xref: /openbmc/linux/drivers/tty/serial/pmac_zilog.c (revision 275876e2)
1 /*
2  * Driver for PowerMac Z85c30 based ESCC cell found in the
3  * "macio" ASICs of various PowerMac models
4  *
5  * Copyright (C) 2003 Ben. Herrenschmidt (benh@kernel.crashing.org)
6  *
7  * Derived from drivers/macintosh/macserial.c by Paul Mackerras
8  * and drivers/serial/sunzilog.c by David S. Miller
9  *
10  * Hrm... actually, I ripped most of sunzilog (Thanks David !) and
11  * adapted special tweaks needed for us. I don't think it's worth
12  * merging back those though. The DMA code still has to get in
13  * and once done, I expect that driver to remain fairly stable in
14  * the long term, unless we change the driver model again...
15  *
16  * This program is free software; you can redistribute it and/or modify
17  * it under the terms of the GNU General Public License as published by
18  * the Free Software Foundation; either version 2 of the License, or
19  * (at your option) any later version.
20  *
21  * This program is distributed in the hope that it will be useful,
22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
24  * GNU General Public License for more details.
25  *
26  * You should have received a copy of the GNU General Public License
27  * along with this program; if not, write to the Free Software
28  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
29  *
30  * 2004-08-06 Harald Welte <laforge@gnumonks.org>
31  *	- Enable BREAK interrupt
32  *	- Add support for sysreq
33  *
34  * TODO:   - Add DMA support
35  *         - Defer port shutdown to a few seconds after close
36  *         - maybe put something right into uap->clk_divisor
37  */
38 
39 #undef DEBUG
40 #undef DEBUG_HARD
41 #undef USE_CTRL_O_SYSRQ
42 
43 #include <linux/module.h>
44 #include <linux/tty.h>
45 
46 #include <linux/tty_flip.h>
47 #include <linux/major.h>
48 #include <linux/string.h>
49 #include <linux/fcntl.h>
50 #include <linux/mm.h>
51 #include <linux/kernel.h>
52 #include <linux/delay.h>
53 #include <linux/init.h>
54 #include <linux/console.h>
55 #include <linux/adb.h>
56 #include <linux/pmu.h>
57 #include <linux/bitops.h>
58 #include <linux/sysrq.h>
59 #include <linux/mutex.h>
60 #include <linux/of_address.h>
61 #include <linux/of_irq.h>
62 #include <asm/sections.h>
63 #include <asm/io.h>
64 #include <asm/irq.h>
65 
66 #ifdef CONFIG_PPC_PMAC
67 #include <asm/prom.h>
68 #include <asm/machdep.h>
69 #include <asm/pmac_feature.h>
70 #include <asm/dbdma.h>
71 #include <asm/macio.h>
72 #else
73 #include <linux/platform_device.h>
74 #define of_machine_is_compatible(x) (0)
75 #endif
76 
77 #if defined (CONFIG_SERIAL_PMACZILOG_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
78 #define SUPPORT_SYSRQ
79 #endif
80 
81 #include <linux/serial.h>
82 #include <linux/serial_core.h>
83 
84 #include "pmac_zilog.h"
85 
86 /* Not yet implemented */
87 #undef HAS_DBDMA
88 
89 static char version[] __initdata = "pmac_zilog: 0.6 (Benjamin Herrenschmidt <benh@kernel.crashing.org>)";
90 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
91 MODULE_DESCRIPTION("Driver for the Mac and PowerMac serial ports.");
92 MODULE_LICENSE("GPL");
93 
94 #ifdef CONFIG_SERIAL_PMACZILOG_TTYS
95 #define PMACZILOG_MAJOR		TTY_MAJOR
96 #define PMACZILOG_MINOR		64
97 #define PMACZILOG_NAME		"ttyS"
98 #else
99 #define PMACZILOG_MAJOR		204
100 #define PMACZILOG_MINOR		192
101 #define PMACZILOG_NAME		"ttyPZ"
102 #endif
103 
104 #define pmz_debug(fmt, arg...)	pr_debug("ttyPZ%d: " fmt, uap->port.line, ## arg)
105 #define pmz_error(fmt, arg...)	pr_err("ttyPZ%d: " fmt, uap->port.line, ## arg)
106 #define pmz_info(fmt, arg...)	pr_info("ttyPZ%d: " fmt, uap->port.line, ## arg)
107 
108 /*
109  * For the sake of early serial console, we can do a pre-probe
110  * (optional) of the ports at rather early boot time.
111  */
112 static struct uart_pmac_port	pmz_ports[MAX_ZS_PORTS];
113 static int			pmz_ports_count;
114 
115 static struct uart_driver pmz_uart_reg = {
116 	.owner		=	THIS_MODULE,
117 	.driver_name	=	PMACZILOG_NAME,
118 	.dev_name	=	PMACZILOG_NAME,
119 	.major		=	PMACZILOG_MAJOR,
120 	.minor		=	PMACZILOG_MINOR,
121 };
122 
123 
124 /*
125  * Load all registers to reprogram the port
126  * This function must only be called when the TX is not busy.  The UART
127  * port lock must be held and local interrupts disabled.
128  */
129 static void pmz_load_zsregs(struct uart_pmac_port *uap, u8 *regs)
130 {
131 	int i;
132 
133 	/* Let pending transmits finish.  */
134 	for (i = 0; i < 1000; i++) {
135 		unsigned char stat = read_zsreg(uap, R1);
136 		if (stat & ALL_SNT)
137 			break;
138 		udelay(100);
139 	}
140 
141 	ZS_CLEARERR(uap);
142 	zssync(uap);
143 	ZS_CLEARFIFO(uap);
144 	zssync(uap);
145 	ZS_CLEARERR(uap);
146 
147 	/* Disable all interrupts.  */
148 	write_zsreg(uap, R1,
149 		    regs[R1] & ~(RxINT_MASK | TxINT_ENAB | EXT_INT_ENAB));
150 
151 	/* Set parity, sync config, stop bits, and clock divisor.  */
152 	write_zsreg(uap, R4, regs[R4]);
153 
154 	/* Set misc. TX/RX control bits.  */
155 	write_zsreg(uap, R10, regs[R10]);
156 
157 	/* Set TX/RX controls sans the enable bits.  */
158 	write_zsreg(uap, R3, regs[R3] & ~RxENABLE);
159 	write_zsreg(uap, R5, regs[R5] & ~TxENABLE);
160 
161 	/* now set R7 "prime" on ESCC */
162 	write_zsreg(uap, R15, regs[R15] | EN85C30);
163 	write_zsreg(uap, R7, regs[R7P]);
164 
165 	/* make sure we use R7 "non-prime" on ESCC */
166 	write_zsreg(uap, R15, regs[R15] & ~EN85C30);
167 
168 	/* Synchronous mode config.  */
169 	write_zsreg(uap, R6, regs[R6]);
170 	write_zsreg(uap, R7, regs[R7]);
171 
172 	/* Disable baud generator.  */
173 	write_zsreg(uap, R14, regs[R14] & ~BRENAB);
174 
175 	/* Clock mode control.  */
176 	write_zsreg(uap, R11, regs[R11]);
177 
178 	/* Lower and upper byte of baud rate generator divisor.  */
179 	write_zsreg(uap, R12, regs[R12]);
180 	write_zsreg(uap, R13, regs[R13]);
181 
182 	/* Now rewrite R14, with BRENAB (if set).  */
183 	write_zsreg(uap, R14, regs[R14]);
184 
185 	/* Reset external status interrupts.  */
186 	write_zsreg(uap, R0, RES_EXT_INT);
187 	write_zsreg(uap, R0, RES_EXT_INT);
188 
189 	/* Rewrite R3/R5, this time without enables masked.  */
190 	write_zsreg(uap, R3, regs[R3]);
191 	write_zsreg(uap, R5, regs[R5]);
192 
193 	/* Rewrite R1, this time without IRQ enabled masked.  */
194 	write_zsreg(uap, R1, regs[R1]);
195 
196 	/* Enable interrupts */
197 	write_zsreg(uap, R9, regs[R9]);
198 }
199 
200 /*
201  * We do like sunzilog to avoid disrupting pending Tx
202  * Reprogram the Zilog channel HW registers with the copies found in the
203  * software state struct.  If the transmitter is busy, we defer this update
204  * until the next TX complete interrupt.  Else, we do it right now.
205  *
206  * The UART port lock must be held and local interrupts disabled.
207  */
208 static void pmz_maybe_update_regs(struct uart_pmac_port *uap)
209 {
210 	if (!ZS_REGS_HELD(uap)) {
211 		if (ZS_TX_ACTIVE(uap)) {
212 			uap->flags |= PMACZILOG_FLAG_REGS_HELD;
213 		} else {
214 			pmz_debug("pmz: maybe_update_regs: updating\n");
215 			pmz_load_zsregs(uap, uap->curregs);
216 		}
217 	}
218 }
219 
220 static void pmz_interrupt_control(struct uart_pmac_port *uap, int enable)
221 {
222 	if (enable) {
223 		uap->curregs[1] |= INT_ALL_Rx | TxINT_ENAB;
224 		if (!ZS_IS_EXTCLK(uap))
225 			uap->curregs[1] |= EXT_INT_ENAB;
226 	} else {
227 		uap->curregs[1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
228 	}
229 	write_zsreg(uap, R1, uap->curregs[1]);
230 }
231 
232 static bool pmz_receive_chars(struct uart_pmac_port *uap)
233 {
234 	struct tty_port *port;
235 	unsigned char ch, r1, drop, error, flag;
236 	int loops = 0;
237 
238 	/* Sanity check, make sure the old bug is no longer happening */
239 	if (uap->port.state == NULL) {
240 		WARN_ON(1);
241 		(void)read_zsdata(uap);
242 		return false;
243 	}
244 	port = &uap->port.state->port;
245 
246 	while (1) {
247 		error = 0;
248 		drop = 0;
249 
250 		r1 = read_zsreg(uap, R1);
251 		ch = read_zsdata(uap);
252 
253 		if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR)) {
254 			write_zsreg(uap, R0, ERR_RES);
255 			zssync(uap);
256 		}
257 
258 		ch &= uap->parity_mask;
259 		if (ch == 0 && uap->flags & PMACZILOG_FLAG_BREAK) {
260 			uap->flags &= ~PMACZILOG_FLAG_BREAK;
261 		}
262 
263 #if defined(CONFIG_MAGIC_SYSRQ) && defined(CONFIG_SERIAL_CORE_CONSOLE)
264 #ifdef USE_CTRL_O_SYSRQ
265 		/* Handle the SysRq ^O Hack */
266 		if (ch == '\x0f') {
267 			uap->port.sysrq = jiffies + HZ*5;
268 			goto next_char;
269 		}
270 #endif /* USE_CTRL_O_SYSRQ */
271 		if (uap->port.sysrq) {
272 			int swallow;
273 			spin_unlock(&uap->port.lock);
274 			swallow = uart_handle_sysrq_char(&uap->port, ch);
275 			spin_lock(&uap->port.lock);
276 			if (swallow)
277 				goto next_char;
278 		}
279 #endif /* CONFIG_MAGIC_SYSRQ && CONFIG_SERIAL_CORE_CONSOLE */
280 
281 		/* A real serial line, record the character and status.  */
282 		if (drop)
283 			goto next_char;
284 
285 		flag = TTY_NORMAL;
286 		uap->port.icount.rx++;
287 
288 		if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR | BRK_ABRT)) {
289 			error = 1;
290 			if (r1 & BRK_ABRT) {
291 				pmz_debug("pmz: got break !\n");
292 				r1 &= ~(PAR_ERR | CRC_ERR);
293 				uap->port.icount.brk++;
294 				if (uart_handle_break(&uap->port))
295 					goto next_char;
296 			}
297 			else if (r1 & PAR_ERR)
298 				uap->port.icount.parity++;
299 			else if (r1 & CRC_ERR)
300 				uap->port.icount.frame++;
301 			if (r1 & Rx_OVR)
302 				uap->port.icount.overrun++;
303 			r1 &= uap->port.read_status_mask;
304 			if (r1 & BRK_ABRT)
305 				flag = TTY_BREAK;
306 			else if (r1 & PAR_ERR)
307 				flag = TTY_PARITY;
308 			else if (r1 & CRC_ERR)
309 				flag = TTY_FRAME;
310 		}
311 
312 		if (uap->port.ignore_status_mask == 0xff ||
313 		    (r1 & uap->port.ignore_status_mask) == 0) {
314 			tty_insert_flip_char(port, ch, flag);
315 		}
316 		if (r1 & Rx_OVR)
317 			tty_insert_flip_char(port, 0, TTY_OVERRUN);
318 	next_char:
319 		/* We can get stuck in an infinite loop getting char 0 when the
320 		 * line is in a wrong HW state, we break that here.
321 		 * When that happens, I disable the receive side of the driver.
322 		 * Note that what I've been experiencing is a real irq loop where
323 		 * I'm getting flooded regardless of the actual port speed.
324 		 * Something strange is going on with the HW
325 		 */
326 		if ((++loops) > 1000)
327 			goto flood;
328 		ch = read_zsreg(uap, R0);
329 		if (!(ch & Rx_CH_AV))
330 			break;
331 	}
332 
333 	return true;
334  flood:
335 	pmz_interrupt_control(uap, 0);
336 	pmz_error("pmz: rx irq flood !\n");
337 	return true;
338 }
339 
340 static void pmz_status_handle(struct uart_pmac_port *uap)
341 {
342 	unsigned char status;
343 
344 	status = read_zsreg(uap, R0);
345 	write_zsreg(uap, R0, RES_EXT_INT);
346 	zssync(uap);
347 
348 	if (ZS_IS_OPEN(uap) && ZS_WANTS_MODEM_STATUS(uap)) {
349 		if (status & SYNC_HUNT)
350 			uap->port.icount.dsr++;
351 
352 		/* The Zilog just gives us an interrupt when DCD/CTS/etc. change.
353 		 * But it does not tell us which bit has changed, we have to keep
354 		 * track of this ourselves.
355 		 * The CTS input is inverted for some reason.  -- paulus
356 		 */
357 		if ((status ^ uap->prev_status) & DCD)
358 			uart_handle_dcd_change(&uap->port,
359 					       (status & DCD));
360 		if ((status ^ uap->prev_status) & CTS)
361 			uart_handle_cts_change(&uap->port,
362 					       !(status & CTS));
363 
364 		wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
365 	}
366 
367 	if (status & BRK_ABRT)
368 		uap->flags |= PMACZILOG_FLAG_BREAK;
369 
370 	uap->prev_status = status;
371 }
372 
373 static void pmz_transmit_chars(struct uart_pmac_port *uap)
374 {
375 	struct circ_buf *xmit;
376 
377 	if (ZS_IS_CONS(uap)) {
378 		unsigned char status = read_zsreg(uap, R0);
379 
380 		/* TX still busy?  Just wait for the next TX done interrupt.
381 		 *
382 		 * It can occur because of how we do serial console writes.  It would
383 		 * be nice to transmit console writes just like we normally would for
384 		 * a TTY line. (ie. buffered and TX interrupt driven).  That is not
385 		 * easy because console writes cannot sleep.  One solution might be
386 		 * to poll on enough port->xmit space becoming free.  -DaveM
387 		 */
388 		if (!(status & Tx_BUF_EMP))
389 			return;
390 	}
391 
392 	uap->flags &= ~PMACZILOG_FLAG_TX_ACTIVE;
393 
394 	if (ZS_REGS_HELD(uap)) {
395 		pmz_load_zsregs(uap, uap->curregs);
396 		uap->flags &= ~PMACZILOG_FLAG_REGS_HELD;
397 	}
398 
399 	if (ZS_TX_STOPPED(uap)) {
400 		uap->flags &= ~PMACZILOG_FLAG_TX_STOPPED;
401 		goto ack_tx_int;
402 	}
403 
404 	/* Under some circumstances, we see interrupts reported for
405 	 * a closed channel. The interrupt mask in R1 is clear, but
406 	 * R3 still signals the interrupts and we see them when taking
407 	 * an interrupt for the other channel (this could be a qemu
408 	 * bug but since the ESCC doc doesn't specify precsiely whether
409 	 * R3 interrup status bits are masked by R1 interrupt enable
410 	 * bits, better safe than sorry). --BenH.
411 	 */
412 	if (!ZS_IS_OPEN(uap))
413 		goto ack_tx_int;
414 
415 	if (uap->port.x_char) {
416 		uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
417 		write_zsdata(uap, uap->port.x_char);
418 		zssync(uap);
419 		uap->port.icount.tx++;
420 		uap->port.x_char = 0;
421 		return;
422 	}
423 
424 	if (uap->port.state == NULL)
425 		goto ack_tx_int;
426 	xmit = &uap->port.state->xmit;
427 	if (uart_circ_empty(xmit)) {
428 		uart_write_wakeup(&uap->port);
429 		goto ack_tx_int;
430 	}
431 	if (uart_tx_stopped(&uap->port))
432 		goto ack_tx_int;
433 
434 	uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
435 	write_zsdata(uap, xmit->buf[xmit->tail]);
436 	zssync(uap);
437 
438 	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
439 	uap->port.icount.tx++;
440 
441 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
442 		uart_write_wakeup(&uap->port);
443 
444 	return;
445 
446 ack_tx_int:
447 	write_zsreg(uap, R0, RES_Tx_P);
448 	zssync(uap);
449 }
450 
451 /* Hrm... we register that twice, fixme later.... */
452 static irqreturn_t pmz_interrupt(int irq, void *dev_id)
453 {
454 	struct uart_pmac_port *uap = dev_id;
455 	struct uart_pmac_port *uap_a;
456 	struct uart_pmac_port *uap_b;
457 	int rc = IRQ_NONE;
458 	bool push;
459 	u8 r3;
460 
461 	uap_a = pmz_get_port_A(uap);
462 	uap_b = uap_a->mate;
463 
464 	spin_lock(&uap_a->port.lock);
465 	r3 = read_zsreg(uap_a, R3);
466 
467 #ifdef DEBUG_HARD
468 	pmz_debug("irq, r3: %x\n", r3);
469 #endif
470 	/* Channel A */
471 	push = false;
472 	if (r3 & (CHAEXT | CHATxIP | CHARxIP)) {
473 		if (!ZS_IS_OPEN(uap_a)) {
474 			pmz_debug("ChanA interrupt while not open !\n");
475 			goto skip_a;
476 		}
477 		write_zsreg(uap_a, R0, RES_H_IUS);
478 		zssync(uap_a);
479 		if (r3 & CHAEXT)
480 			pmz_status_handle(uap_a);
481 		if (r3 & CHARxIP)
482 			push = pmz_receive_chars(uap_a);
483 		if (r3 & CHATxIP)
484 			pmz_transmit_chars(uap_a);
485 		rc = IRQ_HANDLED;
486 	}
487  skip_a:
488 	spin_unlock(&uap_a->port.lock);
489 	if (push)
490 		tty_flip_buffer_push(&uap->port.state->port);
491 
492 	if (!uap_b)
493 		goto out;
494 
495 	spin_lock(&uap_b->port.lock);
496 	push = false;
497 	if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) {
498 		if (!ZS_IS_OPEN(uap_b)) {
499 			pmz_debug("ChanB interrupt while not open !\n");
500 			goto skip_b;
501 		}
502 		write_zsreg(uap_b, R0, RES_H_IUS);
503 		zssync(uap_b);
504 		if (r3 & CHBEXT)
505 			pmz_status_handle(uap_b);
506 		if (r3 & CHBRxIP)
507 			push = pmz_receive_chars(uap_b);
508 		if (r3 & CHBTxIP)
509 			pmz_transmit_chars(uap_b);
510 		rc = IRQ_HANDLED;
511 	}
512  skip_b:
513 	spin_unlock(&uap_b->port.lock);
514 	if (push)
515 		tty_flip_buffer_push(&uap->port.state->port);
516 
517  out:
518 	return rc;
519 }
520 
521 /*
522  * Peek the status register, lock not held by caller
523  */
524 static inline u8 pmz_peek_status(struct uart_pmac_port *uap)
525 {
526 	unsigned long flags;
527 	u8 status;
528 
529 	spin_lock_irqsave(&uap->port.lock, flags);
530 	status = read_zsreg(uap, R0);
531 	spin_unlock_irqrestore(&uap->port.lock, flags);
532 
533 	return status;
534 }
535 
536 /*
537  * Check if transmitter is empty
538  * The port lock is not held.
539  */
540 static unsigned int pmz_tx_empty(struct uart_port *port)
541 {
542 	unsigned char status;
543 
544 	status = pmz_peek_status(to_pmz(port));
545 	if (status & Tx_BUF_EMP)
546 		return TIOCSER_TEMT;
547 	return 0;
548 }
549 
550 /*
551  * Set Modem Control (RTS & DTR) bits
552  * The port lock is held and interrupts are disabled.
553  * Note: Shall we really filter out RTS on external ports or
554  * should that be dealt at higher level only ?
555  */
556 static void pmz_set_mctrl(struct uart_port *port, unsigned int mctrl)
557 {
558 	struct uart_pmac_port *uap = to_pmz(port);
559 	unsigned char set_bits, clear_bits;
560 
561         /* Do nothing for irda for now... */
562 	if (ZS_IS_IRDA(uap))
563 		return;
564 	/* We get called during boot with a port not up yet */
565 	if (!(ZS_IS_OPEN(uap) || ZS_IS_CONS(uap)))
566 		return;
567 
568 	set_bits = clear_bits = 0;
569 
570 	if (ZS_IS_INTMODEM(uap)) {
571 		if (mctrl & TIOCM_RTS)
572 			set_bits |= RTS;
573 		else
574 			clear_bits |= RTS;
575 	}
576 	if (mctrl & TIOCM_DTR)
577 		set_bits |= DTR;
578 	else
579 		clear_bits |= DTR;
580 
581 	/* NOTE: Not subject to 'transmitter active' rule.  */
582 	uap->curregs[R5] |= set_bits;
583 	uap->curregs[R5] &= ~clear_bits;
584 
585 	write_zsreg(uap, R5, uap->curregs[R5]);
586 	pmz_debug("pmz_set_mctrl: set bits: %x, clear bits: %x -> %x\n",
587 		  set_bits, clear_bits, uap->curregs[R5]);
588 	zssync(uap);
589 }
590 
591 /*
592  * Get Modem Control bits (only the input ones, the core will
593  * or that with a cached value of the control ones)
594  * The port lock is held and interrupts are disabled.
595  */
596 static unsigned int pmz_get_mctrl(struct uart_port *port)
597 {
598 	struct uart_pmac_port *uap = to_pmz(port);
599 	unsigned char status;
600 	unsigned int ret;
601 
602 	status = read_zsreg(uap, R0);
603 
604 	ret = 0;
605 	if (status & DCD)
606 		ret |= TIOCM_CAR;
607 	if (status & SYNC_HUNT)
608 		ret |= TIOCM_DSR;
609 	if (!(status & CTS))
610 		ret |= TIOCM_CTS;
611 
612 	return ret;
613 }
614 
615 /*
616  * Stop TX side. Dealt like sunzilog at next Tx interrupt,
617  * though for DMA, we will have to do a bit more.
618  * The port lock is held and interrupts are disabled.
619  */
620 static void pmz_stop_tx(struct uart_port *port)
621 {
622 	to_pmz(port)->flags |= PMACZILOG_FLAG_TX_STOPPED;
623 }
624 
625 /*
626  * Kick the Tx side.
627  * The port lock is held and interrupts are disabled.
628  */
629 static void pmz_start_tx(struct uart_port *port)
630 {
631 	struct uart_pmac_port *uap = to_pmz(port);
632 	unsigned char status;
633 
634 	pmz_debug("pmz: start_tx()\n");
635 
636 	uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
637 	uap->flags &= ~PMACZILOG_FLAG_TX_STOPPED;
638 
639 	status = read_zsreg(uap, R0);
640 
641 	/* TX busy?  Just wait for the TX done interrupt.  */
642 	if (!(status & Tx_BUF_EMP))
643 		return;
644 
645 	/* Send the first character to jump-start the TX done
646 	 * IRQ sending engine.
647 	 */
648 	if (port->x_char) {
649 		write_zsdata(uap, port->x_char);
650 		zssync(uap);
651 		port->icount.tx++;
652 		port->x_char = 0;
653 	} else {
654 		struct circ_buf *xmit = &port->state->xmit;
655 
656 		if (uart_circ_empty(xmit))
657 			goto out;
658 		write_zsdata(uap, xmit->buf[xmit->tail]);
659 		zssync(uap);
660 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
661 		port->icount.tx++;
662 
663 		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
664 			uart_write_wakeup(&uap->port);
665 	}
666  out:
667 	pmz_debug("pmz: start_tx() done.\n");
668 }
669 
670 /*
671  * Stop Rx side, basically disable emitting of
672  * Rx interrupts on the port. We don't disable the rx
673  * side of the chip proper though
674  * The port lock is held.
675  */
676 static void pmz_stop_rx(struct uart_port *port)
677 {
678 	struct uart_pmac_port *uap = to_pmz(port);
679 
680 	pmz_debug("pmz: stop_rx()()\n");
681 
682 	/* Disable all RX interrupts.  */
683 	uap->curregs[R1] &= ~RxINT_MASK;
684 	pmz_maybe_update_regs(uap);
685 
686 	pmz_debug("pmz: stop_rx() done.\n");
687 }
688 
689 /*
690  * Enable modem status change interrupts
691  * The port lock is held.
692  */
693 static void pmz_enable_ms(struct uart_port *port)
694 {
695 	struct uart_pmac_port *uap = to_pmz(port);
696 	unsigned char new_reg;
697 
698 	if (ZS_IS_IRDA(uap))
699 		return;
700 	new_reg = uap->curregs[R15] | (DCDIE | SYNCIE | CTSIE);
701 	if (new_reg != uap->curregs[R15]) {
702 		uap->curregs[R15] = new_reg;
703 
704 		/* NOTE: Not subject to 'transmitter active' rule. */
705 		write_zsreg(uap, R15, uap->curregs[R15]);
706 	}
707 }
708 
709 /*
710  * Control break state emission
711  * The port lock is not held.
712  */
713 static void pmz_break_ctl(struct uart_port *port, int break_state)
714 {
715 	struct uart_pmac_port *uap = to_pmz(port);
716 	unsigned char set_bits, clear_bits, new_reg;
717 	unsigned long flags;
718 
719 	set_bits = clear_bits = 0;
720 
721 	if (break_state)
722 		set_bits |= SND_BRK;
723 	else
724 		clear_bits |= SND_BRK;
725 
726 	spin_lock_irqsave(&port->lock, flags);
727 
728 	new_reg = (uap->curregs[R5] | set_bits) & ~clear_bits;
729 	if (new_reg != uap->curregs[R5]) {
730 		uap->curregs[R5] = new_reg;
731 		write_zsreg(uap, R5, uap->curregs[R5]);
732 	}
733 
734 	spin_unlock_irqrestore(&port->lock, flags);
735 }
736 
737 #ifdef CONFIG_PPC_PMAC
738 
739 /*
740  * Turn power on or off to the SCC and associated stuff
741  * (port drivers, modem, IR port, etc.)
742  * Returns the number of milliseconds we should wait before
743  * trying to use the port.
744  */
745 static int pmz_set_scc_power(struct uart_pmac_port *uap, int state)
746 {
747 	int delay = 0;
748 	int rc;
749 
750 	if (state) {
751 		rc = pmac_call_feature(
752 			PMAC_FTR_SCC_ENABLE, uap->node, uap->port_type, 1);
753 		pmz_debug("port power on result: %d\n", rc);
754 		if (ZS_IS_INTMODEM(uap)) {
755 			rc = pmac_call_feature(
756 				PMAC_FTR_MODEM_ENABLE, uap->node, 0, 1);
757 			delay = 2500;	/* wait for 2.5s before using */
758 			pmz_debug("modem power result: %d\n", rc);
759 		}
760 	} else {
761 		/* TODO: Make that depend on a timer, don't power down
762 		 * immediately
763 		 */
764 		if (ZS_IS_INTMODEM(uap)) {
765 			rc = pmac_call_feature(
766 				PMAC_FTR_MODEM_ENABLE, uap->node, 0, 0);
767 			pmz_debug("port power off result: %d\n", rc);
768 		}
769 		pmac_call_feature(PMAC_FTR_SCC_ENABLE, uap->node, uap->port_type, 0);
770 	}
771 	return delay;
772 }
773 
774 #else
775 
776 static int pmz_set_scc_power(struct uart_pmac_port *uap, int state)
777 {
778 	return 0;
779 }
780 
781 #endif /* !CONFIG_PPC_PMAC */
782 
783 /*
784  * FixZeroBug....Works around a bug in the SCC receiving channel.
785  * Inspired from Darwin code, 15 Sept. 2000  -DanM
786  *
787  * The following sequence prevents a problem that is seen with O'Hare ASICs
788  * (most versions -- also with some Heathrow and Hydra ASICs) where a zero
789  * at the input to the receiver becomes 'stuck' and locks up the receiver.
790  * This problem can occur as a result of a zero bit at the receiver input
791  * coincident with any of the following events:
792  *
793  *	The SCC is initialized (hardware or software).
794  *	A framing error is detected.
795  *	The clocking option changes from synchronous or X1 asynchronous
796  *		clocking to X16, X32, or X64 asynchronous clocking.
797  *	The decoding mode is changed among NRZ, NRZI, FM0, or FM1.
798  *
799  * This workaround attempts to recover from the lockup condition by placing
800  * the SCC in synchronous loopback mode with a fast clock before programming
801  * any of the asynchronous modes.
802  */
803 static void pmz_fix_zero_bug_scc(struct uart_pmac_port *uap)
804 {
805 	write_zsreg(uap, 9, ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB);
806 	zssync(uap);
807 	udelay(10);
808 	write_zsreg(uap, 9, (ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB) | NV);
809 	zssync(uap);
810 
811 	write_zsreg(uap, 4, X1CLK | MONSYNC);
812 	write_zsreg(uap, 3, Rx8);
813 	write_zsreg(uap, 5, Tx8 | RTS);
814 	write_zsreg(uap, 9, NV);	/* Didn't we already do this? */
815 	write_zsreg(uap, 11, RCBR | TCBR);
816 	write_zsreg(uap, 12, 0);
817 	write_zsreg(uap, 13, 0);
818 	write_zsreg(uap, 14, (LOOPBAK | BRSRC));
819 	write_zsreg(uap, 14, (LOOPBAK | BRSRC | BRENAB));
820 	write_zsreg(uap, 3, Rx8 | RxENABLE);
821 	write_zsreg(uap, 0, RES_EXT_INT);
822 	write_zsreg(uap, 0, RES_EXT_INT);
823 	write_zsreg(uap, 0, RES_EXT_INT);	/* to kill some time */
824 
825 	/* The channel should be OK now, but it is probably receiving
826 	 * loopback garbage.
827 	 * Switch to asynchronous mode, disable the receiver,
828 	 * and discard everything in the receive buffer.
829 	 */
830 	write_zsreg(uap, 9, NV);
831 	write_zsreg(uap, 4, X16CLK | SB_MASK);
832 	write_zsreg(uap, 3, Rx8);
833 
834 	while (read_zsreg(uap, 0) & Rx_CH_AV) {
835 		(void)read_zsreg(uap, 8);
836 		write_zsreg(uap, 0, RES_EXT_INT);
837 		write_zsreg(uap, 0, ERR_RES);
838 	}
839 }
840 
841 /*
842  * Real startup routine, powers up the hardware and sets up
843  * the SCC. Returns a delay in ms where you need to wait before
844  * actually using the port, this is typically the internal modem
845  * powerup delay. This routine expect the lock to be taken.
846  */
847 static int __pmz_startup(struct uart_pmac_port *uap)
848 {
849 	int pwr_delay = 0;
850 
851 	memset(&uap->curregs, 0, sizeof(uap->curregs));
852 
853 	/* Power up the SCC & underlying hardware (modem/irda) */
854 	pwr_delay = pmz_set_scc_power(uap, 1);
855 
856 	/* Nice buggy HW ... */
857 	pmz_fix_zero_bug_scc(uap);
858 
859 	/* Reset the channel */
860 	uap->curregs[R9] = 0;
861 	write_zsreg(uap, 9, ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB);
862 	zssync(uap);
863 	udelay(10);
864 	write_zsreg(uap, 9, 0);
865 	zssync(uap);
866 
867 	/* Clear the interrupt registers */
868 	write_zsreg(uap, R1, 0);
869 	write_zsreg(uap, R0, ERR_RES);
870 	write_zsreg(uap, R0, ERR_RES);
871 	write_zsreg(uap, R0, RES_H_IUS);
872 	write_zsreg(uap, R0, RES_H_IUS);
873 
874 	/* Setup some valid baud rate */
875 	uap->curregs[R4] = X16CLK | SB1;
876 	uap->curregs[R3] = Rx8;
877 	uap->curregs[R5] = Tx8 | RTS;
878 	if (!ZS_IS_IRDA(uap))
879 		uap->curregs[R5] |= DTR;
880 	uap->curregs[R12] = 0;
881 	uap->curregs[R13] = 0;
882 	uap->curregs[R14] = BRENAB;
883 
884 	/* Clear handshaking, enable BREAK interrupts */
885 	uap->curregs[R15] = BRKIE;
886 
887 	/* Master interrupt enable */
888 	uap->curregs[R9] |= NV | MIE;
889 
890 	pmz_load_zsregs(uap, uap->curregs);
891 
892 	/* Enable receiver and transmitter.  */
893 	write_zsreg(uap, R3, uap->curregs[R3] |= RxENABLE);
894 	write_zsreg(uap, R5, uap->curregs[R5] |= TxENABLE);
895 
896 	/* Remember status for DCD/CTS changes */
897 	uap->prev_status = read_zsreg(uap, R0);
898 
899 	return pwr_delay;
900 }
901 
902 static void pmz_irda_reset(struct uart_pmac_port *uap)
903 {
904 	unsigned long flags;
905 
906 	spin_lock_irqsave(&uap->port.lock, flags);
907 	uap->curregs[R5] |= DTR;
908 	write_zsreg(uap, R5, uap->curregs[R5]);
909 	zssync(uap);
910 	spin_unlock_irqrestore(&uap->port.lock, flags);
911 	msleep(110);
912 
913 	spin_lock_irqsave(&uap->port.lock, flags);
914 	uap->curregs[R5] &= ~DTR;
915 	write_zsreg(uap, R5, uap->curregs[R5]);
916 	zssync(uap);
917 	spin_unlock_irqrestore(&uap->port.lock, flags);
918 	msleep(10);
919 }
920 
921 /*
922  * This is the "normal" startup routine, using the above one
923  * wrapped with the lock and doing a schedule delay
924  */
925 static int pmz_startup(struct uart_port *port)
926 {
927 	struct uart_pmac_port *uap = to_pmz(port);
928 	unsigned long flags;
929 	int pwr_delay = 0;
930 
931 	pmz_debug("pmz: startup()\n");
932 
933 	uap->flags |= PMACZILOG_FLAG_IS_OPEN;
934 
935 	/* A console is never powered down. Else, power up and
936 	 * initialize the chip
937 	 */
938 	if (!ZS_IS_CONS(uap)) {
939 		spin_lock_irqsave(&port->lock, flags);
940 		pwr_delay = __pmz_startup(uap);
941 		spin_unlock_irqrestore(&port->lock, flags);
942 	}
943 	sprintf(uap->irq_name, PMACZILOG_NAME"%d", uap->port.line);
944 	if (request_irq(uap->port.irq, pmz_interrupt, IRQF_SHARED,
945 			uap->irq_name, uap)) {
946 		pmz_error("Unable to register zs interrupt handler.\n");
947 		pmz_set_scc_power(uap, 0);
948 		return -ENXIO;
949 	}
950 
951 	/* Right now, we deal with delay by blocking here, I'll be
952 	 * smarter later on
953 	 */
954 	if (pwr_delay != 0) {
955 		pmz_debug("pmz: delaying %d ms\n", pwr_delay);
956 		msleep(pwr_delay);
957 	}
958 
959 	/* IrDA reset is done now */
960 	if (ZS_IS_IRDA(uap))
961 		pmz_irda_reset(uap);
962 
963 	/* Enable interrupt requests for the channel */
964 	spin_lock_irqsave(&port->lock, flags);
965 	pmz_interrupt_control(uap, 1);
966 	spin_unlock_irqrestore(&port->lock, flags);
967 
968 	pmz_debug("pmz: startup() done.\n");
969 
970 	return 0;
971 }
972 
973 static void pmz_shutdown(struct uart_port *port)
974 {
975 	struct uart_pmac_port *uap = to_pmz(port);
976 	unsigned long flags;
977 
978 	pmz_debug("pmz: shutdown()\n");
979 
980 	spin_lock_irqsave(&port->lock, flags);
981 
982 	/* Disable interrupt requests for the channel */
983 	pmz_interrupt_control(uap, 0);
984 
985 	if (!ZS_IS_CONS(uap)) {
986 		/* Disable receiver and transmitter */
987 		uap->curregs[R3] &= ~RxENABLE;
988 		uap->curregs[R5] &= ~TxENABLE;
989 
990 		/* Disable break assertion */
991 		uap->curregs[R5] &= ~SND_BRK;
992 		pmz_maybe_update_regs(uap);
993 	}
994 
995 	spin_unlock_irqrestore(&port->lock, flags);
996 
997 	/* Release interrupt handler */
998 	free_irq(uap->port.irq, uap);
999 
1000 	spin_lock_irqsave(&port->lock, flags);
1001 
1002 	uap->flags &= ~PMACZILOG_FLAG_IS_OPEN;
1003 
1004 	if (!ZS_IS_CONS(uap))
1005 		pmz_set_scc_power(uap, 0);	/* Shut the chip down */
1006 
1007 	spin_unlock_irqrestore(&port->lock, flags);
1008 
1009 	pmz_debug("pmz: shutdown() done.\n");
1010 }
1011 
1012 /* Shared by TTY driver and serial console setup.  The port lock is held
1013  * and local interrupts are disabled.
1014  */
1015 static void pmz_convert_to_zs(struct uart_pmac_port *uap, unsigned int cflag,
1016 			      unsigned int iflag, unsigned long baud)
1017 {
1018 	int brg;
1019 
1020 	/* Switch to external clocking for IrDA high clock rates. That
1021 	 * code could be re-used for Midi interfaces with different
1022 	 * multipliers
1023 	 */
1024 	if (baud >= 115200 && ZS_IS_IRDA(uap)) {
1025 		uap->curregs[R4] = X1CLK;
1026 		uap->curregs[R11] = RCTRxCP | TCTRxCP;
1027 		uap->curregs[R14] = 0; /* BRG off */
1028 		uap->curregs[R12] = 0;
1029 		uap->curregs[R13] = 0;
1030 		uap->flags |= PMACZILOG_FLAG_IS_EXTCLK;
1031 	} else {
1032 		switch (baud) {
1033 		case ZS_CLOCK/16:	/* 230400 */
1034 			uap->curregs[R4] = X16CLK;
1035 			uap->curregs[R11] = 0;
1036 			uap->curregs[R14] = 0;
1037 			break;
1038 		case ZS_CLOCK/32:	/* 115200 */
1039 			uap->curregs[R4] = X32CLK;
1040 			uap->curregs[R11] = 0;
1041 			uap->curregs[R14] = 0;
1042 			break;
1043 		default:
1044 			uap->curregs[R4] = X16CLK;
1045 			uap->curregs[R11] = TCBR | RCBR;
1046 			brg = BPS_TO_BRG(baud, ZS_CLOCK / 16);
1047 			uap->curregs[R12] = (brg & 255);
1048 			uap->curregs[R13] = ((brg >> 8) & 255);
1049 			uap->curregs[R14] = BRENAB;
1050 		}
1051 		uap->flags &= ~PMACZILOG_FLAG_IS_EXTCLK;
1052 	}
1053 
1054 	/* Character size, stop bits, and parity. */
1055 	uap->curregs[3] &= ~RxN_MASK;
1056 	uap->curregs[5] &= ~TxN_MASK;
1057 
1058 	switch (cflag & CSIZE) {
1059 	case CS5:
1060 		uap->curregs[3] |= Rx5;
1061 		uap->curregs[5] |= Tx5;
1062 		uap->parity_mask = 0x1f;
1063 		break;
1064 	case CS6:
1065 		uap->curregs[3] |= Rx6;
1066 		uap->curregs[5] |= Tx6;
1067 		uap->parity_mask = 0x3f;
1068 		break;
1069 	case CS7:
1070 		uap->curregs[3] |= Rx7;
1071 		uap->curregs[5] |= Tx7;
1072 		uap->parity_mask = 0x7f;
1073 		break;
1074 	case CS8:
1075 	default:
1076 		uap->curregs[3] |= Rx8;
1077 		uap->curregs[5] |= Tx8;
1078 		uap->parity_mask = 0xff;
1079 		break;
1080 	}
1081 	uap->curregs[4] &= ~(SB_MASK);
1082 	if (cflag & CSTOPB)
1083 		uap->curregs[4] |= SB2;
1084 	else
1085 		uap->curregs[4] |= SB1;
1086 	if (cflag & PARENB)
1087 		uap->curregs[4] |= PAR_ENAB;
1088 	else
1089 		uap->curregs[4] &= ~PAR_ENAB;
1090 	if (!(cflag & PARODD))
1091 		uap->curregs[4] |= PAR_EVEN;
1092 	else
1093 		uap->curregs[4] &= ~PAR_EVEN;
1094 
1095 	uap->port.read_status_mask = Rx_OVR;
1096 	if (iflag & INPCK)
1097 		uap->port.read_status_mask |= CRC_ERR | PAR_ERR;
1098 	if (iflag & (IGNBRK | BRKINT | PARMRK))
1099 		uap->port.read_status_mask |= BRK_ABRT;
1100 
1101 	uap->port.ignore_status_mask = 0;
1102 	if (iflag & IGNPAR)
1103 		uap->port.ignore_status_mask |= CRC_ERR | PAR_ERR;
1104 	if (iflag & IGNBRK) {
1105 		uap->port.ignore_status_mask |= BRK_ABRT;
1106 		if (iflag & IGNPAR)
1107 			uap->port.ignore_status_mask |= Rx_OVR;
1108 	}
1109 
1110 	if ((cflag & CREAD) == 0)
1111 		uap->port.ignore_status_mask = 0xff;
1112 }
1113 
1114 
1115 /*
1116  * Set the irda codec on the imac to the specified baud rate.
1117  */
1118 static void pmz_irda_setup(struct uart_pmac_port *uap, unsigned long *baud)
1119 {
1120 	u8 cmdbyte;
1121 	int t, version;
1122 
1123 	switch (*baud) {
1124 	/* SIR modes */
1125 	case 2400:
1126 		cmdbyte = 0x53;
1127 		break;
1128 	case 4800:
1129 		cmdbyte = 0x52;
1130 		break;
1131 	case 9600:
1132 		cmdbyte = 0x51;
1133 		break;
1134 	case 19200:
1135 		cmdbyte = 0x50;
1136 		break;
1137 	case 38400:
1138 		cmdbyte = 0x4f;
1139 		break;
1140 	case 57600:
1141 		cmdbyte = 0x4e;
1142 		break;
1143 	case 115200:
1144 		cmdbyte = 0x4d;
1145 		break;
1146 	/* The FIR modes aren't really supported at this point, how
1147 	 * do we select the speed ? via the FCR on KeyLargo ?
1148 	 */
1149 	case 1152000:
1150 		cmdbyte = 0;
1151 		break;
1152 	case 4000000:
1153 		cmdbyte = 0;
1154 		break;
1155 	default: /* 9600 */
1156 		cmdbyte = 0x51;
1157 		*baud = 9600;
1158 		break;
1159 	}
1160 
1161 	/* Wait for transmitter to drain */
1162 	t = 10000;
1163 	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0
1164 	       || (read_zsreg(uap, R1) & ALL_SNT) == 0) {
1165 		if (--t <= 0) {
1166 			pmz_error("transmitter didn't drain\n");
1167 			return;
1168 		}
1169 		udelay(10);
1170 	}
1171 
1172 	/* Drain the receiver too */
1173 	t = 100;
1174 	(void)read_zsdata(uap);
1175 	(void)read_zsdata(uap);
1176 	(void)read_zsdata(uap);
1177 	mdelay(10);
1178 	while (read_zsreg(uap, R0) & Rx_CH_AV) {
1179 		read_zsdata(uap);
1180 		mdelay(10);
1181 		if (--t <= 0) {
1182 			pmz_error("receiver didn't drain\n");
1183 			return;
1184 		}
1185 	}
1186 
1187 	/* Switch to command mode */
1188 	uap->curregs[R5] |= DTR;
1189 	write_zsreg(uap, R5, uap->curregs[R5]);
1190 	zssync(uap);
1191 	mdelay(1);
1192 
1193 	/* Switch SCC to 19200 */
1194 	pmz_convert_to_zs(uap, CS8, 0, 19200);
1195 	pmz_load_zsregs(uap, uap->curregs);
1196 	mdelay(1);
1197 
1198 	/* Write get_version command byte */
1199 	write_zsdata(uap, 1);
1200 	t = 5000;
1201 	while ((read_zsreg(uap, R0) & Rx_CH_AV) == 0) {
1202 		if (--t <= 0) {
1203 			pmz_error("irda_setup timed out on get_version byte\n");
1204 			goto out;
1205 		}
1206 		udelay(10);
1207 	}
1208 	version = read_zsdata(uap);
1209 
1210 	if (version < 4) {
1211 		pmz_info("IrDA: dongle version %d not supported\n", version);
1212 		goto out;
1213 	}
1214 
1215 	/* Send speed mode */
1216 	write_zsdata(uap, cmdbyte);
1217 	t = 5000;
1218 	while ((read_zsreg(uap, R0) & Rx_CH_AV) == 0) {
1219 		if (--t <= 0) {
1220 			pmz_error("irda_setup timed out on speed mode byte\n");
1221 			goto out;
1222 		}
1223 		udelay(10);
1224 	}
1225 	t = read_zsdata(uap);
1226 	if (t != cmdbyte)
1227 		pmz_error("irda_setup speed mode byte = %x (%x)\n", t, cmdbyte);
1228 
1229 	pmz_info("IrDA setup for %ld bps, dongle version: %d\n",
1230 		 *baud, version);
1231 
1232 	(void)read_zsdata(uap);
1233 	(void)read_zsdata(uap);
1234 	(void)read_zsdata(uap);
1235 
1236  out:
1237 	/* Switch back to data mode */
1238 	uap->curregs[R5] &= ~DTR;
1239 	write_zsreg(uap, R5, uap->curregs[R5]);
1240 	zssync(uap);
1241 
1242 	(void)read_zsdata(uap);
1243 	(void)read_zsdata(uap);
1244 	(void)read_zsdata(uap);
1245 }
1246 
1247 
1248 static void __pmz_set_termios(struct uart_port *port, struct ktermios *termios,
1249 			      struct ktermios *old)
1250 {
1251 	struct uart_pmac_port *uap = to_pmz(port);
1252 	unsigned long baud;
1253 
1254 	pmz_debug("pmz: set_termios()\n");
1255 
1256 	memcpy(&uap->termios_cache, termios, sizeof(struct ktermios));
1257 
1258 	/* XXX Check which revs of machines actually allow 1 and 4Mb speeds
1259 	 * on the IR dongle. Note that the IRTTY driver currently doesn't know
1260 	 * about the FIR mode and high speed modes. So these are unused. For
1261 	 * implementing proper support for these, we should probably add some
1262 	 * DMA as well, at least on the Rx side, which isn't a simple thing
1263 	 * at this point.
1264 	 */
1265 	if (ZS_IS_IRDA(uap)) {
1266 		/* Calc baud rate */
1267 		baud = uart_get_baud_rate(port, termios, old, 1200, 4000000);
1268 		pmz_debug("pmz: switch IRDA to %ld bauds\n", baud);
1269 		/* Cet the irda codec to the right rate */
1270 		pmz_irda_setup(uap, &baud);
1271 		/* Set final baud rate */
1272 		pmz_convert_to_zs(uap, termios->c_cflag, termios->c_iflag, baud);
1273 		pmz_load_zsregs(uap, uap->curregs);
1274 		zssync(uap);
1275 	} else {
1276 		baud = uart_get_baud_rate(port, termios, old, 1200, 230400);
1277 		pmz_convert_to_zs(uap, termios->c_cflag, termios->c_iflag, baud);
1278 		/* Make sure modem status interrupts are correctly configured */
1279 		if (UART_ENABLE_MS(&uap->port, termios->c_cflag)) {
1280 			uap->curregs[R15] |= DCDIE | SYNCIE | CTSIE;
1281 			uap->flags |= PMACZILOG_FLAG_MODEM_STATUS;
1282 		} else {
1283 			uap->curregs[R15] &= ~(DCDIE | SYNCIE | CTSIE);
1284 			uap->flags &= ~PMACZILOG_FLAG_MODEM_STATUS;
1285 		}
1286 
1287 		/* Load registers to the chip */
1288 		pmz_maybe_update_regs(uap);
1289 	}
1290 	uart_update_timeout(port, termios->c_cflag, baud);
1291 
1292 	pmz_debug("pmz: set_termios() done.\n");
1293 }
1294 
1295 /* The port lock is not held.  */
1296 static void pmz_set_termios(struct uart_port *port, struct ktermios *termios,
1297 			    struct ktermios *old)
1298 {
1299 	struct uart_pmac_port *uap = to_pmz(port);
1300 	unsigned long flags;
1301 
1302 	spin_lock_irqsave(&port->lock, flags);
1303 
1304 	/* Disable IRQs on the port */
1305 	pmz_interrupt_control(uap, 0);
1306 
1307 	/* Setup new port configuration */
1308 	__pmz_set_termios(port, termios, old);
1309 
1310 	/* Re-enable IRQs on the port */
1311 	if (ZS_IS_OPEN(uap))
1312 		pmz_interrupt_control(uap, 1);
1313 
1314 	spin_unlock_irqrestore(&port->lock, flags);
1315 }
1316 
1317 static const char *pmz_type(struct uart_port *port)
1318 {
1319 	struct uart_pmac_port *uap = to_pmz(port);
1320 
1321 	if (ZS_IS_IRDA(uap))
1322 		return "Z85c30 ESCC - Infrared port";
1323 	else if (ZS_IS_INTMODEM(uap))
1324 		return "Z85c30 ESCC - Internal modem";
1325 	return "Z85c30 ESCC - Serial port";
1326 }
1327 
1328 /* We do not request/release mappings of the registers here, this
1329  * happens at early serial probe time.
1330  */
1331 static void pmz_release_port(struct uart_port *port)
1332 {
1333 }
1334 
1335 static int pmz_request_port(struct uart_port *port)
1336 {
1337 	return 0;
1338 }
1339 
1340 /* These do not need to do anything interesting either.  */
1341 static void pmz_config_port(struct uart_port *port, int flags)
1342 {
1343 }
1344 
1345 /* We do not support letting the user mess with the divisor, IRQ, etc. */
1346 static int pmz_verify_port(struct uart_port *port, struct serial_struct *ser)
1347 {
1348 	return -EINVAL;
1349 }
1350 
1351 #ifdef CONFIG_CONSOLE_POLL
1352 
1353 static int pmz_poll_get_char(struct uart_port *port)
1354 {
1355 	struct uart_pmac_port *uap = (struct uart_pmac_port *)port;
1356 	int tries = 2;
1357 
1358 	while (tries) {
1359 		if ((read_zsreg(uap, R0) & Rx_CH_AV) != 0)
1360 			return read_zsdata(uap);
1361 		if (tries--)
1362 			udelay(5);
1363 	}
1364 
1365 	return NO_POLL_CHAR;
1366 }
1367 
1368 static void pmz_poll_put_char(struct uart_port *port, unsigned char c)
1369 {
1370 	struct uart_pmac_port *uap = (struct uart_pmac_port *)port;
1371 
1372 	/* Wait for the transmit buffer to empty. */
1373 	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0)
1374 		udelay(5);
1375 	write_zsdata(uap, c);
1376 }
1377 
1378 #endif /* CONFIG_CONSOLE_POLL */
1379 
1380 static struct uart_ops pmz_pops = {
1381 	.tx_empty	=	pmz_tx_empty,
1382 	.set_mctrl	=	pmz_set_mctrl,
1383 	.get_mctrl	=	pmz_get_mctrl,
1384 	.stop_tx	=	pmz_stop_tx,
1385 	.start_tx	=	pmz_start_tx,
1386 	.stop_rx	=	pmz_stop_rx,
1387 	.enable_ms	=	pmz_enable_ms,
1388 	.break_ctl	=	pmz_break_ctl,
1389 	.startup	=	pmz_startup,
1390 	.shutdown	=	pmz_shutdown,
1391 	.set_termios	=	pmz_set_termios,
1392 	.type		=	pmz_type,
1393 	.release_port	=	pmz_release_port,
1394 	.request_port	=	pmz_request_port,
1395 	.config_port	=	pmz_config_port,
1396 	.verify_port	=	pmz_verify_port,
1397 #ifdef CONFIG_CONSOLE_POLL
1398 	.poll_get_char	=	pmz_poll_get_char,
1399 	.poll_put_char	=	pmz_poll_put_char,
1400 #endif
1401 };
1402 
1403 #ifdef CONFIG_PPC_PMAC
1404 
1405 /*
1406  * Setup one port structure after probing, HW is down at this point,
1407  * Unlike sunzilog, we don't need to pre-init the spinlock as we don't
1408  * register our console before uart_add_one_port() is called
1409  */
1410 static int __init pmz_init_port(struct uart_pmac_port *uap)
1411 {
1412 	struct device_node *np = uap->node;
1413 	const char *conn;
1414 	const struct slot_names_prop {
1415 		int	count;
1416 		char	name[1];
1417 	} *slots;
1418 	int len;
1419 	struct resource r_ports, r_rxdma, r_txdma;
1420 
1421 	/*
1422 	 * Request & map chip registers
1423 	 */
1424 	if (of_address_to_resource(np, 0, &r_ports))
1425 		return -ENODEV;
1426 	uap->port.mapbase = r_ports.start;
1427 	uap->port.membase = ioremap(uap->port.mapbase, 0x1000);
1428 
1429 	uap->control_reg = uap->port.membase;
1430 	uap->data_reg = uap->control_reg + 0x10;
1431 
1432 	/*
1433 	 * Request & map DBDMA registers
1434 	 */
1435 #ifdef HAS_DBDMA
1436 	if (of_address_to_resource(np, 1, &r_txdma) == 0 &&
1437 	    of_address_to_resource(np, 2, &r_rxdma) == 0)
1438 		uap->flags |= PMACZILOG_FLAG_HAS_DMA;
1439 #else
1440 	memset(&r_txdma, 0, sizeof(struct resource));
1441 	memset(&r_rxdma, 0, sizeof(struct resource));
1442 #endif
1443 	if (ZS_HAS_DMA(uap)) {
1444 		uap->tx_dma_regs = ioremap(r_txdma.start, 0x100);
1445 		if (uap->tx_dma_regs == NULL) {
1446 			uap->flags &= ~PMACZILOG_FLAG_HAS_DMA;
1447 			goto no_dma;
1448 		}
1449 		uap->rx_dma_regs = ioremap(r_rxdma.start, 0x100);
1450 		if (uap->rx_dma_regs == NULL) {
1451 			iounmap(uap->tx_dma_regs);
1452 			uap->tx_dma_regs = NULL;
1453 			uap->flags &= ~PMACZILOG_FLAG_HAS_DMA;
1454 			goto no_dma;
1455 		}
1456 		uap->tx_dma_irq = irq_of_parse_and_map(np, 1);
1457 		uap->rx_dma_irq = irq_of_parse_and_map(np, 2);
1458 	}
1459 no_dma:
1460 
1461 	/*
1462 	 * Detect port type
1463 	 */
1464 	if (of_device_is_compatible(np, "cobalt"))
1465 		uap->flags |= PMACZILOG_FLAG_IS_INTMODEM;
1466 	conn = of_get_property(np, "AAPL,connector", &len);
1467 	if (conn && (strcmp(conn, "infrared") == 0))
1468 		uap->flags |= PMACZILOG_FLAG_IS_IRDA;
1469 	uap->port_type = PMAC_SCC_ASYNC;
1470 	/* 1999 Powerbook G3 has slot-names property instead */
1471 	slots = of_get_property(np, "slot-names", &len);
1472 	if (slots && slots->count > 0) {
1473 		if (strcmp(slots->name, "IrDA") == 0)
1474 			uap->flags |= PMACZILOG_FLAG_IS_IRDA;
1475 		else if (strcmp(slots->name, "Modem") == 0)
1476 			uap->flags |= PMACZILOG_FLAG_IS_INTMODEM;
1477 	}
1478 	if (ZS_IS_IRDA(uap))
1479 		uap->port_type = PMAC_SCC_IRDA;
1480 	if (ZS_IS_INTMODEM(uap)) {
1481 		struct device_node* i2c_modem =
1482 			of_find_node_by_name(NULL, "i2c-modem");
1483 		if (i2c_modem) {
1484 			const char* mid =
1485 				of_get_property(i2c_modem, "modem-id", NULL);
1486 			if (mid) switch(*mid) {
1487 			case 0x04 :
1488 			case 0x05 :
1489 			case 0x07 :
1490 			case 0x08 :
1491 			case 0x0b :
1492 			case 0x0c :
1493 				uap->port_type = PMAC_SCC_I2S1;
1494 			}
1495 			printk(KERN_INFO "pmac_zilog: i2c-modem detected, id: %d\n",
1496 				mid ? (*mid) : 0);
1497 			of_node_put(i2c_modem);
1498 		} else {
1499 			printk(KERN_INFO "pmac_zilog: serial modem detected\n");
1500 		}
1501 	}
1502 
1503 	/*
1504 	 * Init remaining bits of "port" structure
1505 	 */
1506 	uap->port.iotype = UPIO_MEM;
1507 	uap->port.irq = irq_of_parse_and_map(np, 0);
1508 	uap->port.uartclk = ZS_CLOCK;
1509 	uap->port.fifosize = 1;
1510 	uap->port.ops = &pmz_pops;
1511 	uap->port.type = PORT_PMAC_ZILOG;
1512 	uap->port.flags = 0;
1513 
1514 	/*
1515 	 * Fixup for the port on Gatwick for which the device-tree has
1516 	 * missing interrupts. Normally, the macio_dev would contain
1517 	 * fixed up interrupt info, but we use the device-tree directly
1518 	 * here due to early probing so we need the fixup too.
1519 	 */
1520 	if (uap->port.irq == 0 &&
1521 	    np->parent && np->parent->parent &&
1522 	    of_device_is_compatible(np->parent->parent, "gatwick")) {
1523 		/* IRQs on gatwick are offset by 64 */
1524 		uap->port.irq = irq_create_mapping(NULL, 64 + 15);
1525 		uap->tx_dma_irq = irq_create_mapping(NULL, 64 + 4);
1526 		uap->rx_dma_irq = irq_create_mapping(NULL, 64 + 5);
1527 	}
1528 
1529 	/* Setup some valid baud rate information in the register
1530 	 * shadows so we don't write crap there before baud rate is
1531 	 * first initialized.
1532 	 */
1533 	pmz_convert_to_zs(uap, CS8, 0, 9600);
1534 
1535 	return 0;
1536 }
1537 
1538 /*
1539  * Get rid of a port on module removal
1540  */
1541 static void pmz_dispose_port(struct uart_pmac_port *uap)
1542 {
1543 	struct device_node *np;
1544 
1545 	np = uap->node;
1546 	iounmap(uap->rx_dma_regs);
1547 	iounmap(uap->tx_dma_regs);
1548 	iounmap(uap->control_reg);
1549 	uap->node = NULL;
1550 	of_node_put(np);
1551 	memset(uap, 0, sizeof(struct uart_pmac_port));
1552 }
1553 
1554 /*
1555  * Called upon match with an escc node in the device-tree.
1556  */
1557 static int pmz_attach(struct macio_dev *mdev, const struct of_device_id *match)
1558 {
1559 	struct uart_pmac_port *uap;
1560 	int i;
1561 
1562 	/* Iterate the pmz_ports array to find a matching entry
1563 	 */
1564 	for (i = 0; i < MAX_ZS_PORTS; i++)
1565 		if (pmz_ports[i].node == mdev->ofdev.dev.of_node)
1566 			break;
1567 	if (i >= MAX_ZS_PORTS)
1568 		return -ENODEV;
1569 
1570 
1571 	uap = &pmz_ports[i];
1572 	uap->dev = mdev;
1573 	uap->port.dev = &mdev->ofdev.dev;
1574 	dev_set_drvdata(&mdev->ofdev.dev, uap);
1575 
1576 	/* We still activate the port even when failing to request resources
1577 	 * to work around bugs in ancient Apple device-trees
1578 	 */
1579 	if (macio_request_resources(uap->dev, "pmac_zilog"))
1580 		printk(KERN_WARNING "%s: Failed to request resource"
1581 		       ", port still active\n",
1582 		       uap->node->name);
1583 	else
1584 		uap->flags |= PMACZILOG_FLAG_RSRC_REQUESTED;
1585 
1586 	return uart_add_one_port(&pmz_uart_reg, &uap->port);
1587 }
1588 
1589 /*
1590  * That one should not be called, macio isn't really a hotswap device,
1591  * we don't expect one of those serial ports to go away...
1592  */
1593 static int pmz_detach(struct macio_dev *mdev)
1594 {
1595 	struct uart_pmac_port	*uap = dev_get_drvdata(&mdev->ofdev.dev);
1596 
1597 	if (!uap)
1598 		return -ENODEV;
1599 
1600 	uart_remove_one_port(&pmz_uart_reg, &uap->port);
1601 
1602 	if (uap->flags & PMACZILOG_FLAG_RSRC_REQUESTED) {
1603 		macio_release_resources(uap->dev);
1604 		uap->flags &= ~PMACZILOG_FLAG_RSRC_REQUESTED;
1605 	}
1606 	dev_set_drvdata(&mdev->ofdev.dev, NULL);
1607 	uap->dev = NULL;
1608 	uap->port.dev = NULL;
1609 
1610 	return 0;
1611 }
1612 
1613 
1614 static int pmz_suspend(struct macio_dev *mdev, pm_message_t pm_state)
1615 {
1616 	struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev);
1617 
1618 	if (uap == NULL) {
1619 		printk("HRM... pmz_suspend with NULL uap\n");
1620 		return 0;
1621 	}
1622 
1623 	uart_suspend_port(&pmz_uart_reg, &uap->port);
1624 
1625 	return 0;
1626 }
1627 
1628 
1629 static int pmz_resume(struct macio_dev *mdev)
1630 {
1631 	struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev);
1632 
1633 	if (uap == NULL)
1634 		return 0;
1635 
1636 	uart_resume_port(&pmz_uart_reg, &uap->port);
1637 
1638 	return 0;
1639 }
1640 
1641 /*
1642  * Probe all ports in the system and build the ports array, we register
1643  * with the serial layer later, so we get a proper struct device which
1644  * allows the tty to attach properly. This is later than it used to be
1645  * but the tty layer really wants it that way.
1646  */
1647 static int __init pmz_probe(void)
1648 {
1649 	struct device_node	*node_p, *node_a, *node_b, *np;
1650 	int			count = 0;
1651 	int			rc;
1652 
1653 	/*
1654 	 * Find all escc chips in the system
1655 	 */
1656 	for_each_node_by_name(node_p, "escc") {
1657 		/*
1658 		 * First get channel A/B node pointers
1659 		 *
1660 		 * TODO: Add routines with proper locking to do that...
1661 		 */
1662 		node_a = node_b = NULL;
1663 		for (np = NULL; (np = of_get_next_child(node_p, np)) != NULL;) {
1664 			if (strncmp(np->name, "ch-a", 4) == 0)
1665 				node_a = of_node_get(np);
1666 			else if (strncmp(np->name, "ch-b", 4) == 0)
1667 				node_b = of_node_get(np);
1668 		}
1669 		if (!node_a && !node_b) {
1670 			of_node_put(node_a);
1671 			of_node_put(node_b);
1672 			printk(KERN_ERR "pmac_zilog: missing node %c for escc %s\n",
1673 				(!node_a) ? 'a' : 'b', node_p->full_name);
1674 			continue;
1675 		}
1676 
1677 		/*
1678 		 * Fill basic fields in the port structures
1679 		 */
1680 		if (node_b != NULL) {
1681 			pmz_ports[count].mate		= &pmz_ports[count+1];
1682 			pmz_ports[count+1].mate		= &pmz_ports[count];
1683 		}
1684 		pmz_ports[count].flags		= PMACZILOG_FLAG_IS_CHANNEL_A;
1685 		pmz_ports[count].node		= node_a;
1686 		pmz_ports[count+1].node		= node_b;
1687 		pmz_ports[count].port.line	= count;
1688 		pmz_ports[count+1].port.line	= count+1;
1689 
1690 		/*
1691 		 * Setup the ports for real
1692 		 */
1693 		rc = pmz_init_port(&pmz_ports[count]);
1694 		if (rc == 0 && node_b != NULL)
1695 			rc = pmz_init_port(&pmz_ports[count+1]);
1696 		if (rc != 0) {
1697 			of_node_put(node_a);
1698 			of_node_put(node_b);
1699 			memset(&pmz_ports[count], 0, sizeof(struct uart_pmac_port));
1700 			memset(&pmz_ports[count+1], 0, sizeof(struct uart_pmac_port));
1701 			continue;
1702 		}
1703 		count += 2;
1704 	}
1705 	pmz_ports_count = count;
1706 
1707 	return 0;
1708 }
1709 
1710 #else
1711 
1712 extern struct platform_device scc_a_pdev, scc_b_pdev;
1713 
1714 static int __init pmz_init_port(struct uart_pmac_port *uap)
1715 {
1716 	struct resource *r_ports;
1717 	int irq;
1718 
1719 	r_ports = platform_get_resource(uap->pdev, IORESOURCE_MEM, 0);
1720 	irq = platform_get_irq(uap->pdev, 0);
1721 	if (!r_ports || !irq)
1722 		return -ENODEV;
1723 
1724 	uap->port.mapbase  = r_ports->start;
1725 	uap->port.membase  = (unsigned char __iomem *) r_ports->start;
1726 	uap->port.iotype   = UPIO_MEM;
1727 	uap->port.irq      = irq;
1728 	uap->port.uartclk  = ZS_CLOCK;
1729 	uap->port.fifosize = 1;
1730 	uap->port.ops      = &pmz_pops;
1731 	uap->port.type     = PORT_PMAC_ZILOG;
1732 	uap->port.flags    = 0;
1733 
1734 	uap->control_reg   = uap->port.membase;
1735 	uap->data_reg      = uap->control_reg + 4;
1736 	uap->port_type     = 0;
1737 
1738 	pmz_convert_to_zs(uap, CS8, 0, 9600);
1739 
1740 	return 0;
1741 }
1742 
1743 static int __init pmz_probe(void)
1744 {
1745 	int err;
1746 
1747 	pmz_ports_count = 0;
1748 
1749 	pmz_ports[0].port.line = 0;
1750 	pmz_ports[0].flags     = PMACZILOG_FLAG_IS_CHANNEL_A;
1751 	pmz_ports[0].pdev      = &scc_a_pdev;
1752 	err = pmz_init_port(&pmz_ports[0]);
1753 	if (err)
1754 		return err;
1755 	pmz_ports_count++;
1756 
1757 	pmz_ports[0].mate      = &pmz_ports[1];
1758 	pmz_ports[1].mate      = &pmz_ports[0];
1759 	pmz_ports[1].port.line = 1;
1760 	pmz_ports[1].flags     = 0;
1761 	pmz_ports[1].pdev      = &scc_b_pdev;
1762 	err = pmz_init_port(&pmz_ports[1]);
1763 	if (err)
1764 		return err;
1765 	pmz_ports_count++;
1766 
1767 	return 0;
1768 }
1769 
1770 static void pmz_dispose_port(struct uart_pmac_port *uap)
1771 {
1772 	memset(uap, 0, sizeof(struct uart_pmac_port));
1773 }
1774 
1775 static int __init pmz_attach(struct platform_device *pdev)
1776 {
1777 	struct uart_pmac_port *uap;
1778 	int i;
1779 
1780 	/* Iterate the pmz_ports array to find a matching entry */
1781 	for (i = 0; i < pmz_ports_count; i++)
1782 		if (pmz_ports[i].pdev == pdev)
1783 			break;
1784 	if (i >= pmz_ports_count)
1785 		return -ENODEV;
1786 
1787 	uap = &pmz_ports[i];
1788 	uap->port.dev = &pdev->dev;
1789 	platform_set_drvdata(pdev, uap);
1790 
1791 	return uart_add_one_port(&pmz_uart_reg, &uap->port);
1792 }
1793 
1794 static int __exit pmz_detach(struct platform_device *pdev)
1795 {
1796 	struct uart_pmac_port *uap = platform_get_drvdata(pdev);
1797 
1798 	if (!uap)
1799 		return -ENODEV;
1800 
1801 	uart_remove_one_port(&pmz_uart_reg, &uap->port);
1802 
1803 	uap->port.dev = NULL;
1804 
1805 	return 0;
1806 }
1807 
1808 #endif /* !CONFIG_PPC_PMAC */
1809 
1810 #ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
1811 
1812 static void pmz_console_write(struct console *con, const char *s, unsigned int count);
1813 static int __init pmz_console_setup(struct console *co, char *options);
1814 
1815 static struct console pmz_console = {
1816 	.name	=	PMACZILOG_NAME,
1817 	.write	=	pmz_console_write,
1818 	.device	=	uart_console_device,
1819 	.setup	=	pmz_console_setup,
1820 	.flags	=	CON_PRINTBUFFER,
1821 	.index	=	-1,
1822 	.data   =	&pmz_uart_reg,
1823 };
1824 
1825 #define PMACZILOG_CONSOLE	&pmz_console
1826 #else /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
1827 #define PMACZILOG_CONSOLE	(NULL)
1828 #endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
1829 
1830 /*
1831  * Register the driver, console driver and ports with the serial
1832  * core
1833  */
1834 static int __init pmz_register(void)
1835 {
1836 	pmz_uart_reg.nr = pmz_ports_count;
1837 	pmz_uart_reg.cons = PMACZILOG_CONSOLE;
1838 
1839 	/*
1840 	 * Register this driver with the serial core
1841 	 */
1842 	return uart_register_driver(&pmz_uart_reg);
1843 }
1844 
1845 #ifdef CONFIG_PPC_PMAC
1846 
1847 static struct of_device_id pmz_match[] =
1848 {
1849 	{
1850 	.name		= "ch-a",
1851 	},
1852 	{
1853 	.name		= "ch-b",
1854 	},
1855 	{},
1856 };
1857 MODULE_DEVICE_TABLE (of, pmz_match);
1858 
1859 static struct macio_driver pmz_driver = {
1860 	.driver = {
1861 		.name 		= "pmac_zilog",
1862 		.owner		= THIS_MODULE,
1863 		.of_match_table	= pmz_match,
1864 	},
1865 	.probe		= pmz_attach,
1866 	.remove		= pmz_detach,
1867 	.suspend	= pmz_suspend,
1868 	.resume		= pmz_resume,
1869 };
1870 
1871 #else
1872 
1873 static struct platform_driver pmz_driver = {
1874 	.remove		= __exit_p(pmz_detach),
1875 	.driver		= {
1876 		.name		= "scc",
1877 		.owner		= THIS_MODULE,
1878 	},
1879 };
1880 
1881 #endif /* !CONFIG_PPC_PMAC */
1882 
1883 static int __init init_pmz(void)
1884 {
1885 	int rc, i;
1886 	printk(KERN_INFO "%s\n", version);
1887 
1888 	/*
1889 	 * First, we need to do a direct OF-based probe pass. We
1890 	 * do that because we want serial console up before the
1891 	 * macio stuffs calls us back, and since that makes it
1892 	 * easier to pass the proper number of channels to
1893 	 * uart_register_driver()
1894 	 */
1895 	if (pmz_ports_count == 0)
1896 		pmz_probe();
1897 
1898 	/*
1899 	 * Bail early if no port found
1900 	 */
1901 	if (pmz_ports_count == 0)
1902 		return -ENODEV;
1903 
1904 	/*
1905 	 * Now we register with the serial layer
1906 	 */
1907 	rc = pmz_register();
1908 	if (rc) {
1909 		printk(KERN_ERR
1910 			"pmac_zilog: Error registering serial device, disabling pmac_zilog.\n"
1911 		 	"pmac_zilog: Did another serial driver already claim the minors?\n");
1912 		/* effectively "pmz_unprobe()" */
1913 		for (i=0; i < pmz_ports_count; i++)
1914 			pmz_dispose_port(&pmz_ports[i]);
1915 		return rc;
1916 	}
1917 
1918 	/*
1919 	 * Then we register the macio driver itself
1920 	 */
1921 #ifdef CONFIG_PPC_PMAC
1922 	return macio_register_driver(&pmz_driver);
1923 #else
1924 	return platform_driver_probe(&pmz_driver, pmz_attach);
1925 #endif
1926 }
1927 
1928 static void __exit exit_pmz(void)
1929 {
1930 	int i;
1931 
1932 #ifdef CONFIG_PPC_PMAC
1933 	/* Get rid of macio-driver (detach from macio) */
1934 	macio_unregister_driver(&pmz_driver);
1935 #else
1936 	platform_driver_unregister(&pmz_driver);
1937 #endif
1938 
1939 	for (i = 0; i < pmz_ports_count; i++) {
1940 		struct uart_pmac_port *uport = &pmz_ports[i];
1941 #ifdef CONFIG_PPC_PMAC
1942 		if (uport->node != NULL)
1943 			pmz_dispose_port(uport);
1944 #else
1945 		if (uport->pdev != NULL)
1946 			pmz_dispose_port(uport);
1947 #endif
1948 	}
1949 	/* Unregister UART driver */
1950 	uart_unregister_driver(&pmz_uart_reg);
1951 }
1952 
1953 #ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
1954 
1955 static void pmz_console_putchar(struct uart_port *port, int ch)
1956 {
1957 	struct uart_pmac_port *uap = (struct uart_pmac_port *)port;
1958 
1959 	/* Wait for the transmit buffer to empty. */
1960 	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0)
1961 		udelay(5);
1962 	write_zsdata(uap, ch);
1963 }
1964 
1965 /*
1966  * Print a string to the serial port trying not to disturb
1967  * any possible real use of the port...
1968  */
1969 static void pmz_console_write(struct console *con, const char *s, unsigned int count)
1970 {
1971 	struct uart_pmac_port *uap = &pmz_ports[con->index];
1972 	unsigned long flags;
1973 
1974 	spin_lock_irqsave(&uap->port.lock, flags);
1975 
1976 	/* Turn of interrupts and enable the transmitter. */
1977 	write_zsreg(uap, R1, uap->curregs[1] & ~TxINT_ENAB);
1978 	write_zsreg(uap, R5, uap->curregs[5] | TxENABLE | RTS | DTR);
1979 
1980 	uart_console_write(&uap->port, s, count, pmz_console_putchar);
1981 
1982 	/* Restore the values in the registers. */
1983 	write_zsreg(uap, R1, uap->curregs[1]);
1984 	/* Don't disable the transmitter. */
1985 
1986 	spin_unlock_irqrestore(&uap->port.lock, flags);
1987 }
1988 
1989 /*
1990  * Setup the serial console
1991  */
1992 static int __init pmz_console_setup(struct console *co, char *options)
1993 {
1994 	struct uart_pmac_port *uap;
1995 	struct uart_port *port;
1996 	int baud = 38400;
1997 	int bits = 8;
1998 	int parity = 'n';
1999 	int flow = 'n';
2000 	unsigned long pwr_delay;
2001 
2002 	/*
2003 	 * XServe's default to 57600 bps
2004 	 */
2005 	if (of_machine_is_compatible("RackMac1,1")
2006 	    || of_machine_is_compatible("RackMac1,2")
2007 	    || of_machine_is_compatible("MacRISC4"))
2008 		baud = 57600;
2009 
2010 	/*
2011 	 * Check whether an invalid uart number has been specified, and
2012 	 * if so, search for the first available port that does have
2013 	 * console support.
2014 	 */
2015 	if (co->index >= pmz_ports_count)
2016 		co->index = 0;
2017 	uap = &pmz_ports[co->index];
2018 #ifdef CONFIG_PPC_PMAC
2019 	if (uap->node == NULL)
2020 		return -ENODEV;
2021 #else
2022 	if (uap->pdev == NULL)
2023 		return -ENODEV;
2024 #endif
2025 	port = &uap->port;
2026 
2027 	/*
2028 	 * Mark port as beeing a console
2029 	 */
2030 	uap->flags |= PMACZILOG_FLAG_IS_CONS;
2031 
2032 	/*
2033 	 * Temporary fix for uart layer who didn't setup the spinlock yet
2034 	 */
2035 	spin_lock_init(&port->lock);
2036 
2037 	/*
2038 	 * Enable the hardware
2039 	 */
2040 	pwr_delay = __pmz_startup(uap);
2041 	if (pwr_delay)
2042 		mdelay(pwr_delay);
2043 
2044 	if (options)
2045 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2046 
2047 	return uart_set_options(port, co, baud, parity, bits, flow);
2048 }
2049 
2050 static int __init pmz_console_init(void)
2051 {
2052 	/* Probe ports */
2053 	pmz_probe();
2054 
2055 	if (pmz_ports_count == 0)
2056 		return -ENODEV;
2057 
2058 	/* TODO: Autoprobe console based on OF */
2059 	/* pmz_console.index = i; */
2060 	register_console(&pmz_console);
2061 
2062 	return 0;
2063 
2064 }
2065 console_initcall(pmz_console_init);
2066 #endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
2067 
2068 module_init(init_pmz);
2069 module_exit(exit_pmz);
2070