xref: /linux/drivers/tty/serial/sunsu.c (revision 4359a011e259a4608afc7fb3635370c9d4ba5943)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * su.c: Small serial driver for keyboard/mouse interface on sparc32/PCI
4  *
5  * Copyright (C) 1997  Eddie C. Dost  (ecd@skynet.be)
6  * Copyright (C) 1998-1999  Pete Zaitcev   (zaitcev@yahoo.com)
7  *
8  * This is mainly a variation of 8250.c, credits go to authors mentioned
9  * therein.  In fact this driver should be merged into the generic 8250.c
10  * infrastructure perhaps using a 8250_sparc.c module.
11  *
12  * Fixed to use tty_get_baud_rate().
13  *   Theodore Ts'o <tytso@mit.edu>, 2001-Oct-12
14  *
15  * Converted to new 2.5.x UART layer.
16  *   David S. Miller (davem@davemloft.net), 2002-Jul-29
17  */
18 
19 #include <linux/module.h>
20 #include <linux/kernel.h>
21 #include <linux/spinlock.h>
22 #include <linux/errno.h>
23 #include <linux/tty.h>
24 #include <linux/tty_flip.h>
25 #include <linux/major.h>
26 #include <linux/string.h>
27 #include <linux/ptrace.h>
28 #include <linux/ioport.h>
29 #include <linux/circ_buf.h>
30 #include <linux/serial.h>
31 #include <linux/sysrq.h>
32 #include <linux/console.h>
33 #include <linux/slab.h>
34 #ifdef CONFIG_SERIO
35 #include <linux/serio.h>
36 #endif
37 #include <linux/serial_reg.h>
38 #include <linux/init.h>
39 #include <linux/delay.h>
40 #include <linux/of_device.h>
41 
42 #include <linux/io.h>
43 #include <asm/irq.h>
44 #include <asm/prom.h>
45 #include <asm/setup.h>
46 
47 #include <linux/serial_core.h>
48 #include <linux/sunserialcore.h>
49 
50 /* We are on a NS PC87303 clocked with 24.0 MHz, which results
51  * in a UART clock of 1.8462 MHz.
52  */
53 #define SU_BASE_BAUD	(1846200 / 16)
54 
55 enum su_type { SU_PORT_NONE, SU_PORT_MS, SU_PORT_KBD, SU_PORT_PORT };
56 static char *su_typev[] = { "su(???)", "su(mouse)", "su(kbd)", "su(serial)" };
57 
58 struct serial_uart_config {
59 	char	*name;
60 	int	dfl_xmit_fifo_size;
61 	int	flags;
62 };
63 
64 /*
65  * Here we define the default xmit fifo size used for each type of UART.
66  */
67 static const struct serial_uart_config uart_config[] = {
68 	{ "unknown",	1,	0 },
69 	{ "8250",	1,	0 },
70 	{ "16450",	1,	0 },
71 	{ "16550",	1,	0 },
72 	{ "16550A",	16,	UART_CLEAR_FIFO | UART_USE_FIFO },
73 	{ "Cirrus",	1, 	0 },
74 	{ "ST16650",	1,	UART_CLEAR_FIFO | UART_STARTECH },
75 	{ "ST16650V2",	32,	UART_CLEAR_FIFO | UART_USE_FIFO | UART_STARTECH },
76 	{ "TI16750",	64,	UART_CLEAR_FIFO | UART_USE_FIFO },
77 	{ "Startech",	1,	0 },
78 	{ "16C950/954",	128,	UART_CLEAR_FIFO | UART_USE_FIFO },
79 	{ "ST16654",	64,	UART_CLEAR_FIFO | UART_USE_FIFO | UART_STARTECH },
80 	{ "XR16850",	128,	UART_CLEAR_FIFO | UART_USE_FIFO | UART_STARTECH },
81 	{ "RSA",	2048,	UART_CLEAR_FIFO | UART_USE_FIFO }
82 };
83 
84 struct uart_sunsu_port {
85 	struct uart_port	port;
86 	unsigned char		acr;
87 	unsigned char		ier;
88 	unsigned short		rev;
89 	unsigned char		lcr;
90 	unsigned int		lsr_break_flag;
91 	unsigned int		cflag;
92 
93 	/* Probing information.  */
94 	enum su_type		su_type;
95 	unsigned int		type_probed;	/* XXX Stupid */
96 	unsigned long		reg_size;
97 
98 #ifdef CONFIG_SERIO
99 	struct serio		serio;
100 	int			serio_open;
101 #endif
102 };
103 
104 static unsigned int serial_in(struct uart_sunsu_port *up, int offset)
105 {
106 	offset <<= up->port.regshift;
107 
108 	switch (up->port.iotype) {
109 	case UPIO_HUB6:
110 		outb(up->port.hub6 - 1 + offset, up->port.iobase);
111 		return inb(up->port.iobase + 1);
112 
113 	case UPIO_MEM:
114 		return readb(up->port.membase + offset);
115 
116 	default:
117 		return inb(up->port.iobase + offset);
118 	}
119 }
120 
121 static void serial_out(struct uart_sunsu_port *up, int offset, int value)
122 {
123 #ifndef CONFIG_SPARC64
124 	/*
125 	 * MrCoffee has weird schematics: IRQ4 & P10(?) pins of SuperIO are
126 	 * connected with a gate then go to SlavIO. When IRQ4 goes tristated
127 	 * gate outputs a logical one. Since we use level triggered interrupts
128 	 * we have lockup and watchdog reset. We cannot mask IRQ because
129 	 * keyboard shares IRQ with us (Word has it as Bob Smelik's design).
130 	 * This problem is similar to what Alpha people suffer, see
131 	 * 8250_alpha.c.
132 	 */
133 	if (offset == UART_MCR)
134 		value |= UART_MCR_OUT2;
135 #endif
136 	offset <<= up->port.regshift;
137 
138 	switch (up->port.iotype) {
139 	case UPIO_HUB6:
140 		outb(up->port.hub6 - 1 + offset, up->port.iobase);
141 		outb(value, up->port.iobase + 1);
142 		break;
143 
144 	case UPIO_MEM:
145 		writeb(value, up->port.membase + offset);
146 		break;
147 
148 	default:
149 		outb(value, up->port.iobase + offset);
150 	}
151 }
152 
153 /*
154  * We used to support using pause I/O for certain machines.  We
155  * haven't supported this for a while, but just in case it's badly
156  * needed for certain old 386 machines, I've left these #define's
157  * in....
158  */
159 #define serial_inp(up, offset)		serial_in(up, offset)
160 #define serial_outp(up, offset, value)	serial_out(up, offset, value)
161 
162 
163 /*
164  * For the 16C950
165  */
166 static void serial_icr_write(struct uart_sunsu_port *up, int offset, int value)
167 {
168 	serial_out(up, UART_SCR, offset);
169 	serial_out(up, UART_ICR, value);
170 }
171 
172 #if 0 /* Unused currently */
173 static unsigned int serial_icr_read(struct uart_sunsu_port *up, int offset)
174 {
175 	unsigned int value;
176 
177 	serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
178 	serial_out(up, UART_SCR, offset);
179 	value = serial_in(up, UART_ICR);
180 	serial_icr_write(up, UART_ACR, up->acr);
181 
182 	return value;
183 }
184 #endif
185 
186 #ifdef CONFIG_SERIAL_8250_RSA
187 /*
188  * Attempts to turn on the RSA FIFO.  Returns zero on failure.
189  * We set the port uart clock rate if we succeed.
190  */
191 static int __enable_rsa(struct uart_sunsu_port *up)
192 {
193 	unsigned char mode;
194 	int result;
195 
196 	mode = serial_inp(up, UART_RSA_MSR);
197 	result = mode & UART_RSA_MSR_FIFO;
198 
199 	if (!result) {
200 		serial_outp(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
201 		mode = serial_inp(up, UART_RSA_MSR);
202 		result = mode & UART_RSA_MSR_FIFO;
203 	}
204 
205 	if (result)
206 		up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16;
207 
208 	return result;
209 }
210 
211 static void enable_rsa(struct uart_sunsu_port *up)
212 {
213 	if (up->port.type == PORT_RSA) {
214 		if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
215 			spin_lock_irq(&up->port.lock);
216 			__enable_rsa(up);
217 			spin_unlock_irq(&up->port.lock);
218 		}
219 		if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
220 			serial_outp(up, UART_RSA_FRR, 0);
221 	}
222 }
223 
224 /*
225  * Attempts to turn off the RSA FIFO.  Returns zero on failure.
226  * It is unknown why interrupts were disabled in here.  However,
227  * the caller is expected to preserve this behaviour by grabbing
228  * the spinlock before calling this function.
229  */
230 static void disable_rsa(struct uart_sunsu_port *up)
231 {
232 	unsigned char mode;
233 	int result;
234 
235 	if (up->port.type == PORT_RSA &&
236 	    up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
237 		spin_lock_irq(&up->port.lock);
238 
239 		mode = serial_inp(up, UART_RSA_MSR);
240 		result = !(mode & UART_RSA_MSR_FIFO);
241 
242 		if (!result) {
243 			serial_outp(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
244 			mode = serial_inp(up, UART_RSA_MSR);
245 			result = !(mode & UART_RSA_MSR_FIFO);
246 		}
247 
248 		if (result)
249 			up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
250 		spin_unlock_irq(&up->port.lock);
251 	}
252 }
253 #endif /* CONFIG_SERIAL_8250_RSA */
254 
255 static inline void __stop_tx(struct uart_sunsu_port *p)
256 {
257 	if (p->ier & UART_IER_THRI) {
258 		p->ier &= ~UART_IER_THRI;
259 		serial_out(p, UART_IER, p->ier);
260 	}
261 }
262 
263 static void sunsu_stop_tx(struct uart_port *port)
264 {
265 	struct uart_sunsu_port *up =
266 		container_of(port, struct uart_sunsu_port, port);
267 
268 	__stop_tx(up);
269 
270 	/*
271 	 * We really want to stop the transmitter from sending.
272 	 */
273 	if (up->port.type == PORT_16C950) {
274 		up->acr |= UART_ACR_TXDIS;
275 		serial_icr_write(up, UART_ACR, up->acr);
276 	}
277 }
278 
279 static void sunsu_start_tx(struct uart_port *port)
280 {
281 	struct uart_sunsu_port *up =
282 		container_of(port, struct uart_sunsu_port, port);
283 
284 	if (!(up->ier & UART_IER_THRI)) {
285 		up->ier |= UART_IER_THRI;
286 		serial_out(up, UART_IER, up->ier);
287 	}
288 
289 	/*
290 	 * Re-enable the transmitter if we disabled it.
291 	 */
292 	if (up->port.type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
293 		up->acr &= ~UART_ACR_TXDIS;
294 		serial_icr_write(up, UART_ACR, up->acr);
295 	}
296 }
297 
298 static void sunsu_stop_rx(struct uart_port *port)
299 {
300 	struct uart_sunsu_port *up =
301 		container_of(port, struct uart_sunsu_port, port);
302 
303 	up->ier &= ~UART_IER_RLSI;
304 	up->port.read_status_mask &= ~UART_LSR_DR;
305 	serial_out(up, UART_IER, up->ier);
306 }
307 
308 static void sunsu_enable_ms(struct uart_port *port)
309 {
310 	struct uart_sunsu_port *up =
311 		container_of(port, struct uart_sunsu_port, port);
312 	unsigned long flags;
313 
314 	spin_lock_irqsave(&up->port.lock, flags);
315 	up->ier |= UART_IER_MSI;
316 	serial_out(up, UART_IER, up->ier);
317 	spin_unlock_irqrestore(&up->port.lock, flags);
318 }
319 
320 static void
321 receive_chars(struct uart_sunsu_port *up, unsigned char *status)
322 {
323 	struct tty_port *port = &up->port.state->port;
324 	unsigned char ch, flag;
325 	int max_count = 256;
326 	int saw_console_brk = 0;
327 
328 	do {
329 		ch = serial_inp(up, UART_RX);
330 		flag = TTY_NORMAL;
331 		up->port.icount.rx++;
332 
333 		if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
334 				       UART_LSR_FE | UART_LSR_OE))) {
335 			/*
336 			 * For statistics only
337 			 */
338 			if (*status & UART_LSR_BI) {
339 				*status &= ~(UART_LSR_FE | UART_LSR_PE);
340 				up->port.icount.brk++;
341 				if (up->port.cons != NULL &&
342 				    up->port.line == up->port.cons->index)
343 					saw_console_brk = 1;
344 				/*
345 				 * We do the SysRQ and SAK checking
346 				 * here because otherwise the break
347 				 * may get masked by ignore_status_mask
348 				 * or read_status_mask.
349 				 */
350 				if (uart_handle_break(&up->port))
351 					goto ignore_char;
352 			} else if (*status & UART_LSR_PE)
353 				up->port.icount.parity++;
354 			else if (*status & UART_LSR_FE)
355 				up->port.icount.frame++;
356 			if (*status & UART_LSR_OE)
357 				up->port.icount.overrun++;
358 
359 			/*
360 			 * Mask off conditions which should be ingored.
361 			 */
362 			*status &= up->port.read_status_mask;
363 
364 			if (up->port.cons != NULL &&
365 			    up->port.line == up->port.cons->index) {
366 				/* Recover the break flag from console xmit */
367 				*status |= up->lsr_break_flag;
368 				up->lsr_break_flag = 0;
369 			}
370 
371 			if (*status & UART_LSR_BI) {
372 				flag = TTY_BREAK;
373 			} else if (*status & UART_LSR_PE)
374 				flag = TTY_PARITY;
375 			else if (*status & UART_LSR_FE)
376 				flag = TTY_FRAME;
377 		}
378 		if (uart_handle_sysrq_char(&up->port, ch))
379 			goto ignore_char;
380 		if ((*status & up->port.ignore_status_mask) == 0)
381 			tty_insert_flip_char(port, ch, flag);
382 		if (*status & UART_LSR_OE)
383 			/*
384 			 * Overrun is special, since it's reported
385 			 * immediately, and doesn't affect the current
386 			 * character.
387 			 */
388 			 tty_insert_flip_char(port, 0, TTY_OVERRUN);
389 	ignore_char:
390 		*status = serial_inp(up, UART_LSR);
391 	} while ((*status & UART_LSR_DR) && (max_count-- > 0));
392 
393 	if (saw_console_brk)
394 		sun_do_break();
395 }
396 
397 static void transmit_chars(struct uart_sunsu_port *up)
398 {
399 	struct circ_buf *xmit = &up->port.state->xmit;
400 	int count;
401 
402 	if (up->port.x_char) {
403 		serial_outp(up, UART_TX, up->port.x_char);
404 		up->port.icount.tx++;
405 		up->port.x_char = 0;
406 		return;
407 	}
408 	if (uart_tx_stopped(&up->port)) {
409 		sunsu_stop_tx(&up->port);
410 		return;
411 	}
412 	if (uart_circ_empty(xmit)) {
413 		__stop_tx(up);
414 		return;
415 	}
416 
417 	count = up->port.fifosize;
418 	do {
419 		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
420 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
421 		up->port.icount.tx++;
422 		if (uart_circ_empty(xmit))
423 			break;
424 	} while (--count > 0);
425 
426 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
427 		uart_write_wakeup(&up->port);
428 
429 	if (uart_circ_empty(xmit))
430 		__stop_tx(up);
431 }
432 
433 static void check_modem_status(struct uart_sunsu_port *up)
434 {
435 	int status;
436 
437 	status = serial_in(up, UART_MSR);
438 
439 	if ((status & UART_MSR_ANY_DELTA) == 0)
440 		return;
441 
442 	if (status & UART_MSR_TERI)
443 		up->port.icount.rng++;
444 	if (status & UART_MSR_DDSR)
445 		up->port.icount.dsr++;
446 	if (status & UART_MSR_DDCD)
447 		uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
448 	if (status & UART_MSR_DCTS)
449 		uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
450 
451 	wake_up_interruptible(&up->port.state->port.delta_msr_wait);
452 }
453 
454 static irqreturn_t sunsu_serial_interrupt(int irq, void *dev_id)
455 {
456 	struct uart_sunsu_port *up = dev_id;
457 	unsigned long flags;
458 	unsigned char status;
459 
460 	spin_lock_irqsave(&up->port.lock, flags);
461 
462 	do {
463 		status = serial_inp(up, UART_LSR);
464 		if (status & UART_LSR_DR)
465 			receive_chars(up, &status);
466 		check_modem_status(up);
467 		if (status & UART_LSR_THRE)
468 			transmit_chars(up);
469 
470 		tty_flip_buffer_push(&up->port.state->port);
471 
472 	} while (!(serial_in(up, UART_IIR) & UART_IIR_NO_INT));
473 
474 	spin_unlock_irqrestore(&up->port.lock, flags);
475 
476 	return IRQ_HANDLED;
477 }
478 
479 /* Separate interrupt handling path for keyboard/mouse ports.  */
480 
481 static void
482 sunsu_change_speed(struct uart_port *port, unsigned int cflag,
483 		   unsigned int iflag, unsigned int quot);
484 
485 static void sunsu_change_mouse_baud(struct uart_sunsu_port *up)
486 {
487 	unsigned int cur_cflag = up->cflag;
488 	int quot, new_baud;
489 
490 	up->cflag &= ~CBAUD;
491 	up->cflag |= suncore_mouse_baud_cflag_next(cur_cflag, &new_baud);
492 
493 	quot = up->port.uartclk / (16 * new_baud);
494 
495 	sunsu_change_speed(&up->port, up->cflag, 0, quot);
496 }
497 
498 static void receive_kbd_ms_chars(struct uart_sunsu_port *up, int is_break)
499 {
500 	do {
501 		unsigned char ch = serial_inp(up, UART_RX);
502 
503 		/* Stop-A is handled by drivers/char/keyboard.c now. */
504 		if (up->su_type == SU_PORT_KBD) {
505 #ifdef CONFIG_SERIO
506 			serio_interrupt(&up->serio, ch, 0);
507 #endif
508 		} else if (up->su_type == SU_PORT_MS) {
509 			int ret = suncore_mouse_baud_detection(ch, is_break);
510 
511 			switch (ret) {
512 			case 2:
513 				sunsu_change_mouse_baud(up);
514 				fallthrough;
515 			case 1:
516 				break;
517 
518 			case 0:
519 #ifdef CONFIG_SERIO
520 				serio_interrupt(&up->serio, ch, 0);
521 #endif
522 				break;
523 			}
524 		}
525 	} while (serial_in(up, UART_LSR) & UART_LSR_DR);
526 }
527 
528 static irqreturn_t sunsu_kbd_ms_interrupt(int irq, void *dev_id)
529 {
530 	struct uart_sunsu_port *up = dev_id;
531 
532 	if (!(serial_in(up, UART_IIR) & UART_IIR_NO_INT)) {
533 		unsigned char status = serial_inp(up, UART_LSR);
534 
535 		if ((status & UART_LSR_DR) || (status & UART_LSR_BI))
536 			receive_kbd_ms_chars(up, (status & UART_LSR_BI) != 0);
537 	}
538 
539 	return IRQ_HANDLED;
540 }
541 
542 static unsigned int sunsu_tx_empty(struct uart_port *port)
543 {
544 	struct uart_sunsu_port *up =
545 		container_of(port, struct uart_sunsu_port, port);
546 	unsigned long flags;
547 	unsigned int ret;
548 
549 	spin_lock_irqsave(&up->port.lock, flags);
550 	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
551 	spin_unlock_irqrestore(&up->port.lock, flags);
552 
553 	return ret;
554 }
555 
556 static unsigned int sunsu_get_mctrl(struct uart_port *port)
557 {
558 	struct uart_sunsu_port *up =
559 		container_of(port, struct uart_sunsu_port, port);
560 	unsigned char status;
561 	unsigned int ret;
562 
563 	status = serial_in(up, UART_MSR);
564 
565 	ret = 0;
566 	if (status & UART_MSR_DCD)
567 		ret |= TIOCM_CAR;
568 	if (status & UART_MSR_RI)
569 		ret |= TIOCM_RNG;
570 	if (status & UART_MSR_DSR)
571 		ret |= TIOCM_DSR;
572 	if (status & UART_MSR_CTS)
573 		ret |= TIOCM_CTS;
574 	return ret;
575 }
576 
577 static void sunsu_set_mctrl(struct uart_port *port, unsigned int mctrl)
578 {
579 	struct uart_sunsu_port *up =
580 		container_of(port, struct uart_sunsu_port, port);
581 	unsigned char mcr = 0;
582 
583 	if (mctrl & TIOCM_RTS)
584 		mcr |= UART_MCR_RTS;
585 	if (mctrl & TIOCM_DTR)
586 		mcr |= UART_MCR_DTR;
587 	if (mctrl & TIOCM_OUT1)
588 		mcr |= UART_MCR_OUT1;
589 	if (mctrl & TIOCM_OUT2)
590 		mcr |= UART_MCR_OUT2;
591 	if (mctrl & TIOCM_LOOP)
592 		mcr |= UART_MCR_LOOP;
593 
594 	serial_out(up, UART_MCR, mcr);
595 }
596 
597 static void sunsu_break_ctl(struct uart_port *port, int break_state)
598 {
599 	struct uart_sunsu_port *up =
600 		container_of(port, struct uart_sunsu_port, port);
601 	unsigned long flags;
602 
603 	spin_lock_irqsave(&up->port.lock, flags);
604 	if (break_state == -1)
605 		up->lcr |= UART_LCR_SBC;
606 	else
607 		up->lcr &= ~UART_LCR_SBC;
608 	serial_out(up, UART_LCR, up->lcr);
609 	spin_unlock_irqrestore(&up->port.lock, flags);
610 }
611 
612 static int sunsu_startup(struct uart_port *port)
613 {
614 	struct uart_sunsu_port *up =
615 		container_of(port, struct uart_sunsu_port, port);
616 	unsigned long flags;
617 	int retval;
618 
619 	if (up->port.type == PORT_16C950) {
620 		/* Wake up and initialize UART */
621 		up->acr = 0;
622 		serial_outp(up, UART_LCR, 0xBF);
623 		serial_outp(up, UART_EFR, UART_EFR_ECB);
624 		serial_outp(up, UART_IER, 0);
625 		serial_outp(up, UART_LCR, 0);
626 		serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
627 		serial_outp(up, UART_LCR, 0xBF);
628 		serial_outp(up, UART_EFR, UART_EFR_ECB);
629 		serial_outp(up, UART_LCR, 0);
630 	}
631 
632 #ifdef CONFIG_SERIAL_8250_RSA
633 	/*
634 	 * If this is an RSA port, see if we can kick it up to the
635 	 * higher speed clock.
636 	 */
637 	enable_rsa(up);
638 #endif
639 
640 	/*
641 	 * Clear the FIFO buffers and disable them.
642 	 * (they will be reenabled in set_termios())
643 	 */
644 	if (uart_config[up->port.type].flags & UART_CLEAR_FIFO) {
645 		serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
646 		serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO |
647 				UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
648 		serial_outp(up, UART_FCR, 0);
649 	}
650 
651 	/*
652 	 * Clear the interrupt registers.
653 	 */
654 	(void) serial_inp(up, UART_LSR);
655 	(void) serial_inp(up, UART_RX);
656 	(void) serial_inp(up, UART_IIR);
657 	(void) serial_inp(up, UART_MSR);
658 
659 	/*
660 	 * At this point, there's no way the LSR could still be 0xff;
661 	 * if it is, then bail out, because there's likely no UART
662 	 * here.
663 	 */
664 	if (!(up->port.flags & UPF_BUGGY_UART) &&
665 	    (serial_inp(up, UART_LSR) == 0xff)) {
666 		printk("ttyS%d: LSR safety check engaged!\n", up->port.line);
667 		return -ENODEV;
668 	}
669 
670 	if (up->su_type != SU_PORT_PORT) {
671 		retval = request_irq(up->port.irq, sunsu_kbd_ms_interrupt,
672 				     IRQF_SHARED, su_typev[up->su_type], up);
673 	} else {
674 		retval = request_irq(up->port.irq, sunsu_serial_interrupt,
675 				     IRQF_SHARED, su_typev[up->su_type], up);
676 	}
677 	if (retval) {
678 		printk("su: Cannot register IRQ %d\n", up->port.irq);
679 		return retval;
680 	}
681 
682 	/*
683 	 * Now, initialize the UART
684 	 */
685 	serial_outp(up, UART_LCR, UART_LCR_WLEN8);
686 
687 	spin_lock_irqsave(&up->port.lock, flags);
688 
689 	up->port.mctrl |= TIOCM_OUT2;
690 
691 	sunsu_set_mctrl(&up->port, up->port.mctrl);
692 	spin_unlock_irqrestore(&up->port.lock, flags);
693 
694 	/*
695 	 * Finally, enable interrupts.  Note: Modem status interrupts
696 	 * are set via set_termios(), which will be occurring imminently
697 	 * anyway, so we don't enable them here.
698 	 */
699 	up->ier = UART_IER_RLSI | UART_IER_RDI;
700 	serial_outp(up, UART_IER, up->ier);
701 
702 	if (up->port.flags & UPF_FOURPORT) {
703 		unsigned int icp;
704 		/*
705 		 * Enable interrupts on the AST Fourport board
706 		 */
707 		icp = (up->port.iobase & 0xfe0) | 0x01f;
708 		outb_p(0x80, icp);
709 		(void) inb_p(icp);
710 	}
711 
712 	/*
713 	 * And clear the interrupt registers again for luck.
714 	 */
715 	(void) serial_inp(up, UART_LSR);
716 	(void) serial_inp(up, UART_RX);
717 	(void) serial_inp(up, UART_IIR);
718 	(void) serial_inp(up, UART_MSR);
719 
720 	return 0;
721 }
722 
723 static void sunsu_shutdown(struct uart_port *port)
724 {
725 	struct uart_sunsu_port *up =
726 		container_of(port, struct uart_sunsu_port, port);
727 	unsigned long flags;
728 
729 	/*
730 	 * Disable interrupts from this port
731 	 */
732 	up->ier = 0;
733 	serial_outp(up, UART_IER, 0);
734 
735 	spin_lock_irqsave(&up->port.lock, flags);
736 	if (up->port.flags & UPF_FOURPORT) {
737 		/* reset interrupts on the AST Fourport board */
738 		inb((up->port.iobase & 0xfe0) | 0x1f);
739 		up->port.mctrl |= TIOCM_OUT1;
740 	} else
741 		up->port.mctrl &= ~TIOCM_OUT2;
742 
743 	sunsu_set_mctrl(&up->port, up->port.mctrl);
744 	spin_unlock_irqrestore(&up->port.lock, flags);
745 
746 	/*
747 	 * Disable break condition and FIFOs
748 	 */
749 	serial_out(up, UART_LCR, serial_inp(up, UART_LCR) & ~UART_LCR_SBC);
750 	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO |
751 				  UART_FCR_CLEAR_RCVR |
752 				  UART_FCR_CLEAR_XMIT);
753 	serial_outp(up, UART_FCR, 0);
754 
755 #ifdef CONFIG_SERIAL_8250_RSA
756 	/*
757 	 * Reset the RSA board back to 115kbps compat mode.
758 	 */
759 	disable_rsa(up);
760 #endif
761 
762 	/*
763 	 * Read data port to reset things.
764 	 */
765 	(void) serial_in(up, UART_RX);
766 
767 	free_irq(up->port.irq, up);
768 }
769 
770 static void
771 sunsu_change_speed(struct uart_port *port, unsigned int cflag,
772 		   unsigned int iflag, unsigned int quot)
773 {
774 	struct uart_sunsu_port *up =
775 		container_of(port, struct uart_sunsu_port, port);
776 	unsigned char cval, fcr = 0;
777 	unsigned long flags;
778 
779 	switch (cflag & CSIZE) {
780 	case CS5:
781 		cval = 0x00;
782 		break;
783 	case CS6:
784 		cval = 0x01;
785 		break;
786 	case CS7:
787 		cval = 0x02;
788 		break;
789 	default:
790 	case CS8:
791 		cval = 0x03;
792 		break;
793 	}
794 
795 	if (cflag & CSTOPB)
796 		cval |= 0x04;
797 	if (cflag & PARENB)
798 		cval |= UART_LCR_PARITY;
799 	if (!(cflag & PARODD))
800 		cval |= UART_LCR_EPAR;
801 	if (cflag & CMSPAR)
802 		cval |= UART_LCR_SPAR;
803 
804 	/*
805 	 * Work around a bug in the Oxford Semiconductor 952 rev B
806 	 * chip which causes it to seriously miscalculate baud rates
807 	 * when DLL is 0.
808 	 */
809 	if ((quot & 0xff) == 0 && up->port.type == PORT_16C950 &&
810 	    up->rev == 0x5201)
811 		quot ++;
812 
813 	if (uart_config[up->port.type].flags & UART_USE_FIFO) {
814 		if ((up->port.uartclk / quot) < (2400 * 16))
815 			fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
816 #ifdef CONFIG_SERIAL_8250_RSA
817 		else if (up->port.type == PORT_RSA)
818 			fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_14;
819 #endif
820 		else
821 			fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_8;
822 	}
823 	if (up->port.type == PORT_16750)
824 		fcr |= UART_FCR7_64BYTE;
825 
826 	/*
827 	 * Ok, we're now changing the port state.  Do it with
828 	 * interrupts disabled.
829 	 */
830 	spin_lock_irqsave(&up->port.lock, flags);
831 
832 	/*
833 	 * Update the per-port timeout.
834 	 */
835 	uart_update_timeout(port, cflag, (port->uartclk / (16 * quot)));
836 
837 	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
838 	if (iflag & INPCK)
839 		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
840 	if (iflag & (IGNBRK | BRKINT | PARMRK))
841 		up->port.read_status_mask |= UART_LSR_BI;
842 
843 	/*
844 	 * Characteres to ignore
845 	 */
846 	up->port.ignore_status_mask = 0;
847 	if (iflag & IGNPAR)
848 		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
849 	if (iflag & IGNBRK) {
850 		up->port.ignore_status_mask |= UART_LSR_BI;
851 		/*
852 		 * If we're ignoring parity and break indicators,
853 		 * ignore overruns too (for real raw support).
854 		 */
855 		if (iflag & IGNPAR)
856 			up->port.ignore_status_mask |= UART_LSR_OE;
857 	}
858 
859 	/*
860 	 * ignore all characters if CREAD is not set
861 	 */
862 	if ((cflag & CREAD) == 0)
863 		up->port.ignore_status_mask |= UART_LSR_DR;
864 
865 	/*
866 	 * CTS flow control flag and modem status interrupts
867 	 */
868 	up->ier &= ~UART_IER_MSI;
869 	if (UART_ENABLE_MS(&up->port, cflag))
870 		up->ier |= UART_IER_MSI;
871 
872 	serial_out(up, UART_IER, up->ier);
873 
874 	if (uart_config[up->port.type].flags & UART_STARTECH) {
875 		serial_outp(up, UART_LCR, 0xBF);
876 		serial_outp(up, UART_EFR, cflag & CRTSCTS ? UART_EFR_CTS :0);
877 	}
878 	serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
879 	serial_outp(up, UART_DLL, quot & 0xff);		/* LS of divisor */
880 	serial_outp(up, UART_DLM, quot >> 8);		/* MS of divisor */
881 	if (up->port.type == PORT_16750)
882 		serial_outp(up, UART_FCR, fcr);		/* set fcr */
883 	serial_outp(up, UART_LCR, cval);		/* reset DLAB */
884 	up->lcr = cval;					/* Save LCR */
885 	if (up->port.type != PORT_16750) {
886 		if (fcr & UART_FCR_ENABLE_FIFO) {
887 			/* emulated UARTs (Lucent Venus 167x) need two steps */
888 			serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
889 		}
890 		serial_outp(up, UART_FCR, fcr);		/* set fcr */
891 	}
892 
893 	up->cflag = cflag;
894 
895 	spin_unlock_irqrestore(&up->port.lock, flags);
896 }
897 
898 static void
899 sunsu_set_termios(struct uart_port *port, struct ktermios *termios,
900 		  struct ktermios *old)
901 {
902 	unsigned int baud, quot;
903 
904 	/*
905 	 * Ask the core to calculate the divisor for us.
906 	 */
907 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
908 	quot = uart_get_divisor(port, baud);
909 
910 	sunsu_change_speed(port, termios->c_cflag, termios->c_iflag, quot);
911 }
912 
913 static void sunsu_release_port(struct uart_port *port)
914 {
915 }
916 
917 static int sunsu_request_port(struct uart_port *port)
918 {
919 	return 0;
920 }
921 
922 static void sunsu_config_port(struct uart_port *port, int flags)
923 {
924 	struct uart_sunsu_port *up =
925 		container_of(port, struct uart_sunsu_port, port);
926 
927 	if (flags & UART_CONFIG_TYPE) {
928 		/*
929 		 * We are supposed to call autoconfig here, but this requires
930 		 * splitting all the OBP probing crap from the UART probing.
931 		 * We'll do it when we kill sunsu.c altogether.
932 		 */
933 		port->type = up->type_probed;	/* XXX */
934 	}
935 }
936 
937 static int
938 sunsu_verify_port(struct uart_port *port, struct serial_struct *ser)
939 {
940 	return -EINVAL;
941 }
942 
943 static const char *
944 sunsu_type(struct uart_port *port)
945 {
946 	int type = port->type;
947 
948 	if (type >= ARRAY_SIZE(uart_config))
949 		type = 0;
950 	return uart_config[type].name;
951 }
952 
953 static const struct uart_ops sunsu_pops = {
954 	.tx_empty	= sunsu_tx_empty,
955 	.set_mctrl	= sunsu_set_mctrl,
956 	.get_mctrl	= sunsu_get_mctrl,
957 	.stop_tx	= sunsu_stop_tx,
958 	.start_tx	= sunsu_start_tx,
959 	.stop_rx	= sunsu_stop_rx,
960 	.enable_ms	= sunsu_enable_ms,
961 	.break_ctl	= sunsu_break_ctl,
962 	.startup	= sunsu_startup,
963 	.shutdown	= sunsu_shutdown,
964 	.set_termios	= sunsu_set_termios,
965 	.type		= sunsu_type,
966 	.release_port	= sunsu_release_port,
967 	.request_port	= sunsu_request_port,
968 	.config_port	= sunsu_config_port,
969 	.verify_port	= sunsu_verify_port,
970 };
971 
972 #define UART_NR	4
973 
974 static struct uart_sunsu_port sunsu_ports[UART_NR];
975 static int nr_inst; /* Number of already registered ports */
976 
977 #ifdef CONFIG_SERIO
978 
979 static DEFINE_SPINLOCK(sunsu_serio_lock);
980 
981 static int sunsu_serio_write(struct serio *serio, unsigned char ch)
982 {
983 	struct uart_sunsu_port *up = serio->port_data;
984 	unsigned long flags;
985 	int lsr;
986 
987 	spin_lock_irqsave(&sunsu_serio_lock, flags);
988 
989 	do {
990 		lsr = serial_in(up, UART_LSR);
991 	} while (!(lsr & UART_LSR_THRE));
992 
993 	/* Send the character out. */
994 	serial_out(up, UART_TX, ch);
995 
996 	spin_unlock_irqrestore(&sunsu_serio_lock, flags);
997 
998 	return 0;
999 }
1000 
1001 static int sunsu_serio_open(struct serio *serio)
1002 {
1003 	struct uart_sunsu_port *up = serio->port_data;
1004 	unsigned long flags;
1005 	int ret;
1006 
1007 	spin_lock_irqsave(&sunsu_serio_lock, flags);
1008 	if (!up->serio_open) {
1009 		up->serio_open = 1;
1010 		ret = 0;
1011 	} else
1012 		ret = -EBUSY;
1013 	spin_unlock_irqrestore(&sunsu_serio_lock, flags);
1014 
1015 	return ret;
1016 }
1017 
1018 static void sunsu_serio_close(struct serio *serio)
1019 {
1020 	struct uart_sunsu_port *up = serio->port_data;
1021 	unsigned long flags;
1022 
1023 	spin_lock_irqsave(&sunsu_serio_lock, flags);
1024 	up->serio_open = 0;
1025 	spin_unlock_irqrestore(&sunsu_serio_lock, flags);
1026 }
1027 
1028 #endif /* CONFIG_SERIO */
1029 
1030 static void sunsu_autoconfig(struct uart_sunsu_port *up)
1031 {
1032 	unsigned char status1, status2, scratch, scratch2, scratch3;
1033 	unsigned char save_lcr, save_mcr;
1034 	unsigned long flags;
1035 
1036 	if (up->su_type == SU_PORT_NONE)
1037 		return;
1038 
1039 	up->type_probed = PORT_UNKNOWN;
1040 	up->port.iotype = UPIO_MEM;
1041 
1042 	spin_lock_irqsave(&up->port.lock, flags);
1043 
1044 	if (!(up->port.flags & UPF_BUGGY_UART)) {
1045 		/*
1046 		 * Do a simple existence test first; if we fail this, there's
1047 		 * no point trying anything else.
1048 		 *
1049 		 * 0x80 is used as a nonsense port to prevent against false
1050 		 * positives due to ISA bus float.  The assumption is that
1051 		 * 0x80 is a non-existent port; which should be safe since
1052 		 * include/asm/io.h also makes this assumption.
1053 		 */
1054 		scratch = serial_inp(up, UART_IER);
1055 		serial_outp(up, UART_IER, 0);
1056 #ifdef __i386__
1057 		outb(0xff, 0x080);
1058 #endif
1059 		scratch2 = serial_inp(up, UART_IER);
1060 		serial_outp(up, UART_IER, 0x0f);
1061 #ifdef __i386__
1062 		outb(0, 0x080);
1063 #endif
1064 		scratch3 = serial_inp(up, UART_IER);
1065 		serial_outp(up, UART_IER, scratch);
1066 		if (scratch2 != 0 || scratch3 != 0x0F)
1067 			goto out;	/* We failed; there's nothing here */
1068 	}
1069 
1070 	save_mcr = serial_in(up, UART_MCR);
1071 	save_lcr = serial_in(up, UART_LCR);
1072 
1073 	/*
1074 	 * Check to see if a UART is really there.  Certain broken
1075 	 * internal modems based on the Rockwell chipset fail this
1076 	 * test, because they apparently don't implement the loopback
1077 	 * test mode.  So this test is skipped on the COM 1 through
1078 	 * COM 4 ports.  This *should* be safe, since no board
1079 	 * manufacturer would be stupid enough to design a board
1080 	 * that conflicts with COM 1-4 --- we hope!
1081 	 */
1082 	if (!(up->port.flags & UPF_SKIP_TEST)) {
1083 		serial_outp(up, UART_MCR, UART_MCR_LOOP | 0x0A);
1084 		status1 = serial_inp(up, UART_MSR) & 0xF0;
1085 		serial_outp(up, UART_MCR, save_mcr);
1086 		if (status1 != 0x90)
1087 			goto out;	/* We failed loopback test */
1088 	}
1089 	serial_outp(up, UART_LCR, 0xBF);	/* set up for StarTech test */
1090 	serial_outp(up, UART_EFR, 0);		/* EFR is the same as FCR */
1091 	serial_outp(up, UART_LCR, 0);
1092 	serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1093 	scratch = serial_in(up, UART_IIR) >> 6;
1094 	switch (scratch) {
1095 		case 0:
1096 			up->port.type = PORT_16450;
1097 			break;
1098 		case 1:
1099 			up->port.type = PORT_UNKNOWN;
1100 			break;
1101 		case 2:
1102 			up->port.type = PORT_16550;
1103 			break;
1104 		case 3:
1105 			up->port.type = PORT_16550A;
1106 			break;
1107 	}
1108 	if (up->port.type == PORT_16550A) {
1109 		/* Check for Startech UART's */
1110 		serial_outp(up, UART_LCR, UART_LCR_DLAB);
1111 		if (serial_in(up, UART_EFR) == 0) {
1112 			up->port.type = PORT_16650;
1113 		} else {
1114 			serial_outp(up, UART_LCR, 0xBF);
1115 			if (serial_in(up, UART_EFR) == 0)
1116 				up->port.type = PORT_16650V2;
1117 		}
1118 	}
1119 	if (up->port.type == PORT_16550A) {
1120 		/* Check for TI 16750 */
1121 		serial_outp(up, UART_LCR, save_lcr | UART_LCR_DLAB);
1122 		serial_outp(up, UART_FCR,
1123 			    UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
1124 		scratch = serial_in(up, UART_IIR) >> 5;
1125 		if (scratch == 7) {
1126 			/*
1127 			 * If this is a 16750, and not a cheap UART
1128 			 * clone, then it should only go into 64 byte
1129 			 * mode if the UART_FCR7_64BYTE bit was set
1130 			 * while UART_LCR_DLAB was latched.
1131 			 */
1132  			serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1133 			serial_outp(up, UART_LCR, 0);
1134 			serial_outp(up, UART_FCR,
1135 				    UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
1136 			scratch = serial_in(up, UART_IIR) >> 5;
1137 			if (scratch == 6)
1138 				up->port.type = PORT_16750;
1139 		}
1140 		serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO);
1141 	}
1142 	serial_outp(up, UART_LCR, save_lcr);
1143 	if (up->port.type == PORT_16450) {
1144 		scratch = serial_in(up, UART_SCR);
1145 		serial_outp(up, UART_SCR, 0xa5);
1146 		status1 = serial_in(up, UART_SCR);
1147 		serial_outp(up, UART_SCR, 0x5a);
1148 		status2 = serial_in(up, UART_SCR);
1149 		serial_outp(up, UART_SCR, scratch);
1150 
1151 		if ((status1 != 0xa5) || (status2 != 0x5a))
1152 			up->port.type = PORT_8250;
1153 	}
1154 
1155 	up->port.fifosize = uart_config[up->port.type].dfl_xmit_fifo_size;
1156 
1157 	if (up->port.type == PORT_UNKNOWN)
1158 		goto out;
1159 	up->type_probed = up->port.type;	/* XXX */
1160 
1161 	/*
1162 	 * Reset the UART.
1163 	 */
1164 #ifdef CONFIG_SERIAL_8250_RSA
1165 	if (up->port.type == PORT_RSA)
1166 		serial_outp(up, UART_RSA_FRR, 0);
1167 #endif
1168 	serial_outp(up, UART_MCR, save_mcr);
1169 	serial_outp(up, UART_FCR, (UART_FCR_ENABLE_FIFO |
1170 				     UART_FCR_CLEAR_RCVR |
1171 				     UART_FCR_CLEAR_XMIT));
1172 	serial_outp(up, UART_FCR, 0);
1173 	(void)serial_in(up, UART_RX);
1174 	serial_outp(up, UART_IER, 0);
1175 
1176 out:
1177 	spin_unlock_irqrestore(&up->port.lock, flags);
1178 }
1179 
1180 static struct uart_driver sunsu_reg = {
1181 	.owner			= THIS_MODULE,
1182 	.driver_name		= "sunsu",
1183 	.dev_name		= "ttyS",
1184 	.major			= TTY_MAJOR,
1185 };
1186 
1187 static int sunsu_kbd_ms_init(struct uart_sunsu_port *up)
1188 {
1189 	int quot, baud;
1190 #ifdef CONFIG_SERIO
1191 	struct serio *serio;
1192 #endif
1193 
1194 	if (up->su_type == SU_PORT_KBD) {
1195 		up->cflag = B1200 | CS8 | CLOCAL | CREAD;
1196 		baud = 1200;
1197 	} else {
1198 		up->cflag = B4800 | CS8 | CLOCAL | CREAD;
1199 		baud = 4800;
1200 	}
1201 	quot = up->port.uartclk / (16 * baud);
1202 
1203 	sunsu_autoconfig(up);
1204 	if (up->port.type == PORT_UNKNOWN)
1205 		return -ENODEV;
1206 
1207 	printk("%pOF: %s port at %llx, irq %u\n",
1208 	       up->port.dev->of_node,
1209 	       (up->su_type == SU_PORT_KBD) ? "Keyboard" : "Mouse",
1210 	       (unsigned long long) up->port.mapbase,
1211 	       up->port.irq);
1212 
1213 #ifdef CONFIG_SERIO
1214 	serio = &up->serio;
1215 	serio->port_data = up;
1216 
1217 	serio->id.type = SERIO_RS232;
1218 	if (up->su_type == SU_PORT_KBD) {
1219 		serio->id.proto = SERIO_SUNKBD;
1220 		strlcpy(serio->name, "sukbd", sizeof(serio->name));
1221 	} else {
1222 		serio->id.proto = SERIO_SUN;
1223 		serio->id.extra = 1;
1224 		strlcpy(serio->name, "sums", sizeof(serio->name));
1225 	}
1226 	strlcpy(serio->phys,
1227 		(!(up->port.line & 1) ? "su/serio0" : "su/serio1"),
1228 		sizeof(serio->phys));
1229 
1230 	serio->write = sunsu_serio_write;
1231 	serio->open = sunsu_serio_open;
1232 	serio->close = sunsu_serio_close;
1233 	serio->dev.parent = up->port.dev;
1234 
1235 	serio_register_port(serio);
1236 #endif
1237 
1238 	sunsu_change_speed(&up->port, up->cflag, 0, quot);
1239 
1240 	sunsu_startup(&up->port);
1241 	return 0;
1242 }
1243 
1244 /*
1245  * ------------------------------------------------------------
1246  * Serial console driver
1247  * ------------------------------------------------------------
1248  */
1249 
1250 #ifdef CONFIG_SERIAL_SUNSU_CONSOLE
1251 
1252 /*
1253  *	Wait for transmitter & holding register to empty
1254  */
1255 static void wait_for_xmitr(struct uart_sunsu_port *up)
1256 {
1257 	unsigned int status, tmout = 10000;
1258 
1259 	/* Wait up to 10ms for the character(s) to be sent. */
1260 	do {
1261 		status = serial_in(up, UART_LSR);
1262 
1263 		if (status & UART_LSR_BI)
1264 			up->lsr_break_flag = UART_LSR_BI;
1265 
1266 		if (--tmout == 0)
1267 			break;
1268 		udelay(1);
1269 	} while (!uart_lsr_tx_empty(status));
1270 
1271 	/* Wait up to 1s for flow control if necessary */
1272 	if (up->port.flags & UPF_CONS_FLOW) {
1273 		tmout = 1000000;
1274 		while (--tmout &&
1275 		       ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
1276 			udelay(1);
1277 	}
1278 }
1279 
1280 static void sunsu_console_putchar(struct uart_port *port, unsigned char ch)
1281 {
1282 	struct uart_sunsu_port *up =
1283 		container_of(port, struct uart_sunsu_port, port);
1284 
1285 	wait_for_xmitr(up);
1286 	serial_out(up, UART_TX, ch);
1287 }
1288 
1289 /*
1290  *	Print a string to the serial port trying not to disturb
1291  *	any possible real use of the port...
1292  */
1293 static void sunsu_console_write(struct console *co, const char *s,
1294 				unsigned int count)
1295 {
1296 	struct uart_sunsu_port *up = &sunsu_ports[co->index];
1297 	unsigned long flags;
1298 	unsigned int ier;
1299 	int locked = 1;
1300 
1301 	if (up->port.sysrq || oops_in_progress)
1302 		locked = spin_trylock_irqsave(&up->port.lock, flags);
1303 	else
1304 		spin_lock_irqsave(&up->port.lock, flags);
1305 
1306 	/*
1307 	 *	First save the UER then disable the interrupts
1308 	 */
1309 	ier = serial_in(up, UART_IER);
1310 	serial_out(up, UART_IER, 0);
1311 
1312 	uart_console_write(&up->port, s, count, sunsu_console_putchar);
1313 
1314 	/*
1315 	 *	Finally, wait for transmitter to become empty
1316 	 *	and restore the IER
1317 	 */
1318 	wait_for_xmitr(up);
1319 	serial_out(up, UART_IER, ier);
1320 
1321 	if (locked)
1322 		spin_unlock_irqrestore(&up->port.lock, flags);
1323 }
1324 
1325 /*
1326  *	Setup initial baud/bits/parity. We do two things here:
1327  *	- construct a cflag setting for the first su_open()
1328  *	- initialize the serial port
1329  *	Return non-zero if we didn't find a serial port.
1330  */
1331 static int __init sunsu_console_setup(struct console *co, char *options)
1332 {
1333 	static struct ktermios dummy;
1334 	struct ktermios termios;
1335 	struct uart_port *port;
1336 
1337 	printk("Console: ttyS%d (SU)\n",
1338 	       (sunsu_reg.minor - 64) + co->index);
1339 
1340 	if (co->index > nr_inst)
1341 		return -ENODEV;
1342 	port = &sunsu_ports[co->index].port;
1343 
1344 	/*
1345 	 * Temporary fix.
1346 	 */
1347 	spin_lock_init(&port->lock);
1348 
1349 	/* Get firmware console settings.  */
1350 	sunserial_console_termios(co, port->dev->of_node);
1351 
1352 	memset(&termios, 0, sizeof(struct ktermios));
1353 	termios.c_cflag = co->cflag;
1354 	port->mctrl |= TIOCM_DTR;
1355 	port->ops->set_termios(port, &termios, &dummy);
1356 
1357 	return 0;
1358 }
1359 
1360 static struct console sunsu_console = {
1361 	.name	=	"ttyS",
1362 	.write	=	sunsu_console_write,
1363 	.device	=	uart_console_device,
1364 	.setup	=	sunsu_console_setup,
1365 	.flags	=	CON_PRINTBUFFER,
1366 	.index	=	-1,
1367 	.data	=	&sunsu_reg,
1368 };
1369 
1370 /*
1371  *	Register console.
1372  */
1373 
1374 static inline struct console *SUNSU_CONSOLE(void)
1375 {
1376 	return &sunsu_console;
1377 }
1378 #else
1379 #define SUNSU_CONSOLE()			(NULL)
1380 #define sunsu_serial_console_init()	do { } while (0)
1381 #endif
1382 
1383 static enum su_type su_get_type(struct device_node *dp)
1384 {
1385 	struct device_node *ap = of_find_node_by_path("/aliases");
1386 	enum su_type rc = SU_PORT_PORT;
1387 
1388 	if (ap) {
1389 		const char *keyb = of_get_property(ap, "keyboard", NULL);
1390 		const char *ms = of_get_property(ap, "mouse", NULL);
1391 		struct device_node *match;
1392 
1393 		if (keyb) {
1394 			match = of_find_node_by_path(keyb);
1395 
1396 			/*
1397 			 * The pointer is used as an identifier not
1398 			 * as a pointer, we can drop the refcount on
1399 			 * the of__node immediately after getting it.
1400 			 */
1401 			of_node_put(match);
1402 
1403 			if (dp == match) {
1404 				rc = SU_PORT_KBD;
1405 				goto out;
1406 			}
1407 		}
1408 		if (ms) {
1409 			match = of_find_node_by_path(ms);
1410 
1411 			of_node_put(match);
1412 
1413 			if (dp == match) {
1414 				rc = SU_PORT_MS;
1415 				goto out;
1416 			}
1417 		}
1418 	}
1419 
1420 out:
1421 	of_node_put(ap);
1422 	return rc;
1423 }
1424 
1425 static int su_probe(struct platform_device *op)
1426 {
1427 	struct device_node *dp = op->dev.of_node;
1428 	struct uart_sunsu_port *up;
1429 	struct resource *rp;
1430 	enum su_type type;
1431 	bool ignore_line;
1432 	int err;
1433 
1434 	type = su_get_type(dp);
1435 	if (type == SU_PORT_PORT) {
1436 		if (nr_inst >= UART_NR)
1437 			return -EINVAL;
1438 		up = &sunsu_ports[nr_inst];
1439 	} else {
1440 		up = kzalloc(sizeof(*up), GFP_KERNEL);
1441 		if (!up)
1442 			return -ENOMEM;
1443 	}
1444 
1445 	up->port.line = nr_inst;
1446 
1447 	spin_lock_init(&up->port.lock);
1448 
1449 	up->su_type = type;
1450 
1451 	rp = &op->resource[0];
1452 	up->port.mapbase = rp->start;
1453 	up->reg_size = resource_size(rp);
1454 	up->port.membase = of_ioremap(rp, 0, up->reg_size, "su");
1455 	if (!up->port.membase) {
1456 		if (type != SU_PORT_PORT)
1457 			kfree(up);
1458 		return -ENOMEM;
1459 	}
1460 
1461 	up->port.irq = op->archdata.irqs[0];
1462 
1463 	up->port.dev = &op->dev;
1464 
1465 	up->port.type = PORT_UNKNOWN;
1466 	up->port.uartclk = (SU_BASE_BAUD * 16);
1467 	up->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SUNSU_CONSOLE);
1468 
1469 	err = 0;
1470 	if (up->su_type == SU_PORT_KBD || up->su_type == SU_PORT_MS) {
1471 		err = sunsu_kbd_ms_init(up);
1472 		if (err) {
1473 			of_iounmap(&op->resource[0],
1474 				   up->port.membase, up->reg_size);
1475 			kfree(up);
1476 			return err;
1477 		}
1478 		platform_set_drvdata(op, up);
1479 
1480 		nr_inst++;
1481 
1482 		return 0;
1483 	}
1484 
1485 	up->port.flags |= UPF_BOOT_AUTOCONF;
1486 
1487 	sunsu_autoconfig(up);
1488 
1489 	err = -ENODEV;
1490 	if (up->port.type == PORT_UNKNOWN)
1491 		goto out_unmap;
1492 
1493 	up->port.ops = &sunsu_pops;
1494 
1495 	ignore_line = false;
1496 	if (of_node_name_eq(dp, "rsc-console") ||
1497 	    of_node_name_eq(dp, "lom-console"))
1498 		ignore_line = true;
1499 
1500 	sunserial_console_match(SUNSU_CONSOLE(), dp,
1501 				&sunsu_reg, up->port.line,
1502 				ignore_line);
1503 	err = uart_add_one_port(&sunsu_reg, &up->port);
1504 	if (err)
1505 		goto out_unmap;
1506 
1507 	platform_set_drvdata(op, up);
1508 
1509 	nr_inst++;
1510 
1511 	return 0;
1512 
1513 out_unmap:
1514 	of_iounmap(&op->resource[0], up->port.membase, up->reg_size);
1515 	kfree(up);
1516 	return err;
1517 }
1518 
1519 static int su_remove(struct platform_device *op)
1520 {
1521 	struct uart_sunsu_port *up = platform_get_drvdata(op);
1522 	bool kbdms = false;
1523 
1524 	if (up->su_type == SU_PORT_MS ||
1525 	    up->su_type == SU_PORT_KBD)
1526 		kbdms = true;
1527 
1528 	if (kbdms) {
1529 #ifdef CONFIG_SERIO
1530 		serio_unregister_port(&up->serio);
1531 #endif
1532 	} else if (up->port.type != PORT_UNKNOWN)
1533 		uart_remove_one_port(&sunsu_reg, &up->port);
1534 
1535 	if (up->port.membase)
1536 		of_iounmap(&op->resource[0], up->port.membase, up->reg_size);
1537 
1538 	if (kbdms)
1539 		kfree(up);
1540 
1541 	return 0;
1542 }
1543 
1544 static const struct of_device_id su_match[] = {
1545 	{
1546 		.name = "su",
1547 	},
1548 	{
1549 		.name = "su_pnp",
1550 	},
1551 	{
1552 		.name = "serial",
1553 		.compatible = "su",
1554 	},
1555 	{
1556 		.type = "serial",
1557 		.compatible = "su",
1558 	},
1559 	{},
1560 };
1561 MODULE_DEVICE_TABLE(of, su_match);
1562 
1563 static struct platform_driver su_driver = {
1564 	.driver = {
1565 		.name = "su",
1566 		.of_match_table = su_match,
1567 	},
1568 	.probe		= su_probe,
1569 	.remove		= su_remove,
1570 };
1571 
1572 static int __init sunsu_init(void)
1573 {
1574 	struct device_node *dp;
1575 	int err;
1576 	int num_uart = 0;
1577 
1578 	for_each_node_by_name(dp, "su") {
1579 		if (su_get_type(dp) == SU_PORT_PORT)
1580 			num_uart++;
1581 	}
1582 	for_each_node_by_name(dp, "su_pnp") {
1583 		if (su_get_type(dp) == SU_PORT_PORT)
1584 			num_uart++;
1585 	}
1586 	for_each_node_by_name(dp, "serial") {
1587 		if (of_device_is_compatible(dp, "su")) {
1588 			if (su_get_type(dp) == SU_PORT_PORT)
1589 				num_uart++;
1590 		}
1591 	}
1592 	for_each_node_by_type(dp, "serial") {
1593 		if (of_device_is_compatible(dp, "su")) {
1594 			if (su_get_type(dp) == SU_PORT_PORT)
1595 				num_uart++;
1596 		}
1597 	}
1598 
1599 	if (num_uart) {
1600 		err = sunserial_register_minors(&sunsu_reg, num_uart);
1601 		if (err)
1602 			return err;
1603 	}
1604 
1605 	err = platform_driver_register(&su_driver);
1606 	if (err && num_uart)
1607 		sunserial_unregister_minors(&sunsu_reg, num_uart);
1608 
1609 	return err;
1610 }
1611 
1612 static void __exit sunsu_exit(void)
1613 {
1614 	platform_driver_unregister(&su_driver);
1615 	if (sunsu_reg.nr)
1616 		sunserial_unregister_minors(&sunsu_reg, sunsu_reg.nr);
1617 }
1618 
1619 module_init(sunsu_init);
1620 module_exit(sunsu_exit);
1621 
1622 MODULE_AUTHOR("Eddie C. Dost, Peter Zaitcev, and David S. Miller");
1623 MODULE_DESCRIPTION("Sun SU serial port driver");
1624 MODULE_VERSION("2.0");
1625 MODULE_LICENSE("GPL");
1626