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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/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 <linux/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
67static inline struct uart_port *uart_port_ref(struct uart_state *state)
68{
69 if (atomic_add_unless(&state->refcount, 1, 0))
70 return state->uart_port;
71 return NULL;
72}
73
74static inline void uart_port_deref(struct uart_port *uport)
75{
76 if (atomic_dec_and_test(&uport->state->refcount))
77 wake_up(&uport->state->remove_wait);
78}
79
80#define uart_port_lock(state, flags) \
81 ({ \
82 struct uart_port *__uport = uart_port_ref(state); \
83 if (__uport) \
84 spin_lock_irqsave(&__uport->lock, flags); \
85 __uport; \
86 })
87
88#define uart_port_unlock(uport, flags) \
89 ({ \
90 struct uart_port *__uport = uport; \
91 if (__uport) { \
92 spin_unlock_irqrestore(&__uport->lock, flags); \
93 uart_port_deref(__uport); \
94 } \
95 })
96
97static inline struct uart_port *uart_port_check(struct uart_state *state)
98{
99 lockdep_assert_held(&state->port.mutex);
100 return state->uart_port;
101}
102
103/*
104 * This routine is used by the interrupt handler to schedule processing in
105 * the software interrupt portion of the driver.
106 */
107void uart_write_wakeup(struct uart_port *port)
108{
109 struct uart_state *state = port->state;
110 /*
111 * This means you called this function _after_ the port was
112 * closed. No cookie for you.
113 */
114 BUG_ON(!state);
115 tty_port_tty_wakeup(&state->port);
116}
117
118static void uart_stop(struct tty_struct *tty)
119{
120 struct uart_state *state = tty->driver_data;
121 struct uart_port *port;
122 unsigned long flags;
123
124 port = uart_port_lock(state, flags);
125 if (port)
126 port->ops->stop_tx(port);
127 uart_port_unlock(port, flags);
128}
129
130static void __uart_start(struct tty_struct *tty)
131{
132 struct uart_state *state = tty->driver_data;
133 struct uart_port *port = state->uart_port;
134
135 if (port && !uart_tx_stopped(port))
136 port->ops->start_tx(port);
137}
138
139static void uart_start(struct tty_struct *tty)
140{
141 struct uart_state *state = tty->driver_data;
142 struct uart_port *port;
143 unsigned long flags;
144
145 port = uart_port_lock(state, flags);
146 __uart_start(tty);
147 uart_port_unlock(port, flags);
148}
149
150static void
151uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
152{
153 unsigned long flags;
154 unsigned int old;
155
156 spin_lock_irqsave(&port->lock, flags);
157 old = port->mctrl;
158 port->mctrl = (old & ~clear) | set;
159 if (old != port->mctrl)
160 port->ops->set_mctrl(port, port->mctrl);
161 spin_unlock_irqrestore(&port->lock, flags);
162}
163
164#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
165#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
166
167/*
168 * Startup the port. This will be called once per open. All calls
169 * will be serialised by the per-port mutex.
170 */
171static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
172 int init_hw)
173{
174 struct uart_port *uport = uart_port_check(state);
175 unsigned long page;
176 int retval = 0;
177
178 if (uport->type == PORT_UNKNOWN)
179 return 1;
180
181 /*
182 * Make sure the device is in D0 state.
183 */
184 uart_change_pm(state, UART_PM_STATE_ON);
185
186 /*
187 * Initialise and allocate the transmit and temporary
188 * buffer.
189 */
190 if (!state->xmit.buf) {
191 /* This is protected by the per port mutex */
192 page = get_zeroed_page(GFP_KERNEL);
193 if (!page)
194 return -ENOMEM;
195
196 state->xmit.buf = (unsigned char *) page;
197 uart_circ_clear(&state->xmit);
198 }
199
200 retval = uport->ops->startup(uport);
201 if (retval == 0) {
202 if (uart_console(uport) && uport->cons->cflag) {
203 tty->termios.c_cflag = uport->cons->cflag;
204 uport->cons->cflag = 0;
205 }
206 /*
207 * Initialise the hardware port settings.
208 */
209 uart_change_speed(tty, state, NULL);
210
211 /*
212 * Setup the RTS and DTR signals once the
213 * port is open and ready to respond.
214 */
215 if (init_hw && C_BAUD(tty))
216 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
217 }
218
219 /*
220 * This is to allow setserial on this port. People may want to set
221 * port/irq/type and then reconfigure the port properly if it failed
222 * now.
223 */
224 if (retval && capable(CAP_SYS_ADMIN))
225 return 1;
226
227 return retval;
228}
229
230static int uart_startup(struct tty_struct *tty, struct uart_state *state,
231 int init_hw)
232{
233 struct tty_port *port = &state->port;
234 int retval;
235
236 if (tty_port_initialized(port))
237 return 0;
238
239 retval = uart_port_startup(tty, state, init_hw);
240 if (retval)
241 set_bit(TTY_IO_ERROR, &tty->flags);
242
243 return retval;
244}
245
246/*
247 * This routine will shutdown a serial port; interrupts are disabled, and
248 * DTR is dropped if the hangup on close termio flag is on. Calls to
249 * uart_shutdown are serialised by the per-port semaphore.
250 *
251 * uport == NULL if uart_port has already been removed
252 */
253static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
254{
255 struct uart_port *uport = uart_port_check(state);
256 struct tty_port *port = &state->port;
257
258 /*
259 * Set the TTY IO error marker
260 */
261 if (tty)
262 set_bit(TTY_IO_ERROR, &tty->flags);
263
264 if (tty_port_initialized(port)) {
265 tty_port_set_initialized(port, 0);
266
267 /*
268 * Turn off DTR and RTS early.
269 */
270 if (uport && uart_console(uport) && tty)
271 uport->cons->cflag = tty->termios.c_cflag;
272
273 if (!tty || C_HUPCL(tty))
274 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
275
276 uart_port_shutdown(port);
277 }
278
279 /*
280 * It's possible for shutdown to be called after suspend if we get
281 * a DCD drop (hangup) at just the right time. Clear suspended bit so
282 * we don't try to resume a port that has been shutdown.
283 */
284 tty_port_set_suspended(port, 0);
285
286 /*
287 * Free the transmit buffer page.
288 */
289 if (state->xmit.buf) {
290 free_page((unsigned long)state->xmit.buf);
291 state->xmit.buf = NULL;
292 }
293}
294
295/**
296 * uart_update_timeout - update per-port FIFO timeout.
297 * @port: uart_port structure describing the port
298 * @cflag: termios cflag value
299 * @baud: speed of the port
300 *
301 * Set the port FIFO timeout value. The @cflag value should
302 * reflect the actual hardware settings.
303 */
304void
305uart_update_timeout(struct uart_port *port, unsigned int cflag,
306 unsigned int baud)
307{
308 unsigned int bits;
309
310 /* byte size and parity */
311 switch (cflag & CSIZE) {
312 case CS5:
313 bits = 7;
314 break;
315 case CS6:
316 bits = 8;
317 break;
318 case CS7:
319 bits = 9;
320 break;
321 default:
322 bits = 10;
323 break; /* CS8 */
324 }
325
326 if (cflag & CSTOPB)
327 bits++;
328 if (cflag & PARENB)
329 bits++;
330
331 /*
332 * The total number of bits to be transmitted in the fifo.
333 */
334 bits = bits * port->fifosize;
335
336 /*
337 * Figure the timeout to send the above number of bits.
338 * Add .02 seconds of slop
339 */
340 port->timeout = (HZ * bits) / baud + HZ/50;
341}
342
343EXPORT_SYMBOL(uart_update_timeout);
344
345/**
346 * uart_get_baud_rate - return baud rate for a particular port
347 * @port: uart_port structure describing the port in question.
348 * @termios: desired termios settings.
349 * @old: old termios (or NULL)
350 * @min: minimum acceptable baud rate
351 * @max: maximum acceptable baud rate
352 *
353 * Decode the termios structure into a numeric baud rate,
354 * taking account of the magic 38400 baud rate (with spd_*
355 * flags), and mapping the %B0 rate to 9600 baud.
356 *
357 * If the new baud rate is invalid, try the old termios setting.
358 * If it's still invalid, we try 9600 baud.
359 *
360 * Update the @termios structure to reflect the baud rate
361 * we're actually going to be using. Don't do this for the case
362 * where B0 is requested ("hang up").
363 */
364unsigned int
365uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
366 struct ktermios *old, unsigned int min, unsigned int max)
367{
368 unsigned int try;
369 unsigned int baud;
370 unsigned int altbaud;
371 int hung_up = 0;
372 upf_t flags = port->flags & UPF_SPD_MASK;
373
374 switch (flags) {
375 case UPF_SPD_HI:
376 altbaud = 57600;
377 break;
378 case UPF_SPD_VHI:
379 altbaud = 115200;
380 break;
381 case UPF_SPD_SHI:
382 altbaud = 230400;
383 break;
384 case UPF_SPD_WARP:
385 altbaud = 460800;
386 break;
387 default:
388 altbaud = 38400;
389 break;
390 }
391
392 for (try = 0; try < 2; try++) {
393 baud = tty_termios_baud_rate(termios);
394
395 /*
396 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
397 * Die! Die! Die!
398 */
399 if (try == 0 && baud == 38400)
400 baud = altbaud;
401
402 /*
403 * Special case: B0 rate.
404 */
405 if (baud == 0) {
406 hung_up = 1;
407 baud = 9600;
408 }
409
410 if (baud >= min && baud <= max)
411 return baud;
412
413 /*
414 * Oops, the quotient was zero. Try again with
415 * the old baud rate if possible.
416 */
417 termios->c_cflag &= ~CBAUD;
418 if (old) {
419 baud = tty_termios_baud_rate(old);
420 if (!hung_up)
421 tty_termios_encode_baud_rate(termios,
422 baud, baud);
423 old = NULL;
424 continue;
425 }
426
427 /*
428 * As a last resort, if the range cannot be met then clip to
429 * the nearest chip supported rate.
430 */
431 if (!hung_up) {
432 if (baud <= min)
433 tty_termios_encode_baud_rate(termios,
434 min + 1, min + 1);
435 else
436 tty_termios_encode_baud_rate(termios,
437 max - 1, max - 1);
438 }
439 }
440 /* Should never happen */
441 WARN_ON(1);
442 return 0;
443}
444
445EXPORT_SYMBOL(uart_get_baud_rate);
446
447/**
448 * uart_get_divisor - return uart clock divisor
449 * @port: uart_port structure describing the port.
450 * @baud: desired baud rate
451 *
452 * Calculate the uart clock divisor for the port.
453 */
454unsigned int
455uart_get_divisor(struct uart_port *port, unsigned int baud)
456{
457 unsigned int quot;
458
459 /*
460 * Old custom speed handling.
461 */
462 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
463 quot = port->custom_divisor;
464 else
465 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
466
467 return quot;
468}
469
470EXPORT_SYMBOL(uart_get_divisor);
471
472/* Caller holds port mutex */
473static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
474 struct ktermios *old_termios)
475{
476 struct uart_port *uport = uart_port_check(state);
477 struct ktermios *termios;
478 int hw_stopped;
479
480 /*
481 * If we have no tty, termios, or the port does not exist,
482 * then we can't set the parameters for this port.
483 */
484 if (!tty || uport->type == PORT_UNKNOWN)
485 return;
486
487 termios = &tty->termios;
488 uport->ops->set_termios(uport, termios, old_termios);
489
490 /*
491 * Set modem status enables based on termios cflag
492 */
493 spin_lock_irq(&uport->lock);
494 if (termios->c_cflag & CRTSCTS)
495 uport->status |= UPSTAT_CTS_ENABLE;
496 else
497 uport->status &= ~UPSTAT_CTS_ENABLE;
498
499 if (termios->c_cflag & CLOCAL)
500 uport->status &= ~UPSTAT_DCD_ENABLE;
501 else
502 uport->status |= UPSTAT_DCD_ENABLE;
503
504 /* reset sw-assisted CTS flow control based on (possibly) new mode */
505 hw_stopped = uport->hw_stopped;
506 uport->hw_stopped = uart_softcts_mode(uport) &&
507 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
508 if (uport->hw_stopped) {
509 if (!hw_stopped)
510 uport->ops->stop_tx(uport);
511 } else {
512 if (hw_stopped)
513 __uart_start(tty);
514 }
515 spin_unlock_irq(&uport->lock);
516}
517
518static int uart_put_char(struct tty_struct *tty, unsigned char c)
519{
520 struct uart_state *state = tty->driver_data;
521 struct uart_port *port;
522 struct circ_buf *circ;
523 unsigned long flags;
524 int ret = 0;
525
526 circ = &state->xmit;
527 if (!circ->buf)
528 return 0;
529
530 port = uart_port_lock(state, flags);
531 if (port && uart_circ_chars_free(circ) != 0) {
532 circ->buf[circ->head] = c;
533 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
534 ret = 1;
535 }
536 uart_port_unlock(port, flags);
537 return ret;
538}
539
540static void uart_flush_chars(struct tty_struct *tty)
541{
542 uart_start(tty);
543}
544
545static int uart_write(struct tty_struct *tty,
546 const unsigned char *buf, int count)
547{
548 struct uart_state *state = tty->driver_data;
549 struct uart_port *port;
550 struct circ_buf *circ;
551 unsigned long flags;
552 int c, ret = 0;
553
554 /*
555 * This means you called this function _after_ the port was
556 * closed. No cookie for you.
557 */
558 if (!state) {
559 WARN_ON(1);
560 return -EL3HLT;
561 }
562
563 circ = &state->xmit;
564 if (!circ->buf)
565 return 0;
566
567 port = uart_port_lock(state, flags);
568 while (port) {
569 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
570 if (count < c)
571 c = count;
572 if (c <= 0)
573 break;
574 memcpy(circ->buf + circ->head, buf, c);
575 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
576 buf += c;
577 count -= c;
578 ret += c;
579 }
580
581 __uart_start(tty);
582 uart_port_unlock(port, flags);
583 return ret;
584}
585
586static int uart_write_room(struct tty_struct *tty)
587{
588 struct uart_state *state = tty->driver_data;
589 struct uart_port *port;
590 unsigned long flags;
591 int ret;
592
593 port = uart_port_lock(state, flags);
594 ret = uart_circ_chars_free(&state->xmit);
595 uart_port_unlock(port, flags);
596 return ret;
597}
598
599static int uart_chars_in_buffer(struct tty_struct *tty)
600{
601 struct uart_state *state = tty->driver_data;
602 struct uart_port *port;
603 unsigned long flags;
604 int ret;
605
606 port = uart_port_lock(state, flags);
607 ret = uart_circ_chars_pending(&state->xmit);
608 uart_port_unlock(port, flags);
609 return ret;
610}
611
612static void uart_flush_buffer(struct tty_struct *tty)
613{
614 struct uart_state *state = tty->driver_data;
615 struct uart_port *port;
616 unsigned long flags;
617
618 /*
619 * This means you called this function _after_ the port was
620 * closed. No cookie for you.
621 */
622 if (!state) {
623 WARN_ON(1);
624 return;
625 }
626
627 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
628
629 port = uart_port_lock(state, flags);
630 if (!port)
631 return;
632 uart_circ_clear(&state->xmit);
633 if (port->ops->flush_buffer)
634 port->ops->flush_buffer(port);
635 uart_port_unlock(port, flags);
636 tty_port_tty_wakeup(&state->port);
637}
638
639/*
640 * This function is used to send a high-priority XON/XOFF character to
641 * the device
642 */
643static void uart_send_xchar(struct tty_struct *tty, char ch)
644{
645 struct uart_state *state = tty->driver_data;
646 struct uart_port *port;
647 unsigned long flags;
648
649 port = uart_port_ref(state);
650 if (!port)
651 return;
652
653 if (port->ops->send_xchar)
654 port->ops->send_xchar(port, ch);
655 else {
656 spin_lock_irqsave(&port->lock, flags);
657 port->x_char = ch;
658 if (ch)
659 port->ops->start_tx(port);
660 spin_unlock_irqrestore(&port->lock, flags);
661 }
662 uart_port_deref(port);
663}
664
665static void uart_throttle(struct tty_struct *tty)
666{
667 struct uart_state *state = tty->driver_data;
668 struct uart_port *port;
669 upstat_t mask = 0;
670
671 port = uart_port_ref(state);
672 if (!port)
673 return;
674
675 if (I_IXOFF(tty))
676 mask |= UPSTAT_AUTOXOFF;
677 if (C_CRTSCTS(tty))
678 mask |= UPSTAT_AUTORTS;
679
680 if (port->status & mask) {
681 port->ops->throttle(port);
682 mask &= ~port->status;
683 }
684
685 if (mask & UPSTAT_AUTORTS)
686 uart_clear_mctrl(port, TIOCM_RTS);
687
688 if (mask & UPSTAT_AUTOXOFF)
689 uart_send_xchar(tty, STOP_CHAR(tty));
690
691 uart_port_deref(port);
692}
693
694static void uart_unthrottle(struct tty_struct *tty)
695{
696 struct uart_state *state = tty->driver_data;
697 struct uart_port *port;
698 upstat_t mask = 0;
699
700 port = uart_port_ref(state);
701 if (!port)
702 return;
703
704 if (I_IXOFF(tty))
705 mask |= UPSTAT_AUTOXOFF;
706 if (C_CRTSCTS(tty))
707 mask |= UPSTAT_AUTORTS;
708
709 if (port->status & mask) {
710 port->ops->unthrottle(port);
711 mask &= ~port->status;
712 }
713
714 if (mask & UPSTAT_AUTORTS)
715 uart_set_mctrl(port, TIOCM_RTS);
716
717 if (mask & UPSTAT_AUTOXOFF)
718 uart_send_xchar(tty, START_CHAR(tty));
719
720 uart_port_deref(port);
721}
722
723static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
724{
725 struct uart_state *state = container_of(port, struct uart_state, port);
726 struct uart_port *uport;
727 int ret = -ENODEV;
728
729 memset(retinfo, 0, sizeof(*retinfo));
730
731 /*
732 * Ensure the state we copy is consistent and no hardware changes
733 * occur as we go
734 */
735 mutex_lock(&port->mutex);
736 uport = uart_port_check(state);
737 if (!uport)
738 goto out;
739
740 retinfo->type = uport->type;
741 retinfo->line = uport->line;
742 retinfo->port = uport->iobase;
743 if (HIGH_BITS_OFFSET)
744 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
745 retinfo->irq = uport->irq;
746 retinfo->flags = uport->flags;
747 retinfo->xmit_fifo_size = uport->fifosize;
748 retinfo->baud_base = uport->uartclk / 16;
749 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
750 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
751 ASYNC_CLOSING_WAIT_NONE :
752 jiffies_to_msecs(port->closing_wait) / 10;
753 retinfo->custom_divisor = uport->custom_divisor;
754 retinfo->hub6 = uport->hub6;
755 retinfo->io_type = uport->iotype;
756 retinfo->iomem_reg_shift = uport->regshift;
757 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
758
759 ret = 0;
760out:
761 mutex_unlock(&port->mutex);
762 return ret;
763}
764
765static int uart_get_info_user(struct tty_port *port,
766 struct serial_struct __user *retinfo)
767{
768 struct serial_struct tmp;
769
770 if (uart_get_info(port, &tmp) < 0)
771 return -EIO;
772
773 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
774 return -EFAULT;
775 return 0;
776}
777
778static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
779 struct uart_state *state,
780 struct serial_struct *new_info)
781{
782 struct uart_port *uport = uart_port_check(state);
783 unsigned long new_port;
784 unsigned int change_irq, change_port, closing_wait;
785 unsigned int old_custom_divisor, close_delay;
786 upf_t old_flags, new_flags;
787 int retval = 0;
788
789 if (!uport)
790 return -EIO;
791
792 new_port = new_info->port;
793 if (HIGH_BITS_OFFSET)
794 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
795
796 new_info->irq = irq_canonicalize(new_info->irq);
797 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
798 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
799 ASYNC_CLOSING_WAIT_NONE :
800 msecs_to_jiffies(new_info->closing_wait * 10);
801
802
803 change_irq = !(uport->flags & UPF_FIXED_PORT)
804 && new_info->irq != uport->irq;
805
806 /*
807 * Since changing the 'type' of the port changes its resource
808 * allocations, we should treat type changes the same as
809 * IO port changes.
810 */
811 change_port = !(uport->flags & UPF_FIXED_PORT)
812 && (new_port != uport->iobase ||
813 (unsigned long)new_info->iomem_base != uport->mapbase ||
814 new_info->hub6 != uport->hub6 ||
815 new_info->io_type != uport->iotype ||
816 new_info->iomem_reg_shift != uport->regshift ||
817 new_info->type != uport->type);
818
819 old_flags = uport->flags;
820 new_flags = new_info->flags;
821 old_custom_divisor = uport->custom_divisor;
822
823 if (!capable(CAP_SYS_ADMIN)) {
824 retval = -EPERM;
825 if (change_irq || change_port ||
826 (new_info->baud_base != uport->uartclk / 16) ||
827 (close_delay != port->close_delay) ||
828 (closing_wait != port->closing_wait) ||
829 (new_info->xmit_fifo_size &&
830 new_info->xmit_fifo_size != uport->fifosize) ||
831 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
832 goto exit;
833 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
834 (new_flags & UPF_USR_MASK));
835 uport->custom_divisor = new_info->custom_divisor;
836 goto check_and_exit;
837 }
838
839 /*
840 * Ask the low level driver to verify the settings.
841 */
842 if (uport->ops->verify_port)
843 retval = uport->ops->verify_port(uport, new_info);
844
845 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
846 (new_info->baud_base < 9600))
847 retval = -EINVAL;
848
849 if (retval)
850 goto exit;
851
852 if (change_port || change_irq) {
853 retval = -EBUSY;
854
855 /*
856 * Make sure that we are the sole user of this port.
857 */
858 if (tty_port_users(port) > 1)
859 goto exit;
860
861 /*
862 * We need to shutdown the serial port at the old
863 * port/type/irq combination.
864 */
865 uart_shutdown(tty, state);
866 }
867
868 if (change_port) {
869 unsigned long old_iobase, old_mapbase;
870 unsigned int old_type, old_iotype, old_hub6, old_shift;
871
872 old_iobase = uport->iobase;
873 old_mapbase = uport->mapbase;
874 old_type = uport->type;
875 old_hub6 = uport->hub6;
876 old_iotype = uport->iotype;
877 old_shift = uport->regshift;
878
879 /*
880 * Free and release old regions
881 */
882 if (old_type != PORT_UNKNOWN && uport->ops->release_port)
883 uport->ops->release_port(uport);
884
885 uport->iobase = new_port;
886 uport->type = new_info->type;
887 uport->hub6 = new_info->hub6;
888 uport->iotype = new_info->io_type;
889 uport->regshift = new_info->iomem_reg_shift;
890 uport->mapbase = (unsigned long)new_info->iomem_base;
891
892 /*
893 * Claim and map the new regions
894 */
895 if (uport->type != PORT_UNKNOWN && uport->ops->request_port) {
896 retval = uport->ops->request_port(uport);
897 } else {
898 /* Always success - Jean II */
899 retval = 0;
900 }
901
902 /*
903 * If we fail to request resources for the
904 * new port, try to restore the old settings.
905 */
906 if (retval) {
907 uport->iobase = old_iobase;
908 uport->type = old_type;
909 uport->hub6 = old_hub6;
910 uport->iotype = old_iotype;
911 uport->regshift = old_shift;
912 uport->mapbase = old_mapbase;
913
914 if (old_type != PORT_UNKNOWN) {
915 retval = uport->ops->request_port(uport);
916 /*
917 * If we failed to restore the old settings,
918 * we fail like this.
919 */
920 if (retval)
921 uport->type = PORT_UNKNOWN;
922
923 /*
924 * We failed anyway.
925 */
926 retval = -EBUSY;
927 }
928
929 /* Added to return the correct error -Ram Gupta */
930 goto exit;
931 }
932 }
933
934 if (change_irq)
935 uport->irq = new_info->irq;
936 if (!(uport->flags & UPF_FIXED_PORT))
937 uport->uartclk = new_info->baud_base * 16;
938 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
939 (new_flags & UPF_CHANGE_MASK);
940 uport->custom_divisor = new_info->custom_divisor;
941 port->close_delay = close_delay;
942 port->closing_wait = closing_wait;
943 if (new_info->xmit_fifo_size)
944 uport->fifosize = new_info->xmit_fifo_size;
945 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
946
947 check_and_exit:
948 retval = 0;
949 if (uport->type == PORT_UNKNOWN)
950 goto exit;
951 if (tty_port_initialized(port)) {
952 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
953 old_custom_divisor != uport->custom_divisor) {
954 /*
955 * If they're setting up a custom divisor or speed,
956 * instead of clearing it, then bitch about it. No
957 * need to rate-limit; it's CAP_SYS_ADMIN only.
958 */
959 if (uport->flags & UPF_SPD_MASK) {
960 dev_notice(uport->dev,
961 "%s sets custom speed on %s. This is deprecated.\n",
962 current->comm,
963 tty_name(port->tty));
964 }
965 uart_change_speed(tty, state, NULL);
966 }
967 } else {
968 retval = uart_startup(tty, state, 1);
969 if (retval > 0)
970 retval = 0;
971 }
972 exit:
973 return retval;
974}
975
976static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
977 struct serial_struct __user *newinfo)
978{
979 struct serial_struct new_serial;
980 struct tty_port *port = &state->port;
981 int retval;
982
983 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
984 return -EFAULT;
985
986 /*
987 * This semaphore protects port->count. It is also
988 * very useful to prevent opens. Also, take the
989 * port configuration semaphore to make sure that a
990 * module insertion/removal doesn't change anything
991 * under us.
992 */
993 mutex_lock(&port->mutex);
994 retval = uart_set_info(tty, port, state, &new_serial);
995 mutex_unlock(&port->mutex);
996 return retval;
997}
998
999/**
1000 * uart_get_lsr_info - get line status register info
1001 * @tty: tty associated with the UART
1002 * @state: UART being queried
1003 * @value: returned modem value
1004 */
1005static int uart_get_lsr_info(struct tty_struct *tty,
1006 struct uart_state *state, unsigned int __user *value)
1007{
1008 struct uart_port *uport = uart_port_check(state);
1009 unsigned int result;
1010
1011 result = uport->ops->tx_empty(uport);
1012
1013 /*
1014 * If we're about to load something into the transmit
1015 * register, we'll pretend the transmitter isn't empty to
1016 * avoid a race condition (depending on when the transmit
1017 * interrupt happens).
1018 */
1019 if (uport->x_char ||
1020 ((uart_circ_chars_pending(&state->xmit) > 0) &&
1021 !uart_tx_stopped(uport)))
1022 result &= ~TIOCSER_TEMT;
1023
1024 return put_user(result, value);
1025}
1026
1027static int uart_tiocmget(struct tty_struct *tty)
1028{
1029 struct uart_state *state = tty->driver_data;
1030 struct tty_port *port = &state->port;
1031 struct uart_port *uport;
1032 int result = -EIO;
1033
1034 mutex_lock(&port->mutex);
1035 uport = uart_port_check(state);
1036 if (!uport)
1037 goto out;
1038
1039 if (!tty_io_error(tty)) {
1040 result = uport->mctrl;
1041 spin_lock_irq(&uport->lock);
1042 result |= uport->ops->get_mctrl(uport);
1043 spin_unlock_irq(&uport->lock);
1044 }
1045out:
1046 mutex_unlock(&port->mutex);
1047 return result;
1048}
1049
1050static int
1051uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
1052{
1053 struct uart_state *state = tty->driver_data;
1054 struct tty_port *port = &state->port;
1055 struct uart_port *uport;
1056 int ret = -EIO;
1057
1058 mutex_lock(&port->mutex);
1059 uport = uart_port_check(state);
1060 if (!uport)
1061 goto out;
1062
1063 if (!tty_io_error(tty)) {
1064 uart_update_mctrl(uport, set, clear);
1065 ret = 0;
1066 }
1067out:
1068 mutex_unlock(&port->mutex);
1069 return ret;
1070}
1071
1072static int uart_break_ctl(struct tty_struct *tty, int break_state)
1073{
1074 struct uart_state *state = tty->driver_data;
1075 struct tty_port *port = &state->port;
1076 struct uart_port *uport;
1077 int ret = -EIO;
1078
1079 mutex_lock(&port->mutex);
1080 uport = uart_port_check(state);
1081 if (!uport)
1082 goto out;
1083
1084 if (uport->type != PORT_UNKNOWN)
1085 uport->ops->break_ctl(uport, break_state);
1086 ret = 0;
1087out:
1088 mutex_unlock(&port->mutex);
1089 return ret;
1090}
1091
1092static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1093{
1094 struct tty_port *port = &state->port;
1095 struct uart_port *uport;
1096 int flags, ret;
1097
1098 if (!capable(CAP_SYS_ADMIN))
1099 return -EPERM;
1100
1101 /*
1102 * Take the per-port semaphore. This prevents count from
1103 * changing, and hence any extra opens of the port while
1104 * we're auto-configuring.
1105 */
1106 if (mutex_lock_interruptible(&port->mutex))
1107 return -ERESTARTSYS;
1108
1109 uport = uart_port_check(state);
1110 if (!uport) {
1111 ret = -EIO;
1112 goto out;
1113 }
1114
1115 ret = -EBUSY;
1116 if (tty_port_users(port) == 1) {
1117 uart_shutdown(tty, state);
1118
1119 /*
1120 * If we already have a port type configured,
1121 * we must release its resources.
1122 */
1123 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
1124 uport->ops->release_port(uport);
1125
1126 flags = UART_CONFIG_TYPE;
1127 if (uport->flags & UPF_AUTO_IRQ)
1128 flags |= UART_CONFIG_IRQ;
1129
1130 /*
1131 * This will claim the ports resources if
1132 * a port is found.
1133 */
1134 uport->ops->config_port(uport, flags);
1135
1136 ret = uart_startup(tty, state, 1);
1137 if (ret > 0)
1138 ret = 0;
1139 }
1140out:
1141 mutex_unlock(&port->mutex);
1142 return ret;
1143}
1144
1145static void uart_enable_ms(struct uart_port *uport)
1146{
1147 /*
1148 * Force modem status interrupts on
1149 */
1150 if (uport->ops->enable_ms)
1151 uport->ops->enable_ms(uport);
1152}
1153
1154/*
1155 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1156 * - mask passed in arg for lines of interest
1157 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1158 * Caller should use TIOCGICOUNT to see which one it was
1159 *
1160 * FIXME: This wants extracting into a common all driver implementation
1161 * of TIOCMWAIT using tty_port.
1162 */
1163static int uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1164{
1165 struct uart_port *uport;
1166 struct tty_port *port = &state->port;
1167 DECLARE_WAITQUEUE(wait, current);
1168 struct uart_icount cprev, cnow;
1169 int ret;
1170
1171 /*
1172 * note the counters on entry
1173 */
1174 uport = uart_port_ref(state);
1175 if (!uport)
1176 return -EIO;
1177 spin_lock_irq(&uport->lock);
1178 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1179 uart_enable_ms(uport);
1180 spin_unlock_irq(&uport->lock);
1181
1182 add_wait_queue(&port->delta_msr_wait, &wait);
1183 for (;;) {
1184 spin_lock_irq(&uport->lock);
1185 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1186 spin_unlock_irq(&uport->lock);
1187
1188 set_current_state(TASK_INTERRUPTIBLE);
1189
1190 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1191 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1192 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1193 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1194 ret = 0;
1195 break;
1196 }
1197
1198 schedule();
1199
1200 /* see if a signal did it */
1201 if (signal_pending(current)) {
1202 ret = -ERESTARTSYS;
1203 break;
1204 }
1205
1206 cprev = cnow;
1207 }
1208 __set_current_state(TASK_RUNNING);
1209 remove_wait_queue(&port->delta_msr_wait, &wait);
1210 uart_port_deref(uport);
1211
1212 return ret;
1213}
1214
1215/*
1216 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1217 * Return: write counters to the user passed counter struct
1218 * NB: both 1->0 and 0->1 transitions are counted except for
1219 * RI where only 0->1 is counted.
1220 */
1221static int uart_get_icount(struct tty_struct *tty,
1222 struct serial_icounter_struct *icount)
1223{
1224 struct uart_state *state = tty->driver_data;
1225 struct uart_icount cnow;
1226 struct uart_port *uport;
1227
1228 uport = uart_port_ref(state);
1229 if (!uport)
1230 return -EIO;
1231 spin_lock_irq(&uport->lock);
1232 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1233 spin_unlock_irq(&uport->lock);
1234 uart_port_deref(uport);
1235
1236 icount->cts = cnow.cts;
1237 icount->dsr = cnow.dsr;
1238 icount->rng = cnow.rng;
1239 icount->dcd = cnow.dcd;
1240 icount->rx = cnow.rx;
1241 icount->tx = cnow.tx;
1242 icount->frame = cnow.frame;
1243 icount->overrun = cnow.overrun;
1244 icount->parity = cnow.parity;
1245 icount->brk = cnow.brk;
1246 icount->buf_overrun = cnow.buf_overrun;
1247
1248 return 0;
1249}
1250
1251static int uart_get_rs485_config(struct uart_port *port,
1252 struct serial_rs485 __user *rs485)
1253{
1254 unsigned long flags;
1255 struct serial_rs485 aux;
1256
1257 spin_lock_irqsave(&port->lock, flags);
1258 aux = port->rs485;
1259 spin_unlock_irqrestore(&port->lock, flags);
1260
1261 if (copy_to_user(rs485, &aux, sizeof(aux)))
1262 return -EFAULT;
1263
1264 return 0;
1265}
1266
1267static int uart_set_rs485_config(struct uart_port *port,
1268 struct serial_rs485 __user *rs485_user)
1269{
1270 struct serial_rs485 rs485;
1271 int ret;
1272 unsigned long flags;
1273
1274 if (!port->rs485_config)
1275 return -ENOIOCTLCMD;
1276
1277 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1278 return -EFAULT;
1279
1280 spin_lock_irqsave(&port->lock, flags);
1281 ret = port->rs485_config(port, &rs485);
1282 spin_unlock_irqrestore(&port->lock, flags);
1283 if (ret)
1284 return ret;
1285
1286 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1287 return -EFAULT;
1288
1289 return 0;
1290}
1291
1292/*
1293 * Called via sys_ioctl. We can use spin_lock_irq() here.
1294 */
1295static int
1296uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
1297{
1298 struct uart_state *state = tty->driver_data;
1299 struct tty_port *port = &state->port;
1300 struct uart_port *uport;
1301 void __user *uarg = (void __user *)arg;
1302 int ret = -ENOIOCTLCMD;
1303
1304
1305 /*
1306 * These ioctls don't rely on the hardware to be present.
1307 */
1308 switch (cmd) {
1309 case TIOCGSERIAL:
1310 ret = uart_get_info_user(port, uarg);
1311 break;
1312
1313 case TIOCSSERIAL:
1314 down_write(&tty->termios_rwsem);
1315 ret = uart_set_info_user(tty, state, uarg);
1316 up_write(&tty->termios_rwsem);
1317 break;
1318
1319 case TIOCSERCONFIG:
1320 down_write(&tty->termios_rwsem);
1321 ret = uart_do_autoconfig(tty, state);
1322 up_write(&tty->termios_rwsem);
1323 break;
1324
1325 case TIOCSERGWILD: /* obsolete */
1326 case TIOCSERSWILD: /* obsolete */
1327 ret = 0;
1328 break;
1329 }
1330
1331 if (ret != -ENOIOCTLCMD)
1332 goto out;
1333
1334 if (tty_io_error(tty)) {
1335 ret = -EIO;
1336 goto out;
1337 }
1338
1339 /*
1340 * The following should only be used when hardware is present.
1341 */
1342 switch (cmd) {
1343 case TIOCMIWAIT:
1344 ret = uart_wait_modem_status(state, arg);
1345 break;
1346 }
1347
1348 if (ret != -ENOIOCTLCMD)
1349 goto out;
1350
1351 mutex_lock(&port->mutex);
1352 uport = uart_port_check(state);
1353
1354 if (!uport || tty_io_error(tty)) {
1355 ret = -EIO;
1356 goto out_up;
1357 }
1358
1359 /*
1360 * All these rely on hardware being present and need to be
1361 * protected against the tty being hung up.
1362 */
1363
1364 switch (cmd) {
1365 case TIOCSERGETLSR: /* Get line status register */
1366 ret = uart_get_lsr_info(tty, state, uarg);
1367 break;
1368
1369 case TIOCGRS485:
1370 ret = uart_get_rs485_config(uport, uarg);
1371 break;
1372
1373 case TIOCSRS485:
1374 ret = uart_set_rs485_config(uport, uarg);
1375 break;
1376 default:
1377 if (uport->ops->ioctl)
1378 ret = uport->ops->ioctl(uport, cmd, arg);
1379 break;
1380 }
1381out_up:
1382 mutex_unlock(&port->mutex);
1383out:
1384 return ret;
1385}
1386
1387static void uart_set_ldisc(struct tty_struct *tty)
1388{
1389 struct uart_state *state = tty->driver_data;
1390 struct uart_port *uport;
1391
1392 mutex_lock(&state->port.mutex);
1393 uport = uart_port_check(state);
1394 if (uport && uport->ops->set_ldisc)
1395 uport->ops->set_ldisc(uport, &tty->termios);
1396 mutex_unlock(&state->port.mutex);
1397}
1398
1399static void uart_set_termios(struct tty_struct *tty,
1400 struct ktermios *old_termios)
1401{
1402 struct uart_state *state = tty->driver_data;
1403 struct uart_port *uport;
1404 unsigned int cflag = tty->termios.c_cflag;
1405 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1406 bool sw_changed = false;
1407
1408 mutex_lock(&state->port.mutex);
1409 uport = uart_port_check(state);
1410 if (!uport)
1411 goto out;
1412
1413 /*
1414 * Drivers doing software flow control also need to know
1415 * about changes to these input settings.
1416 */
1417 if (uport->flags & UPF_SOFT_FLOW) {
1418 iflag_mask |= IXANY|IXON|IXOFF;
1419 sw_changed =
1420 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1421 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1422 }
1423
1424 /*
1425 * These are the bits that are used to setup various
1426 * flags in the low level driver. We can ignore the Bfoo
1427 * bits in c_cflag; c_[io]speed will always be set
1428 * appropriately by set_termios() in tty_ioctl.c
1429 */
1430 if ((cflag ^ old_termios->c_cflag) == 0 &&
1431 tty->termios.c_ospeed == old_termios->c_ospeed &&
1432 tty->termios.c_ispeed == old_termios->c_ispeed &&
1433 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1434 !sw_changed) {
1435 goto out;
1436 }
1437
1438 uart_change_speed(tty, state, old_termios);
1439 /* reload cflag from termios; port driver may have overriden flags */
1440 cflag = tty->termios.c_cflag;
1441
1442 /* Handle transition to B0 status */
1443 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1444 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1445 /* Handle transition away from B0 status */
1446 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1447 unsigned int mask = TIOCM_DTR;
1448 if (!(cflag & CRTSCTS) || !tty_throttled(tty))
1449 mask |= TIOCM_RTS;
1450 uart_set_mctrl(uport, mask);
1451 }
1452out:
1453 mutex_unlock(&state->port.mutex);
1454}
1455
1456/*
1457 * Calls to uart_close() are serialised via the tty_lock in
1458 * drivers/tty/tty_io.c:tty_release()
1459 * drivers/tty/tty_io.c:do_tty_hangup()
1460 */
1461static void uart_close(struct tty_struct *tty, struct file *filp)
1462{
1463 struct uart_state *state = tty->driver_data;
1464 struct tty_port *port;
1465
1466 if (!state) {
1467 struct uart_driver *drv = tty->driver->driver_state;
1468
1469 state = drv->state + tty->index;
1470 port = &state->port;
1471 spin_lock_irq(&port->lock);
1472 --port->count;
1473 spin_unlock_irq(&port->lock);
1474 return;
1475 }
1476
1477 port = &state->port;
1478 pr_debug("uart_close(%d) called\n", tty->index);
1479
1480 tty_port_close(tty->port, tty, filp);
1481}
1482
1483static void uart_tty_port_shutdown(struct tty_port *port)
1484{
1485 struct uart_state *state = container_of(port, struct uart_state, port);
1486 struct uart_port *uport = uart_port_check(state);
1487
1488 /*
1489 * At this point, we stop accepting input. To do this, we
1490 * disable the receive line status interrupts.
1491 */
1492 if (WARN(!uport, "detached port still initialized!\n"))
1493 return;
1494
1495 spin_lock_irq(&uport->lock);
1496 uport->ops->stop_rx(uport);
1497 spin_unlock_irq(&uport->lock);
1498
1499 uart_port_shutdown(port);
1500
1501 /*
1502 * It's possible for shutdown to be called after suspend if we get
1503 * a DCD drop (hangup) at just the right time. Clear suspended bit so
1504 * we don't try to resume a port that has been shutdown.
1505 */
1506 tty_port_set_suspended(port, 0);
1507
1508 uart_change_pm(state, UART_PM_STATE_OFF);
1509
1510}
1511
1512static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1513{
1514 struct uart_state *state = tty->driver_data;
1515 struct uart_port *port;
1516 unsigned long char_time, expire;
1517
1518 port = uart_port_ref(state);
1519 if (!port)
1520 return;
1521
1522 if (port->type == PORT_UNKNOWN || port->fifosize == 0) {
1523 uart_port_deref(port);
1524 return;
1525 }
1526
1527 /*
1528 * Set the check interval to be 1/5 of the estimated time to
1529 * send a single character, and make it at least 1. The check
1530 * interval should also be less than the timeout.
1531 *
1532 * Note: we have to use pretty tight timings here to satisfy
1533 * the NIST-PCTS.
1534 */
1535 char_time = (port->timeout - HZ/50) / port->fifosize;
1536 char_time = char_time / 5;
1537 if (char_time == 0)
1538 char_time = 1;
1539 if (timeout && timeout < char_time)
1540 char_time = timeout;
1541
1542 /*
1543 * If the transmitter hasn't cleared in twice the approximate
1544 * amount of time to send the entire FIFO, it probably won't
1545 * ever clear. This assumes the UART isn't doing flow
1546 * control, which is currently the case. Hence, if it ever
1547 * takes longer than port->timeout, this is probably due to a
1548 * UART bug of some kind. So, we clamp the timeout parameter at
1549 * 2*port->timeout.
1550 */
1551 if (timeout == 0 || timeout > 2 * port->timeout)
1552 timeout = 2 * port->timeout;
1553
1554 expire = jiffies + timeout;
1555
1556 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1557 port->line, jiffies, expire);
1558
1559 /*
1560 * Check whether the transmitter is empty every 'char_time'.
1561 * 'timeout' / 'expire' give us the maximum amount of time
1562 * we wait.
1563 */
1564 while (!port->ops->tx_empty(port)) {
1565 msleep_interruptible(jiffies_to_msecs(char_time));
1566 if (signal_pending(current))
1567 break;
1568 if (time_after(jiffies, expire))
1569 break;
1570 }
1571 uart_port_deref(port);
1572}
1573
1574/*
1575 * Calls to uart_hangup() are serialised by the tty_lock in
1576 * drivers/tty/tty_io.c:do_tty_hangup()
1577 * This runs from a workqueue and can sleep for a _short_ time only.
1578 */
1579static void uart_hangup(struct tty_struct *tty)
1580{
1581 struct uart_state *state = tty->driver_data;
1582 struct tty_port *port = &state->port;
1583 struct uart_port *uport;
1584 unsigned long flags;
1585
1586 pr_debug("uart_hangup(%d)\n", tty->index);
1587
1588 mutex_lock(&port->mutex);
1589 uport = uart_port_check(state);
1590 WARN(!uport, "hangup of detached port!\n");
1591
1592 if (tty_port_active(port)) {
1593 uart_flush_buffer(tty);
1594 uart_shutdown(tty, state);
1595 spin_lock_irqsave(&port->lock, flags);
1596 port->count = 0;
1597 spin_unlock_irqrestore(&port->lock, flags);
1598 tty_port_set_active(port, 0);
1599 tty_port_tty_set(port, NULL);
1600 if (uport && !uart_console(uport))
1601 uart_change_pm(state, UART_PM_STATE_OFF);
1602 wake_up_interruptible(&port->open_wait);
1603 wake_up_interruptible(&port->delta_msr_wait);
1604 }
1605 mutex_unlock(&port->mutex);
1606}
1607
1608/* uport == NULL if uart_port has already been removed */
1609static void uart_port_shutdown(struct tty_port *port)
1610{
1611 struct uart_state *state = container_of(port, struct uart_state, port);
1612 struct uart_port *uport = uart_port_check(state);
1613
1614 /*
1615 * clear delta_msr_wait queue to avoid mem leaks: we may free
1616 * the irq here so the queue might never be woken up. Note
1617 * that we won't end up waiting on delta_msr_wait again since
1618 * any outstanding file descriptors should be pointing at
1619 * hung_up_tty_fops now.
1620 */
1621 wake_up_interruptible(&port->delta_msr_wait);
1622
1623 /*
1624 * Free the IRQ and disable the port.
1625 */
1626 if (uport)
1627 uport->ops->shutdown(uport);
1628
1629 /*
1630 * Ensure that the IRQ handler isn't running on another CPU.
1631 */
1632 if (uport)
1633 synchronize_irq(uport->irq);
1634}
1635
1636static int uart_carrier_raised(struct tty_port *port)
1637{
1638 struct uart_state *state = container_of(port, struct uart_state, port);
1639 struct uart_port *uport;
1640 int mctrl;
1641
1642 uport = uart_port_ref(state);
1643 /*
1644 * Should never observe uport == NULL since checks for hangup should
1645 * abort the tty_port_block_til_ready() loop before checking for carrier
1646 * raised -- but report carrier raised if it does anyway so open will
1647 * continue and not sleep
1648 */
1649 if (WARN_ON(!uport))
1650 return 1;
1651 spin_lock_irq(&uport->lock);
1652 uart_enable_ms(uport);
1653 mctrl = uport->ops->get_mctrl(uport);
1654 spin_unlock_irq(&uport->lock);
1655 uart_port_deref(uport);
1656 if (mctrl & TIOCM_CAR)
1657 return 1;
1658 return 0;
1659}
1660
1661static void uart_dtr_rts(struct tty_port *port, int onoff)
1662{
1663 struct uart_state *state = container_of(port, struct uart_state, port);
1664 struct uart_port *uport;
1665
1666 uport = uart_port_ref(state);
1667 if (!uport)
1668 return;
1669
1670 if (onoff)
1671 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1672 else
1673 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1674
1675 uart_port_deref(uport);
1676}
1677
1678/*
1679 * Calls to uart_open are serialised by the tty_lock in
1680 * drivers/tty/tty_io.c:tty_open()
1681 * Note that if this fails, then uart_close() _will_ be called.
1682 *
1683 * In time, we want to scrap the "opening nonpresent ports"
1684 * behaviour and implement an alternative way for setserial
1685 * to set base addresses/ports/types. This will allow us to
1686 * get rid of a certain amount of extra tests.
1687 */
1688static int uart_open(struct tty_struct *tty, struct file *filp)
1689{
1690 struct uart_driver *drv = tty->driver->driver_state;
1691 int retval, line = tty->index;
1692 struct uart_state *state = drv->state + line;
1693
1694 tty->driver_data = state;
1695
1696 retval = tty_port_open(&state->port, tty, filp);
1697 if (retval > 0)
1698 retval = 0;
1699
1700 return retval;
1701}
1702
1703static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1704{
1705 struct uart_state *state = container_of(port, struct uart_state, port);
1706 struct uart_port *uport;
1707
1708 uport = uart_port_check(state);
1709 if (!uport || uport->flags & UPF_DEAD)
1710 return -ENXIO;
1711
1712 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
1713
1714 /*
1715 * Start up the serial port.
1716 */
1717 return uart_startup(tty, state, 0);
1718}
1719
1720static const char *uart_type(struct uart_port *port)
1721{
1722 const char *str = NULL;
1723
1724 if (port->ops->type)
1725 str = port->ops->type(port);
1726
1727 if (!str)
1728 str = "unknown";
1729
1730 return str;
1731}
1732
1733#ifdef CONFIG_PROC_FS
1734
1735static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1736{
1737 struct uart_state *state = drv->state + i;
1738 struct tty_port *port = &state->port;
1739 enum uart_pm_state pm_state;
1740 struct uart_port *uport;
1741 char stat_buf[32];
1742 unsigned int status;
1743 int mmio;
1744
1745 mutex_lock(&port->mutex);
1746 uport = uart_port_check(state);
1747 if (!uport)
1748 goto out;
1749
1750 mmio = uport->iotype >= UPIO_MEM;
1751 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1752 uport->line, uart_type(uport),
1753 mmio ? "mmio:0x" : "port:",
1754 mmio ? (unsigned long long)uport->mapbase
1755 : (unsigned long long)uport->iobase,
1756 uport->irq);
1757
1758 if (uport->type == PORT_UNKNOWN) {
1759 seq_putc(m, '\n');
1760 goto out;
1761 }
1762
1763 if (capable(CAP_SYS_ADMIN)) {
1764 pm_state = state->pm_state;
1765 if (pm_state != UART_PM_STATE_ON)
1766 uart_change_pm(state, UART_PM_STATE_ON);
1767 spin_lock_irq(&uport->lock);
1768 status = uport->ops->get_mctrl(uport);
1769 spin_unlock_irq(&uport->lock);
1770 if (pm_state != UART_PM_STATE_ON)
1771 uart_change_pm(state, pm_state);
1772
1773 seq_printf(m, " tx:%d rx:%d",
1774 uport->icount.tx, uport->icount.rx);
1775 if (uport->icount.frame)
1776 seq_printf(m, " fe:%d", uport->icount.frame);
1777 if (uport->icount.parity)
1778 seq_printf(m, " pe:%d", uport->icount.parity);
1779 if (uport->icount.brk)
1780 seq_printf(m, " brk:%d", uport->icount.brk);
1781 if (uport->icount.overrun)
1782 seq_printf(m, " oe:%d", uport->icount.overrun);
1783
1784#define INFOBIT(bit, str) \
1785 if (uport->mctrl & (bit)) \
1786 strncat(stat_buf, (str), sizeof(stat_buf) - \
1787 strlen(stat_buf) - 2)
1788#define STATBIT(bit, str) \
1789 if (status & (bit)) \
1790 strncat(stat_buf, (str), sizeof(stat_buf) - \
1791 strlen(stat_buf) - 2)
1792
1793 stat_buf[0] = '\0';
1794 stat_buf[1] = '\0';
1795 INFOBIT(TIOCM_RTS, "|RTS");
1796 STATBIT(TIOCM_CTS, "|CTS");
1797 INFOBIT(TIOCM_DTR, "|DTR");
1798 STATBIT(TIOCM_DSR, "|DSR");
1799 STATBIT(TIOCM_CAR, "|CD");
1800 STATBIT(TIOCM_RNG, "|RI");
1801 if (stat_buf[0])
1802 stat_buf[0] = ' ';
1803
1804 seq_puts(m, stat_buf);
1805 }
1806 seq_putc(m, '\n');
1807#undef STATBIT
1808#undef INFOBIT
1809out:
1810 mutex_unlock(&port->mutex);
1811}
1812
1813static int uart_proc_show(struct seq_file *m, void *v)
1814{
1815 struct tty_driver *ttydrv = m->private;
1816 struct uart_driver *drv = ttydrv->driver_state;
1817 int i;
1818
1819 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
1820 for (i = 0; i < drv->nr; i++)
1821 uart_line_info(m, drv, i);
1822 return 0;
1823}
1824
1825static int uart_proc_open(struct inode *inode, struct file *file)
1826{
1827 return single_open(file, uart_proc_show, PDE_DATA(inode));
1828}
1829
1830static const struct file_operations uart_proc_fops = {
1831 .owner = THIS_MODULE,
1832 .open = uart_proc_open,
1833 .read = seq_read,
1834 .llseek = seq_lseek,
1835 .release = single_release,
1836};
1837#endif
1838
1839#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1840/**
1841 * uart_console_write - write a console message to a serial port
1842 * @port: the port to write the message
1843 * @s: array of characters
1844 * @count: number of characters in string to write
1845 * @putchar: function to write character to port
1846 */
1847void uart_console_write(struct uart_port *port, const char *s,
1848 unsigned int count,
1849 void (*putchar)(struct uart_port *, int))
1850{
1851 unsigned int i;
1852
1853 for (i = 0; i < count; i++, s++) {
1854 if (*s == '\n')
1855 putchar(port, '\r');
1856 putchar(port, *s);
1857 }
1858}
1859EXPORT_SYMBOL_GPL(uart_console_write);
1860
1861/*
1862 * Check whether an invalid uart number has been specified, and
1863 * if so, search for the first available port that does have
1864 * console support.
1865 */
1866struct uart_port * __init
1867uart_get_console(struct uart_port *ports, int nr, struct console *co)
1868{
1869 int idx = co->index;
1870
1871 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1872 ports[idx].membase == NULL))
1873 for (idx = 0; idx < nr; idx++)
1874 if (ports[idx].iobase != 0 ||
1875 ports[idx].membase != NULL)
1876 break;
1877
1878 co->index = idx;
1879
1880 return ports + idx;
1881}
1882
1883/**
1884 * uart_parse_earlycon - Parse earlycon options
1885 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1886 * @iotype: ptr for decoded iotype (out)
1887 * @addr: ptr for decoded mapbase/iobase (out)
1888 * @options: ptr for <options> field; NULL if not present (out)
1889 *
1890 * Decodes earlycon kernel command line parameters of the form
1891 * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1892 * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1893 *
1894 * The optional form
1895 * earlycon=<name>,0x<addr>,<options>
1896 * console=<name>,0x<addr>,<options>
1897 * is also accepted; the returned @iotype will be UPIO_MEM.
1898 *
1899 * Returns 0 on success or -EINVAL on failure
1900 */
1901int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
1902 char **options)
1903{
1904 if (strncmp(p, "mmio,", 5) == 0) {
1905 *iotype = UPIO_MEM;
1906 p += 5;
1907 } else if (strncmp(p, "mmio16,", 7) == 0) {
1908 *iotype = UPIO_MEM16;
1909 p += 7;
1910 } else if (strncmp(p, "mmio32,", 7) == 0) {
1911 *iotype = UPIO_MEM32;
1912 p += 7;
1913 } else if (strncmp(p, "mmio32be,", 9) == 0) {
1914 *iotype = UPIO_MEM32BE;
1915 p += 9;
1916 } else if (strncmp(p, "mmio32native,", 13) == 0) {
1917 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
1918 UPIO_MEM32BE : UPIO_MEM32;
1919 p += 13;
1920 } else if (strncmp(p, "io,", 3) == 0) {
1921 *iotype = UPIO_PORT;
1922 p += 3;
1923 } else if (strncmp(p, "0x", 2) == 0) {
1924 *iotype = UPIO_MEM;
1925 } else {
1926 return -EINVAL;
1927 }
1928
1929 /*
1930 * Before you replace it with kstrtoull(), think about options separator
1931 * (',') it will not tolerate
1932 */
1933 *addr = simple_strtoull(p, NULL, 0);
1934 p = strchr(p, ',');
1935 if (p)
1936 p++;
1937
1938 *options = p;
1939 return 0;
1940}
1941EXPORT_SYMBOL_GPL(uart_parse_earlycon);
1942
1943/**
1944 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1945 * @options: pointer to option string
1946 * @baud: pointer to an 'int' variable for the baud rate.
1947 * @parity: pointer to an 'int' variable for the parity.
1948 * @bits: pointer to an 'int' variable for the number of data bits.
1949 * @flow: pointer to an 'int' variable for the flow control character.
1950 *
1951 * uart_parse_options decodes a string containing the serial console
1952 * options. The format of the string is <baud><parity><bits><flow>,
1953 * eg: 115200n8r
1954 */
1955void
1956uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1957{
1958 char *s = options;
1959
1960 *baud = simple_strtoul(s, NULL, 10);
1961 while (*s >= '0' && *s <= '9')
1962 s++;
1963 if (*s)
1964 *parity = *s++;
1965 if (*s)
1966 *bits = *s++ - '0';
1967 if (*s)
1968 *flow = *s;
1969}
1970EXPORT_SYMBOL_GPL(uart_parse_options);
1971
1972/**
1973 * uart_set_options - setup the serial console parameters
1974 * @port: pointer to the serial ports uart_port structure
1975 * @co: console pointer
1976 * @baud: baud rate
1977 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1978 * @bits: number of data bits
1979 * @flow: flow control character - 'r' (rts)
1980 */
1981int
1982uart_set_options(struct uart_port *port, struct console *co,
1983 int baud, int parity, int bits, int flow)
1984{
1985 struct ktermios termios;
1986 static struct ktermios dummy;
1987
1988 /*
1989 * Ensure that the serial console lock is initialised
1990 * early.
1991 * If this port is a console, then the spinlock is already
1992 * initialised.
1993 */
1994 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1995 spin_lock_init(&port->lock);
1996 lockdep_set_class(&port->lock, &port_lock_key);
1997 }
1998
1999 memset(&termios, 0, sizeof(struct ktermios));
2000
2001 termios.c_cflag |= CREAD | HUPCL | CLOCAL;
2002 tty_termios_encode_baud_rate(&termios, baud, baud);
2003
2004 if (bits == 7)
2005 termios.c_cflag |= CS7;
2006 else
2007 termios.c_cflag |= CS8;
2008
2009 switch (parity) {
2010 case 'o': case 'O':
2011 termios.c_cflag |= PARODD;
2012 /*fall through*/
2013 case 'e': case 'E':
2014 termios.c_cflag |= PARENB;
2015 break;
2016 }
2017
2018 if (flow == 'r')
2019 termios.c_cflag |= CRTSCTS;
2020
2021 /*
2022 * some uarts on other side don't support no flow control.
2023 * So we set * DTR in host uart to make them happy
2024 */
2025 port->mctrl |= TIOCM_DTR;
2026
2027 port->ops->set_termios(port, &termios, &dummy);
2028 /*
2029 * Allow the setting of the UART parameters with a NULL console
2030 * too:
2031 */
2032 if (co)
2033 co->cflag = termios.c_cflag;
2034
2035 return 0;
2036}
2037EXPORT_SYMBOL_GPL(uart_set_options);
2038#endif /* CONFIG_SERIAL_CORE_CONSOLE */
2039
2040/**
2041 * uart_change_pm - set power state of the port
2042 *
2043 * @state: port descriptor
2044 * @pm_state: new state
2045 *
2046 * Locking: port->mutex has to be held
2047 */
2048static void uart_change_pm(struct uart_state *state,
2049 enum uart_pm_state pm_state)
2050{
2051 struct uart_port *port = uart_port_check(state);
2052
2053 if (state->pm_state != pm_state) {
2054 if (port && port->ops->pm)
2055 port->ops->pm(port, pm_state, state->pm_state);
2056 state->pm_state = pm_state;
2057 }
2058}
2059
2060struct uart_match {
2061 struct uart_port *port;
2062 struct uart_driver *driver;
2063};
2064
2065static int serial_match_port(struct device *dev, void *data)
2066{
2067 struct uart_match *match = data;
2068 struct tty_driver *tty_drv = match->driver->tty_driver;
2069 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
2070 match->port->line;
2071
2072 return dev->devt == devt; /* Actually, only one tty per port */
2073}
2074
2075int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
2076{
2077 struct uart_state *state = drv->state + uport->line;
2078 struct tty_port *port = &state->port;
2079 struct device *tty_dev;
2080 struct uart_match match = {uport, drv};
2081
2082 mutex_lock(&port->mutex);
2083
2084 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2085 if (device_may_wakeup(tty_dev)) {
2086 if (!enable_irq_wake(uport->irq))
2087 uport->irq_wake = 1;
2088 put_device(tty_dev);
2089 mutex_unlock(&port->mutex);
2090 return 0;
2091 }
2092 put_device(tty_dev);
2093
2094 /* Nothing to do if the console is not suspending */
2095 if (!console_suspend_enabled && uart_console(uport))
2096 goto unlock;
2097
2098 uport->suspended = 1;
2099
2100 if (tty_port_initialized(port)) {
2101 const struct uart_ops *ops = uport->ops;
2102 int tries;
2103
2104 tty_port_set_suspended(port, 1);
2105 tty_port_set_initialized(port, 0);
2106
2107 spin_lock_irq(&uport->lock);
2108 ops->stop_tx(uport);
2109 ops->set_mctrl(uport, 0);
2110 ops->stop_rx(uport);
2111 spin_unlock_irq(&uport->lock);
2112
2113 /*
2114 * Wait for the transmitter to empty.
2115 */
2116 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2117 msleep(10);
2118 if (!tries)
2119 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
2120 drv->dev_name,
2121 drv->tty_driver->name_base + uport->line);
2122
2123 ops->shutdown(uport);
2124 }
2125
2126 /*
2127 * Disable the console device before suspending.
2128 */
2129 if (uart_console(uport))
2130 console_stop(uport->cons);
2131
2132 uart_change_pm(state, UART_PM_STATE_OFF);
2133unlock:
2134 mutex_unlock(&port->mutex);
2135
2136 return 0;
2137}
2138
2139int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2140{
2141 struct uart_state *state = drv->state + uport->line;
2142 struct tty_port *port = &state->port;
2143 struct device *tty_dev;
2144 struct uart_match match = {uport, drv};
2145 struct ktermios termios;
2146
2147 mutex_lock(&port->mutex);
2148
2149 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2150 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2151 if (uport->irq_wake) {
2152 disable_irq_wake(uport->irq);
2153 uport->irq_wake = 0;
2154 }
2155 put_device(tty_dev);
2156 mutex_unlock(&port->mutex);
2157 return 0;
2158 }
2159 put_device(tty_dev);
2160 uport->suspended = 0;
2161
2162 /*
2163 * Re-enable the console device after suspending.
2164 */
2165 if (uart_console(uport)) {
2166 /*
2167 * First try to use the console cflag setting.
2168 */
2169 memset(&termios, 0, sizeof(struct ktermios));
2170 termios.c_cflag = uport->cons->cflag;
2171
2172 /*
2173 * If that's unset, use the tty termios setting.
2174 */
2175 if (port->tty && termios.c_cflag == 0)
2176 termios = port->tty->termios;
2177
2178 if (console_suspend_enabled)
2179 uart_change_pm(state, UART_PM_STATE_ON);
2180 uport->ops->set_termios(uport, &termios, NULL);
2181 if (console_suspend_enabled)
2182 console_start(uport->cons);
2183 }
2184
2185 if (tty_port_suspended(port)) {
2186 const struct uart_ops *ops = uport->ops;
2187 int ret;
2188
2189 uart_change_pm(state, UART_PM_STATE_ON);
2190 spin_lock_irq(&uport->lock);
2191 ops->set_mctrl(uport, 0);
2192 spin_unlock_irq(&uport->lock);
2193 if (console_suspend_enabled || !uart_console(uport)) {
2194 /* Protected by port mutex for now */
2195 struct tty_struct *tty = port->tty;
2196 ret = ops->startup(uport);
2197 if (ret == 0) {
2198 if (tty)
2199 uart_change_speed(tty, state, NULL);
2200 spin_lock_irq(&uport->lock);
2201 ops->set_mctrl(uport, uport->mctrl);
2202 ops->start_tx(uport);
2203 spin_unlock_irq(&uport->lock);
2204 tty_port_set_initialized(port, 1);
2205 } else {
2206 /*
2207 * Failed to resume - maybe hardware went away?
2208 * Clear the "initialized" flag so we won't try
2209 * to call the low level drivers shutdown method.
2210 */
2211 uart_shutdown(tty, state);
2212 }
2213 }
2214
2215 tty_port_set_suspended(port, 0);
2216 }
2217
2218 mutex_unlock(&port->mutex);
2219
2220 return 0;
2221}
2222
2223static inline void
2224uart_report_port(struct uart_driver *drv, struct uart_port *port)
2225{
2226 char address[64];
2227
2228 switch (port->iotype) {
2229 case UPIO_PORT:
2230 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2231 break;
2232 case UPIO_HUB6:
2233 snprintf(address, sizeof(address),
2234 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2235 break;
2236 case UPIO_MEM:
2237 case UPIO_MEM16:
2238 case UPIO_MEM32:
2239 case UPIO_MEM32BE:
2240 case UPIO_AU:
2241 case UPIO_TSI:
2242 snprintf(address, sizeof(address),
2243 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2244 break;
2245 default:
2246 strlcpy(address, "*unknown*", sizeof(address));
2247 break;
2248 }
2249
2250 printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2251 port->dev ? dev_name(port->dev) : "",
2252 port->dev ? ": " : "",
2253 drv->dev_name,
2254 drv->tty_driver->name_base + port->line,
2255 address, port->irq, port->uartclk / 16, uart_type(port));
2256}
2257
2258static void
2259uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2260 struct uart_port *port)
2261{
2262 unsigned int flags;
2263
2264 /*
2265 * If there isn't a port here, don't do anything further.
2266 */
2267 if (!port->iobase && !port->mapbase && !port->membase)
2268 return;
2269
2270 /*
2271 * Now do the auto configuration stuff. Note that config_port
2272 * is expected to claim the resources and map the port for us.
2273 */
2274 flags = 0;
2275 if (port->flags & UPF_AUTO_IRQ)
2276 flags |= UART_CONFIG_IRQ;
2277 if (port->flags & UPF_BOOT_AUTOCONF) {
2278 if (!(port->flags & UPF_FIXED_TYPE)) {
2279 port->type = PORT_UNKNOWN;
2280 flags |= UART_CONFIG_TYPE;
2281 }
2282 port->ops->config_port(port, flags);
2283 }
2284
2285 if (port->type != PORT_UNKNOWN) {
2286 unsigned long flags;
2287
2288 uart_report_port(drv, port);
2289
2290 /* Power up port for set_mctrl() */
2291 uart_change_pm(state, UART_PM_STATE_ON);
2292
2293 /*
2294 * Ensure that the modem control lines are de-activated.
2295 * keep the DTR setting that is set in uart_set_options()
2296 * We probably don't need a spinlock around this, but
2297 */
2298 spin_lock_irqsave(&port->lock, flags);
2299 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2300 spin_unlock_irqrestore(&port->lock, flags);
2301
2302 /*
2303 * If this driver supports console, and it hasn't been
2304 * successfully registered yet, try to re-register it.
2305 * It may be that the port was not available.
2306 */
2307 if (port->cons && !(port->cons->flags & CON_ENABLED))
2308 register_console(port->cons);
2309
2310 /*
2311 * Power down all ports by default, except the
2312 * console if we have one.
2313 */
2314 if (!uart_console(port))
2315 uart_change_pm(state, UART_PM_STATE_OFF);
2316 }
2317}
2318
2319#ifdef CONFIG_CONSOLE_POLL
2320
2321static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2322{
2323 struct uart_driver *drv = driver->driver_state;
2324 struct uart_state *state = drv->state + line;
2325 struct tty_port *tport;
2326 struct uart_port *port;
2327 int baud = 9600;
2328 int bits = 8;
2329 int parity = 'n';
2330 int flow = 'n';
2331 int ret = 0;
2332
2333 if (!state)
2334 return -1;
2335
2336 tport = &state->port;
2337 mutex_lock(&tport->mutex);
2338
2339 port = uart_port_check(state);
2340 if (!port || !(port->ops->poll_get_char && port->ops->poll_put_char)) {
2341 ret = -1;
2342 goto out;
2343 }
2344
2345 if (port->ops->poll_init) {
2346 /*
2347 * We don't set initialized as we only initialized the hw,
2348 * e.g. state->xmit is still uninitialized.
2349 */
2350 if (!tty_port_initialized(tport))
2351 ret = port->ops->poll_init(port);
2352 }
2353
2354 if (!ret && options) {
2355 uart_parse_options(options, &baud, &parity, &bits, &flow);
2356 ret = uart_set_options(port, NULL, baud, parity, bits, flow);
2357 }
2358out:
2359 mutex_unlock(&tport->mutex);
2360 return ret;
2361}
2362
2363static int uart_poll_get_char(struct tty_driver *driver, int line)
2364{
2365 struct uart_driver *drv = driver->driver_state;
2366 struct uart_state *state = drv->state + line;
2367 struct uart_port *port;
2368 int ret = -1;
2369
2370 if (state) {
2371 port = uart_port_ref(state);
2372 if (port) {
2373 ret = port->ops->poll_get_char(port);
2374 uart_port_deref(port);
2375 }
2376 }
2377 return ret;
2378}
2379
2380static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2381{
2382 struct uart_driver *drv = driver->driver_state;
2383 struct uart_state *state = drv->state + line;
2384 struct uart_port *port;
2385
2386 if (!state)
2387 return;
2388
2389 port = uart_port_ref(state);
2390 if (!port)
2391 return;
2392
2393 if (ch == '\n')
2394 port->ops->poll_put_char(port, '\r');
2395 port->ops->poll_put_char(port, ch);
2396 uart_port_deref(port);
2397}
2398#endif
2399
2400static const struct tty_operations uart_ops = {
2401 .open = uart_open,
2402 .close = uart_close,
2403 .write = uart_write,
2404 .put_char = uart_put_char,
2405 .flush_chars = uart_flush_chars,
2406 .write_room = uart_write_room,
2407 .chars_in_buffer= uart_chars_in_buffer,
2408 .flush_buffer = uart_flush_buffer,
2409 .ioctl = uart_ioctl,
2410 .throttle = uart_throttle,
2411 .unthrottle = uart_unthrottle,
2412 .send_xchar = uart_send_xchar,
2413 .set_termios = uart_set_termios,
2414 .set_ldisc = uart_set_ldisc,
2415 .stop = uart_stop,
2416 .start = uart_start,
2417 .hangup = uart_hangup,
2418 .break_ctl = uart_break_ctl,
2419 .wait_until_sent= uart_wait_until_sent,
2420#ifdef CONFIG_PROC_FS
2421 .proc_fops = &uart_proc_fops,
2422#endif
2423 .tiocmget = uart_tiocmget,
2424 .tiocmset = uart_tiocmset,
2425 .get_icount = uart_get_icount,
2426#ifdef CONFIG_CONSOLE_POLL
2427 .poll_init = uart_poll_init,
2428 .poll_get_char = uart_poll_get_char,
2429 .poll_put_char = uart_poll_put_char,
2430#endif
2431};
2432
2433static const struct tty_port_operations uart_port_ops = {
2434 .carrier_raised = uart_carrier_raised,
2435 .dtr_rts = uart_dtr_rts,
2436 .activate = uart_port_activate,
2437 .shutdown = uart_tty_port_shutdown,
2438};
2439
2440/**
2441 * uart_register_driver - register a driver with the uart core layer
2442 * @drv: low level driver structure
2443 *
2444 * Register a uart driver with the core driver. We in turn register
2445 * with the tty layer, and initialise the core driver per-port state.
2446 *
2447 * We have a proc file in /proc/tty/driver which is named after the
2448 * normal driver.
2449 *
2450 * drv->port should be NULL, and the per-port structures should be
2451 * registered using uart_add_one_port after this call has succeeded.
2452 */
2453int uart_register_driver(struct uart_driver *drv)
2454{
2455 struct tty_driver *normal;
2456 int i, retval;
2457
2458 BUG_ON(drv->state);
2459
2460 /*
2461 * Maybe we should be using a slab cache for this, especially if
2462 * we have a large number of ports to handle.
2463 */
2464 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2465 if (!drv->state)
2466 goto out;
2467
2468 normal = alloc_tty_driver(drv->nr);
2469 if (!normal)
2470 goto out_kfree;
2471
2472 drv->tty_driver = normal;
2473
2474 normal->driver_name = drv->driver_name;
2475 normal->name = drv->dev_name;
2476 normal->major = drv->major;
2477 normal->minor_start = drv->minor;
2478 normal->type = TTY_DRIVER_TYPE_SERIAL;
2479 normal->subtype = SERIAL_TYPE_NORMAL;
2480 normal->init_termios = tty_std_termios;
2481 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2482 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2483 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2484 normal->driver_state = drv;
2485 tty_set_operations(normal, &uart_ops);
2486
2487 /*
2488 * Initialise the UART state(s).
2489 */
2490 for (i = 0; i < drv->nr; i++) {
2491 struct uart_state *state = drv->state + i;
2492 struct tty_port *port = &state->port;
2493
2494 tty_port_init(port);
2495 port->ops = &uart_port_ops;
2496 }
2497
2498 retval = tty_register_driver(normal);
2499 if (retval >= 0)
2500 return retval;
2501
2502 for (i = 0; i < drv->nr; i++)
2503 tty_port_destroy(&drv->state[i].port);
2504 put_tty_driver(normal);
2505out_kfree:
2506 kfree(drv->state);
2507out:
2508 return -ENOMEM;
2509}
2510
2511/**
2512 * uart_unregister_driver - remove a driver from the uart core layer
2513 * @drv: low level driver structure
2514 *
2515 * Remove all references to a driver from the core driver. The low
2516 * level driver must have removed all its ports via the
2517 * uart_remove_one_port() if it registered them with uart_add_one_port().
2518 * (ie, drv->port == NULL)
2519 */
2520void uart_unregister_driver(struct uart_driver *drv)
2521{
2522 struct tty_driver *p = drv->tty_driver;
2523 unsigned int i;
2524
2525 tty_unregister_driver(p);
2526 put_tty_driver(p);
2527 for (i = 0; i < drv->nr; i++)
2528 tty_port_destroy(&drv->state[i].port);
2529 kfree(drv->state);
2530 drv->state = NULL;
2531 drv->tty_driver = NULL;
2532}
2533
2534struct tty_driver *uart_console_device(struct console *co, int *index)
2535{
2536 struct uart_driver *p = co->data;
2537 *index = co->index;
2538 return p->tty_driver;
2539}
2540
2541static ssize_t uart_get_attr_uartclk(struct device *dev,
2542 struct device_attribute *attr, char *buf)
2543{
2544 struct serial_struct tmp;
2545 struct tty_port *port = dev_get_drvdata(dev);
2546
2547 uart_get_info(port, &tmp);
2548 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2549}
2550
2551static ssize_t uart_get_attr_type(struct device *dev,
2552 struct device_attribute *attr, char *buf)
2553{
2554 struct serial_struct tmp;
2555 struct tty_port *port = dev_get_drvdata(dev);
2556
2557 uart_get_info(port, &tmp);
2558 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2559}
2560static ssize_t uart_get_attr_line(struct device *dev,
2561 struct device_attribute *attr, char *buf)
2562{
2563 struct serial_struct tmp;
2564 struct tty_port *port = dev_get_drvdata(dev);
2565
2566 uart_get_info(port, &tmp);
2567 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2568}
2569
2570static ssize_t uart_get_attr_port(struct device *dev,
2571 struct device_attribute *attr, char *buf)
2572{
2573 struct serial_struct tmp;
2574 struct tty_port *port = dev_get_drvdata(dev);
2575 unsigned long ioaddr;
2576
2577 uart_get_info(port, &tmp);
2578 ioaddr = tmp.port;
2579 if (HIGH_BITS_OFFSET)
2580 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2581 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2582}
2583
2584static ssize_t uart_get_attr_irq(struct device *dev,
2585 struct device_attribute *attr, char *buf)
2586{
2587 struct serial_struct tmp;
2588 struct tty_port *port = dev_get_drvdata(dev);
2589
2590 uart_get_info(port, &tmp);
2591 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2592}
2593
2594static ssize_t uart_get_attr_flags(struct device *dev,
2595 struct device_attribute *attr, char *buf)
2596{
2597 struct serial_struct tmp;
2598 struct tty_port *port = dev_get_drvdata(dev);
2599
2600 uart_get_info(port, &tmp);
2601 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2602}
2603
2604static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2605 struct device_attribute *attr, char *buf)
2606{
2607 struct serial_struct tmp;
2608 struct tty_port *port = dev_get_drvdata(dev);
2609
2610 uart_get_info(port, &tmp);
2611 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2612}
2613
2614
2615static ssize_t uart_get_attr_close_delay(struct device *dev,
2616 struct device_attribute *attr, char *buf)
2617{
2618 struct serial_struct tmp;
2619 struct tty_port *port = dev_get_drvdata(dev);
2620
2621 uart_get_info(port, &tmp);
2622 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2623}
2624
2625
2626static ssize_t uart_get_attr_closing_wait(struct device *dev,
2627 struct device_attribute *attr, char *buf)
2628{
2629 struct serial_struct tmp;
2630 struct tty_port *port = dev_get_drvdata(dev);
2631
2632 uart_get_info(port, &tmp);
2633 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2634}
2635
2636static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2637 struct device_attribute *attr, char *buf)
2638{
2639 struct serial_struct tmp;
2640 struct tty_port *port = dev_get_drvdata(dev);
2641
2642 uart_get_info(port, &tmp);
2643 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2644}
2645
2646static ssize_t uart_get_attr_io_type(struct device *dev,
2647 struct device_attribute *attr, char *buf)
2648{
2649 struct serial_struct tmp;
2650 struct tty_port *port = dev_get_drvdata(dev);
2651
2652 uart_get_info(port, &tmp);
2653 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2654}
2655
2656static ssize_t uart_get_attr_iomem_base(struct device *dev,
2657 struct device_attribute *attr, char *buf)
2658{
2659 struct serial_struct tmp;
2660 struct tty_port *port = dev_get_drvdata(dev);
2661
2662 uart_get_info(port, &tmp);
2663 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2664}
2665
2666static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2667 struct device_attribute *attr, char *buf)
2668{
2669 struct serial_struct tmp;
2670 struct tty_port *port = dev_get_drvdata(dev);
2671
2672 uart_get_info(port, &tmp);
2673 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2674}
2675
2676static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2677static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2678static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2679static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2680static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2681static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2682static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2683static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2684static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2685static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2686static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2687static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2688static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2689
2690static struct attribute *tty_dev_attrs[] = {
2691 &dev_attr_type.attr,
2692 &dev_attr_line.attr,
2693 &dev_attr_port.attr,
2694 &dev_attr_irq.attr,
2695 &dev_attr_flags.attr,
2696 &dev_attr_xmit_fifo_size.attr,
2697 &dev_attr_uartclk.attr,
2698 &dev_attr_close_delay.attr,
2699 &dev_attr_closing_wait.attr,
2700 &dev_attr_custom_divisor.attr,
2701 &dev_attr_io_type.attr,
2702 &dev_attr_iomem_base.attr,
2703 &dev_attr_iomem_reg_shift.attr,
2704 NULL,
2705 };
2706
2707static const struct attribute_group tty_dev_attr_group = {
2708 .attrs = tty_dev_attrs,
2709 };
2710
2711/**
2712 * uart_add_one_port - attach a driver-defined port structure
2713 * @drv: pointer to the uart low level driver structure for this port
2714 * @uport: uart port structure to use for this port.
2715 *
2716 * This allows the driver to register its own uart_port structure
2717 * with the core driver. The main purpose is to allow the low
2718 * level uart drivers to expand uart_port, rather than having yet
2719 * more levels of structures.
2720 */
2721int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2722{
2723 struct uart_state *state;
2724 struct tty_port *port;
2725 int ret = 0;
2726 struct device *tty_dev;
2727 int num_groups;
2728
2729 BUG_ON(in_interrupt());
2730
2731 if (uport->line >= drv->nr)
2732 return -EINVAL;
2733
2734 state = drv->state + uport->line;
2735 port = &state->port;
2736
2737 mutex_lock(&port_mutex);
2738 mutex_lock(&port->mutex);
2739 if (state->uart_port) {
2740 ret = -EINVAL;
2741 goto out;
2742 }
2743
2744 /* Link the port to the driver state table and vice versa */
2745 atomic_set(&state->refcount, 1);
2746 init_waitqueue_head(&state->remove_wait);
2747 state->uart_port = uport;
2748 uport->state = state;
2749
2750 state->pm_state = UART_PM_STATE_UNDEFINED;
2751 uport->cons = drv->cons;
2752 uport->minor = drv->tty_driver->minor_start + uport->line;
2753
2754 /*
2755 * If this port is a console, then the spinlock is already
2756 * initialised.
2757 */
2758 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2759 spin_lock_init(&uport->lock);
2760 lockdep_set_class(&uport->lock, &port_lock_key);
2761 }
2762 if (uport->cons && uport->dev)
2763 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2764
2765 uart_configure_port(drv, state, uport);
2766
2767 port->console = uart_console(uport);
2768
2769 num_groups = 2;
2770 if (uport->attr_group)
2771 num_groups++;
2772
2773 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2774 GFP_KERNEL);
2775 if (!uport->tty_groups) {
2776 ret = -ENOMEM;
2777 goto out;
2778 }
2779 uport->tty_groups[0] = &tty_dev_attr_group;
2780 if (uport->attr_group)
2781 uport->tty_groups[1] = uport->attr_group;
2782
2783 /*
2784 * Register the port whether it's detected or not. This allows
2785 * setserial to be used to alter this port's parameters.
2786 */
2787 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2788 uport->line, uport->dev, port, uport->tty_groups);
2789 if (likely(!IS_ERR(tty_dev))) {
2790 device_set_wakeup_capable(tty_dev, 1);
2791 } else {
2792 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2793 uport->line);
2794 }
2795
2796 /*
2797 * Ensure UPF_DEAD is not set.
2798 */
2799 uport->flags &= ~UPF_DEAD;
2800
2801 out:
2802 mutex_unlock(&port->mutex);
2803 mutex_unlock(&port_mutex);
2804
2805 return ret;
2806}
2807
2808/**
2809 * uart_remove_one_port - detach a driver defined port structure
2810 * @drv: pointer to the uart low level driver structure for this port
2811 * @uport: uart port structure for this port
2812 *
2813 * This unhooks (and hangs up) the specified port structure from the
2814 * core driver. No further calls will be made to the low-level code
2815 * for this port.
2816 */
2817int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2818{
2819 struct uart_state *state = drv->state + uport->line;
2820 struct tty_port *port = &state->port;
2821 struct uart_port *uart_port;
2822 struct tty_struct *tty;
2823 int ret = 0;
2824
2825 BUG_ON(in_interrupt());
2826
2827 mutex_lock(&port_mutex);
2828
2829 /*
2830 * Mark the port "dead" - this prevents any opens from
2831 * succeeding while we shut down the port.
2832 */
2833 mutex_lock(&port->mutex);
2834 uart_port = uart_port_check(state);
2835 if (uart_port != uport)
2836 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2837 uart_port, uport);
2838
2839 if (!uart_port) {
2840 mutex_unlock(&port->mutex);
2841 ret = -EINVAL;
2842 goto out;
2843 }
2844 uport->flags |= UPF_DEAD;
2845 mutex_unlock(&port->mutex);
2846
2847 /*
2848 * Remove the devices from the tty layer
2849 */
2850 tty_unregister_device(drv->tty_driver, uport->line);
2851
2852 tty = tty_port_tty_get(port);
2853 if (tty) {
2854 tty_vhangup(port->tty);
2855 tty_kref_put(tty);
2856 }
2857
2858 /*
2859 * If the port is used as a console, unregister it
2860 */
2861 if (uart_console(uport))
2862 unregister_console(uport->cons);
2863
2864 /*
2865 * Free the port IO and memory resources, if any.
2866 */
2867 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
2868 uport->ops->release_port(uport);
2869 kfree(uport->tty_groups);
2870
2871 /*
2872 * Indicate that there isn't a port here anymore.
2873 */
2874 uport->type = PORT_UNKNOWN;
2875
2876 mutex_lock(&port->mutex);
2877 WARN_ON(atomic_dec_return(&state->refcount) < 0);
2878 wait_event(state->remove_wait, !atomic_read(&state->refcount));
2879 state->uart_port = NULL;
2880 mutex_unlock(&port->mutex);
2881out:
2882 mutex_unlock(&port_mutex);
2883
2884 return ret;
2885}
2886
2887/*
2888 * Are the two ports equivalent?
2889 */
2890int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2891{
2892 if (port1->iotype != port2->iotype)
2893 return 0;
2894
2895 switch (port1->iotype) {
2896 case UPIO_PORT:
2897 return (port1->iobase == port2->iobase);
2898 case UPIO_HUB6:
2899 return (port1->iobase == port2->iobase) &&
2900 (port1->hub6 == port2->hub6);
2901 case UPIO_MEM:
2902 case UPIO_MEM16:
2903 case UPIO_MEM32:
2904 case UPIO_MEM32BE:
2905 case UPIO_AU:
2906 case UPIO_TSI:
2907 return (port1->mapbase == port2->mapbase);
2908 }
2909 return 0;
2910}
2911EXPORT_SYMBOL(uart_match_port);
2912
2913/**
2914 * uart_handle_dcd_change - handle a change of carrier detect state
2915 * @uport: uart_port structure for the open port
2916 * @status: new carrier detect status, nonzero if active
2917 *
2918 * Caller must hold uport->lock
2919 */
2920void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2921{
2922 struct tty_port *port = &uport->state->port;
2923 struct tty_struct *tty = port->tty;
2924 struct tty_ldisc *ld;
2925
2926 lockdep_assert_held_once(&uport->lock);
2927
2928 if (tty) {
2929 ld = tty_ldisc_ref(tty);
2930 if (ld) {
2931 if (ld->ops->dcd_change)
2932 ld->ops->dcd_change(tty, status);
2933 tty_ldisc_deref(ld);
2934 }
2935 }
2936
2937 uport->icount.dcd++;
2938
2939 if (uart_dcd_enabled(uport)) {
2940 if (status)
2941 wake_up_interruptible(&port->open_wait);
2942 else if (tty)
2943 tty_hangup(tty);
2944 }
2945}
2946EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2947
2948/**
2949 * uart_handle_cts_change - handle a change of clear-to-send state
2950 * @uport: uart_port structure for the open port
2951 * @status: new clear to send status, nonzero if active
2952 *
2953 * Caller must hold uport->lock
2954 */
2955void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2956{
2957 lockdep_assert_held_once(&uport->lock);
2958
2959 uport->icount.cts++;
2960
2961 if (uart_softcts_mode(uport)) {
2962 if (uport->hw_stopped) {
2963 if (status) {
2964 uport->hw_stopped = 0;
2965 uport->ops->start_tx(uport);
2966 uart_write_wakeup(uport);
2967 }
2968 } else {
2969 if (!status) {
2970 uport->hw_stopped = 1;
2971 uport->ops->stop_tx(uport);
2972 }
2973 }
2974
2975 }
2976}
2977EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2978
2979/**
2980 * uart_insert_char - push a char to the uart layer
2981 *
2982 * User is responsible to call tty_flip_buffer_push when they are done with
2983 * insertion.
2984 *
2985 * @port: corresponding port
2986 * @status: state of the serial port RX buffer (LSR for 8250)
2987 * @overrun: mask of overrun bits in @status
2988 * @ch: character to push
2989 * @flag: flag for the character (see TTY_NORMAL and friends)
2990 */
2991void uart_insert_char(struct uart_port *port, unsigned int status,
2992 unsigned int overrun, unsigned int ch, unsigned int flag)
2993{
2994 struct tty_port *tport = &port->state->port;
2995
2996 if ((status & port->ignore_status_mask & ~overrun) == 0)
2997 if (tty_insert_flip_char(tport, ch, flag) == 0)
2998 ++port->icount.buf_overrun;
2999
3000 /*
3001 * Overrun is special. Since it's reported immediately,
3002 * it doesn't affect the current character.
3003 */
3004 if (status & ~port->ignore_status_mask & overrun)
3005 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
3006 ++port->icount.buf_overrun;
3007}
3008EXPORT_SYMBOL_GPL(uart_insert_char);
3009
3010EXPORT_SYMBOL(uart_write_wakeup);
3011EXPORT_SYMBOL(uart_register_driver);
3012EXPORT_SYMBOL(uart_unregister_driver);
3013EXPORT_SYMBOL(uart_suspend_port);
3014EXPORT_SYMBOL(uart_resume_port);
3015EXPORT_SYMBOL(uart_add_one_port);
3016EXPORT_SYMBOL(uart_remove_one_port);
3017
3018MODULE_DESCRIPTION("Serial driver core");
3019MODULE_LICENSE("GPL");