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1/*
2 * Driver core for serial ports
3 *
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
5 *
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 */
23#include <linux/module.h>
24#include <linux/tty.h>
25#include <linux/tty_flip.h>
26#include <linux/slab.h>
27#include <linux/init.h>
28#include <linux/console.h>
29#include <linux/of.h>
30#include <linux/proc_fs.h>
31#include <linux/seq_file.h>
32#include <linux/device.h>
33#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
34#include <linux/serial_core.h>
35#include <linux/delay.h>
36#include <linux/mutex.h>
37
38#include <asm/irq.h>
39#include <asm/uaccess.h>
40
41/*
42 * This is used to lock changes in serial line configuration.
43 */
44static DEFINE_MUTEX(port_mutex);
45
46/*
47 * lockdep: port->lock is initialized in two places, but we
48 * want only one lock-class:
49 */
50static struct lock_class_key port_lock_key;
51
52#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
53
54static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
55 struct ktermios *old_termios);
56static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
57static void uart_change_pm(struct uart_state *state,
58 enum uart_pm_state pm_state);
59
60static void uart_port_shutdown(struct tty_port *port);
61
62static int uart_dcd_enabled(struct uart_port *uport)
63{
64 return !!(uport->status & UPSTAT_DCD_ENABLE);
65}
66
67/*
68 * This routine is used by the interrupt handler to schedule processing in
69 * the software interrupt portion of the driver.
70 */
71void uart_write_wakeup(struct uart_port *port)
72{
73 struct uart_state *state = port->state;
74 /*
75 * This means you called this function _after_ the port was
76 * closed. No cookie for you.
77 */
78 BUG_ON(!state);
79 tty_wakeup(state->port.tty);
80}
81
82static void uart_stop(struct tty_struct *tty)
83{
84 struct uart_state *state = tty->driver_data;
85 struct uart_port *port = state->uart_port;
86 unsigned long flags;
87
88 spin_lock_irqsave(&port->lock, flags);
89 port->ops->stop_tx(port);
90 spin_unlock_irqrestore(&port->lock, flags);
91}
92
93static void __uart_start(struct tty_struct *tty)
94{
95 struct uart_state *state = tty->driver_data;
96 struct uart_port *port = state->uart_port;
97
98 if (!uart_tx_stopped(port))
99 port->ops->start_tx(port);
100}
101
102static void uart_start(struct tty_struct *tty)
103{
104 struct uart_state *state = tty->driver_data;
105 struct uart_port *port = state->uart_port;
106 unsigned long flags;
107
108 spin_lock_irqsave(&port->lock, flags);
109 __uart_start(tty);
110 spin_unlock_irqrestore(&port->lock, flags);
111}
112
113static void
114uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
115{
116 unsigned long flags;
117 unsigned int old;
118
119 spin_lock_irqsave(&port->lock, flags);
120 old = port->mctrl;
121 port->mctrl = (old & ~clear) | set;
122 if (old != port->mctrl)
123 port->ops->set_mctrl(port, port->mctrl);
124 spin_unlock_irqrestore(&port->lock, flags);
125}
126
127#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
128#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
129
130/*
131 * Startup the port. This will be called once per open. All calls
132 * will be serialised by the per-port mutex.
133 */
134static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
135 int init_hw)
136{
137 struct uart_port *uport = state->uart_port;
138 unsigned long page;
139 int retval = 0;
140
141 if (uport->type == PORT_UNKNOWN)
142 return 1;
143
144 /*
145 * Make sure the device is in D0 state.
146 */
147 uart_change_pm(state, UART_PM_STATE_ON);
148
149 /*
150 * Initialise and allocate the transmit and temporary
151 * buffer.
152 */
153 if (!state->xmit.buf) {
154 /* This is protected by the per port mutex */
155 page = get_zeroed_page(GFP_KERNEL);
156 if (!page)
157 return -ENOMEM;
158
159 state->xmit.buf = (unsigned char *) page;
160 uart_circ_clear(&state->xmit);
161 }
162
163 retval = uport->ops->startup(uport);
164 if (retval == 0) {
165 if (uart_console(uport) && uport->cons->cflag) {
166 tty->termios.c_cflag = uport->cons->cflag;
167 uport->cons->cflag = 0;
168 }
169 /*
170 * Initialise the hardware port settings.
171 */
172 uart_change_speed(tty, state, NULL);
173
174 /*
175 * Setup the RTS and DTR signals once the
176 * port is open and ready to respond.
177 */
178 if (init_hw && C_BAUD(tty))
179 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
180 }
181
182 /*
183 * This is to allow setserial on this port. People may want to set
184 * port/irq/type and then reconfigure the port properly if it failed
185 * now.
186 */
187 if (retval && capable(CAP_SYS_ADMIN))
188 return 1;
189
190 return retval;
191}
192
193static int uart_startup(struct tty_struct *tty, struct uart_state *state,
194 int init_hw)
195{
196 struct tty_port *port = &state->port;
197 int retval;
198
199 if (port->flags & ASYNC_INITIALIZED)
200 return 0;
201
202 /*
203 * Set the TTY IO error marker - we will only clear this
204 * once we have successfully opened the port.
205 */
206 set_bit(TTY_IO_ERROR, &tty->flags);
207
208 retval = uart_port_startup(tty, state, init_hw);
209 if (!retval) {
210 set_bit(ASYNCB_INITIALIZED, &port->flags);
211 clear_bit(TTY_IO_ERROR, &tty->flags);
212 } else if (retval > 0)
213 retval = 0;
214
215 return retval;
216}
217
218/*
219 * This routine will shutdown a serial port; interrupts are disabled, and
220 * DTR is dropped if the hangup on close termio flag is on. Calls to
221 * uart_shutdown are serialised by the per-port semaphore.
222 */
223static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
224{
225 struct uart_port *uport = state->uart_port;
226 struct tty_port *port = &state->port;
227
228 /*
229 * Set the TTY IO error marker
230 */
231 if (tty)
232 set_bit(TTY_IO_ERROR, &tty->flags);
233
234 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
235 /*
236 * Turn off DTR and RTS early.
237 */
238 if (uart_console(uport) && tty)
239 uport->cons->cflag = tty->termios.c_cflag;
240
241 if (!tty || C_HUPCL(tty))
242 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
243
244 uart_port_shutdown(port);
245 }
246
247 /*
248 * It's possible for shutdown to be called after suspend if we get
249 * a DCD drop (hangup) at just the right time. Clear suspended bit so
250 * we don't try to resume a port that has been shutdown.
251 */
252 clear_bit(ASYNCB_SUSPENDED, &port->flags);
253
254 /*
255 * Free the transmit buffer page.
256 */
257 if (state->xmit.buf) {
258 free_page((unsigned long)state->xmit.buf);
259 state->xmit.buf = NULL;
260 }
261}
262
263/**
264 * uart_update_timeout - update per-port FIFO timeout.
265 * @port: uart_port structure describing the port
266 * @cflag: termios cflag value
267 * @baud: speed of the port
268 *
269 * Set the port FIFO timeout value. The @cflag value should
270 * reflect the actual hardware settings.
271 */
272void
273uart_update_timeout(struct uart_port *port, unsigned int cflag,
274 unsigned int baud)
275{
276 unsigned int bits;
277
278 /* byte size and parity */
279 switch (cflag & CSIZE) {
280 case CS5:
281 bits = 7;
282 break;
283 case CS6:
284 bits = 8;
285 break;
286 case CS7:
287 bits = 9;
288 break;
289 default:
290 bits = 10;
291 break; /* CS8 */
292 }
293
294 if (cflag & CSTOPB)
295 bits++;
296 if (cflag & PARENB)
297 bits++;
298
299 /*
300 * The total number of bits to be transmitted in the fifo.
301 */
302 bits = bits * port->fifosize;
303
304 /*
305 * Figure the timeout to send the above number of bits.
306 * Add .02 seconds of slop
307 */
308 port->timeout = (HZ * bits) / baud + HZ/50;
309}
310
311EXPORT_SYMBOL(uart_update_timeout);
312
313/**
314 * uart_get_baud_rate - return baud rate for a particular port
315 * @port: uart_port structure describing the port in question.
316 * @termios: desired termios settings.
317 * @old: old termios (or NULL)
318 * @min: minimum acceptable baud rate
319 * @max: maximum acceptable baud rate
320 *
321 * Decode the termios structure into a numeric baud rate,
322 * taking account of the magic 38400 baud rate (with spd_*
323 * flags), and mapping the %B0 rate to 9600 baud.
324 *
325 * If the new baud rate is invalid, try the old termios setting.
326 * If it's still invalid, we try 9600 baud.
327 *
328 * Update the @termios structure to reflect the baud rate
329 * we're actually going to be using. Don't do this for the case
330 * where B0 is requested ("hang up").
331 */
332unsigned int
333uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
334 struct ktermios *old, unsigned int min, unsigned int max)
335{
336 unsigned int try;
337 unsigned int baud;
338 unsigned int altbaud;
339 int hung_up = 0;
340 upf_t flags = port->flags & UPF_SPD_MASK;
341
342 switch (flags) {
343 case UPF_SPD_HI:
344 altbaud = 57600;
345 break;
346 case UPF_SPD_VHI:
347 altbaud = 115200;
348 break;
349 case UPF_SPD_SHI:
350 altbaud = 230400;
351 break;
352 case UPF_SPD_WARP:
353 altbaud = 460800;
354 break;
355 default:
356 altbaud = 38400;
357 break;
358 }
359
360 for (try = 0; try < 2; try++) {
361 baud = tty_termios_baud_rate(termios);
362
363 /*
364 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
365 * Die! Die! Die!
366 */
367 if (try == 0 && baud == 38400)
368 baud = altbaud;
369
370 /*
371 * Special case: B0 rate.
372 */
373 if (baud == 0) {
374 hung_up = 1;
375 baud = 9600;
376 }
377
378 if (baud >= min && baud <= max)
379 return baud;
380
381 /*
382 * Oops, the quotient was zero. Try again with
383 * the old baud rate if possible.
384 */
385 termios->c_cflag &= ~CBAUD;
386 if (old) {
387 baud = tty_termios_baud_rate(old);
388 if (!hung_up)
389 tty_termios_encode_baud_rate(termios,
390 baud, baud);
391 old = NULL;
392 continue;
393 }
394
395 /*
396 * As a last resort, if the range cannot be met then clip to
397 * the nearest chip supported rate.
398 */
399 if (!hung_up) {
400 if (baud <= min)
401 tty_termios_encode_baud_rate(termios,
402 min + 1, min + 1);
403 else
404 tty_termios_encode_baud_rate(termios,
405 max - 1, max - 1);
406 }
407 }
408 /* Should never happen */
409 WARN_ON(1);
410 return 0;
411}
412
413EXPORT_SYMBOL(uart_get_baud_rate);
414
415/**
416 * uart_get_divisor - return uart clock divisor
417 * @port: uart_port structure describing the port.
418 * @baud: desired baud rate
419 *
420 * Calculate the uart clock divisor for the port.
421 */
422unsigned int
423uart_get_divisor(struct uart_port *port, unsigned int baud)
424{
425 unsigned int quot;
426
427 /*
428 * Old custom speed handling.
429 */
430 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
431 quot = port->custom_divisor;
432 else
433 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
434
435 return quot;
436}
437
438EXPORT_SYMBOL(uart_get_divisor);
439
440/* Caller holds port mutex */
441static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
442 struct ktermios *old_termios)
443{
444 struct uart_port *uport = state->uart_port;
445 struct ktermios *termios;
446 int hw_stopped;
447
448 /*
449 * If we have no tty, termios, or the port does not exist,
450 * then we can't set the parameters for this port.
451 */
452 if (!tty || uport->type == PORT_UNKNOWN)
453 return;
454
455 termios = &tty->termios;
456 uport->ops->set_termios(uport, termios, old_termios);
457
458 /*
459 * Set modem status enables based on termios cflag
460 */
461 spin_lock_irq(&uport->lock);
462 if (termios->c_cflag & CRTSCTS)
463 uport->status |= UPSTAT_CTS_ENABLE;
464 else
465 uport->status &= ~UPSTAT_CTS_ENABLE;
466
467 if (termios->c_cflag & CLOCAL)
468 uport->status &= ~UPSTAT_DCD_ENABLE;
469 else
470 uport->status |= UPSTAT_DCD_ENABLE;
471
472 /* reset sw-assisted CTS flow control based on (possibly) new mode */
473 hw_stopped = uport->hw_stopped;
474 uport->hw_stopped = uart_softcts_mode(uport) &&
475 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
476 if (uport->hw_stopped) {
477 if (!hw_stopped)
478 uport->ops->stop_tx(uport);
479 } else {
480 if (hw_stopped)
481 __uart_start(tty);
482 }
483 spin_unlock_irq(&uport->lock);
484}
485
486static int uart_put_char(struct tty_struct *tty, unsigned char c)
487{
488 struct uart_state *state = tty->driver_data;
489 struct uart_port *port = state->uart_port;
490 struct circ_buf *circ;
491 unsigned long flags;
492 int ret = 0;
493
494 circ = &state->xmit;
495 if (!circ->buf)
496 return 0;
497
498 spin_lock_irqsave(&port->lock, flags);
499 if (uart_circ_chars_free(circ) != 0) {
500 circ->buf[circ->head] = c;
501 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
502 ret = 1;
503 }
504 spin_unlock_irqrestore(&port->lock, flags);
505 return ret;
506}
507
508static void uart_flush_chars(struct tty_struct *tty)
509{
510 uart_start(tty);
511}
512
513static int uart_write(struct tty_struct *tty,
514 const unsigned char *buf, int count)
515{
516 struct uart_state *state = tty->driver_data;
517 struct uart_port *port;
518 struct circ_buf *circ;
519 unsigned long flags;
520 int c, ret = 0;
521
522 /*
523 * This means you called this function _after_ the port was
524 * closed. No cookie for you.
525 */
526 if (!state) {
527 WARN_ON(1);
528 return -EL3HLT;
529 }
530
531 port = state->uart_port;
532 circ = &state->xmit;
533
534 if (!circ->buf)
535 return 0;
536
537 spin_lock_irqsave(&port->lock, flags);
538 while (1) {
539 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
540 if (count < c)
541 c = count;
542 if (c <= 0)
543 break;
544 memcpy(circ->buf + circ->head, buf, c);
545 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
546 buf += c;
547 count -= c;
548 ret += c;
549 }
550
551 __uart_start(tty);
552 spin_unlock_irqrestore(&port->lock, flags);
553
554 return ret;
555}
556
557static int uart_write_room(struct tty_struct *tty)
558{
559 struct uart_state *state = tty->driver_data;
560 unsigned long flags;
561 int ret;
562
563 spin_lock_irqsave(&state->uart_port->lock, flags);
564 ret = uart_circ_chars_free(&state->xmit);
565 spin_unlock_irqrestore(&state->uart_port->lock, flags);
566 return ret;
567}
568
569static int uart_chars_in_buffer(struct tty_struct *tty)
570{
571 struct uart_state *state = tty->driver_data;
572 unsigned long flags;
573 int ret;
574
575 spin_lock_irqsave(&state->uart_port->lock, flags);
576 ret = uart_circ_chars_pending(&state->xmit);
577 spin_unlock_irqrestore(&state->uart_port->lock, flags);
578 return ret;
579}
580
581static void uart_flush_buffer(struct tty_struct *tty)
582{
583 struct uart_state *state = tty->driver_data;
584 struct uart_port *port;
585 unsigned long flags;
586
587 /*
588 * This means you called this function _after_ the port was
589 * closed. No cookie for you.
590 */
591 if (!state) {
592 WARN_ON(1);
593 return;
594 }
595
596 port = state->uart_port;
597 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
598
599 spin_lock_irqsave(&port->lock, flags);
600 uart_circ_clear(&state->xmit);
601 if (port->ops->flush_buffer)
602 port->ops->flush_buffer(port);
603 spin_unlock_irqrestore(&port->lock, flags);
604 tty_wakeup(tty);
605}
606
607/*
608 * This function is used to send a high-priority XON/XOFF character to
609 * the device
610 */
611static void uart_send_xchar(struct tty_struct *tty, char ch)
612{
613 struct uart_state *state = tty->driver_data;
614 struct uart_port *port = state->uart_port;
615 unsigned long flags;
616
617 if (port->ops->send_xchar)
618 port->ops->send_xchar(port, ch);
619 else {
620 spin_lock_irqsave(&port->lock, flags);
621 port->x_char = ch;
622 if (ch)
623 port->ops->start_tx(port);
624 spin_unlock_irqrestore(&port->lock, flags);
625 }
626}
627
628static void uart_throttle(struct tty_struct *tty)
629{
630 struct uart_state *state = tty->driver_data;
631 struct uart_port *port = state->uart_port;
632 upstat_t mask = 0;
633
634 if (I_IXOFF(tty))
635 mask |= UPSTAT_AUTOXOFF;
636 if (C_CRTSCTS(tty))
637 mask |= UPSTAT_AUTORTS;
638
639 if (port->status & mask) {
640 port->ops->throttle(port);
641 mask &= ~port->status;
642 }
643
644 if (mask & UPSTAT_AUTORTS)
645 uart_clear_mctrl(port, TIOCM_RTS);
646
647 if (mask & UPSTAT_AUTOXOFF)
648 uart_send_xchar(tty, STOP_CHAR(tty));
649}
650
651static void uart_unthrottle(struct tty_struct *tty)
652{
653 struct uart_state *state = tty->driver_data;
654 struct uart_port *port = state->uart_port;
655 upstat_t mask = 0;
656
657 if (I_IXOFF(tty))
658 mask |= UPSTAT_AUTOXOFF;
659 if (C_CRTSCTS(tty))
660 mask |= UPSTAT_AUTORTS;
661
662 if (port->status & mask) {
663 port->ops->unthrottle(port);
664 mask &= ~port->status;
665 }
666
667 if (mask & UPSTAT_AUTORTS)
668 uart_set_mctrl(port, TIOCM_RTS);
669
670 if (mask & UPSTAT_AUTOXOFF)
671 uart_send_xchar(tty, START_CHAR(tty));
672}
673
674static void uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
675{
676 struct uart_state *state = container_of(port, struct uart_state, port);
677 struct uart_port *uport = state->uart_port;
678
679 memset(retinfo, 0, sizeof(*retinfo));
680
681 /*
682 * Ensure the state we copy is consistent and no hardware changes
683 * occur as we go
684 */
685 mutex_lock(&port->mutex);
686 retinfo->type = uport->type;
687 retinfo->line = uport->line;
688 retinfo->port = uport->iobase;
689 if (HIGH_BITS_OFFSET)
690 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
691 retinfo->irq = uport->irq;
692 retinfo->flags = uport->flags;
693 retinfo->xmit_fifo_size = uport->fifosize;
694 retinfo->baud_base = uport->uartclk / 16;
695 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
696 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
697 ASYNC_CLOSING_WAIT_NONE :
698 jiffies_to_msecs(port->closing_wait) / 10;
699 retinfo->custom_divisor = uport->custom_divisor;
700 retinfo->hub6 = uport->hub6;
701 retinfo->io_type = uport->iotype;
702 retinfo->iomem_reg_shift = uport->regshift;
703 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
704 mutex_unlock(&port->mutex);
705}
706
707static int uart_get_info_user(struct tty_port *port,
708 struct serial_struct __user *retinfo)
709{
710 struct serial_struct tmp;
711
712 uart_get_info(port, &tmp);
713
714 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
715 return -EFAULT;
716 return 0;
717}
718
719static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
720 struct uart_state *state,
721 struct serial_struct *new_info)
722{
723 struct uart_port *uport = state->uart_port;
724 unsigned long new_port;
725 unsigned int change_irq, change_port, closing_wait;
726 unsigned int old_custom_divisor, close_delay;
727 upf_t old_flags, new_flags;
728 int retval = 0;
729
730 new_port = new_info->port;
731 if (HIGH_BITS_OFFSET)
732 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
733
734 new_info->irq = irq_canonicalize(new_info->irq);
735 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
736 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
737 ASYNC_CLOSING_WAIT_NONE :
738 msecs_to_jiffies(new_info->closing_wait * 10);
739
740
741 change_irq = !(uport->flags & UPF_FIXED_PORT)
742 && new_info->irq != uport->irq;
743
744 /*
745 * Since changing the 'type' of the port changes its resource
746 * allocations, we should treat type changes the same as
747 * IO port changes.
748 */
749 change_port = !(uport->flags & UPF_FIXED_PORT)
750 && (new_port != uport->iobase ||
751 (unsigned long)new_info->iomem_base != uport->mapbase ||
752 new_info->hub6 != uport->hub6 ||
753 new_info->io_type != uport->iotype ||
754 new_info->iomem_reg_shift != uport->regshift ||
755 new_info->type != uport->type);
756
757 old_flags = uport->flags;
758 new_flags = new_info->flags;
759 old_custom_divisor = uport->custom_divisor;
760
761 if (!capable(CAP_SYS_ADMIN)) {
762 retval = -EPERM;
763 if (change_irq || change_port ||
764 (new_info->baud_base != uport->uartclk / 16) ||
765 (close_delay != port->close_delay) ||
766 (closing_wait != port->closing_wait) ||
767 (new_info->xmit_fifo_size &&
768 new_info->xmit_fifo_size != uport->fifosize) ||
769 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
770 goto exit;
771 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
772 (new_flags & UPF_USR_MASK));
773 uport->custom_divisor = new_info->custom_divisor;
774 goto check_and_exit;
775 }
776
777 /*
778 * Ask the low level driver to verify the settings.
779 */
780 if (uport->ops->verify_port)
781 retval = uport->ops->verify_port(uport, new_info);
782
783 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
784 (new_info->baud_base < 9600))
785 retval = -EINVAL;
786
787 if (retval)
788 goto exit;
789
790 if (change_port || change_irq) {
791 retval = -EBUSY;
792
793 /*
794 * Make sure that we are the sole user of this port.
795 */
796 if (tty_port_users(port) > 1)
797 goto exit;
798
799 /*
800 * We need to shutdown the serial port at the old
801 * port/type/irq combination.
802 */
803 uart_shutdown(tty, state);
804 }
805
806 if (change_port) {
807 unsigned long old_iobase, old_mapbase;
808 unsigned int old_type, old_iotype, old_hub6, old_shift;
809
810 old_iobase = uport->iobase;
811 old_mapbase = uport->mapbase;
812 old_type = uport->type;
813 old_hub6 = uport->hub6;
814 old_iotype = uport->iotype;
815 old_shift = uport->regshift;
816
817 /*
818 * Free and release old regions
819 */
820 if (old_type != PORT_UNKNOWN)
821 uport->ops->release_port(uport);
822
823 uport->iobase = new_port;
824 uport->type = new_info->type;
825 uport->hub6 = new_info->hub6;
826 uport->iotype = new_info->io_type;
827 uport->regshift = new_info->iomem_reg_shift;
828 uport->mapbase = (unsigned long)new_info->iomem_base;
829
830 /*
831 * Claim and map the new regions
832 */
833 if (uport->type != PORT_UNKNOWN) {
834 retval = uport->ops->request_port(uport);
835 } else {
836 /* Always success - Jean II */
837 retval = 0;
838 }
839
840 /*
841 * If we fail to request resources for the
842 * new port, try to restore the old settings.
843 */
844 if (retval) {
845 uport->iobase = old_iobase;
846 uport->type = old_type;
847 uport->hub6 = old_hub6;
848 uport->iotype = old_iotype;
849 uport->regshift = old_shift;
850 uport->mapbase = old_mapbase;
851
852 if (old_type != PORT_UNKNOWN) {
853 retval = uport->ops->request_port(uport);
854 /*
855 * If we failed to restore the old settings,
856 * we fail like this.
857 */
858 if (retval)
859 uport->type = PORT_UNKNOWN;
860
861 /*
862 * We failed anyway.
863 */
864 retval = -EBUSY;
865 }
866
867 /* Added to return the correct error -Ram Gupta */
868 goto exit;
869 }
870 }
871
872 if (change_irq)
873 uport->irq = new_info->irq;
874 if (!(uport->flags & UPF_FIXED_PORT))
875 uport->uartclk = new_info->baud_base * 16;
876 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
877 (new_flags & UPF_CHANGE_MASK);
878 uport->custom_divisor = new_info->custom_divisor;
879 port->close_delay = close_delay;
880 port->closing_wait = closing_wait;
881 if (new_info->xmit_fifo_size)
882 uport->fifosize = new_info->xmit_fifo_size;
883 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
884
885 check_and_exit:
886 retval = 0;
887 if (uport->type == PORT_UNKNOWN)
888 goto exit;
889 if (port->flags & ASYNC_INITIALIZED) {
890 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
891 old_custom_divisor != uport->custom_divisor) {
892 /*
893 * If they're setting up a custom divisor or speed,
894 * instead of clearing it, then bitch about it. No
895 * need to rate-limit; it's CAP_SYS_ADMIN only.
896 */
897 if (uport->flags & UPF_SPD_MASK) {
898 dev_notice(uport->dev,
899 "%s sets custom speed on %s. This is deprecated.\n",
900 current->comm,
901 tty_name(port->tty));
902 }
903 uart_change_speed(tty, state, NULL);
904 }
905 } else
906 retval = uart_startup(tty, state, 1);
907 exit:
908 return retval;
909}
910
911static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
912 struct serial_struct __user *newinfo)
913{
914 struct serial_struct new_serial;
915 struct tty_port *port = &state->port;
916 int retval;
917
918 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
919 return -EFAULT;
920
921 /*
922 * This semaphore protects port->count. It is also
923 * very useful to prevent opens. Also, take the
924 * port configuration semaphore to make sure that a
925 * module insertion/removal doesn't change anything
926 * under us.
927 */
928 mutex_lock(&port->mutex);
929 retval = uart_set_info(tty, port, state, &new_serial);
930 mutex_unlock(&port->mutex);
931 return retval;
932}
933
934/**
935 * uart_get_lsr_info - get line status register info
936 * @tty: tty associated with the UART
937 * @state: UART being queried
938 * @value: returned modem value
939 *
940 * Note: uart_ioctl protects us against hangups.
941 */
942static int uart_get_lsr_info(struct tty_struct *tty,
943 struct uart_state *state, unsigned int __user *value)
944{
945 struct uart_port *uport = state->uart_port;
946 unsigned int result;
947
948 result = uport->ops->tx_empty(uport);
949
950 /*
951 * If we're about to load something into the transmit
952 * register, we'll pretend the transmitter isn't empty to
953 * avoid a race condition (depending on when the transmit
954 * interrupt happens).
955 */
956 if (uport->x_char ||
957 ((uart_circ_chars_pending(&state->xmit) > 0) &&
958 !uart_tx_stopped(uport)))
959 result &= ~TIOCSER_TEMT;
960
961 return put_user(result, value);
962}
963
964static int uart_tiocmget(struct tty_struct *tty)
965{
966 struct uart_state *state = tty->driver_data;
967 struct tty_port *port = &state->port;
968 struct uart_port *uport = state->uart_port;
969 int result = -EIO;
970
971 mutex_lock(&port->mutex);
972 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
973 result = uport->mctrl;
974 spin_lock_irq(&uport->lock);
975 result |= uport->ops->get_mctrl(uport);
976 spin_unlock_irq(&uport->lock);
977 }
978 mutex_unlock(&port->mutex);
979
980 return result;
981}
982
983static int
984uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
985{
986 struct uart_state *state = tty->driver_data;
987 struct uart_port *uport = state->uart_port;
988 struct tty_port *port = &state->port;
989 int ret = -EIO;
990
991 mutex_lock(&port->mutex);
992 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
993 uart_update_mctrl(uport, set, clear);
994 ret = 0;
995 }
996 mutex_unlock(&port->mutex);
997 return ret;
998}
999
1000static int uart_break_ctl(struct tty_struct *tty, int break_state)
1001{
1002 struct uart_state *state = tty->driver_data;
1003 struct tty_port *port = &state->port;
1004 struct uart_port *uport = state->uart_port;
1005
1006 mutex_lock(&port->mutex);
1007
1008 if (uport->type != PORT_UNKNOWN)
1009 uport->ops->break_ctl(uport, break_state);
1010
1011 mutex_unlock(&port->mutex);
1012 return 0;
1013}
1014
1015static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1016{
1017 struct uart_port *uport = state->uart_port;
1018 struct tty_port *port = &state->port;
1019 int flags, ret;
1020
1021 if (!capable(CAP_SYS_ADMIN))
1022 return -EPERM;
1023
1024 /*
1025 * Take the per-port semaphore. This prevents count from
1026 * changing, and hence any extra opens of the port while
1027 * we're auto-configuring.
1028 */
1029 if (mutex_lock_interruptible(&port->mutex))
1030 return -ERESTARTSYS;
1031
1032 ret = -EBUSY;
1033 if (tty_port_users(port) == 1) {
1034 uart_shutdown(tty, state);
1035
1036 /*
1037 * If we already have a port type configured,
1038 * we must release its resources.
1039 */
1040 if (uport->type != PORT_UNKNOWN)
1041 uport->ops->release_port(uport);
1042
1043 flags = UART_CONFIG_TYPE;
1044 if (uport->flags & UPF_AUTO_IRQ)
1045 flags |= UART_CONFIG_IRQ;
1046
1047 /*
1048 * This will claim the ports resources if
1049 * a port is found.
1050 */
1051 uport->ops->config_port(uport, flags);
1052
1053 ret = uart_startup(tty, state, 1);
1054 }
1055 mutex_unlock(&port->mutex);
1056 return ret;
1057}
1058
1059static void uart_enable_ms(struct uart_port *uport)
1060{
1061 /*
1062 * Force modem status interrupts on
1063 */
1064 if (uport->ops->enable_ms)
1065 uport->ops->enable_ms(uport);
1066}
1067
1068/*
1069 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1070 * - mask passed in arg for lines of interest
1071 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1072 * Caller should use TIOCGICOUNT to see which one it was
1073 *
1074 * FIXME: This wants extracting into a common all driver implementation
1075 * of TIOCMWAIT using tty_port.
1076 */
1077static int
1078uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1079{
1080 struct uart_port *uport = state->uart_port;
1081 struct tty_port *port = &state->port;
1082 DECLARE_WAITQUEUE(wait, current);
1083 struct uart_icount cprev, cnow;
1084 int ret;
1085
1086 /*
1087 * note the counters on entry
1088 */
1089 spin_lock_irq(&uport->lock);
1090 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1091 uart_enable_ms(uport);
1092 spin_unlock_irq(&uport->lock);
1093
1094 add_wait_queue(&port->delta_msr_wait, &wait);
1095 for (;;) {
1096 spin_lock_irq(&uport->lock);
1097 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1098 spin_unlock_irq(&uport->lock);
1099
1100 set_current_state(TASK_INTERRUPTIBLE);
1101
1102 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1103 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1104 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1105 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1106 ret = 0;
1107 break;
1108 }
1109
1110 schedule();
1111
1112 /* see if a signal did it */
1113 if (signal_pending(current)) {
1114 ret = -ERESTARTSYS;
1115 break;
1116 }
1117
1118 cprev = cnow;
1119 }
1120 __set_current_state(TASK_RUNNING);
1121 remove_wait_queue(&port->delta_msr_wait, &wait);
1122
1123 return ret;
1124}
1125
1126/*
1127 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1128 * Return: write counters to the user passed counter struct
1129 * NB: both 1->0 and 0->1 transitions are counted except for
1130 * RI where only 0->1 is counted.
1131 */
1132static int uart_get_icount(struct tty_struct *tty,
1133 struct serial_icounter_struct *icount)
1134{
1135 struct uart_state *state = tty->driver_data;
1136 struct uart_icount cnow;
1137 struct uart_port *uport = state->uart_port;
1138
1139 spin_lock_irq(&uport->lock);
1140 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1141 spin_unlock_irq(&uport->lock);
1142
1143 icount->cts = cnow.cts;
1144 icount->dsr = cnow.dsr;
1145 icount->rng = cnow.rng;
1146 icount->dcd = cnow.dcd;
1147 icount->rx = cnow.rx;
1148 icount->tx = cnow.tx;
1149 icount->frame = cnow.frame;
1150 icount->overrun = cnow.overrun;
1151 icount->parity = cnow.parity;
1152 icount->brk = cnow.brk;
1153 icount->buf_overrun = cnow.buf_overrun;
1154
1155 return 0;
1156}
1157
1158static int uart_get_rs485_config(struct uart_port *port,
1159 struct serial_rs485 __user *rs485)
1160{
1161 unsigned long flags;
1162 struct serial_rs485 aux;
1163
1164 spin_lock_irqsave(&port->lock, flags);
1165 aux = port->rs485;
1166 spin_unlock_irqrestore(&port->lock, flags);
1167
1168 if (copy_to_user(rs485, &aux, sizeof(aux)))
1169 return -EFAULT;
1170
1171 return 0;
1172}
1173
1174static int uart_set_rs485_config(struct uart_port *port,
1175 struct serial_rs485 __user *rs485_user)
1176{
1177 struct serial_rs485 rs485;
1178 int ret;
1179 unsigned long flags;
1180
1181 if (!port->rs485_config)
1182 return -ENOIOCTLCMD;
1183
1184 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1185 return -EFAULT;
1186
1187 spin_lock_irqsave(&port->lock, flags);
1188 ret = port->rs485_config(port, &rs485);
1189 spin_unlock_irqrestore(&port->lock, flags);
1190 if (ret)
1191 return ret;
1192
1193 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1194 return -EFAULT;
1195
1196 return 0;
1197}
1198
1199/*
1200 * Called via sys_ioctl. We can use spin_lock_irq() here.
1201 */
1202static int
1203uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1204 unsigned long arg)
1205{
1206 struct uart_state *state = tty->driver_data;
1207 struct tty_port *port = &state->port;
1208 void __user *uarg = (void __user *)arg;
1209 int ret = -ENOIOCTLCMD;
1210
1211
1212 /*
1213 * These ioctls don't rely on the hardware to be present.
1214 */
1215 switch (cmd) {
1216 case TIOCGSERIAL:
1217 ret = uart_get_info_user(port, uarg);
1218 break;
1219
1220 case TIOCSSERIAL:
1221 down_write(&tty->termios_rwsem);
1222 ret = uart_set_info_user(tty, state, uarg);
1223 up_write(&tty->termios_rwsem);
1224 break;
1225
1226 case TIOCSERCONFIG:
1227 down_write(&tty->termios_rwsem);
1228 ret = uart_do_autoconfig(tty, state);
1229 up_write(&tty->termios_rwsem);
1230 break;
1231
1232 case TIOCSERGWILD: /* obsolete */
1233 case TIOCSERSWILD: /* obsolete */
1234 ret = 0;
1235 break;
1236 }
1237
1238 if (ret != -ENOIOCTLCMD)
1239 goto out;
1240
1241 if (tty->flags & (1 << TTY_IO_ERROR)) {
1242 ret = -EIO;
1243 goto out;
1244 }
1245
1246 /*
1247 * The following should only be used when hardware is present.
1248 */
1249 switch (cmd) {
1250 case TIOCMIWAIT:
1251 ret = uart_wait_modem_status(state, arg);
1252 break;
1253 }
1254
1255 if (ret != -ENOIOCTLCMD)
1256 goto out;
1257
1258 mutex_lock(&port->mutex);
1259
1260 if (tty->flags & (1 << TTY_IO_ERROR)) {
1261 ret = -EIO;
1262 goto out_up;
1263 }
1264
1265 /*
1266 * All these rely on hardware being present and need to be
1267 * protected against the tty being hung up.
1268 */
1269
1270 switch (cmd) {
1271 case TIOCSERGETLSR: /* Get line status register */
1272 ret = uart_get_lsr_info(tty, state, uarg);
1273 break;
1274
1275 case TIOCGRS485:
1276 ret = uart_get_rs485_config(state->uart_port, uarg);
1277 break;
1278
1279 case TIOCSRS485:
1280 ret = uart_set_rs485_config(state->uart_port, uarg);
1281 break;
1282 default: {
1283 struct uart_port *uport = state->uart_port;
1284 if (uport->ops->ioctl)
1285 ret = uport->ops->ioctl(uport, cmd, arg);
1286 break;
1287 }
1288 }
1289out_up:
1290 mutex_unlock(&port->mutex);
1291out:
1292 return ret;
1293}
1294
1295static void uart_set_ldisc(struct tty_struct *tty)
1296{
1297 struct uart_state *state = tty->driver_data;
1298 struct uart_port *uport = state->uart_port;
1299
1300 if (uport->ops->set_ldisc) {
1301 mutex_lock(&state->port.mutex);
1302 uport->ops->set_ldisc(uport, &tty->termios);
1303 mutex_unlock(&state->port.mutex);
1304 }
1305}
1306
1307static void uart_set_termios(struct tty_struct *tty,
1308 struct ktermios *old_termios)
1309{
1310 struct uart_state *state = tty->driver_data;
1311 struct uart_port *uport = state->uart_port;
1312 unsigned int cflag = tty->termios.c_cflag;
1313 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1314 bool sw_changed = false;
1315
1316 /*
1317 * Drivers doing software flow control also need to know
1318 * about changes to these input settings.
1319 */
1320 if (uport->flags & UPF_SOFT_FLOW) {
1321 iflag_mask |= IXANY|IXON|IXOFF;
1322 sw_changed =
1323 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1324 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1325 }
1326
1327 /*
1328 * These are the bits that are used to setup various
1329 * flags in the low level driver. We can ignore the Bfoo
1330 * bits in c_cflag; c_[io]speed will always be set
1331 * appropriately by set_termios() in tty_ioctl.c
1332 */
1333 if ((cflag ^ old_termios->c_cflag) == 0 &&
1334 tty->termios.c_ospeed == old_termios->c_ospeed &&
1335 tty->termios.c_ispeed == old_termios->c_ispeed &&
1336 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1337 !sw_changed) {
1338 return;
1339 }
1340
1341 mutex_lock(&state->port.mutex);
1342 uart_change_speed(tty, state, old_termios);
1343 mutex_unlock(&state->port.mutex);
1344 /* reload cflag from termios; port driver may have overriden flags */
1345 cflag = tty->termios.c_cflag;
1346
1347 /* Handle transition to B0 status */
1348 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1349 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1350 /* Handle transition away from B0 status */
1351 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1352 unsigned int mask = TIOCM_DTR;
1353 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
1354 mask |= TIOCM_RTS;
1355 uart_set_mctrl(uport, mask);
1356 }
1357}
1358
1359/*
1360 * Calls to uart_close() are serialised via the tty_lock in
1361 * drivers/tty/tty_io.c:tty_release()
1362 * drivers/tty/tty_io.c:do_tty_hangup()
1363 * This runs from a workqueue and can sleep for a _short_ time only.
1364 */
1365static void uart_close(struct tty_struct *tty, struct file *filp)
1366{
1367 struct uart_state *state = tty->driver_data;
1368 struct tty_port *port;
1369 struct uart_port *uport;
1370
1371 if (!state) {
1372 struct uart_driver *drv = tty->driver->driver_state;
1373
1374 state = drv->state + tty->index;
1375 port = &state->port;
1376 spin_lock_irq(&port->lock);
1377 --port->count;
1378 spin_unlock_irq(&port->lock);
1379 return;
1380 }
1381
1382 uport = state->uart_port;
1383 port = &state->port;
1384 pr_debug("uart_close(%d) called\n", tty->index);
1385
1386 if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1387 return;
1388
1389 /*
1390 * At this point, we stop accepting input. To do this, we
1391 * disable the receive line status interrupts.
1392 */
1393 if (port->flags & ASYNC_INITIALIZED) {
1394 spin_lock_irq(&uport->lock);
1395 uport->ops->stop_rx(uport);
1396 spin_unlock_irq(&uport->lock);
1397 /*
1398 * Before we drop DTR, make sure the UART transmitter
1399 * has completely drained; this is especially
1400 * important if there is a transmit FIFO!
1401 */
1402 uart_wait_until_sent(tty, uport->timeout);
1403 }
1404
1405 mutex_lock(&port->mutex);
1406 uart_shutdown(tty, state);
1407 tty_port_tty_set(port, NULL);
1408
1409 spin_lock_irq(&port->lock);
1410
1411 if (port->blocked_open) {
1412 spin_unlock_irq(&port->lock);
1413 if (port->close_delay)
1414 msleep_interruptible(jiffies_to_msecs(port->close_delay));
1415 spin_lock_irq(&port->lock);
1416 } else if (!uart_console(uport)) {
1417 spin_unlock_irq(&port->lock);
1418 uart_change_pm(state, UART_PM_STATE_OFF);
1419 spin_lock_irq(&port->lock);
1420 }
1421
1422 /*
1423 * Wake up anyone trying to open this port.
1424 */
1425 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1426 spin_unlock_irq(&port->lock);
1427 wake_up_interruptible(&port->open_wait);
1428
1429 mutex_unlock(&port->mutex);
1430
1431 tty_ldisc_flush(tty);
1432 tty->closing = 0;
1433}
1434
1435static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1436{
1437 struct uart_state *state = tty->driver_data;
1438 struct uart_port *port = state->uart_port;
1439 unsigned long char_time, expire;
1440
1441 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1442 return;
1443
1444 /*
1445 * Set the check interval to be 1/5 of the estimated time to
1446 * send a single character, and make it at least 1. The check
1447 * interval should also be less than the timeout.
1448 *
1449 * Note: we have to use pretty tight timings here to satisfy
1450 * the NIST-PCTS.
1451 */
1452 char_time = (port->timeout - HZ/50) / port->fifosize;
1453 char_time = char_time / 5;
1454 if (char_time == 0)
1455 char_time = 1;
1456 if (timeout && timeout < char_time)
1457 char_time = timeout;
1458
1459 /*
1460 * If the transmitter hasn't cleared in twice the approximate
1461 * amount of time to send the entire FIFO, it probably won't
1462 * ever clear. This assumes the UART isn't doing flow
1463 * control, which is currently the case. Hence, if it ever
1464 * takes longer than port->timeout, this is probably due to a
1465 * UART bug of some kind. So, we clamp the timeout parameter at
1466 * 2*port->timeout.
1467 */
1468 if (timeout == 0 || timeout > 2 * port->timeout)
1469 timeout = 2 * port->timeout;
1470
1471 expire = jiffies + timeout;
1472
1473 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1474 port->line, jiffies, expire);
1475
1476 /*
1477 * Check whether the transmitter is empty every 'char_time'.
1478 * 'timeout' / 'expire' give us the maximum amount of time
1479 * we wait.
1480 */
1481 while (!port->ops->tx_empty(port)) {
1482 msleep_interruptible(jiffies_to_msecs(char_time));
1483 if (signal_pending(current))
1484 break;
1485 if (time_after(jiffies, expire))
1486 break;
1487 }
1488}
1489
1490/*
1491 * Calls to uart_hangup() are serialised by the tty_lock in
1492 * drivers/tty/tty_io.c:do_tty_hangup()
1493 * This runs from a workqueue and can sleep for a _short_ time only.
1494 */
1495static void uart_hangup(struct tty_struct *tty)
1496{
1497 struct uart_state *state = tty->driver_data;
1498 struct tty_port *port = &state->port;
1499 unsigned long flags;
1500
1501 pr_debug("uart_hangup(%d)\n", tty->index);
1502
1503 mutex_lock(&port->mutex);
1504 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1505 uart_flush_buffer(tty);
1506 uart_shutdown(tty, state);
1507 spin_lock_irqsave(&port->lock, flags);
1508 port->count = 0;
1509 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1510 spin_unlock_irqrestore(&port->lock, flags);
1511 tty_port_tty_set(port, NULL);
1512 if (!uart_console(state->uart_port))
1513 uart_change_pm(state, UART_PM_STATE_OFF);
1514 wake_up_interruptible(&port->open_wait);
1515 wake_up_interruptible(&port->delta_msr_wait);
1516 }
1517 mutex_unlock(&port->mutex);
1518}
1519
1520static void uart_port_shutdown(struct tty_port *port)
1521{
1522 struct uart_state *state = container_of(port, struct uart_state, port);
1523 struct uart_port *uport = state->uart_port;
1524
1525 /*
1526 * clear delta_msr_wait queue to avoid mem leaks: we may free
1527 * the irq here so the queue might never be woken up. Note
1528 * that we won't end up waiting on delta_msr_wait again since
1529 * any outstanding file descriptors should be pointing at
1530 * hung_up_tty_fops now.
1531 */
1532 wake_up_interruptible(&port->delta_msr_wait);
1533
1534 /*
1535 * Free the IRQ and disable the port.
1536 */
1537 uport->ops->shutdown(uport);
1538
1539 /*
1540 * Ensure that the IRQ handler isn't running on another CPU.
1541 */
1542 synchronize_irq(uport->irq);
1543}
1544
1545static int uart_carrier_raised(struct tty_port *port)
1546{
1547 struct uart_state *state = container_of(port, struct uart_state, port);
1548 struct uart_port *uport = state->uart_port;
1549 int mctrl;
1550 spin_lock_irq(&uport->lock);
1551 uart_enable_ms(uport);
1552 mctrl = uport->ops->get_mctrl(uport);
1553 spin_unlock_irq(&uport->lock);
1554 if (mctrl & TIOCM_CAR)
1555 return 1;
1556 return 0;
1557}
1558
1559static void uart_dtr_rts(struct tty_port *port, int onoff)
1560{
1561 struct uart_state *state = container_of(port, struct uart_state, port);
1562 struct uart_port *uport = state->uart_port;
1563
1564 if (onoff)
1565 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1566 else
1567 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1568}
1569
1570/*
1571 * Calls to uart_open are serialised by the tty_lock in
1572 * drivers/tty/tty_io.c:tty_open()
1573 * Note that if this fails, then uart_close() _will_ be called.
1574 *
1575 * In time, we want to scrap the "opening nonpresent ports"
1576 * behaviour and implement an alternative way for setserial
1577 * to set base addresses/ports/types. This will allow us to
1578 * get rid of a certain amount of extra tests.
1579 */
1580static int uart_open(struct tty_struct *tty, struct file *filp)
1581{
1582 struct uart_driver *drv = tty->driver->driver_state;
1583 int retval, line = tty->index;
1584 struct uart_state *state = drv->state + line;
1585 struct tty_port *port = &state->port;
1586
1587 pr_debug("uart_open(%d) called\n", line);
1588
1589 spin_lock_irq(&port->lock);
1590 ++port->count;
1591 spin_unlock_irq(&port->lock);
1592
1593 /*
1594 * We take the semaphore here to guarantee that we won't be re-entered
1595 * while allocating the state structure, or while we request any IRQs
1596 * that the driver may need. This also has the nice side-effect that
1597 * it delays the action of uart_hangup, so we can guarantee that
1598 * state->port.tty will always contain something reasonable.
1599 */
1600 if (mutex_lock_interruptible(&port->mutex)) {
1601 retval = -ERESTARTSYS;
1602 goto end;
1603 }
1604
1605 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1606 retval = -ENXIO;
1607 goto err_unlock;
1608 }
1609
1610 tty->driver_data = state;
1611 state->uart_port->state = state;
1612 state->port.low_latency =
1613 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1614 tty_port_tty_set(port, tty);
1615
1616 /*
1617 * Start up the serial port.
1618 */
1619 retval = uart_startup(tty, state, 0);
1620
1621 /*
1622 * If we succeeded, wait until the port is ready.
1623 */
1624err_unlock:
1625 mutex_unlock(&port->mutex);
1626 if (retval == 0)
1627 retval = tty_port_block_til_ready(port, tty, filp);
1628end:
1629 return retval;
1630}
1631
1632static const char *uart_type(struct uart_port *port)
1633{
1634 const char *str = NULL;
1635
1636 if (port->ops->type)
1637 str = port->ops->type(port);
1638
1639 if (!str)
1640 str = "unknown";
1641
1642 return str;
1643}
1644
1645#ifdef CONFIG_PROC_FS
1646
1647static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1648{
1649 struct uart_state *state = drv->state + i;
1650 struct tty_port *port = &state->port;
1651 enum uart_pm_state pm_state;
1652 struct uart_port *uport = state->uart_port;
1653 char stat_buf[32];
1654 unsigned int status;
1655 int mmio;
1656
1657 if (!uport)
1658 return;
1659
1660 mmio = uport->iotype >= UPIO_MEM;
1661 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1662 uport->line, uart_type(uport),
1663 mmio ? "mmio:0x" : "port:",
1664 mmio ? (unsigned long long)uport->mapbase
1665 : (unsigned long long)uport->iobase,
1666 uport->irq);
1667
1668 if (uport->type == PORT_UNKNOWN) {
1669 seq_putc(m, '\n');
1670 return;
1671 }
1672
1673 if (capable(CAP_SYS_ADMIN)) {
1674 mutex_lock(&port->mutex);
1675 pm_state = state->pm_state;
1676 if (pm_state != UART_PM_STATE_ON)
1677 uart_change_pm(state, UART_PM_STATE_ON);
1678 spin_lock_irq(&uport->lock);
1679 status = uport->ops->get_mctrl(uport);
1680 spin_unlock_irq(&uport->lock);
1681 if (pm_state != UART_PM_STATE_ON)
1682 uart_change_pm(state, pm_state);
1683 mutex_unlock(&port->mutex);
1684
1685 seq_printf(m, " tx:%d rx:%d",
1686 uport->icount.tx, uport->icount.rx);
1687 if (uport->icount.frame)
1688 seq_printf(m, " fe:%d", uport->icount.frame);
1689 if (uport->icount.parity)
1690 seq_printf(m, " pe:%d", uport->icount.parity);
1691 if (uport->icount.brk)
1692 seq_printf(m, " brk:%d", uport->icount.brk);
1693 if (uport->icount.overrun)
1694 seq_printf(m, " oe:%d", uport->icount.overrun);
1695
1696#define INFOBIT(bit, str) \
1697 if (uport->mctrl & (bit)) \
1698 strncat(stat_buf, (str), sizeof(stat_buf) - \
1699 strlen(stat_buf) - 2)
1700#define STATBIT(bit, str) \
1701 if (status & (bit)) \
1702 strncat(stat_buf, (str), sizeof(stat_buf) - \
1703 strlen(stat_buf) - 2)
1704
1705 stat_buf[0] = '\0';
1706 stat_buf[1] = '\0';
1707 INFOBIT(TIOCM_RTS, "|RTS");
1708 STATBIT(TIOCM_CTS, "|CTS");
1709 INFOBIT(TIOCM_DTR, "|DTR");
1710 STATBIT(TIOCM_DSR, "|DSR");
1711 STATBIT(TIOCM_CAR, "|CD");
1712 STATBIT(TIOCM_RNG, "|RI");
1713 if (stat_buf[0])
1714 stat_buf[0] = ' ';
1715
1716 seq_puts(m, stat_buf);
1717 }
1718 seq_putc(m, '\n');
1719#undef STATBIT
1720#undef INFOBIT
1721}
1722
1723static int uart_proc_show(struct seq_file *m, void *v)
1724{
1725 struct tty_driver *ttydrv = m->private;
1726 struct uart_driver *drv = ttydrv->driver_state;
1727 int i;
1728
1729 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
1730 for (i = 0; i < drv->nr; i++)
1731 uart_line_info(m, drv, i);
1732 return 0;
1733}
1734
1735static int uart_proc_open(struct inode *inode, struct file *file)
1736{
1737 return single_open(file, uart_proc_show, PDE_DATA(inode));
1738}
1739
1740static const struct file_operations uart_proc_fops = {
1741 .owner = THIS_MODULE,
1742 .open = uart_proc_open,
1743 .read = seq_read,
1744 .llseek = seq_lseek,
1745 .release = single_release,
1746};
1747#endif
1748
1749#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1750/**
1751 * uart_console_write - write a console message to a serial port
1752 * @port: the port to write the message
1753 * @s: array of characters
1754 * @count: number of characters in string to write
1755 * @putchar: function to write character to port
1756 */
1757void uart_console_write(struct uart_port *port, const char *s,
1758 unsigned int count,
1759 void (*putchar)(struct uart_port *, int))
1760{
1761 unsigned int i;
1762
1763 for (i = 0; i < count; i++, s++) {
1764 if (*s == '\n')
1765 putchar(port, '\r');
1766 putchar(port, *s);
1767 }
1768}
1769EXPORT_SYMBOL_GPL(uart_console_write);
1770
1771/*
1772 * Check whether an invalid uart number has been specified, and
1773 * if so, search for the first available port that does have
1774 * console support.
1775 */
1776struct uart_port * __init
1777uart_get_console(struct uart_port *ports, int nr, struct console *co)
1778{
1779 int idx = co->index;
1780
1781 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1782 ports[idx].membase == NULL))
1783 for (idx = 0; idx < nr; idx++)
1784 if (ports[idx].iobase != 0 ||
1785 ports[idx].membase != NULL)
1786 break;
1787
1788 co->index = idx;
1789
1790 return ports + idx;
1791}
1792
1793/**
1794 * uart_parse_earlycon - Parse earlycon options
1795 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1796 * @iotype: ptr for decoded iotype (out)
1797 * @addr: ptr for decoded mapbase/iobase (out)
1798 * @options: ptr for <options> field; NULL if not present (out)
1799 *
1800 * Decodes earlycon kernel command line parameters of the form
1801 * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1802 * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1803 *
1804 * The optional form
1805 * earlycon=<name>,0x<addr>,<options>
1806 * console=<name>,0x<addr>,<options>
1807 * is also accepted; the returned @iotype will be UPIO_MEM.
1808 *
1809 * Returns 0 on success or -EINVAL on failure
1810 */
1811int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
1812 char **options)
1813{
1814 if (strncmp(p, "mmio,", 5) == 0) {
1815 *iotype = UPIO_MEM;
1816 p += 5;
1817 } else if (strncmp(p, "mmio16,", 7) == 0) {
1818 *iotype = UPIO_MEM16;
1819 p += 7;
1820 } else if (strncmp(p, "mmio32,", 7) == 0) {
1821 *iotype = UPIO_MEM32;
1822 p += 7;
1823 } else if (strncmp(p, "mmio32be,", 9) == 0) {
1824 *iotype = UPIO_MEM32BE;
1825 p += 9;
1826 } else if (strncmp(p, "mmio32native,", 13) == 0) {
1827 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
1828 UPIO_MEM32BE : UPIO_MEM32;
1829 p += 13;
1830 } else if (strncmp(p, "io,", 3) == 0) {
1831 *iotype = UPIO_PORT;
1832 p += 3;
1833 } else if (strncmp(p, "0x", 2) == 0) {
1834 *iotype = UPIO_MEM;
1835 } else {
1836 return -EINVAL;
1837 }
1838
1839 *addr = simple_strtoul(p, NULL, 0);
1840 p = strchr(p, ',');
1841 if (p)
1842 p++;
1843
1844 *options = p;
1845 return 0;
1846}
1847EXPORT_SYMBOL_GPL(uart_parse_earlycon);
1848
1849/**
1850 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1851 * @options: pointer to option string
1852 * @baud: pointer to an 'int' variable for the baud rate.
1853 * @parity: pointer to an 'int' variable for the parity.
1854 * @bits: pointer to an 'int' variable for the number of data bits.
1855 * @flow: pointer to an 'int' variable for the flow control character.
1856 *
1857 * uart_parse_options decodes a string containing the serial console
1858 * options. The format of the string is <baud><parity><bits><flow>,
1859 * eg: 115200n8r
1860 */
1861void
1862uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1863{
1864 char *s = options;
1865
1866 *baud = simple_strtoul(s, NULL, 10);
1867 while (*s >= '0' && *s <= '9')
1868 s++;
1869 if (*s)
1870 *parity = *s++;
1871 if (*s)
1872 *bits = *s++ - '0';
1873 if (*s)
1874 *flow = *s;
1875}
1876EXPORT_SYMBOL_GPL(uart_parse_options);
1877
1878/**
1879 * uart_set_options - setup the serial console parameters
1880 * @port: pointer to the serial ports uart_port structure
1881 * @co: console pointer
1882 * @baud: baud rate
1883 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1884 * @bits: number of data bits
1885 * @flow: flow control character - 'r' (rts)
1886 */
1887int
1888uart_set_options(struct uart_port *port, struct console *co,
1889 int baud, int parity, int bits, int flow)
1890{
1891 struct ktermios termios;
1892 static struct ktermios dummy;
1893
1894 /*
1895 * Ensure that the serial console lock is initialised
1896 * early.
1897 * If this port is a console, then the spinlock is already
1898 * initialised.
1899 */
1900 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1901 spin_lock_init(&port->lock);
1902 lockdep_set_class(&port->lock, &port_lock_key);
1903 }
1904
1905 memset(&termios, 0, sizeof(struct ktermios));
1906
1907 termios.c_cflag |= CREAD | HUPCL | CLOCAL;
1908 tty_termios_encode_baud_rate(&termios, baud, baud);
1909
1910 if (bits == 7)
1911 termios.c_cflag |= CS7;
1912 else
1913 termios.c_cflag |= CS8;
1914
1915 switch (parity) {
1916 case 'o': case 'O':
1917 termios.c_cflag |= PARODD;
1918 /*fall through*/
1919 case 'e': case 'E':
1920 termios.c_cflag |= PARENB;
1921 break;
1922 }
1923
1924 if (flow == 'r')
1925 termios.c_cflag |= CRTSCTS;
1926
1927 /*
1928 * some uarts on other side don't support no flow control.
1929 * So we set * DTR in host uart to make them happy
1930 */
1931 port->mctrl |= TIOCM_DTR;
1932
1933 port->ops->set_termios(port, &termios, &dummy);
1934 /*
1935 * Allow the setting of the UART parameters with a NULL console
1936 * too:
1937 */
1938 if (co)
1939 co->cflag = termios.c_cflag;
1940
1941 return 0;
1942}
1943EXPORT_SYMBOL_GPL(uart_set_options);
1944#endif /* CONFIG_SERIAL_CORE_CONSOLE */
1945
1946/**
1947 * uart_change_pm - set power state of the port
1948 *
1949 * @state: port descriptor
1950 * @pm_state: new state
1951 *
1952 * Locking: port->mutex has to be held
1953 */
1954static void uart_change_pm(struct uart_state *state,
1955 enum uart_pm_state pm_state)
1956{
1957 struct uart_port *port = state->uart_port;
1958
1959 if (state->pm_state != pm_state) {
1960 if (port->ops->pm)
1961 port->ops->pm(port, pm_state, state->pm_state);
1962 state->pm_state = pm_state;
1963 }
1964}
1965
1966struct uart_match {
1967 struct uart_port *port;
1968 struct uart_driver *driver;
1969};
1970
1971static int serial_match_port(struct device *dev, void *data)
1972{
1973 struct uart_match *match = data;
1974 struct tty_driver *tty_drv = match->driver->tty_driver;
1975 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1976 match->port->line;
1977
1978 return dev->devt == devt; /* Actually, only one tty per port */
1979}
1980
1981int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1982{
1983 struct uart_state *state = drv->state + uport->line;
1984 struct tty_port *port = &state->port;
1985 struct device *tty_dev;
1986 struct uart_match match = {uport, drv};
1987
1988 mutex_lock(&port->mutex);
1989
1990 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1991 if (device_may_wakeup(tty_dev)) {
1992 if (!enable_irq_wake(uport->irq))
1993 uport->irq_wake = 1;
1994 put_device(tty_dev);
1995 mutex_unlock(&port->mutex);
1996 return 0;
1997 }
1998 put_device(tty_dev);
1999
2000 /* Nothing to do if the console is not suspending */
2001 if (!console_suspend_enabled && uart_console(uport))
2002 goto unlock;
2003
2004 uport->suspended = 1;
2005
2006 if (port->flags & ASYNC_INITIALIZED) {
2007 const struct uart_ops *ops = uport->ops;
2008 int tries;
2009
2010 set_bit(ASYNCB_SUSPENDED, &port->flags);
2011 clear_bit(ASYNCB_INITIALIZED, &port->flags);
2012
2013 spin_lock_irq(&uport->lock);
2014 ops->stop_tx(uport);
2015 ops->set_mctrl(uport, 0);
2016 ops->stop_rx(uport);
2017 spin_unlock_irq(&uport->lock);
2018
2019 /*
2020 * Wait for the transmitter to empty.
2021 */
2022 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2023 msleep(10);
2024 if (!tries)
2025 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
2026 drv->dev_name,
2027 drv->tty_driver->name_base + uport->line);
2028
2029 ops->shutdown(uport);
2030 }
2031
2032 /*
2033 * Disable the console device before suspending.
2034 */
2035 if (uart_console(uport))
2036 console_stop(uport->cons);
2037
2038 uart_change_pm(state, UART_PM_STATE_OFF);
2039unlock:
2040 mutex_unlock(&port->mutex);
2041
2042 return 0;
2043}
2044
2045int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2046{
2047 struct uart_state *state = drv->state + uport->line;
2048 struct tty_port *port = &state->port;
2049 struct device *tty_dev;
2050 struct uart_match match = {uport, drv};
2051 struct ktermios termios;
2052
2053 mutex_lock(&port->mutex);
2054
2055 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2056 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2057 if (uport->irq_wake) {
2058 disable_irq_wake(uport->irq);
2059 uport->irq_wake = 0;
2060 }
2061 put_device(tty_dev);
2062 mutex_unlock(&port->mutex);
2063 return 0;
2064 }
2065 put_device(tty_dev);
2066 uport->suspended = 0;
2067
2068 /*
2069 * Re-enable the console device after suspending.
2070 */
2071 if (uart_console(uport)) {
2072 /*
2073 * First try to use the console cflag setting.
2074 */
2075 memset(&termios, 0, sizeof(struct ktermios));
2076 termios.c_cflag = uport->cons->cflag;
2077
2078 /*
2079 * If that's unset, use the tty termios setting.
2080 */
2081 if (port->tty && termios.c_cflag == 0)
2082 termios = port->tty->termios;
2083
2084 if (console_suspend_enabled)
2085 uart_change_pm(state, UART_PM_STATE_ON);
2086 uport->ops->set_termios(uport, &termios, NULL);
2087 if (console_suspend_enabled)
2088 console_start(uport->cons);
2089 }
2090
2091 if (port->flags & ASYNC_SUSPENDED) {
2092 const struct uart_ops *ops = uport->ops;
2093 int ret;
2094
2095 uart_change_pm(state, UART_PM_STATE_ON);
2096 spin_lock_irq(&uport->lock);
2097 ops->set_mctrl(uport, 0);
2098 spin_unlock_irq(&uport->lock);
2099 if (console_suspend_enabled || !uart_console(uport)) {
2100 /* Protected by port mutex for now */
2101 struct tty_struct *tty = port->tty;
2102 ret = ops->startup(uport);
2103 if (ret == 0) {
2104 if (tty)
2105 uart_change_speed(tty, state, NULL);
2106 spin_lock_irq(&uport->lock);
2107 ops->set_mctrl(uport, uport->mctrl);
2108 ops->start_tx(uport);
2109 spin_unlock_irq(&uport->lock);
2110 set_bit(ASYNCB_INITIALIZED, &port->flags);
2111 } else {
2112 /*
2113 * Failed to resume - maybe hardware went away?
2114 * Clear the "initialized" flag so we won't try
2115 * to call the low level drivers shutdown method.
2116 */
2117 uart_shutdown(tty, state);
2118 }
2119 }
2120
2121 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2122 }
2123
2124 mutex_unlock(&port->mutex);
2125
2126 return 0;
2127}
2128
2129static inline void
2130uart_report_port(struct uart_driver *drv, struct uart_port *port)
2131{
2132 char address[64];
2133
2134 switch (port->iotype) {
2135 case UPIO_PORT:
2136 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2137 break;
2138 case UPIO_HUB6:
2139 snprintf(address, sizeof(address),
2140 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2141 break;
2142 case UPIO_MEM:
2143 case UPIO_MEM16:
2144 case UPIO_MEM32:
2145 case UPIO_MEM32BE:
2146 case UPIO_AU:
2147 case UPIO_TSI:
2148 snprintf(address, sizeof(address),
2149 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2150 break;
2151 default:
2152 strlcpy(address, "*unknown*", sizeof(address));
2153 break;
2154 }
2155
2156 printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2157 port->dev ? dev_name(port->dev) : "",
2158 port->dev ? ": " : "",
2159 drv->dev_name,
2160 drv->tty_driver->name_base + port->line,
2161 address, port->irq, port->uartclk / 16, uart_type(port));
2162}
2163
2164static void
2165uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2166 struct uart_port *port)
2167{
2168 unsigned int flags;
2169
2170 /*
2171 * If there isn't a port here, don't do anything further.
2172 */
2173 if (!port->iobase && !port->mapbase && !port->membase)
2174 return;
2175
2176 /*
2177 * Now do the auto configuration stuff. Note that config_port
2178 * is expected to claim the resources and map the port for us.
2179 */
2180 flags = 0;
2181 if (port->flags & UPF_AUTO_IRQ)
2182 flags |= UART_CONFIG_IRQ;
2183 if (port->flags & UPF_BOOT_AUTOCONF) {
2184 if (!(port->flags & UPF_FIXED_TYPE)) {
2185 port->type = PORT_UNKNOWN;
2186 flags |= UART_CONFIG_TYPE;
2187 }
2188 port->ops->config_port(port, flags);
2189 }
2190
2191 if (port->type != PORT_UNKNOWN) {
2192 unsigned long flags;
2193
2194 uart_report_port(drv, port);
2195
2196 /* Power up port for set_mctrl() */
2197 uart_change_pm(state, UART_PM_STATE_ON);
2198
2199 /*
2200 * Ensure that the modem control lines are de-activated.
2201 * keep the DTR setting that is set in uart_set_options()
2202 * We probably don't need a spinlock around this, but
2203 */
2204 spin_lock_irqsave(&port->lock, flags);
2205 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2206 spin_unlock_irqrestore(&port->lock, flags);
2207
2208 /*
2209 * If this driver supports console, and it hasn't been
2210 * successfully registered yet, try to re-register it.
2211 * It may be that the port was not available.
2212 */
2213 if (port->cons && !(port->cons->flags & CON_ENABLED))
2214 register_console(port->cons);
2215
2216 /*
2217 * Power down all ports by default, except the
2218 * console if we have one.
2219 */
2220 if (!uart_console(port))
2221 uart_change_pm(state, UART_PM_STATE_OFF);
2222 }
2223}
2224
2225#ifdef CONFIG_CONSOLE_POLL
2226
2227static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2228{
2229 struct uart_driver *drv = driver->driver_state;
2230 struct uart_state *state = drv->state + line;
2231 struct uart_port *port;
2232 int baud = 9600;
2233 int bits = 8;
2234 int parity = 'n';
2235 int flow = 'n';
2236 int ret;
2237
2238 if (!state || !state->uart_port)
2239 return -1;
2240
2241 port = state->uart_port;
2242 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2243 return -1;
2244
2245 if (port->ops->poll_init) {
2246 struct tty_port *tport = &state->port;
2247
2248 ret = 0;
2249 mutex_lock(&tport->mutex);
2250 /*
2251 * We don't set ASYNCB_INITIALIZED as we only initialized the
2252 * hw, e.g. state->xmit is still uninitialized.
2253 */
2254 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2255 ret = port->ops->poll_init(port);
2256 mutex_unlock(&tport->mutex);
2257 if (ret)
2258 return ret;
2259 }
2260
2261 if (options) {
2262 uart_parse_options(options, &baud, &parity, &bits, &flow);
2263 return uart_set_options(port, NULL, baud, parity, bits, flow);
2264 }
2265
2266 return 0;
2267}
2268
2269static int uart_poll_get_char(struct tty_driver *driver, int line)
2270{
2271 struct uart_driver *drv = driver->driver_state;
2272 struct uart_state *state = drv->state + line;
2273 struct uart_port *port;
2274
2275 if (!state || !state->uart_port)
2276 return -1;
2277
2278 port = state->uart_port;
2279 return port->ops->poll_get_char(port);
2280}
2281
2282static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2283{
2284 struct uart_driver *drv = driver->driver_state;
2285 struct uart_state *state = drv->state + line;
2286 struct uart_port *port;
2287
2288 if (!state || !state->uart_port)
2289 return;
2290
2291 port = state->uart_port;
2292
2293 if (ch == '\n')
2294 port->ops->poll_put_char(port, '\r');
2295 port->ops->poll_put_char(port, ch);
2296}
2297#endif
2298
2299static const struct tty_operations uart_ops = {
2300 .open = uart_open,
2301 .close = uart_close,
2302 .write = uart_write,
2303 .put_char = uart_put_char,
2304 .flush_chars = uart_flush_chars,
2305 .write_room = uart_write_room,
2306 .chars_in_buffer= uart_chars_in_buffer,
2307 .flush_buffer = uart_flush_buffer,
2308 .ioctl = uart_ioctl,
2309 .throttle = uart_throttle,
2310 .unthrottle = uart_unthrottle,
2311 .send_xchar = uart_send_xchar,
2312 .set_termios = uart_set_termios,
2313 .set_ldisc = uart_set_ldisc,
2314 .stop = uart_stop,
2315 .start = uart_start,
2316 .hangup = uart_hangup,
2317 .break_ctl = uart_break_ctl,
2318 .wait_until_sent= uart_wait_until_sent,
2319#ifdef CONFIG_PROC_FS
2320 .proc_fops = &uart_proc_fops,
2321#endif
2322 .tiocmget = uart_tiocmget,
2323 .tiocmset = uart_tiocmset,
2324 .get_icount = uart_get_icount,
2325#ifdef CONFIG_CONSOLE_POLL
2326 .poll_init = uart_poll_init,
2327 .poll_get_char = uart_poll_get_char,
2328 .poll_put_char = uart_poll_put_char,
2329#endif
2330};
2331
2332static const struct tty_port_operations uart_port_ops = {
2333 .carrier_raised = uart_carrier_raised,
2334 .dtr_rts = uart_dtr_rts,
2335};
2336
2337/**
2338 * uart_register_driver - register a driver with the uart core layer
2339 * @drv: low level driver structure
2340 *
2341 * Register a uart driver with the core driver. We in turn register
2342 * with the tty layer, and initialise the core driver per-port state.
2343 *
2344 * We have a proc file in /proc/tty/driver which is named after the
2345 * normal driver.
2346 *
2347 * drv->port should be NULL, and the per-port structures should be
2348 * registered using uart_add_one_port after this call has succeeded.
2349 */
2350int uart_register_driver(struct uart_driver *drv)
2351{
2352 struct tty_driver *normal;
2353 int i, retval;
2354
2355 BUG_ON(drv->state);
2356
2357 /*
2358 * Maybe we should be using a slab cache for this, especially if
2359 * we have a large number of ports to handle.
2360 */
2361 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2362 if (!drv->state)
2363 goto out;
2364
2365 normal = alloc_tty_driver(drv->nr);
2366 if (!normal)
2367 goto out_kfree;
2368
2369 drv->tty_driver = normal;
2370
2371 normal->driver_name = drv->driver_name;
2372 normal->name = drv->dev_name;
2373 normal->major = drv->major;
2374 normal->minor_start = drv->minor;
2375 normal->type = TTY_DRIVER_TYPE_SERIAL;
2376 normal->subtype = SERIAL_TYPE_NORMAL;
2377 normal->init_termios = tty_std_termios;
2378 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2379 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2380 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2381 normal->driver_state = drv;
2382 tty_set_operations(normal, &uart_ops);
2383
2384 /*
2385 * Initialise the UART state(s).
2386 */
2387 for (i = 0; i < drv->nr; i++) {
2388 struct uart_state *state = drv->state + i;
2389 struct tty_port *port = &state->port;
2390
2391 tty_port_init(port);
2392 port->ops = &uart_port_ops;
2393 }
2394
2395 retval = tty_register_driver(normal);
2396 if (retval >= 0)
2397 return retval;
2398
2399 for (i = 0; i < drv->nr; i++)
2400 tty_port_destroy(&drv->state[i].port);
2401 put_tty_driver(normal);
2402out_kfree:
2403 kfree(drv->state);
2404out:
2405 return -ENOMEM;
2406}
2407
2408/**
2409 * uart_unregister_driver - remove a driver from the uart core layer
2410 * @drv: low level driver structure
2411 *
2412 * Remove all references to a driver from the core driver. The low
2413 * level driver must have removed all its ports via the
2414 * uart_remove_one_port() if it registered them with uart_add_one_port().
2415 * (ie, drv->port == NULL)
2416 */
2417void uart_unregister_driver(struct uart_driver *drv)
2418{
2419 struct tty_driver *p = drv->tty_driver;
2420 unsigned int i;
2421
2422 tty_unregister_driver(p);
2423 put_tty_driver(p);
2424 for (i = 0; i < drv->nr; i++)
2425 tty_port_destroy(&drv->state[i].port);
2426 kfree(drv->state);
2427 drv->state = NULL;
2428 drv->tty_driver = NULL;
2429}
2430
2431struct tty_driver *uart_console_device(struct console *co, int *index)
2432{
2433 struct uart_driver *p = co->data;
2434 *index = co->index;
2435 return p->tty_driver;
2436}
2437
2438static ssize_t uart_get_attr_uartclk(struct device *dev,
2439 struct device_attribute *attr, char *buf)
2440{
2441 struct serial_struct tmp;
2442 struct tty_port *port = dev_get_drvdata(dev);
2443
2444 uart_get_info(port, &tmp);
2445 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2446}
2447
2448static ssize_t uart_get_attr_type(struct device *dev,
2449 struct device_attribute *attr, char *buf)
2450{
2451 struct serial_struct tmp;
2452 struct tty_port *port = dev_get_drvdata(dev);
2453
2454 uart_get_info(port, &tmp);
2455 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2456}
2457static ssize_t uart_get_attr_line(struct device *dev,
2458 struct device_attribute *attr, char *buf)
2459{
2460 struct serial_struct tmp;
2461 struct tty_port *port = dev_get_drvdata(dev);
2462
2463 uart_get_info(port, &tmp);
2464 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2465}
2466
2467static ssize_t uart_get_attr_port(struct device *dev,
2468 struct device_attribute *attr, char *buf)
2469{
2470 struct serial_struct tmp;
2471 struct tty_port *port = dev_get_drvdata(dev);
2472 unsigned long ioaddr;
2473
2474 uart_get_info(port, &tmp);
2475 ioaddr = tmp.port;
2476 if (HIGH_BITS_OFFSET)
2477 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2478 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2479}
2480
2481static ssize_t uart_get_attr_irq(struct device *dev,
2482 struct device_attribute *attr, char *buf)
2483{
2484 struct serial_struct tmp;
2485 struct tty_port *port = dev_get_drvdata(dev);
2486
2487 uart_get_info(port, &tmp);
2488 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2489}
2490
2491static ssize_t uart_get_attr_flags(struct device *dev,
2492 struct device_attribute *attr, char *buf)
2493{
2494 struct serial_struct tmp;
2495 struct tty_port *port = dev_get_drvdata(dev);
2496
2497 uart_get_info(port, &tmp);
2498 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2499}
2500
2501static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2502 struct device_attribute *attr, char *buf)
2503{
2504 struct serial_struct tmp;
2505 struct tty_port *port = dev_get_drvdata(dev);
2506
2507 uart_get_info(port, &tmp);
2508 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2509}
2510
2511
2512static ssize_t uart_get_attr_close_delay(struct device *dev,
2513 struct device_attribute *attr, char *buf)
2514{
2515 struct serial_struct tmp;
2516 struct tty_port *port = dev_get_drvdata(dev);
2517
2518 uart_get_info(port, &tmp);
2519 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2520}
2521
2522
2523static ssize_t uart_get_attr_closing_wait(struct device *dev,
2524 struct device_attribute *attr, char *buf)
2525{
2526 struct serial_struct tmp;
2527 struct tty_port *port = dev_get_drvdata(dev);
2528
2529 uart_get_info(port, &tmp);
2530 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2531}
2532
2533static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2534 struct device_attribute *attr, char *buf)
2535{
2536 struct serial_struct tmp;
2537 struct tty_port *port = dev_get_drvdata(dev);
2538
2539 uart_get_info(port, &tmp);
2540 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2541}
2542
2543static ssize_t uart_get_attr_io_type(struct device *dev,
2544 struct device_attribute *attr, char *buf)
2545{
2546 struct serial_struct tmp;
2547 struct tty_port *port = dev_get_drvdata(dev);
2548
2549 uart_get_info(port, &tmp);
2550 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2551}
2552
2553static ssize_t uart_get_attr_iomem_base(struct device *dev,
2554 struct device_attribute *attr, char *buf)
2555{
2556 struct serial_struct tmp;
2557 struct tty_port *port = dev_get_drvdata(dev);
2558
2559 uart_get_info(port, &tmp);
2560 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2561}
2562
2563static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2564 struct device_attribute *attr, char *buf)
2565{
2566 struct serial_struct tmp;
2567 struct tty_port *port = dev_get_drvdata(dev);
2568
2569 uart_get_info(port, &tmp);
2570 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2571}
2572
2573static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2574static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2575static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2576static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2577static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2578static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2579static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2580static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2581static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2582static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2583static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2584static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2585static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2586
2587static struct attribute *tty_dev_attrs[] = {
2588 &dev_attr_type.attr,
2589 &dev_attr_line.attr,
2590 &dev_attr_port.attr,
2591 &dev_attr_irq.attr,
2592 &dev_attr_flags.attr,
2593 &dev_attr_xmit_fifo_size.attr,
2594 &dev_attr_uartclk.attr,
2595 &dev_attr_close_delay.attr,
2596 &dev_attr_closing_wait.attr,
2597 &dev_attr_custom_divisor.attr,
2598 &dev_attr_io_type.attr,
2599 &dev_attr_iomem_base.attr,
2600 &dev_attr_iomem_reg_shift.attr,
2601 NULL,
2602 };
2603
2604static const struct attribute_group tty_dev_attr_group = {
2605 .attrs = tty_dev_attrs,
2606 };
2607
2608/**
2609 * uart_add_one_port - attach a driver-defined port structure
2610 * @drv: pointer to the uart low level driver structure for this port
2611 * @uport: uart port structure to use for this port.
2612 *
2613 * This allows the driver to register its own uart_port structure
2614 * with the core driver. The main purpose is to allow the low
2615 * level uart drivers to expand uart_port, rather than having yet
2616 * more levels of structures.
2617 */
2618int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2619{
2620 struct uart_state *state;
2621 struct tty_port *port;
2622 int ret = 0;
2623 struct device *tty_dev;
2624 int num_groups;
2625
2626 BUG_ON(in_interrupt());
2627
2628 if (uport->line >= drv->nr)
2629 return -EINVAL;
2630
2631 state = drv->state + uport->line;
2632 port = &state->port;
2633
2634 mutex_lock(&port_mutex);
2635 mutex_lock(&port->mutex);
2636 if (state->uart_port) {
2637 ret = -EINVAL;
2638 goto out;
2639 }
2640
2641 /* Link the port to the driver state table and vice versa */
2642 state->uart_port = uport;
2643 uport->state = state;
2644
2645 state->pm_state = UART_PM_STATE_UNDEFINED;
2646 uport->cons = drv->cons;
2647 uport->minor = drv->tty_driver->minor_start + uport->line;
2648
2649 /*
2650 * If this port is a console, then the spinlock is already
2651 * initialised.
2652 */
2653 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2654 spin_lock_init(&uport->lock);
2655 lockdep_set_class(&uport->lock, &port_lock_key);
2656 }
2657 if (uport->cons && uport->dev)
2658 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2659
2660 uart_configure_port(drv, state, uport);
2661
2662 num_groups = 2;
2663 if (uport->attr_group)
2664 num_groups++;
2665
2666 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2667 GFP_KERNEL);
2668 if (!uport->tty_groups) {
2669 ret = -ENOMEM;
2670 goto out;
2671 }
2672 uport->tty_groups[0] = &tty_dev_attr_group;
2673 if (uport->attr_group)
2674 uport->tty_groups[1] = uport->attr_group;
2675
2676 /*
2677 * Register the port whether it's detected or not. This allows
2678 * setserial to be used to alter this port's parameters.
2679 */
2680 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2681 uport->line, uport->dev, port, uport->tty_groups);
2682 if (likely(!IS_ERR(tty_dev))) {
2683 device_set_wakeup_capable(tty_dev, 1);
2684 } else {
2685 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2686 uport->line);
2687 }
2688
2689 /*
2690 * Ensure UPF_DEAD is not set.
2691 */
2692 uport->flags &= ~UPF_DEAD;
2693
2694 out:
2695 mutex_unlock(&port->mutex);
2696 mutex_unlock(&port_mutex);
2697
2698 return ret;
2699}
2700
2701/**
2702 * uart_remove_one_port - detach a driver defined port structure
2703 * @drv: pointer to the uart low level driver structure for this port
2704 * @uport: uart port structure for this port
2705 *
2706 * This unhooks (and hangs up) the specified port structure from the
2707 * core driver. No further calls will be made to the low-level code
2708 * for this port.
2709 */
2710int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2711{
2712 struct uart_state *state = drv->state + uport->line;
2713 struct tty_port *port = &state->port;
2714 struct tty_struct *tty;
2715 int ret = 0;
2716
2717 BUG_ON(in_interrupt());
2718
2719 if (state->uart_port != uport)
2720 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2721 state->uart_port, uport);
2722
2723 mutex_lock(&port_mutex);
2724
2725 /*
2726 * Mark the port "dead" - this prevents any opens from
2727 * succeeding while we shut down the port.
2728 */
2729 mutex_lock(&port->mutex);
2730 if (!state->uart_port) {
2731 mutex_unlock(&port->mutex);
2732 ret = -EINVAL;
2733 goto out;
2734 }
2735 uport->flags |= UPF_DEAD;
2736 mutex_unlock(&port->mutex);
2737
2738 /*
2739 * Remove the devices from the tty layer
2740 */
2741 tty_unregister_device(drv->tty_driver, uport->line);
2742
2743 tty = tty_port_tty_get(port);
2744 if (tty) {
2745 tty_vhangup(port->tty);
2746 tty_kref_put(tty);
2747 }
2748
2749 /*
2750 * If the port is used as a console, unregister it
2751 */
2752 if (uart_console(uport))
2753 unregister_console(uport->cons);
2754
2755 /*
2756 * Free the port IO and memory resources, if any.
2757 */
2758 if (uport->type != PORT_UNKNOWN)
2759 uport->ops->release_port(uport);
2760 kfree(uport->tty_groups);
2761
2762 /*
2763 * Indicate that there isn't a port here anymore.
2764 */
2765 uport->type = PORT_UNKNOWN;
2766
2767 state->uart_port = NULL;
2768out:
2769 mutex_unlock(&port_mutex);
2770
2771 return ret;
2772}
2773
2774/*
2775 * Are the two ports equivalent?
2776 */
2777int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2778{
2779 if (port1->iotype != port2->iotype)
2780 return 0;
2781
2782 switch (port1->iotype) {
2783 case UPIO_PORT:
2784 return (port1->iobase == port2->iobase);
2785 case UPIO_HUB6:
2786 return (port1->iobase == port2->iobase) &&
2787 (port1->hub6 == port2->hub6);
2788 case UPIO_MEM:
2789 case UPIO_MEM16:
2790 case UPIO_MEM32:
2791 case UPIO_MEM32BE:
2792 case UPIO_AU:
2793 case UPIO_TSI:
2794 return (port1->mapbase == port2->mapbase);
2795 }
2796 return 0;
2797}
2798EXPORT_SYMBOL(uart_match_port);
2799
2800/**
2801 * uart_handle_dcd_change - handle a change of carrier detect state
2802 * @uport: uart_port structure for the open port
2803 * @status: new carrier detect status, nonzero if active
2804 *
2805 * Caller must hold uport->lock
2806 */
2807void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2808{
2809 struct tty_port *port = &uport->state->port;
2810 struct tty_struct *tty = port->tty;
2811 struct tty_ldisc *ld;
2812
2813 lockdep_assert_held_once(&uport->lock);
2814
2815 if (tty) {
2816 ld = tty_ldisc_ref(tty);
2817 if (ld) {
2818 if (ld->ops->dcd_change)
2819 ld->ops->dcd_change(tty, status);
2820 tty_ldisc_deref(ld);
2821 }
2822 }
2823
2824 uport->icount.dcd++;
2825
2826 if (uart_dcd_enabled(uport)) {
2827 if (status)
2828 wake_up_interruptible(&port->open_wait);
2829 else if (tty)
2830 tty_hangup(tty);
2831 }
2832}
2833EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2834
2835/**
2836 * uart_handle_cts_change - handle a change of clear-to-send state
2837 * @uport: uart_port structure for the open port
2838 * @status: new clear to send status, nonzero if active
2839 *
2840 * Caller must hold uport->lock
2841 */
2842void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2843{
2844 lockdep_assert_held_once(&uport->lock);
2845
2846 uport->icount.cts++;
2847
2848 if (uart_softcts_mode(uport)) {
2849 if (uport->hw_stopped) {
2850 if (status) {
2851 uport->hw_stopped = 0;
2852 uport->ops->start_tx(uport);
2853 uart_write_wakeup(uport);
2854 }
2855 } else {
2856 if (!status) {
2857 uport->hw_stopped = 1;
2858 uport->ops->stop_tx(uport);
2859 }
2860 }
2861
2862 }
2863}
2864EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2865
2866/**
2867 * uart_insert_char - push a char to the uart layer
2868 *
2869 * User is responsible to call tty_flip_buffer_push when they are done with
2870 * insertion.
2871 *
2872 * @port: corresponding port
2873 * @status: state of the serial port RX buffer (LSR for 8250)
2874 * @overrun: mask of overrun bits in @status
2875 * @ch: character to push
2876 * @flag: flag for the character (see TTY_NORMAL and friends)
2877 */
2878void uart_insert_char(struct uart_port *port, unsigned int status,
2879 unsigned int overrun, unsigned int ch, unsigned int flag)
2880{
2881 struct tty_port *tport = &port->state->port;
2882
2883 if ((status & port->ignore_status_mask & ~overrun) == 0)
2884 if (tty_insert_flip_char(tport, ch, flag) == 0)
2885 ++port->icount.buf_overrun;
2886
2887 /*
2888 * Overrun is special. Since it's reported immediately,
2889 * it doesn't affect the current character.
2890 */
2891 if (status & ~port->ignore_status_mask & overrun)
2892 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2893 ++port->icount.buf_overrun;
2894}
2895EXPORT_SYMBOL_GPL(uart_insert_char);
2896
2897EXPORT_SYMBOL(uart_write_wakeup);
2898EXPORT_SYMBOL(uart_register_driver);
2899EXPORT_SYMBOL(uart_unregister_driver);
2900EXPORT_SYMBOL(uart_suspend_port);
2901EXPORT_SYMBOL(uart_resume_port);
2902EXPORT_SYMBOL(uart_add_one_port);
2903EXPORT_SYMBOL(uart_remove_one_port);
2904
2905MODULE_DESCRIPTION("Serial driver core");
2906MODULE_LICENSE("GPL");
1/*
2 * Driver core for serial ports
3 *
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
5 *
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 */
23#include <linux/module.h>
24#include <linux/tty.h>
25#include <linux/tty_flip.h>
26#include <linux/slab.h>
27#include <linux/init.h>
28#include <linux/console.h>
29#include <linux/proc_fs.h>
30#include <linux/seq_file.h>
31#include <linux/device.h>
32#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
33#include <linux/serial_core.h>
34#include <linux/delay.h>
35#include <linux/mutex.h>
36
37#include <asm/irq.h>
38#include <asm/uaccess.h>
39
40/*
41 * This is used to lock changes in serial line configuration.
42 */
43static DEFINE_MUTEX(port_mutex);
44
45/*
46 * lockdep: port->lock is initialized in two places, but we
47 * want only one lock-class:
48 */
49static struct lock_class_key port_lock_key;
50
51#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
52
53static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
54 struct ktermios *old_termios);
55static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
56static void uart_change_pm(struct uart_state *state,
57 enum uart_pm_state pm_state);
58
59static void uart_port_shutdown(struct tty_port *port);
60
61/*
62 * This routine is used by the interrupt handler to schedule processing in
63 * the software interrupt portion of the driver.
64 */
65void uart_write_wakeup(struct uart_port *port)
66{
67 struct uart_state *state = port->state;
68 /*
69 * This means you called this function _after_ the port was
70 * closed. No cookie for you.
71 */
72 BUG_ON(!state);
73 tty_wakeup(state->port.tty);
74}
75
76static void uart_stop(struct tty_struct *tty)
77{
78 struct uart_state *state = tty->driver_data;
79 struct uart_port *port = state->uart_port;
80 unsigned long flags;
81
82 spin_lock_irqsave(&port->lock, flags);
83 port->ops->stop_tx(port);
84 spin_unlock_irqrestore(&port->lock, flags);
85}
86
87static void __uart_start(struct tty_struct *tty)
88{
89 struct uart_state *state = tty->driver_data;
90 struct uart_port *port = state->uart_port;
91
92 if (!tty->stopped && !tty->hw_stopped)
93 port->ops->start_tx(port);
94}
95
96static void uart_start(struct tty_struct *tty)
97{
98 struct uart_state *state = tty->driver_data;
99 struct uart_port *port = state->uart_port;
100 unsigned long flags;
101
102 spin_lock_irqsave(&port->lock, flags);
103 __uart_start(tty);
104 spin_unlock_irqrestore(&port->lock, flags);
105}
106
107static inline void
108uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
109{
110 unsigned long flags;
111 unsigned int old;
112
113 spin_lock_irqsave(&port->lock, flags);
114 old = port->mctrl;
115 port->mctrl = (old & ~clear) | set;
116 if (old != port->mctrl)
117 port->ops->set_mctrl(port, port->mctrl);
118 spin_unlock_irqrestore(&port->lock, flags);
119}
120
121#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
122#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
123
124/*
125 * Startup the port. This will be called once per open. All calls
126 * will be serialised by the per-port mutex.
127 */
128static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
129 int init_hw)
130{
131 struct uart_port *uport = state->uart_port;
132 struct tty_port *port = &state->port;
133 unsigned long page;
134 int retval = 0;
135
136 if (uport->type == PORT_UNKNOWN)
137 return 1;
138
139 /*
140 * Make sure the device is in D0 state.
141 */
142 uart_change_pm(state, UART_PM_STATE_ON);
143
144 /*
145 * Initialise and allocate the transmit and temporary
146 * buffer.
147 */
148 if (!state->xmit.buf) {
149 /* This is protected by the per port mutex */
150 page = get_zeroed_page(GFP_KERNEL);
151 if (!page)
152 return -ENOMEM;
153
154 state->xmit.buf = (unsigned char *) page;
155 uart_circ_clear(&state->xmit);
156 }
157
158 retval = uport->ops->startup(uport);
159 if (retval == 0) {
160 if (uart_console(uport) && uport->cons->cflag) {
161 tty->termios.c_cflag = uport->cons->cflag;
162 uport->cons->cflag = 0;
163 }
164 /*
165 * Initialise the hardware port settings.
166 */
167 uart_change_speed(tty, state, NULL);
168
169 if (init_hw) {
170 /*
171 * Setup the RTS and DTR signals once the
172 * port is open and ready to respond.
173 */
174 if (tty->termios.c_cflag & CBAUD)
175 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
176 }
177
178 if (tty_port_cts_enabled(port)) {
179 spin_lock_irq(&uport->lock);
180 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
181 tty->hw_stopped = 1;
182 spin_unlock_irq(&uport->lock);
183 }
184 }
185
186 /*
187 * This is to allow setserial on this port. People may want to set
188 * port/irq/type and then reconfigure the port properly if it failed
189 * now.
190 */
191 if (retval && capable(CAP_SYS_ADMIN))
192 return 1;
193
194 return retval;
195}
196
197static int uart_startup(struct tty_struct *tty, struct uart_state *state,
198 int init_hw)
199{
200 struct tty_port *port = &state->port;
201 int retval;
202
203 if (port->flags & ASYNC_INITIALIZED)
204 return 0;
205
206 /*
207 * Set the TTY IO error marker - we will only clear this
208 * once we have successfully opened the port.
209 */
210 set_bit(TTY_IO_ERROR, &tty->flags);
211
212 retval = uart_port_startup(tty, state, init_hw);
213 if (!retval) {
214 set_bit(ASYNCB_INITIALIZED, &port->flags);
215 clear_bit(TTY_IO_ERROR, &tty->flags);
216 } else if (retval > 0)
217 retval = 0;
218
219 return retval;
220}
221
222/*
223 * This routine will shutdown a serial port; interrupts are disabled, and
224 * DTR is dropped if the hangup on close termio flag is on. Calls to
225 * uart_shutdown are serialised by the per-port semaphore.
226 */
227static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
228{
229 struct uart_port *uport = state->uart_port;
230 struct tty_port *port = &state->port;
231
232 /*
233 * Set the TTY IO error marker
234 */
235 if (tty)
236 set_bit(TTY_IO_ERROR, &tty->flags);
237
238 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
239 /*
240 * Turn off DTR and RTS early.
241 */
242 if (!tty || (tty->termios.c_cflag & HUPCL))
243 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
244
245 uart_port_shutdown(port);
246 }
247
248 /*
249 * It's possible for shutdown to be called after suspend if we get
250 * a DCD drop (hangup) at just the right time. Clear suspended bit so
251 * we don't try to resume a port that has been shutdown.
252 */
253 clear_bit(ASYNCB_SUSPENDED, &port->flags);
254
255 /*
256 * Free the transmit buffer page.
257 */
258 if (state->xmit.buf) {
259 free_page((unsigned long)state->xmit.buf);
260 state->xmit.buf = NULL;
261 }
262}
263
264/**
265 * uart_update_timeout - update per-port FIFO timeout.
266 * @port: uart_port structure describing the port
267 * @cflag: termios cflag value
268 * @baud: speed of the port
269 *
270 * Set the port FIFO timeout value. The @cflag value should
271 * reflect the actual hardware settings.
272 */
273void
274uart_update_timeout(struct uart_port *port, unsigned int cflag,
275 unsigned int baud)
276{
277 unsigned int bits;
278
279 /* byte size and parity */
280 switch (cflag & CSIZE) {
281 case CS5:
282 bits = 7;
283 break;
284 case CS6:
285 bits = 8;
286 break;
287 case CS7:
288 bits = 9;
289 break;
290 default:
291 bits = 10;
292 break; /* CS8 */
293 }
294
295 if (cflag & CSTOPB)
296 bits++;
297 if (cflag & PARENB)
298 bits++;
299
300 /*
301 * The total number of bits to be transmitted in the fifo.
302 */
303 bits = bits * port->fifosize;
304
305 /*
306 * Figure the timeout to send the above number of bits.
307 * Add .02 seconds of slop
308 */
309 port->timeout = (HZ * bits) / baud + HZ/50;
310}
311
312EXPORT_SYMBOL(uart_update_timeout);
313
314/**
315 * uart_get_baud_rate - return baud rate for a particular port
316 * @port: uart_port structure describing the port in question.
317 * @termios: desired termios settings.
318 * @old: old termios (or NULL)
319 * @min: minimum acceptable baud rate
320 * @max: maximum acceptable baud rate
321 *
322 * Decode the termios structure into a numeric baud rate,
323 * taking account of the magic 38400 baud rate (with spd_*
324 * flags), and mapping the %B0 rate to 9600 baud.
325 *
326 * If the new baud rate is invalid, try the old termios setting.
327 * If it's still invalid, we try 9600 baud.
328 *
329 * Update the @termios structure to reflect the baud rate
330 * we're actually going to be using. Don't do this for the case
331 * where B0 is requested ("hang up").
332 */
333unsigned int
334uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
335 struct ktermios *old, unsigned int min, unsigned int max)
336{
337 unsigned int try, baud, altbaud = 38400;
338 int hung_up = 0;
339 upf_t flags = port->flags & UPF_SPD_MASK;
340
341 if (flags == UPF_SPD_HI)
342 altbaud = 57600;
343 else if (flags == UPF_SPD_VHI)
344 altbaud = 115200;
345 else if (flags == UPF_SPD_SHI)
346 altbaud = 230400;
347 else if (flags == UPF_SPD_WARP)
348 altbaud = 460800;
349
350 for (try = 0; try < 2; try++) {
351 baud = tty_termios_baud_rate(termios);
352
353 /*
354 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
355 * Die! Die! Die!
356 */
357 if (baud == 38400)
358 baud = altbaud;
359
360 /*
361 * Special case: B0 rate.
362 */
363 if (baud == 0) {
364 hung_up = 1;
365 baud = 9600;
366 }
367
368 if (baud >= min && baud <= max)
369 return baud;
370
371 /*
372 * Oops, the quotient was zero. Try again with
373 * the old baud rate if possible.
374 */
375 termios->c_cflag &= ~CBAUD;
376 if (old) {
377 baud = tty_termios_baud_rate(old);
378 if (!hung_up)
379 tty_termios_encode_baud_rate(termios,
380 baud, baud);
381 old = NULL;
382 continue;
383 }
384
385 /*
386 * As a last resort, if the range cannot be met then clip to
387 * the nearest chip supported rate.
388 */
389 if (!hung_up) {
390 if (baud <= min)
391 tty_termios_encode_baud_rate(termios,
392 min + 1, min + 1);
393 else
394 tty_termios_encode_baud_rate(termios,
395 max - 1, max - 1);
396 }
397 }
398 /* Should never happen */
399 WARN_ON(1);
400 return 0;
401}
402
403EXPORT_SYMBOL(uart_get_baud_rate);
404
405/**
406 * uart_get_divisor - return uart clock divisor
407 * @port: uart_port structure describing the port.
408 * @baud: desired baud rate
409 *
410 * Calculate the uart clock divisor for the port.
411 */
412unsigned int
413uart_get_divisor(struct uart_port *port, unsigned int baud)
414{
415 unsigned int quot;
416
417 /*
418 * Old custom speed handling.
419 */
420 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
421 quot = port->custom_divisor;
422 else
423 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
424
425 return quot;
426}
427
428EXPORT_SYMBOL(uart_get_divisor);
429
430/* FIXME: Consistent locking policy */
431static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
432 struct ktermios *old_termios)
433{
434 struct tty_port *port = &state->port;
435 struct uart_port *uport = state->uart_port;
436 struct ktermios *termios;
437
438 /*
439 * If we have no tty, termios, or the port does not exist,
440 * then we can't set the parameters for this port.
441 */
442 if (!tty || uport->type == PORT_UNKNOWN)
443 return;
444
445 termios = &tty->termios;
446
447 /*
448 * Set flags based on termios cflag
449 */
450 if (termios->c_cflag & CRTSCTS)
451 set_bit(ASYNCB_CTS_FLOW, &port->flags);
452 else
453 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
454
455 if (termios->c_cflag & CLOCAL)
456 clear_bit(ASYNCB_CHECK_CD, &port->flags);
457 else
458 set_bit(ASYNCB_CHECK_CD, &port->flags);
459
460 uport->ops->set_termios(uport, termios, old_termios);
461}
462
463static inline int __uart_put_char(struct uart_port *port,
464 struct circ_buf *circ, unsigned char c)
465{
466 unsigned long flags;
467 int ret = 0;
468
469 if (!circ->buf)
470 return 0;
471
472 spin_lock_irqsave(&port->lock, flags);
473 if (uart_circ_chars_free(circ) != 0) {
474 circ->buf[circ->head] = c;
475 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
476 ret = 1;
477 }
478 spin_unlock_irqrestore(&port->lock, flags);
479 return ret;
480}
481
482static int uart_put_char(struct tty_struct *tty, unsigned char ch)
483{
484 struct uart_state *state = tty->driver_data;
485
486 return __uart_put_char(state->uart_port, &state->xmit, ch);
487}
488
489static void uart_flush_chars(struct tty_struct *tty)
490{
491 uart_start(tty);
492}
493
494static int uart_write(struct tty_struct *tty,
495 const unsigned char *buf, int count)
496{
497 struct uart_state *state = tty->driver_data;
498 struct uart_port *port;
499 struct circ_buf *circ;
500 unsigned long flags;
501 int c, ret = 0;
502
503 /*
504 * This means you called this function _after_ the port was
505 * closed. No cookie for you.
506 */
507 if (!state) {
508 WARN_ON(1);
509 return -EL3HLT;
510 }
511
512 port = state->uart_port;
513 circ = &state->xmit;
514
515 if (!circ->buf)
516 return 0;
517
518 spin_lock_irqsave(&port->lock, flags);
519 while (1) {
520 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
521 if (count < c)
522 c = count;
523 if (c <= 0)
524 break;
525 memcpy(circ->buf + circ->head, buf, c);
526 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
527 buf += c;
528 count -= c;
529 ret += c;
530 }
531 spin_unlock_irqrestore(&port->lock, flags);
532
533 uart_start(tty);
534 return ret;
535}
536
537static int uart_write_room(struct tty_struct *tty)
538{
539 struct uart_state *state = tty->driver_data;
540 unsigned long flags;
541 int ret;
542
543 spin_lock_irqsave(&state->uart_port->lock, flags);
544 ret = uart_circ_chars_free(&state->xmit);
545 spin_unlock_irqrestore(&state->uart_port->lock, flags);
546 return ret;
547}
548
549static int uart_chars_in_buffer(struct tty_struct *tty)
550{
551 struct uart_state *state = tty->driver_data;
552 unsigned long flags;
553 int ret;
554
555 spin_lock_irqsave(&state->uart_port->lock, flags);
556 ret = uart_circ_chars_pending(&state->xmit);
557 spin_unlock_irqrestore(&state->uart_port->lock, flags);
558 return ret;
559}
560
561static void uart_flush_buffer(struct tty_struct *tty)
562{
563 struct uart_state *state = tty->driver_data;
564 struct uart_port *port;
565 unsigned long flags;
566
567 /*
568 * This means you called this function _after_ the port was
569 * closed. No cookie for you.
570 */
571 if (!state) {
572 WARN_ON(1);
573 return;
574 }
575
576 port = state->uart_port;
577 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
578
579 spin_lock_irqsave(&port->lock, flags);
580 uart_circ_clear(&state->xmit);
581 if (port->ops->flush_buffer)
582 port->ops->flush_buffer(port);
583 spin_unlock_irqrestore(&port->lock, flags);
584 tty_wakeup(tty);
585}
586
587/*
588 * This function is used to send a high-priority XON/XOFF character to
589 * the device
590 */
591static void uart_send_xchar(struct tty_struct *tty, char ch)
592{
593 struct uart_state *state = tty->driver_data;
594 struct uart_port *port = state->uart_port;
595 unsigned long flags;
596
597 if (port->ops->send_xchar)
598 port->ops->send_xchar(port, ch);
599 else {
600 port->x_char = ch;
601 if (ch) {
602 spin_lock_irqsave(&port->lock, flags);
603 port->ops->start_tx(port);
604 spin_unlock_irqrestore(&port->lock, flags);
605 }
606 }
607}
608
609static void uart_throttle(struct tty_struct *tty)
610{
611 struct uart_state *state = tty->driver_data;
612 struct uart_port *port = state->uart_port;
613 uint32_t mask = 0;
614
615 if (I_IXOFF(tty))
616 mask |= UPF_SOFT_FLOW;
617 if (tty->termios.c_cflag & CRTSCTS)
618 mask |= UPF_HARD_FLOW;
619
620 if (port->flags & mask) {
621 port->ops->throttle(port);
622 mask &= ~port->flags;
623 }
624
625 if (mask & UPF_SOFT_FLOW)
626 uart_send_xchar(tty, STOP_CHAR(tty));
627
628 if (mask & UPF_HARD_FLOW)
629 uart_clear_mctrl(port, TIOCM_RTS);
630}
631
632static void uart_unthrottle(struct tty_struct *tty)
633{
634 struct uart_state *state = tty->driver_data;
635 struct uart_port *port = state->uart_port;
636 uint32_t mask = 0;
637
638 if (I_IXOFF(tty))
639 mask |= UPF_SOFT_FLOW;
640 if (tty->termios.c_cflag & CRTSCTS)
641 mask |= UPF_HARD_FLOW;
642
643 if (port->flags & mask) {
644 port->ops->unthrottle(port);
645 mask &= ~port->flags;
646 }
647
648 if (mask & UPF_SOFT_FLOW) {
649 if (port->x_char)
650 port->x_char = 0;
651 else
652 uart_send_xchar(tty, START_CHAR(tty));
653 }
654
655 if (mask & UPF_HARD_FLOW)
656 uart_set_mctrl(port, TIOCM_RTS);
657}
658
659static void do_uart_get_info(struct tty_port *port,
660 struct serial_struct *retinfo)
661{
662 struct uart_state *state = container_of(port, struct uart_state, port);
663 struct uart_port *uport = state->uart_port;
664
665 memset(retinfo, 0, sizeof(*retinfo));
666
667 retinfo->type = uport->type;
668 retinfo->line = uport->line;
669 retinfo->port = uport->iobase;
670 if (HIGH_BITS_OFFSET)
671 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
672 retinfo->irq = uport->irq;
673 retinfo->flags = uport->flags;
674 retinfo->xmit_fifo_size = uport->fifosize;
675 retinfo->baud_base = uport->uartclk / 16;
676 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
677 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
678 ASYNC_CLOSING_WAIT_NONE :
679 jiffies_to_msecs(port->closing_wait) / 10;
680 retinfo->custom_divisor = uport->custom_divisor;
681 retinfo->hub6 = uport->hub6;
682 retinfo->io_type = uport->iotype;
683 retinfo->iomem_reg_shift = uport->regshift;
684 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
685}
686
687static void uart_get_info(struct tty_port *port,
688 struct serial_struct *retinfo)
689{
690 /* Ensure the state we copy is consistent and no hardware changes
691 occur as we go */
692 mutex_lock(&port->mutex);
693 do_uart_get_info(port, retinfo);
694 mutex_unlock(&port->mutex);
695}
696
697static int uart_get_info_user(struct tty_port *port,
698 struct serial_struct __user *retinfo)
699{
700 struct serial_struct tmp;
701 uart_get_info(port, &tmp);
702
703 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
704 return -EFAULT;
705 return 0;
706}
707
708static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
709 struct uart_state *state,
710 struct serial_struct *new_info)
711{
712 struct uart_port *uport = state->uart_port;
713 unsigned long new_port;
714 unsigned int change_irq, change_port, closing_wait;
715 unsigned int old_custom_divisor, close_delay;
716 upf_t old_flags, new_flags;
717 int retval = 0;
718
719 new_port = new_info->port;
720 if (HIGH_BITS_OFFSET)
721 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
722
723 new_info->irq = irq_canonicalize(new_info->irq);
724 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
725 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
726 ASYNC_CLOSING_WAIT_NONE :
727 msecs_to_jiffies(new_info->closing_wait * 10);
728
729
730 change_irq = !(uport->flags & UPF_FIXED_PORT)
731 && new_info->irq != uport->irq;
732
733 /*
734 * Since changing the 'type' of the port changes its resource
735 * allocations, we should treat type changes the same as
736 * IO port changes.
737 */
738 change_port = !(uport->flags & UPF_FIXED_PORT)
739 && (new_port != uport->iobase ||
740 (unsigned long)new_info->iomem_base != uport->mapbase ||
741 new_info->hub6 != uport->hub6 ||
742 new_info->io_type != uport->iotype ||
743 new_info->iomem_reg_shift != uport->regshift ||
744 new_info->type != uport->type);
745
746 old_flags = uport->flags;
747 new_flags = new_info->flags;
748 old_custom_divisor = uport->custom_divisor;
749
750 if (!capable(CAP_SYS_ADMIN)) {
751 retval = -EPERM;
752 if (change_irq || change_port ||
753 (new_info->baud_base != uport->uartclk / 16) ||
754 (close_delay != port->close_delay) ||
755 (closing_wait != port->closing_wait) ||
756 (new_info->xmit_fifo_size &&
757 new_info->xmit_fifo_size != uport->fifosize) ||
758 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
759 goto exit;
760 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
761 (new_flags & UPF_USR_MASK));
762 uport->custom_divisor = new_info->custom_divisor;
763 goto check_and_exit;
764 }
765
766 /*
767 * Ask the low level driver to verify the settings.
768 */
769 if (uport->ops->verify_port)
770 retval = uport->ops->verify_port(uport, new_info);
771
772 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
773 (new_info->baud_base < 9600))
774 retval = -EINVAL;
775
776 if (retval)
777 goto exit;
778
779 if (change_port || change_irq) {
780 retval = -EBUSY;
781
782 /*
783 * Make sure that we are the sole user of this port.
784 */
785 if (tty_port_users(port) > 1)
786 goto exit;
787
788 /*
789 * We need to shutdown the serial port at the old
790 * port/type/irq combination.
791 */
792 uart_shutdown(tty, state);
793 }
794
795 if (change_port) {
796 unsigned long old_iobase, old_mapbase;
797 unsigned int old_type, old_iotype, old_hub6, old_shift;
798
799 old_iobase = uport->iobase;
800 old_mapbase = uport->mapbase;
801 old_type = uport->type;
802 old_hub6 = uport->hub6;
803 old_iotype = uport->iotype;
804 old_shift = uport->regshift;
805
806 /*
807 * Free and release old regions
808 */
809 if (old_type != PORT_UNKNOWN)
810 uport->ops->release_port(uport);
811
812 uport->iobase = new_port;
813 uport->type = new_info->type;
814 uport->hub6 = new_info->hub6;
815 uport->iotype = new_info->io_type;
816 uport->regshift = new_info->iomem_reg_shift;
817 uport->mapbase = (unsigned long)new_info->iomem_base;
818
819 /*
820 * Claim and map the new regions
821 */
822 if (uport->type != PORT_UNKNOWN) {
823 retval = uport->ops->request_port(uport);
824 } else {
825 /* Always success - Jean II */
826 retval = 0;
827 }
828
829 /*
830 * If we fail to request resources for the
831 * new port, try to restore the old settings.
832 */
833 if (retval) {
834 uport->iobase = old_iobase;
835 uport->type = old_type;
836 uport->hub6 = old_hub6;
837 uport->iotype = old_iotype;
838 uport->regshift = old_shift;
839 uport->mapbase = old_mapbase;
840
841 if (old_type != PORT_UNKNOWN) {
842 retval = uport->ops->request_port(uport);
843 /*
844 * If we failed to restore the old settings,
845 * we fail like this.
846 */
847 if (retval)
848 uport->type = PORT_UNKNOWN;
849
850 /*
851 * We failed anyway.
852 */
853 retval = -EBUSY;
854 }
855
856 /* Added to return the correct error -Ram Gupta */
857 goto exit;
858 }
859 }
860
861 if (change_irq)
862 uport->irq = new_info->irq;
863 if (!(uport->flags & UPF_FIXED_PORT))
864 uport->uartclk = new_info->baud_base * 16;
865 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
866 (new_flags & UPF_CHANGE_MASK);
867 uport->custom_divisor = new_info->custom_divisor;
868 port->close_delay = close_delay;
869 port->closing_wait = closing_wait;
870 if (new_info->xmit_fifo_size)
871 uport->fifosize = new_info->xmit_fifo_size;
872 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
873
874 check_and_exit:
875 retval = 0;
876 if (uport->type == PORT_UNKNOWN)
877 goto exit;
878 if (port->flags & ASYNC_INITIALIZED) {
879 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
880 old_custom_divisor != uport->custom_divisor) {
881 /*
882 * If they're setting up a custom divisor or speed,
883 * instead of clearing it, then bitch about it. No
884 * need to rate-limit; it's CAP_SYS_ADMIN only.
885 */
886 if (uport->flags & UPF_SPD_MASK) {
887 char buf[64];
888 printk(KERN_NOTICE
889 "%s sets custom speed on %s. This "
890 "is deprecated.\n", current->comm,
891 tty_name(port->tty, buf));
892 }
893 uart_change_speed(tty, state, NULL);
894 }
895 } else
896 retval = uart_startup(tty, state, 1);
897 exit:
898 return retval;
899}
900
901static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
902 struct serial_struct __user *newinfo)
903{
904 struct serial_struct new_serial;
905 struct tty_port *port = &state->port;
906 int retval;
907
908 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
909 return -EFAULT;
910
911 /*
912 * This semaphore protects port->count. It is also
913 * very useful to prevent opens. Also, take the
914 * port configuration semaphore to make sure that a
915 * module insertion/removal doesn't change anything
916 * under us.
917 */
918 mutex_lock(&port->mutex);
919 retval = uart_set_info(tty, port, state, &new_serial);
920 mutex_unlock(&port->mutex);
921 return retval;
922}
923
924/**
925 * uart_get_lsr_info - get line status register info
926 * @tty: tty associated with the UART
927 * @state: UART being queried
928 * @value: returned modem value
929 *
930 * Note: uart_ioctl protects us against hangups.
931 */
932static int uart_get_lsr_info(struct tty_struct *tty,
933 struct uart_state *state, unsigned int __user *value)
934{
935 struct uart_port *uport = state->uart_port;
936 unsigned int result;
937
938 result = uport->ops->tx_empty(uport);
939
940 /*
941 * If we're about to load something into the transmit
942 * register, we'll pretend the transmitter isn't empty to
943 * avoid a race condition (depending on when the transmit
944 * interrupt happens).
945 */
946 if (uport->x_char ||
947 ((uart_circ_chars_pending(&state->xmit) > 0) &&
948 !tty->stopped && !tty->hw_stopped))
949 result &= ~TIOCSER_TEMT;
950
951 return put_user(result, value);
952}
953
954static int uart_tiocmget(struct tty_struct *tty)
955{
956 struct uart_state *state = tty->driver_data;
957 struct tty_port *port = &state->port;
958 struct uart_port *uport = state->uart_port;
959 int result = -EIO;
960
961 mutex_lock(&port->mutex);
962 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
963 result = uport->mctrl;
964 spin_lock_irq(&uport->lock);
965 result |= uport->ops->get_mctrl(uport);
966 spin_unlock_irq(&uport->lock);
967 }
968 mutex_unlock(&port->mutex);
969
970 return result;
971}
972
973static int
974uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
975{
976 struct uart_state *state = tty->driver_data;
977 struct uart_port *uport = state->uart_port;
978 struct tty_port *port = &state->port;
979 int ret = -EIO;
980
981 mutex_lock(&port->mutex);
982 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
983 uart_update_mctrl(uport, set, clear);
984 ret = 0;
985 }
986 mutex_unlock(&port->mutex);
987 return ret;
988}
989
990static int uart_break_ctl(struct tty_struct *tty, int break_state)
991{
992 struct uart_state *state = tty->driver_data;
993 struct tty_port *port = &state->port;
994 struct uart_port *uport = state->uart_port;
995
996 mutex_lock(&port->mutex);
997
998 if (uport->type != PORT_UNKNOWN)
999 uport->ops->break_ctl(uport, break_state);
1000
1001 mutex_unlock(&port->mutex);
1002 return 0;
1003}
1004
1005static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1006{
1007 struct uart_port *uport = state->uart_port;
1008 struct tty_port *port = &state->port;
1009 int flags, ret;
1010
1011 if (!capable(CAP_SYS_ADMIN))
1012 return -EPERM;
1013
1014 /*
1015 * Take the per-port semaphore. This prevents count from
1016 * changing, and hence any extra opens of the port while
1017 * we're auto-configuring.
1018 */
1019 if (mutex_lock_interruptible(&port->mutex))
1020 return -ERESTARTSYS;
1021
1022 ret = -EBUSY;
1023 if (tty_port_users(port) == 1) {
1024 uart_shutdown(tty, state);
1025
1026 /*
1027 * If we already have a port type configured,
1028 * we must release its resources.
1029 */
1030 if (uport->type != PORT_UNKNOWN)
1031 uport->ops->release_port(uport);
1032
1033 flags = UART_CONFIG_TYPE;
1034 if (uport->flags & UPF_AUTO_IRQ)
1035 flags |= UART_CONFIG_IRQ;
1036
1037 /*
1038 * This will claim the ports resources if
1039 * a port is found.
1040 */
1041 uport->ops->config_port(uport, flags);
1042
1043 ret = uart_startup(tty, state, 1);
1044 }
1045 mutex_unlock(&port->mutex);
1046 return ret;
1047}
1048
1049/*
1050 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1051 * - mask passed in arg for lines of interest
1052 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1053 * Caller should use TIOCGICOUNT to see which one it was
1054 *
1055 * FIXME: This wants extracting into a common all driver implementation
1056 * of TIOCMWAIT using tty_port.
1057 */
1058static int
1059uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1060{
1061 struct uart_port *uport = state->uart_port;
1062 struct tty_port *port = &state->port;
1063 DECLARE_WAITQUEUE(wait, current);
1064 struct uart_icount cprev, cnow;
1065 int ret;
1066
1067 /*
1068 * note the counters on entry
1069 */
1070 spin_lock_irq(&uport->lock);
1071 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1072
1073 /*
1074 * Force modem status interrupts on
1075 */
1076 uport->ops->enable_ms(uport);
1077 spin_unlock_irq(&uport->lock);
1078
1079 add_wait_queue(&port->delta_msr_wait, &wait);
1080 for (;;) {
1081 spin_lock_irq(&uport->lock);
1082 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1083 spin_unlock_irq(&uport->lock);
1084
1085 set_current_state(TASK_INTERRUPTIBLE);
1086
1087 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1088 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1089 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1090 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1091 ret = 0;
1092 break;
1093 }
1094
1095 schedule();
1096
1097 /* see if a signal did it */
1098 if (signal_pending(current)) {
1099 ret = -ERESTARTSYS;
1100 break;
1101 }
1102
1103 cprev = cnow;
1104 }
1105
1106 current->state = TASK_RUNNING;
1107 remove_wait_queue(&port->delta_msr_wait, &wait);
1108
1109 return ret;
1110}
1111
1112/*
1113 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1114 * Return: write counters to the user passed counter struct
1115 * NB: both 1->0 and 0->1 transitions are counted except for
1116 * RI where only 0->1 is counted.
1117 */
1118static int uart_get_icount(struct tty_struct *tty,
1119 struct serial_icounter_struct *icount)
1120{
1121 struct uart_state *state = tty->driver_data;
1122 struct uart_icount cnow;
1123 struct uart_port *uport = state->uart_port;
1124
1125 spin_lock_irq(&uport->lock);
1126 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1127 spin_unlock_irq(&uport->lock);
1128
1129 icount->cts = cnow.cts;
1130 icount->dsr = cnow.dsr;
1131 icount->rng = cnow.rng;
1132 icount->dcd = cnow.dcd;
1133 icount->rx = cnow.rx;
1134 icount->tx = cnow.tx;
1135 icount->frame = cnow.frame;
1136 icount->overrun = cnow.overrun;
1137 icount->parity = cnow.parity;
1138 icount->brk = cnow.brk;
1139 icount->buf_overrun = cnow.buf_overrun;
1140
1141 return 0;
1142}
1143
1144/*
1145 * Called via sys_ioctl. We can use spin_lock_irq() here.
1146 */
1147static int
1148uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1149 unsigned long arg)
1150{
1151 struct uart_state *state = tty->driver_data;
1152 struct tty_port *port = &state->port;
1153 void __user *uarg = (void __user *)arg;
1154 int ret = -ENOIOCTLCMD;
1155
1156
1157 /*
1158 * These ioctls don't rely on the hardware to be present.
1159 */
1160 switch (cmd) {
1161 case TIOCGSERIAL:
1162 ret = uart_get_info_user(port, uarg);
1163 break;
1164
1165 case TIOCSSERIAL:
1166 ret = uart_set_info_user(tty, state, uarg);
1167 break;
1168
1169 case TIOCSERCONFIG:
1170 ret = uart_do_autoconfig(tty, state);
1171 break;
1172
1173 case TIOCSERGWILD: /* obsolete */
1174 case TIOCSERSWILD: /* obsolete */
1175 ret = 0;
1176 break;
1177 }
1178
1179 if (ret != -ENOIOCTLCMD)
1180 goto out;
1181
1182 if (tty->flags & (1 << TTY_IO_ERROR)) {
1183 ret = -EIO;
1184 goto out;
1185 }
1186
1187 /*
1188 * The following should only be used when hardware is present.
1189 */
1190 switch (cmd) {
1191 case TIOCMIWAIT:
1192 ret = uart_wait_modem_status(state, arg);
1193 break;
1194 }
1195
1196 if (ret != -ENOIOCTLCMD)
1197 goto out;
1198
1199 mutex_lock(&port->mutex);
1200
1201 if (tty->flags & (1 << TTY_IO_ERROR)) {
1202 ret = -EIO;
1203 goto out_up;
1204 }
1205
1206 /*
1207 * All these rely on hardware being present and need to be
1208 * protected against the tty being hung up.
1209 */
1210 switch (cmd) {
1211 case TIOCSERGETLSR: /* Get line status register */
1212 ret = uart_get_lsr_info(tty, state, uarg);
1213 break;
1214
1215 default: {
1216 struct uart_port *uport = state->uart_port;
1217 if (uport->ops->ioctl)
1218 ret = uport->ops->ioctl(uport, cmd, arg);
1219 break;
1220 }
1221 }
1222out_up:
1223 mutex_unlock(&port->mutex);
1224out:
1225 return ret;
1226}
1227
1228static void uart_set_ldisc(struct tty_struct *tty)
1229{
1230 struct uart_state *state = tty->driver_data;
1231 struct uart_port *uport = state->uart_port;
1232
1233 if (uport->ops->set_ldisc)
1234 uport->ops->set_ldisc(uport, tty->termios.c_line);
1235}
1236
1237static void uart_set_termios(struct tty_struct *tty,
1238 struct ktermios *old_termios)
1239{
1240 struct uart_state *state = tty->driver_data;
1241 struct uart_port *uport = state->uart_port;
1242 unsigned long flags;
1243 unsigned int cflag = tty->termios.c_cflag;
1244 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1245 bool sw_changed = false;
1246
1247 /*
1248 * Drivers doing software flow control also need to know
1249 * about changes to these input settings.
1250 */
1251 if (uport->flags & UPF_SOFT_FLOW) {
1252 iflag_mask |= IXANY|IXON|IXOFF;
1253 sw_changed =
1254 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1255 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1256 }
1257
1258 /*
1259 * These are the bits that are used to setup various
1260 * flags in the low level driver. We can ignore the Bfoo
1261 * bits in c_cflag; c_[io]speed will always be set
1262 * appropriately by set_termios() in tty_ioctl.c
1263 */
1264 if ((cflag ^ old_termios->c_cflag) == 0 &&
1265 tty->termios.c_ospeed == old_termios->c_ospeed &&
1266 tty->termios.c_ispeed == old_termios->c_ispeed &&
1267 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1268 !sw_changed) {
1269 return;
1270 }
1271
1272 uart_change_speed(tty, state, old_termios);
1273
1274 /* Handle transition to B0 status */
1275 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1276 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1277 /* Handle transition away from B0 status */
1278 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1279 unsigned int mask = TIOCM_DTR;
1280 if (!(cflag & CRTSCTS) ||
1281 !test_bit(TTY_THROTTLED, &tty->flags))
1282 mask |= TIOCM_RTS;
1283 uart_set_mctrl(uport, mask);
1284 }
1285
1286 /*
1287 * If the port is doing h/w assisted flow control, do nothing.
1288 * We assume that tty->hw_stopped has never been set.
1289 */
1290 if (uport->flags & UPF_HARD_FLOW)
1291 return;
1292
1293 /* Handle turning off CRTSCTS */
1294 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1295 spin_lock_irqsave(&uport->lock, flags);
1296 tty->hw_stopped = 0;
1297 __uart_start(tty);
1298 spin_unlock_irqrestore(&uport->lock, flags);
1299 }
1300 /* Handle turning on CRTSCTS */
1301 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1302 spin_lock_irqsave(&uport->lock, flags);
1303 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
1304 tty->hw_stopped = 1;
1305 uport->ops->stop_tx(uport);
1306 }
1307 spin_unlock_irqrestore(&uport->lock, flags);
1308 }
1309}
1310
1311/*
1312 * Calls to uart_close() are serialised via the tty_lock in
1313 * drivers/tty/tty_io.c:tty_release()
1314 * drivers/tty/tty_io.c:do_tty_hangup()
1315 * This runs from a workqueue and can sleep for a _short_ time only.
1316 */
1317static void uart_close(struct tty_struct *tty, struct file *filp)
1318{
1319 struct uart_state *state = tty->driver_data;
1320 struct tty_port *port;
1321 struct uart_port *uport;
1322 unsigned long flags;
1323
1324 if (!state)
1325 return;
1326
1327 uport = state->uart_port;
1328 port = &state->port;
1329
1330 pr_debug("uart_close(%d) called\n", uport ? uport->line : -1);
1331
1332 if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1333 return;
1334
1335 /*
1336 * At this point, we stop accepting input. To do this, we
1337 * disable the receive line status interrupts.
1338 */
1339 if (port->flags & ASYNC_INITIALIZED) {
1340 unsigned long flags;
1341 spin_lock_irqsave(&uport->lock, flags);
1342 uport->ops->stop_rx(uport);
1343 spin_unlock_irqrestore(&uport->lock, flags);
1344 /*
1345 * Before we drop DTR, make sure the UART transmitter
1346 * has completely drained; this is especially
1347 * important if there is a transmit FIFO!
1348 */
1349 uart_wait_until_sent(tty, uport->timeout);
1350 }
1351
1352 mutex_lock(&port->mutex);
1353 uart_shutdown(tty, state);
1354 uart_flush_buffer(tty);
1355
1356 tty_ldisc_flush(tty);
1357
1358 tty_port_tty_set(port, NULL);
1359 spin_lock_irqsave(&port->lock, flags);
1360 tty->closing = 0;
1361
1362 if (port->blocked_open) {
1363 spin_unlock_irqrestore(&port->lock, flags);
1364 if (port->close_delay)
1365 msleep_interruptible(
1366 jiffies_to_msecs(port->close_delay));
1367 spin_lock_irqsave(&port->lock, flags);
1368 } else if (!uart_console(uport)) {
1369 spin_unlock_irqrestore(&port->lock, flags);
1370 uart_change_pm(state, UART_PM_STATE_OFF);
1371 spin_lock_irqsave(&port->lock, flags);
1372 }
1373
1374 /*
1375 * Wake up anyone trying to open this port.
1376 */
1377 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1378 clear_bit(ASYNCB_CLOSING, &port->flags);
1379 spin_unlock_irqrestore(&port->lock, flags);
1380 wake_up_interruptible(&port->open_wait);
1381 wake_up_interruptible(&port->close_wait);
1382
1383 mutex_unlock(&port->mutex);
1384}
1385
1386static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1387{
1388 struct uart_state *state = tty->driver_data;
1389 struct uart_port *port = state->uart_port;
1390 unsigned long char_time, expire;
1391
1392 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1393 return;
1394
1395 /*
1396 * Set the check interval to be 1/5 of the estimated time to
1397 * send a single character, and make it at least 1. The check
1398 * interval should also be less than the timeout.
1399 *
1400 * Note: we have to use pretty tight timings here to satisfy
1401 * the NIST-PCTS.
1402 */
1403 char_time = (port->timeout - HZ/50) / port->fifosize;
1404 char_time = char_time / 5;
1405 if (char_time == 0)
1406 char_time = 1;
1407 if (timeout && timeout < char_time)
1408 char_time = timeout;
1409
1410 /*
1411 * If the transmitter hasn't cleared in twice the approximate
1412 * amount of time to send the entire FIFO, it probably won't
1413 * ever clear. This assumes the UART isn't doing flow
1414 * control, which is currently the case. Hence, if it ever
1415 * takes longer than port->timeout, this is probably due to a
1416 * UART bug of some kind. So, we clamp the timeout parameter at
1417 * 2*port->timeout.
1418 */
1419 if (timeout == 0 || timeout > 2 * port->timeout)
1420 timeout = 2 * port->timeout;
1421
1422 expire = jiffies + timeout;
1423
1424 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1425 port->line, jiffies, expire);
1426
1427 /*
1428 * Check whether the transmitter is empty every 'char_time'.
1429 * 'timeout' / 'expire' give us the maximum amount of time
1430 * we wait.
1431 */
1432 while (!port->ops->tx_empty(port)) {
1433 msleep_interruptible(jiffies_to_msecs(char_time));
1434 if (signal_pending(current))
1435 break;
1436 if (time_after(jiffies, expire))
1437 break;
1438 }
1439}
1440
1441/*
1442 * Calls to uart_hangup() are serialised by the tty_lock in
1443 * drivers/tty/tty_io.c:do_tty_hangup()
1444 * This runs from a workqueue and can sleep for a _short_ time only.
1445 */
1446static void uart_hangup(struct tty_struct *tty)
1447{
1448 struct uart_state *state = tty->driver_data;
1449 struct tty_port *port = &state->port;
1450 unsigned long flags;
1451
1452 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1453
1454 mutex_lock(&port->mutex);
1455 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1456 uart_flush_buffer(tty);
1457 uart_shutdown(tty, state);
1458 spin_lock_irqsave(&port->lock, flags);
1459 port->count = 0;
1460 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1461 spin_unlock_irqrestore(&port->lock, flags);
1462 tty_port_tty_set(port, NULL);
1463 if (!uart_console(state->uart_port))
1464 uart_change_pm(state, UART_PM_STATE_OFF);
1465 wake_up_interruptible(&port->open_wait);
1466 wake_up_interruptible(&port->delta_msr_wait);
1467 }
1468 mutex_unlock(&port->mutex);
1469}
1470
1471static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1472{
1473 return 0;
1474}
1475
1476static void uart_port_shutdown(struct tty_port *port)
1477{
1478 struct uart_state *state = container_of(port, struct uart_state, port);
1479 struct uart_port *uport = state->uart_port;
1480
1481 /*
1482 * clear delta_msr_wait queue to avoid mem leaks: we may free
1483 * the irq here so the queue might never be woken up. Note
1484 * that we won't end up waiting on delta_msr_wait again since
1485 * any outstanding file descriptors should be pointing at
1486 * hung_up_tty_fops now.
1487 */
1488 wake_up_interruptible(&port->delta_msr_wait);
1489
1490 /*
1491 * Free the IRQ and disable the port.
1492 */
1493 uport->ops->shutdown(uport);
1494
1495 /*
1496 * Ensure that the IRQ handler isn't running on another CPU.
1497 */
1498 synchronize_irq(uport->irq);
1499}
1500
1501static int uart_carrier_raised(struct tty_port *port)
1502{
1503 struct uart_state *state = container_of(port, struct uart_state, port);
1504 struct uart_port *uport = state->uart_port;
1505 int mctrl;
1506 spin_lock_irq(&uport->lock);
1507 uport->ops->enable_ms(uport);
1508 mctrl = uport->ops->get_mctrl(uport);
1509 spin_unlock_irq(&uport->lock);
1510 if (mctrl & TIOCM_CAR)
1511 return 1;
1512 return 0;
1513}
1514
1515static void uart_dtr_rts(struct tty_port *port, int onoff)
1516{
1517 struct uart_state *state = container_of(port, struct uart_state, port);
1518 struct uart_port *uport = state->uart_port;
1519
1520 if (onoff)
1521 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1522 else
1523 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1524}
1525
1526/*
1527 * Calls to uart_open are serialised by the tty_lock in
1528 * drivers/tty/tty_io.c:tty_open()
1529 * Note that if this fails, then uart_close() _will_ be called.
1530 *
1531 * In time, we want to scrap the "opening nonpresent ports"
1532 * behaviour and implement an alternative way for setserial
1533 * to set base addresses/ports/types. This will allow us to
1534 * get rid of a certain amount of extra tests.
1535 */
1536static int uart_open(struct tty_struct *tty, struct file *filp)
1537{
1538 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1539 int retval, line = tty->index;
1540 struct uart_state *state = drv->state + line;
1541 struct tty_port *port = &state->port;
1542
1543 pr_debug("uart_open(%d) called\n", line);
1544
1545 /*
1546 * We take the semaphore here to guarantee that we won't be re-entered
1547 * while allocating the state structure, or while we request any IRQs
1548 * that the driver may need. This also has the nice side-effect that
1549 * it delays the action of uart_hangup, so we can guarantee that
1550 * state->port.tty will always contain something reasonable.
1551 */
1552 if (mutex_lock_interruptible(&port->mutex)) {
1553 retval = -ERESTARTSYS;
1554 goto end;
1555 }
1556
1557 port->count++;
1558 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1559 retval = -ENXIO;
1560 goto err_dec_count;
1561 }
1562
1563 /*
1564 * Once we set tty->driver_data here, we are guaranteed that
1565 * uart_close() will decrement the driver module use count.
1566 * Any failures from here onwards should not touch the count.
1567 */
1568 tty->driver_data = state;
1569 state->uart_port->state = state;
1570 state->port.low_latency =
1571 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1572 tty_port_tty_set(port, tty);
1573
1574 /*
1575 * If the port is in the middle of closing, bail out now.
1576 */
1577 if (tty_hung_up_p(filp)) {
1578 retval = -EAGAIN;
1579 goto err_dec_count;
1580 }
1581
1582 /*
1583 * Start up the serial port.
1584 */
1585 retval = uart_startup(tty, state, 0);
1586
1587 /*
1588 * If we succeeded, wait until the port is ready.
1589 */
1590 mutex_unlock(&port->mutex);
1591 if (retval == 0)
1592 retval = tty_port_block_til_ready(port, tty, filp);
1593
1594end:
1595 return retval;
1596err_dec_count:
1597 port->count--;
1598 mutex_unlock(&port->mutex);
1599 goto end;
1600}
1601
1602static const char *uart_type(struct uart_port *port)
1603{
1604 const char *str = NULL;
1605
1606 if (port->ops->type)
1607 str = port->ops->type(port);
1608
1609 if (!str)
1610 str = "unknown";
1611
1612 return str;
1613}
1614
1615#ifdef CONFIG_PROC_FS
1616
1617static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1618{
1619 struct uart_state *state = drv->state + i;
1620 struct tty_port *port = &state->port;
1621 enum uart_pm_state pm_state;
1622 struct uart_port *uport = state->uart_port;
1623 char stat_buf[32];
1624 unsigned int status;
1625 int mmio;
1626
1627 if (!uport)
1628 return;
1629
1630 mmio = uport->iotype >= UPIO_MEM;
1631 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1632 uport->line, uart_type(uport),
1633 mmio ? "mmio:0x" : "port:",
1634 mmio ? (unsigned long long)uport->mapbase
1635 : (unsigned long long)uport->iobase,
1636 uport->irq);
1637
1638 if (uport->type == PORT_UNKNOWN) {
1639 seq_putc(m, '\n');
1640 return;
1641 }
1642
1643 if (capable(CAP_SYS_ADMIN)) {
1644 mutex_lock(&port->mutex);
1645 pm_state = state->pm_state;
1646 if (pm_state != UART_PM_STATE_ON)
1647 uart_change_pm(state, UART_PM_STATE_ON);
1648 spin_lock_irq(&uport->lock);
1649 status = uport->ops->get_mctrl(uport);
1650 spin_unlock_irq(&uport->lock);
1651 if (pm_state != UART_PM_STATE_ON)
1652 uart_change_pm(state, pm_state);
1653 mutex_unlock(&port->mutex);
1654
1655 seq_printf(m, " tx:%d rx:%d",
1656 uport->icount.tx, uport->icount.rx);
1657 if (uport->icount.frame)
1658 seq_printf(m, " fe:%d",
1659 uport->icount.frame);
1660 if (uport->icount.parity)
1661 seq_printf(m, " pe:%d",
1662 uport->icount.parity);
1663 if (uport->icount.brk)
1664 seq_printf(m, " brk:%d",
1665 uport->icount.brk);
1666 if (uport->icount.overrun)
1667 seq_printf(m, " oe:%d",
1668 uport->icount.overrun);
1669
1670#define INFOBIT(bit, str) \
1671 if (uport->mctrl & (bit)) \
1672 strncat(stat_buf, (str), sizeof(stat_buf) - \
1673 strlen(stat_buf) - 2)
1674#define STATBIT(bit, str) \
1675 if (status & (bit)) \
1676 strncat(stat_buf, (str), sizeof(stat_buf) - \
1677 strlen(stat_buf) - 2)
1678
1679 stat_buf[0] = '\0';
1680 stat_buf[1] = '\0';
1681 INFOBIT(TIOCM_RTS, "|RTS");
1682 STATBIT(TIOCM_CTS, "|CTS");
1683 INFOBIT(TIOCM_DTR, "|DTR");
1684 STATBIT(TIOCM_DSR, "|DSR");
1685 STATBIT(TIOCM_CAR, "|CD");
1686 STATBIT(TIOCM_RNG, "|RI");
1687 if (stat_buf[0])
1688 stat_buf[0] = ' ';
1689
1690 seq_puts(m, stat_buf);
1691 }
1692 seq_putc(m, '\n');
1693#undef STATBIT
1694#undef INFOBIT
1695}
1696
1697static int uart_proc_show(struct seq_file *m, void *v)
1698{
1699 struct tty_driver *ttydrv = m->private;
1700 struct uart_driver *drv = ttydrv->driver_state;
1701 int i;
1702
1703 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1704 "", "", "");
1705 for (i = 0; i < drv->nr; i++)
1706 uart_line_info(m, drv, i);
1707 return 0;
1708}
1709
1710static int uart_proc_open(struct inode *inode, struct file *file)
1711{
1712 return single_open(file, uart_proc_show, PDE_DATA(inode));
1713}
1714
1715static const struct file_operations uart_proc_fops = {
1716 .owner = THIS_MODULE,
1717 .open = uart_proc_open,
1718 .read = seq_read,
1719 .llseek = seq_lseek,
1720 .release = single_release,
1721};
1722#endif
1723
1724#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1725/*
1726 * uart_console_write - write a console message to a serial port
1727 * @port: the port to write the message
1728 * @s: array of characters
1729 * @count: number of characters in string to write
1730 * @write: function to write character to port
1731 */
1732void uart_console_write(struct uart_port *port, const char *s,
1733 unsigned int count,
1734 void (*putchar)(struct uart_port *, int))
1735{
1736 unsigned int i;
1737
1738 for (i = 0; i < count; i++, s++) {
1739 if (*s == '\n')
1740 putchar(port, '\r');
1741 putchar(port, *s);
1742 }
1743}
1744EXPORT_SYMBOL_GPL(uart_console_write);
1745
1746/*
1747 * Check whether an invalid uart number has been specified, and
1748 * if so, search for the first available port that does have
1749 * console support.
1750 */
1751struct uart_port * __init
1752uart_get_console(struct uart_port *ports, int nr, struct console *co)
1753{
1754 int idx = co->index;
1755
1756 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1757 ports[idx].membase == NULL))
1758 for (idx = 0; idx < nr; idx++)
1759 if (ports[idx].iobase != 0 ||
1760 ports[idx].membase != NULL)
1761 break;
1762
1763 co->index = idx;
1764
1765 return ports + idx;
1766}
1767
1768/**
1769 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1770 * @options: pointer to option string
1771 * @baud: pointer to an 'int' variable for the baud rate.
1772 * @parity: pointer to an 'int' variable for the parity.
1773 * @bits: pointer to an 'int' variable for the number of data bits.
1774 * @flow: pointer to an 'int' variable for the flow control character.
1775 *
1776 * uart_parse_options decodes a string containing the serial console
1777 * options. The format of the string is <baud><parity><bits><flow>,
1778 * eg: 115200n8r
1779 */
1780void
1781uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1782{
1783 char *s = options;
1784
1785 *baud = simple_strtoul(s, NULL, 10);
1786 while (*s >= '0' && *s <= '9')
1787 s++;
1788 if (*s)
1789 *parity = *s++;
1790 if (*s)
1791 *bits = *s++ - '0';
1792 if (*s)
1793 *flow = *s;
1794}
1795EXPORT_SYMBOL_GPL(uart_parse_options);
1796
1797struct baud_rates {
1798 unsigned int rate;
1799 unsigned int cflag;
1800};
1801
1802static const struct baud_rates baud_rates[] = {
1803 { 921600, B921600 },
1804 { 460800, B460800 },
1805 { 230400, B230400 },
1806 { 115200, B115200 },
1807 { 57600, B57600 },
1808 { 38400, B38400 },
1809 { 19200, B19200 },
1810 { 9600, B9600 },
1811 { 4800, B4800 },
1812 { 2400, B2400 },
1813 { 1200, B1200 },
1814 { 0, B38400 }
1815};
1816
1817/**
1818 * uart_set_options - setup the serial console parameters
1819 * @port: pointer to the serial ports uart_port structure
1820 * @co: console pointer
1821 * @baud: baud rate
1822 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1823 * @bits: number of data bits
1824 * @flow: flow control character - 'r' (rts)
1825 */
1826int
1827uart_set_options(struct uart_port *port, struct console *co,
1828 int baud, int parity, int bits, int flow)
1829{
1830 struct ktermios termios;
1831 static struct ktermios dummy;
1832 int i;
1833
1834 /*
1835 * Ensure that the serial console lock is initialised
1836 * early.
1837 * If this port is a console, then the spinlock is already
1838 * initialised.
1839 */
1840 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1841 spin_lock_init(&port->lock);
1842 lockdep_set_class(&port->lock, &port_lock_key);
1843 }
1844
1845 memset(&termios, 0, sizeof(struct ktermios));
1846
1847 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1848
1849 /*
1850 * Construct a cflag setting.
1851 */
1852 for (i = 0; baud_rates[i].rate; i++)
1853 if (baud_rates[i].rate <= baud)
1854 break;
1855
1856 termios.c_cflag |= baud_rates[i].cflag;
1857
1858 if (bits == 7)
1859 termios.c_cflag |= CS7;
1860 else
1861 termios.c_cflag |= CS8;
1862
1863 switch (parity) {
1864 case 'o': case 'O':
1865 termios.c_cflag |= PARODD;
1866 /*fall through*/
1867 case 'e': case 'E':
1868 termios.c_cflag |= PARENB;
1869 break;
1870 }
1871
1872 if (flow == 'r')
1873 termios.c_cflag |= CRTSCTS;
1874
1875 /*
1876 * some uarts on other side don't support no flow control.
1877 * So we set * DTR in host uart to make them happy
1878 */
1879 port->mctrl |= TIOCM_DTR;
1880
1881 port->ops->set_termios(port, &termios, &dummy);
1882 /*
1883 * Allow the setting of the UART parameters with a NULL console
1884 * too:
1885 */
1886 if (co)
1887 co->cflag = termios.c_cflag;
1888
1889 return 0;
1890}
1891EXPORT_SYMBOL_GPL(uart_set_options);
1892#endif /* CONFIG_SERIAL_CORE_CONSOLE */
1893
1894/**
1895 * uart_change_pm - set power state of the port
1896 *
1897 * @state: port descriptor
1898 * @pm_state: new state
1899 *
1900 * Locking: port->mutex has to be held
1901 */
1902static void uart_change_pm(struct uart_state *state,
1903 enum uart_pm_state pm_state)
1904{
1905 struct uart_port *port = state->uart_port;
1906
1907 if (state->pm_state != pm_state) {
1908 if (port->ops->pm)
1909 port->ops->pm(port, pm_state, state->pm_state);
1910 state->pm_state = pm_state;
1911 }
1912}
1913
1914struct uart_match {
1915 struct uart_port *port;
1916 struct uart_driver *driver;
1917};
1918
1919static int serial_match_port(struct device *dev, void *data)
1920{
1921 struct uart_match *match = data;
1922 struct tty_driver *tty_drv = match->driver->tty_driver;
1923 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1924 match->port->line;
1925
1926 return dev->devt == devt; /* Actually, only one tty per port */
1927}
1928
1929int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1930{
1931 struct uart_state *state = drv->state + uport->line;
1932 struct tty_port *port = &state->port;
1933 struct device *tty_dev;
1934 struct uart_match match = {uport, drv};
1935
1936 mutex_lock(&port->mutex);
1937
1938 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1939 if (device_may_wakeup(tty_dev)) {
1940 if (!enable_irq_wake(uport->irq))
1941 uport->irq_wake = 1;
1942 put_device(tty_dev);
1943 mutex_unlock(&port->mutex);
1944 return 0;
1945 }
1946 put_device(tty_dev);
1947
1948 if (console_suspend_enabled || !uart_console(uport))
1949 uport->suspended = 1;
1950
1951 if (port->flags & ASYNC_INITIALIZED) {
1952 const struct uart_ops *ops = uport->ops;
1953 int tries;
1954
1955 if (console_suspend_enabled || !uart_console(uport)) {
1956 set_bit(ASYNCB_SUSPENDED, &port->flags);
1957 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1958
1959 spin_lock_irq(&uport->lock);
1960 ops->stop_tx(uport);
1961 ops->set_mctrl(uport, 0);
1962 ops->stop_rx(uport);
1963 spin_unlock_irq(&uport->lock);
1964 }
1965
1966 /*
1967 * Wait for the transmitter to empty.
1968 */
1969 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1970 msleep(10);
1971 if (!tries)
1972 printk(KERN_ERR "%s%s%s%d: Unable to drain "
1973 "transmitter\n",
1974 uport->dev ? dev_name(uport->dev) : "",
1975 uport->dev ? ": " : "",
1976 drv->dev_name,
1977 drv->tty_driver->name_base + uport->line);
1978
1979 if (console_suspend_enabled || !uart_console(uport))
1980 ops->shutdown(uport);
1981 }
1982
1983 /*
1984 * Disable the console device before suspending.
1985 */
1986 if (console_suspend_enabled && uart_console(uport))
1987 console_stop(uport->cons);
1988
1989 if (console_suspend_enabled || !uart_console(uport))
1990 uart_change_pm(state, UART_PM_STATE_OFF);
1991
1992 mutex_unlock(&port->mutex);
1993
1994 return 0;
1995}
1996
1997int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1998{
1999 struct uart_state *state = drv->state + uport->line;
2000 struct tty_port *port = &state->port;
2001 struct device *tty_dev;
2002 struct uart_match match = {uport, drv};
2003 struct ktermios termios;
2004
2005 mutex_lock(&port->mutex);
2006
2007 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2008 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2009 if (uport->irq_wake) {
2010 disable_irq_wake(uport->irq);
2011 uport->irq_wake = 0;
2012 }
2013 put_device(tty_dev);
2014 mutex_unlock(&port->mutex);
2015 return 0;
2016 }
2017 put_device(tty_dev);
2018 uport->suspended = 0;
2019
2020 /*
2021 * Re-enable the console device after suspending.
2022 */
2023 if (uart_console(uport)) {
2024 /*
2025 * First try to use the console cflag setting.
2026 */
2027 memset(&termios, 0, sizeof(struct ktermios));
2028 termios.c_cflag = uport->cons->cflag;
2029
2030 /*
2031 * If that's unset, use the tty termios setting.
2032 */
2033 if (port->tty && termios.c_cflag == 0)
2034 termios = port->tty->termios;
2035
2036 if (console_suspend_enabled)
2037 uart_change_pm(state, UART_PM_STATE_ON);
2038 uport->ops->set_termios(uport, &termios, NULL);
2039 if (console_suspend_enabled)
2040 console_start(uport->cons);
2041 }
2042
2043 if (port->flags & ASYNC_SUSPENDED) {
2044 const struct uart_ops *ops = uport->ops;
2045 int ret;
2046
2047 uart_change_pm(state, UART_PM_STATE_ON);
2048 spin_lock_irq(&uport->lock);
2049 ops->set_mctrl(uport, 0);
2050 spin_unlock_irq(&uport->lock);
2051 if (console_suspend_enabled || !uart_console(uport)) {
2052 /* Protected by port mutex for now */
2053 struct tty_struct *tty = port->tty;
2054 ret = ops->startup(uport);
2055 if (ret == 0) {
2056 if (tty)
2057 uart_change_speed(tty, state, NULL);
2058 spin_lock_irq(&uport->lock);
2059 ops->set_mctrl(uport, uport->mctrl);
2060 ops->start_tx(uport);
2061 spin_unlock_irq(&uport->lock);
2062 set_bit(ASYNCB_INITIALIZED, &port->flags);
2063 } else {
2064 /*
2065 * Failed to resume - maybe hardware went away?
2066 * Clear the "initialized" flag so we won't try
2067 * to call the low level drivers shutdown method.
2068 */
2069 uart_shutdown(tty, state);
2070 }
2071 }
2072
2073 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2074 }
2075
2076 mutex_unlock(&port->mutex);
2077
2078 return 0;
2079}
2080
2081static inline void
2082uart_report_port(struct uart_driver *drv, struct uart_port *port)
2083{
2084 char address[64];
2085
2086 switch (port->iotype) {
2087 case UPIO_PORT:
2088 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2089 break;
2090 case UPIO_HUB6:
2091 snprintf(address, sizeof(address),
2092 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2093 break;
2094 case UPIO_MEM:
2095 case UPIO_MEM32:
2096 case UPIO_AU:
2097 case UPIO_TSI:
2098 snprintf(address, sizeof(address),
2099 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2100 break;
2101 default:
2102 strlcpy(address, "*unknown*", sizeof(address));
2103 break;
2104 }
2105
2106 printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2107 port->dev ? dev_name(port->dev) : "",
2108 port->dev ? ": " : "",
2109 drv->dev_name,
2110 drv->tty_driver->name_base + port->line,
2111 address, port->irq, port->uartclk / 16, uart_type(port));
2112}
2113
2114static void
2115uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2116 struct uart_port *port)
2117{
2118 unsigned int flags;
2119
2120 /*
2121 * If there isn't a port here, don't do anything further.
2122 */
2123 if (!port->iobase && !port->mapbase && !port->membase)
2124 return;
2125
2126 /*
2127 * Now do the auto configuration stuff. Note that config_port
2128 * is expected to claim the resources and map the port for us.
2129 */
2130 flags = 0;
2131 if (port->flags & UPF_AUTO_IRQ)
2132 flags |= UART_CONFIG_IRQ;
2133 if (port->flags & UPF_BOOT_AUTOCONF) {
2134 if (!(port->flags & UPF_FIXED_TYPE)) {
2135 port->type = PORT_UNKNOWN;
2136 flags |= UART_CONFIG_TYPE;
2137 }
2138 port->ops->config_port(port, flags);
2139 }
2140
2141 if (port->type != PORT_UNKNOWN) {
2142 unsigned long flags;
2143
2144 uart_report_port(drv, port);
2145
2146 /* Power up port for set_mctrl() */
2147 uart_change_pm(state, UART_PM_STATE_ON);
2148
2149 /*
2150 * Ensure that the modem control lines are de-activated.
2151 * keep the DTR setting that is set in uart_set_options()
2152 * We probably don't need a spinlock around this, but
2153 */
2154 spin_lock_irqsave(&port->lock, flags);
2155 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2156 spin_unlock_irqrestore(&port->lock, flags);
2157
2158 /*
2159 * If this driver supports console, and it hasn't been
2160 * successfully registered yet, try to re-register it.
2161 * It may be that the port was not available.
2162 */
2163 if (port->cons && !(port->cons->flags & CON_ENABLED))
2164 register_console(port->cons);
2165
2166 /*
2167 * Power down all ports by default, except the
2168 * console if we have one.
2169 */
2170 if (!uart_console(port))
2171 uart_change_pm(state, UART_PM_STATE_OFF);
2172 }
2173}
2174
2175#ifdef CONFIG_CONSOLE_POLL
2176
2177static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2178{
2179 struct uart_driver *drv = driver->driver_state;
2180 struct uart_state *state = drv->state + line;
2181 struct uart_port *port;
2182 int baud = 9600;
2183 int bits = 8;
2184 int parity = 'n';
2185 int flow = 'n';
2186 int ret;
2187
2188 if (!state || !state->uart_port)
2189 return -1;
2190
2191 port = state->uart_port;
2192 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2193 return -1;
2194
2195 if (port->ops->poll_init) {
2196 struct tty_port *tport = &state->port;
2197
2198 ret = 0;
2199 mutex_lock(&tport->mutex);
2200 /*
2201 * We don't set ASYNCB_INITIALIZED as we only initialized the
2202 * hw, e.g. state->xmit is still uninitialized.
2203 */
2204 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2205 ret = port->ops->poll_init(port);
2206 mutex_unlock(&tport->mutex);
2207 if (ret)
2208 return ret;
2209 }
2210
2211 if (options) {
2212 uart_parse_options(options, &baud, &parity, &bits, &flow);
2213 return uart_set_options(port, NULL, baud, parity, bits, flow);
2214 }
2215
2216 return 0;
2217}
2218
2219static int uart_poll_get_char(struct tty_driver *driver, int line)
2220{
2221 struct uart_driver *drv = driver->driver_state;
2222 struct uart_state *state = drv->state + line;
2223 struct uart_port *port;
2224
2225 if (!state || !state->uart_port)
2226 return -1;
2227
2228 port = state->uart_port;
2229 return port->ops->poll_get_char(port);
2230}
2231
2232static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2233{
2234 struct uart_driver *drv = driver->driver_state;
2235 struct uart_state *state = drv->state + line;
2236 struct uart_port *port;
2237
2238 if (!state || !state->uart_port)
2239 return;
2240
2241 port = state->uart_port;
2242 port->ops->poll_put_char(port, ch);
2243}
2244#endif
2245
2246static const struct tty_operations uart_ops = {
2247 .open = uart_open,
2248 .close = uart_close,
2249 .write = uart_write,
2250 .put_char = uart_put_char,
2251 .flush_chars = uart_flush_chars,
2252 .write_room = uart_write_room,
2253 .chars_in_buffer= uart_chars_in_buffer,
2254 .flush_buffer = uart_flush_buffer,
2255 .ioctl = uart_ioctl,
2256 .throttle = uart_throttle,
2257 .unthrottle = uart_unthrottle,
2258 .send_xchar = uart_send_xchar,
2259 .set_termios = uart_set_termios,
2260 .set_ldisc = uart_set_ldisc,
2261 .stop = uart_stop,
2262 .start = uart_start,
2263 .hangup = uart_hangup,
2264 .break_ctl = uart_break_ctl,
2265 .wait_until_sent= uart_wait_until_sent,
2266#ifdef CONFIG_PROC_FS
2267 .proc_fops = &uart_proc_fops,
2268#endif
2269 .tiocmget = uart_tiocmget,
2270 .tiocmset = uart_tiocmset,
2271 .get_icount = uart_get_icount,
2272#ifdef CONFIG_CONSOLE_POLL
2273 .poll_init = uart_poll_init,
2274 .poll_get_char = uart_poll_get_char,
2275 .poll_put_char = uart_poll_put_char,
2276#endif
2277};
2278
2279static const struct tty_port_operations uart_port_ops = {
2280 .activate = uart_port_activate,
2281 .shutdown = uart_port_shutdown,
2282 .carrier_raised = uart_carrier_raised,
2283 .dtr_rts = uart_dtr_rts,
2284};
2285
2286/**
2287 * uart_register_driver - register a driver with the uart core layer
2288 * @drv: low level driver structure
2289 *
2290 * Register a uart driver with the core driver. We in turn register
2291 * with the tty layer, and initialise the core driver per-port state.
2292 *
2293 * We have a proc file in /proc/tty/driver which is named after the
2294 * normal driver.
2295 *
2296 * drv->port should be NULL, and the per-port structures should be
2297 * registered using uart_add_one_port after this call has succeeded.
2298 */
2299int uart_register_driver(struct uart_driver *drv)
2300{
2301 struct tty_driver *normal;
2302 int i, retval;
2303
2304 BUG_ON(drv->state);
2305
2306 /*
2307 * Maybe we should be using a slab cache for this, especially if
2308 * we have a large number of ports to handle.
2309 */
2310 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2311 if (!drv->state)
2312 goto out;
2313
2314 normal = alloc_tty_driver(drv->nr);
2315 if (!normal)
2316 goto out_kfree;
2317
2318 drv->tty_driver = normal;
2319
2320 normal->driver_name = drv->driver_name;
2321 normal->name = drv->dev_name;
2322 normal->major = drv->major;
2323 normal->minor_start = drv->minor;
2324 normal->type = TTY_DRIVER_TYPE_SERIAL;
2325 normal->subtype = SERIAL_TYPE_NORMAL;
2326 normal->init_termios = tty_std_termios;
2327 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2328 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2329 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2330 normal->driver_state = drv;
2331 tty_set_operations(normal, &uart_ops);
2332
2333 /*
2334 * Initialise the UART state(s).
2335 */
2336 for (i = 0; i < drv->nr; i++) {
2337 struct uart_state *state = drv->state + i;
2338 struct tty_port *port = &state->port;
2339
2340 tty_port_init(port);
2341 port->ops = &uart_port_ops;
2342 port->close_delay = HZ / 2; /* .5 seconds */
2343 port->closing_wait = 30 * HZ;/* 30 seconds */
2344 }
2345
2346 retval = tty_register_driver(normal);
2347 if (retval >= 0)
2348 return retval;
2349
2350 for (i = 0; i < drv->nr; i++)
2351 tty_port_destroy(&drv->state[i].port);
2352 put_tty_driver(normal);
2353out_kfree:
2354 kfree(drv->state);
2355out:
2356 return -ENOMEM;
2357}
2358
2359/**
2360 * uart_unregister_driver - remove a driver from the uart core layer
2361 * @drv: low level driver structure
2362 *
2363 * Remove all references to a driver from the core driver. The low
2364 * level driver must have removed all its ports via the
2365 * uart_remove_one_port() if it registered them with uart_add_one_port().
2366 * (ie, drv->port == NULL)
2367 */
2368void uart_unregister_driver(struct uart_driver *drv)
2369{
2370 struct tty_driver *p = drv->tty_driver;
2371 unsigned int i;
2372
2373 tty_unregister_driver(p);
2374 put_tty_driver(p);
2375 for (i = 0; i < drv->nr; i++)
2376 tty_port_destroy(&drv->state[i].port);
2377 kfree(drv->state);
2378 drv->state = NULL;
2379 drv->tty_driver = NULL;
2380}
2381
2382struct tty_driver *uart_console_device(struct console *co, int *index)
2383{
2384 struct uart_driver *p = co->data;
2385 *index = co->index;
2386 return p->tty_driver;
2387}
2388
2389static ssize_t uart_get_attr_uartclk(struct device *dev,
2390 struct device_attribute *attr, char *buf)
2391{
2392 struct serial_struct tmp;
2393 struct tty_port *port = dev_get_drvdata(dev);
2394
2395 uart_get_info(port, &tmp);
2396 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2397}
2398
2399static ssize_t uart_get_attr_type(struct device *dev,
2400 struct device_attribute *attr, char *buf)
2401{
2402 struct serial_struct tmp;
2403 struct tty_port *port = dev_get_drvdata(dev);
2404
2405 uart_get_info(port, &tmp);
2406 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2407}
2408static ssize_t uart_get_attr_line(struct device *dev,
2409 struct device_attribute *attr, char *buf)
2410{
2411 struct serial_struct tmp;
2412 struct tty_port *port = dev_get_drvdata(dev);
2413
2414 uart_get_info(port, &tmp);
2415 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2416}
2417
2418static ssize_t uart_get_attr_port(struct device *dev,
2419 struct device_attribute *attr, char *buf)
2420{
2421 struct serial_struct tmp;
2422 struct tty_port *port = dev_get_drvdata(dev);
2423 unsigned long ioaddr;
2424
2425 uart_get_info(port, &tmp);
2426 ioaddr = tmp.port;
2427 if (HIGH_BITS_OFFSET)
2428 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2429 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2430}
2431
2432static ssize_t uart_get_attr_irq(struct device *dev,
2433 struct device_attribute *attr, char *buf)
2434{
2435 struct serial_struct tmp;
2436 struct tty_port *port = dev_get_drvdata(dev);
2437
2438 uart_get_info(port, &tmp);
2439 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2440}
2441
2442static ssize_t uart_get_attr_flags(struct device *dev,
2443 struct device_attribute *attr, char *buf)
2444{
2445 struct serial_struct tmp;
2446 struct tty_port *port = dev_get_drvdata(dev);
2447
2448 uart_get_info(port, &tmp);
2449 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2450}
2451
2452static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2453 struct device_attribute *attr, char *buf)
2454{
2455 struct serial_struct tmp;
2456 struct tty_port *port = dev_get_drvdata(dev);
2457
2458 uart_get_info(port, &tmp);
2459 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2460}
2461
2462
2463static ssize_t uart_get_attr_close_delay(struct device *dev,
2464 struct device_attribute *attr, char *buf)
2465{
2466 struct serial_struct tmp;
2467 struct tty_port *port = dev_get_drvdata(dev);
2468
2469 uart_get_info(port, &tmp);
2470 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2471}
2472
2473
2474static ssize_t uart_get_attr_closing_wait(struct device *dev,
2475 struct device_attribute *attr, char *buf)
2476{
2477 struct serial_struct tmp;
2478 struct tty_port *port = dev_get_drvdata(dev);
2479
2480 uart_get_info(port, &tmp);
2481 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2482}
2483
2484static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2485 struct device_attribute *attr, char *buf)
2486{
2487 struct serial_struct tmp;
2488 struct tty_port *port = dev_get_drvdata(dev);
2489
2490 uart_get_info(port, &tmp);
2491 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2492}
2493
2494static ssize_t uart_get_attr_io_type(struct device *dev,
2495 struct device_attribute *attr, char *buf)
2496{
2497 struct serial_struct tmp;
2498 struct tty_port *port = dev_get_drvdata(dev);
2499
2500 uart_get_info(port, &tmp);
2501 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2502}
2503
2504static ssize_t uart_get_attr_iomem_base(struct device *dev,
2505 struct device_attribute *attr, char *buf)
2506{
2507 struct serial_struct tmp;
2508 struct tty_port *port = dev_get_drvdata(dev);
2509
2510 uart_get_info(port, &tmp);
2511 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2512}
2513
2514static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2515 struct device_attribute *attr, char *buf)
2516{
2517 struct serial_struct tmp;
2518 struct tty_port *port = dev_get_drvdata(dev);
2519
2520 uart_get_info(port, &tmp);
2521 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2522}
2523
2524static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2525static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2526static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2527static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2528static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2529static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2530static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2531static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2532static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2533static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2534static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2535static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2536static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2537
2538static struct attribute *tty_dev_attrs[] = {
2539 &dev_attr_type.attr,
2540 &dev_attr_line.attr,
2541 &dev_attr_port.attr,
2542 &dev_attr_irq.attr,
2543 &dev_attr_flags.attr,
2544 &dev_attr_xmit_fifo_size.attr,
2545 &dev_attr_uartclk.attr,
2546 &dev_attr_close_delay.attr,
2547 &dev_attr_closing_wait.attr,
2548 &dev_attr_custom_divisor.attr,
2549 &dev_attr_io_type.attr,
2550 &dev_attr_iomem_base.attr,
2551 &dev_attr_iomem_reg_shift.attr,
2552 NULL,
2553 };
2554
2555static const struct attribute_group tty_dev_attr_group = {
2556 .attrs = tty_dev_attrs,
2557 };
2558
2559static const struct attribute_group *tty_dev_attr_groups[] = {
2560 &tty_dev_attr_group,
2561 NULL
2562 };
2563
2564
2565/**
2566 * uart_add_one_port - attach a driver-defined port structure
2567 * @drv: pointer to the uart low level driver structure for this port
2568 * @uport: uart port structure to use for this port.
2569 *
2570 * This allows the driver to register its own uart_port structure
2571 * with the core driver. The main purpose is to allow the low
2572 * level uart drivers to expand uart_port, rather than having yet
2573 * more levels of structures.
2574 */
2575int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2576{
2577 struct uart_state *state;
2578 struct tty_port *port;
2579 int ret = 0;
2580 struct device *tty_dev;
2581
2582 BUG_ON(in_interrupt());
2583
2584 if (uport->line >= drv->nr)
2585 return -EINVAL;
2586
2587 state = drv->state + uport->line;
2588 port = &state->port;
2589
2590 mutex_lock(&port_mutex);
2591 mutex_lock(&port->mutex);
2592 if (state->uart_port) {
2593 ret = -EINVAL;
2594 goto out;
2595 }
2596
2597 state->uart_port = uport;
2598 state->pm_state = UART_PM_STATE_UNDEFINED;
2599
2600 uport->cons = drv->cons;
2601 uport->state = state;
2602
2603 /*
2604 * If this port is a console, then the spinlock is already
2605 * initialised.
2606 */
2607 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2608 spin_lock_init(&uport->lock);
2609 lockdep_set_class(&uport->lock, &port_lock_key);
2610 }
2611
2612 uart_configure_port(drv, state, uport);
2613
2614 /*
2615 * Register the port whether it's detected or not. This allows
2616 * setserial to be used to alter this port's parameters.
2617 */
2618 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2619 uport->line, uport->dev, port, tty_dev_attr_groups);
2620 if (likely(!IS_ERR(tty_dev))) {
2621 device_set_wakeup_capable(tty_dev, 1);
2622 } else {
2623 printk(KERN_ERR "Cannot register tty device on line %d\n",
2624 uport->line);
2625 }
2626
2627 /*
2628 * Ensure UPF_DEAD is not set.
2629 */
2630 uport->flags &= ~UPF_DEAD;
2631
2632 out:
2633 mutex_unlock(&port->mutex);
2634 mutex_unlock(&port_mutex);
2635
2636 return ret;
2637}
2638
2639/**
2640 * uart_remove_one_port - detach a driver defined port structure
2641 * @drv: pointer to the uart low level driver structure for this port
2642 * @uport: uart port structure for this port
2643 *
2644 * This unhooks (and hangs up) the specified port structure from the
2645 * core driver. No further calls will be made to the low-level code
2646 * for this port.
2647 */
2648int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2649{
2650 struct uart_state *state = drv->state + uport->line;
2651 struct tty_port *port = &state->port;
2652 struct tty_struct *tty;
2653 int ret = 0;
2654
2655 BUG_ON(in_interrupt());
2656
2657 if (state->uart_port != uport)
2658 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2659 state->uart_port, uport);
2660
2661 mutex_lock(&port_mutex);
2662
2663 /*
2664 * Mark the port "dead" - this prevents any opens from
2665 * succeeding while we shut down the port.
2666 */
2667 mutex_lock(&port->mutex);
2668 if (!state->uart_port) {
2669 mutex_unlock(&port->mutex);
2670 ret = -EINVAL;
2671 goto out;
2672 }
2673 uport->flags |= UPF_DEAD;
2674 mutex_unlock(&port->mutex);
2675
2676 /*
2677 * Remove the devices from the tty layer
2678 */
2679 tty_unregister_device(drv->tty_driver, uport->line);
2680
2681 tty = tty_port_tty_get(port);
2682 if (tty) {
2683 tty_vhangup(port->tty);
2684 tty_kref_put(tty);
2685 }
2686
2687 /*
2688 * If the port is used as a console, unregister it
2689 */
2690 if (uart_console(uport))
2691 unregister_console(uport->cons);
2692
2693 /*
2694 * Free the port IO and memory resources, if any.
2695 */
2696 if (uport->type != PORT_UNKNOWN)
2697 uport->ops->release_port(uport);
2698
2699 /*
2700 * Indicate that there isn't a port here anymore.
2701 */
2702 uport->type = PORT_UNKNOWN;
2703
2704 state->uart_port = NULL;
2705out:
2706 mutex_unlock(&port_mutex);
2707
2708 return ret;
2709}
2710
2711/*
2712 * Are the two ports equivalent?
2713 */
2714int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2715{
2716 if (port1->iotype != port2->iotype)
2717 return 0;
2718
2719 switch (port1->iotype) {
2720 case UPIO_PORT:
2721 return (port1->iobase == port2->iobase);
2722 case UPIO_HUB6:
2723 return (port1->iobase == port2->iobase) &&
2724 (port1->hub6 == port2->hub6);
2725 case UPIO_MEM:
2726 case UPIO_MEM32:
2727 case UPIO_AU:
2728 case UPIO_TSI:
2729 return (port1->mapbase == port2->mapbase);
2730 }
2731 return 0;
2732}
2733EXPORT_SYMBOL(uart_match_port);
2734
2735/**
2736 * uart_handle_dcd_change - handle a change of carrier detect state
2737 * @uport: uart_port structure for the open port
2738 * @status: new carrier detect status, nonzero if active
2739 */
2740void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2741{
2742 struct tty_port *port = &uport->state->port;
2743 struct tty_struct *tty = port->tty;
2744 struct tty_ldisc *ld = tty ? tty_ldisc_ref(tty) : NULL;
2745
2746 if (ld) {
2747 if (ld->ops->dcd_change)
2748 ld->ops->dcd_change(tty, status);
2749 tty_ldisc_deref(ld);
2750 }
2751
2752 uport->icount.dcd++;
2753
2754 if (port->flags & ASYNC_CHECK_CD) {
2755 if (status)
2756 wake_up_interruptible(&port->open_wait);
2757 else if (tty)
2758 tty_hangup(tty);
2759 }
2760}
2761EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2762
2763/**
2764 * uart_handle_cts_change - handle a change of clear-to-send state
2765 * @uport: uart_port structure for the open port
2766 * @status: new clear to send status, nonzero if active
2767 */
2768void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2769{
2770 struct tty_port *port = &uport->state->port;
2771 struct tty_struct *tty = port->tty;
2772
2773 uport->icount.cts++;
2774
2775 if (tty_port_cts_enabled(port)) {
2776 if (tty->hw_stopped) {
2777 if (status) {
2778 tty->hw_stopped = 0;
2779 uport->ops->start_tx(uport);
2780 uart_write_wakeup(uport);
2781 }
2782 } else {
2783 if (!status) {
2784 tty->hw_stopped = 1;
2785 uport->ops->stop_tx(uport);
2786 }
2787 }
2788 }
2789}
2790EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2791
2792/**
2793 * uart_insert_char - push a char to the uart layer
2794 *
2795 * User is responsible to call tty_flip_buffer_push when they are done with
2796 * insertion.
2797 *
2798 * @port: corresponding port
2799 * @status: state of the serial port RX buffer (LSR for 8250)
2800 * @overrun: mask of overrun bits in @status
2801 * @ch: character to push
2802 * @flag: flag for the character (see TTY_NORMAL and friends)
2803 */
2804void uart_insert_char(struct uart_port *port, unsigned int status,
2805 unsigned int overrun, unsigned int ch, unsigned int flag)
2806{
2807 struct tty_port *tport = &port->state->port;
2808
2809 if ((status & port->ignore_status_mask & ~overrun) == 0)
2810 if (tty_insert_flip_char(tport, ch, flag) == 0)
2811 ++port->icount.buf_overrun;
2812
2813 /*
2814 * Overrun is special. Since it's reported immediately,
2815 * it doesn't affect the current character.
2816 */
2817 if (status & ~port->ignore_status_mask & overrun)
2818 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2819 ++port->icount.buf_overrun;
2820}
2821EXPORT_SYMBOL_GPL(uart_insert_char);
2822
2823EXPORT_SYMBOL(uart_write_wakeup);
2824EXPORT_SYMBOL(uart_register_driver);
2825EXPORT_SYMBOL(uart_unregister_driver);
2826EXPORT_SYMBOL(uart_suspend_port);
2827EXPORT_SYMBOL(uart_resume_port);
2828EXPORT_SYMBOL(uart_add_one_port);
2829EXPORT_SYMBOL(uart_remove_one_port);
2830
2831MODULE_DESCRIPTION("Serial driver core");
2832MODULE_LICENSE("GPL");