xref: /openbmc/linux/drivers/tty/serial/sa1100.c (revision 0c6dfa75)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  Driver for SA11x0 serial ports
4  *
5  *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6  *
7  *  Copyright (C) 2000 Deep Blue Solutions Ltd.
8  */
9 
10 #include <linux/module.h>
11 #include <linux/ioport.h>
12 #include <linux/init.h>
13 #include <linux/console.h>
14 #include <linux/sysrq.h>
15 #include <linux/platform_data/sa11x0-serial.h>
16 #include <linux/platform_device.h>
17 #include <linux/tty.h>
18 #include <linux/tty_flip.h>
19 #include <linux/serial_core.h>
20 #include <linux/serial.h>
21 #include <linux/io.h>
22 
23 #include <asm/irq.h>
24 #include <mach/hardware.h>
25 #include <mach/irqs.h>
26 
27 #include "serial_mctrl_gpio.h"
28 
29 /* We've been assigned a range on the "Low-density serial ports" major */
30 #define SERIAL_SA1100_MAJOR	204
31 #define MINOR_START		5
32 
33 #define NR_PORTS		3
34 
35 #define SA1100_ISR_PASS_LIMIT	256
36 
37 /*
38  * Convert from ignore_status_mask or read_status_mask to UTSR[01]
39  */
40 #define SM_TO_UTSR0(x)	((x) & 0xff)
41 #define SM_TO_UTSR1(x)	((x) >> 8)
42 #define UTSR0_TO_SM(x)	((x))
43 #define UTSR1_TO_SM(x)	((x) << 8)
44 
45 #define UART_GET_UTCR0(sport)	__raw_readl((sport)->port.membase + UTCR0)
46 #define UART_GET_UTCR1(sport)	__raw_readl((sport)->port.membase + UTCR1)
47 #define UART_GET_UTCR2(sport)	__raw_readl((sport)->port.membase + UTCR2)
48 #define UART_GET_UTCR3(sport)	__raw_readl((sport)->port.membase + UTCR3)
49 #define UART_GET_UTSR0(sport)	__raw_readl((sport)->port.membase + UTSR0)
50 #define UART_GET_UTSR1(sport)	__raw_readl((sport)->port.membase + UTSR1)
51 #define UART_GET_CHAR(sport)	__raw_readl((sport)->port.membase + UTDR)
52 
53 #define UART_PUT_UTCR0(sport,v)	__raw_writel((v),(sport)->port.membase + UTCR0)
54 #define UART_PUT_UTCR1(sport,v)	__raw_writel((v),(sport)->port.membase + UTCR1)
55 #define UART_PUT_UTCR2(sport,v)	__raw_writel((v),(sport)->port.membase + UTCR2)
56 #define UART_PUT_UTCR3(sport,v)	__raw_writel((v),(sport)->port.membase + UTCR3)
57 #define UART_PUT_UTSR0(sport,v)	__raw_writel((v),(sport)->port.membase + UTSR0)
58 #define UART_PUT_UTSR1(sport,v)	__raw_writel((v),(sport)->port.membase + UTSR1)
59 #define UART_PUT_CHAR(sport,v)	__raw_writel((v),(sport)->port.membase + UTDR)
60 
61 /*
62  * This is the size of our serial port register set.
63  */
64 #define UART_PORT_SIZE	0x24
65 
66 /*
67  * This determines how often we check the modem status signals
68  * for any change.  They generally aren't connected to an IRQ
69  * so we have to poll them.  We also check immediately before
70  * filling the TX fifo incase CTS has been dropped.
71  */
72 #define MCTRL_TIMEOUT	(250*HZ/1000)
73 
74 struct sa1100_port {
75 	struct uart_port	port;
76 	struct timer_list	timer;
77 	unsigned int		old_status;
78 	struct mctrl_gpios	*gpios;
79 };
80 
81 /*
82  * Handle any change of modem status signal since we were last called.
83  */
84 static void sa1100_mctrl_check(struct sa1100_port *sport)
85 {
86 	unsigned int status, changed;
87 
88 	status = sport->port.ops->get_mctrl(&sport->port);
89 	changed = status ^ sport->old_status;
90 
91 	if (changed == 0)
92 		return;
93 
94 	sport->old_status = status;
95 
96 	if (changed & TIOCM_RI)
97 		sport->port.icount.rng++;
98 	if (changed & TIOCM_DSR)
99 		sport->port.icount.dsr++;
100 	if (changed & TIOCM_CAR)
101 		uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
102 	if (changed & TIOCM_CTS)
103 		uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
104 
105 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
106 }
107 
108 /*
109  * This is our per-port timeout handler, for checking the
110  * modem status signals.
111  */
112 static void sa1100_timeout(struct timer_list *t)
113 {
114 	struct sa1100_port *sport = from_timer(sport, t, timer);
115 	unsigned long flags;
116 
117 	if (sport->port.state) {
118 		spin_lock_irqsave(&sport->port.lock, flags);
119 		sa1100_mctrl_check(sport);
120 		spin_unlock_irqrestore(&sport->port.lock, flags);
121 
122 		mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
123 	}
124 }
125 
126 /*
127  * interrupts disabled on entry
128  */
129 static void sa1100_stop_tx(struct uart_port *port)
130 {
131 	struct sa1100_port *sport =
132 		container_of(port, struct sa1100_port, port);
133 	u32 utcr3;
134 
135 	utcr3 = UART_GET_UTCR3(sport);
136 	UART_PUT_UTCR3(sport, utcr3 & ~UTCR3_TIE);
137 	sport->port.read_status_mask &= ~UTSR0_TO_SM(UTSR0_TFS);
138 }
139 
140 /*
141  * port locked and interrupts disabled
142  */
143 static void sa1100_start_tx(struct uart_port *port)
144 {
145 	struct sa1100_port *sport =
146 		container_of(port, struct sa1100_port, port);
147 	u32 utcr3;
148 
149 	utcr3 = UART_GET_UTCR3(sport);
150 	sport->port.read_status_mask |= UTSR0_TO_SM(UTSR0_TFS);
151 	UART_PUT_UTCR3(sport, utcr3 | UTCR3_TIE);
152 }
153 
154 /*
155  * Interrupts enabled
156  */
157 static void sa1100_stop_rx(struct uart_port *port)
158 {
159 	struct sa1100_port *sport =
160 		container_of(port, struct sa1100_port, port);
161 	u32 utcr3;
162 
163 	utcr3 = UART_GET_UTCR3(sport);
164 	UART_PUT_UTCR3(sport, utcr3 & ~UTCR3_RIE);
165 }
166 
167 /*
168  * Set the modem control timer to fire immediately.
169  */
170 static void sa1100_enable_ms(struct uart_port *port)
171 {
172 	struct sa1100_port *sport =
173 		container_of(port, struct sa1100_port, port);
174 
175 	mod_timer(&sport->timer, jiffies);
176 
177 	mctrl_gpio_enable_ms(sport->gpios);
178 }
179 
180 static void
181 sa1100_rx_chars(struct sa1100_port *sport)
182 {
183 	unsigned int status;
184 	u8 ch, flg;
185 
186 	status = UTSR1_TO_SM(UART_GET_UTSR1(sport)) |
187 		 UTSR0_TO_SM(UART_GET_UTSR0(sport));
188 	while (status & UTSR1_TO_SM(UTSR1_RNE)) {
189 		ch = UART_GET_CHAR(sport);
190 
191 		sport->port.icount.rx++;
192 
193 		flg = TTY_NORMAL;
194 
195 		/*
196 		 * note that the error handling code is
197 		 * out of the main execution path
198 		 */
199 		if (status & UTSR1_TO_SM(UTSR1_PRE | UTSR1_FRE | UTSR1_ROR)) {
200 			if (status & UTSR1_TO_SM(UTSR1_PRE))
201 				sport->port.icount.parity++;
202 			else if (status & UTSR1_TO_SM(UTSR1_FRE))
203 				sport->port.icount.frame++;
204 			if (status & UTSR1_TO_SM(UTSR1_ROR))
205 				sport->port.icount.overrun++;
206 
207 			status &= sport->port.read_status_mask;
208 
209 			if (status & UTSR1_TO_SM(UTSR1_PRE))
210 				flg = TTY_PARITY;
211 			else if (status & UTSR1_TO_SM(UTSR1_FRE))
212 				flg = TTY_FRAME;
213 
214 			sport->port.sysrq = 0;
215 		}
216 
217 		if (uart_handle_sysrq_char(&sport->port, ch))
218 			goto ignore_char;
219 
220 		uart_insert_char(&sport->port, status, UTSR1_TO_SM(UTSR1_ROR), ch, flg);
221 
222 	ignore_char:
223 		status = UTSR1_TO_SM(UART_GET_UTSR1(sport)) |
224 			 UTSR0_TO_SM(UART_GET_UTSR0(sport));
225 	}
226 
227 	tty_flip_buffer_push(&sport->port.state->port);
228 }
229 
230 static void sa1100_tx_chars(struct sa1100_port *sport)
231 {
232 	u8 ch;
233 
234 	/*
235 	 * Check the modem control lines before
236 	 * transmitting anything.
237 	 */
238 	sa1100_mctrl_check(sport);
239 
240 	uart_port_tx(&sport->port, ch,
241 			UART_GET_UTSR1(sport) & UTSR1_TNF,
242 			UART_PUT_CHAR(sport, ch));
243 }
244 
245 static irqreturn_t sa1100_int(int irq, void *dev_id)
246 {
247 	struct sa1100_port *sport = dev_id;
248 	unsigned int status, pass_counter = 0;
249 
250 	spin_lock(&sport->port.lock);
251 	status = UART_GET_UTSR0(sport);
252 	status &= SM_TO_UTSR0(sport->port.read_status_mask) | ~UTSR0_TFS;
253 	do {
254 		if (status & (UTSR0_RFS | UTSR0_RID)) {
255 			/* Clear the receiver idle bit, if set */
256 			if (status & UTSR0_RID)
257 				UART_PUT_UTSR0(sport, UTSR0_RID);
258 			sa1100_rx_chars(sport);
259 		}
260 
261 		/* Clear the relevant break bits */
262 		if (status & (UTSR0_RBB | UTSR0_REB))
263 			UART_PUT_UTSR0(sport, status & (UTSR0_RBB | UTSR0_REB));
264 
265 		if (status & UTSR0_RBB)
266 			sport->port.icount.brk++;
267 
268 		if (status & UTSR0_REB)
269 			uart_handle_break(&sport->port);
270 
271 		if (status & UTSR0_TFS)
272 			sa1100_tx_chars(sport);
273 		if (pass_counter++ > SA1100_ISR_PASS_LIMIT)
274 			break;
275 		status = UART_GET_UTSR0(sport);
276 		status &= SM_TO_UTSR0(sport->port.read_status_mask) |
277 			  ~UTSR0_TFS;
278 	} while (status & (UTSR0_TFS | UTSR0_RFS | UTSR0_RID));
279 	spin_unlock(&sport->port.lock);
280 
281 	return IRQ_HANDLED;
282 }
283 
284 /*
285  * Return TIOCSER_TEMT when transmitter is not busy.
286  */
287 static unsigned int sa1100_tx_empty(struct uart_port *port)
288 {
289 	struct sa1100_port *sport =
290 		container_of(port, struct sa1100_port, port);
291 
292 	return UART_GET_UTSR1(sport) & UTSR1_TBY ? 0 : TIOCSER_TEMT;
293 }
294 
295 static unsigned int sa1100_get_mctrl(struct uart_port *port)
296 {
297 	struct sa1100_port *sport =
298 		container_of(port, struct sa1100_port, port);
299 	int ret = TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
300 
301 	mctrl_gpio_get(sport->gpios, &ret);
302 
303 	return ret;
304 }
305 
306 static void sa1100_set_mctrl(struct uart_port *port, unsigned int mctrl)
307 {
308 	struct sa1100_port *sport =
309 		container_of(port, struct sa1100_port, port);
310 
311 	mctrl_gpio_set(sport->gpios, mctrl);
312 }
313 
314 /*
315  * Interrupts always disabled.
316  */
317 static void sa1100_break_ctl(struct uart_port *port, int break_state)
318 {
319 	struct sa1100_port *sport =
320 		container_of(port, struct sa1100_port, port);
321 	unsigned long flags;
322 	unsigned int utcr3;
323 
324 	spin_lock_irqsave(&sport->port.lock, flags);
325 	utcr3 = UART_GET_UTCR3(sport);
326 	if (break_state == -1)
327 		utcr3 |= UTCR3_BRK;
328 	else
329 		utcr3 &= ~UTCR3_BRK;
330 	UART_PUT_UTCR3(sport, utcr3);
331 	spin_unlock_irqrestore(&sport->port.lock, flags);
332 }
333 
334 static int sa1100_startup(struct uart_port *port)
335 {
336 	struct sa1100_port *sport =
337 		container_of(port, struct sa1100_port, port);
338 	int retval;
339 
340 	/*
341 	 * Allocate the IRQ
342 	 */
343 	retval = request_irq(sport->port.irq, sa1100_int, 0,
344 			     "sa11x0-uart", sport);
345 	if (retval)
346 		return retval;
347 
348 	/*
349 	 * Finally, clear and enable interrupts
350 	 */
351 	UART_PUT_UTSR0(sport, -1);
352 	UART_PUT_UTCR3(sport, UTCR3_RXE | UTCR3_TXE | UTCR3_RIE);
353 
354 	/*
355 	 * Enable modem status interrupts
356 	 */
357 	spin_lock_irq(&sport->port.lock);
358 	sa1100_enable_ms(&sport->port);
359 	spin_unlock_irq(&sport->port.lock);
360 
361 	return 0;
362 }
363 
364 static void sa1100_shutdown(struct uart_port *port)
365 {
366 	struct sa1100_port *sport =
367 		container_of(port, struct sa1100_port, port);
368 
369 	/*
370 	 * Stop our timer.
371 	 */
372 	del_timer_sync(&sport->timer);
373 
374 	/*
375 	 * Free the interrupt
376 	 */
377 	free_irq(sport->port.irq, sport);
378 
379 	/*
380 	 * Disable all interrupts, port and break condition.
381 	 */
382 	UART_PUT_UTCR3(sport, 0);
383 }
384 
385 static void
386 sa1100_set_termios(struct uart_port *port, struct ktermios *termios,
387 		   const struct ktermios *old)
388 {
389 	struct sa1100_port *sport =
390 		container_of(port, struct sa1100_port, port);
391 	unsigned long flags;
392 	unsigned int utcr0, old_utcr3, baud, quot;
393 	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
394 
395 	/*
396 	 * We only support CS7 and CS8.
397 	 */
398 	while ((termios->c_cflag & CSIZE) != CS7 &&
399 	       (termios->c_cflag & CSIZE) != CS8) {
400 		termios->c_cflag &= ~CSIZE;
401 		termios->c_cflag |= old_csize;
402 		old_csize = CS8;
403 	}
404 
405 	if ((termios->c_cflag & CSIZE) == CS8)
406 		utcr0 = UTCR0_DSS;
407 	else
408 		utcr0 = 0;
409 
410 	if (termios->c_cflag & CSTOPB)
411 		utcr0 |= UTCR0_SBS;
412 	if (termios->c_cflag & PARENB) {
413 		utcr0 |= UTCR0_PE;
414 		if (!(termios->c_cflag & PARODD))
415 			utcr0 |= UTCR0_OES;
416 	}
417 
418 	/*
419 	 * Ask the core to calculate the divisor for us.
420 	 */
421 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
422 	quot = uart_get_divisor(port, baud);
423 
424 	del_timer_sync(&sport->timer);
425 
426 	spin_lock_irqsave(&sport->port.lock, flags);
427 
428 	sport->port.read_status_mask &= UTSR0_TO_SM(UTSR0_TFS);
429 	sport->port.read_status_mask |= UTSR1_TO_SM(UTSR1_ROR);
430 	if (termios->c_iflag & INPCK)
431 		sport->port.read_status_mask |=
432 				UTSR1_TO_SM(UTSR1_FRE | UTSR1_PRE);
433 	if (termios->c_iflag & (BRKINT | PARMRK))
434 		sport->port.read_status_mask |=
435 				UTSR0_TO_SM(UTSR0_RBB | UTSR0_REB);
436 
437 	/*
438 	 * Characters to ignore
439 	 */
440 	sport->port.ignore_status_mask = 0;
441 	if (termios->c_iflag & IGNPAR)
442 		sport->port.ignore_status_mask |=
443 				UTSR1_TO_SM(UTSR1_FRE | UTSR1_PRE);
444 	if (termios->c_iflag & IGNBRK) {
445 		sport->port.ignore_status_mask |=
446 				UTSR0_TO_SM(UTSR0_RBB | UTSR0_REB);
447 		/*
448 		 * If we're ignoring parity and break indicators,
449 		 * ignore overruns too (for real raw support).
450 		 */
451 		if (termios->c_iflag & IGNPAR)
452 			sport->port.ignore_status_mask |=
453 				UTSR1_TO_SM(UTSR1_ROR);
454 	}
455 
456 	/*
457 	 * Update the per-port timeout.
458 	 */
459 	uart_update_timeout(port, termios->c_cflag, baud);
460 
461 	/*
462 	 * disable interrupts and drain transmitter
463 	 */
464 	old_utcr3 = UART_GET_UTCR3(sport);
465 	UART_PUT_UTCR3(sport, old_utcr3 & ~(UTCR3_RIE | UTCR3_TIE));
466 
467 	while (UART_GET_UTSR1(sport) & UTSR1_TBY)
468 		barrier();
469 
470 	/* then, disable everything */
471 	UART_PUT_UTCR3(sport, 0);
472 
473 	/* set the parity, stop bits and data size */
474 	UART_PUT_UTCR0(sport, utcr0);
475 
476 	/* set the baud rate */
477 	quot -= 1;
478 	UART_PUT_UTCR1(sport, ((quot & 0xf00) >> 8));
479 	UART_PUT_UTCR2(sport, (quot & 0xff));
480 
481 	UART_PUT_UTSR0(sport, -1);
482 
483 	UART_PUT_UTCR3(sport, old_utcr3);
484 
485 	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
486 		sa1100_enable_ms(&sport->port);
487 
488 	spin_unlock_irqrestore(&sport->port.lock, flags);
489 }
490 
491 static const char *sa1100_type(struct uart_port *port)
492 {
493 	struct sa1100_port *sport =
494 		container_of(port, struct sa1100_port, port);
495 
496 	return sport->port.type == PORT_SA1100 ? "SA1100" : NULL;
497 }
498 
499 /*
500  * Release the memory region(s) being used by 'port'.
501  */
502 static void sa1100_release_port(struct uart_port *port)
503 {
504 	struct sa1100_port *sport =
505 		container_of(port, struct sa1100_port, port);
506 
507 	release_mem_region(sport->port.mapbase, UART_PORT_SIZE);
508 }
509 
510 /*
511  * Request the memory region(s) being used by 'port'.
512  */
513 static int sa1100_request_port(struct uart_port *port)
514 {
515 	struct sa1100_port *sport =
516 		container_of(port, struct sa1100_port, port);
517 
518 	return request_mem_region(sport->port.mapbase, UART_PORT_SIZE,
519 			"sa11x0-uart") != NULL ? 0 : -EBUSY;
520 }
521 
522 /*
523  * Configure/autoconfigure the port.
524  */
525 static void sa1100_config_port(struct uart_port *port, int flags)
526 {
527 	struct sa1100_port *sport =
528 		container_of(port, struct sa1100_port, port);
529 
530 	if (flags & UART_CONFIG_TYPE &&
531 	    sa1100_request_port(&sport->port) == 0)
532 		sport->port.type = PORT_SA1100;
533 }
534 
535 /*
536  * Verify the new serial_struct (for TIOCSSERIAL).
537  * The only change we allow are to the flags and type, and
538  * even then only between PORT_SA1100 and PORT_UNKNOWN
539  */
540 static int
541 sa1100_verify_port(struct uart_port *port, struct serial_struct *ser)
542 {
543 	struct sa1100_port *sport =
544 		container_of(port, struct sa1100_port, port);
545 	int ret = 0;
546 
547 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_SA1100)
548 		ret = -EINVAL;
549 	if (sport->port.irq != ser->irq)
550 		ret = -EINVAL;
551 	if (ser->io_type != SERIAL_IO_MEM)
552 		ret = -EINVAL;
553 	if (sport->port.uartclk / 16 != ser->baud_base)
554 		ret = -EINVAL;
555 	if ((void *)sport->port.mapbase != ser->iomem_base)
556 		ret = -EINVAL;
557 	if (sport->port.iobase != ser->port)
558 		ret = -EINVAL;
559 	if (ser->hub6 != 0)
560 		ret = -EINVAL;
561 	return ret;
562 }
563 
564 static struct uart_ops sa1100_pops = {
565 	.tx_empty	= sa1100_tx_empty,
566 	.set_mctrl	= sa1100_set_mctrl,
567 	.get_mctrl	= sa1100_get_mctrl,
568 	.stop_tx	= sa1100_stop_tx,
569 	.start_tx	= sa1100_start_tx,
570 	.stop_rx	= sa1100_stop_rx,
571 	.enable_ms	= sa1100_enable_ms,
572 	.break_ctl	= sa1100_break_ctl,
573 	.startup	= sa1100_startup,
574 	.shutdown	= sa1100_shutdown,
575 	.set_termios	= sa1100_set_termios,
576 	.type		= sa1100_type,
577 	.release_port	= sa1100_release_port,
578 	.request_port	= sa1100_request_port,
579 	.config_port	= sa1100_config_port,
580 	.verify_port	= sa1100_verify_port,
581 };
582 
583 static struct sa1100_port sa1100_ports[NR_PORTS];
584 
585 /*
586  * Setup the SA1100 serial ports.  Note that we don't include the IrDA
587  * port here since we have our own SIR/FIR driver (see drivers/net/irda)
588  *
589  * Note also that we support "console=ttySAx" where "x" is either 0 or 1.
590  * Which serial port this ends up being depends on the machine you're
591  * running this kernel on.  I'm not convinced that this is a good idea,
592  * but that's the way it traditionally works.
593  *
594  * Note that NanoEngine UART3 becomes UART2, and UART2 is no longer
595  * used here.
596  */
597 static void __init sa1100_init_ports(void)
598 {
599 	static int first = 1;
600 	int i;
601 
602 	if (!first)
603 		return;
604 	first = 0;
605 
606 	for (i = 0; i < NR_PORTS; i++) {
607 		sa1100_ports[i].port.uartclk   = 3686400;
608 		sa1100_ports[i].port.ops       = &sa1100_pops;
609 		sa1100_ports[i].port.fifosize  = 8;
610 		sa1100_ports[i].port.line      = i;
611 		sa1100_ports[i].port.iotype    = UPIO_MEM;
612 		timer_setup(&sa1100_ports[i].timer, sa1100_timeout, 0);
613 	}
614 
615 	/*
616 	 * make transmit lines outputs, so that when the port
617 	 * is closed, the output is in the MARK state.
618 	 */
619 	PPDR |= PPC_TXD1 | PPC_TXD3;
620 	PPSR |= PPC_TXD1 | PPC_TXD3;
621 }
622 
623 void sa1100_register_uart_fns(struct sa1100_port_fns *fns)
624 {
625 	if (fns->get_mctrl)
626 		sa1100_pops.get_mctrl = fns->get_mctrl;
627 	if (fns->set_mctrl)
628 		sa1100_pops.set_mctrl = fns->set_mctrl;
629 
630 	sa1100_pops.pm       = fns->pm;
631 	/*
632 	 * FIXME: fns->set_wake is unused - this should be called from
633 	 * the suspend() callback if device_may_wakeup(dev)) is set.
634 	 */
635 }
636 
637 void __init sa1100_register_uart(int idx, int port)
638 {
639 	if (idx >= NR_PORTS) {
640 		printk(KERN_ERR "%s: bad index number %d\n", __func__, idx);
641 		return;
642 	}
643 
644 	switch (port) {
645 	case 1:
646 		sa1100_ports[idx].port.membase = (void __iomem *)&Ser1UTCR0;
647 		sa1100_ports[idx].port.mapbase = _Ser1UTCR0;
648 		sa1100_ports[idx].port.irq     = IRQ_Ser1UART;
649 		sa1100_ports[idx].port.flags   = UPF_BOOT_AUTOCONF;
650 		break;
651 
652 	case 2:
653 		sa1100_ports[idx].port.membase = (void __iomem *)&Ser2UTCR0;
654 		sa1100_ports[idx].port.mapbase = _Ser2UTCR0;
655 		sa1100_ports[idx].port.irq     = IRQ_Ser2ICP;
656 		sa1100_ports[idx].port.flags   = UPF_BOOT_AUTOCONF;
657 		break;
658 
659 	case 3:
660 		sa1100_ports[idx].port.membase = (void __iomem *)&Ser3UTCR0;
661 		sa1100_ports[idx].port.mapbase = _Ser3UTCR0;
662 		sa1100_ports[idx].port.irq     = IRQ_Ser3UART;
663 		sa1100_ports[idx].port.flags   = UPF_BOOT_AUTOCONF;
664 		break;
665 
666 	default:
667 		printk(KERN_ERR "%s: bad port number %d\n", __func__, port);
668 	}
669 }
670 
671 
672 #ifdef CONFIG_SERIAL_SA1100_CONSOLE
673 static void sa1100_console_putchar(struct uart_port *port, unsigned char ch)
674 {
675 	struct sa1100_port *sport =
676 		container_of(port, struct sa1100_port, port);
677 
678 	while (!(UART_GET_UTSR1(sport) & UTSR1_TNF))
679 		barrier();
680 	UART_PUT_CHAR(sport, ch);
681 }
682 
683 /*
684  * Interrupts are disabled on entering
685  */
686 static void
687 sa1100_console_write(struct console *co, const char *s, unsigned int count)
688 {
689 	struct sa1100_port *sport = &sa1100_ports[co->index];
690 	unsigned int old_utcr3, status;
691 
692 	/*
693 	 *	First, save UTCR3 and then disable interrupts
694 	 */
695 	old_utcr3 = UART_GET_UTCR3(sport);
696 	UART_PUT_UTCR3(sport, (old_utcr3 & ~(UTCR3_RIE | UTCR3_TIE)) |
697 				UTCR3_TXE);
698 
699 	uart_console_write(&sport->port, s, count, sa1100_console_putchar);
700 
701 	/*
702 	 *	Finally, wait for transmitter to become empty
703 	 *	and restore UTCR3
704 	 */
705 	do {
706 		status = UART_GET_UTSR1(sport);
707 	} while (status & UTSR1_TBY);
708 	UART_PUT_UTCR3(sport, old_utcr3);
709 }
710 
711 /*
712  * If the port was already initialised (eg, by a boot loader),
713  * try to determine the current setup.
714  */
715 static void __init
716 sa1100_console_get_options(struct sa1100_port *sport, int *baud,
717 			   int *parity, int *bits)
718 {
719 	unsigned int utcr3;
720 
721 	utcr3 = UART_GET_UTCR3(sport) & (UTCR3_RXE | UTCR3_TXE);
722 	if (utcr3 == (UTCR3_RXE | UTCR3_TXE)) {
723 		/* ok, the port was enabled */
724 		unsigned int utcr0, quot;
725 
726 		utcr0 = UART_GET_UTCR0(sport);
727 
728 		*parity = 'n';
729 		if (utcr0 & UTCR0_PE) {
730 			if (utcr0 & UTCR0_OES)
731 				*parity = 'e';
732 			else
733 				*parity = 'o';
734 		}
735 
736 		if (utcr0 & UTCR0_DSS)
737 			*bits = 8;
738 		else
739 			*bits = 7;
740 
741 		quot = UART_GET_UTCR2(sport) | UART_GET_UTCR1(sport) << 8;
742 		quot &= 0xfff;
743 		*baud = sport->port.uartclk / (16 * (quot + 1));
744 	}
745 }
746 
747 static int __init
748 sa1100_console_setup(struct console *co, char *options)
749 {
750 	struct sa1100_port *sport;
751 	int baud = 9600;
752 	int bits = 8;
753 	int parity = 'n';
754 	int flow = 'n';
755 
756 	/*
757 	 * Check whether an invalid uart number has been specified, and
758 	 * if so, search for the first available port that does have
759 	 * console support.
760 	 */
761 	if (co->index == -1 || co->index >= NR_PORTS)
762 		co->index = 0;
763 	sport = &sa1100_ports[co->index];
764 
765 	if (options)
766 		uart_parse_options(options, &baud, &parity, &bits, &flow);
767 	else
768 		sa1100_console_get_options(sport, &baud, &parity, &bits);
769 
770 	return uart_set_options(&sport->port, co, baud, parity, bits, flow);
771 }
772 
773 static struct uart_driver sa1100_reg;
774 static struct console sa1100_console = {
775 	.name		= "ttySA",
776 	.write		= sa1100_console_write,
777 	.device		= uart_console_device,
778 	.setup		= sa1100_console_setup,
779 	.flags		= CON_PRINTBUFFER,
780 	.index		= -1,
781 	.data		= &sa1100_reg,
782 };
783 
784 static int __init sa1100_rs_console_init(void)
785 {
786 	sa1100_init_ports();
787 	register_console(&sa1100_console);
788 	return 0;
789 }
790 console_initcall(sa1100_rs_console_init);
791 
792 #define SA1100_CONSOLE	&sa1100_console
793 #else
794 #define SA1100_CONSOLE	NULL
795 #endif
796 
797 static struct uart_driver sa1100_reg = {
798 	.owner			= THIS_MODULE,
799 	.driver_name		= "ttySA",
800 	.dev_name		= "ttySA",
801 	.major			= SERIAL_SA1100_MAJOR,
802 	.minor			= MINOR_START,
803 	.nr			= NR_PORTS,
804 	.cons			= SA1100_CONSOLE,
805 };
806 
807 static int sa1100_serial_suspend(struct platform_device *dev, pm_message_t state)
808 {
809 	struct sa1100_port *sport = platform_get_drvdata(dev);
810 
811 	if (sport)
812 		uart_suspend_port(&sa1100_reg, &sport->port);
813 
814 	return 0;
815 }
816 
817 static int sa1100_serial_resume(struct platform_device *dev)
818 {
819 	struct sa1100_port *sport = platform_get_drvdata(dev);
820 
821 	if (sport)
822 		uart_resume_port(&sa1100_reg, &sport->port);
823 
824 	return 0;
825 }
826 
827 static int sa1100_serial_add_one_port(struct sa1100_port *sport, struct platform_device *dev)
828 {
829 	sport->port.dev = &dev->dev;
830 	sport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SA1100_CONSOLE);
831 
832 	// mctrl_gpio_init() requires that the GPIO driver supports interrupts,
833 	// but we need to support GPIO drivers for hardware that has no such
834 	// interrupts.  Use mctrl_gpio_init_noauto() instead.
835 	sport->gpios = mctrl_gpio_init_noauto(sport->port.dev, 0);
836 	if (IS_ERR(sport->gpios)) {
837 		int err = PTR_ERR(sport->gpios);
838 
839 		dev_err(sport->port.dev, "failed to get mctrl gpios: %d\n",
840 			err);
841 
842 		if (err == -EPROBE_DEFER)
843 			return err;
844 
845 		sport->gpios = NULL;
846 	}
847 
848 	platform_set_drvdata(dev, sport);
849 
850 	return uart_add_one_port(&sa1100_reg, &sport->port);
851 }
852 
853 static int sa1100_serial_probe(struct platform_device *dev)
854 {
855 	struct resource *res;
856 	int i;
857 
858 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
859 	if (!res)
860 		return -EINVAL;
861 
862 	for (i = 0; i < NR_PORTS; i++)
863 		if (sa1100_ports[i].port.mapbase == res->start)
864 			break;
865 	if (i == NR_PORTS)
866 		return -ENODEV;
867 
868 	sa1100_serial_add_one_port(&sa1100_ports[i], dev);
869 
870 	return 0;
871 }
872 
873 static int sa1100_serial_remove(struct platform_device *pdev)
874 {
875 	struct sa1100_port *sport = platform_get_drvdata(pdev);
876 
877 	if (sport)
878 		uart_remove_one_port(&sa1100_reg, &sport->port);
879 
880 	return 0;
881 }
882 
883 static struct platform_driver sa11x0_serial_driver = {
884 	.probe		= sa1100_serial_probe,
885 	.remove		= sa1100_serial_remove,
886 	.suspend	= sa1100_serial_suspend,
887 	.resume		= sa1100_serial_resume,
888 	.driver		= {
889 		.name	= "sa11x0-uart",
890 	},
891 };
892 
893 static int __init sa1100_serial_init(void)
894 {
895 	int ret;
896 
897 	printk(KERN_INFO "Serial: SA11x0 driver\n");
898 
899 	sa1100_init_ports();
900 
901 	ret = uart_register_driver(&sa1100_reg);
902 	if (ret == 0) {
903 		ret = platform_driver_register(&sa11x0_serial_driver);
904 		if (ret)
905 			uart_unregister_driver(&sa1100_reg);
906 	}
907 	return ret;
908 }
909 
910 static void __exit sa1100_serial_exit(void)
911 {
912 	platform_driver_unregister(&sa11x0_serial_driver);
913 	uart_unregister_driver(&sa1100_reg);
914 }
915 
916 module_init(sa1100_serial_init);
917 module_exit(sa1100_serial_exit);
918 
919 MODULE_AUTHOR("Deep Blue Solutions Ltd");
920 MODULE_DESCRIPTION("SA1100 generic serial port driver");
921 MODULE_LICENSE("GPL");
922 MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_SA1100_MAJOR);
923 MODULE_ALIAS("platform:sa11x0-uart");
924