xref: /openbmc/linux/drivers/tty/serial/pmac_zilog.c (revision 95e9fd10)
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 <asm/sections.h>
61 #include <asm/io.h>
62 #include <asm/irq.h>
63 
64 #ifdef CONFIG_PPC_PMAC
65 #include <asm/prom.h>
66 #include <asm/machdep.h>
67 #include <asm/pmac_feature.h>
68 #include <asm/dbdma.h>
69 #include <asm/macio.h>
70 #else
71 #include <linux/platform_device.h>
72 #define of_machine_is_compatible(x) (0)
73 #endif
74 
75 #if defined (CONFIG_SERIAL_PMACZILOG_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
76 #define SUPPORT_SYSRQ
77 #endif
78 
79 #include <linux/serial.h>
80 #include <linux/serial_core.h>
81 
82 #include "pmac_zilog.h"
83 
84 /* Not yet implemented */
85 #undef HAS_DBDMA
86 
87 static char version[] __initdata = "pmac_zilog: 0.6 (Benjamin Herrenschmidt <benh@kernel.crashing.org>)";
88 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
89 MODULE_DESCRIPTION("Driver for the Mac and PowerMac serial ports.");
90 MODULE_LICENSE("GPL");
91 
92 #ifdef CONFIG_SERIAL_PMACZILOG_TTYS
93 #define PMACZILOG_MAJOR		TTY_MAJOR
94 #define PMACZILOG_MINOR		64
95 #define PMACZILOG_NAME		"ttyS"
96 #else
97 #define PMACZILOG_MAJOR		204
98 #define PMACZILOG_MINOR		192
99 #define PMACZILOG_NAME		"ttyPZ"
100 #endif
101 
102 #define pmz_debug(fmt, arg...)	pr_debug("ttyPZ%d: " fmt, uap->port.line, ## arg)
103 #define pmz_error(fmt, arg...)	pr_err("ttyPZ%d: " fmt, uap->port.line, ## arg)
104 #define pmz_info(fmt, arg...)	pr_info("ttyPZ%d: " fmt, uap->port.line, ## arg)
105 
106 /*
107  * For the sake of early serial console, we can do a pre-probe
108  * (optional) of the ports at rather early boot time.
109  */
110 static struct uart_pmac_port	pmz_ports[MAX_ZS_PORTS];
111 static int			pmz_ports_count;
112 
113 static struct uart_driver pmz_uart_reg = {
114 	.owner		=	THIS_MODULE,
115 	.driver_name	=	PMACZILOG_NAME,
116 	.dev_name	=	PMACZILOG_NAME,
117 	.major		=	PMACZILOG_MAJOR,
118 	.minor		=	PMACZILOG_MINOR,
119 };
120 
121 
122 /*
123  * Load all registers to reprogram the port
124  * This function must only be called when the TX is not busy.  The UART
125  * port lock must be held and local interrupts disabled.
126  */
127 static void pmz_load_zsregs(struct uart_pmac_port *uap, u8 *regs)
128 {
129 	int i;
130 
131 	/* Let pending transmits finish.  */
132 	for (i = 0; i < 1000; i++) {
133 		unsigned char stat = read_zsreg(uap, R1);
134 		if (stat & ALL_SNT)
135 			break;
136 		udelay(100);
137 	}
138 
139 	ZS_CLEARERR(uap);
140 	zssync(uap);
141 	ZS_CLEARFIFO(uap);
142 	zssync(uap);
143 	ZS_CLEARERR(uap);
144 
145 	/* Disable all interrupts.  */
146 	write_zsreg(uap, R1,
147 		    regs[R1] & ~(RxINT_MASK | TxINT_ENAB | EXT_INT_ENAB));
148 
149 	/* Set parity, sync config, stop bits, and clock divisor.  */
150 	write_zsreg(uap, R4, regs[R4]);
151 
152 	/* Set misc. TX/RX control bits.  */
153 	write_zsreg(uap, R10, regs[R10]);
154 
155 	/* Set TX/RX controls sans the enable bits.  */
156 	write_zsreg(uap, R3, regs[R3] & ~RxENABLE);
157 	write_zsreg(uap, R5, regs[R5] & ~TxENABLE);
158 
159 	/* now set R7 "prime" on ESCC */
160 	write_zsreg(uap, R15, regs[R15] | EN85C30);
161 	write_zsreg(uap, R7, regs[R7P]);
162 
163 	/* make sure we use R7 "non-prime" on ESCC */
164 	write_zsreg(uap, R15, regs[R15] & ~EN85C30);
165 
166 	/* Synchronous mode config.  */
167 	write_zsreg(uap, R6, regs[R6]);
168 	write_zsreg(uap, R7, regs[R7]);
169 
170 	/* Disable baud generator.  */
171 	write_zsreg(uap, R14, regs[R14] & ~BRENAB);
172 
173 	/* Clock mode control.  */
174 	write_zsreg(uap, R11, regs[R11]);
175 
176 	/* Lower and upper byte of baud rate generator divisor.  */
177 	write_zsreg(uap, R12, regs[R12]);
178 	write_zsreg(uap, R13, regs[R13]);
179 
180 	/* Now rewrite R14, with BRENAB (if set).  */
181 	write_zsreg(uap, R14, regs[R14]);
182 
183 	/* Reset external status interrupts.  */
184 	write_zsreg(uap, R0, RES_EXT_INT);
185 	write_zsreg(uap, R0, RES_EXT_INT);
186 
187 	/* Rewrite R3/R5, this time without enables masked.  */
188 	write_zsreg(uap, R3, regs[R3]);
189 	write_zsreg(uap, R5, regs[R5]);
190 
191 	/* Rewrite R1, this time without IRQ enabled masked.  */
192 	write_zsreg(uap, R1, regs[R1]);
193 
194 	/* Enable interrupts */
195 	write_zsreg(uap, R9, regs[R9]);
196 }
197 
198 /*
199  * We do like sunzilog to avoid disrupting pending Tx
200  * Reprogram the Zilog channel HW registers with the copies found in the
201  * software state struct.  If the transmitter is busy, we defer this update
202  * until the next TX complete interrupt.  Else, we do it right now.
203  *
204  * The UART port lock must be held and local interrupts disabled.
205  */
206 static void pmz_maybe_update_regs(struct uart_pmac_port *uap)
207 {
208 	if (!ZS_REGS_HELD(uap)) {
209 		if (ZS_TX_ACTIVE(uap)) {
210 			uap->flags |= PMACZILOG_FLAG_REGS_HELD;
211 		} else {
212 			pmz_debug("pmz: maybe_update_regs: updating\n");
213 			pmz_load_zsregs(uap, uap->curregs);
214 		}
215 	}
216 }
217 
218 static void pmz_interrupt_control(struct uart_pmac_port *uap, int enable)
219 {
220 	if (enable) {
221 		uap->curregs[1] |= INT_ALL_Rx | TxINT_ENAB;
222 		if (!ZS_IS_EXTCLK(uap))
223 			uap->curregs[1] |= EXT_INT_ENAB;
224 	} else {
225 		uap->curregs[1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
226 	}
227 	write_zsreg(uap, R1, uap->curregs[1]);
228 }
229 
230 static struct tty_struct *pmz_receive_chars(struct uart_pmac_port *uap)
231 {
232 	struct tty_struct *tty = NULL;
233 	unsigned char ch, r1, drop, error, flag;
234 	int loops = 0;
235 
236 	/* Sanity check, make sure the old bug is no longer happening */
237 	if (uap->port.state == NULL || uap->port.state->port.tty == NULL) {
238 		WARN_ON(1);
239 		(void)read_zsdata(uap);
240 		return NULL;
241 	}
242 	tty = uap->port.state->port.tty;
243 
244 	while (1) {
245 		error = 0;
246 		drop = 0;
247 
248 		r1 = read_zsreg(uap, R1);
249 		ch = read_zsdata(uap);
250 
251 		if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR)) {
252 			write_zsreg(uap, R0, ERR_RES);
253 			zssync(uap);
254 		}
255 
256 		ch &= uap->parity_mask;
257 		if (ch == 0 && uap->flags & PMACZILOG_FLAG_BREAK) {
258 			uap->flags &= ~PMACZILOG_FLAG_BREAK;
259 		}
260 
261 #if defined(CONFIG_MAGIC_SYSRQ) && defined(CONFIG_SERIAL_CORE_CONSOLE)
262 #ifdef USE_CTRL_O_SYSRQ
263 		/* Handle the SysRq ^O Hack */
264 		if (ch == '\x0f') {
265 			uap->port.sysrq = jiffies + HZ*5;
266 			goto next_char;
267 		}
268 #endif /* USE_CTRL_O_SYSRQ */
269 		if (uap->port.sysrq) {
270 			int swallow;
271 			spin_unlock(&uap->port.lock);
272 			swallow = uart_handle_sysrq_char(&uap->port, ch);
273 			spin_lock(&uap->port.lock);
274 			if (swallow)
275 				goto next_char;
276 		}
277 #endif /* CONFIG_MAGIC_SYSRQ && CONFIG_SERIAL_CORE_CONSOLE */
278 
279 		/* A real serial line, record the character and status.  */
280 		if (drop)
281 			goto next_char;
282 
283 		flag = TTY_NORMAL;
284 		uap->port.icount.rx++;
285 
286 		if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR | BRK_ABRT)) {
287 			error = 1;
288 			if (r1 & BRK_ABRT) {
289 				pmz_debug("pmz: got break !\n");
290 				r1 &= ~(PAR_ERR | CRC_ERR);
291 				uap->port.icount.brk++;
292 				if (uart_handle_break(&uap->port))
293 					goto next_char;
294 			}
295 			else if (r1 & PAR_ERR)
296 				uap->port.icount.parity++;
297 			else if (r1 & CRC_ERR)
298 				uap->port.icount.frame++;
299 			if (r1 & Rx_OVR)
300 				uap->port.icount.overrun++;
301 			r1 &= uap->port.read_status_mask;
302 			if (r1 & BRK_ABRT)
303 				flag = TTY_BREAK;
304 			else if (r1 & PAR_ERR)
305 				flag = TTY_PARITY;
306 			else if (r1 & CRC_ERR)
307 				flag = TTY_FRAME;
308 		}
309 
310 		if (uap->port.ignore_status_mask == 0xff ||
311 		    (r1 & uap->port.ignore_status_mask) == 0) {
312 			tty_insert_flip_char(tty, ch, flag);
313 		}
314 		if (r1 & Rx_OVR)
315 			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
316 	next_char:
317 		/* We can get stuck in an infinite loop getting char 0 when the
318 		 * line is in a wrong HW state, we break that here.
319 		 * When that happens, I disable the receive side of the driver.
320 		 * Note that what I've been experiencing is a real irq loop where
321 		 * I'm getting flooded regardless of the actual port speed.
322 		 * Something strange is going on with the HW
323 		 */
324 		if ((++loops) > 1000)
325 			goto flood;
326 		ch = read_zsreg(uap, R0);
327 		if (!(ch & Rx_CH_AV))
328 			break;
329 	}
330 
331 	return tty;
332  flood:
333 	pmz_interrupt_control(uap, 0);
334 	pmz_error("pmz: rx irq flood !\n");
335 	return tty;
336 }
337 
338 static void pmz_status_handle(struct uart_pmac_port *uap)
339 {
340 	unsigned char status;
341 
342 	status = read_zsreg(uap, R0);
343 	write_zsreg(uap, R0, RES_EXT_INT);
344 	zssync(uap);
345 
346 	if (ZS_IS_OPEN(uap) && ZS_WANTS_MODEM_STATUS(uap)) {
347 		if (status & SYNC_HUNT)
348 			uap->port.icount.dsr++;
349 
350 		/* The Zilog just gives us an interrupt when DCD/CTS/etc. change.
351 		 * But it does not tell us which bit has changed, we have to keep
352 		 * track of this ourselves.
353 		 * The CTS input is inverted for some reason.  -- paulus
354 		 */
355 		if ((status ^ uap->prev_status) & DCD)
356 			uart_handle_dcd_change(&uap->port,
357 					       (status & DCD));
358 		if ((status ^ uap->prev_status) & CTS)
359 			uart_handle_cts_change(&uap->port,
360 					       !(status & CTS));
361 
362 		wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
363 	}
364 
365 	if (status & BRK_ABRT)
366 		uap->flags |= PMACZILOG_FLAG_BREAK;
367 
368 	uap->prev_status = status;
369 }
370 
371 static void pmz_transmit_chars(struct uart_pmac_port *uap)
372 {
373 	struct circ_buf *xmit;
374 
375 	if (ZS_IS_CONS(uap)) {
376 		unsigned char status = read_zsreg(uap, R0);
377 
378 		/* TX still busy?  Just wait for the next TX done interrupt.
379 		 *
380 		 * It can occur because of how we do serial console writes.  It would
381 		 * be nice to transmit console writes just like we normally would for
382 		 * a TTY line. (ie. buffered and TX interrupt driven).  That is not
383 		 * easy because console writes cannot sleep.  One solution might be
384 		 * to poll on enough port->xmit space becoming free.  -DaveM
385 		 */
386 		if (!(status & Tx_BUF_EMP))
387 			return;
388 	}
389 
390 	uap->flags &= ~PMACZILOG_FLAG_TX_ACTIVE;
391 
392 	if (ZS_REGS_HELD(uap)) {
393 		pmz_load_zsregs(uap, uap->curregs);
394 		uap->flags &= ~PMACZILOG_FLAG_REGS_HELD;
395 	}
396 
397 	if (ZS_TX_STOPPED(uap)) {
398 		uap->flags &= ~PMACZILOG_FLAG_TX_STOPPED;
399 		goto ack_tx_int;
400 	}
401 
402 	/* Under some circumstances, we see interrupts reported for
403 	 * a closed channel. The interrupt mask in R1 is clear, but
404 	 * R3 still signals the interrupts and we see them when taking
405 	 * an interrupt for the other channel (this could be a qemu
406 	 * bug but since the ESCC doc doesn't specify precsiely whether
407 	 * R3 interrup status bits are masked by R1 interrupt enable
408 	 * bits, better safe than sorry). --BenH.
409 	 */
410 	if (!ZS_IS_OPEN(uap))
411 		goto ack_tx_int;
412 
413 	if (uap->port.x_char) {
414 		uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
415 		write_zsdata(uap, uap->port.x_char);
416 		zssync(uap);
417 		uap->port.icount.tx++;
418 		uap->port.x_char = 0;
419 		return;
420 	}
421 
422 	if (uap->port.state == NULL)
423 		goto ack_tx_int;
424 	xmit = &uap->port.state->xmit;
425 	if (uart_circ_empty(xmit)) {
426 		uart_write_wakeup(&uap->port);
427 		goto ack_tx_int;
428 	}
429 	if (uart_tx_stopped(&uap->port))
430 		goto ack_tx_int;
431 
432 	uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
433 	write_zsdata(uap, xmit->buf[xmit->tail]);
434 	zssync(uap);
435 
436 	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
437 	uap->port.icount.tx++;
438 
439 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
440 		uart_write_wakeup(&uap->port);
441 
442 	return;
443 
444 ack_tx_int:
445 	write_zsreg(uap, R0, RES_Tx_P);
446 	zssync(uap);
447 }
448 
449 /* Hrm... we register that twice, fixme later.... */
450 static irqreturn_t pmz_interrupt(int irq, void *dev_id)
451 {
452 	struct uart_pmac_port *uap = dev_id;
453 	struct uart_pmac_port *uap_a;
454 	struct uart_pmac_port *uap_b;
455 	int rc = IRQ_NONE;
456 	struct tty_struct *tty;
457 	u8 r3;
458 
459 	uap_a = pmz_get_port_A(uap);
460 	uap_b = uap_a->mate;
461 
462 	spin_lock(&uap_a->port.lock);
463 	r3 = read_zsreg(uap_a, R3);
464 
465 #ifdef DEBUG_HARD
466 	pmz_debug("irq, r3: %x\n", r3);
467 #endif
468 	/* Channel A */
469 	tty = NULL;
470 	if (r3 & (CHAEXT | CHATxIP | CHARxIP)) {
471 		if (!ZS_IS_OPEN(uap_a)) {
472 			pmz_debug("ChanA interrupt while not open !\n");
473 			goto skip_a;
474 		}
475 		write_zsreg(uap_a, R0, RES_H_IUS);
476 		zssync(uap_a);
477 		if (r3 & CHAEXT)
478 			pmz_status_handle(uap_a);
479 		if (r3 & CHARxIP)
480 			tty = pmz_receive_chars(uap_a);
481 		if (r3 & CHATxIP)
482 			pmz_transmit_chars(uap_a);
483 		rc = IRQ_HANDLED;
484 	}
485  skip_a:
486 	spin_unlock(&uap_a->port.lock);
487 	if (tty != NULL)
488 		tty_flip_buffer_push(tty);
489 
490 	if (!uap_b)
491 		goto out;
492 
493 	spin_lock(&uap_b->port.lock);
494 	tty = NULL;
495 	if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) {
496 		if (!ZS_IS_OPEN(uap_b)) {
497 			pmz_debug("ChanB interrupt while not open !\n");
498 			goto skip_b;
499 		}
500 		write_zsreg(uap_b, R0, RES_H_IUS);
501 		zssync(uap_b);
502 		if (r3 & CHBEXT)
503 			pmz_status_handle(uap_b);
504 		if (r3 & CHBRxIP)
505 			tty = pmz_receive_chars(uap_b);
506 		if (r3 & CHBTxIP)
507 			pmz_transmit_chars(uap_b);
508 		rc = IRQ_HANDLED;
509 	}
510  skip_b:
511 	spin_unlock(&uap_b->port.lock);
512 	if (tty != NULL)
513 		tty_flip_buffer_push(tty);
514 
515  out:
516 	return rc;
517 }
518 
519 /*
520  * Peek the status register, lock not held by caller
521  */
522 static inline u8 pmz_peek_status(struct uart_pmac_port *uap)
523 {
524 	unsigned long flags;
525 	u8 status;
526 
527 	spin_lock_irqsave(&uap->port.lock, flags);
528 	status = read_zsreg(uap, R0);
529 	spin_unlock_irqrestore(&uap->port.lock, flags);
530 
531 	return status;
532 }
533 
534 /*
535  * Check if transmitter is empty
536  * The port lock is not held.
537  */
538 static unsigned int pmz_tx_empty(struct uart_port *port)
539 {
540 	unsigned char status;
541 
542 	status = pmz_peek_status(to_pmz(port));
543 	if (status & Tx_BUF_EMP)
544 		return TIOCSER_TEMT;
545 	return 0;
546 }
547 
548 /*
549  * Set Modem Control (RTS & DTR) bits
550  * The port lock is held and interrupts are disabled.
551  * Note: Shall we really filter out RTS on external ports or
552  * should that be dealt at higher level only ?
553  */
554 static void pmz_set_mctrl(struct uart_port *port, unsigned int mctrl)
555 {
556 	struct uart_pmac_port *uap = to_pmz(port);
557 	unsigned char set_bits, clear_bits;
558 
559         /* Do nothing for irda for now... */
560 	if (ZS_IS_IRDA(uap))
561 		return;
562 	/* We get called during boot with a port not up yet */
563 	if (!(ZS_IS_OPEN(uap) || ZS_IS_CONS(uap)))
564 		return;
565 
566 	set_bits = clear_bits = 0;
567 
568 	if (ZS_IS_INTMODEM(uap)) {
569 		if (mctrl & TIOCM_RTS)
570 			set_bits |= RTS;
571 		else
572 			clear_bits |= RTS;
573 	}
574 	if (mctrl & TIOCM_DTR)
575 		set_bits |= DTR;
576 	else
577 		clear_bits |= DTR;
578 
579 	/* NOTE: Not subject to 'transmitter active' rule.  */
580 	uap->curregs[R5] |= set_bits;
581 	uap->curregs[R5] &= ~clear_bits;
582 
583 	write_zsreg(uap, R5, uap->curregs[R5]);
584 	pmz_debug("pmz_set_mctrl: set bits: %x, clear bits: %x -> %x\n",
585 		  set_bits, clear_bits, uap->curregs[R5]);
586 	zssync(uap);
587 }
588 
589 /*
590  * Get Modem Control bits (only the input ones, the core will
591  * or that with a cached value of the control ones)
592  * The port lock is held and interrupts are disabled.
593  */
594 static unsigned int pmz_get_mctrl(struct uart_port *port)
595 {
596 	struct uart_pmac_port *uap = to_pmz(port);
597 	unsigned char status;
598 	unsigned int ret;
599 
600 	status = read_zsreg(uap, R0);
601 
602 	ret = 0;
603 	if (status & DCD)
604 		ret |= TIOCM_CAR;
605 	if (status & SYNC_HUNT)
606 		ret |= TIOCM_DSR;
607 	if (!(status & CTS))
608 		ret |= TIOCM_CTS;
609 
610 	return ret;
611 }
612 
613 /*
614  * Stop TX side. Dealt like sunzilog at next Tx interrupt,
615  * though for DMA, we will have to do a bit more.
616  * The port lock is held and interrupts are disabled.
617  */
618 static void pmz_stop_tx(struct uart_port *port)
619 {
620 	to_pmz(port)->flags |= PMACZILOG_FLAG_TX_STOPPED;
621 }
622 
623 /*
624  * Kick the Tx side.
625  * The port lock is held and interrupts are disabled.
626  */
627 static void pmz_start_tx(struct uart_port *port)
628 {
629 	struct uart_pmac_port *uap = to_pmz(port);
630 	unsigned char status;
631 
632 	pmz_debug("pmz: start_tx()\n");
633 
634 	uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
635 	uap->flags &= ~PMACZILOG_FLAG_TX_STOPPED;
636 
637 	status = read_zsreg(uap, R0);
638 
639 	/* TX busy?  Just wait for the TX done interrupt.  */
640 	if (!(status & Tx_BUF_EMP))
641 		return;
642 
643 	/* Send the first character to jump-start the TX done
644 	 * IRQ sending engine.
645 	 */
646 	if (port->x_char) {
647 		write_zsdata(uap, port->x_char);
648 		zssync(uap);
649 		port->icount.tx++;
650 		port->x_char = 0;
651 	} else {
652 		struct circ_buf *xmit = &port->state->xmit;
653 
654 		write_zsdata(uap, xmit->buf[xmit->tail]);
655 		zssync(uap);
656 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
657 		port->icount.tx++;
658 
659 		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
660 			uart_write_wakeup(&uap->port);
661 	}
662 	pmz_debug("pmz: start_tx() done.\n");
663 }
664 
665 /*
666  * Stop Rx side, basically disable emitting of
667  * Rx interrupts on the port. We don't disable the rx
668  * side of the chip proper though
669  * The port lock is held.
670  */
671 static void pmz_stop_rx(struct uart_port *port)
672 {
673 	struct uart_pmac_port *uap = to_pmz(port);
674 
675 	pmz_debug("pmz: stop_rx()()\n");
676 
677 	/* Disable all RX interrupts.  */
678 	uap->curregs[R1] &= ~RxINT_MASK;
679 	pmz_maybe_update_regs(uap);
680 
681 	pmz_debug("pmz: stop_rx() done.\n");
682 }
683 
684 /*
685  * Enable modem status change interrupts
686  * The port lock is held.
687  */
688 static void pmz_enable_ms(struct uart_port *port)
689 {
690 	struct uart_pmac_port *uap = to_pmz(port);
691 	unsigned char new_reg;
692 
693 	if (ZS_IS_IRDA(uap))
694 		return;
695 	new_reg = uap->curregs[R15] | (DCDIE | SYNCIE | CTSIE);
696 	if (new_reg != uap->curregs[R15]) {
697 		uap->curregs[R15] = new_reg;
698 
699 		/* NOTE: Not subject to 'transmitter active' rule. */
700 		write_zsreg(uap, R15, uap->curregs[R15]);
701 	}
702 }
703 
704 /*
705  * Control break state emission
706  * The port lock is not held.
707  */
708 static void pmz_break_ctl(struct uart_port *port, int break_state)
709 {
710 	struct uart_pmac_port *uap = to_pmz(port);
711 	unsigned char set_bits, clear_bits, new_reg;
712 	unsigned long flags;
713 
714 	set_bits = clear_bits = 0;
715 
716 	if (break_state)
717 		set_bits |= SND_BRK;
718 	else
719 		clear_bits |= SND_BRK;
720 
721 	spin_lock_irqsave(&port->lock, flags);
722 
723 	new_reg = (uap->curregs[R5] | set_bits) & ~clear_bits;
724 	if (new_reg != uap->curregs[R5]) {
725 		uap->curregs[R5] = new_reg;
726 		write_zsreg(uap, R5, uap->curregs[R5]);
727 	}
728 
729 	spin_unlock_irqrestore(&port->lock, flags);
730 }
731 
732 #ifdef CONFIG_PPC_PMAC
733 
734 /*
735  * Turn power on or off to the SCC and associated stuff
736  * (port drivers, modem, IR port, etc.)
737  * Returns the number of milliseconds we should wait before
738  * trying to use the port.
739  */
740 static int pmz_set_scc_power(struct uart_pmac_port *uap, int state)
741 {
742 	int delay = 0;
743 	int rc;
744 
745 	if (state) {
746 		rc = pmac_call_feature(
747 			PMAC_FTR_SCC_ENABLE, uap->node, uap->port_type, 1);
748 		pmz_debug("port power on result: %d\n", rc);
749 		if (ZS_IS_INTMODEM(uap)) {
750 			rc = pmac_call_feature(
751 				PMAC_FTR_MODEM_ENABLE, uap->node, 0, 1);
752 			delay = 2500;	/* wait for 2.5s before using */
753 			pmz_debug("modem power result: %d\n", rc);
754 		}
755 	} else {
756 		/* TODO: Make that depend on a timer, don't power down
757 		 * immediately
758 		 */
759 		if (ZS_IS_INTMODEM(uap)) {
760 			rc = pmac_call_feature(
761 				PMAC_FTR_MODEM_ENABLE, uap->node, 0, 0);
762 			pmz_debug("port power off result: %d\n", rc);
763 		}
764 		pmac_call_feature(PMAC_FTR_SCC_ENABLE, uap->node, uap->port_type, 0);
765 	}
766 	return delay;
767 }
768 
769 #else
770 
771 static int pmz_set_scc_power(struct uart_pmac_port *uap, int state)
772 {
773 	return 0;
774 }
775 
776 #endif /* !CONFIG_PPC_PMAC */
777 
778 /*
779  * FixZeroBug....Works around a bug in the SCC receiving channel.
780  * Inspired from Darwin code, 15 Sept. 2000  -DanM
781  *
782  * The following sequence prevents a problem that is seen with O'Hare ASICs
783  * (most versions -- also with some Heathrow and Hydra ASICs) where a zero
784  * at the input to the receiver becomes 'stuck' and locks up the receiver.
785  * This problem can occur as a result of a zero bit at the receiver input
786  * coincident with any of the following events:
787  *
788  *	The SCC is initialized (hardware or software).
789  *	A framing error is detected.
790  *	The clocking option changes from synchronous or X1 asynchronous
791  *		clocking to X16, X32, or X64 asynchronous clocking.
792  *	The decoding mode is changed among NRZ, NRZI, FM0, or FM1.
793  *
794  * This workaround attempts to recover from the lockup condition by placing
795  * the SCC in synchronous loopback mode with a fast clock before programming
796  * any of the asynchronous modes.
797  */
798 static void pmz_fix_zero_bug_scc(struct uart_pmac_port *uap)
799 {
800 	write_zsreg(uap, 9, ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB);
801 	zssync(uap);
802 	udelay(10);
803 	write_zsreg(uap, 9, (ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB) | NV);
804 	zssync(uap);
805 
806 	write_zsreg(uap, 4, X1CLK | MONSYNC);
807 	write_zsreg(uap, 3, Rx8);
808 	write_zsreg(uap, 5, Tx8 | RTS);
809 	write_zsreg(uap, 9, NV);	/* Didn't we already do this? */
810 	write_zsreg(uap, 11, RCBR | TCBR);
811 	write_zsreg(uap, 12, 0);
812 	write_zsreg(uap, 13, 0);
813 	write_zsreg(uap, 14, (LOOPBAK | BRSRC));
814 	write_zsreg(uap, 14, (LOOPBAK | BRSRC | BRENAB));
815 	write_zsreg(uap, 3, Rx8 | RxENABLE);
816 	write_zsreg(uap, 0, RES_EXT_INT);
817 	write_zsreg(uap, 0, RES_EXT_INT);
818 	write_zsreg(uap, 0, RES_EXT_INT);	/* to kill some time */
819 
820 	/* The channel should be OK now, but it is probably receiving
821 	 * loopback garbage.
822 	 * Switch to asynchronous mode, disable the receiver,
823 	 * and discard everything in the receive buffer.
824 	 */
825 	write_zsreg(uap, 9, NV);
826 	write_zsreg(uap, 4, X16CLK | SB_MASK);
827 	write_zsreg(uap, 3, Rx8);
828 
829 	while (read_zsreg(uap, 0) & Rx_CH_AV) {
830 		(void)read_zsreg(uap, 8);
831 		write_zsreg(uap, 0, RES_EXT_INT);
832 		write_zsreg(uap, 0, ERR_RES);
833 	}
834 }
835 
836 /*
837  * Real startup routine, powers up the hardware and sets up
838  * the SCC. Returns a delay in ms where you need to wait before
839  * actually using the port, this is typically the internal modem
840  * powerup delay. This routine expect the lock to be taken.
841  */
842 static int __pmz_startup(struct uart_pmac_port *uap)
843 {
844 	int pwr_delay = 0;
845 
846 	memset(&uap->curregs, 0, sizeof(uap->curregs));
847 
848 	/* Power up the SCC & underlying hardware (modem/irda) */
849 	pwr_delay = pmz_set_scc_power(uap, 1);
850 
851 	/* Nice buggy HW ... */
852 	pmz_fix_zero_bug_scc(uap);
853 
854 	/* Reset the channel */
855 	uap->curregs[R9] = 0;
856 	write_zsreg(uap, 9, ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB);
857 	zssync(uap);
858 	udelay(10);
859 	write_zsreg(uap, 9, 0);
860 	zssync(uap);
861 
862 	/* Clear the interrupt registers */
863 	write_zsreg(uap, R1, 0);
864 	write_zsreg(uap, R0, ERR_RES);
865 	write_zsreg(uap, R0, ERR_RES);
866 	write_zsreg(uap, R0, RES_H_IUS);
867 	write_zsreg(uap, R0, RES_H_IUS);
868 
869 	/* Setup some valid baud rate */
870 	uap->curregs[R4] = X16CLK | SB1;
871 	uap->curregs[R3] = Rx8;
872 	uap->curregs[R5] = Tx8 | RTS;
873 	if (!ZS_IS_IRDA(uap))
874 		uap->curregs[R5] |= DTR;
875 	uap->curregs[R12] = 0;
876 	uap->curregs[R13] = 0;
877 	uap->curregs[R14] = BRENAB;
878 
879 	/* Clear handshaking, enable BREAK interrupts */
880 	uap->curregs[R15] = BRKIE;
881 
882 	/* Master interrupt enable */
883 	uap->curregs[R9] |= NV | MIE;
884 
885 	pmz_load_zsregs(uap, uap->curregs);
886 
887 	/* Enable receiver and transmitter.  */
888 	write_zsreg(uap, R3, uap->curregs[R3] |= RxENABLE);
889 	write_zsreg(uap, R5, uap->curregs[R5] |= TxENABLE);
890 
891 	/* Remember status for DCD/CTS changes */
892 	uap->prev_status = read_zsreg(uap, R0);
893 
894 	return pwr_delay;
895 }
896 
897 static void pmz_irda_reset(struct uart_pmac_port *uap)
898 {
899 	unsigned long flags;
900 
901 	spin_lock_irqsave(&uap->port.lock, flags);
902 	uap->curregs[R5] |= DTR;
903 	write_zsreg(uap, R5, uap->curregs[R5]);
904 	zssync(uap);
905 	spin_unlock_irqrestore(&uap->port.lock, flags);
906 	msleep(110);
907 
908 	spin_lock_irqsave(&uap->port.lock, flags);
909 	uap->curregs[R5] &= ~DTR;
910 	write_zsreg(uap, R5, uap->curregs[R5]);
911 	zssync(uap);
912 	spin_unlock_irqrestore(&uap->port.lock, flags);
913 	msleep(10);
914 }
915 
916 /*
917  * This is the "normal" startup routine, using the above one
918  * wrapped with the lock and doing a schedule delay
919  */
920 static int pmz_startup(struct uart_port *port)
921 {
922 	struct uart_pmac_port *uap = to_pmz(port);
923 	unsigned long flags;
924 	int pwr_delay = 0;
925 
926 	pmz_debug("pmz: startup()\n");
927 
928 	uap->flags |= PMACZILOG_FLAG_IS_OPEN;
929 
930 	/* A console is never powered down. Else, power up and
931 	 * initialize the chip
932 	 */
933 	if (!ZS_IS_CONS(uap)) {
934 		spin_lock_irqsave(&port->lock, flags);
935 		pwr_delay = __pmz_startup(uap);
936 		spin_unlock_irqrestore(&port->lock, flags);
937 	}
938 	sprintf(uap->irq_name, PMACZILOG_NAME"%d", uap->port.line);
939 	if (request_irq(uap->port.irq, pmz_interrupt, IRQF_SHARED,
940 			uap->irq_name, uap)) {
941 		pmz_error("Unable to register zs interrupt handler.\n");
942 		pmz_set_scc_power(uap, 0);
943 		return -ENXIO;
944 	}
945 
946 	/* Right now, we deal with delay by blocking here, I'll be
947 	 * smarter later on
948 	 */
949 	if (pwr_delay != 0) {
950 		pmz_debug("pmz: delaying %d ms\n", pwr_delay);
951 		msleep(pwr_delay);
952 	}
953 
954 	/* IrDA reset is done now */
955 	if (ZS_IS_IRDA(uap))
956 		pmz_irda_reset(uap);
957 
958 	/* Enable interrupt requests for the channel */
959 	spin_lock_irqsave(&port->lock, flags);
960 	pmz_interrupt_control(uap, 1);
961 	spin_unlock_irqrestore(&port->lock, flags);
962 
963 	pmz_debug("pmz: startup() done.\n");
964 
965 	return 0;
966 }
967 
968 static void pmz_shutdown(struct uart_port *port)
969 {
970 	struct uart_pmac_port *uap = to_pmz(port);
971 	unsigned long flags;
972 
973 	pmz_debug("pmz: shutdown()\n");
974 
975 	spin_lock_irqsave(&port->lock, flags);
976 
977 	/* Disable interrupt requests for the channel */
978 	pmz_interrupt_control(uap, 0);
979 
980 	if (!ZS_IS_CONS(uap)) {
981 		/* Disable receiver and transmitter */
982 		uap->curregs[R3] &= ~RxENABLE;
983 		uap->curregs[R5] &= ~TxENABLE;
984 
985 		/* Disable break assertion */
986 		uap->curregs[R5] &= ~SND_BRK;
987 		pmz_maybe_update_regs(uap);
988 	}
989 
990 	spin_unlock_irqrestore(&port->lock, flags);
991 
992 	/* Release interrupt handler */
993 	free_irq(uap->port.irq, uap);
994 
995 	spin_lock_irqsave(&port->lock, flags);
996 
997 	uap->flags &= ~PMACZILOG_FLAG_IS_OPEN;
998 
999 	if (!ZS_IS_CONS(uap))
1000 		pmz_set_scc_power(uap, 0);	/* Shut the chip down */
1001 
1002 	spin_unlock_irqrestore(&port->lock, flags);
1003 
1004 	pmz_debug("pmz: shutdown() done.\n");
1005 }
1006 
1007 /* Shared by TTY driver and serial console setup.  The port lock is held
1008  * and local interrupts are disabled.
1009  */
1010 static void pmz_convert_to_zs(struct uart_pmac_port *uap, unsigned int cflag,
1011 			      unsigned int iflag, unsigned long baud)
1012 {
1013 	int brg;
1014 
1015 	/* Switch to external clocking for IrDA high clock rates. That
1016 	 * code could be re-used for Midi interfaces with different
1017 	 * multipliers
1018 	 */
1019 	if (baud >= 115200 && ZS_IS_IRDA(uap)) {
1020 		uap->curregs[R4] = X1CLK;
1021 		uap->curregs[R11] = RCTRxCP | TCTRxCP;
1022 		uap->curregs[R14] = 0; /* BRG off */
1023 		uap->curregs[R12] = 0;
1024 		uap->curregs[R13] = 0;
1025 		uap->flags |= PMACZILOG_FLAG_IS_EXTCLK;
1026 	} else {
1027 		switch (baud) {
1028 		case ZS_CLOCK/16:	/* 230400 */
1029 			uap->curregs[R4] = X16CLK;
1030 			uap->curregs[R11] = 0;
1031 			uap->curregs[R14] = 0;
1032 			break;
1033 		case ZS_CLOCK/32:	/* 115200 */
1034 			uap->curregs[R4] = X32CLK;
1035 			uap->curregs[R11] = 0;
1036 			uap->curregs[R14] = 0;
1037 			break;
1038 		default:
1039 			uap->curregs[R4] = X16CLK;
1040 			uap->curregs[R11] = TCBR | RCBR;
1041 			brg = BPS_TO_BRG(baud, ZS_CLOCK / 16);
1042 			uap->curregs[R12] = (brg & 255);
1043 			uap->curregs[R13] = ((brg >> 8) & 255);
1044 			uap->curregs[R14] = BRENAB;
1045 		}
1046 		uap->flags &= ~PMACZILOG_FLAG_IS_EXTCLK;
1047 	}
1048 
1049 	/* Character size, stop bits, and parity. */
1050 	uap->curregs[3] &= ~RxN_MASK;
1051 	uap->curregs[5] &= ~TxN_MASK;
1052 
1053 	switch (cflag & CSIZE) {
1054 	case CS5:
1055 		uap->curregs[3] |= Rx5;
1056 		uap->curregs[5] |= Tx5;
1057 		uap->parity_mask = 0x1f;
1058 		break;
1059 	case CS6:
1060 		uap->curregs[3] |= Rx6;
1061 		uap->curregs[5] |= Tx6;
1062 		uap->parity_mask = 0x3f;
1063 		break;
1064 	case CS7:
1065 		uap->curregs[3] |= Rx7;
1066 		uap->curregs[5] |= Tx7;
1067 		uap->parity_mask = 0x7f;
1068 		break;
1069 	case CS8:
1070 	default:
1071 		uap->curregs[3] |= Rx8;
1072 		uap->curregs[5] |= Tx8;
1073 		uap->parity_mask = 0xff;
1074 		break;
1075 	};
1076 	uap->curregs[4] &= ~(SB_MASK);
1077 	if (cflag & CSTOPB)
1078 		uap->curregs[4] |= SB2;
1079 	else
1080 		uap->curregs[4] |= SB1;
1081 	if (cflag & PARENB)
1082 		uap->curregs[4] |= PAR_ENAB;
1083 	else
1084 		uap->curregs[4] &= ~PAR_ENAB;
1085 	if (!(cflag & PARODD))
1086 		uap->curregs[4] |= PAR_EVEN;
1087 	else
1088 		uap->curregs[4] &= ~PAR_EVEN;
1089 
1090 	uap->port.read_status_mask = Rx_OVR;
1091 	if (iflag & INPCK)
1092 		uap->port.read_status_mask |= CRC_ERR | PAR_ERR;
1093 	if (iflag & (BRKINT | PARMRK))
1094 		uap->port.read_status_mask |= BRK_ABRT;
1095 
1096 	uap->port.ignore_status_mask = 0;
1097 	if (iflag & IGNPAR)
1098 		uap->port.ignore_status_mask |= CRC_ERR | PAR_ERR;
1099 	if (iflag & IGNBRK) {
1100 		uap->port.ignore_status_mask |= BRK_ABRT;
1101 		if (iflag & IGNPAR)
1102 			uap->port.ignore_status_mask |= Rx_OVR;
1103 	}
1104 
1105 	if ((cflag & CREAD) == 0)
1106 		uap->port.ignore_status_mask = 0xff;
1107 }
1108 
1109 
1110 /*
1111  * Set the irda codec on the imac to the specified baud rate.
1112  */
1113 static void pmz_irda_setup(struct uart_pmac_port *uap, unsigned long *baud)
1114 {
1115 	u8 cmdbyte;
1116 	int t, version;
1117 
1118 	switch (*baud) {
1119 	/* SIR modes */
1120 	case 2400:
1121 		cmdbyte = 0x53;
1122 		break;
1123 	case 4800:
1124 		cmdbyte = 0x52;
1125 		break;
1126 	case 9600:
1127 		cmdbyte = 0x51;
1128 		break;
1129 	case 19200:
1130 		cmdbyte = 0x50;
1131 		break;
1132 	case 38400:
1133 		cmdbyte = 0x4f;
1134 		break;
1135 	case 57600:
1136 		cmdbyte = 0x4e;
1137 		break;
1138 	case 115200:
1139 		cmdbyte = 0x4d;
1140 		break;
1141 	/* The FIR modes aren't really supported at this point, how
1142 	 * do we select the speed ? via the FCR on KeyLargo ?
1143 	 */
1144 	case 1152000:
1145 		cmdbyte = 0;
1146 		break;
1147 	case 4000000:
1148 		cmdbyte = 0;
1149 		break;
1150 	default: /* 9600 */
1151 		cmdbyte = 0x51;
1152 		*baud = 9600;
1153 		break;
1154 	}
1155 
1156 	/* Wait for transmitter to drain */
1157 	t = 10000;
1158 	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0
1159 	       || (read_zsreg(uap, R1) & ALL_SNT) == 0) {
1160 		if (--t <= 0) {
1161 			pmz_error("transmitter didn't drain\n");
1162 			return;
1163 		}
1164 		udelay(10);
1165 	}
1166 
1167 	/* Drain the receiver too */
1168 	t = 100;
1169 	(void)read_zsdata(uap);
1170 	(void)read_zsdata(uap);
1171 	(void)read_zsdata(uap);
1172 	mdelay(10);
1173 	while (read_zsreg(uap, R0) & Rx_CH_AV) {
1174 		read_zsdata(uap);
1175 		mdelay(10);
1176 		if (--t <= 0) {
1177 			pmz_error("receiver didn't drain\n");
1178 			return;
1179 		}
1180 	}
1181 
1182 	/* Switch to command mode */
1183 	uap->curregs[R5] |= DTR;
1184 	write_zsreg(uap, R5, uap->curregs[R5]);
1185 	zssync(uap);
1186 	mdelay(1);
1187 
1188 	/* Switch SCC to 19200 */
1189 	pmz_convert_to_zs(uap, CS8, 0, 19200);
1190 	pmz_load_zsregs(uap, uap->curregs);
1191 	mdelay(1);
1192 
1193 	/* Write get_version command byte */
1194 	write_zsdata(uap, 1);
1195 	t = 5000;
1196 	while ((read_zsreg(uap, R0) & Rx_CH_AV) == 0) {
1197 		if (--t <= 0) {
1198 			pmz_error("irda_setup timed out on get_version byte\n");
1199 			goto out;
1200 		}
1201 		udelay(10);
1202 	}
1203 	version = read_zsdata(uap);
1204 
1205 	if (version < 4) {
1206 		pmz_info("IrDA: dongle version %d not supported\n", version);
1207 		goto out;
1208 	}
1209 
1210 	/* Send speed mode */
1211 	write_zsdata(uap, cmdbyte);
1212 	t = 5000;
1213 	while ((read_zsreg(uap, R0) & Rx_CH_AV) == 0) {
1214 		if (--t <= 0) {
1215 			pmz_error("irda_setup timed out on speed mode byte\n");
1216 			goto out;
1217 		}
1218 		udelay(10);
1219 	}
1220 	t = read_zsdata(uap);
1221 	if (t != cmdbyte)
1222 		pmz_error("irda_setup speed mode byte = %x (%x)\n", t, cmdbyte);
1223 
1224 	pmz_info("IrDA setup for %ld bps, dongle version: %d\n",
1225 		 *baud, version);
1226 
1227 	(void)read_zsdata(uap);
1228 	(void)read_zsdata(uap);
1229 	(void)read_zsdata(uap);
1230 
1231  out:
1232 	/* Switch back to data mode */
1233 	uap->curregs[R5] &= ~DTR;
1234 	write_zsreg(uap, R5, uap->curregs[R5]);
1235 	zssync(uap);
1236 
1237 	(void)read_zsdata(uap);
1238 	(void)read_zsdata(uap);
1239 	(void)read_zsdata(uap);
1240 }
1241 
1242 
1243 static void __pmz_set_termios(struct uart_port *port, struct ktermios *termios,
1244 			      struct ktermios *old)
1245 {
1246 	struct uart_pmac_port *uap = to_pmz(port);
1247 	unsigned long baud;
1248 
1249 	pmz_debug("pmz: set_termios()\n");
1250 
1251 	memcpy(&uap->termios_cache, termios, sizeof(struct ktermios));
1252 
1253 	/* XXX Check which revs of machines actually allow 1 and 4Mb speeds
1254 	 * on the IR dongle. Note that the IRTTY driver currently doesn't know
1255 	 * about the FIR mode and high speed modes. So these are unused. For
1256 	 * implementing proper support for these, we should probably add some
1257 	 * DMA as well, at least on the Rx side, which isn't a simple thing
1258 	 * at this point.
1259 	 */
1260 	if (ZS_IS_IRDA(uap)) {
1261 		/* Calc baud rate */
1262 		baud = uart_get_baud_rate(port, termios, old, 1200, 4000000);
1263 		pmz_debug("pmz: switch IRDA to %ld bauds\n", baud);
1264 		/* Cet the irda codec to the right rate */
1265 		pmz_irda_setup(uap, &baud);
1266 		/* Set final baud rate */
1267 		pmz_convert_to_zs(uap, termios->c_cflag, termios->c_iflag, baud);
1268 		pmz_load_zsregs(uap, uap->curregs);
1269 		zssync(uap);
1270 	} else {
1271 		baud = uart_get_baud_rate(port, termios, old, 1200, 230400);
1272 		pmz_convert_to_zs(uap, termios->c_cflag, termios->c_iflag, baud);
1273 		/* Make sure modem status interrupts are correctly configured */
1274 		if (UART_ENABLE_MS(&uap->port, termios->c_cflag)) {
1275 			uap->curregs[R15] |= DCDIE | SYNCIE | CTSIE;
1276 			uap->flags |= PMACZILOG_FLAG_MODEM_STATUS;
1277 		} else {
1278 			uap->curregs[R15] &= ~(DCDIE | SYNCIE | CTSIE);
1279 			uap->flags &= ~PMACZILOG_FLAG_MODEM_STATUS;
1280 		}
1281 
1282 		/* Load registers to the chip */
1283 		pmz_maybe_update_regs(uap);
1284 	}
1285 	uart_update_timeout(port, termios->c_cflag, baud);
1286 
1287 	pmz_debug("pmz: set_termios() done.\n");
1288 }
1289 
1290 /* The port lock is not held.  */
1291 static void pmz_set_termios(struct uart_port *port, struct ktermios *termios,
1292 			    struct ktermios *old)
1293 {
1294 	struct uart_pmac_port *uap = to_pmz(port);
1295 	unsigned long flags;
1296 
1297 	spin_lock_irqsave(&port->lock, flags);
1298 
1299 	/* Disable IRQs on the port */
1300 	pmz_interrupt_control(uap, 0);
1301 
1302 	/* Setup new port configuration */
1303 	__pmz_set_termios(port, termios, old);
1304 
1305 	/* Re-enable IRQs on the port */
1306 	if (ZS_IS_OPEN(uap))
1307 		pmz_interrupt_control(uap, 1);
1308 
1309 	spin_unlock_irqrestore(&port->lock, flags);
1310 }
1311 
1312 static const char *pmz_type(struct uart_port *port)
1313 {
1314 	struct uart_pmac_port *uap = to_pmz(port);
1315 
1316 	if (ZS_IS_IRDA(uap))
1317 		return "Z85c30 ESCC - Infrared port";
1318 	else if (ZS_IS_INTMODEM(uap))
1319 		return "Z85c30 ESCC - Internal modem";
1320 	return "Z85c30 ESCC - Serial port";
1321 }
1322 
1323 /* We do not request/release mappings of the registers here, this
1324  * happens at early serial probe time.
1325  */
1326 static void pmz_release_port(struct uart_port *port)
1327 {
1328 }
1329 
1330 static int pmz_request_port(struct uart_port *port)
1331 {
1332 	return 0;
1333 }
1334 
1335 /* These do not need to do anything interesting either.  */
1336 static void pmz_config_port(struct uart_port *port, int flags)
1337 {
1338 }
1339 
1340 /* We do not support letting the user mess with the divisor, IRQ, etc. */
1341 static int pmz_verify_port(struct uart_port *port, struct serial_struct *ser)
1342 {
1343 	return -EINVAL;
1344 }
1345 
1346 #ifdef CONFIG_CONSOLE_POLL
1347 
1348 static int pmz_poll_get_char(struct uart_port *port)
1349 {
1350 	struct uart_pmac_port *uap = (struct uart_pmac_port *)port;
1351 	int tries = 2;
1352 
1353 	while (tries) {
1354 		if ((read_zsreg(uap, R0) & Rx_CH_AV) != 0)
1355 			return read_zsdata(uap);
1356 		if (tries--)
1357 			udelay(5);
1358 	}
1359 
1360 	return NO_POLL_CHAR;
1361 }
1362 
1363 static void pmz_poll_put_char(struct uart_port *port, unsigned char c)
1364 {
1365 	struct uart_pmac_port *uap = (struct uart_pmac_port *)port;
1366 
1367 	/* Wait for the transmit buffer to empty. */
1368 	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0)
1369 		udelay(5);
1370 	write_zsdata(uap, c);
1371 }
1372 
1373 #endif /* CONFIG_CONSOLE_POLL */
1374 
1375 static struct uart_ops pmz_pops = {
1376 	.tx_empty	=	pmz_tx_empty,
1377 	.set_mctrl	=	pmz_set_mctrl,
1378 	.get_mctrl	=	pmz_get_mctrl,
1379 	.stop_tx	=	pmz_stop_tx,
1380 	.start_tx	=	pmz_start_tx,
1381 	.stop_rx	=	pmz_stop_rx,
1382 	.enable_ms	=	pmz_enable_ms,
1383 	.break_ctl	=	pmz_break_ctl,
1384 	.startup	=	pmz_startup,
1385 	.shutdown	=	pmz_shutdown,
1386 	.set_termios	=	pmz_set_termios,
1387 	.type		=	pmz_type,
1388 	.release_port	=	pmz_release_port,
1389 	.request_port	=	pmz_request_port,
1390 	.config_port	=	pmz_config_port,
1391 	.verify_port	=	pmz_verify_port,
1392 #ifdef CONFIG_CONSOLE_POLL
1393 	.poll_get_char	=	pmz_poll_get_char,
1394 	.poll_put_char	=	pmz_poll_put_char,
1395 #endif
1396 };
1397 
1398 #ifdef CONFIG_PPC_PMAC
1399 
1400 /*
1401  * Setup one port structure after probing, HW is down at this point,
1402  * Unlike sunzilog, we don't need to pre-init the spinlock as we don't
1403  * register our console before uart_add_one_port() is called
1404  */
1405 static int __init pmz_init_port(struct uart_pmac_port *uap)
1406 {
1407 	struct device_node *np = uap->node;
1408 	const char *conn;
1409 	const struct slot_names_prop {
1410 		int	count;
1411 		char	name[1];
1412 	} *slots;
1413 	int len;
1414 	struct resource r_ports, r_rxdma, r_txdma;
1415 
1416 	/*
1417 	 * Request & map chip registers
1418 	 */
1419 	if (of_address_to_resource(np, 0, &r_ports))
1420 		return -ENODEV;
1421 	uap->port.mapbase = r_ports.start;
1422 	uap->port.membase = ioremap(uap->port.mapbase, 0x1000);
1423 
1424 	uap->control_reg = uap->port.membase;
1425 	uap->data_reg = uap->control_reg + 0x10;
1426 
1427 	/*
1428 	 * Request & map DBDMA registers
1429 	 */
1430 #ifdef HAS_DBDMA
1431 	if (of_address_to_resource(np, 1, &r_txdma) == 0 &&
1432 	    of_address_to_resource(np, 2, &r_rxdma) == 0)
1433 		uap->flags |= PMACZILOG_FLAG_HAS_DMA;
1434 #else
1435 	memset(&r_txdma, 0, sizeof(struct resource));
1436 	memset(&r_rxdma, 0, sizeof(struct resource));
1437 #endif
1438 	if (ZS_HAS_DMA(uap)) {
1439 		uap->tx_dma_regs = ioremap(r_txdma.start, 0x100);
1440 		if (uap->tx_dma_regs == NULL) {
1441 			uap->flags &= ~PMACZILOG_FLAG_HAS_DMA;
1442 			goto no_dma;
1443 		}
1444 		uap->rx_dma_regs = ioremap(r_rxdma.start, 0x100);
1445 		if (uap->rx_dma_regs == NULL) {
1446 			iounmap(uap->tx_dma_regs);
1447 			uap->tx_dma_regs = NULL;
1448 			uap->flags &= ~PMACZILOG_FLAG_HAS_DMA;
1449 			goto no_dma;
1450 		}
1451 		uap->tx_dma_irq = irq_of_parse_and_map(np, 1);
1452 		uap->rx_dma_irq = irq_of_parse_and_map(np, 2);
1453 	}
1454 no_dma:
1455 
1456 	/*
1457 	 * Detect port type
1458 	 */
1459 	if (of_device_is_compatible(np, "cobalt"))
1460 		uap->flags |= PMACZILOG_FLAG_IS_INTMODEM;
1461 	conn = of_get_property(np, "AAPL,connector", &len);
1462 	if (conn && (strcmp(conn, "infrared") == 0))
1463 		uap->flags |= PMACZILOG_FLAG_IS_IRDA;
1464 	uap->port_type = PMAC_SCC_ASYNC;
1465 	/* 1999 Powerbook G3 has slot-names property instead */
1466 	slots = of_get_property(np, "slot-names", &len);
1467 	if (slots && slots->count > 0) {
1468 		if (strcmp(slots->name, "IrDA") == 0)
1469 			uap->flags |= PMACZILOG_FLAG_IS_IRDA;
1470 		else if (strcmp(slots->name, "Modem") == 0)
1471 			uap->flags |= PMACZILOG_FLAG_IS_INTMODEM;
1472 	}
1473 	if (ZS_IS_IRDA(uap))
1474 		uap->port_type = PMAC_SCC_IRDA;
1475 	if (ZS_IS_INTMODEM(uap)) {
1476 		struct device_node* i2c_modem =
1477 			of_find_node_by_name(NULL, "i2c-modem");
1478 		if (i2c_modem) {
1479 			const char* mid =
1480 				of_get_property(i2c_modem, "modem-id", NULL);
1481 			if (mid) switch(*mid) {
1482 			case 0x04 :
1483 			case 0x05 :
1484 			case 0x07 :
1485 			case 0x08 :
1486 			case 0x0b :
1487 			case 0x0c :
1488 				uap->port_type = PMAC_SCC_I2S1;
1489 			}
1490 			printk(KERN_INFO "pmac_zilog: i2c-modem detected, id: %d\n",
1491 				mid ? (*mid) : 0);
1492 			of_node_put(i2c_modem);
1493 		} else {
1494 			printk(KERN_INFO "pmac_zilog: serial modem detected\n");
1495 		}
1496 	}
1497 
1498 	/*
1499 	 * Init remaining bits of "port" structure
1500 	 */
1501 	uap->port.iotype = UPIO_MEM;
1502 	uap->port.irq = irq_of_parse_and_map(np, 0);
1503 	uap->port.uartclk = ZS_CLOCK;
1504 	uap->port.fifosize = 1;
1505 	uap->port.ops = &pmz_pops;
1506 	uap->port.type = PORT_PMAC_ZILOG;
1507 	uap->port.flags = 0;
1508 
1509 	/*
1510 	 * Fixup for the port on Gatwick for which the device-tree has
1511 	 * missing interrupts. Normally, the macio_dev would contain
1512 	 * fixed up interrupt info, but we use the device-tree directly
1513 	 * here due to early probing so we need the fixup too.
1514 	 */
1515 	if (uap->port.irq == 0 &&
1516 	    np->parent && np->parent->parent &&
1517 	    of_device_is_compatible(np->parent->parent, "gatwick")) {
1518 		/* IRQs on gatwick are offset by 64 */
1519 		uap->port.irq = irq_create_mapping(NULL, 64 + 15);
1520 		uap->tx_dma_irq = irq_create_mapping(NULL, 64 + 4);
1521 		uap->rx_dma_irq = irq_create_mapping(NULL, 64 + 5);
1522 	}
1523 
1524 	/* Setup some valid baud rate information in the register
1525 	 * shadows so we don't write crap there before baud rate is
1526 	 * first initialized.
1527 	 */
1528 	pmz_convert_to_zs(uap, CS8, 0, 9600);
1529 
1530 	return 0;
1531 }
1532 
1533 /*
1534  * Get rid of a port on module removal
1535  */
1536 static void pmz_dispose_port(struct uart_pmac_port *uap)
1537 {
1538 	struct device_node *np;
1539 
1540 	np = uap->node;
1541 	iounmap(uap->rx_dma_regs);
1542 	iounmap(uap->tx_dma_regs);
1543 	iounmap(uap->control_reg);
1544 	uap->node = NULL;
1545 	of_node_put(np);
1546 	memset(uap, 0, sizeof(struct uart_pmac_port));
1547 }
1548 
1549 /*
1550  * Called upon match with an escc node in the device-tree.
1551  */
1552 static int pmz_attach(struct macio_dev *mdev, const struct of_device_id *match)
1553 {
1554 	struct uart_pmac_port *uap;
1555 	int i;
1556 
1557 	/* Iterate the pmz_ports array to find a matching entry
1558 	 */
1559 	for (i = 0; i < MAX_ZS_PORTS; i++)
1560 		if (pmz_ports[i].node == mdev->ofdev.dev.of_node)
1561 			break;
1562 	if (i >= MAX_ZS_PORTS)
1563 		return -ENODEV;
1564 
1565 
1566 	uap = &pmz_ports[i];
1567 	uap->dev = mdev;
1568 	uap->port.dev = &mdev->ofdev.dev;
1569 	dev_set_drvdata(&mdev->ofdev.dev, uap);
1570 
1571 	/* We still activate the port even when failing to request resources
1572 	 * to work around bugs in ancient Apple device-trees
1573 	 */
1574 	if (macio_request_resources(uap->dev, "pmac_zilog"))
1575 		printk(KERN_WARNING "%s: Failed to request resource"
1576 		       ", port still active\n",
1577 		       uap->node->name);
1578 	else
1579 		uap->flags |= PMACZILOG_FLAG_RSRC_REQUESTED;
1580 
1581 	return uart_add_one_port(&pmz_uart_reg, &uap->port);
1582 }
1583 
1584 /*
1585  * That one should not be called, macio isn't really a hotswap device,
1586  * we don't expect one of those serial ports to go away...
1587  */
1588 static int pmz_detach(struct macio_dev *mdev)
1589 {
1590 	struct uart_pmac_port	*uap = dev_get_drvdata(&mdev->ofdev.dev);
1591 
1592 	if (!uap)
1593 		return -ENODEV;
1594 
1595 	uart_remove_one_port(&pmz_uart_reg, &uap->port);
1596 
1597 	if (uap->flags & PMACZILOG_FLAG_RSRC_REQUESTED) {
1598 		macio_release_resources(uap->dev);
1599 		uap->flags &= ~PMACZILOG_FLAG_RSRC_REQUESTED;
1600 	}
1601 	dev_set_drvdata(&mdev->ofdev.dev, NULL);
1602 	uap->dev = NULL;
1603 	uap->port.dev = NULL;
1604 
1605 	return 0;
1606 }
1607 
1608 
1609 static int pmz_suspend(struct macio_dev *mdev, pm_message_t pm_state)
1610 {
1611 	struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev);
1612 
1613 	if (uap == NULL) {
1614 		printk("HRM... pmz_suspend with NULL uap\n");
1615 		return 0;
1616 	}
1617 
1618 	uart_suspend_port(&pmz_uart_reg, &uap->port);
1619 
1620 	return 0;
1621 }
1622 
1623 
1624 static int pmz_resume(struct macio_dev *mdev)
1625 {
1626 	struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev);
1627 
1628 	if (uap == NULL)
1629 		return 0;
1630 
1631 	uart_resume_port(&pmz_uart_reg, &uap->port);
1632 
1633 	return 0;
1634 }
1635 
1636 /*
1637  * Probe all ports in the system and build the ports array, we register
1638  * with the serial layer later, so we get a proper struct device which
1639  * allows the tty to attach properly. This is later than it used to be
1640  * but the tty layer really wants it that way.
1641  */
1642 static int __init pmz_probe(void)
1643 {
1644 	struct device_node	*node_p, *node_a, *node_b, *np;
1645 	int			count = 0;
1646 	int			rc;
1647 
1648 	/*
1649 	 * Find all escc chips in the system
1650 	 */
1651 	node_p = of_find_node_by_name(NULL, "escc");
1652 	while (node_p) {
1653 		/*
1654 		 * First get channel A/B node pointers
1655 		 *
1656 		 * TODO: Add routines with proper locking to do that...
1657 		 */
1658 		node_a = node_b = NULL;
1659 		for (np = NULL; (np = of_get_next_child(node_p, np)) != NULL;) {
1660 			if (strncmp(np->name, "ch-a", 4) == 0)
1661 				node_a = of_node_get(np);
1662 			else if (strncmp(np->name, "ch-b", 4) == 0)
1663 				node_b = of_node_get(np);
1664 		}
1665 		if (!node_a && !node_b) {
1666 			of_node_put(node_a);
1667 			of_node_put(node_b);
1668 			printk(KERN_ERR "pmac_zilog: missing node %c for escc %s\n",
1669 				(!node_a) ? 'a' : 'b', node_p->full_name);
1670 			goto next;
1671 		}
1672 
1673 		/*
1674 		 * Fill basic fields in the port structures
1675 		 */
1676 		if (node_b != NULL) {
1677 			pmz_ports[count].mate		= &pmz_ports[count+1];
1678 			pmz_ports[count+1].mate		= &pmz_ports[count];
1679 		}
1680 		pmz_ports[count].flags		= PMACZILOG_FLAG_IS_CHANNEL_A;
1681 		pmz_ports[count].node		= node_a;
1682 		pmz_ports[count+1].node		= node_b;
1683 		pmz_ports[count].port.line	= count;
1684 		pmz_ports[count+1].port.line	= count+1;
1685 
1686 		/*
1687 		 * Setup the ports for real
1688 		 */
1689 		rc = pmz_init_port(&pmz_ports[count]);
1690 		if (rc == 0 && node_b != NULL)
1691 			rc = pmz_init_port(&pmz_ports[count+1]);
1692 		if (rc != 0) {
1693 			of_node_put(node_a);
1694 			of_node_put(node_b);
1695 			memset(&pmz_ports[count], 0, sizeof(struct uart_pmac_port));
1696 			memset(&pmz_ports[count+1], 0, sizeof(struct uart_pmac_port));
1697 			goto next;
1698 		}
1699 		count += 2;
1700 next:
1701 		node_p = of_find_node_by_name(node_p, "escc");
1702 	}
1703 	pmz_ports_count = count;
1704 
1705 	return 0;
1706 }
1707 
1708 #else
1709 
1710 extern struct platform_device scc_a_pdev, scc_b_pdev;
1711 
1712 static int __init pmz_init_port(struct uart_pmac_port *uap)
1713 {
1714 	struct resource *r_ports;
1715 	int irq;
1716 
1717 	r_ports = platform_get_resource(uap->pdev, IORESOURCE_MEM, 0);
1718 	irq = platform_get_irq(uap->pdev, 0);
1719 	if (!r_ports || !irq)
1720 		return -ENODEV;
1721 
1722 	uap->port.mapbase  = r_ports->start;
1723 	uap->port.membase  = (unsigned char __iomem *) r_ports->start;
1724 	uap->port.iotype   = UPIO_MEM;
1725 	uap->port.irq      = irq;
1726 	uap->port.uartclk  = ZS_CLOCK;
1727 	uap->port.fifosize = 1;
1728 	uap->port.ops      = &pmz_pops;
1729 	uap->port.type     = PORT_PMAC_ZILOG;
1730 	uap->port.flags    = 0;
1731 
1732 	uap->control_reg   = uap->port.membase;
1733 	uap->data_reg      = uap->control_reg + 4;
1734 	uap->port_type     = 0;
1735 
1736 	pmz_convert_to_zs(uap, CS8, 0, 9600);
1737 
1738 	return 0;
1739 }
1740 
1741 static int __init pmz_probe(void)
1742 {
1743 	int err;
1744 
1745 	pmz_ports_count = 0;
1746 
1747 	pmz_ports[0].port.line = 0;
1748 	pmz_ports[0].flags     = PMACZILOG_FLAG_IS_CHANNEL_A;
1749 	pmz_ports[0].pdev      = &scc_a_pdev;
1750 	err = pmz_init_port(&pmz_ports[0]);
1751 	if (err)
1752 		return err;
1753 	pmz_ports_count++;
1754 
1755 	pmz_ports[0].mate      = &pmz_ports[1];
1756 	pmz_ports[1].mate      = &pmz_ports[0];
1757 	pmz_ports[1].port.line = 1;
1758 	pmz_ports[1].flags     = 0;
1759 	pmz_ports[1].pdev      = &scc_b_pdev;
1760 	err = pmz_init_port(&pmz_ports[1]);
1761 	if (err)
1762 		return err;
1763 	pmz_ports_count++;
1764 
1765 	return 0;
1766 }
1767 
1768 static void pmz_dispose_port(struct uart_pmac_port *uap)
1769 {
1770 	memset(uap, 0, sizeof(struct uart_pmac_port));
1771 }
1772 
1773 static int __init pmz_attach(struct platform_device *pdev)
1774 {
1775 	struct uart_pmac_port *uap;
1776 	int i;
1777 
1778 	/* Iterate the pmz_ports array to find a matching entry */
1779 	for (i = 0; i < pmz_ports_count; i++)
1780 		if (pmz_ports[i].pdev == pdev)
1781 			break;
1782 	if (i >= pmz_ports_count)
1783 		return -ENODEV;
1784 
1785 	uap = &pmz_ports[i];
1786 	uap->port.dev = &pdev->dev;
1787 	platform_set_drvdata(pdev, uap);
1788 
1789 	return uart_add_one_port(&pmz_uart_reg, &uap->port);
1790 }
1791 
1792 static int __exit pmz_detach(struct platform_device *pdev)
1793 {
1794 	struct uart_pmac_port *uap = platform_get_drvdata(pdev);
1795 
1796 	if (!uap)
1797 		return -ENODEV;
1798 
1799 	uart_remove_one_port(&pmz_uart_reg, &uap->port);
1800 
1801 	platform_set_drvdata(pdev, NULL);
1802 	uap->port.dev = NULL;
1803 
1804 	return 0;
1805 }
1806 
1807 #endif /* !CONFIG_PPC_PMAC */
1808 
1809 #ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
1810 
1811 static void pmz_console_write(struct console *con, const char *s, unsigned int count);
1812 static int __init pmz_console_setup(struct console *co, char *options);
1813 
1814 static struct console pmz_console = {
1815 	.name	=	PMACZILOG_NAME,
1816 	.write	=	pmz_console_write,
1817 	.device	=	uart_console_device,
1818 	.setup	=	pmz_console_setup,
1819 	.flags	=	CON_PRINTBUFFER,
1820 	.index	=	-1,
1821 	.data   =	&pmz_uart_reg,
1822 };
1823 
1824 #define PMACZILOG_CONSOLE	&pmz_console
1825 #else /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
1826 #define PMACZILOG_CONSOLE	(NULL)
1827 #endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
1828 
1829 /*
1830  * Register the driver, console driver and ports with the serial
1831  * core
1832  */
1833 static int __init pmz_register(void)
1834 {
1835 	pmz_uart_reg.nr = pmz_ports_count;
1836 	pmz_uart_reg.cons = PMACZILOG_CONSOLE;
1837 
1838 	/*
1839 	 * Register this driver with the serial core
1840 	 */
1841 	return uart_register_driver(&pmz_uart_reg);
1842 }
1843 
1844 #ifdef CONFIG_PPC_PMAC
1845 
1846 static struct of_device_id pmz_match[] =
1847 {
1848 	{
1849 	.name		= "ch-a",
1850 	},
1851 	{
1852 	.name		= "ch-b",
1853 	},
1854 	{},
1855 };
1856 MODULE_DEVICE_TABLE (of, pmz_match);
1857 
1858 static struct macio_driver pmz_driver = {
1859 	.driver = {
1860 		.name 		= "pmac_zilog",
1861 		.owner		= THIS_MODULE,
1862 		.of_match_table	= pmz_match,
1863 	},
1864 	.probe		= pmz_attach,
1865 	.remove		= pmz_detach,
1866 	.suspend	= pmz_suspend,
1867 	.resume		= pmz_resume,
1868 };
1869 
1870 #else
1871 
1872 static struct platform_driver pmz_driver = {
1873 	.remove		= __exit_p(pmz_detach),
1874 	.driver		= {
1875 		.name		= "scc",
1876 		.owner		= THIS_MODULE,
1877 	},
1878 };
1879 
1880 #endif /* !CONFIG_PPC_PMAC */
1881 
1882 static int __init init_pmz(void)
1883 {
1884 	int rc, i;
1885 	printk(KERN_INFO "%s\n", version);
1886 
1887 	/*
1888 	 * First, we need to do a direct OF-based probe pass. We
1889 	 * do that because we want serial console up before the
1890 	 * macio stuffs calls us back, and since that makes it
1891 	 * easier to pass the proper number of channels to
1892 	 * uart_register_driver()
1893 	 */
1894 	if (pmz_ports_count == 0)
1895 		pmz_probe();
1896 
1897 	/*
1898 	 * Bail early if no port found
1899 	 */
1900 	if (pmz_ports_count == 0)
1901 		return -ENODEV;
1902 
1903 	/*
1904 	 * Now we register with the serial layer
1905 	 */
1906 	rc = pmz_register();
1907 	if (rc) {
1908 		printk(KERN_ERR
1909 			"pmac_zilog: Error registering serial device, disabling pmac_zilog.\n"
1910 		 	"pmac_zilog: Did another serial driver already claim the minors?\n");
1911 		/* effectively "pmz_unprobe()" */
1912 		for (i=0; i < pmz_ports_count; i++)
1913 			pmz_dispose_port(&pmz_ports[i]);
1914 		return rc;
1915 	}
1916 
1917 	/*
1918 	 * Then we register the macio driver itself
1919 	 */
1920 #ifdef CONFIG_PPC_PMAC
1921 	return macio_register_driver(&pmz_driver);
1922 #else
1923 	return platform_driver_probe(&pmz_driver, pmz_attach);
1924 #endif
1925 }
1926 
1927 static void __exit exit_pmz(void)
1928 {
1929 	int i;
1930 
1931 #ifdef CONFIG_PPC_PMAC
1932 	/* Get rid of macio-driver (detach from macio) */
1933 	macio_unregister_driver(&pmz_driver);
1934 #else
1935 	platform_driver_unregister(&pmz_driver);
1936 #endif
1937 
1938 	for (i = 0; i < pmz_ports_count; i++) {
1939 		struct uart_pmac_port *uport = &pmz_ports[i];
1940 #ifdef CONFIG_PPC_PMAC
1941 		if (uport->node != NULL)
1942 			pmz_dispose_port(uport);
1943 #else
1944 		if (uport->pdev != NULL)
1945 			pmz_dispose_port(uport);
1946 #endif
1947 	}
1948 	/* Unregister UART driver */
1949 	uart_unregister_driver(&pmz_uart_reg);
1950 }
1951 
1952 #ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
1953 
1954 static void pmz_console_putchar(struct uart_port *port, int ch)
1955 {
1956 	struct uart_pmac_port *uap = (struct uart_pmac_port *)port;
1957 
1958 	/* Wait for the transmit buffer to empty. */
1959 	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0)
1960 		udelay(5);
1961 	write_zsdata(uap, ch);
1962 }
1963 
1964 /*
1965  * Print a string to the serial port trying not to disturb
1966  * any possible real use of the port...
1967  */
1968 static void pmz_console_write(struct console *con, const char *s, unsigned int count)
1969 {
1970 	struct uart_pmac_port *uap = &pmz_ports[con->index];
1971 	unsigned long flags;
1972 
1973 	spin_lock_irqsave(&uap->port.lock, flags);
1974 
1975 	/* Turn of interrupts and enable the transmitter. */
1976 	write_zsreg(uap, R1, uap->curregs[1] & ~TxINT_ENAB);
1977 	write_zsreg(uap, R5, uap->curregs[5] | TxENABLE | RTS | DTR);
1978 
1979 	uart_console_write(&uap->port, s, count, pmz_console_putchar);
1980 
1981 	/* Restore the values in the registers. */
1982 	write_zsreg(uap, R1, uap->curregs[1]);
1983 	/* Don't disable the transmitter. */
1984 
1985 	spin_unlock_irqrestore(&uap->port.lock, flags);
1986 }
1987 
1988 /*
1989  * Setup the serial console
1990  */
1991 static int __init pmz_console_setup(struct console *co, char *options)
1992 {
1993 	struct uart_pmac_port *uap;
1994 	struct uart_port *port;
1995 	int baud = 38400;
1996 	int bits = 8;
1997 	int parity = 'n';
1998 	int flow = 'n';
1999 	unsigned long pwr_delay;
2000 
2001 	/*
2002 	 * XServe's default to 57600 bps
2003 	 */
2004 	if (of_machine_is_compatible("RackMac1,1")
2005 	    || of_machine_is_compatible("RackMac1,2")
2006 	    || of_machine_is_compatible("MacRISC4"))
2007 		baud = 57600;
2008 
2009 	/*
2010 	 * Check whether an invalid uart number has been specified, and
2011 	 * if so, search for the first available port that does have
2012 	 * console support.
2013 	 */
2014 	if (co->index >= pmz_ports_count)
2015 		co->index = 0;
2016 	uap = &pmz_ports[co->index];
2017 #ifdef CONFIG_PPC_PMAC
2018 	if (uap->node == NULL)
2019 		return -ENODEV;
2020 #else
2021 	if (uap->pdev == NULL)
2022 		return -ENODEV;
2023 #endif
2024 	port = &uap->port;
2025 
2026 	/*
2027 	 * Mark port as beeing a console
2028 	 */
2029 	uap->flags |= PMACZILOG_FLAG_IS_CONS;
2030 
2031 	/*
2032 	 * Temporary fix for uart layer who didn't setup the spinlock yet
2033 	 */
2034 	spin_lock_init(&port->lock);
2035 
2036 	/*
2037 	 * Enable the hardware
2038 	 */
2039 	pwr_delay = __pmz_startup(uap);
2040 	if (pwr_delay)
2041 		mdelay(pwr_delay);
2042 
2043 	if (options)
2044 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2045 
2046 	return uart_set_options(port, co, baud, parity, bits, flow);
2047 }
2048 
2049 static int __init pmz_console_init(void)
2050 {
2051 	/* Probe ports */
2052 	pmz_probe();
2053 
2054 	/* TODO: Autoprobe console based on OF */
2055 	/* pmz_console.index = i; */
2056 	register_console(&pmz_console);
2057 
2058 	return 0;
2059 
2060 }
2061 console_initcall(pmz_console_init);
2062 #endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
2063 
2064 module_init(init_pmz);
2065 module_exit(exit_pmz);
2066