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