TIE);
459		dz_out(dport, DZ_CSR, tmp);
460
461		free_irq(dport->port.irq, mux);
462	}
463}
464
465/*
466 * -------------------------------------------------------------------
467 * dz_tx_empty() -- get the transmitter empty status
468 *
469 * Purpose: Let user call ioctl() to get info when the UART physically
470 *          is emptied.  On bus types like RS485, the transmitter must
471 *          release the bus after transmitting. This must be done when
472 *          the transmit shift register is empty, not be done when the
473 *          transmit holding register is empty.  This functionality
474 *          allows an RS485 driver to be written in user space.
475 * -------------------------------------------------------------------
476 */
477static unsigned int dz_tx_empty(struct uart_port *uport)
478{
479	struct dz_port *dport = to_dport(uport);
480	unsigned short tmp, mask = 1 << dport->port.line;
481
482	tmp = dz_in(dport, DZ_TCR);
483	tmp &= mask;
484
485	return tmp ? 0 : TIOCSER_TEMT;
486}
487
488static void dz_break_ctl(struct uart_port *uport, int break_state)
489{
490	/*
491	 * FIXME: Can't access BREAK bits in TDR easily;
492	 * reuse the code for polled TX. --macro
493	 */
494	struct dz_port *dport = to_dport(uport);
495	unsigned long flags;
496	unsigned short tmp, mask = 1 << dport->port.line;
497
498	spin_lock_irqsave(&uport->lock, flags);
499	tmp = dz_in(dport, DZ_TCR);
500	if (break_state)
501		tmp |= mask;
502	else
503		tmp &= ~mask;
504	dz_out(dport, DZ_TCR, tmp);
505	spin_unlock_irqrestore(&uport->lock, flags);
506}
507
508static int dz_encode_baud_rate(unsigned int baud)
509{
510	switch (baud) {
511	case 50:
512		return DZ_B50;
513	case 75:
514		return DZ_B75;
515	case 110:
516		return DZ_B110;
517	case 134:
518		return DZ_B134;
519	case 150:
520		return DZ_B150;
521	case 300:
522		return DZ_B300;
523	case 600:
524		return DZ_B600;
525	case 1200:
526		return DZ_B1200;
527	case 1800:
528		return DZ_B1800;
529	case 2000:
530		return DZ_B2000;
531	case 2400:
532		return DZ_B2400;
533	case 3600:
534		return DZ_B3600;
535	case 4800:
536		return DZ_B4800;
537	case 7200:
538		return DZ_B7200;
539	case 9600:
540		return DZ_B9600;
541	default:
542		return -1;
543	}
544}
545
546
547static void dz_reset(struct dz_port *dport)
548{
549	struct dz_mux *mux = dport->mux;
550
551	if (mux->initialised)
552		return;
553
554	dz_out(dport, DZ_CSR, DZ_CLR);
555	while (dz_in(dport, DZ_CSR) & DZ_CLR);
556	iob();
557
558	/* Enable scanning.  */
559	dz_out(dport, DZ_CSR, DZ_MSE);
560
561	mux->initialised = 1;
562}
563
564static void dz_set_termios(struct uart_port *uport, struct ktermios *termios,
565			   struct ktermios *old_termios)
566{
567	struct dz_port *dport = to_dport(uport);
568	unsigned long flags;
569	unsigned int cflag, baud;
570	int bflag;
571
572	cflag = dport->port.line;
573
574	switch (termios->c_cflag & CSIZE) {
575	case CS5:
576		cflag |= DZ_CS5;
577		break;
578	case CS6:
579		cflag |= DZ_CS6;
580		break;
581	case CS7:
582		cflag |= DZ_CS7;
583		break;
584	case CS8:
585	default:
586		cflag |= DZ_CS8;
587	}
588
589	if (termios->c_cflag & CSTOPB)
590		cflag |= DZ_CSTOPB;
591	if (termios->c_cflag & PARENB)
592		cflag |= DZ_PARENB;
593	if (termios->c_cflag & PARODD)
594		cflag |= DZ_PARODD;
595
596	baud = uart_get_baud_rate(uport, termios, old_termios, 50, 9600);
597	bflag = dz_encode_baud_rate(baud);
598	if (bflag < 0)	{			/* Try to keep unchanged.  */
599		baud = uart_get_baud_rate(uport, old_termios, NULL, 50, 9600);
600		bflag = dz_encode_baud_rate(baud);
601		if (bflag < 0)	{		/* Resort to 9600.  */
602			baud = 9600;
603			bflag = DZ_B9600;
604		}
605		tty_termios_encode_baud_rate(termios, baud, baud);
606	}
607	cflag |= bflag;
608
609	if (termios->c_cflag & CREAD)
610		cflag |= DZ_RXENAB;
611
612	spin_lock_irqsave(&dport->port.lock, flags);
613
614	uart_update_timeout(uport, termios->c_cflag, baud);
615
616	dz_out(dport, DZ_LPR, cflag);
617	dport->cflag = cflag;
618
619	/* setup accept flag */
620	dport->port.read_status_mask = DZ_OERR;
621	if (termios->c_iflag & INPCK)
622		dport->port.read_status_mask |= DZ_FERR | DZ_PERR;
623	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
624		dport->port.read_status_mask |= DZ_BREAK;
625
626	/* characters to ignore */
627	uport->ignore_status_mask = 0;
628	if ((termios->c_iflag & (IGNPAR | IGNBRK)) == (IGNPAR | IGNBRK))
629		dport->port.ignore_status_mask |= DZ_OERR;
630	if (termios->c_iflag & IGNPAR)
631		dport->port.ignore_status_mask |= DZ_FERR | DZ_PERR;
632	if (termios->c_iflag & IGNBRK)
633		dport->port.ignore_status_mask |= DZ_BREAK;
634
635	spin_unlock_irqrestore(&dport->port.lock, flags);
636}
637
638/*
639 * Hack alert!
640 * Required solely so that the initial PROM-based console
641 * works undisturbed in parallel with this one.
642 */
643static void dz_pm(struct uart_port *uport, unsigned int state,
644		  unsigned int oldstate)
645{
646	struct dz_port *dport = to_dport(uport);
647	unsigned long flags;
648
649	spin_lock_irqsave(&dport->port.lock, flags);
650	if (state < 3)
651		dz_start_tx(&dport->port);
652	else
653		dz_stop_tx(&dport->port);
654	spin_unlock_irqrestore(&dport->port.lock, flags);
655}
656
657
658static const char *dz_type(struct uart_port *uport)
659{
660	return "DZ";
661}
662
663static void dz_release_port(struct uart_port *uport)
664{
665	struct dz_mux *mux = to_dport(uport)->mux;
666	int map_guard;
667
668	iounmap(uport->membase);
669	uport->membase = NULL;
670
671	map_guard = atomic_add_return(-1, &mux->map_guard);
672	if (!map_guard)
673		release_mem_region(uport->mapbase, dec_kn_slot_size);
674}
675
676static int dz_map_port(struct uart_port *uport)
677{
678	if (!uport->membase)
679		uport->membase = ioremap_nocache(uport->mapbase,
680						 dec_kn_slot_size);
681	if (!uport->membase) {
682		printk(KERN_ERR "dz: Cannot map MMIO\n");
683		return -ENOMEM;
684	}
685	return 0;
686}
687
688static int dz_request_port(struct uart_port *uport)
689{
690	struct dz_mux *mux = to_dport(uport)->mux;
691	int map_guard;
692	int ret;
693
694	map_guard = atomic_add_return(1, &mux->map_guard);
695	if (map_guard == 1) {
696		if (!request_mem_region(uport->mapbase, dec_kn_slot_size,
697					"dz")) {
698			atomic_add(-1, &mux->map_guard);
699			printk(KERN_ERR
700			       "dz: Unable to reserve MMIO resource\n");
701			return -EBUSY;
702		}
703	}
704	ret = dz_map_port(uport);
705	if (ret) {
706		map_guard = atomic_add_return(-1, &mux->map_guard);
707		if (!map_guard)
708			release_mem_region(uport->mapbase, dec_kn_slot_size);
709		return ret;
710	}
711	return 0;
712}
713
714static void dz_config_port(struct uart_port *uport, int flags)
715{
716	struct dz_port *dport = to_dport(uport);
717
718	if (flags & UART_CONFIG_TYPE) {
719		if (dz_request_port(uport))
720			return;
721
722		uport->type = PORT_DZ;
723
724		dz_reset(dport);
725	}
726}
727
728/*
729 * Verify the new serial_struct (for TIOCSSERIAL).
730 */
731static int dz_verify_port(struct uart_port *uport, struct serial_struct *ser)
732{
733	int ret = 0;
734
735	if (ser->type != PORT_UNKNOWN && ser->type != PORT_DZ)
736		ret = -EINVAL;
737	if (ser->irq != uport->irq)
738		ret = -EINVAL;
739	return ret;
740}
741
742static struct uart_ops dz_ops = {
743	.tx_empty	= dz_tx_empty,
744	.get_mctrl	= dz_get_mctrl,
745	.set_mctrl	= dz_set_mctrl,
746	.stop_tx	= dz_stop_tx,
747	.start_tx	= dz_start_tx,
748	.stop_rx	= dz_stop_rx,
749	.break_ctl	= dz_break_ctl,
750	.startup	= dz_startup,
751	.shutdown	= dz_shutdown,
752	.set_termios	= dz_set_termios,
753	.pm		= dz_pm,
754	.type		= dz_type,
755	.release_port	= dz_release_port,
756	.request_port	= dz_request_port,
757	.config_port	= dz_config_port,
758	.verify_port	= dz_verify_port,
759};
760
761static void __init dz_init_ports(void)
762{
763	static int first = 1;
764	unsigned long base;
765	int line;
766
767	if (!first)
768		return;
769	first = 0;
770
771	if (mips_machtype == MACH_DS23100 || mips_machtype == MACH_DS5100)
772		base = dec_kn_slot_base + KN01_DZ11;
773	else
774		base = dec_kn_slot_base + KN02_DZ11;
775
776	for (line = 0; line < DZ_NB_PORT; line++) {
777		struct dz_port *dport = &dz_mux.dport[line];
778		struct uart_port *uport = &dport->port;
779
780		dport->mux	= &dz_mux;
781
782		uport->irq	= dec_interrupt[DEC_IRQ_DZ11];
783		uport->fifosize	= 1;
784		uport->iotype	= UPIO_MEM;
785		uport->flags	= UPF_BOOT_AUTOCONF;
786		uport->ops	= &dz_ops;
787		uport->line	= line;
788		uport->mapbase	= base;
789	}
790}
791
792#ifdef CONFIG_SERIAL_DZ_CONSOLE
793/*
794 * -------------------------------------------------------------------
795 * dz_console_putchar() -- transmit a character
796 *
797 * Polled transmission.  This is tricky.  We need to mask transmit
798 * interrupts so that they do not interfere, enable the transmitter
799 * for the line requested and then wait till the transmit scanner
800 * requests data for this line.  But it may request data for another
801 * line first, in which case we have to disable its transmitter and
802 * repeat waiting till our line pops up.  Only then the character may
803 * be transmitted.  Finally, the state of the transmitter mask is
804 * restored.  Welcome to the world of PDP-11!
805 * -------------------------------------------------------------------
806 */
807static void dz_console_putchar(struct uart_port *uport, int ch)
808{
809	struct dz_port *dport = to_dport(uport);
810	unsigned long flags;
811	unsigned short csr, tcr, trdy, mask;
812	int loops = 10000;
813
814	spin_lock_irqsave(&dport->port.lock, flags);
815	csr = dz_in(dport, DZ_CSR);
816	dz_out(dport, DZ_CSR, csr & ~DZ_TIE);
817	tcr = dz_in(dport, DZ_TCR);
818	tcr |= 1 << dport->port.line;
819	mask = tcr;
820	dz_out(dport, DZ_TCR, mask);
821	iob();
822	spin_unlock_irqrestore(&dport->port.lock, flags);
823
824	do {
825		trdy = dz_in(dport, DZ_CSR);
826		if (!(trdy & DZ_TRDY))
827			continue;
828		trdy = (trdy & DZ_TLINE) >> 8;
829		if (trdy == dport->port.line)
830			break;
831		mask &= ~(1 << trdy);
832		dz_out(dport, DZ_TCR, mask);
833		iob();
834		udelay(2);
835	} while (--loops);
836
837	if (loops)				/* Cannot send otherwise. */
838		dz_out(dport, DZ_TDR, ch);
839
840	dz_out(dport, DZ_TCR, tcr);
841	dz_out(dport, DZ_CSR, csr);
842}
843
844/*
845 * -------------------------------------------------------------------
846 * dz_console_print ()
847 *
848 * dz_console_print is registered for printk.
849 * The console must be locked when we get here.
850 * -------------------------------------------------------------------
851 */
852static void dz_console_print(struct console *co,
853			     const char *str,
854			     unsigned int count)
855{
856	struct dz_port *dport = &dz_mux.dport[co->index];
857#ifdef DEBUG_DZ
858	prom_printf((char *) str);
859#endif
860	uart_console_write(&dport->port, str, count, dz_console_putchar);
861}
862
863static int __init dz_console_setup(struct console *co, char *options)
864{
865	struct dz_port *dport = &dz_mux.dport[co->index];
866	struct uart_port *uport = &dport->port;
867	int baud = 9600;
868	int bits = 8;
869	int parity = 'n';
870	int flow = 'n';
871	int ret;
872
873	ret = dz_map_port(uport);
874	if (ret)
875		return ret;
876
877	spin_lock_init(&dport->port.lock);	/* For dz_pm().  */
878
879	dz_reset(dport);
880	dz_pm(uport, 0, -1);
881
882	if (options)
883		uart_parse_options(options, &baud, &parity, &bits, &flow);
884
885	return uart_set_options(&dport->port, co, baud, parity, bits, flow);
886}
887
888static struct uart_driver dz_reg;
889static struct console dz_console = {
890	.name	= "ttyS",
891	.write	= dz_console_print,
892	.device	= uart_console_device,
893	.setup	= dz_console_setup,
894	.flags	= CON_PRINTBUFFER,
895	.index	= -1,
896	.data	= &dz_reg,
897};
898
899static int __init dz_serial_console_init(void)
900{
901	if (!IOASIC) {
902		dz_init_ports();
903		register_console(&dz_console);
904		return 0;
905	} else
906		return -ENXIO;
907}
908
909console_initcall(dz_serial_console_init);
910
911#define SERIAL_DZ_CONSOLE	&dz_console
912#else
913#define SERIAL_DZ_CONSOLE	NULL
914#endif /* CONFIG_SERIAL_DZ_CONSOLE */
915
916static struct uart_driver dz_reg = {
917	.owner			= THIS_MODULE,
918	.driver_name		= "serial",
919	.dev_name		= "ttyS",
920	.major			= TTY_MAJOR,
921	.minor			= 64,
922	.nr			= DZ_NB_PORT,
923	.cons			= SERIAL_DZ_CONSOLE,
924};
925
926static int __init dz_init(void)
927{
928	int ret, i;
929
930	if (IOASIC)
931		return -ENXIO;
932
933	printk("%s%s\n", dz_name, dz_version);
934
935	dz_init_ports();
936
937	ret = uart_register_driver(&dz_reg);
938	if (ret)
939		return ret;
940
941	for (i = 0; i < DZ_NB_PORT; i++)
942		uart_add_one_port(&dz_reg, &dz_mux.dport[i].port);
943
944	return 0;
945}
946
947module_init(dz_init);
948