1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  Universal/legacy driver for 8250/16550-type serial ports
4  *
5  *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6  *
7  *  Copyright (C) 2001 Russell King.
8  *
9  *  Supports: ISA-compatible 8250/16550 ports
10  *	      PNP 8250/16550 ports
11  *	      early_serial_setup() ports
12  *	      userspace-configurable "phantom" ports
13  *	      "serial8250" platform devices
14  *	      serial8250_register_8250_port() ports
15  */
16 
17 #include <linux/acpi.h>
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/ioport.h>
21 #include <linux/init.h>
22 #include <linux/console.h>
23 #include <linux/sysrq.h>
24 #include <linux/delay.h>
25 #include <linux/platform_device.h>
26 #include <linux/pm_runtime.h>
27 #include <linux/tty.h>
28 #include <linux/ratelimit.h>
29 #include <linux/tty_flip.h>
30 #include <linux/serial.h>
31 #include <linux/serial_8250.h>
32 #include <linux/nmi.h>
33 #include <linux/mutex.h>
34 #include <linux/slab.h>
35 #include <linux/string_helpers.h>
36 #include <linux/uaccess.h>
37 #include <linux/io.h>
38 #ifdef CONFIG_SPARC
39 #include <linux/sunserialcore.h>
40 #endif
41 
42 #include <asm/irq.h>
43 
44 #include "8250.h"
45 
46 /*
47  * Configuration:
48  *   share_irqs - whether we pass IRQF_SHARED to request_irq().  This option
49  *                is unsafe when used on edge-triggered interrupts.
50  */
51 static unsigned int share_irqs = SERIAL8250_SHARE_IRQS;
52 
53 static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;
54 
55 static struct uart_driver serial8250_reg;
56 
57 static unsigned int skip_txen_test; /* force skip of txen test at init time */
58 
59 #define PASS_LIMIT	512
60 
61 #include <asm/serial.h>
62 /*
63  * SERIAL_PORT_DFNS tells us about built-in ports that have no
64  * standard enumeration mechanism.   Platforms that can find all
65  * serial ports via mechanisms like ACPI or PCI need not supply it.
66  */
67 #ifndef SERIAL_PORT_DFNS
68 #define SERIAL_PORT_DFNS
69 #endif
70 
71 static const struct old_serial_port old_serial_port[] = {
72 	SERIAL_PORT_DFNS /* defined in asm/serial.h */
73 };
74 
75 #define UART_NR	CONFIG_SERIAL_8250_NR_UARTS
76 
77 #ifdef CONFIG_SERIAL_8250_RSA
78 
79 #define PORT_RSA_MAX 4
80 static unsigned long probe_rsa[PORT_RSA_MAX];
81 static unsigned int probe_rsa_count;
82 #endif /* CONFIG_SERIAL_8250_RSA  */
83 
84 struct irq_info {
85 	struct			hlist_node node;
86 	int			irq;
87 	spinlock_t		lock;	/* Protects list not the hash */
88 	struct list_head	*head;
89 };
90 
91 #define NR_IRQ_HASH		32	/* Can be adjusted later */
92 static struct hlist_head irq_lists[NR_IRQ_HASH];
93 static DEFINE_MUTEX(hash_mutex);	/* Used to walk the hash */
94 
95 /*
96  * This is the serial driver's interrupt routine.
97  *
98  * Arjan thinks the old way was overly complex, so it got simplified.
99  * Alan disagrees, saying that need the complexity to handle the weird
100  * nature of ISA shared interrupts.  (This is a special exception.)
101  *
102  * In order to handle ISA shared interrupts properly, we need to check
103  * that all ports have been serviced, and therefore the ISA interrupt
104  * line has been de-asserted.
105  *
106  * This means we need to loop through all ports. checking that they
107  * don't have an interrupt pending.
108  */
serial8250_interrupt(int irq,void * dev_id)109 static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
110 {
111 	struct irq_info *i = dev_id;
112 	struct list_head *l, *end = NULL;
113 	int pass_counter = 0, handled = 0;
114 
115 	pr_debug("%s(%d): start\n", __func__, irq);
116 
117 	spin_lock(&i->lock);
118 
119 	l = i->head;
120 	do {
121 		struct uart_8250_port *up;
122 		struct uart_port *port;
123 
124 		up = list_entry(l, struct uart_8250_port, list);
125 		port = &up->port;
126 
127 		if (port->handle_irq(port)) {
128 			handled = 1;
129 			end = NULL;
130 		} else if (end == NULL)
131 			end = l;
132 
133 		l = l->next;
134 
135 		if (l == i->head && pass_counter++ > PASS_LIMIT)
136 			break;
137 	} while (l != end);
138 
139 	spin_unlock(&i->lock);
140 
141 	pr_debug("%s(%d): end\n", __func__, irq);
142 
143 	return IRQ_RETVAL(handled);
144 }
145 
146 /*
147  * To support ISA shared interrupts, we need to have one interrupt
148  * handler that ensures that the IRQ line has been deasserted
149  * before returning.  Failing to do this will result in the IRQ
150  * line being stuck active, and, since ISA irqs are edge triggered,
151  * no more IRQs will be seen.
152  */
serial_do_unlink(struct irq_info * i,struct uart_8250_port * up)153 static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up)
154 {
155 	spin_lock_irq(&i->lock);
156 
157 	if (!list_empty(i->head)) {
158 		if (i->head == &up->list)
159 			i->head = i->head->next;
160 		list_del(&up->list);
161 	} else {
162 		BUG_ON(i->head != &up->list);
163 		i->head = NULL;
164 	}
165 	spin_unlock_irq(&i->lock);
166 	/* List empty so throw away the hash node */
167 	if (i->head == NULL) {
168 		hlist_del(&i->node);
169 		kfree(i);
170 	}
171 }
172 
serial_link_irq_chain(struct uart_8250_port * up)173 static int serial_link_irq_chain(struct uart_8250_port *up)
174 {
175 	struct hlist_head *h;
176 	struct irq_info *i;
177 	int ret;
178 
179 	mutex_lock(&hash_mutex);
180 
181 	h = &irq_lists[up->port.irq % NR_IRQ_HASH];
182 
183 	hlist_for_each_entry(i, h, node)
184 		if (i->irq == up->port.irq)
185 			break;
186 
187 	if (i == NULL) {
188 		i = kzalloc(sizeof(struct irq_info), GFP_KERNEL);
189 		if (i == NULL) {
190 			mutex_unlock(&hash_mutex);
191 			return -ENOMEM;
192 		}
193 		spin_lock_init(&i->lock);
194 		i->irq = up->port.irq;
195 		hlist_add_head(&i->node, h);
196 	}
197 	mutex_unlock(&hash_mutex);
198 
199 	spin_lock_irq(&i->lock);
200 
201 	if (i->head) {
202 		list_add(&up->list, i->head);
203 		spin_unlock_irq(&i->lock);
204 
205 		ret = 0;
206 	} else {
207 		INIT_LIST_HEAD(&up->list);
208 		i->head = &up->list;
209 		spin_unlock_irq(&i->lock);
210 		ret = request_irq(up->port.irq, serial8250_interrupt,
211 				  up->port.irqflags, up->port.name, i);
212 		if (ret < 0)
213 			serial_do_unlink(i, up);
214 	}
215 
216 	return ret;
217 }
218 
serial_unlink_irq_chain(struct uart_8250_port * up)219 static void serial_unlink_irq_chain(struct uart_8250_port *up)
220 {
221 	struct irq_info *i;
222 	struct hlist_head *h;
223 
224 	mutex_lock(&hash_mutex);
225 
226 	h = &irq_lists[up->port.irq % NR_IRQ_HASH];
227 
228 	hlist_for_each_entry(i, h, node)
229 		if (i->irq == up->port.irq)
230 			break;
231 
232 	BUG_ON(i == NULL);
233 	BUG_ON(i->head == NULL);
234 
235 	if (list_empty(i->head))
236 		free_irq(up->port.irq, i);
237 
238 	serial_do_unlink(i, up);
239 	mutex_unlock(&hash_mutex);
240 }
241 
242 /*
243  * This function is used to handle ports that do not have an
244  * interrupt.  This doesn't work very well for 16450's, but gives
245  * barely passable results for a 16550A.  (Although at the expense
246  * of much CPU overhead).
247  */
serial8250_timeout(struct timer_list * t)248 static void serial8250_timeout(struct timer_list *t)
249 {
250 	struct uart_8250_port *up = from_timer(up, t, timer);
251 
252 	up->port.handle_irq(&up->port);
253 	mod_timer(&up->timer, jiffies + uart_poll_timeout(&up->port));
254 }
255 
serial8250_backup_timeout(struct timer_list * t)256 static void serial8250_backup_timeout(struct timer_list *t)
257 {
258 	struct uart_8250_port *up = from_timer(up, t, timer);
259 	unsigned int iir, ier = 0, lsr;
260 	unsigned long flags;
261 
262 	spin_lock_irqsave(&up->port.lock, flags);
263 
264 	/*
265 	 * Must disable interrupts or else we risk racing with the interrupt
266 	 * based handler.
267 	 */
268 	if (up->port.irq) {
269 		ier = serial_in(up, UART_IER);
270 		serial_out(up, UART_IER, 0);
271 	}
272 
273 	iir = serial_in(up, UART_IIR);
274 
275 	/*
276 	 * This should be a safe test for anyone who doesn't trust the
277 	 * IIR bits on their UART, but it's specifically designed for
278 	 * the "Diva" UART used on the management processor on many HP
279 	 * ia64 and parisc boxes.
280 	 */
281 	lsr = serial_lsr_in(up);
282 	if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) &&
283 	    (!uart_circ_empty(&up->port.state->xmit) || up->port.x_char) &&
284 	    (lsr & UART_LSR_THRE)) {
285 		iir &= ~(UART_IIR_ID | UART_IIR_NO_INT);
286 		iir |= UART_IIR_THRI;
287 	}
288 
289 	if (!(iir & UART_IIR_NO_INT))
290 		serial8250_tx_chars(up);
291 
292 	if (up->port.irq)
293 		serial_out(up, UART_IER, ier);
294 
295 	spin_unlock_irqrestore(&up->port.lock, flags);
296 
297 	/* Standard timer interval plus 0.2s to keep the port running */
298 	mod_timer(&up->timer,
299 		jiffies + uart_poll_timeout(&up->port) + HZ / 5);
300 }
301 
univ8250_setup_timer(struct uart_8250_port * up)302 static void univ8250_setup_timer(struct uart_8250_port *up)
303 {
304 	struct uart_port *port = &up->port;
305 
306 	/*
307 	 * The above check will only give an accurate result the first time
308 	 * the port is opened so this value needs to be preserved.
309 	 */
310 	if (up->bugs & UART_BUG_THRE) {
311 		pr_debug("%s - using backup timer\n", port->name);
312 
313 		up->timer.function = serial8250_backup_timeout;
314 		mod_timer(&up->timer, jiffies +
315 			  uart_poll_timeout(port) + HZ / 5);
316 	}
317 
318 	/*
319 	 * If the "interrupt" for this port doesn't correspond with any
320 	 * hardware interrupt, we use a timer-based system.  The original
321 	 * driver used to do this with IRQ0.
322 	 */
323 	if (!port->irq)
324 		mod_timer(&up->timer, jiffies + uart_poll_timeout(port));
325 }
326 
univ8250_setup_irq(struct uart_8250_port * up)327 static int univ8250_setup_irq(struct uart_8250_port *up)
328 {
329 	struct uart_port *port = &up->port;
330 
331 	if (port->irq)
332 		return serial_link_irq_chain(up);
333 
334 	return 0;
335 }
336 
univ8250_release_irq(struct uart_8250_port * up)337 static void univ8250_release_irq(struct uart_8250_port *up)
338 {
339 	struct uart_port *port = &up->port;
340 
341 	del_timer_sync(&up->timer);
342 	up->timer.function = serial8250_timeout;
343 	if (port->irq)
344 		serial_unlink_irq_chain(up);
345 }
346 
347 #ifdef CONFIG_SERIAL_8250_RSA
serial8250_request_rsa_resource(struct uart_8250_port * up)348 static int serial8250_request_rsa_resource(struct uart_8250_port *up)
349 {
350 	unsigned long start = UART_RSA_BASE << up->port.regshift;
351 	unsigned int size = 8 << up->port.regshift;
352 	struct uart_port *port = &up->port;
353 	int ret = -EINVAL;
354 
355 	switch (port->iotype) {
356 	case UPIO_HUB6:
357 	case UPIO_PORT:
358 		start += port->iobase;
359 		if (request_region(start, size, "serial-rsa"))
360 			ret = 0;
361 		else
362 			ret = -EBUSY;
363 		break;
364 	}
365 
366 	return ret;
367 }
368 
serial8250_release_rsa_resource(struct uart_8250_port * up)369 static void serial8250_release_rsa_resource(struct uart_8250_port *up)
370 {
371 	unsigned long offset = UART_RSA_BASE << up->port.regshift;
372 	unsigned int size = 8 << up->port.regshift;
373 	struct uart_port *port = &up->port;
374 
375 	switch (port->iotype) {
376 	case UPIO_HUB6:
377 	case UPIO_PORT:
378 		release_region(port->iobase + offset, size);
379 		break;
380 	}
381 }
382 #endif
383 
384 static const struct uart_ops *base_ops;
385 static struct uart_ops univ8250_port_ops;
386 
387 static const struct uart_8250_ops univ8250_driver_ops = {
388 	.setup_irq	= univ8250_setup_irq,
389 	.release_irq	= univ8250_release_irq,
390 	.setup_timer	= univ8250_setup_timer,
391 };
392 
393 static struct uart_8250_port serial8250_ports[UART_NR];
394 
395 /**
396  * serial8250_get_port - retrieve struct uart_8250_port
397  * @line: serial line number
398  *
399  * This function retrieves struct uart_8250_port for the specific line.
400  * This struct *must* *not* be used to perform a 8250 or serial core operation
401  * which is not accessible otherwise. Its only purpose is to make the struct
402  * accessible to the runtime-pm callbacks for context suspend/restore.
403  * The lock assumption made here is none because runtime-pm suspend/resume
404  * callbacks should not be invoked if there is any operation performed on the
405  * port.
406  */
serial8250_get_port(int line)407 struct uart_8250_port *serial8250_get_port(int line)
408 {
409 	return &serial8250_ports[line];
410 }
411 EXPORT_SYMBOL_GPL(serial8250_get_port);
412 
413 static void (*serial8250_isa_config)(int port, struct uart_port *up,
414 	u32 *capabilities);
415 
serial8250_set_isa_configurator(void (* v)(int port,struct uart_port * up,u32 * capabilities))416 void serial8250_set_isa_configurator(
417 	void (*v)(int port, struct uart_port *up, u32 *capabilities))
418 {
419 	serial8250_isa_config = v;
420 }
421 EXPORT_SYMBOL(serial8250_set_isa_configurator);
422 
423 #ifdef CONFIG_SERIAL_8250_RSA
424 
univ8250_config_port(struct uart_port * port,int flags)425 static void univ8250_config_port(struct uart_port *port, int flags)
426 {
427 	struct uart_8250_port *up = up_to_u8250p(port);
428 
429 	up->probe &= ~UART_PROBE_RSA;
430 	if (port->type == PORT_RSA) {
431 		if (serial8250_request_rsa_resource(up) == 0)
432 			up->probe |= UART_PROBE_RSA;
433 	} else if (flags & UART_CONFIG_TYPE) {
434 		int i;
435 
436 		for (i = 0; i < probe_rsa_count; i++) {
437 			if (probe_rsa[i] == up->port.iobase) {
438 				if (serial8250_request_rsa_resource(up) == 0)
439 					up->probe |= UART_PROBE_RSA;
440 				break;
441 			}
442 		}
443 	}
444 
445 	base_ops->config_port(port, flags);
446 
447 	if (port->type != PORT_RSA && up->probe & UART_PROBE_RSA)
448 		serial8250_release_rsa_resource(up);
449 }
450 
univ8250_request_port(struct uart_port * port)451 static int univ8250_request_port(struct uart_port *port)
452 {
453 	struct uart_8250_port *up = up_to_u8250p(port);
454 	int ret;
455 
456 	ret = base_ops->request_port(port);
457 	if (ret == 0 && port->type == PORT_RSA) {
458 		ret = serial8250_request_rsa_resource(up);
459 		if (ret < 0)
460 			base_ops->release_port(port);
461 	}
462 
463 	return ret;
464 }
465 
univ8250_release_port(struct uart_port * port)466 static void univ8250_release_port(struct uart_port *port)
467 {
468 	struct uart_8250_port *up = up_to_u8250p(port);
469 
470 	if (port->type == PORT_RSA)
471 		serial8250_release_rsa_resource(up);
472 	base_ops->release_port(port);
473 }
474 
univ8250_rsa_support(struct uart_ops * ops)475 static void univ8250_rsa_support(struct uart_ops *ops)
476 {
477 	ops->config_port  = univ8250_config_port;
478 	ops->request_port = univ8250_request_port;
479 	ops->release_port = univ8250_release_port;
480 }
481 
482 #else
483 #define univ8250_rsa_support(x)		do { } while (0)
484 #endif /* CONFIG_SERIAL_8250_RSA */
485 
serial8250_apply_quirks(struct uart_8250_port * up)486 static inline void serial8250_apply_quirks(struct uart_8250_port *up)
487 {
488 	up->port.quirks |= skip_txen_test ? UPQ_NO_TXEN_TEST : 0;
489 }
490 
serial8250_setup_port(int index)491 static struct uart_8250_port *serial8250_setup_port(int index)
492 {
493 	struct uart_8250_port *up;
494 
495 	if (index >= UART_NR)
496 		return NULL;
497 
498 	up = &serial8250_ports[index];
499 	up->port.line = index;
500 	up->port.port_id = index;
501 
502 	serial8250_init_port(up);
503 	if (!base_ops)
504 		base_ops = up->port.ops;
505 	up->port.ops = &univ8250_port_ops;
506 
507 	timer_setup(&up->timer, serial8250_timeout, 0);
508 
509 	up->ops = &univ8250_driver_ops;
510 
511 	if (IS_ENABLED(CONFIG_ALPHA_JENSEN) ||
512 	    (IS_ENABLED(CONFIG_ALPHA_GENERIC) && alpha_jensen()))
513 		up->port.set_mctrl = alpha_jensen_set_mctrl;
514 
515 	serial8250_set_defaults(up);
516 
517 	return up;
518 }
519 
serial8250_isa_init_ports(void)520 static void __init serial8250_isa_init_ports(void)
521 {
522 	struct uart_8250_port *up;
523 	static int first = 1;
524 	int i, irqflag = 0;
525 
526 	if (!first)
527 		return;
528 	first = 0;
529 
530 	if (nr_uarts > UART_NR)
531 		nr_uarts = UART_NR;
532 
533 	/*
534 	 * Set up initial isa ports based on nr_uart module param, or else
535 	 * default to CONFIG_SERIAL_8250_RUNTIME_UARTS. Note that we do not
536 	 * need to increase nr_uarts when setting up the initial isa ports.
537 	 */
538 	for (i = 0; i < nr_uarts; i++)
539 		serial8250_setup_port(i);
540 
541 	/* chain base port ops to support Remote Supervisor Adapter */
542 	univ8250_port_ops = *base_ops;
543 	univ8250_rsa_support(&univ8250_port_ops);
544 
545 	if (share_irqs)
546 		irqflag = IRQF_SHARED;
547 
548 	for (i = 0, up = serial8250_ports;
549 	     i < ARRAY_SIZE(old_serial_port) && i < nr_uarts;
550 	     i++, up++) {
551 		struct uart_port *port = &up->port;
552 
553 		port->iobase   = old_serial_port[i].port;
554 		port->irq      = irq_canonicalize(old_serial_port[i].irq);
555 		port->irqflags = 0;
556 		port->uartclk  = old_serial_port[i].baud_base * 16;
557 		port->flags    = old_serial_port[i].flags;
558 		port->hub6     = 0;
559 		port->membase  = old_serial_port[i].iomem_base;
560 		port->iotype   = old_serial_port[i].io_type;
561 		port->regshift = old_serial_port[i].iomem_reg_shift;
562 
563 		port->irqflags |= irqflag;
564 		if (serial8250_isa_config != NULL)
565 			serial8250_isa_config(i, &up->port, &up->capabilities);
566 	}
567 }
568 
569 static void __init
serial8250_register_ports(struct uart_driver * drv,struct device * dev)570 serial8250_register_ports(struct uart_driver *drv, struct device *dev)
571 {
572 	int i;
573 
574 	for (i = 0; i < nr_uarts; i++) {
575 		struct uart_8250_port *up = &serial8250_ports[i];
576 
577 		if (up->port.type == PORT_8250_CIR)
578 			continue;
579 
580 		if (up->port.dev)
581 			continue;
582 
583 		up->port.dev = dev;
584 
585 		if (uart_console_registered(&up->port))
586 			pm_runtime_get_sync(up->port.dev);
587 
588 		serial8250_apply_quirks(up);
589 		uart_add_one_port(drv, &up->port);
590 	}
591 }
592 
593 #ifdef CONFIG_SERIAL_8250_CONSOLE
594 
univ8250_console_write(struct console * co,const char * s,unsigned int count)595 static void univ8250_console_write(struct console *co, const char *s,
596 				   unsigned int count)
597 {
598 	struct uart_8250_port *up = &serial8250_ports[co->index];
599 
600 	serial8250_console_write(up, s, count);
601 }
602 
univ8250_console_setup(struct console * co,char * options)603 static int univ8250_console_setup(struct console *co, char *options)
604 {
605 	struct uart_8250_port *up;
606 	struct uart_port *port;
607 	int retval, i;
608 
609 	/*
610 	 * Check whether an invalid uart number has been specified, and
611 	 * if so, search for the first available port that does have
612 	 * console support.
613 	 */
614 	if (co->index >= UART_NR)
615 		co->index = 0;
616 
617 	/*
618 	 * If the console is past the initial isa ports, init more ports up to
619 	 * co->index as needed and increment nr_uarts accordingly.
620 	 */
621 	for (i = nr_uarts; i <= co->index; i++) {
622 		up = serial8250_setup_port(i);
623 		if (!up)
624 			return -ENODEV;
625 		nr_uarts++;
626 	}
627 
628 	port = &serial8250_ports[co->index].port;
629 	/* link port to console */
630 	port->cons = co;
631 
632 	retval = serial8250_console_setup(port, options, false);
633 	if (retval != 0)
634 		port->cons = NULL;
635 	return retval;
636 }
637 
univ8250_console_exit(struct console * co)638 static int univ8250_console_exit(struct console *co)
639 {
640 	struct uart_port *port;
641 
642 	port = &serial8250_ports[co->index].port;
643 	return serial8250_console_exit(port);
644 }
645 
646 /**
647  *	univ8250_console_match - non-standard console matching
648  *	@co:	  registering console
649  *	@name:	  name from console command line
650  *	@idx:	  index from console command line
651  *	@options: ptr to option string from console command line
652  *
653  *	Only attempts to match console command lines of the form:
654  *	    console=uart[8250],io|mmio|mmio16|mmio32,<addr>[,<options>]
655  *	    console=uart[8250],0x<addr>[,<options>]
656  *	This form is used to register an initial earlycon boot console and
657  *	replace it with the serial8250_console at 8250 driver init.
658  *
659  *	Performs console setup for a match (as required by interface)
660  *	If no <options> are specified, then assume the h/w is already setup.
661  *
662  *	Returns 0 if console matches; otherwise non-zero to use default matching
663  */
univ8250_console_match(struct console * co,char * name,int idx,char * options)664 static int univ8250_console_match(struct console *co, char *name, int idx,
665 				  char *options)
666 {
667 	char match[] = "uart";	/* 8250-specific earlycon name */
668 	unsigned char iotype;
669 	resource_size_t addr;
670 	int i;
671 
672 	if (strncmp(name, match, 4) != 0)
673 		return -ENODEV;
674 
675 	if (uart_parse_earlycon(options, &iotype, &addr, &options))
676 		return -ENODEV;
677 
678 	/* try to match the port specified on the command line */
679 	for (i = 0; i < nr_uarts; i++) {
680 		struct uart_port *port = &serial8250_ports[i].port;
681 
682 		if (port->iotype != iotype)
683 			continue;
684 		if ((iotype == UPIO_MEM || iotype == UPIO_MEM16 ||
685 		     iotype == UPIO_MEM32 || iotype == UPIO_MEM32BE)
686 		    && (port->mapbase != addr))
687 			continue;
688 		if (iotype == UPIO_PORT && port->iobase != addr)
689 			continue;
690 
691 		co->index = i;
692 		port->cons = co;
693 		return serial8250_console_setup(port, options, true);
694 	}
695 
696 	return -ENODEV;
697 }
698 
699 static struct console univ8250_console = {
700 	.name		= "ttyS",
701 	.write		= univ8250_console_write,
702 	.device		= uart_console_device,
703 	.setup		= univ8250_console_setup,
704 	.exit		= univ8250_console_exit,
705 	.match		= univ8250_console_match,
706 	.flags		= CON_PRINTBUFFER | CON_ANYTIME,
707 	.index		= -1,
708 	.data		= &serial8250_reg,
709 };
710 
univ8250_console_init(void)711 static int __init univ8250_console_init(void)
712 {
713 	if (nr_uarts == 0)
714 		return -ENODEV;
715 
716 	serial8250_isa_init_ports();
717 	register_console(&univ8250_console);
718 	return 0;
719 }
720 console_initcall(univ8250_console_init);
721 
722 #define SERIAL8250_CONSOLE	(&univ8250_console)
723 #else
724 #define SERIAL8250_CONSOLE	NULL
725 #endif
726 
727 static struct uart_driver serial8250_reg = {
728 	.owner			= THIS_MODULE,
729 	.driver_name		= "serial",
730 	.dev_name		= "ttyS",
731 	.major			= TTY_MAJOR,
732 	.minor			= 64,
733 	.cons			= SERIAL8250_CONSOLE,
734 };
735 
736 /*
737  * early_serial_setup - early registration for 8250 ports
738  *
739  * Setup an 8250 port structure prior to console initialisation.  Use
740  * after console initialisation will cause undefined behaviour.
741  */
early_serial_setup(struct uart_port * port)742 int __init early_serial_setup(struct uart_port *port)
743 {
744 	struct uart_port *p;
745 
746 	if (port->line >= ARRAY_SIZE(serial8250_ports) || nr_uarts == 0)
747 		return -ENODEV;
748 
749 	serial8250_isa_init_ports();
750 	p = &serial8250_ports[port->line].port;
751 	p->iobase       = port->iobase;
752 	p->membase      = port->membase;
753 	p->irq          = port->irq;
754 	p->irqflags     = port->irqflags;
755 	p->uartclk      = port->uartclk;
756 	p->fifosize     = port->fifosize;
757 	p->regshift     = port->regshift;
758 	p->iotype       = port->iotype;
759 	p->flags        = port->flags;
760 	p->mapbase      = port->mapbase;
761 	p->mapsize      = port->mapsize;
762 	p->private_data = port->private_data;
763 	p->type		= port->type;
764 	p->line		= port->line;
765 
766 	serial8250_set_defaults(up_to_u8250p(p));
767 
768 	if (port->serial_in)
769 		p->serial_in = port->serial_in;
770 	if (port->serial_out)
771 		p->serial_out = port->serial_out;
772 	if (port->handle_irq)
773 		p->handle_irq = port->handle_irq;
774 
775 	return 0;
776 }
777 
778 /**
779  *	serial8250_suspend_port - suspend one serial port
780  *	@line:  serial line number
781  *
782  *	Suspend one serial port.
783  */
serial8250_suspend_port(int line)784 void serial8250_suspend_port(int line)
785 {
786 	struct uart_8250_port *up = &serial8250_ports[line];
787 	struct uart_port *port = &up->port;
788 
789 	if (!console_suspend_enabled && uart_console(port) &&
790 	    port->type != PORT_8250) {
791 		unsigned char canary = 0xa5;
792 
793 		serial_out(up, UART_SCR, canary);
794 		if (serial_in(up, UART_SCR) == canary)
795 			up->canary = canary;
796 	}
797 
798 	uart_suspend_port(&serial8250_reg, port);
799 }
800 EXPORT_SYMBOL(serial8250_suspend_port);
801 
802 /**
803  *	serial8250_resume_port - resume one serial port
804  *	@line:  serial line number
805  *
806  *	Resume one serial port.
807  */
serial8250_resume_port(int line)808 void serial8250_resume_port(int line)
809 {
810 	struct uart_8250_port *up = &serial8250_ports[line];
811 	struct uart_port *port = &up->port;
812 
813 	up->canary = 0;
814 
815 	if (up->capabilities & UART_NATSEMI) {
816 		/* Ensure it's still in high speed mode */
817 		serial_port_out(port, UART_LCR, 0xE0);
818 
819 		ns16550a_goto_highspeed(up);
820 
821 		serial_port_out(port, UART_LCR, 0);
822 		port->uartclk = 921600*16;
823 	}
824 	uart_resume_port(&serial8250_reg, port);
825 }
826 EXPORT_SYMBOL(serial8250_resume_port);
827 
828 /*
829  * Register a set of serial devices attached to a platform device.  The
830  * list is terminated with a zero flags entry, which means we expect
831  * all entries to have at least UPF_BOOT_AUTOCONF set.
832  */
serial8250_probe(struct platform_device * dev)833 static int serial8250_probe(struct platform_device *dev)
834 {
835 	struct plat_serial8250_port *p = dev_get_platdata(&dev->dev);
836 	struct uart_8250_port uart;
837 	int ret, i, irqflag = 0;
838 
839 	memset(&uart, 0, sizeof(uart));
840 
841 	if (share_irqs)
842 		irqflag = IRQF_SHARED;
843 
844 	for (i = 0; p && p->flags != 0; p++, i++) {
845 		uart.port.iobase	= p->iobase;
846 		uart.port.membase	= p->membase;
847 		uart.port.irq		= p->irq;
848 		uart.port.irqflags	= p->irqflags;
849 		uart.port.uartclk	= p->uartclk;
850 		uart.port.regshift	= p->regshift;
851 		uart.port.iotype	= p->iotype;
852 		uart.port.flags		= p->flags;
853 		uart.port.mapbase	= p->mapbase;
854 		uart.port.mapsize	= p->mapsize;
855 		uart.port.hub6		= p->hub6;
856 		uart.port.has_sysrq	= p->has_sysrq;
857 		uart.port.private_data	= p->private_data;
858 		uart.port.type		= p->type;
859 		uart.bugs		= p->bugs;
860 		uart.port.serial_in	= p->serial_in;
861 		uart.port.serial_out	= p->serial_out;
862 		uart.dl_read		= p->dl_read;
863 		uart.dl_write		= p->dl_write;
864 		uart.port.handle_irq	= p->handle_irq;
865 		uart.port.handle_break	= p->handle_break;
866 		uart.port.set_termios	= p->set_termios;
867 		uart.port.set_ldisc	= p->set_ldisc;
868 		uart.port.get_mctrl	= p->get_mctrl;
869 		uart.port.pm		= p->pm;
870 		uart.port.dev		= &dev->dev;
871 		uart.port.irqflags	|= irqflag;
872 		ret = serial8250_register_8250_port(&uart);
873 		if (ret < 0) {
874 			dev_err(&dev->dev, "unable to register port at index %d "
875 				"(IO%lx MEM%llx IRQ%d): %d\n", i,
876 				p->iobase, (unsigned long long)p->mapbase,
877 				p->irq, ret);
878 		}
879 	}
880 	return 0;
881 }
882 
883 /*
884  * Remove serial ports registered against a platform device.
885  */
serial8250_remove(struct platform_device * dev)886 static int serial8250_remove(struct platform_device *dev)
887 {
888 	int i;
889 
890 	for (i = 0; i < nr_uarts; i++) {
891 		struct uart_8250_port *up = &serial8250_ports[i];
892 
893 		if (up->port.dev == &dev->dev)
894 			serial8250_unregister_port(i);
895 	}
896 	return 0;
897 }
898 
serial8250_suspend(struct platform_device * dev,pm_message_t state)899 static int serial8250_suspend(struct platform_device *dev, pm_message_t state)
900 {
901 	int i;
902 
903 	for (i = 0; i < UART_NR; i++) {
904 		struct uart_8250_port *up = &serial8250_ports[i];
905 
906 		if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
907 			uart_suspend_port(&serial8250_reg, &up->port);
908 	}
909 
910 	return 0;
911 }
912 
serial8250_resume(struct platform_device * dev)913 static int serial8250_resume(struct platform_device *dev)
914 {
915 	int i;
916 
917 	for (i = 0; i < UART_NR; i++) {
918 		struct uart_8250_port *up = &serial8250_ports[i];
919 
920 		if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
921 			serial8250_resume_port(i);
922 	}
923 
924 	return 0;
925 }
926 
927 static struct platform_driver serial8250_isa_driver = {
928 	.probe		= serial8250_probe,
929 	.remove		= serial8250_remove,
930 	.suspend	= serial8250_suspend,
931 	.resume		= serial8250_resume,
932 	.driver		= {
933 		.name	= "serial8250",
934 	},
935 };
936 
937 /*
938  * This "device" covers _all_ ISA 8250-compatible serial devices listed
939  * in the table in include/asm/serial.h
940  */
941 static struct platform_device *serial8250_isa_devs;
942 
943 /*
944  * serial8250_register_8250_port and serial8250_unregister_port allows for
945  * 16x50 serial ports to be configured at run-time, to support PCMCIA
946  * modems and PCI multiport cards.
947  */
948 static DEFINE_MUTEX(serial_mutex);
949 
serial8250_find_match_or_unused(const struct uart_port * port)950 static struct uart_8250_port *serial8250_find_match_or_unused(const struct uart_port *port)
951 {
952 	int i;
953 
954 	/*
955 	 * First, find a port entry which matches.
956 	 */
957 	for (i = 0; i < nr_uarts; i++)
958 		if (uart_match_port(&serial8250_ports[i].port, port))
959 			return &serial8250_ports[i];
960 
961 	/* try line number first if still available */
962 	i = port->line;
963 	if (i < nr_uarts && serial8250_ports[i].port.type == PORT_UNKNOWN &&
964 			serial8250_ports[i].port.iobase == 0)
965 		return &serial8250_ports[i];
966 	/*
967 	 * We didn't find a matching entry, so look for the first
968 	 * free entry.  We look for one which hasn't been previously
969 	 * used (indicated by zero iobase).
970 	 */
971 	for (i = 0; i < nr_uarts; i++)
972 		if (serial8250_ports[i].port.type == PORT_UNKNOWN &&
973 		    serial8250_ports[i].port.iobase == 0)
974 			return &serial8250_ports[i];
975 
976 	/*
977 	 * That also failed.  Last resort is to find any entry which
978 	 * doesn't have a real port associated with it.
979 	 */
980 	for (i = 0; i < nr_uarts; i++)
981 		if (serial8250_ports[i].port.type == PORT_UNKNOWN)
982 			return &serial8250_ports[i];
983 
984 	return NULL;
985 }
986 
serial_8250_overrun_backoff_work(struct work_struct * work)987 static void serial_8250_overrun_backoff_work(struct work_struct *work)
988 {
989 	struct uart_8250_port *up =
990 	    container_of(to_delayed_work(work), struct uart_8250_port,
991 			 overrun_backoff);
992 	struct uart_port *port = &up->port;
993 	unsigned long flags;
994 
995 	spin_lock_irqsave(&port->lock, flags);
996 	up->ier |= UART_IER_RLSI | UART_IER_RDI;
997 	up->port.read_status_mask |= UART_LSR_DR;
998 	serial_out(up, UART_IER, up->ier);
999 	spin_unlock_irqrestore(&port->lock, flags);
1000 }
1001 
1002 /**
1003  *	serial8250_register_8250_port - register a serial port
1004  *	@up: serial port template
1005  *
1006  *	Configure the serial port specified by the request. If the
1007  *	port exists and is in use, it is hung up and unregistered
1008  *	first.
1009  *
1010  *	The port is then probed and if necessary the IRQ is autodetected
1011  *	If this fails an error is returned.
1012  *
1013  *	On success the port is ready to use and the line number is returned.
1014  */
serial8250_register_8250_port(const struct uart_8250_port * up)1015 int serial8250_register_8250_port(const struct uart_8250_port *up)
1016 {
1017 	struct uart_8250_port *uart;
1018 	int ret = -ENOSPC;
1019 
1020 	if (up->port.uartclk == 0)
1021 		return -EINVAL;
1022 
1023 	mutex_lock(&serial_mutex);
1024 
1025 	uart = serial8250_find_match_or_unused(&up->port);
1026 	if (!uart) {
1027 		/*
1028 		 * If the port is past the initial isa ports, initialize a new
1029 		 * port and increment nr_uarts accordingly.
1030 		 */
1031 		uart = serial8250_setup_port(nr_uarts);
1032 		if (!uart)
1033 			goto unlock;
1034 		nr_uarts++;
1035 	}
1036 
1037 	if (uart->port.type != PORT_8250_CIR) {
1038 		struct mctrl_gpios *gpios;
1039 
1040 		if (uart->port.dev)
1041 			uart_remove_one_port(&serial8250_reg, &uart->port);
1042 
1043 		uart->port.ctrl_id	= up->port.ctrl_id;
1044 		uart->port.port_id	= up->port.port_id;
1045 		uart->port.iobase       = up->port.iobase;
1046 		uart->port.membase      = up->port.membase;
1047 		uart->port.irq          = up->port.irq;
1048 		uart->port.irqflags     = up->port.irqflags;
1049 		uart->port.uartclk      = up->port.uartclk;
1050 		uart->port.fifosize     = up->port.fifosize;
1051 		uart->port.regshift     = up->port.regshift;
1052 		uart->port.iotype       = up->port.iotype;
1053 		uart->port.flags        = up->port.flags | UPF_BOOT_AUTOCONF;
1054 		uart->bugs		= up->bugs;
1055 		uart->port.mapbase      = up->port.mapbase;
1056 		uart->port.mapsize      = up->port.mapsize;
1057 		uart->port.private_data = up->port.private_data;
1058 		uart->tx_loadsz		= up->tx_loadsz;
1059 		uart->capabilities	= up->capabilities;
1060 		uart->port.throttle	= up->port.throttle;
1061 		uart->port.unthrottle	= up->port.unthrottle;
1062 		uart->port.rs485_config	= up->port.rs485_config;
1063 		uart->port.rs485_supported = up->port.rs485_supported;
1064 		uart->port.rs485	= up->port.rs485;
1065 		uart->rs485_start_tx	= up->rs485_start_tx;
1066 		uart->rs485_stop_tx	= up->rs485_stop_tx;
1067 		uart->lsr_save_mask	= up->lsr_save_mask;
1068 		uart->dma		= up->dma;
1069 
1070 		/* Take tx_loadsz from fifosize if it wasn't set separately */
1071 		if (uart->port.fifosize && !uart->tx_loadsz)
1072 			uart->tx_loadsz = uart->port.fifosize;
1073 
1074 		if (up->port.dev) {
1075 			uart->port.dev = up->port.dev;
1076 			ret = uart_get_rs485_mode(&uart->port);
1077 			if (ret)
1078 				goto err;
1079 		}
1080 
1081 		if (up->port.flags & UPF_FIXED_TYPE)
1082 			uart->port.type = up->port.type;
1083 
1084 		/*
1085 		 * Only call mctrl_gpio_init(), if the device has no ACPI
1086 		 * companion device
1087 		 */
1088 		if (!has_acpi_companion(uart->port.dev)) {
1089 			gpios = mctrl_gpio_init(&uart->port, 0);
1090 			if (IS_ERR(gpios)) {
1091 				ret = PTR_ERR(gpios);
1092 				goto err;
1093 			} else {
1094 				uart->gpios = gpios;
1095 			}
1096 		}
1097 
1098 		serial8250_set_defaults(uart);
1099 
1100 		/* Possibly override default I/O functions.  */
1101 		if (up->port.serial_in)
1102 			uart->port.serial_in = up->port.serial_in;
1103 		if (up->port.serial_out)
1104 			uart->port.serial_out = up->port.serial_out;
1105 		if (up->port.handle_irq)
1106 			uart->port.handle_irq = up->port.handle_irq;
1107 		/*  Possibly override set_termios call */
1108 		if (up->port.set_termios)
1109 			uart->port.set_termios = up->port.set_termios;
1110 		if (up->port.set_ldisc)
1111 			uart->port.set_ldisc = up->port.set_ldisc;
1112 		if (up->port.get_mctrl)
1113 			uart->port.get_mctrl = up->port.get_mctrl;
1114 		if (up->port.set_mctrl)
1115 			uart->port.set_mctrl = up->port.set_mctrl;
1116 		if (up->port.get_divisor)
1117 			uart->port.get_divisor = up->port.get_divisor;
1118 		if (up->port.set_divisor)
1119 			uart->port.set_divisor = up->port.set_divisor;
1120 		if (up->port.startup)
1121 			uart->port.startup = up->port.startup;
1122 		if (up->port.shutdown)
1123 			uart->port.shutdown = up->port.shutdown;
1124 		if (up->port.pm)
1125 			uart->port.pm = up->port.pm;
1126 		if (up->port.handle_break)
1127 			uart->port.handle_break = up->port.handle_break;
1128 		if (up->dl_read)
1129 			uart->dl_read = up->dl_read;
1130 		if (up->dl_write)
1131 			uart->dl_write = up->dl_write;
1132 
1133 		if (uart->port.type != PORT_8250_CIR) {
1134 			if (serial8250_isa_config != NULL)
1135 				serial8250_isa_config(0, &uart->port,
1136 						&uart->capabilities);
1137 
1138 			serial8250_apply_quirks(uart);
1139 			ret = uart_add_one_port(&serial8250_reg,
1140 						&uart->port);
1141 			if (ret)
1142 				goto err;
1143 
1144 			ret = uart->port.line;
1145 		} else {
1146 			dev_info(uart->port.dev,
1147 				"skipping CIR port at 0x%lx / 0x%llx, IRQ %d\n",
1148 				uart->port.iobase,
1149 				(unsigned long long)uart->port.mapbase,
1150 				uart->port.irq);
1151 
1152 			ret = 0;
1153 		}
1154 
1155 		if (!uart->lsr_save_mask)
1156 			uart->lsr_save_mask = LSR_SAVE_FLAGS;	/* Use default LSR mask */
1157 
1158 		/* Initialise interrupt backoff work if required */
1159 		if (up->overrun_backoff_time_ms > 0) {
1160 			uart->overrun_backoff_time_ms =
1161 				up->overrun_backoff_time_ms;
1162 			INIT_DELAYED_WORK(&uart->overrun_backoff,
1163 					serial_8250_overrun_backoff_work);
1164 		} else {
1165 			uart->overrun_backoff_time_ms = 0;
1166 		}
1167 	}
1168 
1169 unlock:
1170 	mutex_unlock(&serial_mutex);
1171 
1172 	return ret;
1173 
1174 err:
1175 	uart->port.dev = NULL;
1176 	mutex_unlock(&serial_mutex);
1177 	return ret;
1178 }
1179 EXPORT_SYMBOL(serial8250_register_8250_port);
1180 
1181 /**
1182  *	serial8250_unregister_port - remove a 16x50 serial port at runtime
1183  *	@line: serial line number
1184  *
1185  *	Remove one serial port.  This may not be called from interrupt
1186  *	context.  We hand the port back to the our control.
1187  */
serial8250_unregister_port(int line)1188 void serial8250_unregister_port(int line)
1189 {
1190 	struct uart_8250_port *uart = &serial8250_ports[line];
1191 
1192 	mutex_lock(&serial_mutex);
1193 
1194 	if (uart->em485) {
1195 		unsigned long flags;
1196 
1197 		spin_lock_irqsave(&uart->port.lock, flags);
1198 		serial8250_em485_destroy(uart);
1199 		spin_unlock_irqrestore(&uart->port.lock, flags);
1200 	}
1201 
1202 	uart_remove_one_port(&serial8250_reg, &uart->port);
1203 	if (serial8250_isa_devs) {
1204 		uart->port.flags &= ~UPF_BOOT_AUTOCONF;
1205 		uart->port.type = PORT_UNKNOWN;
1206 		uart->port.dev = &serial8250_isa_devs->dev;
1207 		uart->port.port_id = line;
1208 		uart->capabilities = 0;
1209 		serial8250_init_port(uart);
1210 		serial8250_apply_quirks(uart);
1211 		uart_add_one_port(&serial8250_reg, &uart->port);
1212 	} else {
1213 		uart->port.dev = NULL;
1214 	}
1215 	mutex_unlock(&serial_mutex);
1216 }
1217 EXPORT_SYMBOL(serial8250_unregister_port);
1218 
serial8250_init(void)1219 static int __init serial8250_init(void)
1220 {
1221 	int ret;
1222 
1223 	if (nr_uarts == 0)
1224 		return -ENODEV;
1225 
1226 	serial8250_isa_init_ports();
1227 
1228 	pr_info("Serial: 8250/16550 driver, %d ports, IRQ sharing %s\n",
1229 		nr_uarts, str_enabled_disabled(share_irqs));
1230 
1231 #ifdef CONFIG_SPARC
1232 	ret = sunserial_register_minors(&serial8250_reg, UART_NR);
1233 #else
1234 	serial8250_reg.nr = UART_NR;
1235 	ret = uart_register_driver(&serial8250_reg);
1236 #endif
1237 	if (ret)
1238 		goto out;
1239 
1240 	ret = serial8250_pnp_init();
1241 	if (ret)
1242 		goto unreg_uart_drv;
1243 
1244 	serial8250_isa_devs = platform_device_alloc("serial8250",
1245 						    PLAT8250_DEV_LEGACY);
1246 	if (!serial8250_isa_devs) {
1247 		ret = -ENOMEM;
1248 		goto unreg_pnp;
1249 	}
1250 
1251 	ret = platform_device_add(serial8250_isa_devs);
1252 	if (ret)
1253 		goto put_dev;
1254 
1255 	serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev);
1256 
1257 	ret = platform_driver_register(&serial8250_isa_driver);
1258 	if (ret == 0)
1259 		goto out;
1260 
1261 	platform_device_del(serial8250_isa_devs);
1262 put_dev:
1263 	platform_device_put(serial8250_isa_devs);
1264 unreg_pnp:
1265 	serial8250_pnp_exit();
1266 unreg_uart_drv:
1267 #ifdef CONFIG_SPARC
1268 	sunserial_unregister_minors(&serial8250_reg, UART_NR);
1269 #else
1270 	uart_unregister_driver(&serial8250_reg);
1271 #endif
1272 out:
1273 	return ret;
1274 }
1275 
serial8250_exit(void)1276 static void __exit serial8250_exit(void)
1277 {
1278 	struct platform_device *isa_dev = serial8250_isa_devs;
1279 
1280 	/*
1281 	 * This tells serial8250_unregister_port() not to re-register
1282 	 * the ports (thereby making serial8250_isa_driver permanently
1283 	 * in use.)
1284 	 */
1285 	serial8250_isa_devs = NULL;
1286 
1287 	platform_driver_unregister(&serial8250_isa_driver);
1288 	platform_device_unregister(isa_dev);
1289 
1290 	serial8250_pnp_exit();
1291 
1292 #ifdef CONFIG_SPARC
1293 	sunserial_unregister_minors(&serial8250_reg, UART_NR);
1294 #else
1295 	uart_unregister_driver(&serial8250_reg);
1296 #endif
1297 }
1298 
1299 module_init(serial8250_init);
1300 module_exit(serial8250_exit);
1301 
1302 MODULE_LICENSE("GPL");
1303 MODULE_DESCRIPTION("Generic 8250/16x50 serial driver");
1304 
1305 module_param_hw(share_irqs, uint, other, 0644);
1306 MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices (unsafe)");
1307 
1308 module_param(nr_uarts, uint, 0644);
1309 MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")");
1310 
1311 module_param(skip_txen_test, uint, 0644);
1312 MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time");
1313 
1314 #ifdef CONFIG_SERIAL_8250_RSA
1315 module_param_hw_array(probe_rsa, ulong, ioport, &probe_rsa_count, 0444);
1316 MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA");
1317 #endif
1318 MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR);
1319 
1320 #ifdef CONFIG_SERIAL_8250_DEPRECATED_OPTIONS
1321 #ifndef MODULE
1322 /* This module was renamed to 8250_core in 3.7.  Keep the old "8250" name
1323  * working as well for the module options so we don't break people.  We
1324  * need to keep the names identical and the convenient macros will happily
1325  * refuse to let us do that by failing the build with redefinition errors
1326  * of global variables.  So we stick them inside a dummy function to avoid
1327  * those conflicts.  The options still get parsed, and the redefined
1328  * MODULE_PARAM_PREFIX lets us keep the "8250." syntax alive.
1329  *
1330  * This is hacky.  I'm sorry.
1331  */
s8250_options(void)1332 static void __used s8250_options(void)
1333 {
1334 #undef MODULE_PARAM_PREFIX
1335 #define MODULE_PARAM_PREFIX "8250_core."
1336 
1337 	module_param_cb(share_irqs, &param_ops_uint, &share_irqs, 0644);
1338 	module_param_cb(nr_uarts, &param_ops_uint, &nr_uarts, 0644);
1339 	module_param_cb(skip_txen_test, &param_ops_uint, &skip_txen_test, 0644);
1340 #ifdef CONFIG_SERIAL_8250_RSA
1341 	__module_param_call(MODULE_PARAM_PREFIX, probe_rsa,
1342 		&param_array_ops, .arr = &__param_arr_probe_rsa,
1343 		0444, -1, 0);
1344 #endif
1345 }
1346 #else
1347 MODULE_ALIAS("8250_core");
1348 #endif
1349 #endif
1350