xref: /openbmc/linux/drivers/tty/serial/pmac_zilog.c (revision 565d76cb)
1 /*
2  * linux/drivers/serial/pmac_zilog.c
3  *
4  * Driver for PowerMac Z85c30 based ESCC cell found in the
5  * "macio" ASICs of various PowerMac models
6  *
7  * Copyright (C) 2003 Ben. Herrenschmidt (benh@kernel.crashing.org)
8  *
9  * Derived from drivers/macintosh/macserial.c by Paul Mackerras
10  * and drivers/serial/sunzilog.c by David S. Miller
11  *
12  * Hrm... actually, I ripped most of sunzilog (Thanks David !) and
13  * adapted special tweaks needed for us. I don't think it's worth
14  * merging back those though. The DMA code still has to get in
15  * and once done, I expect that driver to remain fairly stable in
16  * the long term, unless we change the driver model again...
17  *
18  * This program is free software; you can redistribute it and/or modify
19  * it under the terms of the GNU General Public License as published by
20  * the Free Software Foundation; either version 2 of the License, or
21  * (at your option) any later version.
22  *
23  * This program is distributed in the hope that it will be useful,
24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
26  * GNU General Public License for more details.
27  *
28  * You should have received a copy of the GNU General Public License
29  * along with this program; if not, write to the Free Software
30  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
31  *
32  * 2004-08-06 Harald Welte <laforge@gnumonks.org>
33  *	- Enable BREAK interrupt
34  *	- Add support for sysreq
35  *
36  * TODO:   - Add DMA support
37  *         - Defer port shutdown to a few seconds after close
38  *         - maybe put something right into uap->clk_divisor
39  */
40 
41 #undef DEBUG
42 #undef DEBUG_HARD
43 #undef USE_CTRL_O_SYSRQ
44 
45 #include <linux/module.h>
46 #include <linux/tty.h>
47 
48 #include <linux/tty_flip.h>
49 #include <linux/major.h>
50 #include <linux/string.h>
51 #include <linux/fcntl.h>
52 #include <linux/mm.h>
53 #include <linux/kernel.h>
54 #include <linux/delay.h>
55 #include <linux/init.h>
56 #include <linux/console.h>
57 #include <linux/adb.h>
58 #include <linux/pmu.h>
59 #include <linux/bitops.h>
60 #include <linux/sysrq.h>
61 #include <linux/mutex.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 
105 /*
106  * For the sake of early serial console, we can do a pre-probe
107  * (optional) of the ports at rather early boot time.
108  */
109 static struct uart_pmac_port	pmz_ports[MAX_ZS_PORTS];
110 static int			pmz_ports_count;
111 static DEFINE_MUTEX(pmz_irq_mutex);
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 	if (ZS_IS_ASLEEP(uap))
132 		return;
133 
134 	/* Let pending transmits finish.  */
135 	for (i = 0; i < 1000; i++) {
136 		unsigned char stat = read_zsreg(uap, R1);
137 		if (stat & ALL_SNT)
138 			break;
139 		udelay(100);
140 	}
141 
142 	ZS_CLEARERR(uap);
143 	zssync(uap);
144 	ZS_CLEARFIFO(uap);
145 	zssync(uap);
146 	ZS_CLEARERR(uap);
147 
148 	/* Disable all interrupts.  */
149 	write_zsreg(uap, R1,
150 		    regs[R1] & ~(RxINT_MASK | TxINT_ENAB | EXT_INT_ENAB));
151 
152 	/* Set parity, sync config, stop bits, and clock divisor.  */
153 	write_zsreg(uap, R4, regs[R4]);
154 
155 	/* Set misc. TX/RX control bits.  */
156 	write_zsreg(uap, R10, regs[R10]);
157 
158 	/* Set TX/RX controls sans the enable bits.  */
159 	write_zsreg(uap, R3, regs[R3] & ~RxENABLE);
160 	write_zsreg(uap, R5, regs[R5] & ~TxENABLE);
161 
162 	/* now set R7 "prime" on ESCC */
163 	write_zsreg(uap, R15, regs[R15] | EN85C30);
164 	write_zsreg(uap, R7, regs[R7P]);
165 
166 	/* make sure we use R7 "non-prime" on ESCC */
167 	write_zsreg(uap, R15, regs[R15] & ~EN85C30);
168 
169 	/* Synchronous mode config.  */
170 	write_zsreg(uap, R6, regs[R6]);
171 	write_zsreg(uap, R7, regs[R7]);
172 
173 	/* Disable baud generator.  */
174 	write_zsreg(uap, R14, regs[R14] & ~BRENAB);
175 
176 	/* Clock mode control.  */
177 	write_zsreg(uap, R11, regs[R11]);
178 
179 	/* Lower and upper byte of baud rate generator divisor.  */
180 	write_zsreg(uap, R12, regs[R12]);
181 	write_zsreg(uap, R13, regs[R13]);
182 
183 	/* Now rewrite R14, with BRENAB (if set).  */
184 	write_zsreg(uap, R14, regs[R14]);
185 
186 	/* Reset external status interrupts.  */
187 	write_zsreg(uap, R0, RES_EXT_INT);
188 	write_zsreg(uap, R0, RES_EXT_INT);
189 
190 	/* Rewrite R3/R5, this time without enables masked.  */
191 	write_zsreg(uap, R3, regs[R3]);
192 	write_zsreg(uap, R5, regs[R5]);
193 
194 	/* Rewrite R1, this time without IRQ enabled masked.  */
195 	write_zsreg(uap, R1, regs[R1]);
196 
197 	/* Enable interrupts */
198 	write_zsreg(uap, R9, regs[R9]);
199 }
200 
201 /*
202  * We do like sunzilog to avoid disrupting pending Tx
203  * Reprogram the Zilog channel HW registers with the copies found in the
204  * software state struct.  If the transmitter is busy, we defer this update
205  * until the next TX complete interrupt.  Else, we do it right now.
206  *
207  * The UART port lock must be held and local interrupts disabled.
208  */
209 static void pmz_maybe_update_regs(struct uart_pmac_port *uap)
210 {
211 	if (!ZS_REGS_HELD(uap)) {
212 		if (ZS_TX_ACTIVE(uap)) {
213 			uap->flags |= PMACZILOG_FLAG_REGS_HELD;
214 		} else {
215 			pmz_debug("pmz: maybe_update_regs: updating\n");
216 			pmz_load_zsregs(uap, uap->curregs);
217 		}
218 	}
219 }
220 
221 static struct tty_struct *pmz_receive_chars(struct uart_pmac_port *uap)
222 {
223 	struct tty_struct *tty = NULL;
224 	unsigned char ch, r1, drop, error, flag;
225 	int loops = 0;
226 
227 	/* The interrupt can be enabled when the port isn't open, typically
228 	 * that happens when using one port is open and the other closed (stale
229 	 * interrupt) or when one port is used as a console.
230 	 */
231 	if (!ZS_IS_OPEN(uap)) {
232 		pmz_debug("pmz: draining input\n");
233 		/* Port is closed, drain input data */
234 		for (;;) {
235 			if ((++loops) > 1000)
236 				goto flood;
237 			(void)read_zsreg(uap, R1);
238 			write_zsreg(uap, R0, ERR_RES);
239 			(void)read_zsdata(uap);
240 			ch = read_zsreg(uap, R0);
241 			if (!(ch & Rx_CH_AV))
242 				break;
243 		}
244 		return NULL;
245 	}
246 
247 	/* Sanity check, make sure the old bug is no longer happening */
248 	if (uap->port.state == NULL || uap->port.state->port.tty == NULL) {
249 		WARN_ON(1);
250 		(void)read_zsdata(uap);
251 		return NULL;
252 	}
253 	tty = uap->port.state->port.tty;
254 
255 	while (1) {
256 		error = 0;
257 		drop = 0;
258 
259 		r1 = read_zsreg(uap, R1);
260 		ch = read_zsdata(uap);
261 
262 		if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR)) {
263 			write_zsreg(uap, R0, ERR_RES);
264 			zssync(uap);
265 		}
266 
267 		ch &= uap->parity_mask;
268 		if (ch == 0 && uap->flags & PMACZILOG_FLAG_BREAK) {
269 			uap->flags &= ~PMACZILOG_FLAG_BREAK;
270 		}
271 
272 #if defined(CONFIG_MAGIC_SYSRQ) && defined(CONFIG_SERIAL_CORE_CONSOLE)
273 #ifdef USE_CTRL_O_SYSRQ
274 		/* Handle the SysRq ^O Hack */
275 		if (ch == '\x0f') {
276 			uap->port.sysrq = jiffies + HZ*5;
277 			goto next_char;
278 		}
279 #endif /* USE_CTRL_O_SYSRQ */
280 		if (uap->port.sysrq) {
281 			int swallow;
282 			spin_unlock(&uap->port.lock);
283 			swallow = uart_handle_sysrq_char(&uap->port, ch);
284 			spin_lock(&uap->port.lock);
285 			if (swallow)
286 				goto next_char;
287 		}
288 #endif /* CONFIG_MAGIC_SYSRQ && CONFIG_SERIAL_CORE_CONSOLE */
289 
290 		/* A real serial line, record the character and status.  */
291 		if (drop)
292 			goto next_char;
293 
294 		flag = TTY_NORMAL;
295 		uap->port.icount.rx++;
296 
297 		if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR | BRK_ABRT)) {
298 			error = 1;
299 			if (r1 & BRK_ABRT) {
300 				pmz_debug("pmz: got break !\n");
301 				r1 &= ~(PAR_ERR | CRC_ERR);
302 				uap->port.icount.brk++;
303 				if (uart_handle_break(&uap->port))
304 					goto next_char;
305 			}
306 			else if (r1 & PAR_ERR)
307 				uap->port.icount.parity++;
308 			else if (r1 & CRC_ERR)
309 				uap->port.icount.frame++;
310 			if (r1 & Rx_OVR)
311 				uap->port.icount.overrun++;
312 			r1 &= uap->port.read_status_mask;
313 			if (r1 & BRK_ABRT)
314 				flag = TTY_BREAK;
315 			else if (r1 & PAR_ERR)
316 				flag = TTY_PARITY;
317 			else if (r1 & CRC_ERR)
318 				flag = TTY_FRAME;
319 		}
320 
321 		if (uap->port.ignore_status_mask == 0xff ||
322 		    (r1 & uap->port.ignore_status_mask) == 0) {
323 			tty_insert_flip_char(tty, ch, flag);
324 		}
325 		if (r1 & Rx_OVR)
326 			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
327 	next_char:
328 		/* We can get stuck in an infinite loop getting char 0 when the
329 		 * line is in a wrong HW state, we break that here.
330 		 * When that happens, I disable the receive side of the driver.
331 		 * Note that what I've been experiencing is a real irq loop where
332 		 * I'm getting flooded regardless of the actual port speed.
333 		 * Something stange is going on with the HW
334 		 */
335 		if ((++loops) > 1000)
336 			goto flood;
337 		ch = read_zsreg(uap, R0);
338 		if (!(ch & Rx_CH_AV))
339 			break;
340 	}
341 
342 	return tty;
343  flood:
344 	uap->curregs[R1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
345 	write_zsreg(uap, R1, uap->curregs[R1]);
346 	zssync(uap);
347 	pmz_error("pmz: rx irq flood !\n");
348 	return tty;
349 }
350 
351 static void pmz_status_handle(struct uart_pmac_port *uap)
352 {
353 	unsigned char status;
354 
355 	status = read_zsreg(uap, R0);
356 	write_zsreg(uap, R0, RES_EXT_INT);
357 	zssync(uap);
358 
359 	if (ZS_IS_OPEN(uap) && ZS_WANTS_MODEM_STATUS(uap)) {
360 		if (status & SYNC_HUNT)
361 			uap->port.icount.dsr++;
362 
363 		/* The Zilog just gives us an interrupt when DCD/CTS/etc. change.
364 		 * But it does not tell us which bit has changed, we have to keep
365 		 * track of this ourselves.
366 		 * The CTS input is inverted for some reason.  -- paulus
367 		 */
368 		if ((status ^ uap->prev_status) & DCD)
369 			uart_handle_dcd_change(&uap->port,
370 					       (status & DCD));
371 		if ((status ^ uap->prev_status) & CTS)
372 			uart_handle_cts_change(&uap->port,
373 					       !(status & CTS));
374 
375 		wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
376 	}
377 
378 	if (status & BRK_ABRT)
379 		uap->flags |= PMACZILOG_FLAG_BREAK;
380 
381 	uap->prev_status = status;
382 }
383 
384 static void pmz_transmit_chars(struct uart_pmac_port *uap)
385 {
386 	struct circ_buf *xmit;
387 
388 	if (ZS_IS_ASLEEP(uap))
389 		return;
390 	if (ZS_IS_CONS(uap)) {
391 		unsigned char status = read_zsreg(uap, R0);
392 
393 		/* TX still busy?  Just wait for the next TX done interrupt.
394 		 *
395 		 * It can occur because of how we do serial console writes.  It would
396 		 * be nice to transmit console writes just like we normally would for
397 		 * a TTY line. (ie. buffered and TX interrupt driven).  That is not
398 		 * easy because console writes cannot sleep.  One solution might be
399 		 * to poll on enough port->xmit space becomming free.  -DaveM
400 		 */
401 		if (!(status & Tx_BUF_EMP))
402 			return;
403 	}
404 
405 	uap->flags &= ~PMACZILOG_FLAG_TX_ACTIVE;
406 
407 	if (ZS_REGS_HELD(uap)) {
408 		pmz_load_zsregs(uap, uap->curregs);
409 		uap->flags &= ~PMACZILOG_FLAG_REGS_HELD;
410 	}
411 
412 	if (ZS_TX_STOPPED(uap)) {
413 		uap->flags &= ~PMACZILOG_FLAG_TX_STOPPED;
414 		goto ack_tx_int;
415 	}
416 
417 	/* Under some circumstances, we see interrupts reported for
418 	 * a closed channel. The interrupt mask in R1 is clear, but
419 	 * R3 still signals the interrupts and we see them when taking
420 	 * an interrupt for the other channel (this could be a qemu
421 	 * bug but since the ESCC doc doesn't specify precsiely whether
422 	 * R3 interrup status bits are masked by R1 interrupt enable
423 	 * bits, better safe than sorry). --BenH.
424 	 */
425 	if (!ZS_IS_OPEN(uap))
426 		goto ack_tx_int;
427 
428 	if (uap->port.x_char) {
429 		uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
430 		write_zsdata(uap, uap->port.x_char);
431 		zssync(uap);
432 		uap->port.icount.tx++;
433 		uap->port.x_char = 0;
434 		return;
435 	}
436 
437 	if (uap->port.state == NULL)
438 		goto ack_tx_int;
439 	xmit = &uap->port.state->xmit;
440 	if (uart_circ_empty(xmit)) {
441 		uart_write_wakeup(&uap->port);
442 		goto ack_tx_int;
443 	}
444 	if (uart_tx_stopped(&uap->port))
445 		goto ack_tx_int;
446 
447 	uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
448 	write_zsdata(uap, xmit->buf[xmit->tail]);
449 	zssync(uap);
450 
451 	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
452 	uap->port.icount.tx++;
453 
454 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
455 		uart_write_wakeup(&uap->port);
456 
457 	return;
458 
459 ack_tx_int:
460 	write_zsreg(uap, R0, RES_Tx_P);
461 	zssync(uap);
462 }
463 
464 /* Hrm... we register that twice, fixme later.... */
465 static irqreturn_t pmz_interrupt(int irq, void *dev_id)
466 {
467 	struct uart_pmac_port *uap = dev_id;
468 	struct uart_pmac_port *uap_a;
469 	struct uart_pmac_port *uap_b;
470 	int rc = IRQ_NONE;
471 	struct tty_struct *tty;
472 	u8 r3;
473 
474 	uap_a = pmz_get_port_A(uap);
475 	uap_b = uap_a->mate;
476 
477 	spin_lock(&uap_a->port.lock);
478 	r3 = read_zsreg(uap_a, R3);
479 
480 #ifdef DEBUG_HARD
481 	pmz_debug("irq, r3: %x\n", r3);
482 #endif
483 	/* Channel A */
484 	tty = NULL;
485 	if (r3 & (CHAEXT | CHATxIP | CHARxIP)) {
486 		write_zsreg(uap_a, R0, RES_H_IUS);
487 		zssync(uap_a);
488 		if (r3 & CHAEXT)
489 			pmz_status_handle(uap_a);
490 		if (r3 & CHARxIP)
491 			tty = pmz_receive_chars(uap_a);
492 		if (r3 & CHATxIP)
493 			pmz_transmit_chars(uap_a);
494 		rc = IRQ_HANDLED;
495 	}
496 	spin_unlock(&uap_a->port.lock);
497 	if (tty != NULL)
498 		tty_flip_buffer_push(tty);
499 
500 	if (uap_b->node == NULL)
501 		goto out;
502 
503 	spin_lock(&uap_b->port.lock);
504 	tty = NULL;
505 	if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) {
506 		write_zsreg(uap_b, R0, RES_H_IUS);
507 		zssync(uap_b);
508 		if (r3 & CHBEXT)
509 			pmz_status_handle(uap_b);
510 		if (r3 & CHBRxIP)
511 			tty = pmz_receive_chars(uap_b);
512 		if (r3 & CHBTxIP)
513 			pmz_transmit_chars(uap_b);
514 		rc = IRQ_HANDLED;
515 	}
516 	spin_unlock(&uap_b->port.lock);
517 	if (tty != NULL)
518 		tty_flip_buffer_push(tty);
519 
520  out:
521 #ifdef DEBUG_HARD
522 	pmz_debug("irq done.\n");
523 #endif
524 	return rc;
525 }
526 
527 /*
528  * Peek the status register, lock not held by caller
529  */
530 static inline u8 pmz_peek_status(struct uart_pmac_port *uap)
531 {
532 	unsigned long flags;
533 	u8 status;
534 
535 	spin_lock_irqsave(&uap->port.lock, flags);
536 	status = read_zsreg(uap, R0);
537 	spin_unlock_irqrestore(&uap->port.lock, flags);
538 
539 	return status;
540 }
541 
542 /*
543  * Check if transmitter is empty
544  * The port lock is not held.
545  */
546 static unsigned int pmz_tx_empty(struct uart_port *port)
547 {
548 	struct uart_pmac_port *uap = to_pmz(port);
549 	unsigned char status;
550 
551 	if (ZS_IS_ASLEEP(uap) || uap->node == NULL)
552 		return TIOCSER_TEMT;
553 
554 	status = pmz_peek_status(to_pmz(port));
555 	if (status & Tx_BUF_EMP)
556 		return TIOCSER_TEMT;
557 	return 0;
558 }
559 
560 /*
561  * Set Modem Control (RTS & DTR) bits
562  * The port lock is held and interrupts are disabled.
563  * Note: Shall we really filter out RTS on external ports or
564  * should that be dealt at higher level only ?
565  */
566 static void pmz_set_mctrl(struct uart_port *port, unsigned int mctrl)
567 {
568 	struct uart_pmac_port *uap = to_pmz(port);
569 	unsigned char set_bits, clear_bits;
570 
571         /* Do nothing for irda for now... */
572 	if (ZS_IS_IRDA(uap))
573 		return;
574 	/* We get called during boot with a port not up yet */
575 	if (ZS_IS_ASLEEP(uap) ||
576 	    !(ZS_IS_OPEN(uap) || ZS_IS_CONS(uap)))
577 		return;
578 
579 	set_bits = clear_bits = 0;
580 
581 	if (ZS_IS_INTMODEM(uap)) {
582 		if (mctrl & TIOCM_RTS)
583 			set_bits |= RTS;
584 		else
585 			clear_bits |= RTS;
586 	}
587 	if (mctrl & TIOCM_DTR)
588 		set_bits |= DTR;
589 	else
590 		clear_bits |= DTR;
591 
592 	/* NOTE: Not subject to 'transmitter active' rule.  */
593 	uap->curregs[R5] |= set_bits;
594 	uap->curregs[R5] &= ~clear_bits;
595 	if (ZS_IS_ASLEEP(uap))
596 		return;
597 	write_zsreg(uap, R5, uap->curregs[R5]);
598 	pmz_debug("pmz_set_mctrl: set bits: %x, clear bits: %x -> %x\n",
599 		  set_bits, clear_bits, uap->curregs[R5]);
600 	zssync(uap);
601 }
602 
603 /*
604  * Get Modem Control bits (only the input ones, the core will
605  * or that with a cached value of the control ones)
606  * The port lock is held and interrupts are disabled.
607  */
608 static unsigned int pmz_get_mctrl(struct uart_port *port)
609 {
610 	struct uart_pmac_port *uap = to_pmz(port);
611 	unsigned char status;
612 	unsigned int ret;
613 
614 	if (ZS_IS_ASLEEP(uap) || uap->node == NULL)
615 		return 0;
616 
617 	status = read_zsreg(uap, R0);
618 
619 	ret = 0;
620 	if (status & DCD)
621 		ret |= TIOCM_CAR;
622 	if (status & SYNC_HUNT)
623 		ret |= TIOCM_DSR;
624 	if (!(status & CTS))
625 		ret |= TIOCM_CTS;
626 
627 	return ret;
628 }
629 
630 /*
631  * Stop TX side. Dealt like sunzilog at next Tx interrupt,
632  * though for DMA, we will have to do a bit more.
633  * The port lock is held and interrupts are disabled.
634  */
635 static void pmz_stop_tx(struct uart_port *port)
636 {
637 	to_pmz(port)->flags |= PMACZILOG_FLAG_TX_STOPPED;
638 }
639 
640 /*
641  * Kick the Tx side.
642  * The port lock is held and interrupts are disabled.
643  */
644 static void pmz_start_tx(struct uart_port *port)
645 {
646 	struct uart_pmac_port *uap = to_pmz(port);
647 	unsigned char status;
648 
649 	pmz_debug("pmz: start_tx()\n");
650 
651 	uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
652 	uap->flags &= ~PMACZILOG_FLAG_TX_STOPPED;
653 
654 	if (ZS_IS_ASLEEP(uap) || uap->node == NULL)
655 		return;
656 
657 	status = read_zsreg(uap, R0);
658 
659 	/* TX busy?  Just wait for the TX done interrupt.  */
660 	if (!(status & Tx_BUF_EMP))
661 		return;
662 
663 	/* Send the first character to jump-start the TX done
664 	 * IRQ sending engine.
665 	 */
666 	if (port->x_char) {
667 		write_zsdata(uap, port->x_char);
668 		zssync(uap);
669 		port->icount.tx++;
670 		port->x_char = 0;
671 	} else {
672 		struct circ_buf *xmit = &port->state->xmit;
673 
674 		write_zsdata(uap, xmit->buf[xmit->tail]);
675 		zssync(uap);
676 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
677 		port->icount.tx++;
678 
679 		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
680 			uart_write_wakeup(&uap->port);
681 	}
682 	pmz_debug("pmz: start_tx() done.\n");
683 }
684 
685 /*
686  * Stop Rx side, basically disable emitting of
687  * Rx interrupts on the port. We don't disable the rx
688  * side of the chip proper though
689  * The port lock is held.
690  */
691 static void pmz_stop_rx(struct uart_port *port)
692 {
693 	struct uart_pmac_port *uap = to_pmz(port);
694 
695 	if (ZS_IS_ASLEEP(uap) || uap->node == NULL)
696 		return;
697 
698 	pmz_debug("pmz: stop_rx()()\n");
699 
700 	/* Disable all RX interrupts.  */
701 	uap->curregs[R1] &= ~RxINT_MASK;
702 	pmz_maybe_update_regs(uap);
703 
704 	pmz_debug("pmz: stop_rx() done.\n");
705 }
706 
707 /*
708  * Enable modem status change interrupts
709  * The port lock is held.
710  */
711 static void pmz_enable_ms(struct uart_port *port)
712 {
713 	struct uart_pmac_port *uap = to_pmz(port);
714 	unsigned char new_reg;
715 
716 	if (ZS_IS_IRDA(uap) || uap->node == NULL)
717 		return;
718 	new_reg = uap->curregs[R15] | (DCDIE | SYNCIE | CTSIE);
719 	if (new_reg != uap->curregs[R15]) {
720 		uap->curregs[R15] = new_reg;
721 
722 		if (ZS_IS_ASLEEP(uap))
723 			return;
724 		/* NOTE: Not subject to 'transmitter active' rule. */
725 		write_zsreg(uap, R15, uap->curregs[R15]);
726 	}
727 }
728 
729 /*
730  * Control break state emission
731  * The port lock is not held.
732  */
733 static void pmz_break_ctl(struct uart_port *port, int break_state)
734 {
735 	struct uart_pmac_port *uap = to_pmz(port);
736 	unsigned char set_bits, clear_bits, new_reg;
737 	unsigned long flags;
738 
739 	if (uap->node == NULL)
740 		return;
741 	set_bits = clear_bits = 0;
742 
743 	if (break_state)
744 		set_bits |= SND_BRK;
745 	else
746 		clear_bits |= SND_BRK;
747 
748 	spin_lock_irqsave(&port->lock, flags);
749 
750 	new_reg = (uap->curregs[R5] | set_bits) & ~clear_bits;
751 	if (new_reg != uap->curregs[R5]) {
752 		uap->curregs[R5] = new_reg;
753 
754 		/* NOTE: Not subject to 'transmitter active' rule. */
755 		if (ZS_IS_ASLEEP(uap)) {
756 			spin_unlock_irqrestore(&port->lock, flags);
757 			return;
758 		}
759 		write_zsreg(uap, R5, uap->curregs[R5]);
760 	}
761 
762 	spin_unlock_irqrestore(&port->lock, flags);
763 }
764 
765 #ifdef CONFIG_PPC_PMAC
766 
767 /*
768  * Turn power on or off to the SCC and associated stuff
769  * (port drivers, modem, IR port, etc.)
770  * Returns the number of milliseconds we should wait before
771  * trying to use the port.
772  */
773 static int pmz_set_scc_power(struct uart_pmac_port *uap, int state)
774 {
775 	int delay = 0;
776 	int rc;
777 
778 	if (state) {
779 		rc = pmac_call_feature(
780 			PMAC_FTR_SCC_ENABLE, uap->node, uap->port_type, 1);
781 		pmz_debug("port power on result: %d\n", rc);
782 		if (ZS_IS_INTMODEM(uap)) {
783 			rc = pmac_call_feature(
784 				PMAC_FTR_MODEM_ENABLE, uap->node, 0, 1);
785 			delay = 2500;	/* wait for 2.5s before using */
786 			pmz_debug("modem power result: %d\n", rc);
787 		}
788 	} else {
789 		/* TODO: Make that depend on a timer, don't power down
790 		 * immediately
791 		 */
792 		if (ZS_IS_INTMODEM(uap)) {
793 			rc = pmac_call_feature(
794 				PMAC_FTR_MODEM_ENABLE, uap->node, 0, 0);
795 			pmz_debug("port power off result: %d\n", rc);
796 		}
797 		pmac_call_feature(PMAC_FTR_SCC_ENABLE, uap->node, uap->port_type, 0);
798 	}
799 	return delay;
800 }
801 
802 #else
803 
804 static int pmz_set_scc_power(struct uart_pmac_port *uap, int state)
805 {
806 	return 0;
807 }
808 
809 #endif /* !CONFIG_PPC_PMAC */
810 
811 /*
812  * FixZeroBug....Works around a bug in the SCC receving channel.
813  * Inspired from Darwin code, 15 Sept. 2000  -DanM
814  *
815  * The following sequence prevents a problem that is seen with O'Hare ASICs
816  * (most versions -- also with some Heathrow and Hydra ASICs) where a zero
817  * at the input to the receiver becomes 'stuck' and locks up the receiver.
818  * This problem can occur as a result of a zero bit at the receiver input
819  * coincident with any of the following events:
820  *
821  *	The SCC is initialized (hardware or software).
822  *	A framing error is detected.
823  *	The clocking option changes from synchronous or X1 asynchronous
824  *		clocking to X16, X32, or X64 asynchronous clocking.
825  *	The decoding mode is changed among NRZ, NRZI, FM0, or FM1.
826  *
827  * This workaround attempts to recover from the lockup condition by placing
828  * the SCC in synchronous loopback mode with a fast clock before programming
829  * any of the asynchronous modes.
830  */
831 static void pmz_fix_zero_bug_scc(struct uart_pmac_port *uap)
832 {
833 	write_zsreg(uap, 9, ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB);
834 	zssync(uap);
835 	udelay(10);
836 	write_zsreg(uap, 9, (ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB) | NV);
837 	zssync(uap);
838 
839 	write_zsreg(uap, 4, X1CLK | MONSYNC);
840 	write_zsreg(uap, 3, Rx8);
841 	write_zsreg(uap, 5, Tx8 | RTS);
842 	write_zsreg(uap, 9, NV);	/* Didn't we already do this? */
843 	write_zsreg(uap, 11, RCBR | TCBR);
844 	write_zsreg(uap, 12, 0);
845 	write_zsreg(uap, 13, 0);
846 	write_zsreg(uap, 14, (LOOPBAK | BRSRC));
847 	write_zsreg(uap, 14, (LOOPBAK | BRSRC | BRENAB));
848 	write_zsreg(uap, 3, Rx8 | RxENABLE);
849 	write_zsreg(uap, 0, RES_EXT_INT);
850 	write_zsreg(uap, 0, RES_EXT_INT);
851 	write_zsreg(uap, 0, RES_EXT_INT);	/* to kill some time */
852 
853 	/* The channel should be OK now, but it is probably receiving
854 	 * loopback garbage.
855 	 * Switch to asynchronous mode, disable the receiver,
856 	 * and discard everything in the receive buffer.
857 	 */
858 	write_zsreg(uap, 9, NV);
859 	write_zsreg(uap, 4, X16CLK | SB_MASK);
860 	write_zsreg(uap, 3, Rx8);
861 
862 	while (read_zsreg(uap, 0) & Rx_CH_AV) {
863 		(void)read_zsreg(uap, 8);
864 		write_zsreg(uap, 0, RES_EXT_INT);
865 		write_zsreg(uap, 0, ERR_RES);
866 	}
867 }
868 
869 /*
870  * Real startup routine, powers up the hardware and sets up
871  * the SCC. Returns a delay in ms where you need to wait before
872  * actually using the port, this is typically the internal modem
873  * powerup delay. This routine expect the lock to be taken.
874  */
875 static int __pmz_startup(struct uart_pmac_port *uap)
876 {
877 	int pwr_delay = 0;
878 
879 	memset(&uap->curregs, 0, sizeof(uap->curregs));
880 
881 	/* Power up the SCC & underlying hardware (modem/irda) */
882 	pwr_delay = pmz_set_scc_power(uap, 1);
883 
884 	/* Nice buggy HW ... */
885 	pmz_fix_zero_bug_scc(uap);
886 
887 	/* Reset the channel */
888 	uap->curregs[R9] = 0;
889 	write_zsreg(uap, 9, ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB);
890 	zssync(uap);
891 	udelay(10);
892 	write_zsreg(uap, 9, 0);
893 	zssync(uap);
894 
895 	/* Clear the interrupt registers */
896 	write_zsreg(uap, R1, 0);
897 	write_zsreg(uap, R0, ERR_RES);
898 	write_zsreg(uap, R0, ERR_RES);
899 	write_zsreg(uap, R0, RES_H_IUS);
900 	write_zsreg(uap, R0, RES_H_IUS);
901 
902 	/* Setup some valid baud rate */
903 	uap->curregs[R4] = X16CLK | SB1;
904 	uap->curregs[R3] = Rx8;
905 	uap->curregs[R5] = Tx8 | RTS;
906 	if (!ZS_IS_IRDA(uap))
907 		uap->curregs[R5] |= DTR;
908 	uap->curregs[R12] = 0;
909 	uap->curregs[R13] = 0;
910 	uap->curregs[R14] = BRENAB;
911 
912 	/* Clear handshaking, enable BREAK interrupts */
913 	uap->curregs[R15] = BRKIE;
914 
915 	/* Master interrupt enable */
916 	uap->curregs[R9] |= NV | MIE;
917 
918 	pmz_load_zsregs(uap, uap->curregs);
919 
920 	/* Enable receiver and transmitter.  */
921 	write_zsreg(uap, R3, uap->curregs[R3] |= RxENABLE);
922 	write_zsreg(uap, R5, uap->curregs[R5] |= TxENABLE);
923 
924 	/* Remember status for DCD/CTS changes */
925 	uap->prev_status = read_zsreg(uap, R0);
926 
927 	return pwr_delay;
928 }
929 
930 static void pmz_irda_reset(struct uart_pmac_port *uap)
931 {
932 	uap->curregs[R5] |= DTR;
933 	write_zsreg(uap, R5, uap->curregs[R5]);
934 	zssync(uap);
935 	mdelay(110);
936 	uap->curregs[R5] &= ~DTR;
937 	write_zsreg(uap, R5, uap->curregs[R5]);
938 	zssync(uap);
939 	mdelay(10);
940 }
941 
942 /*
943  * This is the "normal" startup routine, using the above one
944  * wrapped with the lock and doing a schedule delay
945  */
946 static int pmz_startup(struct uart_port *port)
947 {
948 	struct uart_pmac_port *uap = to_pmz(port);
949 	unsigned long flags;
950 	int pwr_delay = 0;
951 
952 	pmz_debug("pmz: startup()\n");
953 
954 	if (ZS_IS_ASLEEP(uap))
955 		return -EAGAIN;
956 	if (uap->node == NULL)
957 		return -ENODEV;
958 
959 	mutex_lock(&pmz_irq_mutex);
960 
961 	uap->flags |= PMACZILOG_FLAG_IS_OPEN;
962 
963 	/* A console is never powered down. Else, power up and
964 	 * initialize the chip
965 	 */
966 	if (!ZS_IS_CONS(uap)) {
967 		spin_lock_irqsave(&port->lock, flags);
968 		pwr_delay = __pmz_startup(uap);
969 		spin_unlock_irqrestore(&port->lock, flags);
970 	}
971 
972 	pmz_get_port_A(uap)->flags |= PMACZILOG_FLAG_IS_IRQ_ON;
973 	if (request_irq(uap->port.irq, pmz_interrupt, IRQF_SHARED,
974 			"SCC", uap)) {
975 		pmz_error("Unable to register zs interrupt handler.\n");
976 		pmz_set_scc_power(uap, 0);
977 		mutex_unlock(&pmz_irq_mutex);
978 		return -ENXIO;
979 	}
980 
981 	mutex_unlock(&pmz_irq_mutex);
982 
983 	/* Right now, we deal with delay by blocking here, I'll be
984 	 * smarter later on
985 	 */
986 	if (pwr_delay != 0) {
987 		pmz_debug("pmz: delaying %d ms\n", pwr_delay);
988 		msleep(pwr_delay);
989 	}
990 
991 	/* IrDA reset is done now */
992 	if (ZS_IS_IRDA(uap))
993 		pmz_irda_reset(uap);
994 
995 	/* Enable interrupts emission from the chip */
996 	spin_lock_irqsave(&port->lock, flags);
997 	uap->curregs[R1] |= INT_ALL_Rx | TxINT_ENAB;
998 	if (!ZS_IS_EXTCLK(uap))
999 		uap->curregs[R1] |= EXT_INT_ENAB;
1000 	write_zsreg(uap, R1, uap->curregs[R1]);
1001 	spin_unlock_irqrestore(&port->lock, flags);
1002 
1003 	pmz_debug("pmz: startup() done.\n");
1004 
1005 	return 0;
1006 }
1007 
1008 static void pmz_shutdown(struct uart_port *port)
1009 {
1010 	struct uart_pmac_port *uap = to_pmz(port);
1011 	unsigned long flags;
1012 
1013 	pmz_debug("pmz: shutdown()\n");
1014 
1015 	if (uap->node == NULL)
1016 		return;
1017 
1018 	mutex_lock(&pmz_irq_mutex);
1019 
1020 	/* Release interrupt handler */
1021 	free_irq(uap->port.irq, uap);
1022 
1023 	spin_lock_irqsave(&port->lock, flags);
1024 
1025 	uap->flags &= ~PMACZILOG_FLAG_IS_OPEN;
1026 
1027 	if (!ZS_IS_OPEN(uap->mate))
1028 		pmz_get_port_A(uap)->flags &= ~PMACZILOG_FLAG_IS_IRQ_ON;
1029 
1030 	/* Disable interrupts */
1031 	if (!ZS_IS_ASLEEP(uap)) {
1032 		uap->curregs[R1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
1033 		write_zsreg(uap, R1, uap->curregs[R1]);
1034 		zssync(uap);
1035 	}
1036 
1037 	if (ZS_IS_CONS(uap) || ZS_IS_ASLEEP(uap)) {
1038 		spin_unlock_irqrestore(&port->lock, flags);
1039 		mutex_unlock(&pmz_irq_mutex);
1040 		return;
1041 	}
1042 
1043 	/* Disable receiver and transmitter.  */
1044 	uap->curregs[R3] &= ~RxENABLE;
1045 	uap->curregs[R5] &= ~TxENABLE;
1046 
1047 	/* Disable all interrupts and BRK assertion.  */
1048 	uap->curregs[R5] &= ~SND_BRK;
1049 	pmz_maybe_update_regs(uap);
1050 
1051 	/* Shut the chip down */
1052 	pmz_set_scc_power(uap, 0);
1053 
1054 	spin_unlock_irqrestore(&port->lock, flags);
1055 
1056 	mutex_unlock(&pmz_irq_mutex);
1057 
1058 	pmz_debug("pmz: shutdown() done.\n");
1059 }
1060 
1061 /* Shared by TTY driver and serial console setup.  The port lock is held
1062  * and local interrupts are disabled.
1063  */
1064 static void pmz_convert_to_zs(struct uart_pmac_port *uap, unsigned int cflag,
1065 			      unsigned int iflag, unsigned long baud)
1066 {
1067 	int brg;
1068 
1069 	/* Switch to external clocking for IrDA high clock rates. That
1070 	 * code could be re-used for Midi interfaces with different
1071 	 * multipliers
1072 	 */
1073 	if (baud >= 115200 && ZS_IS_IRDA(uap)) {
1074 		uap->curregs[R4] = X1CLK;
1075 		uap->curregs[R11] = RCTRxCP | TCTRxCP;
1076 		uap->curregs[R14] = 0; /* BRG off */
1077 		uap->curregs[R12] = 0;
1078 		uap->curregs[R13] = 0;
1079 		uap->flags |= PMACZILOG_FLAG_IS_EXTCLK;
1080 	} else {
1081 		switch (baud) {
1082 		case ZS_CLOCK/16:	/* 230400 */
1083 			uap->curregs[R4] = X16CLK;
1084 			uap->curregs[R11] = 0;
1085 			uap->curregs[R14] = 0;
1086 			break;
1087 		case ZS_CLOCK/32:	/* 115200 */
1088 			uap->curregs[R4] = X32CLK;
1089 			uap->curregs[R11] = 0;
1090 			uap->curregs[R14] = 0;
1091 			break;
1092 		default:
1093 			uap->curregs[R4] = X16CLK;
1094 			uap->curregs[R11] = TCBR | RCBR;
1095 			brg = BPS_TO_BRG(baud, ZS_CLOCK / 16);
1096 			uap->curregs[R12] = (brg & 255);
1097 			uap->curregs[R13] = ((brg >> 8) & 255);
1098 			uap->curregs[R14] = BRENAB;
1099 		}
1100 		uap->flags &= ~PMACZILOG_FLAG_IS_EXTCLK;
1101 	}
1102 
1103 	/* Character size, stop bits, and parity. */
1104 	uap->curregs[3] &= ~RxN_MASK;
1105 	uap->curregs[5] &= ~TxN_MASK;
1106 
1107 	switch (cflag & CSIZE) {
1108 	case CS5:
1109 		uap->curregs[3] |= Rx5;
1110 		uap->curregs[5] |= Tx5;
1111 		uap->parity_mask = 0x1f;
1112 		break;
1113 	case CS6:
1114 		uap->curregs[3] |= Rx6;
1115 		uap->curregs[5] |= Tx6;
1116 		uap->parity_mask = 0x3f;
1117 		break;
1118 	case CS7:
1119 		uap->curregs[3] |= Rx7;
1120 		uap->curregs[5] |= Tx7;
1121 		uap->parity_mask = 0x7f;
1122 		break;
1123 	case CS8:
1124 	default:
1125 		uap->curregs[3] |= Rx8;
1126 		uap->curregs[5] |= Tx8;
1127 		uap->parity_mask = 0xff;
1128 		break;
1129 	};
1130 	uap->curregs[4] &= ~(SB_MASK);
1131 	if (cflag & CSTOPB)
1132 		uap->curregs[4] |= SB2;
1133 	else
1134 		uap->curregs[4] |= SB1;
1135 	if (cflag & PARENB)
1136 		uap->curregs[4] |= PAR_ENAB;
1137 	else
1138 		uap->curregs[4] &= ~PAR_ENAB;
1139 	if (!(cflag & PARODD))
1140 		uap->curregs[4] |= PAR_EVEN;
1141 	else
1142 		uap->curregs[4] &= ~PAR_EVEN;
1143 
1144 	uap->port.read_status_mask = Rx_OVR;
1145 	if (iflag & INPCK)
1146 		uap->port.read_status_mask |= CRC_ERR | PAR_ERR;
1147 	if (iflag & (BRKINT | PARMRK))
1148 		uap->port.read_status_mask |= BRK_ABRT;
1149 
1150 	uap->port.ignore_status_mask = 0;
1151 	if (iflag & IGNPAR)
1152 		uap->port.ignore_status_mask |= CRC_ERR | PAR_ERR;
1153 	if (iflag & IGNBRK) {
1154 		uap->port.ignore_status_mask |= BRK_ABRT;
1155 		if (iflag & IGNPAR)
1156 			uap->port.ignore_status_mask |= Rx_OVR;
1157 	}
1158 
1159 	if ((cflag & CREAD) == 0)
1160 		uap->port.ignore_status_mask = 0xff;
1161 }
1162 
1163 
1164 /*
1165  * Set the irda codec on the imac to the specified baud rate.
1166  */
1167 static void pmz_irda_setup(struct uart_pmac_port *uap, unsigned long *baud)
1168 {
1169 	u8 cmdbyte;
1170 	int t, version;
1171 
1172 	switch (*baud) {
1173 	/* SIR modes */
1174 	case 2400:
1175 		cmdbyte = 0x53;
1176 		break;
1177 	case 4800:
1178 		cmdbyte = 0x52;
1179 		break;
1180 	case 9600:
1181 		cmdbyte = 0x51;
1182 		break;
1183 	case 19200:
1184 		cmdbyte = 0x50;
1185 		break;
1186 	case 38400:
1187 		cmdbyte = 0x4f;
1188 		break;
1189 	case 57600:
1190 		cmdbyte = 0x4e;
1191 		break;
1192 	case 115200:
1193 		cmdbyte = 0x4d;
1194 		break;
1195 	/* The FIR modes aren't really supported at this point, how
1196 	 * do we select the speed ? via the FCR on KeyLargo ?
1197 	 */
1198 	case 1152000:
1199 		cmdbyte = 0;
1200 		break;
1201 	case 4000000:
1202 		cmdbyte = 0;
1203 		break;
1204 	default: /* 9600 */
1205 		cmdbyte = 0x51;
1206 		*baud = 9600;
1207 		break;
1208 	}
1209 
1210 	/* Wait for transmitter to drain */
1211 	t = 10000;
1212 	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0
1213 	       || (read_zsreg(uap, R1) & ALL_SNT) == 0) {
1214 		if (--t <= 0) {
1215 			pmz_error("transmitter didn't drain\n");
1216 			return;
1217 		}
1218 		udelay(10);
1219 	}
1220 
1221 	/* Drain the receiver too */
1222 	t = 100;
1223 	(void)read_zsdata(uap);
1224 	(void)read_zsdata(uap);
1225 	(void)read_zsdata(uap);
1226 	mdelay(10);
1227 	while (read_zsreg(uap, R0) & Rx_CH_AV) {
1228 		read_zsdata(uap);
1229 		mdelay(10);
1230 		if (--t <= 0) {
1231 			pmz_error("receiver didn't drain\n");
1232 			return;
1233 		}
1234 	}
1235 
1236 	/* Switch to command mode */
1237 	uap->curregs[R5] |= DTR;
1238 	write_zsreg(uap, R5, uap->curregs[R5]);
1239 	zssync(uap);
1240 	mdelay(1);
1241 
1242 	/* Switch SCC to 19200 */
1243 	pmz_convert_to_zs(uap, CS8, 0, 19200);
1244 	pmz_load_zsregs(uap, uap->curregs);
1245 	mdelay(1);
1246 
1247 	/* Write get_version command byte */
1248 	write_zsdata(uap, 1);
1249 	t = 5000;
1250 	while ((read_zsreg(uap, R0) & Rx_CH_AV) == 0) {
1251 		if (--t <= 0) {
1252 			pmz_error("irda_setup timed out on get_version byte\n");
1253 			goto out;
1254 		}
1255 		udelay(10);
1256 	}
1257 	version = read_zsdata(uap);
1258 
1259 	if (version < 4) {
1260 		pmz_info("IrDA: dongle version %d not supported\n", version);
1261 		goto out;
1262 	}
1263 
1264 	/* Send speed mode */
1265 	write_zsdata(uap, cmdbyte);
1266 	t = 5000;
1267 	while ((read_zsreg(uap, R0) & Rx_CH_AV) == 0) {
1268 		if (--t <= 0) {
1269 			pmz_error("irda_setup timed out on speed mode byte\n");
1270 			goto out;
1271 		}
1272 		udelay(10);
1273 	}
1274 	t = read_zsdata(uap);
1275 	if (t != cmdbyte)
1276 		pmz_error("irda_setup speed mode byte = %x (%x)\n", t, cmdbyte);
1277 
1278 	pmz_info("IrDA setup for %ld bps, dongle version: %d\n",
1279 		 *baud, version);
1280 
1281 	(void)read_zsdata(uap);
1282 	(void)read_zsdata(uap);
1283 	(void)read_zsdata(uap);
1284 
1285  out:
1286 	/* Switch back to data mode */
1287 	uap->curregs[R5] &= ~DTR;
1288 	write_zsreg(uap, R5, uap->curregs[R5]);
1289 	zssync(uap);
1290 
1291 	(void)read_zsdata(uap);
1292 	(void)read_zsdata(uap);
1293 	(void)read_zsdata(uap);
1294 }
1295 
1296 
1297 static void __pmz_set_termios(struct uart_port *port, struct ktermios *termios,
1298 			      struct ktermios *old)
1299 {
1300 	struct uart_pmac_port *uap = to_pmz(port);
1301 	unsigned long baud;
1302 
1303 	pmz_debug("pmz: set_termios()\n");
1304 
1305 	if (ZS_IS_ASLEEP(uap))
1306 		return;
1307 
1308 	memcpy(&uap->termios_cache, termios, sizeof(struct ktermios));
1309 
1310 	/* XXX Check which revs of machines actually allow 1 and 4Mb speeds
1311 	 * on the IR dongle. Note that the IRTTY driver currently doesn't know
1312 	 * about the FIR mode and high speed modes. So these are unused. For
1313 	 * implementing proper support for these, we should probably add some
1314 	 * DMA as well, at least on the Rx side, which isn't a simple thing
1315 	 * at this point.
1316 	 */
1317 	if (ZS_IS_IRDA(uap)) {
1318 		/* Calc baud rate */
1319 		baud = uart_get_baud_rate(port, termios, old, 1200, 4000000);
1320 		pmz_debug("pmz: switch IRDA to %ld bauds\n", baud);
1321 		/* Cet the irda codec to the right rate */
1322 		pmz_irda_setup(uap, &baud);
1323 		/* Set final baud rate */
1324 		pmz_convert_to_zs(uap, termios->c_cflag, termios->c_iflag, baud);
1325 		pmz_load_zsregs(uap, uap->curregs);
1326 		zssync(uap);
1327 	} else {
1328 		baud = uart_get_baud_rate(port, termios, old, 1200, 230400);
1329 		pmz_convert_to_zs(uap, termios->c_cflag, termios->c_iflag, baud);
1330 		/* Make sure modem status interrupts are correctly configured */
1331 		if (UART_ENABLE_MS(&uap->port, termios->c_cflag)) {
1332 			uap->curregs[R15] |= DCDIE | SYNCIE | CTSIE;
1333 			uap->flags |= PMACZILOG_FLAG_MODEM_STATUS;
1334 		} else {
1335 			uap->curregs[R15] &= ~(DCDIE | SYNCIE | CTSIE);
1336 			uap->flags &= ~PMACZILOG_FLAG_MODEM_STATUS;
1337 		}
1338 
1339 		/* Load registers to the chip */
1340 		pmz_maybe_update_regs(uap);
1341 	}
1342 	uart_update_timeout(port, termios->c_cflag, baud);
1343 
1344 	pmz_debug("pmz: set_termios() done.\n");
1345 }
1346 
1347 /* The port lock is not held.  */
1348 static void pmz_set_termios(struct uart_port *port, struct ktermios *termios,
1349 			    struct ktermios *old)
1350 {
1351 	struct uart_pmac_port *uap = to_pmz(port);
1352 	unsigned long flags;
1353 
1354 	spin_lock_irqsave(&port->lock, flags);
1355 
1356 	/* Disable IRQs on the port */
1357 	uap->curregs[R1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
1358 	write_zsreg(uap, R1, uap->curregs[R1]);
1359 
1360 	/* Setup new port configuration */
1361 	__pmz_set_termios(port, termios, old);
1362 
1363 	/* Re-enable IRQs on the port */
1364 	if (ZS_IS_OPEN(uap)) {
1365 		uap->curregs[R1] |= INT_ALL_Rx | TxINT_ENAB;
1366 		if (!ZS_IS_EXTCLK(uap))
1367 			uap->curregs[R1] |= EXT_INT_ENAB;
1368 		write_zsreg(uap, R1, uap->curregs[R1]);
1369 	}
1370 	spin_unlock_irqrestore(&port->lock, flags);
1371 }
1372 
1373 static const char *pmz_type(struct uart_port *port)
1374 {
1375 	struct uart_pmac_port *uap = to_pmz(port);
1376 
1377 	if (ZS_IS_IRDA(uap))
1378 		return "Z85c30 ESCC - Infrared port";
1379 	else if (ZS_IS_INTMODEM(uap))
1380 		return "Z85c30 ESCC - Internal modem";
1381 	return "Z85c30 ESCC - Serial port";
1382 }
1383 
1384 /* We do not request/release mappings of the registers here, this
1385  * happens at early serial probe time.
1386  */
1387 static void pmz_release_port(struct uart_port *port)
1388 {
1389 }
1390 
1391 static int pmz_request_port(struct uart_port *port)
1392 {
1393 	return 0;
1394 }
1395 
1396 /* These do not need to do anything interesting either.  */
1397 static void pmz_config_port(struct uart_port *port, int flags)
1398 {
1399 }
1400 
1401 /* We do not support letting the user mess with the divisor, IRQ, etc. */
1402 static int pmz_verify_port(struct uart_port *port, struct serial_struct *ser)
1403 {
1404 	return -EINVAL;
1405 }
1406 
1407 #ifdef CONFIG_CONSOLE_POLL
1408 
1409 static int pmz_poll_get_char(struct uart_port *port)
1410 {
1411 	struct uart_pmac_port *uap = (struct uart_pmac_port *)port;
1412 
1413 	while ((read_zsreg(uap, R0) & Rx_CH_AV) == 0)
1414 		udelay(5);
1415 	return read_zsdata(uap);
1416 }
1417 
1418 static void pmz_poll_put_char(struct uart_port *port, unsigned char c)
1419 {
1420 	struct uart_pmac_port *uap = (struct uart_pmac_port *)port;
1421 
1422 	/* Wait for the transmit buffer to empty. */
1423 	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0)
1424 		udelay(5);
1425 	write_zsdata(uap, c);
1426 }
1427 
1428 #endif /* CONFIG_CONSOLE_POLL */
1429 
1430 static struct uart_ops pmz_pops = {
1431 	.tx_empty	=	pmz_tx_empty,
1432 	.set_mctrl	=	pmz_set_mctrl,
1433 	.get_mctrl	=	pmz_get_mctrl,
1434 	.stop_tx	=	pmz_stop_tx,
1435 	.start_tx	=	pmz_start_tx,
1436 	.stop_rx	=	pmz_stop_rx,
1437 	.enable_ms	=	pmz_enable_ms,
1438 	.break_ctl	=	pmz_break_ctl,
1439 	.startup	=	pmz_startup,
1440 	.shutdown	=	pmz_shutdown,
1441 	.set_termios	=	pmz_set_termios,
1442 	.type		=	pmz_type,
1443 	.release_port	=	pmz_release_port,
1444 	.request_port	=	pmz_request_port,
1445 	.config_port	=	pmz_config_port,
1446 	.verify_port	=	pmz_verify_port,
1447 #ifdef CONFIG_CONSOLE_POLL
1448 	.poll_get_char	=	pmz_poll_get_char,
1449 	.poll_put_char	=	pmz_poll_put_char,
1450 #endif
1451 };
1452 
1453 #ifdef CONFIG_PPC_PMAC
1454 
1455 /*
1456  * Setup one port structure after probing, HW is down at this point,
1457  * Unlike sunzilog, we don't need to pre-init the spinlock as we don't
1458  * register our console before uart_add_one_port() is called
1459  */
1460 static int __init pmz_init_port(struct uart_pmac_port *uap)
1461 {
1462 	struct device_node *np = uap->node;
1463 	const char *conn;
1464 	const struct slot_names_prop {
1465 		int	count;
1466 		char	name[1];
1467 	} *slots;
1468 	int len;
1469 	struct resource r_ports, r_rxdma, r_txdma;
1470 
1471 	/*
1472 	 * Request & map chip registers
1473 	 */
1474 	if (of_address_to_resource(np, 0, &r_ports))
1475 		return -ENODEV;
1476 	uap->port.mapbase = r_ports.start;
1477 	uap->port.membase = ioremap(uap->port.mapbase, 0x1000);
1478 
1479 	uap->control_reg = uap->port.membase;
1480 	uap->data_reg = uap->control_reg + 0x10;
1481 
1482 	/*
1483 	 * Request & map DBDMA registers
1484 	 */
1485 #ifdef HAS_DBDMA
1486 	if (of_address_to_resource(np, 1, &r_txdma) == 0 &&
1487 	    of_address_to_resource(np, 2, &r_rxdma) == 0)
1488 		uap->flags |= PMACZILOG_FLAG_HAS_DMA;
1489 #else
1490 	memset(&r_txdma, 0, sizeof(struct resource));
1491 	memset(&r_rxdma, 0, sizeof(struct resource));
1492 #endif
1493 	if (ZS_HAS_DMA(uap)) {
1494 		uap->tx_dma_regs = ioremap(r_txdma.start, 0x100);
1495 		if (uap->tx_dma_regs == NULL) {
1496 			uap->flags &= ~PMACZILOG_FLAG_HAS_DMA;
1497 			goto no_dma;
1498 		}
1499 		uap->rx_dma_regs = ioremap(r_rxdma.start, 0x100);
1500 		if (uap->rx_dma_regs == NULL) {
1501 			iounmap(uap->tx_dma_regs);
1502 			uap->tx_dma_regs = NULL;
1503 			uap->flags &= ~PMACZILOG_FLAG_HAS_DMA;
1504 			goto no_dma;
1505 		}
1506 		uap->tx_dma_irq = irq_of_parse_and_map(np, 1);
1507 		uap->rx_dma_irq = irq_of_parse_and_map(np, 2);
1508 	}
1509 no_dma:
1510 
1511 	/*
1512 	 * Detect port type
1513 	 */
1514 	if (of_device_is_compatible(np, "cobalt"))
1515 		uap->flags |= PMACZILOG_FLAG_IS_INTMODEM;
1516 	conn = of_get_property(np, "AAPL,connector", &len);
1517 	if (conn && (strcmp(conn, "infrared") == 0))
1518 		uap->flags |= PMACZILOG_FLAG_IS_IRDA;
1519 	uap->port_type = PMAC_SCC_ASYNC;
1520 	/* 1999 Powerbook G3 has slot-names property instead */
1521 	slots = of_get_property(np, "slot-names", &len);
1522 	if (slots && slots->count > 0) {
1523 		if (strcmp(slots->name, "IrDA") == 0)
1524 			uap->flags |= PMACZILOG_FLAG_IS_IRDA;
1525 		else if (strcmp(slots->name, "Modem") == 0)
1526 			uap->flags |= PMACZILOG_FLAG_IS_INTMODEM;
1527 	}
1528 	if (ZS_IS_IRDA(uap))
1529 		uap->port_type = PMAC_SCC_IRDA;
1530 	if (ZS_IS_INTMODEM(uap)) {
1531 		struct device_node* i2c_modem =
1532 			of_find_node_by_name(NULL, "i2c-modem");
1533 		if (i2c_modem) {
1534 			const char* mid =
1535 				of_get_property(i2c_modem, "modem-id", NULL);
1536 			if (mid) switch(*mid) {
1537 			case 0x04 :
1538 			case 0x05 :
1539 			case 0x07 :
1540 			case 0x08 :
1541 			case 0x0b :
1542 			case 0x0c :
1543 				uap->port_type = PMAC_SCC_I2S1;
1544 			}
1545 			printk(KERN_INFO "pmac_zilog: i2c-modem detected, id: %d\n",
1546 				mid ? (*mid) : 0);
1547 			of_node_put(i2c_modem);
1548 		} else {
1549 			printk(KERN_INFO "pmac_zilog: serial modem detected\n");
1550 		}
1551 	}
1552 
1553 	/*
1554 	 * Init remaining bits of "port" structure
1555 	 */
1556 	uap->port.iotype = UPIO_MEM;
1557 	uap->port.irq = irq_of_parse_and_map(np, 0);
1558 	uap->port.uartclk = ZS_CLOCK;
1559 	uap->port.fifosize = 1;
1560 	uap->port.ops = &pmz_pops;
1561 	uap->port.type = PORT_PMAC_ZILOG;
1562 	uap->port.flags = 0;
1563 
1564 	/*
1565 	 * Fixup for the port on Gatwick for which the device-tree has
1566 	 * missing interrupts. Normally, the macio_dev would contain
1567 	 * fixed up interrupt info, but we use the device-tree directly
1568 	 * here due to early probing so we need the fixup too.
1569 	 */
1570 	if (uap->port.irq == NO_IRQ &&
1571 	    np->parent && np->parent->parent &&
1572 	    of_device_is_compatible(np->parent->parent, "gatwick")) {
1573 		/* IRQs on gatwick are offset by 64 */
1574 		uap->port.irq = irq_create_mapping(NULL, 64 + 15);
1575 		uap->tx_dma_irq = irq_create_mapping(NULL, 64 + 4);
1576 		uap->rx_dma_irq = irq_create_mapping(NULL, 64 + 5);
1577 	}
1578 
1579 	/* Setup some valid baud rate information in the register
1580 	 * shadows so we don't write crap there before baud rate is
1581 	 * first initialized.
1582 	 */
1583 	pmz_convert_to_zs(uap, CS8, 0, 9600);
1584 
1585 	return 0;
1586 }
1587 
1588 /*
1589  * Get rid of a port on module removal
1590  */
1591 static void pmz_dispose_port(struct uart_pmac_port *uap)
1592 {
1593 	struct device_node *np;
1594 
1595 	np = uap->node;
1596 	iounmap(uap->rx_dma_regs);
1597 	iounmap(uap->tx_dma_regs);
1598 	iounmap(uap->control_reg);
1599 	uap->node = NULL;
1600 	of_node_put(np);
1601 	memset(uap, 0, sizeof(struct uart_pmac_port));
1602 }
1603 
1604 /*
1605  * Called upon match with an escc node in the device-tree.
1606  */
1607 static int pmz_attach(struct macio_dev *mdev, const struct of_device_id *match)
1608 {
1609 	int i;
1610 
1611 	/* Iterate the pmz_ports array to find a matching entry
1612 	 */
1613 	for (i = 0; i < MAX_ZS_PORTS; i++)
1614 		if (pmz_ports[i].node == mdev->ofdev.dev.of_node) {
1615 			struct uart_pmac_port *uap = &pmz_ports[i];
1616 
1617 			uap->dev = mdev;
1618 			dev_set_drvdata(&mdev->ofdev.dev, uap);
1619 			if (macio_request_resources(uap->dev, "pmac_zilog"))
1620 				printk(KERN_WARNING "%s: Failed to request resource"
1621 				       ", port still active\n",
1622 				       uap->node->name);
1623 			else
1624 				uap->flags |= PMACZILOG_FLAG_RSRC_REQUESTED;
1625 			return 0;
1626 		}
1627 	return -ENODEV;
1628 }
1629 
1630 /*
1631  * That one should not be called, macio isn't really a hotswap device,
1632  * we don't expect one of those serial ports to go away...
1633  */
1634 static int pmz_detach(struct macio_dev *mdev)
1635 {
1636 	struct uart_pmac_port	*uap = dev_get_drvdata(&mdev->ofdev.dev);
1637 
1638 	if (!uap)
1639 		return -ENODEV;
1640 
1641 	if (uap->flags & PMACZILOG_FLAG_RSRC_REQUESTED) {
1642 		macio_release_resources(uap->dev);
1643 		uap->flags &= ~PMACZILOG_FLAG_RSRC_REQUESTED;
1644 	}
1645 	dev_set_drvdata(&mdev->ofdev.dev, NULL);
1646 	uap->dev = NULL;
1647 
1648 	return 0;
1649 }
1650 
1651 
1652 static int pmz_suspend(struct macio_dev *mdev, pm_message_t pm_state)
1653 {
1654 	struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev);
1655 	struct uart_state *state;
1656 	unsigned long flags;
1657 
1658 	if (uap == NULL) {
1659 		printk("HRM... pmz_suspend with NULL uap\n");
1660 		return 0;
1661 	}
1662 
1663 	if (pm_state.event == mdev->ofdev.dev.power.power_state.event)
1664 		return 0;
1665 
1666 	pmz_debug("suspend, switching to state %d\n", pm_state.event);
1667 
1668 	state = pmz_uart_reg.state + uap->port.line;
1669 
1670 	mutex_lock(&pmz_irq_mutex);
1671 	mutex_lock(&state->port.mutex);
1672 
1673 	spin_lock_irqsave(&uap->port.lock, flags);
1674 
1675 	if (ZS_IS_OPEN(uap) || ZS_IS_CONS(uap)) {
1676 		/* Disable receiver and transmitter.  */
1677 		uap->curregs[R3] &= ~RxENABLE;
1678 		uap->curregs[R5] &= ~TxENABLE;
1679 
1680 		/* Disable all interrupts and BRK assertion.  */
1681 		uap->curregs[R1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
1682 		uap->curregs[R5] &= ~SND_BRK;
1683 		pmz_load_zsregs(uap, uap->curregs);
1684 		uap->flags |= PMACZILOG_FLAG_IS_ASLEEP;
1685 		mb();
1686 	}
1687 
1688 	spin_unlock_irqrestore(&uap->port.lock, flags);
1689 
1690 	if (ZS_IS_OPEN(uap) || ZS_IS_OPEN(uap->mate))
1691 		if (ZS_IS_ASLEEP(uap->mate) && ZS_IS_IRQ_ON(pmz_get_port_A(uap))) {
1692 			pmz_get_port_A(uap)->flags &= ~PMACZILOG_FLAG_IS_IRQ_ON;
1693 			disable_irq(uap->port.irq);
1694 		}
1695 
1696 	if (ZS_IS_CONS(uap))
1697 		uap->port.cons->flags &= ~CON_ENABLED;
1698 
1699 	/* Shut the chip down */
1700 	pmz_set_scc_power(uap, 0);
1701 
1702 	mutex_unlock(&state->port.mutex);
1703 	mutex_unlock(&pmz_irq_mutex);
1704 
1705 	pmz_debug("suspend, switching complete\n");
1706 
1707 	mdev->ofdev.dev.power.power_state = pm_state;
1708 
1709 	return 0;
1710 }
1711 
1712 
1713 static int pmz_resume(struct macio_dev *mdev)
1714 {
1715 	struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev);
1716 	struct uart_state *state;
1717 	unsigned long flags;
1718 	int pwr_delay = 0;
1719 
1720 	if (uap == NULL)
1721 		return 0;
1722 
1723 	if (mdev->ofdev.dev.power.power_state.event == PM_EVENT_ON)
1724 		return 0;
1725 
1726 	pmz_debug("resume, switching to state 0\n");
1727 
1728 	state = pmz_uart_reg.state + uap->port.line;
1729 
1730 	mutex_lock(&pmz_irq_mutex);
1731 	mutex_lock(&state->port.mutex);
1732 
1733 	spin_lock_irqsave(&uap->port.lock, flags);
1734 	if (!ZS_IS_OPEN(uap) && !ZS_IS_CONS(uap)) {
1735 		spin_unlock_irqrestore(&uap->port.lock, flags);
1736 		goto bail;
1737 	}
1738 	pwr_delay = __pmz_startup(uap);
1739 
1740 	/* Take care of config that may have changed while asleep */
1741 	__pmz_set_termios(&uap->port, &uap->termios_cache, NULL);
1742 
1743 	if (ZS_IS_OPEN(uap)) {
1744 		/* Enable interrupts */
1745 		uap->curregs[R1] |= INT_ALL_Rx | TxINT_ENAB;
1746 		if (!ZS_IS_EXTCLK(uap))
1747 			uap->curregs[R1] |= EXT_INT_ENAB;
1748 		write_zsreg(uap, R1, uap->curregs[R1]);
1749 	}
1750 
1751 	spin_unlock_irqrestore(&uap->port.lock, flags);
1752 
1753 	if (ZS_IS_CONS(uap))
1754 		uap->port.cons->flags |= CON_ENABLED;
1755 
1756 	/* Re-enable IRQ on the controller */
1757 	if (ZS_IS_OPEN(uap) && !ZS_IS_IRQ_ON(pmz_get_port_A(uap))) {
1758 		pmz_get_port_A(uap)->flags |= PMACZILOG_FLAG_IS_IRQ_ON;
1759 		enable_irq(uap->port.irq);
1760 	}
1761 
1762  bail:
1763 	mutex_unlock(&state->port.mutex);
1764 	mutex_unlock(&pmz_irq_mutex);
1765 
1766 	/* Right now, we deal with delay by blocking here, I'll be
1767 	 * smarter later on
1768 	 */
1769 	if (pwr_delay != 0) {
1770 		pmz_debug("pmz: delaying %d ms\n", pwr_delay);
1771 		msleep(pwr_delay);
1772 	}
1773 
1774 	pmz_debug("resume, switching complete\n");
1775 
1776 	mdev->ofdev.dev.power.power_state.event = PM_EVENT_ON;
1777 
1778 	return 0;
1779 }
1780 
1781 /*
1782  * Probe all ports in the system and build the ports array, we register
1783  * with the serial layer at this point, the macio-type probing is only
1784  * used later to "attach" to the sysfs tree so we get power management
1785  * events
1786  */
1787 static int __init pmz_probe(void)
1788 {
1789 	struct device_node	*node_p, *node_a, *node_b, *np;
1790 	int			count = 0;
1791 	int			rc;
1792 
1793 	/*
1794 	 * Find all escc chips in the system
1795 	 */
1796 	node_p = of_find_node_by_name(NULL, "escc");
1797 	while (node_p) {
1798 		/*
1799 		 * First get channel A/B node pointers
1800 		 *
1801 		 * TODO: Add routines with proper locking to do that...
1802 		 */
1803 		node_a = node_b = NULL;
1804 		for (np = NULL; (np = of_get_next_child(node_p, np)) != NULL;) {
1805 			if (strncmp(np->name, "ch-a", 4) == 0)
1806 				node_a = of_node_get(np);
1807 			else if (strncmp(np->name, "ch-b", 4) == 0)
1808 				node_b = of_node_get(np);
1809 		}
1810 		if (!node_a && !node_b) {
1811 			of_node_put(node_a);
1812 			of_node_put(node_b);
1813 			printk(KERN_ERR "pmac_zilog: missing node %c for escc %s\n",
1814 				(!node_a) ? 'a' : 'b', node_p->full_name);
1815 			goto next;
1816 		}
1817 
1818 		/*
1819 		 * Fill basic fields in the port structures
1820 		 */
1821 		pmz_ports[count].mate		= &pmz_ports[count+1];
1822 		pmz_ports[count+1].mate		= &pmz_ports[count];
1823 		pmz_ports[count].flags		= PMACZILOG_FLAG_IS_CHANNEL_A;
1824 		pmz_ports[count].node		= node_a;
1825 		pmz_ports[count+1].node		= node_b;
1826 		pmz_ports[count].port.line	= count;
1827 		pmz_ports[count+1].port.line	= count+1;
1828 
1829 		/*
1830 		 * Setup the ports for real
1831 		 */
1832 		rc = pmz_init_port(&pmz_ports[count]);
1833 		if (rc == 0 && node_b != NULL)
1834 			rc = pmz_init_port(&pmz_ports[count+1]);
1835 		if (rc != 0) {
1836 			of_node_put(node_a);
1837 			of_node_put(node_b);
1838 			memset(&pmz_ports[count], 0, sizeof(struct uart_pmac_port));
1839 			memset(&pmz_ports[count+1], 0, sizeof(struct uart_pmac_port));
1840 			goto next;
1841 		}
1842 		count += 2;
1843 next:
1844 		node_p = of_find_node_by_name(node_p, "escc");
1845 	}
1846 	pmz_ports_count = count;
1847 
1848 	return 0;
1849 }
1850 
1851 #else
1852 
1853 extern struct platform_device scc_a_pdev, scc_b_pdev;
1854 
1855 static int __init pmz_init_port(struct uart_pmac_port *uap)
1856 {
1857 	struct resource *r_ports;
1858 	int irq;
1859 
1860 	r_ports = platform_get_resource(uap->node, IORESOURCE_MEM, 0);
1861 	irq = platform_get_irq(uap->node, 0);
1862 	if (!r_ports || !irq)
1863 		return -ENODEV;
1864 
1865 	uap->port.mapbase  = r_ports->start;
1866 	uap->port.membase  = (unsigned char __iomem *) r_ports->start;
1867 	uap->port.iotype   = UPIO_MEM;
1868 	uap->port.irq      = irq;
1869 	uap->port.uartclk  = ZS_CLOCK;
1870 	uap->port.fifosize = 1;
1871 	uap->port.ops      = &pmz_pops;
1872 	uap->port.type     = PORT_PMAC_ZILOG;
1873 	uap->port.flags    = 0;
1874 
1875 	uap->control_reg   = uap->port.membase;
1876 	uap->data_reg      = uap->control_reg + 4;
1877 	uap->port_type     = 0;
1878 
1879 	pmz_convert_to_zs(uap, CS8, 0, 9600);
1880 
1881 	return 0;
1882 }
1883 
1884 static int __init pmz_probe(void)
1885 {
1886 	int err;
1887 
1888 	pmz_ports_count = 0;
1889 
1890 	pmz_ports[0].mate      = &pmz_ports[1];
1891 	pmz_ports[0].port.line = 0;
1892 	pmz_ports[0].flags     = PMACZILOG_FLAG_IS_CHANNEL_A;
1893 	pmz_ports[0].node      = &scc_a_pdev;
1894 	err = pmz_init_port(&pmz_ports[0]);
1895 	if (err)
1896 		return err;
1897 	pmz_ports_count++;
1898 
1899 	pmz_ports[1].mate      = &pmz_ports[0];
1900 	pmz_ports[1].port.line = 1;
1901 	pmz_ports[1].flags     = 0;
1902 	pmz_ports[1].node      = &scc_b_pdev;
1903 	err = pmz_init_port(&pmz_ports[1]);
1904 	if (err)
1905 		return err;
1906 	pmz_ports_count++;
1907 
1908 	return 0;
1909 }
1910 
1911 static void pmz_dispose_port(struct uart_pmac_port *uap)
1912 {
1913 	memset(uap, 0, sizeof(struct uart_pmac_port));
1914 }
1915 
1916 static int __init pmz_attach(struct platform_device *pdev)
1917 {
1918 	int i;
1919 
1920 	for (i = 0; i < pmz_ports_count; i++)
1921 		if (pmz_ports[i].node == pdev)
1922 			return 0;
1923 	return -ENODEV;
1924 }
1925 
1926 static int __exit pmz_detach(struct platform_device *pdev)
1927 {
1928 	return 0;
1929 }
1930 
1931 #endif /* !CONFIG_PPC_PMAC */
1932 
1933 #ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
1934 
1935 static void pmz_console_write(struct console *con, const char *s, unsigned int count);
1936 static int __init pmz_console_setup(struct console *co, char *options);
1937 
1938 static struct console pmz_console = {
1939 	.name	=	PMACZILOG_NAME,
1940 	.write	=	pmz_console_write,
1941 	.device	=	uart_console_device,
1942 	.setup	=	pmz_console_setup,
1943 	.flags	=	CON_PRINTBUFFER,
1944 	.index	=	-1,
1945 	.data   =	&pmz_uart_reg,
1946 };
1947 
1948 #define PMACZILOG_CONSOLE	&pmz_console
1949 #else /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
1950 #define PMACZILOG_CONSOLE	(NULL)
1951 #endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
1952 
1953 /*
1954  * Register the driver, console driver and ports with the serial
1955  * core
1956  */
1957 static int __init pmz_register(void)
1958 {
1959 	int i, rc;
1960 
1961 	pmz_uart_reg.nr = pmz_ports_count;
1962 	pmz_uart_reg.cons = PMACZILOG_CONSOLE;
1963 
1964 	/*
1965 	 * Register this driver with the serial core
1966 	 */
1967 	rc = uart_register_driver(&pmz_uart_reg);
1968 	if (rc)
1969 		return rc;
1970 
1971 	/*
1972 	 * Register each port with the serial core
1973 	 */
1974 	for (i = 0; i < pmz_ports_count; i++) {
1975 		struct uart_pmac_port *uport = &pmz_ports[i];
1976 		/* NULL node may happen on wallstreet */
1977 		if (uport->node != NULL)
1978 			rc = uart_add_one_port(&pmz_uart_reg, &uport->port);
1979 		if (rc)
1980 			goto err_out;
1981 	}
1982 
1983 	return 0;
1984 err_out:
1985 	while (i-- > 0) {
1986 		struct uart_pmac_port *uport = &pmz_ports[i];
1987 		uart_remove_one_port(&pmz_uart_reg, &uport->port);
1988 	}
1989 	uart_unregister_driver(&pmz_uart_reg);
1990 	return rc;
1991 }
1992 
1993 #ifdef CONFIG_PPC_PMAC
1994 
1995 static struct of_device_id pmz_match[] =
1996 {
1997 	{
1998 	.name		= "ch-a",
1999 	},
2000 	{
2001 	.name		= "ch-b",
2002 	},
2003 	{},
2004 };
2005 MODULE_DEVICE_TABLE (of, pmz_match);
2006 
2007 static struct macio_driver pmz_driver = {
2008 	.driver = {
2009 		.name 		= "pmac_zilog",
2010 		.owner		= THIS_MODULE,
2011 		.of_match_table	= pmz_match,
2012 	},
2013 	.probe		= pmz_attach,
2014 	.remove		= pmz_detach,
2015 	.suspend	= pmz_suspend,
2016 	.resume		= pmz_resume,
2017 };
2018 
2019 #else
2020 
2021 static struct platform_driver pmz_driver = {
2022 	.remove		= __exit_p(pmz_detach),
2023 	.driver		= {
2024 		.name		= "scc",
2025 		.owner		= THIS_MODULE,
2026 	},
2027 };
2028 
2029 #endif /* !CONFIG_PPC_PMAC */
2030 
2031 static int __init init_pmz(void)
2032 {
2033 	int rc, i;
2034 	printk(KERN_INFO "%s\n", version);
2035 
2036 	/*
2037 	 * First, we need to do a direct OF-based probe pass. We
2038 	 * do that because we want serial console up before the
2039 	 * macio stuffs calls us back, and since that makes it
2040 	 * easier to pass the proper number of channels to
2041 	 * uart_register_driver()
2042 	 */
2043 	if (pmz_ports_count == 0)
2044 		pmz_probe();
2045 
2046 	/*
2047 	 * Bail early if no port found
2048 	 */
2049 	if (pmz_ports_count == 0)
2050 		return -ENODEV;
2051 
2052 	/*
2053 	 * Now we register with the serial layer
2054 	 */
2055 	rc = pmz_register();
2056 	if (rc) {
2057 		printk(KERN_ERR
2058 			"pmac_zilog: Error registering serial device, disabling pmac_zilog.\n"
2059 		 	"pmac_zilog: Did another serial driver already claim the minors?\n");
2060 		/* effectively "pmz_unprobe()" */
2061 		for (i=0; i < pmz_ports_count; i++)
2062 			pmz_dispose_port(&pmz_ports[i]);
2063 		return rc;
2064 	}
2065 
2066 	/*
2067 	 * Then we register the macio driver itself
2068 	 */
2069 #ifdef CONFIG_PPC_PMAC
2070 	return macio_register_driver(&pmz_driver);
2071 #else
2072 	return platform_driver_probe(&pmz_driver, pmz_attach);
2073 #endif
2074 }
2075 
2076 static void __exit exit_pmz(void)
2077 {
2078 	int i;
2079 
2080 #ifdef CONFIG_PPC_PMAC
2081 	/* Get rid of macio-driver (detach from macio) */
2082 	macio_unregister_driver(&pmz_driver);
2083 #else
2084 	platform_driver_unregister(&pmz_driver);
2085 #endif
2086 
2087 	for (i = 0; i < pmz_ports_count; i++) {
2088 		struct uart_pmac_port *uport = &pmz_ports[i];
2089 		if (uport->node != NULL) {
2090 			uart_remove_one_port(&pmz_uart_reg, &uport->port);
2091 			pmz_dispose_port(uport);
2092 		}
2093 	}
2094 	/* Unregister UART driver */
2095 	uart_unregister_driver(&pmz_uart_reg);
2096 }
2097 
2098 #ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
2099 
2100 static void pmz_console_putchar(struct uart_port *port, int ch)
2101 {
2102 	struct uart_pmac_port *uap = (struct uart_pmac_port *)port;
2103 
2104 	/* Wait for the transmit buffer to empty. */
2105 	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0)
2106 		udelay(5);
2107 	write_zsdata(uap, ch);
2108 }
2109 
2110 /*
2111  * Print a string to the serial port trying not to disturb
2112  * any possible real use of the port...
2113  */
2114 static void pmz_console_write(struct console *con, const char *s, unsigned int count)
2115 {
2116 	struct uart_pmac_port *uap = &pmz_ports[con->index];
2117 	unsigned long flags;
2118 
2119 	if (ZS_IS_ASLEEP(uap))
2120 		return;
2121 	spin_lock_irqsave(&uap->port.lock, flags);
2122 
2123 	/* Turn of interrupts and enable the transmitter. */
2124 	write_zsreg(uap, R1, uap->curregs[1] & ~TxINT_ENAB);
2125 	write_zsreg(uap, R5, uap->curregs[5] | TxENABLE | RTS | DTR);
2126 
2127 	uart_console_write(&uap->port, s, count, pmz_console_putchar);
2128 
2129 	/* Restore the values in the registers. */
2130 	write_zsreg(uap, R1, uap->curregs[1]);
2131 	/* Don't disable the transmitter. */
2132 
2133 	spin_unlock_irqrestore(&uap->port.lock, flags);
2134 }
2135 
2136 /*
2137  * Setup the serial console
2138  */
2139 static int __init pmz_console_setup(struct console *co, char *options)
2140 {
2141 	struct uart_pmac_port *uap;
2142 	struct uart_port *port;
2143 	int baud = 38400;
2144 	int bits = 8;
2145 	int parity = 'n';
2146 	int flow = 'n';
2147 	unsigned long pwr_delay;
2148 
2149 	/*
2150 	 * XServe's default to 57600 bps
2151 	 */
2152 	if (of_machine_is_compatible("RackMac1,1")
2153 	    || of_machine_is_compatible("RackMac1,2")
2154 	    || of_machine_is_compatible("MacRISC4"))
2155 		baud = 57600;
2156 
2157 	/*
2158 	 * Check whether an invalid uart number has been specified, and
2159 	 * if so, search for the first available port that does have
2160 	 * console support.
2161 	 */
2162 	if (co->index >= pmz_ports_count)
2163 		co->index = 0;
2164 	uap = &pmz_ports[co->index];
2165 	if (uap->node == NULL)
2166 		return -ENODEV;
2167 	port = &uap->port;
2168 
2169 	/*
2170 	 * Mark port as beeing a console
2171 	 */
2172 	uap->flags |= PMACZILOG_FLAG_IS_CONS;
2173 
2174 	/*
2175 	 * Temporary fix for uart layer who didn't setup the spinlock yet
2176 	 */
2177 	spin_lock_init(&port->lock);
2178 
2179 	/*
2180 	 * Enable the hardware
2181 	 */
2182 	pwr_delay = __pmz_startup(uap);
2183 	if (pwr_delay)
2184 		mdelay(pwr_delay);
2185 
2186 	if (options)
2187 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2188 
2189 	return uart_set_options(port, co, baud, parity, bits, flow);
2190 }
2191 
2192 static int __init pmz_console_init(void)
2193 {
2194 	/* Probe ports */
2195 	pmz_probe();
2196 
2197 	/* TODO: Autoprobe console based on OF */
2198 	/* pmz_console.index = i; */
2199 	register_console(&pmz_console);
2200 
2201 	return 0;
2202 
2203 }
2204 console_initcall(pmz_console_init);
2205 #endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
2206 
2207 module_init(init_pmz);
2208 module_exit(exit_pmz);
2209