xref: /openbmc/linux/drivers/tty/serial/pmac_zilog.c (revision e3b9f1e8)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Driver for PowerMac Z85c30 based ESCC cell found in the
4  * "macio" ASICs of various PowerMac models
5  *
6  * Copyright (C) 2003 Ben. Herrenschmidt (benh@kernel.crashing.org)
7  *
8  * Derived from drivers/macintosh/macserial.c by Paul Mackerras
9  * and drivers/serial/sunzilog.c by David S. Miller
10  *
11  * Hrm... actually, I ripped most of sunzilog (Thanks David !) and
12  * adapted special tweaks needed for us. I don't think it's worth
13  * merging back those though. The DMA code still has to get in
14  * and once done, I expect that driver to remain fairly stable in
15  * the long term, unless we change the driver model again...
16  *
17  * 2004-08-06 Harald Welte <laforge@gnumonks.org>
18  *	- Enable BREAK interrupt
19  *	- Add support for sysreq
20  *
21  * TODO:   - Add DMA support
22  *         - Defer port shutdown to a few seconds after close
23  *         - maybe put something right into uap->clk_divisor
24  */
25 
26 #undef DEBUG
27 #undef DEBUG_HARD
28 #undef USE_CTRL_O_SYSRQ
29 
30 #include <linux/module.h>
31 #include <linux/tty.h>
32 
33 #include <linux/tty_flip.h>
34 #include <linux/major.h>
35 #include <linux/string.h>
36 #include <linux/fcntl.h>
37 #include <linux/mm.h>
38 #include <linux/kernel.h>
39 #include <linux/delay.h>
40 #include <linux/init.h>
41 #include <linux/console.h>
42 #include <linux/adb.h>
43 #include <linux/pmu.h>
44 #include <linux/bitops.h>
45 #include <linux/sysrq.h>
46 #include <linux/mutex.h>
47 #include <linux/of_address.h>
48 #include <linux/of_irq.h>
49 #include <asm/sections.h>
50 #include <asm/io.h>
51 #include <asm/irq.h>
52 
53 #ifdef CONFIG_PPC_PMAC
54 #include <asm/prom.h>
55 #include <asm/machdep.h>
56 #include <asm/pmac_feature.h>
57 #include <asm/dbdma.h>
58 #include <asm/macio.h>
59 #else
60 #include <linux/platform_device.h>
61 #define of_machine_is_compatible(x) (0)
62 #endif
63 
64 #if defined (CONFIG_SERIAL_PMACZILOG_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
65 #define SUPPORT_SYSRQ
66 #endif
67 
68 #include <linux/serial.h>
69 #include <linux/serial_core.h>
70 
71 #include "pmac_zilog.h"
72 
73 /* Not yet implemented */
74 #undef HAS_DBDMA
75 
76 static char version[] __initdata = "pmac_zilog: 0.6 (Benjamin Herrenschmidt <benh@kernel.crashing.org>)";
77 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
78 MODULE_DESCRIPTION("Driver for the Mac and PowerMac serial ports.");
79 MODULE_LICENSE("GPL");
80 
81 #ifdef CONFIG_SERIAL_PMACZILOG_TTYS
82 #define PMACZILOG_MAJOR		TTY_MAJOR
83 #define PMACZILOG_MINOR		64
84 #define PMACZILOG_NAME		"ttyS"
85 #else
86 #define PMACZILOG_MAJOR		204
87 #define PMACZILOG_MINOR		192
88 #define PMACZILOG_NAME		"ttyPZ"
89 #endif
90 
91 #define pmz_debug(fmt, arg...)	pr_debug("ttyPZ%d: " fmt, uap->port.line, ## arg)
92 #define pmz_error(fmt, arg...)	pr_err("ttyPZ%d: " fmt, uap->port.line, ## arg)
93 #define pmz_info(fmt, arg...)	pr_info("ttyPZ%d: " fmt, uap->port.line, ## arg)
94 
95 /*
96  * For the sake of early serial console, we can do a pre-probe
97  * (optional) of the ports at rather early boot time.
98  */
99 static struct uart_pmac_port	pmz_ports[MAX_ZS_PORTS];
100 static int			pmz_ports_count;
101 
102 static struct uart_driver pmz_uart_reg = {
103 	.owner		=	THIS_MODULE,
104 	.driver_name	=	PMACZILOG_NAME,
105 	.dev_name	=	PMACZILOG_NAME,
106 	.major		=	PMACZILOG_MAJOR,
107 	.minor		=	PMACZILOG_MINOR,
108 };
109 
110 
111 /*
112  * Load all registers to reprogram the port
113  * This function must only be called when the TX is not busy.  The UART
114  * port lock must be held and local interrupts disabled.
115  */
116 static void pmz_load_zsregs(struct uart_pmac_port *uap, u8 *regs)
117 {
118 	int i;
119 
120 	/* Let pending transmits finish.  */
121 	for (i = 0; i < 1000; i++) {
122 		unsigned char stat = read_zsreg(uap, R1);
123 		if (stat & ALL_SNT)
124 			break;
125 		udelay(100);
126 	}
127 
128 	ZS_CLEARERR(uap);
129 	zssync(uap);
130 	ZS_CLEARFIFO(uap);
131 	zssync(uap);
132 	ZS_CLEARERR(uap);
133 
134 	/* Disable all interrupts.  */
135 	write_zsreg(uap, R1,
136 		    regs[R1] & ~(RxINT_MASK | TxINT_ENAB | EXT_INT_ENAB));
137 
138 	/* Set parity, sync config, stop bits, and clock divisor.  */
139 	write_zsreg(uap, R4, regs[R4]);
140 
141 	/* Set misc. TX/RX control bits.  */
142 	write_zsreg(uap, R10, regs[R10]);
143 
144 	/* Set TX/RX controls sans the enable bits.  */
145 	write_zsreg(uap, R3, regs[R3] & ~RxENABLE);
146 	write_zsreg(uap, R5, regs[R5] & ~TxENABLE);
147 
148 	/* now set R7 "prime" on ESCC */
149 	write_zsreg(uap, R15, regs[R15] | EN85C30);
150 	write_zsreg(uap, R7, regs[R7P]);
151 
152 	/* make sure we use R7 "non-prime" on ESCC */
153 	write_zsreg(uap, R15, regs[R15] & ~EN85C30);
154 
155 	/* Synchronous mode config.  */
156 	write_zsreg(uap, R6, regs[R6]);
157 	write_zsreg(uap, R7, regs[R7]);
158 
159 	/* Disable baud generator.  */
160 	write_zsreg(uap, R14, regs[R14] & ~BRENAB);
161 
162 	/* Clock mode control.  */
163 	write_zsreg(uap, R11, regs[R11]);
164 
165 	/* Lower and upper byte of baud rate generator divisor.  */
166 	write_zsreg(uap, R12, regs[R12]);
167 	write_zsreg(uap, R13, regs[R13]);
168 
169 	/* Now rewrite R14, with BRENAB (if set).  */
170 	write_zsreg(uap, R14, regs[R14]);
171 
172 	/* Reset external status interrupts.  */
173 	write_zsreg(uap, R0, RES_EXT_INT);
174 	write_zsreg(uap, R0, RES_EXT_INT);
175 
176 	/* Rewrite R3/R5, this time without enables masked.  */
177 	write_zsreg(uap, R3, regs[R3]);
178 	write_zsreg(uap, R5, regs[R5]);
179 
180 	/* Rewrite R1, this time without IRQ enabled masked.  */
181 	write_zsreg(uap, R1, regs[R1]);
182 
183 	/* Enable interrupts */
184 	write_zsreg(uap, R9, regs[R9]);
185 }
186 
187 /*
188  * We do like sunzilog to avoid disrupting pending Tx
189  * Reprogram the Zilog channel HW registers with the copies found in the
190  * software state struct.  If the transmitter is busy, we defer this update
191  * until the next TX complete interrupt.  Else, we do it right now.
192  *
193  * The UART port lock must be held and local interrupts disabled.
194  */
195 static void pmz_maybe_update_regs(struct uart_pmac_port *uap)
196 {
197 	if (!ZS_REGS_HELD(uap)) {
198 		if (ZS_TX_ACTIVE(uap)) {
199 			uap->flags |= PMACZILOG_FLAG_REGS_HELD;
200 		} else {
201 			pmz_debug("pmz: maybe_update_regs: updating\n");
202 			pmz_load_zsregs(uap, uap->curregs);
203 		}
204 	}
205 }
206 
207 static void pmz_interrupt_control(struct uart_pmac_port *uap, int enable)
208 {
209 	if (enable) {
210 		uap->curregs[1] |= INT_ALL_Rx | TxINT_ENAB;
211 		if (!ZS_IS_EXTCLK(uap))
212 			uap->curregs[1] |= EXT_INT_ENAB;
213 	} else {
214 		uap->curregs[1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
215 	}
216 	write_zsreg(uap, R1, uap->curregs[1]);
217 }
218 
219 static bool pmz_receive_chars(struct uart_pmac_port *uap)
220 {
221 	struct tty_port *port;
222 	unsigned char ch, r1, drop, error, flag;
223 	int loops = 0;
224 
225 	/* Sanity check, make sure the old bug is no longer happening */
226 	if (uap->port.state == NULL) {
227 		WARN_ON(1);
228 		(void)read_zsdata(uap);
229 		return false;
230 	}
231 	port = &uap->port.state->port;
232 
233 	while (1) {
234 		error = 0;
235 		drop = 0;
236 
237 		r1 = read_zsreg(uap, R1);
238 		ch = read_zsdata(uap);
239 
240 		if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR)) {
241 			write_zsreg(uap, R0, ERR_RES);
242 			zssync(uap);
243 		}
244 
245 		ch &= uap->parity_mask;
246 		if (ch == 0 && uap->flags & PMACZILOG_FLAG_BREAK) {
247 			uap->flags &= ~PMACZILOG_FLAG_BREAK;
248 		}
249 
250 #if defined(CONFIG_MAGIC_SYSRQ) && defined(CONFIG_SERIAL_CORE_CONSOLE)
251 #ifdef USE_CTRL_O_SYSRQ
252 		/* Handle the SysRq ^O Hack */
253 		if (ch == '\x0f') {
254 			uap->port.sysrq = jiffies + HZ*5;
255 			goto next_char;
256 		}
257 #endif /* USE_CTRL_O_SYSRQ */
258 		if (uap->port.sysrq) {
259 			int swallow;
260 			spin_unlock(&uap->port.lock);
261 			swallow = uart_handle_sysrq_char(&uap->port, ch);
262 			spin_lock(&uap->port.lock);
263 			if (swallow)
264 				goto next_char;
265 		}
266 #endif /* CONFIG_MAGIC_SYSRQ && CONFIG_SERIAL_CORE_CONSOLE */
267 
268 		/* A real serial line, record the character and status.  */
269 		if (drop)
270 			goto next_char;
271 
272 		flag = TTY_NORMAL;
273 		uap->port.icount.rx++;
274 
275 		if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR | BRK_ABRT)) {
276 			error = 1;
277 			if (r1 & BRK_ABRT) {
278 				pmz_debug("pmz: got break !\n");
279 				r1 &= ~(PAR_ERR | CRC_ERR);
280 				uap->port.icount.brk++;
281 				if (uart_handle_break(&uap->port))
282 					goto next_char;
283 			}
284 			else if (r1 & PAR_ERR)
285 				uap->port.icount.parity++;
286 			else if (r1 & CRC_ERR)
287 				uap->port.icount.frame++;
288 			if (r1 & Rx_OVR)
289 				uap->port.icount.overrun++;
290 			r1 &= uap->port.read_status_mask;
291 			if (r1 & BRK_ABRT)
292 				flag = TTY_BREAK;
293 			else if (r1 & PAR_ERR)
294 				flag = TTY_PARITY;
295 			else if (r1 & CRC_ERR)
296 				flag = TTY_FRAME;
297 		}
298 
299 		if (uap->port.ignore_status_mask == 0xff ||
300 		    (r1 & uap->port.ignore_status_mask) == 0) {
301 			tty_insert_flip_char(port, ch, flag);
302 		}
303 		if (r1 & Rx_OVR)
304 			tty_insert_flip_char(port, 0, TTY_OVERRUN);
305 	next_char:
306 		/* We can get stuck in an infinite loop getting char 0 when the
307 		 * line is in a wrong HW state, we break that here.
308 		 * When that happens, I disable the receive side of the driver.
309 		 * Note that what I've been experiencing is a real irq loop where
310 		 * I'm getting flooded regardless of the actual port speed.
311 		 * Something strange is going on with the HW
312 		 */
313 		if ((++loops) > 1000)
314 			goto flood;
315 		ch = read_zsreg(uap, R0);
316 		if (!(ch & Rx_CH_AV))
317 			break;
318 	}
319 
320 	return true;
321  flood:
322 	pmz_interrupt_control(uap, 0);
323 	pmz_error("pmz: rx irq flood !\n");
324 	return true;
325 }
326 
327 static void pmz_status_handle(struct uart_pmac_port *uap)
328 {
329 	unsigned char status;
330 
331 	status = read_zsreg(uap, R0);
332 	write_zsreg(uap, R0, RES_EXT_INT);
333 	zssync(uap);
334 
335 	if (ZS_IS_OPEN(uap) && ZS_WANTS_MODEM_STATUS(uap)) {
336 		if (status & SYNC_HUNT)
337 			uap->port.icount.dsr++;
338 
339 		/* The Zilog just gives us an interrupt when DCD/CTS/etc. change.
340 		 * But it does not tell us which bit has changed, we have to keep
341 		 * track of this ourselves.
342 		 * The CTS input is inverted for some reason.  -- paulus
343 		 */
344 		if ((status ^ uap->prev_status) & DCD)
345 			uart_handle_dcd_change(&uap->port,
346 					       (status & DCD));
347 		if ((status ^ uap->prev_status) & CTS)
348 			uart_handle_cts_change(&uap->port,
349 					       !(status & CTS));
350 
351 		wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
352 	}
353 
354 	if (status & BRK_ABRT)
355 		uap->flags |= PMACZILOG_FLAG_BREAK;
356 
357 	uap->prev_status = status;
358 }
359 
360 static void pmz_transmit_chars(struct uart_pmac_port *uap)
361 {
362 	struct circ_buf *xmit;
363 
364 	if (ZS_IS_CONS(uap)) {
365 		unsigned char status = read_zsreg(uap, R0);
366 
367 		/* TX still busy?  Just wait for the next TX done interrupt.
368 		 *
369 		 * It can occur because of how we do serial console writes.  It would
370 		 * be nice to transmit console writes just like we normally would for
371 		 * a TTY line. (ie. buffered and TX interrupt driven).  That is not
372 		 * easy because console writes cannot sleep.  One solution might be
373 		 * to poll on enough port->xmit space becoming free.  -DaveM
374 		 */
375 		if (!(status & Tx_BUF_EMP))
376 			return;
377 	}
378 
379 	uap->flags &= ~PMACZILOG_FLAG_TX_ACTIVE;
380 
381 	if (ZS_REGS_HELD(uap)) {
382 		pmz_load_zsregs(uap, uap->curregs);
383 		uap->flags &= ~PMACZILOG_FLAG_REGS_HELD;
384 	}
385 
386 	if (ZS_TX_STOPPED(uap)) {
387 		uap->flags &= ~PMACZILOG_FLAG_TX_STOPPED;
388 		goto ack_tx_int;
389 	}
390 
391 	/* Under some circumstances, we see interrupts reported for
392 	 * a closed channel. The interrupt mask in R1 is clear, but
393 	 * R3 still signals the interrupts and we see them when taking
394 	 * an interrupt for the other channel (this could be a qemu
395 	 * bug but since the ESCC doc doesn't specify precsiely whether
396 	 * R3 interrup status bits are masked by R1 interrupt enable
397 	 * bits, better safe than sorry). --BenH.
398 	 */
399 	if (!ZS_IS_OPEN(uap))
400 		goto ack_tx_int;
401 
402 	if (uap->port.x_char) {
403 		uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
404 		write_zsdata(uap, uap->port.x_char);
405 		zssync(uap);
406 		uap->port.icount.tx++;
407 		uap->port.x_char = 0;
408 		return;
409 	}
410 
411 	if (uap->port.state == NULL)
412 		goto ack_tx_int;
413 	xmit = &uap->port.state->xmit;
414 	if (uart_circ_empty(xmit)) {
415 		uart_write_wakeup(&uap->port);
416 		goto ack_tx_int;
417 	}
418 	if (uart_tx_stopped(&uap->port))
419 		goto ack_tx_int;
420 
421 	uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
422 	write_zsdata(uap, xmit->buf[xmit->tail]);
423 	zssync(uap);
424 
425 	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
426 	uap->port.icount.tx++;
427 
428 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
429 		uart_write_wakeup(&uap->port);
430 
431 	return;
432 
433 ack_tx_int:
434 	write_zsreg(uap, R0, RES_Tx_P);
435 	zssync(uap);
436 }
437 
438 /* Hrm... we register that twice, fixme later.... */
439 static irqreturn_t pmz_interrupt(int irq, void *dev_id)
440 {
441 	struct uart_pmac_port *uap = dev_id;
442 	struct uart_pmac_port *uap_a;
443 	struct uart_pmac_port *uap_b;
444 	int rc = IRQ_NONE;
445 	bool push;
446 	u8 r3;
447 
448 	uap_a = pmz_get_port_A(uap);
449 	uap_b = uap_a->mate;
450 
451 	spin_lock(&uap_a->port.lock);
452 	r3 = read_zsreg(uap_a, R3);
453 
454 #ifdef DEBUG_HARD
455 	pmz_debug("irq, r3: %x\n", r3);
456 #endif
457 	/* Channel A */
458 	push = false;
459 	if (r3 & (CHAEXT | CHATxIP | CHARxIP)) {
460 		if (!ZS_IS_OPEN(uap_a)) {
461 			pmz_debug("ChanA interrupt while not open !\n");
462 			goto skip_a;
463 		}
464 		write_zsreg(uap_a, R0, RES_H_IUS);
465 		zssync(uap_a);
466 		if (r3 & CHAEXT)
467 			pmz_status_handle(uap_a);
468 		if (r3 & CHARxIP)
469 			push = pmz_receive_chars(uap_a);
470 		if (r3 & CHATxIP)
471 			pmz_transmit_chars(uap_a);
472 		rc = IRQ_HANDLED;
473 	}
474  skip_a:
475 	spin_unlock(&uap_a->port.lock);
476 	if (push)
477 		tty_flip_buffer_push(&uap->port.state->port);
478 
479 	if (!uap_b)
480 		goto out;
481 
482 	spin_lock(&uap_b->port.lock);
483 	push = false;
484 	if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) {
485 		if (!ZS_IS_OPEN(uap_b)) {
486 			pmz_debug("ChanB interrupt while not open !\n");
487 			goto skip_b;
488 		}
489 		write_zsreg(uap_b, R0, RES_H_IUS);
490 		zssync(uap_b);
491 		if (r3 & CHBEXT)
492 			pmz_status_handle(uap_b);
493 		if (r3 & CHBRxIP)
494 			push = pmz_receive_chars(uap_b);
495 		if (r3 & CHBTxIP)
496 			pmz_transmit_chars(uap_b);
497 		rc = IRQ_HANDLED;
498 	}
499  skip_b:
500 	spin_unlock(&uap_b->port.lock);
501 	if (push)
502 		tty_flip_buffer_push(&uap->port.state->port);
503 
504  out:
505 	return rc;
506 }
507 
508 /*
509  * Peek the status register, lock not held by caller
510  */
511 static inline u8 pmz_peek_status(struct uart_pmac_port *uap)
512 {
513 	unsigned long flags;
514 	u8 status;
515 
516 	spin_lock_irqsave(&uap->port.lock, flags);
517 	status = read_zsreg(uap, R0);
518 	spin_unlock_irqrestore(&uap->port.lock, flags);
519 
520 	return status;
521 }
522 
523 /*
524  * Check if transmitter is empty
525  * The port lock is not held.
526  */
527 static unsigned int pmz_tx_empty(struct uart_port *port)
528 {
529 	unsigned char status;
530 
531 	status = pmz_peek_status(to_pmz(port));
532 	if (status & Tx_BUF_EMP)
533 		return TIOCSER_TEMT;
534 	return 0;
535 }
536 
537 /*
538  * Set Modem Control (RTS & DTR) bits
539  * The port lock is held and interrupts are disabled.
540  * Note: Shall we really filter out RTS on external ports or
541  * should that be dealt at higher level only ?
542  */
543 static void pmz_set_mctrl(struct uart_port *port, unsigned int mctrl)
544 {
545 	struct uart_pmac_port *uap = to_pmz(port);
546 	unsigned char set_bits, clear_bits;
547 
548         /* Do nothing for irda for now... */
549 	if (ZS_IS_IRDA(uap))
550 		return;
551 	/* We get called during boot with a port not up yet */
552 	if (!(ZS_IS_OPEN(uap) || ZS_IS_CONS(uap)))
553 		return;
554 
555 	set_bits = clear_bits = 0;
556 
557 	if (ZS_IS_INTMODEM(uap)) {
558 		if (mctrl & TIOCM_RTS)
559 			set_bits |= RTS;
560 		else
561 			clear_bits |= RTS;
562 	}
563 	if (mctrl & TIOCM_DTR)
564 		set_bits |= DTR;
565 	else
566 		clear_bits |= DTR;
567 
568 	/* NOTE: Not subject to 'transmitter active' rule.  */
569 	uap->curregs[R5] |= set_bits;
570 	uap->curregs[R5] &= ~clear_bits;
571 
572 	write_zsreg(uap, R5, uap->curregs[R5]);
573 	pmz_debug("pmz_set_mctrl: set bits: %x, clear bits: %x -> %x\n",
574 		  set_bits, clear_bits, uap->curregs[R5]);
575 	zssync(uap);
576 }
577 
578 /*
579  * Get Modem Control bits (only the input ones, the core will
580  * or that with a cached value of the control ones)
581  * The port lock is held and interrupts are disabled.
582  */
583 static unsigned int pmz_get_mctrl(struct uart_port *port)
584 {
585 	struct uart_pmac_port *uap = to_pmz(port);
586 	unsigned char status;
587 	unsigned int ret;
588 
589 	status = read_zsreg(uap, R0);
590 
591 	ret = 0;
592 	if (status & DCD)
593 		ret |= TIOCM_CAR;
594 	if (status & SYNC_HUNT)
595 		ret |= TIOCM_DSR;
596 	if (!(status & CTS))
597 		ret |= TIOCM_CTS;
598 
599 	return ret;
600 }
601 
602 /*
603  * Stop TX side. Dealt like sunzilog at next Tx interrupt,
604  * though for DMA, we will have to do a bit more.
605  * The port lock is held and interrupts are disabled.
606  */
607 static void pmz_stop_tx(struct uart_port *port)
608 {
609 	to_pmz(port)->flags |= PMACZILOG_FLAG_TX_STOPPED;
610 }
611 
612 /*
613  * Kick the Tx side.
614  * The port lock is held and interrupts are disabled.
615  */
616 static void pmz_start_tx(struct uart_port *port)
617 {
618 	struct uart_pmac_port *uap = to_pmz(port);
619 	unsigned char status;
620 
621 	pmz_debug("pmz: start_tx()\n");
622 
623 	uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
624 	uap->flags &= ~PMACZILOG_FLAG_TX_STOPPED;
625 
626 	status = read_zsreg(uap, R0);
627 
628 	/* TX busy?  Just wait for the TX done interrupt.  */
629 	if (!(status & Tx_BUF_EMP))
630 		return;
631 
632 	/* Send the first character to jump-start the TX done
633 	 * IRQ sending engine.
634 	 */
635 	if (port->x_char) {
636 		write_zsdata(uap, port->x_char);
637 		zssync(uap);
638 		port->icount.tx++;
639 		port->x_char = 0;
640 	} else {
641 		struct circ_buf *xmit = &port->state->xmit;
642 
643 		if (uart_circ_empty(xmit))
644 			goto out;
645 		write_zsdata(uap, xmit->buf[xmit->tail]);
646 		zssync(uap);
647 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
648 		port->icount.tx++;
649 
650 		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
651 			uart_write_wakeup(&uap->port);
652 	}
653  out:
654 	pmz_debug("pmz: start_tx() done.\n");
655 }
656 
657 /*
658  * Stop Rx side, basically disable emitting of
659  * Rx interrupts on the port. We don't disable the rx
660  * side of the chip proper though
661  * The port lock is held.
662  */
663 static void pmz_stop_rx(struct uart_port *port)
664 {
665 	struct uart_pmac_port *uap = to_pmz(port);
666 
667 	pmz_debug("pmz: stop_rx()()\n");
668 
669 	/* Disable all RX interrupts.  */
670 	uap->curregs[R1] &= ~RxINT_MASK;
671 	pmz_maybe_update_regs(uap);
672 
673 	pmz_debug("pmz: stop_rx() done.\n");
674 }
675 
676 /*
677  * Enable modem status change interrupts
678  * The port lock is held.
679  */
680 static void pmz_enable_ms(struct uart_port *port)
681 {
682 	struct uart_pmac_port *uap = to_pmz(port);
683 	unsigned char new_reg;
684 
685 	if (ZS_IS_IRDA(uap))
686 		return;
687 	new_reg = uap->curregs[R15] | (DCDIE | SYNCIE | CTSIE);
688 	if (new_reg != uap->curregs[R15]) {
689 		uap->curregs[R15] = new_reg;
690 
691 		/* NOTE: Not subject to 'transmitter active' rule. */
692 		write_zsreg(uap, R15, uap->curregs[R15]);
693 	}
694 }
695 
696 /*
697  * Control break state emission
698  * The port lock is not held.
699  */
700 static void pmz_break_ctl(struct uart_port *port, int break_state)
701 {
702 	struct uart_pmac_port *uap = to_pmz(port);
703 	unsigned char set_bits, clear_bits, new_reg;
704 	unsigned long flags;
705 
706 	set_bits = clear_bits = 0;
707 
708 	if (break_state)
709 		set_bits |= SND_BRK;
710 	else
711 		clear_bits |= SND_BRK;
712 
713 	spin_lock_irqsave(&port->lock, flags);
714 
715 	new_reg = (uap->curregs[R5] | set_bits) & ~clear_bits;
716 	if (new_reg != uap->curregs[R5]) {
717 		uap->curregs[R5] = new_reg;
718 		write_zsreg(uap, R5, uap->curregs[R5]);
719 	}
720 
721 	spin_unlock_irqrestore(&port->lock, flags);
722 }
723 
724 #ifdef CONFIG_PPC_PMAC
725 
726 /*
727  * Turn power on or off to the SCC and associated stuff
728  * (port drivers, modem, IR port, etc.)
729  * Returns the number of milliseconds we should wait before
730  * trying to use the port.
731  */
732 static int pmz_set_scc_power(struct uart_pmac_port *uap, int state)
733 {
734 	int delay = 0;
735 	int rc;
736 
737 	if (state) {
738 		rc = pmac_call_feature(
739 			PMAC_FTR_SCC_ENABLE, uap->node, uap->port_type, 1);
740 		pmz_debug("port power on result: %d\n", rc);
741 		if (ZS_IS_INTMODEM(uap)) {
742 			rc = pmac_call_feature(
743 				PMAC_FTR_MODEM_ENABLE, uap->node, 0, 1);
744 			delay = 2500;	/* wait for 2.5s before using */
745 			pmz_debug("modem power result: %d\n", rc);
746 		}
747 	} else {
748 		/* TODO: Make that depend on a timer, don't power down
749 		 * immediately
750 		 */
751 		if (ZS_IS_INTMODEM(uap)) {
752 			rc = pmac_call_feature(
753 				PMAC_FTR_MODEM_ENABLE, uap->node, 0, 0);
754 			pmz_debug("port power off result: %d\n", rc);
755 		}
756 		pmac_call_feature(PMAC_FTR_SCC_ENABLE, uap->node, uap->port_type, 0);
757 	}
758 	return delay;
759 }
760 
761 #else
762 
763 static int pmz_set_scc_power(struct uart_pmac_port *uap, int state)
764 {
765 	return 0;
766 }
767 
768 #endif /* !CONFIG_PPC_PMAC */
769 
770 /*
771  * FixZeroBug....Works around a bug in the SCC receiving channel.
772  * Inspired from Darwin code, 15 Sept. 2000  -DanM
773  *
774  * The following sequence prevents a problem that is seen with O'Hare ASICs
775  * (most versions -- also with some Heathrow and Hydra ASICs) where a zero
776  * at the input to the receiver becomes 'stuck' and locks up the receiver.
777  * This problem can occur as a result of a zero bit at the receiver input
778  * coincident with any of the following events:
779  *
780  *	The SCC is initialized (hardware or software).
781  *	A framing error is detected.
782  *	The clocking option changes from synchronous or X1 asynchronous
783  *		clocking to X16, X32, or X64 asynchronous clocking.
784  *	The decoding mode is changed among NRZ, NRZI, FM0, or FM1.
785  *
786  * This workaround attempts to recover from the lockup condition by placing
787  * the SCC in synchronous loopback mode with a fast clock before programming
788  * any of the asynchronous modes.
789  */
790 static void pmz_fix_zero_bug_scc(struct uart_pmac_port *uap)
791 {
792 	write_zsreg(uap, 9, ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB);
793 	zssync(uap);
794 	udelay(10);
795 	write_zsreg(uap, 9, (ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB) | NV);
796 	zssync(uap);
797 
798 	write_zsreg(uap, 4, X1CLK | MONSYNC);
799 	write_zsreg(uap, 3, Rx8);
800 	write_zsreg(uap, 5, Tx8 | RTS);
801 	write_zsreg(uap, 9, NV);	/* Didn't we already do this? */
802 	write_zsreg(uap, 11, RCBR | TCBR);
803 	write_zsreg(uap, 12, 0);
804 	write_zsreg(uap, 13, 0);
805 	write_zsreg(uap, 14, (LOOPBAK | BRSRC));
806 	write_zsreg(uap, 14, (LOOPBAK | BRSRC | BRENAB));
807 	write_zsreg(uap, 3, Rx8 | RxENABLE);
808 	write_zsreg(uap, 0, RES_EXT_INT);
809 	write_zsreg(uap, 0, RES_EXT_INT);
810 	write_zsreg(uap, 0, RES_EXT_INT);	/* to kill some time */
811 
812 	/* The channel should be OK now, but it is probably receiving
813 	 * loopback garbage.
814 	 * Switch to asynchronous mode, disable the receiver,
815 	 * and discard everything in the receive buffer.
816 	 */
817 	write_zsreg(uap, 9, NV);
818 	write_zsreg(uap, 4, X16CLK | SB_MASK);
819 	write_zsreg(uap, 3, Rx8);
820 
821 	while (read_zsreg(uap, 0) & Rx_CH_AV) {
822 		(void)read_zsreg(uap, 8);
823 		write_zsreg(uap, 0, RES_EXT_INT);
824 		write_zsreg(uap, 0, ERR_RES);
825 	}
826 }
827 
828 /*
829  * Real startup routine, powers up the hardware and sets up
830  * the SCC. Returns a delay in ms where you need to wait before
831  * actually using the port, this is typically the internal modem
832  * powerup delay. This routine expect the lock to be taken.
833  */
834 static int __pmz_startup(struct uart_pmac_port *uap)
835 {
836 	int pwr_delay = 0;
837 
838 	memset(&uap->curregs, 0, sizeof(uap->curregs));
839 
840 	/* Power up the SCC & underlying hardware (modem/irda) */
841 	pwr_delay = pmz_set_scc_power(uap, 1);
842 
843 	/* Nice buggy HW ... */
844 	pmz_fix_zero_bug_scc(uap);
845 
846 	/* Reset the channel */
847 	uap->curregs[R9] = 0;
848 	write_zsreg(uap, 9, ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB);
849 	zssync(uap);
850 	udelay(10);
851 	write_zsreg(uap, 9, 0);
852 	zssync(uap);
853 
854 	/* Clear the interrupt registers */
855 	write_zsreg(uap, R1, 0);
856 	write_zsreg(uap, R0, ERR_RES);
857 	write_zsreg(uap, R0, ERR_RES);
858 	write_zsreg(uap, R0, RES_H_IUS);
859 	write_zsreg(uap, R0, RES_H_IUS);
860 
861 	/* Setup some valid baud rate */
862 	uap->curregs[R4] = X16CLK | SB1;
863 	uap->curregs[R3] = Rx8;
864 	uap->curregs[R5] = Tx8 | RTS;
865 	if (!ZS_IS_IRDA(uap))
866 		uap->curregs[R5] |= DTR;
867 	uap->curregs[R12] = 0;
868 	uap->curregs[R13] = 0;
869 	uap->curregs[R14] = BRENAB;
870 
871 	/* Clear handshaking, enable BREAK interrupts */
872 	uap->curregs[R15] = BRKIE;
873 
874 	/* Master interrupt enable */
875 	uap->curregs[R9] |= NV | MIE;
876 
877 	pmz_load_zsregs(uap, uap->curregs);
878 
879 	/* Enable receiver and transmitter.  */
880 	write_zsreg(uap, R3, uap->curregs[R3] |= RxENABLE);
881 	write_zsreg(uap, R5, uap->curregs[R5] |= TxENABLE);
882 
883 	/* Remember status for DCD/CTS changes */
884 	uap->prev_status = read_zsreg(uap, R0);
885 
886 	return pwr_delay;
887 }
888 
889 static void pmz_irda_reset(struct uart_pmac_port *uap)
890 {
891 	unsigned long flags;
892 
893 	spin_lock_irqsave(&uap->port.lock, flags);
894 	uap->curregs[R5] |= DTR;
895 	write_zsreg(uap, R5, uap->curregs[R5]);
896 	zssync(uap);
897 	spin_unlock_irqrestore(&uap->port.lock, flags);
898 	msleep(110);
899 
900 	spin_lock_irqsave(&uap->port.lock, flags);
901 	uap->curregs[R5] &= ~DTR;
902 	write_zsreg(uap, R5, uap->curregs[R5]);
903 	zssync(uap);
904 	spin_unlock_irqrestore(&uap->port.lock, flags);
905 	msleep(10);
906 }
907 
908 /*
909  * This is the "normal" startup routine, using the above one
910  * wrapped with the lock and doing a schedule delay
911  */
912 static int pmz_startup(struct uart_port *port)
913 {
914 	struct uart_pmac_port *uap = to_pmz(port);
915 	unsigned long flags;
916 	int pwr_delay = 0;
917 
918 	pmz_debug("pmz: startup()\n");
919 
920 	uap->flags |= PMACZILOG_FLAG_IS_OPEN;
921 
922 	/* A console is never powered down. Else, power up and
923 	 * initialize the chip
924 	 */
925 	if (!ZS_IS_CONS(uap)) {
926 		spin_lock_irqsave(&port->lock, flags);
927 		pwr_delay = __pmz_startup(uap);
928 		spin_unlock_irqrestore(&port->lock, flags);
929 	}
930 	sprintf(uap->irq_name, PMACZILOG_NAME"%d", uap->port.line);
931 	if (request_irq(uap->port.irq, pmz_interrupt, IRQF_SHARED,
932 			uap->irq_name, uap)) {
933 		pmz_error("Unable to register zs interrupt handler.\n");
934 		pmz_set_scc_power(uap, 0);
935 		return -ENXIO;
936 	}
937 
938 	/* Right now, we deal with delay by blocking here, I'll be
939 	 * smarter later on
940 	 */
941 	if (pwr_delay != 0) {
942 		pmz_debug("pmz: delaying %d ms\n", pwr_delay);
943 		msleep(pwr_delay);
944 	}
945 
946 	/* IrDA reset is done now */
947 	if (ZS_IS_IRDA(uap))
948 		pmz_irda_reset(uap);
949 
950 	/* Enable interrupt requests for the channel */
951 	spin_lock_irqsave(&port->lock, flags);
952 	pmz_interrupt_control(uap, 1);
953 	spin_unlock_irqrestore(&port->lock, flags);
954 
955 	pmz_debug("pmz: startup() done.\n");
956 
957 	return 0;
958 }
959 
960 static void pmz_shutdown(struct uart_port *port)
961 {
962 	struct uart_pmac_port *uap = to_pmz(port);
963 	unsigned long flags;
964 
965 	pmz_debug("pmz: shutdown()\n");
966 
967 	spin_lock_irqsave(&port->lock, flags);
968 
969 	/* Disable interrupt requests for the channel */
970 	pmz_interrupt_control(uap, 0);
971 
972 	if (!ZS_IS_CONS(uap)) {
973 		/* Disable receiver and transmitter */
974 		uap->curregs[R3] &= ~RxENABLE;
975 		uap->curregs[R5] &= ~TxENABLE;
976 
977 		/* Disable break assertion */
978 		uap->curregs[R5] &= ~SND_BRK;
979 		pmz_maybe_update_regs(uap);
980 	}
981 
982 	spin_unlock_irqrestore(&port->lock, flags);
983 
984 	/* Release interrupt handler */
985 	free_irq(uap->port.irq, uap);
986 
987 	spin_lock_irqsave(&port->lock, flags);
988 
989 	uap->flags &= ~PMACZILOG_FLAG_IS_OPEN;
990 
991 	if (!ZS_IS_CONS(uap))
992 		pmz_set_scc_power(uap, 0);	/* Shut the chip down */
993 
994 	spin_unlock_irqrestore(&port->lock, flags);
995 
996 	pmz_debug("pmz: shutdown() done.\n");
997 }
998 
999 /* Shared by TTY driver and serial console setup.  The port lock is held
1000  * and local interrupts are disabled.
1001  */
1002 static void pmz_convert_to_zs(struct uart_pmac_port *uap, unsigned int cflag,
1003 			      unsigned int iflag, unsigned long baud)
1004 {
1005 	int brg;
1006 
1007 	/* Switch to external clocking for IrDA high clock rates. That
1008 	 * code could be re-used for Midi interfaces with different
1009 	 * multipliers
1010 	 */
1011 	if (baud >= 115200 && ZS_IS_IRDA(uap)) {
1012 		uap->curregs[R4] = X1CLK;
1013 		uap->curregs[R11] = RCTRxCP | TCTRxCP;
1014 		uap->curregs[R14] = 0; /* BRG off */
1015 		uap->curregs[R12] = 0;
1016 		uap->curregs[R13] = 0;
1017 		uap->flags |= PMACZILOG_FLAG_IS_EXTCLK;
1018 	} else {
1019 		switch (baud) {
1020 		case ZS_CLOCK/16:	/* 230400 */
1021 			uap->curregs[R4] = X16CLK;
1022 			uap->curregs[R11] = 0;
1023 			uap->curregs[R14] = 0;
1024 			break;
1025 		case ZS_CLOCK/32:	/* 115200 */
1026 			uap->curregs[R4] = X32CLK;
1027 			uap->curregs[R11] = 0;
1028 			uap->curregs[R14] = 0;
1029 			break;
1030 		default:
1031 			uap->curregs[R4] = X16CLK;
1032 			uap->curregs[R11] = TCBR | RCBR;
1033 			brg = BPS_TO_BRG(baud, ZS_CLOCK / 16);
1034 			uap->curregs[R12] = (brg & 255);
1035 			uap->curregs[R13] = ((brg >> 8) & 255);
1036 			uap->curregs[R14] = BRENAB;
1037 		}
1038 		uap->flags &= ~PMACZILOG_FLAG_IS_EXTCLK;
1039 	}
1040 
1041 	/* Character size, stop bits, and parity. */
1042 	uap->curregs[3] &= ~RxN_MASK;
1043 	uap->curregs[5] &= ~TxN_MASK;
1044 
1045 	switch (cflag & CSIZE) {
1046 	case CS5:
1047 		uap->curregs[3] |= Rx5;
1048 		uap->curregs[5] |= Tx5;
1049 		uap->parity_mask = 0x1f;
1050 		break;
1051 	case CS6:
1052 		uap->curregs[3] |= Rx6;
1053 		uap->curregs[5] |= Tx6;
1054 		uap->parity_mask = 0x3f;
1055 		break;
1056 	case CS7:
1057 		uap->curregs[3] |= Rx7;
1058 		uap->curregs[5] |= Tx7;
1059 		uap->parity_mask = 0x7f;
1060 		break;
1061 	case CS8:
1062 	default:
1063 		uap->curregs[3] |= Rx8;
1064 		uap->curregs[5] |= Tx8;
1065 		uap->parity_mask = 0xff;
1066 		break;
1067 	}
1068 	uap->curregs[4] &= ~(SB_MASK);
1069 	if (cflag & CSTOPB)
1070 		uap->curregs[4] |= SB2;
1071 	else
1072 		uap->curregs[4] |= SB1;
1073 	if (cflag & PARENB)
1074 		uap->curregs[4] |= PAR_ENAB;
1075 	else
1076 		uap->curregs[4] &= ~PAR_ENAB;
1077 	if (!(cflag & PARODD))
1078 		uap->curregs[4] |= PAR_EVEN;
1079 	else
1080 		uap->curregs[4] &= ~PAR_EVEN;
1081 
1082 	uap->port.read_status_mask = Rx_OVR;
1083 	if (iflag & INPCK)
1084 		uap->port.read_status_mask |= CRC_ERR | PAR_ERR;
1085 	if (iflag & (IGNBRK | BRKINT | PARMRK))
1086 		uap->port.read_status_mask |= BRK_ABRT;
1087 
1088 	uap->port.ignore_status_mask = 0;
1089 	if (iflag & IGNPAR)
1090 		uap->port.ignore_status_mask |= CRC_ERR | PAR_ERR;
1091 	if (iflag & IGNBRK) {
1092 		uap->port.ignore_status_mask |= BRK_ABRT;
1093 		if (iflag & IGNPAR)
1094 			uap->port.ignore_status_mask |= Rx_OVR;
1095 	}
1096 
1097 	if ((cflag & CREAD) == 0)
1098 		uap->port.ignore_status_mask = 0xff;
1099 }
1100 
1101 
1102 /*
1103  * Set the irda codec on the imac to the specified baud rate.
1104  */
1105 static void pmz_irda_setup(struct uart_pmac_port *uap, unsigned long *baud)
1106 {
1107 	u8 cmdbyte;
1108 	int t, version;
1109 
1110 	switch (*baud) {
1111 	/* SIR modes */
1112 	case 2400:
1113 		cmdbyte = 0x53;
1114 		break;
1115 	case 4800:
1116 		cmdbyte = 0x52;
1117 		break;
1118 	case 9600:
1119 		cmdbyte = 0x51;
1120 		break;
1121 	case 19200:
1122 		cmdbyte = 0x50;
1123 		break;
1124 	case 38400:
1125 		cmdbyte = 0x4f;
1126 		break;
1127 	case 57600:
1128 		cmdbyte = 0x4e;
1129 		break;
1130 	case 115200:
1131 		cmdbyte = 0x4d;
1132 		break;
1133 	/* The FIR modes aren't really supported at this point, how
1134 	 * do we select the speed ? via the FCR on KeyLargo ?
1135 	 */
1136 	case 1152000:
1137 		cmdbyte = 0;
1138 		break;
1139 	case 4000000:
1140 		cmdbyte = 0;
1141 		break;
1142 	default: /* 9600 */
1143 		cmdbyte = 0x51;
1144 		*baud = 9600;
1145 		break;
1146 	}
1147 
1148 	/* Wait for transmitter to drain */
1149 	t = 10000;
1150 	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0
1151 	       || (read_zsreg(uap, R1) & ALL_SNT) == 0) {
1152 		if (--t <= 0) {
1153 			pmz_error("transmitter didn't drain\n");
1154 			return;
1155 		}
1156 		udelay(10);
1157 	}
1158 
1159 	/* Drain the receiver too */
1160 	t = 100;
1161 	(void)read_zsdata(uap);
1162 	(void)read_zsdata(uap);
1163 	(void)read_zsdata(uap);
1164 	mdelay(10);
1165 	while (read_zsreg(uap, R0) & Rx_CH_AV) {
1166 		read_zsdata(uap);
1167 		mdelay(10);
1168 		if (--t <= 0) {
1169 			pmz_error("receiver didn't drain\n");
1170 			return;
1171 		}
1172 	}
1173 
1174 	/* Switch to command mode */
1175 	uap->curregs[R5] |= DTR;
1176 	write_zsreg(uap, R5, uap->curregs[R5]);
1177 	zssync(uap);
1178 	mdelay(1);
1179 
1180 	/* Switch SCC to 19200 */
1181 	pmz_convert_to_zs(uap, CS8, 0, 19200);
1182 	pmz_load_zsregs(uap, uap->curregs);
1183 	mdelay(1);
1184 
1185 	/* Write get_version command byte */
1186 	write_zsdata(uap, 1);
1187 	t = 5000;
1188 	while ((read_zsreg(uap, R0) & Rx_CH_AV) == 0) {
1189 		if (--t <= 0) {
1190 			pmz_error("irda_setup timed out on get_version byte\n");
1191 			goto out;
1192 		}
1193 		udelay(10);
1194 	}
1195 	version = read_zsdata(uap);
1196 
1197 	if (version < 4) {
1198 		pmz_info("IrDA: dongle version %d not supported\n", version);
1199 		goto out;
1200 	}
1201 
1202 	/* Send speed mode */
1203 	write_zsdata(uap, cmdbyte);
1204 	t = 5000;
1205 	while ((read_zsreg(uap, R0) & Rx_CH_AV) == 0) {
1206 		if (--t <= 0) {
1207 			pmz_error("irda_setup timed out on speed mode byte\n");
1208 			goto out;
1209 		}
1210 		udelay(10);
1211 	}
1212 	t = read_zsdata(uap);
1213 	if (t != cmdbyte)
1214 		pmz_error("irda_setup speed mode byte = %x (%x)\n", t, cmdbyte);
1215 
1216 	pmz_info("IrDA setup for %ld bps, dongle version: %d\n",
1217 		 *baud, version);
1218 
1219 	(void)read_zsdata(uap);
1220 	(void)read_zsdata(uap);
1221 	(void)read_zsdata(uap);
1222 
1223  out:
1224 	/* Switch back to data mode */
1225 	uap->curregs[R5] &= ~DTR;
1226 	write_zsreg(uap, R5, uap->curregs[R5]);
1227 	zssync(uap);
1228 
1229 	(void)read_zsdata(uap);
1230 	(void)read_zsdata(uap);
1231 	(void)read_zsdata(uap);
1232 }
1233 
1234 
1235 static void __pmz_set_termios(struct uart_port *port, struct ktermios *termios,
1236 			      struct ktermios *old)
1237 {
1238 	struct uart_pmac_port *uap = to_pmz(port);
1239 	unsigned long baud;
1240 
1241 	pmz_debug("pmz: set_termios()\n");
1242 
1243 	memcpy(&uap->termios_cache, termios, sizeof(struct ktermios));
1244 
1245 	/* XXX Check which revs of machines actually allow 1 and 4Mb speeds
1246 	 * on the IR dongle. Note that the IRTTY driver currently doesn't know
1247 	 * about the FIR mode and high speed modes. So these are unused. For
1248 	 * implementing proper support for these, we should probably add some
1249 	 * DMA as well, at least on the Rx side, which isn't a simple thing
1250 	 * at this point.
1251 	 */
1252 	if (ZS_IS_IRDA(uap)) {
1253 		/* Calc baud rate */
1254 		baud = uart_get_baud_rate(port, termios, old, 1200, 4000000);
1255 		pmz_debug("pmz: switch IRDA to %ld bauds\n", baud);
1256 		/* Cet the irda codec to the right rate */
1257 		pmz_irda_setup(uap, &baud);
1258 		/* Set final baud rate */
1259 		pmz_convert_to_zs(uap, termios->c_cflag, termios->c_iflag, baud);
1260 		pmz_load_zsregs(uap, uap->curregs);
1261 		zssync(uap);
1262 	} else {
1263 		baud = uart_get_baud_rate(port, termios, old, 1200, 230400);
1264 		pmz_convert_to_zs(uap, termios->c_cflag, termios->c_iflag, baud);
1265 		/* Make sure modem status interrupts are correctly configured */
1266 		if (UART_ENABLE_MS(&uap->port, termios->c_cflag)) {
1267 			uap->curregs[R15] |= DCDIE | SYNCIE | CTSIE;
1268 			uap->flags |= PMACZILOG_FLAG_MODEM_STATUS;
1269 		} else {
1270 			uap->curregs[R15] &= ~(DCDIE | SYNCIE | CTSIE);
1271 			uap->flags &= ~PMACZILOG_FLAG_MODEM_STATUS;
1272 		}
1273 
1274 		/* Load registers to the chip */
1275 		pmz_maybe_update_regs(uap);
1276 	}
1277 	uart_update_timeout(port, termios->c_cflag, baud);
1278 
1279 	pmz_debug("pmz: set_termios() done.\n");
1280 }
1281 
1282 /* The port lock is not held.  */
1283 static void pmz_set_termios(struct uart_port *port, struct ktermios *termios,
1284 			    struct ktermios *old)
1285 {
1286 	struct uart_pmac_port *uap = to_pmz(port);
1287 	unsigned long flags;
1288 
1289 	spin_lock_irqsave(&port->lock, flags);
1290 
1291 	/* Disable IRQs on the port */
1292 	pmz_interrupt_control(uap, 0);
1293 
1294 	/* Setup new port configuration */
1295 	__pmz_set_termios(port, termios, old);
1296 
1297 	/* Re-enable IRQs on the port */
1298 	if (ZS_IS_OPEN(uap))
1299 		pmz_interrupt_control(uap, 1);
1300 
1301 	spin_unlock_irqrestore(&port->lock, flags);
1302 }
1303 
1304 static const char *pmz_type(struct uart_port *port)
1305 {
1306 	struct uart_pmac_port *uap = to_pmz(port);
1307 
1308 	if (ZS_IS_IRDA(uap))
1309 		return "Z85c30 ESCC - Infrared port";
1310 	else if (ZS_IS_INTMODEM(uap))
1311 		return "Z85c30 ESCC - Internal modem";
1312 	return "Z85c30 ESCC - Serial port";
1313 }
1314 
1315 /* We do not request/release mappings of the registers here, this
1316  * happens at early serial probe time.
1317  */
1318 static void pmz_release_port(struct uart_port *port)
1319 {
1320 }
1321 
1322 static int pmz_request_port(struct uart_port *port)
1323 {
1324 	return 0;
1325 }
1326 
1327 /* These do not need to do anything interesting either.  */
1328 static void pmz_config_port(struct uart_port *port, int flags)
1329 {
1330 }
1331 
1332 /* We do not support letting the user mess with the divisor, IRQ, etc. */
1333 static int pmz_verify_port(struct uart_port *port, struct serial_struct *ser)
1334 {
1335 	return -EINVAL;
1336 }
1337 
1338 #ifdef CONFIG_CONSOLE_POLL
1339 
1340 static int pmz_poll_get_char(struct uart_port *port)
1341 {
1342 	struct uart_pmac_port *uap =
1343 		container_of(port, struct uart_pmac_port, port);
1344 	int tries = 2;
1345 
1346 	while (tries) {
1347 		if ((read_zsreg(uap, R0) & Rx_CH_AV) != 0)
1348 			return read_zsdata(uap);
1349 		if (tries--)
1350 			udelay(5);
1351 	}
1352 
1353 	return NO_POLL_CHAR;
1354 }
1355 
1356 static void pmz_poll_put_char(struct uart_port *port, unsigned char c)
1357 {
1358 	struct uart_pmac_port *uap =
1359 		container_of(port, struct uart_pmac_port, port);
1360 
1361 	/* Wait for the transmit buffer to empty. */
1362 	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0)
1363 		udelay(5);
1364 	write_zsdata(uap, c);
1365 }
1366 
1367 #endif /* CONFIG_CONSOLE_POLL */
1368 
1369 static const struct uart_ops pmz_pops = {
1370 	.tx_empty	=	pmz_tx_empty,
1371 	.set_mctrl	=	pmz_set_mctrl,
1372 	.get_mctrl	=	pmz_get_mctrl,
1373 	.stop_tx	=	pmz_stop_tx,
1374 	.start_tx	=	pmz_start_tx,
1375 	.stop_rx	=	pmz_stop_rx,
1376 	.enable_ms	=	pmz_enable_ms,
1377 	.break_ctl	=	pmz_break_ctl,
1378 	.startup	=	pmz_startup,
1379 	.shutdown	=	pmz_shutdown,
1380 	.set_termios	=	pmz_set_termios,
1381 	.type		=	pmz_type,
1382 	.release_port	=	pmz_release_port,
1383 	.request_port	=	pmz_request_port,
1384 	.config_port	=	pmz_config_port,
1385 	.verify_port	=	pmz_verify_port,
1386 #ifdef CONFIG_CONSOLE_POLL
1387 	.poll_get_char	=	pmz_poll_get_char,
1388 	.poll_put_char	=	pmz_poll_put_char,
1389 #endif
1390 };
1391 
1392 #ifdef CONFIG_PPC_PMAC
1393 
1394 /*
1395  * Setup one port structure after probing, HW is down at this point,
1396  * Unlike sunzilog, we don't need to pre-init the spinlock as we don't
1397  * register our console before uart_add_one_port() is called
1398  */
1399 static int __init pmz_init_port(struct uart_pmac_port *uap)
1400 {
1401 	struct device_node *np = uap->node;
1402 	const char *conn;
1403 	const struct slot_names_prop {
1404 		int	count;
1405 		char	name[1];
1406 	} *slots;
1407 	int len;
1408 	struct resource r_ports, r_rxdma, r_txdma;
1409 
1410 	/*
1411 	 * Request & map chip registers
1412 	 */
1413 	if (of_address_to_resource(np, 0, &r_ports))
1414 		return -ENODEV;
1415 	uap->port.mapbase = r_ports.start;
1416 	uap->port.membase = ioremap(uap->port.mapbase, 0x1000);
1417 
1418 	uap->control_reg = uap->port.membase;
1419 	uap->data_reg = uap->control_reg + 0x10;
1420 
1421 	/*
1422 	 * Request & map DBDMA registers
1423 	 */
1424 #ifdef HAS_DBDMA
1425 	if (of_address_to_resource(np, 1, &r_txdma) == 0 &&
1426 	    of_address_to_resource(np, 2, &r_rxdma) == 0)
1427 		uap->flags |= PMACZILOG_FLAG_HAS_DMA;
1428 #else
1429 	memset(&r_txdma, 0, sizeof(struct resource));
1430 	memset(&r_rxdma, 0, sizeof(struct resource));
1431 #endif
1432 	if (ZS_HAS_DMA(uap)) {
1433 		uap->tx_dma_regs = ioremap(r_txdma.start, 0x100);
1434 		if (uap->tx_dma_regs == NULL) {
1435 			uap->flags &= ~PMACZILOG_FLAG_HAS_DMA;
1436 			goto no_dma;
1437 		}
1438 		uap->rx_dma_regs = ioremap(r_rxdma.start, 0x100);
1439 		if (uap->rx_dma_regs == NULL) {
1440 			iounmap(uap->tx_dma_regs);
1441 			uap->tx_dma_regs = NULL;
1442 			uap->flags &= ~PMACZILOG_FLAG_HAS_DMA;
1443 			goto no_dma;
1444 		}
1445 		uap->tx_dma_irq = irq_of_parse_and_map(np, 1);
1446 		uap->rx_dma_irq = irq_of_parse_and_map(np, 2);
1447 	}
1448 no_dma:
1449 
1450 	/*
1451 	 * Detect port type
1452 	 */
1453 	if (of_device_is_compatible(np, "cobalt"))
1454 		uap->flags |= PMACZILOG_FLAG_IS_INTMODEM;
1455 	conn = of_get_property(np, "AAPL,connector", &len);
1456 	if (conn && (strcmp(conn, "infrared") == 0))
1457 		uap->flags |= PMACZILOG_FLAG_IS_IRDA;
1458 	uap->port_type = PMAC_SCC_ASYNC;
1459 	/* 1999 Powerbook G3 has slot-names property instead */
1460 	slots = of_get_property(np, "slot-names", &len);
1461 	if (slots && slots->count > 0) {
1462 		if (strcmp(slots->name, "IrDA") == 0)
1463 			uap->flags |= PMACZILOG_FLAG_IS_IRDA;
1464 		else if (strcmp(slots->name, "Modem") == 0)
1465 			uap->flags |= PMACZILOG_FLAG_IS_INTMODEM;
1466 	}
1467 	if (ZS_IS_IRDA(uap))
1468 		uap->port_type = PMAC_SCC_IRDA;
1469 	if (ZS_IS_INTMODEM(uap)) {
1470 		struct device_node* i2c_modem =
1471 			of_find_node_by_name(NULL, "i2c-modem");
1472 		if (i2c_modem) {
1473 			const char* mid =
1474 				of_get_property(i2c_modem, "modem-id", NULL);
1475 			if (mid) switch(*mid) {
1476 			case 0x04 :
1477 			case 0x05 :
1478 			case 0x07 :
1479 			case 0x08 :
1480 			case 0x0b :
1481 			case 0x0c :
1482 				uap->port_type = PMAC_SCC_I2S1;
1483 			}
1484 			printk(KERN_INFO "pmac_zilog: i2c-modem detected, id: %d\n",
1485 				mid ? (*mid) : 0);
1486 			of_node_put(i2c_modem);
1487 		} else {
1488 			printk(KERN_INFO "pmac_zilog: serial modem detected\n");
1489 		}
1490 	}
1491 
1492 	/*
1493 	 * Init remaining bits of "port" structure
1494 	 */
1495 	uap->port.iotype = UPIO_MEM;
1496 	uap->port.irq = irq_of_parse_and_map(np, 0);
1497 	uap->port.uartclk = ZS_CLOCK;
1498 	uap->port.fifosize = 1;
1499 	uap->port.ops = &pmz_pops;
1500 	uap->port.type = PORT_PMAC_ZILOG;
1501 	uap->port.flags = 0;
1502 
1503 	/*
1504 	 * Fixup for the port on Gatwick for which the device-tree has
1505 	 * missing interrupts. Normally, the macio_dev would contain
1506 	 * fixed up interrupt info, but we use the device-tree directly
1507 	 * here due to early probing so we need the fixup too.
1508 	 */
1509 	if (uap->port.irq == 0 &&
1510 	    np->parent && np->parent->parent &&
1511 	    of_device_is_compatible(np->parent->parent, "gatwick")) {
1512 		/* IRQs on gatwick are offset by 64 */
1513 		uap->port.irq = irq_create_mapping(NULL, 64 + 15);
1514 		uap->tx_dma_irq = irq_create_mapping(NULL, 64 + 4);
1515 		uap->rx_dma_irq = irq_create_mapping(NULL, 64 + 5);
1516 	}
1517 
1518 	/* Setup some valid baud rate information in the register
1519 	 * shadows so we don't write crap there before baud rate is
1520 	 * first initialized.
1521 	 */
1522 	pmz_convert_to_zs(uap, CS8, 0, 9600);
1523 
1524 	return 0;
1525 }
1526 
1527 /*
1528  * Get rid of a port on module removal
1529  */
1530 static void pmz_dispose_port(struct uart_pmac_port *uap)
1531 {
1532 	struct device_node *np;
1533 
1534 	np = uap->node;
1535 	iounmap(uap->rx_dma_regs);
1536 	iounmap(uap->tx_dma_regs);
1537 	iounmap(uap->control_reg);
1538 	uap->node = NULL;
1539 	of_node_put(np);
1540 	memset(uap, 0, sizeof(struct uart_pmac_port));
1541 }
1542 
1543 /*
1544  * Called upon match with an escc node in the device-tree.
1545  */
1546 static int pmz_attach(struct macio_dev *mdev, const struct of_device_id *match)
1547 {
1548 	struct uart_pmac_port *uap;
1549 	int i;
1550 
1551 	/* Iterate the pmz_ports array to find a matching entry
1552 	 */
1553 	for (i = 0; i < MAX_ZS_PORTS; i++)
1554 		if (pmz_ports[i].node == mdev->ofdev.dev.of_node)
1555 			break;
1556 	if (i >= MAX_ZS_PORTS)
1557 		return -ENODEV;
1558 
1559 
1560 	uap = &pmz_ports[i];
1561 	uap->dev = mdev;
1562 	uap->port.dev = &mdev->ofdev.dev;
1563 	dev_set_drvdata(&mdev->ofdev.dev, uap);
1564 
1565 	/* We still activate the port even when failing to request resources
1566 	 * to work around bugs in ancient Apple device-trees
1567 	 */
1568 	if (macio_request_resources(uap->dev, "pmac_zilog"))
1569 		printk(KERN_WARNING "%s: Failed to request resource"
1570 		       ", port still active\n",
1571 		       uap->node->name);
1572 	else
1573 		uap->flags |= PMACZILOG_FLAG_RSRC_REQUESTED;
1574 
1575 	return uart_add_one_port(&pmz_uart_reg, &uap->port);
1576 }
1577 
1578 /*
1579  * That one should not be called, macio isn't really a hotswap device,
1580  * we don't expect one of those serial ports to go away...
1581  */
1582 static int pmz_detach(struct macio_dev *mdev)
1583 {
1584 	struct uart_pmac_port	*uap = dev_get_drvdata(&mdev->ofdev.dev);
1585 
1586 	if (!uap)
1587 		return -ENODEV;
1588 
1589 	uart_remove_one_port(&pmz_uart_reg, &uap->port);
1590 
1591 	if (uap->flags & PMACZILOG_FLAG_RSRC_REQUESTED) {
1592 		macio_release_resources(uap->dev);
1593 		uap->flags &= ~PMACZILOG_FLAG_RSRC_REQUESTED;
1594 	}
1595 	dev_set_drvdata(&mdev->ofdev.dev, NULL);
1596 	uap->dev = NULL;
1597 	uap->port.dev = NULL;
1598 
1599 	return 0;
1600 }
1601 
1602 
1603 static int pmz_suspend(struct macio_dev *mdev, pm_message_t pm_state)
1604 {
1605 	struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev);
1606 
1607 	if (uap == NULL) {
1608 		printk("HRM... pmz_suspend with NULL uap\n");
1609 		return 0;
1610 	}
1611 
1612 	uart_suspend_port(&pmz_uart_reg, &uap->port);
1613 
1614 	return 0;
1615 }
1616 
1617 
1618 static int pmz_resume(struct macio_dev *mdev)
1619 {
1620 	struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev);
1621 
1622 	if (uap == NULL)
1623 		return 0;
1624 
1625 	uart_resume_port(&pmz_uart_reg, &uap->port);
1626 
1627 	return 0;
1628 }
1629 
1630 /*
1631  * Probe all ports in the system and build the ports array, we register
1632  * with the serial layer later, so we get a proper struct device which
1633  * allows the tty to attach properly. This is later than it used to be
1634  * but the tty layer really wants it that way.
1635  */
1636 static int __init pmz_probe(void)
1637 {
1638 	struct device_node	*node_p, *node_a, *node_b, *np;
1639 	int			count = 0;
1640 	int			rc;
1641 
1642 	/*
1643 	 * Find all escc chips in the system
1644 	 */
1645 	for_each_node_by_name(node_p, "escc") {
1646 		/*
1647 		 * First get channel A/B node pointers
1648 		 *
1649 		 * TODO: Add routines with proper locking to do that...
1650 		 */
1651 		node_a = node_b = NULL;
1652 		for (np = NULL; (np = of_get_next_child(node_p, np)) != NULL;) {
1653 			if (strncmp(np->name, "ch-a", 4) == 0)
1654 				node_a = of_node_get(np);
1655 			else if (strncmp(np->name, "ch-b", 4) == 0)
1656 				node_b = of_node_get(np);
1657 		}
1658 		if (!node_a && !node_b) {
1659 			of_node_put(node_a);
1660 			of_node_put(node_b);
1661 			printk(KERN_ERR "pmac_zilog: missing node %c for escc %pOF\n",
1662 				(!node_a) ? 'a' : 'b', node_p);
1663 			continue;
1664 		}
1665 
1666 		/*
1667 		 * Fill basic fields in the port structures
1668 		 */
1669 		if (node_b != NULL) {
1670 			pmz_ports[count].mate		= &pmz_ports[count+1];
1671 			pmz_ports[count+1].mate		= &pmz_ports[count];
1672 		}
1673 		pmz_ports[count].flags		= PMACZILOG_FLAG_IS_CHANNEL_A;
1674 		pmz_ports[count].node		= node_a;
1675 		pmz_ports[count+1].node		= node_b;
1676 		pmz_ports[count].port.line	= count;
1677 		pmz_ports[count+1].port.line	= count+1;
1678 
1679 		/*
1680 		 * Setup the ports for real
1681 		 */
1682 		rc = pmz_init_port(&pmz_ports[count]);
1683 		if (rc == 0 && node_b != NULL)
1684 			rc = pmz_init_port(&pmz_ports[count+1]);
1685 		if (rc != 0) {
1686 			of_node_put(node_a);
1687 			of_node_put(node_b);
1688 			memset(&pmz_ports[count], 0, sizeof(struct uart_pmac_port));
1689 			memset(&pmz_ports[count+1], 0, sizeof(struct uart_pmac_port));
1690 			continue;
1691 		}
1692 		count += 2;
1693 	}
1694 	pmz_ports_count = count;
1695 
1696 	return 0;
1697 }
1698 
1699 #else
1700 
1701 extern struct platform_device scc_a_pdev, scc_b_pdev;
1702 
1703 static int __init pmz_init_port(struct uart_pmac_port *uap)
1704 {
1705 	struct resource *r_ports;
1706 	int irq;
1707 
1708 	r_ports = platform_get_resource(uap->pdev, IORESOURCE_MEM, 0);
1709 	irq = platform_get_irq(uap->pdev, 0);
1710 	if (!r_ports || irq <= 0)
1711 		return -ENODEV;
1712 
1713 	uap->port.mapbase  = r_ports->start;
1714 	uap->port.membase  = (unsigned char __iomem *) r_ports->start;
1715 	uap->port.iotype   = UPIO_MEM;
1716 	uap->port.irq      = irq;
1717 	uap->port.uartclk  = ZS_CLOCK;
1718 	uap->port.fifosize = 1;
1719 	uap->port.ops      = &pmz_pops;
1720 	uap->port.type     = PORT_PMAC_ZILOG;
1721 	uap->port.flags    = 0;
1722 
1723 	uap->control_reg   = uap->port.membase;
1724 	uap->data_reg      = uap->control_reg + 4;
1725 	uap->port_type     = 0;
1726 
1727 	pmz_convert_to_zs(uap, CS8, 0, 9600);
1728 
1729 	return 0;
1730 }
1731 
1732 static int __init pmz_probe(void)
1733 {
1734 	int err;
1735 
1736 	pmz_ports_count = 0;
1737 
1738 	pmz_ports[0].port.line = 0;
1739 	pmz_ports[0].flags     = PMACZILOG_FLAG_IS_CHANNEL_A;
1740 	pmz_ports[0].pdev      = &scc_a_pdev;
1741 	err = pmz_init_port(&pmz_ports[0]);
1742 	if (err)
1743 		return err;
1744 	pmz_ports_count++;
1745 
1746 	pmz_ports[0].mate      = &pmz_ports[1];
1747 	pmz_ports[1].mate      = &pmz_ports[0];
1748 	pmz_ports[1].port.line = 1;
1749 	pmz_ports[1].flags     = 0;
1750 	pmz_ports[1].pdev      = &scc_b_pdev;
1751 	err = pmz_init_port(&pmz_ports[1]);
1752 	if (err)
1753 		return err;
1754 	pmz_ports_count++;
1755 
1756 	return 0;
1757 }
1758 
1759 static void pmz_dispose_port(struct uart_pmac_port *uap)
1760 {
1761 	memset(uap, 0, sizeof(struct uart_pmac_port));
1762 }
1763 
1764 static int __init pmz_attach(struct platform_device *pdev)
1765 {
1766 	struct uart_pmac_port *uap;
1767 	int i;
1768 
1769 	/* Iterate the pmz_ports array to find a matching entry */
1770 	for (i = 0; i < pmz_ports_count; i++)
1771 		if (pmz_ports[i].pdev == pdev)
1772 			break;
1773 	if (i >= pmz_ports_count)
1774 		return -ENODEV;
1775 
1776 	uap = &pmz_ports[i];
1777 	uap->port.dev = &pdev->dev;
1778 	platform_set_drvdata(pdev, uap);
1779 
1780 	return uart_add_one_port(&pmz_uart_reg, &uap->port);
1781 }
1782 
1783 static int __exit pmz_detach(struct platform_device *pdev)
1784 {
1785 	struct uart_pmac_port *uap = platform_get_drvdata(pdev);
1786 
1787 	if (!uap)
1788 		return -ENODEV;
1789 
1790 	uart_remove_one_port(&pmz_uart_reg, &uap->port);
1791 
1792 	uap->port.dev = NULL;
1793 
1794 	return 0;
1795 }
1796 
1797 #endif /* !CONFIG_PPC_PMAC */
1798 
1799 #ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
1800 
1801 static void pmz_console_write(struct console *con, const char *s, unsigned int count);
1802 static int __init pmz_console_setup(struct console *co, char *options);
1803 
1804 static struct console pmz_console = {
1805 	.name	=	PMACZILOG_NAME,
1806 	.write	=	pmz_console_write,
1807 	.device	=	uart_console_device,
1808 	.setup	=	pmz_console_setup,
1809 	.flags	=	CON_PRINTBUFFER,
1810 	.index	=	-1,
1811 	.data   =	&pmz_uart_reg,
1812 };
1813 
1814 #define PMACZILOG_CONSOLE	&pmz_console
1815 #else /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
1816 #define PMACZILOG_CONSOLE	(NULL)
1817 #endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
1818 
1819 /*
1820  * Register the driver, console driver and ports with the serial
1821  * core
1822  */
1823 static int __init pmz_register(void)
1824 {
1825 	pmz_uart_reg.nr = pmz_ports_count;
1826 	pmz_uart_reg.cons = PMACZILOG_CONSOLE;
1827 
1828 	/*
1829 	 * Register this driver with the serial core
1830 	 */
1831 	return uart_register_driver(&pmz_uart_reg);
1832 }
1833 
1834 #ifdef CONFIG_PPC_PMAC
1835 
1836 static const struct of_device_id pmz_match[] =
1837 {
1838 	{
1839 	.name		= "ch-a",
1840 	},
1841 	{
1842 	.name		= "ch-b",
1843 	},
1844 	{},
1845 };
1846 MODULE_DEVICE_TABLE (of, pmz_match);
1847 
1848 static struct macio_driver pmz_driver = {
1849 	.driver = {
1850 		.name 		= "pmac_zilog",
1851 		.owner		= THIS_MODULE,
1852 		.of_match_table	= pmz_match,
1853 	},
1854 	.probe		= pmz_attach,
1855 	.remove		= pmz_detach,
1856 	.suspend	= pmz_suspend,
1857 	.resume		= pmz_resume,
1858 };
1859 
1860 #else
1861 
1862 static struct platform_driver pmz_driver = {
1863 	.remove		= __exit_p(pmz_detach),
1864 	.driver		= {
1865 		.name		= "scc",
1866 	},
1867 };
1868 
1869 #endif /* !CONFIG_PPC_PMAC */
1870 
1871 static int __init init_pmz(void)
1872 {
1873 	int rc, i;
1874 	printk(KERN_INFO "%s\n", version);
1875 
1876 	/*
1877 	 * First, we need to do a direct OF-based probe pass. We
1878 	 * do that because we want serial console up before the
1879 	 * macio stuffs calls us back, and since that makes it
1880 	 * easier to pass the proper number of channels to
1881 	 * uart_register_driver()
1882 	 */
1883 	if (pmz_ports_count == 0)
1884 		pmz_probe();
1885 
1886 	/*
1887 	 * Bail early if no port found
1888 	 */
1889 	if (pmz_ports_count == 0)
1890 		return -ENODEV;
1891 
1892 	/*
1893 	 * Now we register with the serial layer
1894 	 */
1895 	rc = pmz_register();
1896 	if (rc) {
1897 		printk(KERN_ERR
1898 			"pmac_zilog: Error registering serial device, disabling pmac_zilog.\n"
1899 		 	"pmac_zilog: Did another serial driver already claim the minors?\n");
1900 		/* effectively "pmz_unprobe()" */
1901 		for (i=0; i < pmz_ports_count; i++)
1902 			pmz_dispose_port(&pmz_ports[i]);
1903 		return rc;
1904 	}
1905 
1906 	/*
1907 	 * Then we register the macio driver itself
1908 	 */
1909 #ifdef CONFIG_PPC_PMAC
1910 	return macio_register_driver(&pmz_driver);
1911 #else
1912 	return platform_driver_probe(&pmz_driver, pmz_attach);
1913 #endif
1914 }
1915 
1916 static void __exit exit_pmz(void)
1917 {
1918 	int i;
1919 
1920 #ifdef CONFIG_PPC_PMAC
1921 	/* Get rid of macio-driver (detach from macio) */
1922 	macio_unregister_driver(&pmz_driver);
1923 #else
1924 	platform_driver_unregister(&pmz_driver);
1925 #endif
1926 
1927 	for (i = 0; i < pmz_ports_count; i++) {
1928 		struct uart_pmac_port *uport = &pmz_ports[i];
1929 #ifdef CONFIG_PPC_PMAC
1930 		if (uport->node != NULL)
1931 			pmz_dispose_port(uport);
1932 #else
1933 		if (uport->pdev != NULL)
1934 			pmz_dispose_port(uport);
1935 #endif
1936 	}
1937 	/* Unregister UART driver */
1938 	uart_unregister_driver(&pmz_uart_reg);
1939 }
1940 
1941 #ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
1942 
1943 static void pmz_console_putchar(struct uart_port *port, int ch)
1944 {
1945 	struct uart_pmac_port *uap =
1946 		container_of(port, struct uart_pmac_port, port);
1947 
1948 	/* Wait for the transmit buffer to empty. */
1949 	while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0)
1950 		udelay(5);
1951 	write_zsdata(uap, ch);
1952 }
1953 
1954 /*
1955  * Print a string to the serial port trying not to disturb
1956  * any possible real use of the port...
1957  */
1958 static void pmz_console_write(struct console *con, const char *s, unsigned int count)
1959 {
1960 	struct uart_pmac_port *uap = &pmz_ports[con->index];
1961 	unsigned long flags;
1962 
1963 	spin_lock_irqsave(&uap->port.lock, flags);
1964 
1965 	/* Turn of interrupts and enable the transmitter. */
1966 	write_zsreg(uap, R1, uap->curregs[1] & ~TxINT_ENAB);
1967 	write_zsreg(uap, R5, uap->curregs[5] | TxENABLE | RTS | DTR);
1968 
1969 	uart_console_write(&uap->port, s, count, pmz_console_putchar);
1970 
1971 	/* Restore the values in the registers. */
1972 	write_zsreg(uap, R1, uap->curregs[1]);
1973 	/* Don't disable the transmitter. */
1974 
1975 	spin_unlock_irqrestore(&uap->port.lock, flags);
1976 }
1977 
1978 /*
1979  * Setup the serial console
1980  */
1981 static int __init pmz_console_setup(struct console *co, char *options)
1982 {
1983 	struct uart_pmac_port *uap;
1984 	struct uart_port *port;
1985 	int baud = 38400;
1986 	int bits = 8;
1987 	int parity = 'n';
1988 	int flow = 'n';
1989 	unsigned long pwr_delay;
1990 
1991 	/*
1992 	 * XServe's default to 57600 bps
1993 	 */
1994 	if (of_machine_is_compatible("RackMac1,1")
1995 	    || of_machine_is_compatible("RackMac1,2")
1996 	    || of_machine_is_compatible("MacRISC4"))
1997 		baud = 57600;
1998 
1999 	/*
2000 	 * Check whether an invalid uart number has been specified, and
2001 	 * if so, search for the first available port that does have
2002 	 * console support.
2003 	 */
2004 	if (co->index >= pmz_ports_count)
2005 		co->index = 0;
2006 	uap = &pmz_ports[co->index];
2007 #ifdef CONFIG_PPC_PMAC
2008 	if (uap->node == NULL)
2009 		return -ENODEV;
2010 #else
2011 	if (uap->pdev == NULL)
2012 		return -ENODEV;
2013 #endif
2014 	port = &uap->port;
2015 
2016 	/*
2017 	 * Mark port as beeing a console
2018 	 */
2019 	uap->flags |= PMACZILOG_FLAG_IS_CONS;
2020 
2021 	/*
2022 	 * Temporary fix for uart layer who didn't setup the spinlock yet
2023 	 */
2024 	spin_lock_init(&port->lock);
2025 
2026 	/*
2027 	 * Enable the hardware
2028 	 */
2029 	pwr_delay = __pmz_startup(uap);
2030 	if (pwr_delay)
2031 		mdelay(pwr_delay);
2032 
2033 	if (options)
2034 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2035 
2036 	return uart_set_options(port, co, baud, parity, bits, flow);
2037 }
2038 
2039 static int __init pmz_console_init(void)
2040 {
2041 	/* Probe ports */
2042 	pmz_probe();
2043 
2044 	if (pmz_ports_count == 0)
2045 		return -ENODEV;
2046 
2047 	/* TODO: Autoprobe console based on OF */
2048 	/* pmz_console.index = i; */
2049 	register_console(&pmz_console);
2050 
2051 	return 0;
2052 
2053 }
2054 console_initcall(pmz_console_init);
2055 #endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
2056 
2057 module_init(init_pmz);
2058 module_exit(exit_pmz);
2059