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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// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Driver core for serial ports
4 *
5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 *
7 * Copyright 1999 ARM Limited
8 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
9 */
10#include <linux/module.h>
11#include <linux/tty.h>
12#include <linux/tty_flip.h>
13#include <linux/slab.h>
14#include <linux/sched/signal.h>
15#include <linux/init.h>
16#include <linux/console.h>
17#include <linux/of.h>
18#include <linux/proc_fs.h>
19#include <linux/seq_file.h>
20#include <linux/device.h>
21#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
22#include <linux/serial_core.h>
23#include <linux/delay.h>
24#include <linux/mutex.h>
25
26#include <linux/irq.h>
27#include <linux/uaccess.h>
28
29/*
30 * This is used to lock changes in serial line configuration.
31 */
32static DEFINE_MUTEX(port_mutex);
33
34/*
35 * lockdep: port->lock is initialized in two places, but we
36 * want only one lock-class:
37 */
38static struct lock_class_key port_lock_key;
39
40#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
41
42static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
43 struct ktermios *old_termios);
44static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
45static void uart_change_pm(struct uart_state *state,
46 enum uart_pm_state pm_state);
47
48static void uart_port_shutdown(struct tty_port *port);
49
50static int uart_dcd_enabled(struct uart_port *uport)
51{
52 return !!(uport->status & UPSTAT_DCD_ENABLE);
53}
54
55static inline struct uart_port *uart_port_ref(struct uart_state *state)
56{
57 if (atomic_add_unless(&state->refcount, 1, 0))
58 return state->uart_port;
59 return NULL;
60}
61
62static inline void uart_port_deref(struct uart_port *uport)
63{
64 if (atomic_dec_and_test(&uport->state->refcount))
65 wake_up(&uport->state->remove_wait);
66}
67
68#define uart_port_lock(state, flags) \
69 ({ \
70 struct uart_port *__uport = uart_port_ref(state); \
71 if (__uport) \
72 spin_lock_irqsave(&__uport->lock, flags); \
73 __uport; \
74 })
75
76#define uart_port_unlock(uport, flags) \
77 ({ \
78 struct uart_port *__uport = uport; \
79 if (__uport) { \
80 spin_unlock_irqrestore(&__uport->lock, flags); \
81 uart_port_deref(__uport); \
82 } \
83 })
84
85static inline struct uart_port *uart_port_check(struct uart_state *state)
86{
87 lockdep_assert_held(&state->port.mutex);
88 return state->uart_port;
89}
90
91/*
92 * This routine is used by the interrupt handler to schedule processing in
93 * the software interrupt portion of the driver.
94 */
95void uart_write_wakeup(struct uart_port *port)
96{
97 struct uart_state *state = port->state;
98 /*
99 * This means you called this function _after_ the port was
100 * closed. No cookie for you.
101 */
102 BUG_ON(!state);
103 tty_port_tty_wakeup(&state->port);
104}
105
106static void uart_stop(struct tty_struct *tty)
107{
108 struct uart_state *state = tty->driver_data;
109 struct uart_port *port;
110 unsigned long flags;
111
112 port = uart_port_lock(state, flags);
113 if (port)
114 port->ops->stop_tx(port);
115 uart_port_unlock(port, flags);
116}
117
118static void __uart_start(struct tty_struct *tty)
119{
120 struct uart_state *state = tty->driver_data;
121 struct uart_port *port = state->uart_port;
122
123 if (port && !uart_tx_stopped(port))
124 port->ops->start_tx(port);
125}
126
127static void uart_start(struct tty_struct *tty)
128{
129 struct uart_state *state = tty->driver_data;
130 struct uart_port *port;
131 unsigned long flags;
132
133 port = uart_port_lock(state, flags);
134 __uart_start(tty);
135 uart_port_unlock(port, flags);
136}
137
138static void
139uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
140{
141 unsigned long flags;
142 unsigned int old;
143
144 spin_lock_irqsave(&port->lock, flags);
145 old = port->mctrl;
146 port->mctrl = (old & ~clear) | set;
147 if (old != port->mctrl)
148 port->ops->set_mctrl(port, port->mctrl);
149 spin_unlock_irqrestore(&port->lock, flags);
150}
151
152#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
153#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
154
155static void uart_port_dtr_rts(struct uart_port *uport, int raise)
156{
157 int rs485_on = uport->rs485_config &&
158 (uport->rs485.flags & SER_RS485_ENABLED);
159 int RTS_after_send = !!(uport->rs485.flags & SER_RS485_RTS_AFTER_SEND);
160
161 if (raise) {
162 if (rs485_on && !RTS_after_send) {
163 uart_set_mctrl(uport, TIOCM_DTR);
164 uart_clear_mctrl(uport, TIOCM_RTS);
165 } else {
166 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
167 }
168 } else {
169 unsigned int clear = TIOCM_DTR;
170
171 clear |= (!rs485_on || !RTS_after_send) ? TIOCM_RTS : 0;
172 uart_clear_mctrl(uport, clear);
173 }
174}
175
176/*
177 * Startup the port. This will be called once per open. All calls
178 * will be serialised by the per-port mutex.
179 */
180static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
181 int init_hw)
182{
183 struct uart_port *uport = uart_port_check(state);
184 unsigned long page;
185 int retval = 0;
186
187 if (uport->type == PORT_UNKNOWN)
188 return 1;
189
190 /*
191 * Make sure the device is in D0 state.
192 */
193 uart_change_pm(state, UART_PM_STATE_ON);
194
195 /*
196 * Initialise and allocate the transmit and temporary
197 * buffer.
198 */
199 if (!state->xmit.buf) {
200 /* This is protected by the per port mutex */
201 page = get_zeroed_page(GFP_KERNEL);
202 if (!page)
203 return -ENOMEM;
204
205 state->xmit.buf = (unsigned char *) page;
206 uart_circ_clear(&state->xmit);
207 }
208
209 retval = uport->ops->startup(uport);
210 if (retval == 0) {
211 if (uart_console(uport) && uport->cons->cflag) {
212 tty->termios.c_cflag = uport->cons->cflag;
213 uport->cons->cflag = 0;
214 }
215 /*
216 * Initialise the hardware port settings.
217 */
218 uart_change_speed(tty, state, NULL);
219
220 /*
221 * Setup the RTS and DTR signals once the
222 * port is open and ready to respond.
223 */
224 if (init_hw && C_BAUD(tty))
225 uart_port_dtr_rts(uport, 1);
226 }
227
228 /*
229 * This is to allow setserial on this port. People may want to set
230 * port/irq/type and then reconfigure the port properly if it failed
231 * now.
232 */
233 if (retval && capable(CAP_SYS_ADMIN))
234 return 1;
235
236 return retval;
237}
238
239static int uart_startup(struct tty_struct *tty, struct uart_state *state,
240 int init_hw)
241{
242 struct tty_port *port = &state->port;
243 int retval;
244
245 if (tty_port_initialized(port))
246 return 0;
247
248 retval = uart_port_startup(tty, state, init_hw);
249 if (retval)
250 set_bit(TTY_IO_ERROR, &tty->flags);
251
252 return retval;
253}
254
255/*
256 * This routine will shutdown a serial port; interrupts are disabled, and
257 * DTR is dropped if the hangup on close termio flag is on. Calls to
258 * uart_shutdown are serialised by the per-port semaphore.
259 *
260 * uport == NULL if uart_port has already been removed
261 */
262static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
263{
264 struct uart_port *uport = uart_port_check(state);
265 struct tty_port *port = &state->port;
266
267 /*
268 * Set the TTY IO error marker
269 */
270 if (tty)
271 set_bit(TTY_IO_ERROR, &tty->flags);
272
273 if (tty_port_initialized(port)) {
274 tty_port_set_initialized(port, 0);
275
276 /*
277 * Turn off DTR and RTS early.
278 */
279 if (uport && uart_console(uport) && tty)
280 uport->cons->cflag = tty->termios.c_cflag;
281
282 if (!tty || C_HUPCL(tty))
283 uart_port_dtr_rts(uport, 0);
284
285 uart_port_shutdown(port);
286 }
287
288 /*
289 * It's possible for shutdown to be called after suspend if we get
290 * a DCD drop (hangup) at just the right time. Clear suspended bit so
291 * we don't try to resume a port that has been shutdown.
292 */
293 tty_port_set_suspended(port, 0);
294
295 /*
296 * Free the transmit buffer page.
297 */
298 if (state->xmit.buf) {
299 free_page((unsigned long)state->xmit.buf);
300 state->xmit.buf = NULL;
301 }
302}
303
304/**
305 * uart_update_timeout - update per-port FIFO timeout.
306 * @port: uart_port structure describing the port
307 * @cflag: termios cflag value
308 * @baud: speed of the port
309 *
310 * Set the port FIFO timeout value. The @cflag value should
311 * reflect the actual hardware settings.
312 */
313void
314uart_update_timeout(struct uart_port *port, unsigned int cflag,
315 unsigned int baud)
316{
317 unsigned int bits;
318
319 /* byte size and parity */
320 switch (cflag & CSIZE) {
321 case CS5:
322 bits = 7;
323 break;
324 case CS6:
325 bits = 8;
326 break;
327 case CS7:
328 bits = 9;
329 break;
330 default:
331 bits = 10;
332 break; /* CS8 */
333 }
334
335 if (cflag & CSTOPB)
336 bits++;
337 if (cflag & PARENB)
338 bits++;
339
340 /*
341 * The total number of bits to be transmitted in the fifo.
342 */
343 bits = bits * port->fifosize;
344
345 /*
346 * Figure the timeout to send the above number of bits.
347 * Add .02 seconds of slop
348 */
349 port->timeout = (HZ * bits) / baud + HZ/50;
350}
351
352EXPORT_SYMBOL(uart_update_timeout);
353
354/**
355 * uart_get_baud_rate - return baud rate for a particular port
356 * @port: uart_port structure describing the port in question.
357 * @termios: desired termios settings.
358 * @old: old termios (or NULL)
359 * @min: minimum acceptable baud rate
360 * @max: maximum acceptable baud rate
361 *
362 * Decode the termios structure into a numeric baud rate,
363 * taking account of the magic 38400 baud rate (with spd_*
364 * flags), and mapping the %B0 rate to 9600 baud.
365 *
366 * If the new baud rate is invalid, try the old termios setting.
367 * If it's still invalid, we try 9600 baud.
368 *
369 * Update the @termios structure to reflect the baud rate
370 * we're actually going to be using. Don't do this for the case
371 * where B0 is requested ("hang up").
372 */
373unsigned int
374uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
375 struct ktermios *old, unsigned int min, unsigned int max)
376{
377 unsigned int try;
378 unsigned int baud;
379 unsigned int altbaud;
380 int hung_up = 0;
381 upf_t flags = port->flags & UPF_SPD_MASK;
382
383 switch (flags) {
384 case UPF_SPD_HI:
385 altbaud = 57600;
386 break;
387 case UPF_SPD_VHI:
388 altbaud = 115200;
389 break;
390 case UPF_SPD_SHI:
391 altbaud = 230400;
392 break;
393 case UPF_SPD_WARP:
394 altbaud = 460800;
395 break;
396 default:
397 altbaud = 38400;
398 break;
399 }
400
401 for (try = 0; try < 2; try++) {
402 baud = tty_termios_baud_rate(termios);
403
404 /*
405 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
406 * Die! Die! Die!
407 */
408 if (try == 0 && baud == 38400)
409 baud = altbaud;
410
411 /*
412 * Special case: B0 rate.
413 */
414 if (baud == 0) {
415 hung_up = 1;
416 baud = 9600;
417 }
418
419 if (baud >= min && baud <= max)
420 return baud;
421
422 /*
423 * Oops, the quotient was zero. Try again with
424 * the old baud rate if possible.
425 */
426 termios->c_cflag &= ~CBAUD;
427 if (old) {
428 baud = tty_termios_baud_rate(old);
429 if (!hung_up)
430 tty_termios_encode_baud_rate(termios,
431 baud, baud);
432 old = NULL;
433 continue;
434 }
435
436 /*
437 * As a last resort, if the range cannot be met then clip to
438 * the nearest chip supported rate.
439 */
440 if (!hung_up) {
441 if (baud <= min)
442 tty_termios_encode_baud_rate(termios,
443 min + 1, min + 1);
444 else
445 tty_termios_encode_baud_rate(termios,
446 max - 1, max - 1);
447 }
448 }
449 /* Should never happen */
450 WARN_ON(1);
451 return 0;
452}
453
454EXPORT_SYMBOL(uart_get_baud_rate);
455
456/**
457 * uart_get_divisor - return uart clock divisor
458 * @port: uart_port structure describing the port.
459 * @baud: desired baud rate
460 *
461 * Calculate the uart clock divisor for the port.
462 */
463unsigned int
464uart_get_divisor(struct uart_port *port, unsigned int baud)
465{
466 unsigned int quot;
467
468 /*
469 * Old custom speed handling.
470 */
471 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
472 quot = port->custom_divisor;
473 else
474 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
475
476 return quot;
477}
478
479EXPORT_SYMBOL(uart_get_divisor);
480
481/* Caller holds port mutex */
482static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
483 struct ktermios *old_termios)
484{
485 struct uart_port *uport = uart_port_check(state);
486 struct ktermios *termios;
487 int hw_stopped;
488
489 /*
490 * If we have no tty, termios, or the port does not exist,
491 * then we can't set the parameters for this port.
492 */
493 if (!tty || uport->type == PORT_UNKNOWN)
494 return;
495
496 termios = &tty->termios;
497 uport->ops->set_termios(uport, termios, old_termios);
498
499 /*
500 * Set modem status enables based on termios cflag
501 */
502 spin_lock_irq(&uport->lock);
503 if (termios->c_cflag & CRTSCTS)
504 uport->status |= UPSTAT_CTS_ENABLE;
505 else
506 uport->status &= ~UPSTAT_CTS_ENABLE;
507
508 if (termios->c_cflag & CLOCAL)
509 uport->status &= ~UPSTAT_DCD_ENABLE;
510 else
511 uport->status |= UPSTAT_DCD_ENABLE;
512
513 /* reset sw-assisted CTS flow control based on (possibly) new mode */
514 hw_stopped = uport->hw_stopped;
515 uport->hw_stopped = uart_softcts_mode(uport) &&
516 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
517 if (uport->hw_stopped) {
518 if (!hw_stopped)
519 uport->ops->stop_tx(uport);
520 } else {
521 if (hw_stopped)
522 __uart_start(tty);
523 }
524 spin_unlock_irq(&uport->lock);
525}
526
527static int uart_put_char(struct tty_struct *tty, unsigned char c)
528{
529 struct uart_state *state = tty->driver_data;
530 struct uart_port *port;
531 struct circ_buf *circ;
532 unsigned long flags;
533 int ret = 0;
534
535 circ = &state->xmit;
536 if (!circ->buf)
537 return 0;
538
539 port = uart_port_lock(state, flags);
540 if (port && uart_circ_chars_free(circ) != 0) {
541 circ->buf[circ->head] = c;
542 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
543 ret = 1;
544 }
545 uart_port_unlock(port, flags);
546 return ret;
547}
548
549static void uart_flush_chars(struct tty_struct *tty)
550{
551 uart_start(tty);
552}
553
554static int uart_write(struct tty_struct *tty,
555 const unsigned char *buf, int count)
556{
557 struct uart_state *state = tty->driver_data;
558 struct uart_port *port;
559 struct circ_buf *circ;
560 unsigned long flags;
561 int c, ret = 0;
562
563 /*
564 * This means you called this function _after_ the port was
565 * closed. No cookie for you.
566 */
567 if (!state) {
568 WARN_ON(1);
569 return -EL3HLT;
570 }
571
572 circ = &state->xmit;
573 if (!circ->buf)
574 return 0;
575
576 port = uart_port_lock(state, flags);
577 while (port) {
578 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
579 if (count < c)
580 c = count;
581 if (c <= 0)
582 break;
583 memcpy(circ->buf + circ->head, buf, c);
584 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
585 buf += c;
586 count -= c;
587 ret += c;
588 }
589
590 __uart_start(tty);
591 uart_port_unlock(port, flags);
592 return ret;
593}
594
595static int uart_write_room(struct tty_struct *tty)
596{
597 struct uart_state *state = tty->driver_data;
598 struct uart_port *port;
599 unsigned long flags;
600 int ret;
601
602 port = uart_port_lock(state, flags);
603 ret = uart_circ_chars_free(&state->xmit);
604 uart_port_unlock(port, flags);
605 return ret;
606}
607
608static int uart_chars_in_buffer(struct tty_struct *tty)
609{
610 struct uart_state *state = tty->driver_data;
611 struct uart_port *port;
612 unsigned long flags;
613 int ret;
614
615 port = uart_port_lock(state, flags);
616 ret = uart_circ_chars_pending(&state->xmit);
617 uart_port_unlock(port, flags);
618 return ret;
619}
620
621static void uart_flush_buffer(struct tty_struct *tty)
622{
623 struct uart_state *state = tty->driver_data;
624 struct uart_port *port;
625 unsigned long flags;
626
627 /*
628 * This means you called this function _after_ the port was
629 * closed. No cookie for you.
630 */
631 if (!state) {
632 WARN_ON(1);
633 return;
634 }
635
636 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
637
638 port = uart_port_lock(state, flags);
639 if (!port)
640 return;
641 uart_circ_clear(&state->xmit);
642 if (port->ops->flush_buffer)
643 port->ops->flush_buffer(port);
644 uart_port_unlock(port, flags);
645 tty_port_tty_wakeup(&state->port);
646}
647
648/*
649 * This function is used to send a high-priority XON/XOFF character to
650 * the device
651 */
652static void uart_send_xchar(struct tty_struct *tty, char ch)
653{
654 struct uart_state *state = tty->driver_data;
655 struct uart_port *port;
656 unsigned long flags;
657
658 port = uart_port_ref(state);
659 if (!port)
660 return;
661
662 if (port->ops->send_xchar)
663 port->ops->send_xchar(port, ch);
664 else {
665 spin_lock_irqsave(&port->lock, flags);
666 port->x_char = ch;
667 if (ch)
668 port->ops->start_tx(port);
669 spin_unlock_irqrestore(&port->lock, flags);
670 }
671 uart_port_deref(port);
672}
673
674static void uart_throttle(struct tty_struct *tty)
675{
676 struct uart_state *state = tty->driver_data;
677 struct uart_port *port;
678 upstat_t mask = 0;
679
680 port = uart_port_ref(state);
681 if (!port)
682 return;
683
684 if (I_IXOFF(tty))
685 mask |= UPSTAT_AUTOXOFF;
686 if (C_CRTSCTS(tty))
687 mask |= UPSTAT_AUTORTS;
688
689 if (port->status & mask) {
690 port->ops->throttle(port);
691 mask &= ~port->status;
692 }
693
694 if (mask & UPSTAT_AUTORTS)
695 uart_clear_mctrl(port, TIOCM_RTS);
696
697 if (mask & UPSTAT_AUTOXOFF)
698 uart_send_xchar(tty, STOP_CHAR(tty));
699
700 uart_port_deref(port);
701}
702
703static void uart_unthrottle(struct tty_struct *tty)
704{
705 struct uart_state *state = tty->driver_data;
706 struct uart_port *port;
707 upstat_t mask = 0;
708
709 port = uart_port_ref(state);
710 if (!port)
711 return;
712
713 if (I_IXOFF(tty))
714 mask |= UPSTAT_AUTOXOFF;
715 if (C_CRTSCTS(tty))
716 mask |= UPSTAT_AUTORTS;
717
718 if (port->status & mask) {
719 port->ops->unthrottle(port);
720 mask &= ~port->status;
721 }
722
723 if (mask & UPSTAT_AUTORTS)
724 uart_set_mctrl(port, TIOCM_RTS);
725
726 if (mask & UPSTAT_AUTOXOFF)
727 uart_send_xchar(tty, START_CHAR(tty));
728
729 uart_port_deref(port);
730}
731
732static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
733{
734 struct uart_state *state = container_of(port, struct uart_state, port);
735 struct uart_port *uport;
736 int ret = -ENODEV;
737
738 memset(retinfo, 0, sizeof(*retinfo));
739
740 /*
741 * Ensure the state we copy is consistent and no hardware changes
742 * occur as we go
743 */
744 mutex_lock(&port->mutex);
745 uport = uart_port_check(state);
746 if (!uport)
747 goto out;
748
749 retinfo->type = uport->type;
750 retinfo->line = uport->line;
751 retinfo->port = uport->iobase;
752 if (HIGH_BITS_OFFSET)
753 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
754 retinfo->irq = uport->irq;
755 retinfo->flags = (__force int)uport->flags;
756 retinfo->xmit_fifo_size = uport->fifosize;
757 retinfo->baud_base = uport->uartclk / 16;
758 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
759 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
760 ASYNC_CLOSING_WAIT_NONE :
761 jiffies_to_msecs(port->closing_wait) / 10;
762 retinfo->custom_divisor = uport->custom_divisor;
763 retinfo->hub6 = uport->hub6;
764 retinfo->io_type = uport->iotype;
765 retinfo->iomem_reg_shift = uport->regshift;
766 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
767
768 ret = 0;
769out:
770 mutex_unlock(&port->mutex);
771 return ret;
772}
773
774static int uart_get_info_user(struct tty_port *port,
775 struct serial_struct __user *retinfo)
776{
777 struct serial_struct tmp;
778
779 if (uart_get_info(port, &tmp) < 0)
780 return -EIO;
781
782 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
783 return -EFAULT;
784 return 0;
785}
786
787static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
788 struct uart_state *state,
789 struct serial_struct *new_info)
790{
791 struct uart_port *uport = uart_port_check(state);
792 unsigned long new_port;
793 unsigned int change_irq, change_port, closing_wait;
794 unsigned int old_custom_divisor, close_delay;
795 upf_t old_flags, new_flags;
796 int retval = 0;
797
798 if (!uport)
799 return -EIO;
800
801 new_port = new_info->port;
802 if (HIGH_BITS_OFFSET)
803 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
804
805 new_info->irq = irq_canonicalize(new_info->irq);
806 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
807 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
808 ASYNC_CLOSING_WAIT_NONE :
809 msecs_to_jiffies(new_info->closing_wait * 10);
810
811
812 change_irq = !(uport->flags & UPF_FIXED_PORT)
813 && new_info->irq != uport->irq;
814
815 /*
816 * Since changing the 'type' of the port changes its resource
817 * allocations, we should treat type changes the same as
818 * IO port changes.
819 */
820 change_port = !(uport->flags & UPF_FIXED_PORT)
821 && (new_port != uport->iobase ||
822 (unsigned long)new_info->iomem_base != uport->mapbase ||
823 new_info->hub6 != uport->hub6 ||
824 new_info->io_type != uport->iotype ||
825 new_info->iomem_reg_shift != uport->regshift ||
826 new_info->type != uport->type);
827
828 old_flags = uport->flags;
829 new_flags = (__force upf_t)new_info->flags;
830 old_custom_divisor = uport->custom_divisor;
831
832 if (!capable(CAP_SYS_ADMIN)) {
833 retval = -EPERM;
834 if (change_irq || change_port ||
835 (new_info->baud_base != uport->uartclk / 16) ||
836 (close_delay != port->close_delay) ||
837 (closing_wait != port->closing_wait) ||
838 (new_info->xmit_fifo_size &&
839 new_info->xmit_fifo_size != uport->fifosize) ||
840 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
841 goto exit;
842 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
843 (new_flags & UPF_USR_MASK));
844 uport->custom_divisor = new_info->custom_divisor;
845 goto check_and_exit;
846 }
847
848 /*
849 * Ask the low level driver to verify the settings.
850 */
851 if (uport->ops->verify_port)
852 retval = uport->ops->verify_port(uport, new_info);
853
854 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
855 (new_info->baud_base < 9600))
856 retval = -EINVAL;
857
858 if (retval)
859 goto exit;
860
861 if (change_port || change_irq) {
862 retval = -EBUSY;
863
864 /*
865 * Make sure that we are the sole user of this port.
866 */
867 if (tty_port_users(port) > 1)
868 goto exit;
869
870 /*
871 * We need to shutdown the serial port at the old
872 * port/type/irq combination.
873 */
874 uart_shutdown(tty, state);
875 }
876
877 if (change_port) {
878 unsigned long old_iobase, old_mapbase;
879 unsigned int old_type, old_iotype, old_hub6, old_shift;
880
881 old_iobase = uport->iobase;
882 old_mapbase = uport->mapbase;
883 old_type = uport->type;
884 old_hub6 = uport->hub6;
885 old_iotype = uport->iotype;
886 old_shift = uport->regshift;
887
888 /*
889 * Free and release old regions
890 */
891 if (old_type != PORT_UNKNOWN && uport->ops->release_port)
892 uport->ops->release_port(uport);
893
894 uport->iobase = new_port;
895 uport->type = new_info->type;
896 uport->hub6 = new_info->hub6;
897 uport->iotype = new_info->io_type;
898 uport->regshift = new_info->iomem_reg_shift;
899 uport->mapbase = (unsigned long)new_info->iomem_base;
900
901 /*
902 * Claim and map the new regions
903 */
904 if (uport->type != PORT_UNKNOWN && uport->ops->request_port) {
905 retval = uport->ops->request_port(uport);
906 } else {
907 /* Always success - Jean II */
908 retval = 0;
909 }
910
911 /*
912 * If we fail to request resources for the
913 * new port, try to restore the old settings.
914 */
915 if (retval) {
916 uport->iobase = old_iobase;
917 uport->type = old_type;
918 uport->hub6 = old_hub6;
919 uport->iotype = old_iotype;
920 uport->regshift = old_shift;
921 uport->mapbase = old_mapbase;
922
923 if (old_type != PORT_UNKNOWN) {
924 retval = uport->ops->request_port(uport);
925 /*
926 * If we failed to restore the old settings,
927 * we fail like this.
928 */
929 if (retval)
930 uport->type = PORT_UNKNOWN;
931
932 /*
933 * We failed anyway.
934 */
935 retval = -EBUSY;
936 }
937
938 /* Added to return the correct error -Ram Gupta */
939 goto exit;
940 }
941 }
942
943 if (change_irq)
944 uport->irq = new_info->irq;
945 if (!(uport->flags & UPF_FIXED_PORT))
946 uport->uartclk = new_info->baud_base * 16;
947 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
948 (new_flags & UPF_CHANGE_MASK);
949 uport->custom_divisor = new_info->custom_divisor;
950 port->close_delay = close_delay;
951 port->closing_wait = closing_wait;
952 if (new_info->xmit_fifo_size)
953 uport->fifosize = new_info->xmit_fifo_size;
954 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
955
956 check_and_exit:
957 retval = 0;
958 if (uport->type == PORT_UNKNOWN)
959 goto exit;
960 if (tty_port_initialized(port)) {
961 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
962 old_custom_divisor != uport->custom_divisor) {
963 /*
964 * If they're setting up a custom divisor or speed,
965 * instead of clearing it, then bitch about it.
966 */
967 if (uport->flags & UPF_SPD_MASK) {
968 dev_notice_ratelimited(uport->dev,
969 "%s sets custom speed on %s. This is deprecated.\n",
970 current->comm,
971 tty_name(port->tty));
972 }
973 uart_change_speed(tty, state, NULL);
974 }
975 } else {
976 retval = uart_startup(tty, state, 1);
977 if (retval == 0)
978 tty_port_set_initialized(port, true);
979 if (retval > 0)
980 retval = 0;
981 }
982 exit:
983 return retval;
984}
985
986static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
987 struct serial_struct __user *newinfo)
988{
989 struct serial_struct new_serial;
990 struct tty_port *port = &state->port;
991 int retval;
992
993 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
994 return -EFAULT;
995
996 /*
997 * This semaphore protects port->count. It is also
998 * very useful to prevent opens. Also, take the
999 * port configuration semaphore to make sure that a
1000 * module insertion/removal doesn't change anything
1001 * under us.
1002 */
1003 mutex_lock(&port->mutex);
1004 retval = uart_set_info(tty, port, state, &new_serial);
1005 mutex_unlock(&port->mutex);
1006 return retval;
1007}
1008
1009/**
1010 * uart_get_lsr_info - get line status register info
1011 * @tty: tty associated with the UART
1012 * @state: UART being queried
1013 * @value: returned modem value
1014 */
1015static int uart_get_lsr_info(struct tty_struct *tty,
1016 struct uart_state *state, unsigned int __user *value)
1017{
1018 struct uart_port *uport = uart_port_check(state);
1019 unsigned int result;
1020
1021 result = uport->ops->tx_empty(uport);
1022
1023 /*
1024 * If we're about to load something into the transmit
1025 * register, we'll pretend the transmitter isn't empty to
1026 * avoid a race condition (depending on when the transmit
1027 * interrupt happens).
1028 */
1029 if (uport->x_char ||
1030 ((uart_circ_chars_pending(&state->xmit) > 0) &&
1031 !uart_tx_stopped(uport)))
1032 result &= ~TIOCSER_TEMT;
1033
1034 return put_user(result, value);
1035}
1036
1037static int uart_tiocmget(struct tty_struct *tty)
1038{
1039 struct uart_state *state = tty->driver_data;
1040 struct tty_port *port = &state->port;
1041 struct uart_port *uport;
1042 int result = -EIO;
1043
1044 mutex_lock(&port->mutex);
1045 uport = uart_port_check(state);
1046 if (!uport)
1047 goto out;
1048
1049 if (!tty_io_error(tty)) {
1050 result = uport->mctrl;
1051 spin_lock_irq(&uport->lock);
1052 result |= uport->ops->get_mctrl(uport);
1053 spin_unlock_irq(&uport->lock);
1054 }
1055out:
1056 mutex_unlock(&port->mutex);
1057 return result;
1058}
1059
1060static int
1061uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
1062{
1063 struct uart_state *state = tty->driver_data;
1064 struct tty_port *port = &state->port;
1065 struct uart_port *uport;
1066 int ret = -EIO;
1067
1068 mutex_lock(&port->mutex);
1069 uport = uart_port_check(state);
1070 if (!uport)
1071 goto out;
1072
1073 if (!tty_io_error(tty)) {
1074 uart_update_mctrl(uport, set, clear);
1075 ret = 0;
1076 }
1077out:
1078 mutex_unlock(&port->mutex);
1079 return ret;
1080}
1081
1082static int uart_break_ctl(struct tty_struct *tty, int break_state)
1083{
1084 struct uart_state *state = tty->driver_data;
1085 struct tty_port *port = &state->port;
1086 struct uart_port *uport;
1087 int ret = -EIO;
1088
1089 mutex_lock(&port->mutex);
1090 uport = uart_port_check(state);
1091 if (!uport)
1092 goto out;
1093
1094 if (uport->type != PORT_UNKNOWN)
1095 uport->ops->break_ctl(uport, break_state);
1096 ret = 0;
1097out:
1098 mutex_unlock(&port->mutex);
1099 return ret;
1100}
1101
1102static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1103{
1104 struct tty_port *port = &state->port;
1105 struct uart_port *uport;
1106 int flags, ret;
1107
1108 if (!capable(CAP_SYS_ADMIN))
1109 return -EPERM;
1110
1111 /*
1112 * Take the per-port semaphore. This prevents count from
1113 * changing, and hence any extra opens of the port while
1114 * we're auto-configuring.
1115 */
1116 if (mutex_lock_interruptible(&port->mutex))
1117 return -ERESTARTSYS;
1118
1119 uport = uart_port_check(state);
1120 if (!uport) {
1121 ret = -EIO;
1122 goto out;
1123 }
1124
1125 ret = -EBUSY;
1126 if (tty_port_users(port) == 1) {
1127 uart_shutdown(tty, state);
1128
1129 /*
1130 * If we already have a port type configured,
1131 * we must release its resources.
1132 */
1133 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
1134 uport->ops->release_port(uport);
1135
1136 flags = UART_CONFIG_TYPE;
1137 if (uport->flags & UPF_AUTO_IRQ)
1138 flags |= UART_CONFIG_IRQ;
1139
1140 /*
1141 * This will claim the ports resources if
1142 * a port is found.
1143 */
1144 uport->ops->config_port(uport, flags);
1145
1146 ret = uart_startup(tty, state, 1);
1147 if (ret == 0)
1148 tty_port_set_initialized(port, true);
1149 if (ret > 0)
1150 ret = 0;
1151 }
1152out:
1153 mutex_unlock(&port->mutex);
1154 return ret;
1155}
1156
1157static void uart_enable_ms(struct uart_port *uport)
1158{
1159 /*
1160 * Force modem status interrupts on
1161 */
1162 if (uport->ops->enable_ms)
1163 uport->ops->enable_ms(uport);
1164}
1165
1166/*
1167 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1168 * - mask passed in arg for lines of interest
1169 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1170 * Caller should use TIOCGICOUNT to see which one it was
1171 *
1172 * FIXME: This wants extracting into a common all driver implementation
1173 * of TIOCMWAIT using tty_port.
1174 */
1175static int uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1176{
1177 struct uart_port *uport;
1178 struct tty_port *port = &state->port;
1179 DECLARE_WAITQUEUE(wait, current);
1180 struct uart_icount cprev, cnow;
1181 int ret;
1182
1183 /*
1184 * note the counters on entry
1185 */
1186 uport = uart_port_ref(state);
1187 if (!uport)
1188 return -EIO;
1189 spin_lock_irq(&uport->lock);
1190 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1191 uart_enable_ms(uport);
1192 spin_unlock_irq(&uport->lock);
1193
1194 add_wait_queue(&port->delta_msr_wait, &wait);
1195 for (;;) {
1196 spin_lock_irq(&uport->lock);
1197 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1198 spin_unlock_irq(&uport->lock);
1199
1200 set_current_state(TASK_INTERRUPTIBLE);
1201
1202 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1203 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1204 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1205 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1206 ret = 0;
1207 break;
1208 }
1209
1210 schedule();
1211
1212 /* see if a signal did it */
1213 if (signal_pending(current)) {
1214 ret = -ERESTARTSYS;
1215 break;
1216 }
1217
1218 cprev = cnow;
1219 }
1220 __set_current_state(TASK_RUNNING);
1221 remove_wait_queue(&port->delta_msr_wait, &wait);
1222 uart_port_deref(uport);
1223
1224 return ret;
1225}
1226
1227/*
1228 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1229 * Return: write counters to the user passed counter struct
1230 * NB: both 1->0 and 0->1 transitions are counted except for
1231 * RI where only 0->1 is counted.
1232 */
1233static int uart_get_icount(struct tty_struct *tty,
1234 struct serial_icounter_struct *icount)
1235{
1236 struct uart_state *state = tty->driver_data;
1237 struct uart_icount cnow;
1238 struct uart_port *uport;
1239
1240 uport = uart_port_ref(state);
1241 if (!uport)
1242 return -EIO;
1243 spin_lock_irq(&uport->lock);
1244 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1245 spin_unlock_irq(&uport->lock);
1246 uart_port_deref(uport);
1247
1248 icount->cts = cnow.cts;
1249 icount->dsr = cnow.dsr;
1250 icount->rng = cnow.rng;
1251 icount->dcd = cnow.dcd;
1252 icount->rx = cnow.rx;
1253 icount->tx = cnow.tx;
1254 icount->frame = cnow.frame;
1255 icount->overrun = cnow.overrun;
1256 icount->parity = cnow.parity;
1257 icount->brk = cnow.brk;
1258 icount->buf_overrun = cnow.buf_overrun;
1259
1260 return 0;
1261}
1262
1263static int uart_get_rs485_config(struct uart_port *port,
1264 struct serial_rs485 __user *rs485)
1265{
1266 unsigned long flags;
1267 struct serial_rs485 aux;
1268
1269 spin_lock_irqsave(&port->lock, flags);
1270 aux = port->rs485;
1271 spin_unlock_irqrestore(&port->lock, flags);
1272
1273 if (copy_to_user(rs485, &aux, sizeof(aux)))
1274 return -EFAULT;
1275
1276 return 0;
1277}
1278
1279static int uart_set_rs485_config(struct uart_port *port,
1280 struct serial_rs485 __user *rs485_user)
1281{
1282 struct serial_rs485 rs485;
1283 int ret;
1284 unsigned long flags;
1285
1286 if (!port->rs485_config)
1287 return -ENOIOCTLCMD;
1288
1289 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1290 return -EFAULT;
1291
1292 spin_lock_irqsave(&port->lock, flags);
1293 ret = port->rs485_config(port, &rs485);
1294 spin_unlock_irqrestore(&port->lock, flags);
1295 if (ret)
1296 return ret;
1297
1298 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1299 return -EFAULT;
1300
1301 return 0;
1302}
1303
1304/*
1305 * Called via sys_ioctl. We can use spin_lock_irq() here.
1306 */
1307static int
1308uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
1309{
1310 struct uart_state *state = tty->driver_data;
1311 struct tty_port *port = &state->port;
1312 struct uart_port *uport;
1313 void __user *uarg = (void __user *)arg;
1314 int ret = -ENOIOCTLCMD;
1315
1316
1317 /*
1318 * These ioctls don't rely on the hardware to be present.
1319 */
1320 switch (cmd) {
1321 case TIOCGSERIAL:
1322 ret = uart_get_info_user(port, uarg);
1323 break;
1324
1325 case TIOCSSERIAL:
1326 down_write(&tty->termios_rwsem);
1327 ret = uart_set_info_user(tty, state, uarg);
1328 up_write(&tty->termios_rwsem);
1329 break;
1330
1331 case TIOCSERCONFIG:
1332 down_write(&tty->termios_rwsem);
1333 ret = uart_do_autoconfig(tty, state);
1334 up_write(&tty->termios_rwsem);
1335 break;
1336
1337 case TIOCSERGWILD: /* obsolete */
1338 case TIOCSERSWILD: /* obsolete */
1339 ret = 0;
1340 break;
1341 }
1342
1343 if (ret != -ENOIOCTLCMD)
1344 goto out;
1345
1346 if (tty_io_error(tty)) {
1347 ret = -EIO;
1348 goto out;
1349 }
1350
1351 /*
1352 * The following should only be used when hardware is present.
1353 */
1354 switch (cmd) {
1355 case TIOCMIWAIT:
1356 ret = uart_wait_modem_status(state, arg);
1357 break;
1358 }
1359
1360 if (ret != -ENOIOCTLCMD)
1361 goto out;
1362
1363 mutex_lock(&port->mutex);
1364 uport = uart_port_check(state);
1365
1366 if (!uport || tty_io_error(tty)) {
1367 ret = -EIO;
1368 goto out_up;
1369 }
1370
1371 /*
1372 * All these rely on hardware being present and need to be
1373 * protected against the tty being hung up.
1374 */
1375
1376 switch (cmd) {
1377 case TIOCSERGETLSR: /* Get line status register */
1378 ret = uart_get_lsr_info(tty, state, uarg);
1379 break;
1380
1381 case TIOCGRS485:
1382 ret = uart_get_rs485_config(uport, uarg);
1383 break;
1384
1385 case TIOCSRS485:
1386 ret = uart_set_rs485_config(uport, uarg);
1387 break;
1388 default:
1389 if (uport->ops->ioctl)
1390 ret = uport->ops->ioctl(uport, cmd, arg);
1391 break;
1392 }
1393out_up:
1394 mutex_unlock(&port->mutex);
1395out:
1396 return ret;
1397}
1398
1399static void uart_set_ldisc(struct tty_struct *tty)
1400{
1401 struct uart_state *state = tty->driver_data;
1402 struct uart_port *uport;
1403
1404 mutex_lock(&state->port.mutex);
1405 uport = uart_port_check(state);
1406 if (uport && uport->ops->set_ldisc)
1407 uport->ops->set_ldisc(uport, &tty->termios);
1408 mutex_unlock(&state->port.mutex);
1409}
1410
1411static void uart_set_termios(struct tty_struct *tty,
1412 struct ktermios *old_termios)
1413{
1414 struct uart_state *state = tty->driver_data;
1415 struct uart_port *uport;
1416 unsigned int cflag = tty->termios.c_cflag;
1417 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1418 bool sw_changed = false;
1419
1420 mutex_lock(&state->port.mutex);
1421 uport = uart_port_check(state);
1422 if (!uport)
1423 goto out;
1424
1425 /*
1426 * Drivers doing software flow control also need to know
1427 * about changes to these input settings.
1428 */
1429 if (uport->flags & UPF_SOFT_FLOW) {
1430 iflag_mask |= IXANY|IXON|IXOFF;
1431 sw_changed =
1432 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1433 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1434 }
1435
1436 /*
1437 * These are the bits that are used to setup various
1438 * flags in the low level driver. We can ignore the Bfoo
1439 * bits in c_cflag; c_[io]speed will always be set
1440 * appropriately by set_termios() in tty_ioctl.c
1441 */
1442 if ((cflag ^ old_termios->c_cflag) == 0 &&
1443 tty->termios.c_ospeed == old_termios->c_ospeed &&
1444 tty->termios.c_ispeed == old_termios->c_ispeed &&
1445 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1446 !sw_changed) {
1447 goto out;
1448 }
1449
1450 uart_change_speed(tty, state, old_termios);
1451 /* reload cflag from termios; port driver may have overriden flags */
1452 cflag = tty->termios.c_cflag;
1453
1454 /* Handle transition to B0 status */
1455 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1456 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1457 /* Handle transition away from B0 status */
1458 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1459 unsigned int mask = TIOCM_DTR;
1460 if (!(cflag & CRTSCTS) || !tty_throttled(tty))
1461 mask |= TIOCM_RTS;
1462 uart_set_mctrl(uport, mask);
1463 }
1464out:
1465 mutex_unlock(&state->port.mutex);
1466}
1467
1468/*
1469 * Calls to uart_close() are serialised via the tty_lock in
1470 * drivers/tty/tty_io.c:tty_release()
1471 * drivers/tty/tty_io.c:do_tty_hangup()
1472 */
1473static void uart_close(struct tty_struct *tty, struct file *filp)
1474{
1475 struct uart_state *state = tty->driver_data;
1476
1477 if (!state) {
1478 struct uart_driver *drv = tty->driver->driver_state;
1479 struct tty_port *port;
1480
1481 state = drv->state + tty->index;
1482 port = &state->port;
1483 spin_lock_irq(&port->lock);
1484 --port->count;
1485 spin_unlock_irq(&port->lock);
1486 return;
1487 }
1488
1489 pr_debug("uart_close(%d) called\n", tty->index);
1490
1491 tty_port_close(tty->port, tty, filp);
1492}
1493
1494static void uart_tty_port_shutdown(struct tty_port *port)
1495{
1496 struct uart_state *state = container_of(port, struct uart_state, port);
1497 struct uart_port *uport = uart_port_check(state);
1498
1499 /*
1500 * At this point, we stop accepting input. To do this, we
1501 * disable the receive line status interrupts.
1502 */
1503 if (WARN(!uport, "detached port still initialized!\n"))
1504 return;
1505
1506 spin_lock_irq(&uport->lock);
1507 uport->ops->stop_rx(uport);
1508 spin_unlock_irq(&uport->lock);
1509
1510 uart_port_shutdown(port);
1511
1512 /*
1513 * It's possible for shutdown to be called after suspend if we get
1514 * a DCD drop (hangup) at just the right time. Clear suspended bit so
1515 * we don't try to resume a port that has been shutdown.
1516 */
1517 tty_port_set_suspended(port, 0);
1518
1519 uart_change_pm(state, UART_PM_STATE_OFF);
1520
1521}
1522
1523static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1524{
1525 struct uart_state *state = tty->driver_data;
1526 struct uart_port *port;
1527 unsigned long char_time, expire;
1528
1529 port = uart_port_ref(state);
1530 if (!port)
1531 return;
1532
1533 if (port->type == PORT_UNKNOWN || port->fifosize == 0) {
1534 uart_port_deref(port);
1535 return;
1536 }
1537
1538 /*
1539 * Set the check interval to be 1/5 of the estimated time to
1540 * send a single character, and make it at least 1. The check
1541 * interval should also be less than the timeout.
1542 *
1543 * Note: we have to use pretty tight timings here to satisfy
1544 * the NIST-PCTS.
1545 */
1546 char_time = (port->timeout - HZ/50) / port->fifosize;
1547 char_time = char_time / 5;
1548 if (char_time == 0)
1549 char_time = 1;
1550 if (timeout && timeout < char_time)
1551 char_time = timeout;
1552
1553 /*
1554 * If the transmitter hasn't cleared in twice the approximate
1555 * amount of time to send the entire FIFO, it probably won't
1556 * ever clear. This assumes the UART isn't doing flow
1557 * control, which is currently the case. Hence, if it ever
1558 * takes longer than port->timeout, this is probably due to a
1559 * UART bug of some kind. So, we clamp the timeout parameter at
1560 * 2*port->timeout.
1561 */
1562 if (timeout == 0 || timeout > 2 * port->timeout)
1563 timeout = 2 * port->timeout;
1564
1565 expire = jiffies + timeout;
1566
1567 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1568 port->line, jiffies, expire);
1569
1570 /*
1571 * Check whether the transmitter is empty every 'char_time'.
1572 * 'timeout' / 'expire' give us the maximum amount of time
1573 * we wait.
1574 */
1575 while (!port->ops->tx_empty(port)) {
1576 msleep_interruptible(jiffies_to_msecs(char_time));
1577 if (signal_pending(current))
1578 break;
1579 if (time_after(jiffies, expire))
1580 break;
1581 }
1582 uart_port_deref(port);
1583}
1584
1585/*
1586 * Calls to uart_hangup() are serialised by the tty_lock in
1587 * drivers/tty/tty_io.c:do_tty_hangup()
1588 * This runs from a workqueue and can sleep for a _short_ time only.
1589 */
1590static void uart_hangup(struct tty_struct *tty)
1591{
1592 struct uart_state *state = tty->driver_data;
1593 struct tty_port *port = &state->port;
1594 struct uart_port *uport;
1595 unsigned long flags;
1596
1597 pr_debug("uart_hangup(%d)\n", tty->index);
1598
1599 mutex_lock(&port->mutex);
1600 uport = uart_port_check(state);
1601 WARN(!uport, "hangup of detached port!\n");
1602
1603 if (tty_port_active(port)) {
1604 uart_flush_buffer(tty);
1605 uart_shutdown(tty, state);
1606 spin_lock_irqsave(&port->lock, flags);
1607 port->count = 0;
1608 spin_unlock_irqrestore(&port->lock, flags);
1609 tty_port_set_active(port, 0);
1610 tty_port_tty_set(port, NULL);
1611 if (uport && !uart_console(uport))
1612 uart_change_pm(state, UART_PM_STATE_OFF);
1613 wake_up_interruptible(&port->open_wait);
1614 wake_up_interruptible(&port->delta_msr_wait);
1615 }
1616 mutex_unlock(&port->mutex);
1617}
1618
1619/* uport == NULL if uart_port has already been removed */
1620static void uart_port_shutdown(struct tty_port *port)
1621{
1622 struct uart_state *state = container_of(port, struct uart_state, port);
1623 struct uart_port *uport = uart_port_check(state);
1624
1625 /*
1626 * clear delta_msr_wait queue to avoid mem leaks: we may free
1627 * the irq here so the queue might never be woken up. Note
1628 * that we won't end up waiting on delta_msr_wait again since
1629 * any outstanding file descriptors should be pointing at
1630 * hung_up_tty_fops now.
1631 */
1632 wake_up_interruptible(&port->delta_msr_wait);
1633
1634 /*
1635 * Free the IRQ and disable the port.
1636 */
1637 if (uport)
1638 uport->ops->shutdown(uport);
1639
1640 /*
1641 * Ensure that the IRQ handler isn't running on another CPU.
1642 */
1643 if (uport)
1644 synchronize_irq(uport->irq);
1645}
1646
1647static int uart_carrier_raised(struct tty_port *port)
1648{
1649 struct uart_state *state = container_of(port, struct uart_state, port);
1650 struct uart_port *uport;
1651 int mctrl;
1652
1653 uport = uart_port_ref(state);
1654 /*
1655 * Should never observe uport == NULL since checks for hangup should
1656 * abort the tty_port_block_til_ready() loop before checking for carrier
1657 * raised -- but report carrier raised if it does anyway so open will
1658 * continue and not sleep
1659 */
1660 if (WARN_ON(!uport))
1661 return 1;
1662 spin_lock_irq(&uport->lock);
1663 uart_enable_ms(uport);
1664 mctrl = uport->ops->get_mctrl(uport);
1665 spin_unlock_irq(&uport->lock);
1666 uart_port_deref(uport);
1667 if (mctrl & TIOCM_CAR)
1668 return 1;
1669 return 0;
1670}
1671
1672static void uart_dtr_rts(struct tty_port *port, int raise)
1673{
1674 struct uart_state *state = container_of(port, struct uart_state, port);
1675 struct uart_port *uport;
1676
1677 uport = uart_port_ref(state);
1678 if (!uport)
1679 return;
1680 uart_port_dtr_rts(uport, raise);
1681 uart_port_deref(uport);
1682}
1683
1684/*
1685 * Calls to uart_open are serialised by the tty_lock in
1686 * drivers/tty/tty_io.c:tty_open()
1687 * Note that if this fails, then uart_close() _will_ be called.
1688 *
1689 * In time, we want to scrap the "opening nonpresent ports"
1690 * behaviour and implement an alternative way for setserial
1691 * to set base addresses/ports/types. This will allow us to
1692 * get rid of a certain amount of extra tests.
1693 */
1694static int uart_open(struct tty_struct *tty, struct file *filp)
1695{
1696 struct uart_driver *drv = tty->driver->driver_state;
1697 int retval, line = tty->index;
1698 struct uart_state *state = drv->state + line;
1699
1700 tty->driver_data = state;
1701
1702 retval = tty_port_open(&state->port, tty, filp);
1703 if (retval > 0)
1704 retval = 0;
1705
1706 return retval;
1707}
1708
1709static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1710{
1711 struct uart_state *state = container_of(port, struct uart_state, port);
1712 struct uart_port *uport;
1713
1714 uport = uart_port_check(state);
1715 if (!uport || uport->flags & UPF_DEAD)
1716 return -ENXIO;
1717
1718 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
1719
1720 /*
1721 * Start up the serial port.
1722 */
1723 return uart_startup(tty, state, 0);
1724}
1725
1726static const char *uart_type(struct uart_port *port)
1727{
1728 const char *str = NULL;
1729
1730 if (port->ops->type)
1731 str = port->ops->type(port);
1732
1733 if (!str)
1734 str = "unknown";
1735
1736 return str;
1737}
1738
1739#ifdef CONFIG_PROC_FS
1740
1741static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1742{
1743 struct uart_state *state = drv->state + i;
1744 struct tty_port *port = &state->port;
1745 enum uart_pm_state pm_state;
1746 struct uart_port *uport;
1747 char stat_buf[32];
1748 unsigned int status;
1749 int mmio;
1750
1751 mutex_lock(&port->mutex);
1752 uport = uart_port_check(state);
1753 if (!uport)
1754 goto out;
1755
1756 mmio = uport->iotype >= UPIO_MEM;
1757 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1758 uport->line, uart_type(uport),
1759 mmio ? "mmio:0x" : "port:",
1760 mmio ? (unsigned long long)uport->mapbase
1761 : (unsigned long long)uport->iobase,
1762 uport->irq);
1763
1764 if (uport->type == PORT_UNKNOWN) {
1765 seq_putc(m, '\n');
1766 goto out;
1767 }
1768
1769 if (capable(CAP_SYS_ADMIN)) {
1770 pm_state = state->pm_state;
1771 if (pm_state != UART_PM_STATE_ON)
1772 uart_change_pm(state, UART_PM_STATE_ON);
1773 spin_lock_irq(&uport->lock);
1774 status = uport->ops->get_mctrl(uport);
1775 spin_unlock_irq(&uport->lock);
1776 if (pm_state != UART_PM_STATE_ON)
1777 uart_change_pm(state, pm_state);
1778
1779 seq_printf(m, " tx:%d rx:%d",
1780 uport->icount.tx, uport->icount.rx);
1781 if (uport->icount.frame)
1782 seq_printf(m, " fe:%d", uport->icount.frame);
1783 if (uport->icount.parity)
1784 seq_printf(m, " pe:%d", uport->icount.parity);
1785 if (uport->icount.brk)
1786 seq_printf(m, " brk:%d", uport->icount.brk);
1787 if (uport->icount.overrun)
1788 seq_printf(m, " oe:%d", uport->icount.overrun);
1789 if (uport->icount.buf_overrun)
1790 seq_printf(m, " bo:%d", uport->icount.buf_overrun);
1791
1792#define INFOBIT(bit, str) \
1793 if (uport->mctrl & (bit)) \
1794 strncat(stat_buf, (str), sizeof(stat_buf) - \
1795 strlen(stat_buf) - 2)
1796#define STATBIT(bit, str) \
1797 if (status & (bit)) \
1798 strncat(stat_buf, (str), sizeof(stat_buf) - \
1799 strlen(stat_buf) - 2)
1800
1801 stat_buf[0] = '\0';
1802 stat_buf[1] = '\0';
1803 INFOBIT(TIOCM_RTS, "|RTS");
1804 STATBIT(TIOCM_CTS, "|CTS");
1805 INFOBIT(TIOCM_DTR, "|DTR");
1806 STATBIT(TIOCM_DSR, "|DSR");
1807 STATBIT(TIOCM_CAR, "|CD");
1808 STATBIT(TIOCM_RNG, "|RI");
1809 if (stat_buf[0])
1810 stat_buf[0] = ' ';
1811
1812 seq_puts(m, stat_buf);
1813 }
1814 seq_putc(m, '\n');
1815#undef STATBIT
1816#undef INFOBIT
1817out:
1818 mutex_unlock(&port->mutex);
1819}
1820
1821static int uart_proc_show(struct seq_file *m, void *v)
1822{
1823 struct tty_driver *ttydrv = m->private;
1824 struct uart_driver *drv = ttydrv->driver_state;
1825 int i;
1826
1827 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
1828 for (i = 0; i < drv->nr; i++)
1829 uart_line_info(m, drv, i);
1830 return 0;
1831}
1832
1833static int uart_proc_open(struct inode *inode, struct file *file)
1834{
1835 return single_open(file, uart_proc_show, PDE_DATA(inode));
1836}
1837
1838static const struct file_operations uart_proc_fops = {
1839 .owner = THIS_MODULE,
1840 .open = uart_proc_open,
1841 .read = seq_read,
1842 .llseek = seq_lseek,
1843 .release = single_release,
1844};
1845#endif
1846
1847#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1848/**
1849 * uart_console_write - write a console message to a serial port
1850 * @port: the port to write the message
1851 * @s: array of characters
1852 * @count: number of characters in string to write
1853 * @putchar: function to write character to port
1854 */
1855void uart_console_write(struct uart_port *port, const char *s,
1856 unsigned int count,
1857 void (*putchar)(struct uart_port *, int))
1858{
1859 unsigned int i;
1860
1861 for (i = 0; i < count; i++, s++) {
1862 if (*s == '\n')
1863 putchar(port, '\r');
1864 putchar(port, *s);
1865 }
1866}
1867EXPORT_SYMBOL_GPL(uart_console_write);
1868
1869/*
1870 * Check whether an invalid uart number has been specified, and
1871 * if so, search for the first available port that does have
1872 * console support.
1873 */
1874struct uart_port * __init
1875uart_get_console(struct uart_port *ports, int nr, struct console *co)
1876{
1877 int idx = co->index;
1878
1879 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1880 ports[idx].membase == NULL))
1881 for (idx = 0; idx < nr; idx++)
1882 if (ports[idx].iobase != 0 ||
1883 ports[idx].membase != NULL)
1884 break;
1885
1886 co->index = idx;
1887
1888 return ports + idx;
1889}
1890
1891/**
1892 * uart_parse_earlycon - Parse earlycon options
1893 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1894 * @iotype: ptr for decoded iotype (out)
1895 * @addr: ptr for decoded mapbase/iobase (out)
1896 * @options: ptr for <options> field; NULL if not present (out)
1897 *
1898 * Decodes earlycon kernel command line parameters of the form
1899 * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1900 * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1901 *
1902 * The optional form
1903 * earlycon=<name>,0x<addr>,<options>
1904 * console=<name>,0x<addr>,<options>
1905 * is also accepted; the returned @iotype will be UPIO_MEM.
1906 *
1907 * Returns 0 on success or -EINVAL on failure
1908 */
1909int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
1910 char **options)
1911{
1912 if (strncmp(p, "mmio,", 5) == 0) {
1913 *iotype = UPIO_MEM;
1914 p += 5;
1915 } else if (strncmp(p, "mmio16,", 7) == 0) {
1916 *iotype = UPIO_MEM16;
1917 p += 7;
1918 } else if (strncmp(p, "mmio32,", 7) == 0) {
1919 *iotype = UPIO_MEM32;
1920 p += 7;
1921 } else if (strncmp(p, "mmio32be,", 9) == 0) {
1922 *iotype = UPIO_MEM32BE;
1923 p += 9;
1924 } else if (strncmp(p, "mmio32native,", 13) == 0) {
1925 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
1926 UPIO_MEM32BE : UPIO_MEM32;
1927 p += 13;
1928 } else if (strncmp(p, "io,", 3) == 0) {
1929 *iotype = UPIO_PORT;
1930 p += 3;
1931 } else if (strncmp(p, "0x", 2) == 0) {
1932 *iotype = UPIO_MEM;
1933 } else {
1934 return -EINVAL;
1935 }
1936
1937 /*
1938 * Before you replace it with kstrtoull(), think about options separator
1939 * (',') it will not tolerate
1940 */
1941 *addr = simple_strtoull(p, NULL, 0);
1942 p = strchr(p, ',');
1943 if (p)
1944 p++;
1945
1946 *options = p;
1947 return 0;
1948}
1949EXPORT_SYMBOL_GPL(uart_parse_earlycon);
1950
1951/**
1952 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1953 * @options: pointer to option string
1954 * @baud: pointer to an 'int' variable for the baud rate.
1955 * @parity: pointer to an 'int' variable for the parity.
1956 * @bits: pointer to an 'int' variable for the number of data bits.
1957 * @flow: pointer to an 'int' variable for the flow control character.
1958 *
1959 * uart_parse_options decodes a string containing the serial console
1960 * options. The format of the string is <baud><parity><bits><flow>,
1961 * eg: 115200n8r
1962 */
1963void
1964uart_parse_options(const char *options, int *baud, int *parity,
1965 int *bits, int *flow)
1966{
1967 const char *s = options;
1968
1969 *baud = simple_strtoul(s, NULL, 10);
1970 while (*s >= '0' && *s <= '9')
1971 s++;
1972 if (*s)
1973 *parity = *s++;
1974 if (*s)
1975 *bits = *s++ - '0';
1976 if (*s)
1977 *flow = *s;
1978}
1979EXPORT_SYMBOL_GPL(uart_parse_options);
1980
1981/**
1982 * uart_set_options - setup the serial console parameters
1983 * @port: pointer to the serial ports uart_port structure
1984 * @co: console pointer
1985 * @baud: baud rate
1986 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1987 * @bits: number of data bits
1988 * @flow: flow control character - 'r' (rts)
1989 */
1990int
1991uart_set_options(struct uart_port *port, struct console *co,
1992 int baud, int parity, int bits, int flow)
1993{
1994 struct ktermios termios;
1995 static struct ktermios dummy;
1996
1997 /*
1998 * Ensure that the serial console lock is initialised
1999 * early.
2000 * If this port is a console, then the spinlock is already
2001 * initialised.
2002 */
2003 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
2004 spin_lock_init(&port->lock);
2005 lockdep_set_class(&port->lock, &port_lock_key);
2006 }
2007
2008 memset(&termios, 0, sizeof(struct ktermios));
2009
2010 termios.c_cflag |= CREAD | HUPCL | CLOCAL;
2011 tty_termios_encode_baud_rate(&termios, baud, baud);
2012
2013 if (bits == 7)
2014 termios.c_cflag |= CS7;
2015 else
2016 termios.c_cflag |= CS8;
2017
2018 switch (parity) {
2019 case 'o': case 'O':
2020 termios.c_cflag |= PARODD;
2021 /*fall through*/
2022 case 'e': case 'E':
2023 termios.c_cflag |= PARENB;
2024 break;
2025 }
2026
2027 if (flow == 'r')
2028 termios.c_cflag |= CRTSCTS;
2029
2030 /*
2031 * some uarts on other side don't support no flow control.
2032 * So we set * DTR in host uart to make them happy
2033 */
2034 port->mctrl |= TIOCM_DTR;
2035
2036 port->ops->set_termios(port, &termios, &dummy);
2037 /*
2038 * Allow the setting of the UART parameters with a NULL console
2039 * too:
2040 */
2041 if (co)
2042 co->cflag = termios.c_cflag;
2043
2044 return 0;
2045}
2046EXPORT_SYMBOL_GPL(uart_set_options);
2047#endif /* CONFIG_SERIAL_CORE_CONSOLE */
2048
2049/**
2050 * uart_change_pm - set power state of the port
2051 *
2052 * @state: port descriptor
2053 * @pm_state: new state
2054 *
2055 * Locking: port->mutex has to be held
2056 */
2057static void uart_change_pm(struct uart_state *state,
2058 enum uart_pm_state pm_state)
2059{
2060 struct uart_port *port = uart_port_check(state);
2061
2062 if (state->pm_state != pm_state) {
2063 if (port && port->ops->pm)
2064 port->ops->pm(port, pm_state, state->pm_state);
2065 state->pm_state = pm_state;
2066 }
2067}
2068
2069struct uart_match {
2070 struct uart_port *port;
2071 struct uart_driver *driver;
2072};
2073
2074static int serial_match_port(struct device *dev, void *data)
2075{
2076 struct uart_match *match = data;
2077 struct tty_driver *tty_drv = match->driver->tty_driver;
2078 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
2079 match->port->line;
2080
2081 return dev->devt == devt; /* Actually, only one tty per port */
2082}
2083
2084int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
2085{
2086 struct uart_state *state = drv->state + uport->line;
2087 struct tty_port *port = &state->port;
2088 struct device *tty_dev;
2089 struct uart_match match = {uport, drv};
2090
2091 mutex_lock(&port->mutex);
2092
2093 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2094 if (tty_dev && device_may_wakeup(tty_dev)) {
2095 enable_irq_wake(uport->irq);
2096 put_device(tty_dev);
2097 mutex_unlock(&port->mutex);
2098 return 0;
2099 }
2100 put_device(tty_dev);
2101
2102 /* Nothing to do if the console is not suspending */
2103 if (!console_suspend_enabled && uart_console(uport))
2104 goto unlock;
2105
2106 uport->suspended = 1;
2107
2108 if (tty_port_initialized(port)) {
2109 const struct uart_ops *ops = uport->ops;
2110 int tries;
2111
2112 tty_port_set_suspended(port, 1);
2113 tty_port_set_initialized(port, 0);
2114
2115 spin_lock_irq(&uport->lock);
2116 ops->stop_tx(uport);
2117 ops->set_mctrl(uport, 0);
2118 ops->stop_rx(uport);
2119 spin_unlock_irq(&uport->lock);
2120
2121 /*
2122 * Wait for the transmitter to empty.
2123 */
2124 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2125 msleep(10);
2126 if (!tries)
2127 dev_err(uport->dev, "%s: Unable to drain transmitter\n",
2128 uport->name);
2129
2130 ops->shutdown(uport);
2131 }
2132
2133 /*
2134 * Disable the console device before suspending.
2135 */
2136 if (uart_console(uport))
2137 console_stop(uport->cons);
2138
2139 uart_change_pm(state, UART_PM_STATE_OFF);
2140unlock:
2141 mutex_unlock(&port->mutex);
2142
2143 return 0;
2144}
2145
2146int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2147{
2148 struct uart_state *state = drv->state + uport->line;
2149 struct tty_port *port = &state->port;
2150 struct device *tty_dev;
2151 struct uart_match match = {uport, drv};
2152 struct ktermios termios;
2153
2154 mutex_lock(&port->mutex);
2155
2156 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2157 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2158 if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq))))
2159 disable_irq_wake(uport->irq);
2160 put_device(tty_dev);
2161 mutex_unlock(&port->mutex);
2162 return 0;
2163 }
2164 put_device(tty_dev);
2165 uport->suspended = 0;
2166
2167 /*
2168 * Re-enable the console device after suspending.
2169 */
2170 if (uart_console(uport)) {
2171 /*
2172 * First try to use the console cflag setting.
2173 */
2174 memset(&termios, 0, sizeof(struct ktermios));
2175 termios.c_cflag = uport->cons->cflag;
2176
2177 /*
2178 * If that's unset, use the tty termios setting.
2179 */
2180 if (port->tty && termios.c_cflag == 0)
2181 termios = port->tty->termios;
2182
2183 if (console_suspend_enabled)
2184 uart_change_pm(state, UART_PM_STATE_ON);
2185 uport->ops->set_termios(uport, &termios, NULL);
2186 if (console_suspend_enabled)
2187 console_start(uport->cons);
2188 }
2189
2190 if (tty_port_suspended(port)) {
2191 const struct uart_ops *ops = uport->ops;
2192 int ret;
2193
2194 uart_change_pm(state, UART_PM_STATE_ON);
2195 spin_lock_irq(&uport->lock);
2196 ops->set_mctrl(uport, 0);
2197 spin_unlock_irq(&uport->lock);
2198 if (console_suspend_enabled || !uart_console(uport)) {
2199 /* Protected by port mutex for now */
2200 struct tty_struct *tty = port->tty;
2201 ret = ops->startup(uport);
2202 if (ret == 0) {
2203 if (tty)
2204 uart_change_speed(tty, state, NULL);
2205 spin_lock_irq(&uport->lock);
2206 ops->set_mctrl(uport, uport->mctrl);
2207 ops->start_tx(uport);
2208 spin_unlock_irq(&uport->lock);
2209 tty_port_set_initialized(port, 1);
2210 } else {
2211 /*
2212 * Failed to resume - maybe hardware went away?
2213 * Clear the "initialized" flag so we won't try
2214 * to call the low level drivers shutdown method.
2215 */
2216 uart_shutdown(tty, state);
2217 }
2218 }
2219
2220 tty_port_set_suspended(port, 0);
2221 }
2222
2223 mutex_unlock(&port->mutex);
2224
2225 return 0;
2226}
2227
2228static inline void
2229uart_report_port(struct uart_driver *drv, struct uart_port *port)
2230{
2231 char address[64];
2232
2233 switch (port->iotype) {
2234 case UPIO_PORT:
2235 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2236 break;
2237 case UPIO_HUB6:
2238 snprintf(address, sizeof(address),
2239 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2240 break;
2241 case UPIO_MEM:
2242 case UPIO_MEM16:
2243 case UPIO_MEM32:
2244 case UPIO_MEM32BE:
2245 case UPIO_AU:
2246 case UPIO_TSI:
2247 snprintf(address, sizeof(address),
2248 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2249 break;
2250 default:
2251 strlcpy(address, "*unknown*", sizeof(address));
2252 break;
2253 }
2254
2255 pr_info("%s%s%s at %s (irq = %d, base_baud = %d) is a %s\n",
2256 port->dev ? dev_name(port->dev) : "",
2257 port->dev ? ": " : "",
2258 port->name,
2259 address, port->irq, port->uartclk / 16, uart_type(port));
2260}
2261
2262static void
2263uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2264 struct uart_port *port)
2265{
2266 unsigned int flags;
2267
2268 /*
2269 * If there isn't a port here, don't do anything further.
2270 */
2271 if (!port->iobase && !port->mapbase && !port->membase)
2272 return;
2273
2274 /*
2275 * Now do the auto configuration stuff. Note that config_port
2276 * is expected to claim the resources and map the port for us.
2277 */
2278 flags = 0;
2279 if (port->flags & UPF_AUTO_IRQ)
2280 flags |= UART_CONFIG_IRQ;
2281 if (port->flags & UPF_BOOT_AUTOCONF) {
2282 if (!(port->flags & UPF_FIXED_TYPE)) {
2283 port->type = PORT_UNKNOWN;
2284 flags |= UART_CONFIG_TYPE;
2285 }
2286 port->ops->config_port(port, flags);
2287 }
2288
2289 if (port->type != PORT_UNKNOWN) {
2290 unsigned long flags;
2291
2292 uart_report_port(drv, port);
2293
2294 /* Power up port for set_mctrl() */
2295 uart_change_pm(state, UART_PM_STATE_ON);
2296
2297 /*
2298 * Ensure that the modem control lines are de-activated.
2299 * keep the DTR setting that is set in uart_set_options()
2300 * We probably don't need a spinlock around this, but
2301 */
2302 spin_lock_irqsave(&port->lock, flags);
2303 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2304 spin_unlock_irqrestore(&port->lock, flags);
2305
2306 /*
2307 * If this driver supports console, and it hasn't been
2308 * successfully registered yet, try to re-register it.
2309 * It may be that the port was not available.
2310 */
2311 if (port->cons && !(port->cons->flags & CON_ENABLED))
2312 register_console(port->cons);
2313
2314 /*
2315 * Power down all ports by default, except the
2316 * console if we have one.
2317 */
2318 if (!uart_console(port))
2319 uart_change_pm(state, UART_PM_STATE_OFF);
2320 }
2321}
2322
2323#ifdef CONFIG_CONSOLE_POLL
2324
2325static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2326{
2327 struct uart_driver *drv = driver->driver_state;
2328 struct uart_state *state = drv->state + line;
2329 struct tty_port *tport;
2330 struct uart_port *port;
2331 int baud = 9600;
2332 int bits = 8;
2333 int parity = 'n';
2334 int flow = 'n';
2335 int ret = 0;
2336
2337 tport = &state->port;
2338 mutex_lock(&tport->mutex);
2339
2340 port = uart_port_check(state);
2341 if (!port || !(port->ops->poll_get_char && port->ops->poll_put_char)) {
2342 ret = -1;
2343 goto out;
2344 }
2345
2346 if (port->ops->poll_init) {
2347 /*
2348 * We don't set initialized as we only initialized the hw,
2349 * e.g. state->xmit is still uninitialized.
2350 */
2351 if (!tty_port_initialized(tport))
2352 ret = port->ops->poll_init(port);
2353 }
2354
2355 if (!ret && options) {
2356 uart_parse_options(options, &baud, &parity, &bits, &flow);
2357 ret = uart_set_options(port, NULL, baud, parity, bits, flow);
2358 }
2359out:
2360 mutex_unlock(&tport->mutex);
2361 return ret;
2362}
2363
2364static int uart_poll_get_char(struct tty_driver *driver, int line)
2365{
2366 struct uart_driver *drv = driver->driver_state;
2367 struct uart_state *state = drv->state + line;
2368 struct uart_port *port;
2369 int ret = -1;
2370
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 port = uart_port_ref(state);
2387 if (!port)
2388 return;
2389
2390 if (ch == '\n')
2391 port->ops->poll_put_char(port, '\r');
2392 port->ops->poll_put_char(port, ch);
2393 uart_port_deref(port);
2394}
2395#endif
2396
2397static const struct tty_operations uart_ops = {
2398 .open = uart_open,
2399 .close = uart_close,
2400 .write = uart_write,
2401 .put_char = uart_put_char,
2402 .flush_chars = uart_flush_chars,
2403 .write_room = uart_write_room,
2404 .chars_in_buffer= uart_chars_in_buffer,
2405 .flush_buffer = uart_flush_buffer,
2406 .ioctl = uart_ioctl,
2407 .throttle = uart_throttle,
2408 .unthrottle = uart_unthrottle,
2409 .send_xchar = uart_send_xchar,
2410 .set_termios = uart_set_termios,
2411 .set_ldisc = uart_set_ldisc,
2412 .stop = uart_stop,
2413 .start = uart_start,
2414 .hangup = uart_hangup,
2415 .break_ctl = uart_break_ctl,
2416 .wait_until_sent= uart_wait_until_sent,
2417#ifdef CONFIG_PROC_FS
2418 .proc_fops = &uart_proc_fops,
2419#endif
2420 .tiocmget = uart_tiocmget,
2421 .tiocmset = uart_tiocmset,
2422 .get_icount = uart_get_icount,
2423#ifdef CONFIG_CONSOLE_POLL
2424 .poll_init = uart_poll_init,
2425 .poll_get_char = uart_poll_get_char,
2426 .poll_put_char = uart_poll_put_char,
2427#endif
2428};
2429
2430static const struct tty_port_operations uart_port_ops = {
2431 .carrier_raised = uart_carrier_raised,
2432 .dtr_rts = uart_dtr_rts,
2433 .activate = uart_port_activate,
2434 .shutdown = uart_tty_port_shutdown,
2435};
2436
2437/**
2438 * uart_register_driver - register a driver with the uart core layer
2439 * @drv: low level driver structure
2440 *
2441 * Register a uart driver with the core driver. We in turn register
2442 * with the tty layer, and initialise the core driver per-port state.
2443 *
2444 * We have a proc file in /proc/tty/driver which is named after the
2445 * normal driver.
2446 *
2447 * drv->port should be NULL, and the per-port structures should be
2448 * registered using uart_add_one_port after this call has succeeded.
2449 */
2450int uart_register_driver(struct uart_driver *drv)
2451{
2452 struct tty_driver *normal;
2453 int i, retval;
2454
2455 BUG_ON(drv->state);
2456
2457 /*
2458 * Maybe we should be using a slab cache for this, especially if
2459 * we have a large number of ports to handle.
2460 */
2461 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2462 if (!drv->state)
2463 goto out;
2464
2465 normal = alloc_tty_driver(drv->nr);
2466 if (!normal)
2467 goto out_kfree;
2468
2469 drv->tty_driver = normal;
2470
2471 normal->driver_name = drv->driver_name;
2472 normal->name = drv->dev_name;
2473 normal->major = drv->major;
2474 normal->minor_start = drv->minor;
2475 normal->type = TTY_DRIVER_TYPE_SERIAL;
2476 normal->subtype = SERIAL_TYPE_NORMAL;
2477 normal->init_termios = tty_std_termios;
2478 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2479 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2480 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2481 normal->driver_state = drv;
2482 tty_set_operations(normal, &uart_ops);
2483
2484 /*
2485 * Initialise the UART state(s).
2486 */
2487 for (i = 0; i < drv->nr; i++) {
2488 struct uart_state *state = drv->state + i;
2489 struct tty_port *port = &state->port;
2490
2491 tty_port_init(port);
2492 port->ops = &uart_port_ops;
2493 }
2494
2495 retval = tty_register_driver(normal);
2496 if (retval >= 0)
2497 return retval;
2498
2499 for (i = 0; i < drv->nr; i++)
2500 tty_port_destroy(&drv->state[i].port);
2501 put_tty_driver(normal);
2502out_kfree:
2503 kfree(drv->state);
2504out:
2505 return -ENOMEM;
2506}
2507
2508/**
2509 * uart_unregister_driver - remove a driver from the uart core layer
2510 * @drv: low level driver structure
2511 *
2512 * Remove all references to a driver from the core driver. The low
2513 * level driver must have removed all its ports via the
2514 * uart_remove_one_port() if it registered them with uart_add_one_port().
2515 * (ie, drv->port == NULL)
2516 */
2517void uart_unregister_driver(struct uart_driver *drv)
2518{
2519 struct tty_driver *p = drv->tty_driver;
2520 unsigned int i;
2521
2522 tty_unregister_driver(p);
2523 put_tty_driver(p);
2524 for (i = 0; i < drv->nr; i++)
2525 tty_port_destroy(&drv->state[i].port);
2526 kfree(drv->state);
2527 drv->state = NULL;
2528 drv->tty_driver = NULL;
2529}
2530
2531struct tty_driver *uart_console_device(struct console *co, int *index)
2532{
2533 struct uart_driver *p = co->data;
2534 *index = co->index;
2535 return p->tty_driver;
2536}
2537
2538static ssize_t uart_get_attr_uartclk(struct device *dev,
2539 struct device_attribute *attr, char *buf)
2540{
2541 struct serial_struct tmp;
2542 struct tty_port *port = dev_get_drvdata(dev);
2543
2544 uart_get_info(port, &tmp);
2545 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2546}
2547
2548static ssize_t uart_get_attr_type(struct device *dev,
2549 struct device_attribute *attr, char *buf)
2550{
2551 struct serial_struct tmp;
2552 struct tty_port *port = dev_get_drvdata(dev);
2553
2554 uart_get_info(port, &tmp);
2555 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2556}
2557static ssize_t uart_get_attr_line(struct device *dev,
2558 struct device_attribute *attr, char *buf)
2559{
2560 struct serial_struct tmp;
2561 struct tty_port *port = dev_get_drvdata(dev);
2562
2563 uart_get_info(port, &tmp);
2564 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2565}
2566
2567static ssize_t uart_get_attr_port(struct device *dev,
2568 struct device_attribute *attr, char *buf)
2569{
2570 struct serial_struct tmp;
2571 struct tty_port *port = dev_get_drvdata(dev);
2572 unsigned long ioaddr;
2573
2574 uart_get_info(port, &tmp);
2575 ioaddr = tmp.port;
2576 if (HIGH_BITS_OFFSET)
2577 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2578 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2579}
2580
2581static ssize_t uart_get_attr_irq(struct device *dev,
2582 struct device_attribute *attr, char *buf)
2583{
2584 struct serial_struct tmp;
2585 struct tty_port *port = dev_get_drvdata(dev);
2586
2587 uart_get_info(port, &tmp);
2588 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2589}
2590
2591static ssize_t uart_get_attr_flags(struct device *dev,
2592 struct device_attribute *attr, char *buf)
2593{
2594 struct serial_struct tmp;
2595 struct tty_port *port = dev_get_drvdata(dev);
2596
2597 uart_get_info(port, &tmp);
2598 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2599}
2600
2601static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2602 struct device_attribute *attr, char *buf)
2603{
2604 struct serial_struct tmp;
2605 struct tty_port *port = dev_get_drvdata(dev);
2606
2607 uart_get_info(port, &tmp);
2608 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2609}
2610
2611
2612static ssize_t uart_get_attr_close_delay(struct device *dev,
2613 struct device_attribute *attr, char *buf)
2614{
2615 struct serial_struct tmp;
2616 struct tty_port *port = dev_get_drvdata(dev);
2617
2618 uart_get_info(port, &tmp);
2619 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2620}
2621
2622
2623static ssize_t uart_get_attr_closing_wait(struct device *dev,
2624 struct device_attribute *attr, char *buf)
2625{
2626 struct serial_struct tmp;
2627 struct tty_port *port = dev_get_drvdata(dev);
2628
2629 uart_get_info(port, &tmp);
2630 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2631}
2632
2633static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2634 struct device_attribute *attr, char *buf)
2635{
2636 struct serial_struct tmp;
2637 struct tty_port *port = dev_get_drvdata(dev);
2638
2639 uart_get_info(port, &tmp);
2640 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2641}
2642
2643static ssize_t uart_get_attr_io_type(struct device *dev,
2644 struct device_attribute *attr, char *buf)
2645{
2646 struct serial_struct tmp;
2647 struct tty_port *port = dev_get_drvdata(dev);
2648
2649 uart_get_info(port, &tmp);
2650 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2651}
2652
2653static ssize_t uart_get_attr_iomem_base(struct device *dev,
2654 struct device_attribute *attr, char *buf)
2655{
2656 struct serial_struct tmp;
2657 struct tty_port *port = dev_get_drvdata(dev);
2658
2659 uart_get_info(port, &tmp);
2660 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2661}
2662
2663static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2664 struct device_attribute *attr, char *buf)
2665{
2666 struct serial_struct tmp;
2667 struct tty_port *port = dev_get_drvdata(dev);
2668
2669 uart_get_info(port, &tmp);
2670 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2671}
2672
2673static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2674static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2675static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2676static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2677static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2678static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2679static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2680static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2681static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2682static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2683static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2684static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2685static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2686
2687static struct attribute *tty_dev_attrs[] = {
2688 &dev_attr_type.attr,
2689 &dev_attr_line.attr,
2690 &dev_attr_port.attr,
2691 &dev_attr_irq.attr,
2692 &dev_attr_flags.attr,
2693 &dev_attr_xmit_fifo_size.attr,
2694 &dev_attr_uartclk.attr,
2695 &dev_attr_close_delay.attr,
2696 &dev_attr_closing_wait.attr,
2697 &dev_attr_custom_divisor.attr,
2698 &dev_attr_io_type.attr,
2699 &dev_attr_iomem_base.attr,
2700 &dev_attr_iomem_reg_shift.attr,
2701 NULL,
2702 };
2703
2704static const struct attribute_group tty_dev_attr_group = {
2705 .attrs = tty_dev_attrs,
2706 };
2707
2708/**
2709 * uart_add_one_port - attach a driver-defined port structure
2710 * @drv: pointer to the uart low level driver structure for this port
2711 * @uport: uart port structure to use for this port.
2712 *
2713 * This allows the driver to register its own uart_port structure
2714 * with the core driver. The main purpose is to allow the low
2715 * level uart drivers to expand uart_port, rather than having yet
2716 * more levels of structures.
2717 */
2718int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2719{
2720 struct uart_state *state;
2721 struct tty_port *port;
2722 int ret = 0;
2723 struct device *tty_dev;
2724 int num_groups;
2725
2726 BUG_ON(in_interrupt());
2727
2728 if (uport->line >= drv->nr)
2729 return -EINVAL;
2730
2731 state = drv->state + uport->line;
2732 port = &state->port;
2733
2734 mutex_lock(&port_mutex);
2735 mutex_lock(&port->mutex);
2736 if (state->uart_port) {
2737 ret = -EINVAL;
2738 goto out;
2739 }
2740
2741 /* Link the port to the driver state table and vice versa */
2742 atomic_set(&state->refcount, 1);
2743 init_waitqueue_head(&state->remove_wait);
2744 state->uart_port = uport;
2745 uport->state = state;
2746
2747 state->pm_state = UART_PM_STATE_UNDEFINED;
2748 uport->cons = drv->cons;
2749 uport->minor = drv->tty_driver->minor_start + uport->line;
2750 uport->name = kasprintf(GFP_KERNEL, "%s%d", drv->dev_name,
2751 drv->tty_driver->name_base + uport->line);
2752 if (!uport->name) {
2753 ret = -ENOMEM;
2754 goto out;
2755 }
2756
2757 /*
2758 * If this port is a console, then the spinlock is already
2759 * initialised.
2760 */
2761 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2762 spin_lock_init(&uport->lock);
2763 lockdep_set_class(&uport->lock, &port_lock_key);
2764 }
2765 if (uport->cons && uport->dev)
2766 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2767
2768 uart_configure_port(drv, state, uport);
2769
2770 port->console = uart_console(uport);
2771
2772 num_groups = 2;
2773 if (uport->attr_group)
2774 num_groups++;
2775
2776 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2777 GFP_KERNEL);
2778 if (!uport->tty_groups) {
2779 ret = -ENOMEM;
2780 goto out;
2781 }
2782 uport->tty_groups[0] = &tty_dev_attr_group;
2783 if (uport->attr_group)
2784 uport->tty_groups[1] = uport->attr_group;
2785
2786 /*
2787 * Register the port whether it's detected or not. This allows
2788 * setserial to be used to alter this port's parameters.
2789 */
2790 tty_dev = tty_port_register_device_attr_serdev(port, drv->tty_driver,
2791 uport->line, uport->dev, port, uport->tty_groups);
2792 if (likely(!IS_ERR(tty_dev))) {
2793 device_set_wakeup_capable(tty_dev, 1);
2794 } else {
2795 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2796 uport->line);
2797 }
2798
2799 /*
2800 * Ensure UPF_DEAD is not set.
2801 */
2802 uport->flags &= ~UPF_DEAD;
2803
2804 out:
2805 mutex_unlock(&port->mutex);
2806 mutex_unlock(&port_mutex);
2807
2808 return ret;
2809}
2810
2811/**
2812 * uart_remove_one_port - detach a driver defined port structure
2813 * @drv: pointer to the uart low level driver structure for this port
2814 * @uport: uart port structure for this port
2815 *
2816 * This unhooks (and hangs up) the specified port structure from the
2817 * core driver. No further calls will be made to the low-level code
2818 * for this port.
2819 */
2820int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2821{
2822 struct uart_state *state = drv->state + uport->line;
2823 struct tty_port *port = &state->port;
2824 struct uart_port *uart_port;
2825 struct tty_struct *tty;
2826 int ret = 0;
2827
2828 BUG_ON(in_interrupt());
2829
2830 mutex_lock(&port_mutex);
2831
2832 /*
2833 * Mark the port "dead" - this prevents any opens from
2834 * succeeding while we shut down the port.
2835 */
2836 mutex_lock(&port->mutex);
2837 uart_port = uart_port_check(state);
2838 if (uart_port != uport)
2839 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2840 uart_port, uport);
2841
2842 if (!uart_port) {
2843 mutex_unlock(&port->mutex);
2844 ret = -EINVAL;
2845 goto out;
2846 }
2847 uport->flags |= UPF_DEAD;
2848 mutex_unlock(&port->mutex);
2849
2850 /*
2851 * Remove the devices from the tty layer
2852 */
2853 tty_port_unregister_device(port, drv->tty_driver, uport->line);
2854
2855 tty = tty_port_tty_get(port);
2856 if (tty) {
2857 tty_vhangup(port->tty);
2858 tty_kref_put(tty);
2859 }
2860
2861 /*
2862 * If the port is used as a console, unregister it
2863 */
2864 if (uart_console(uport))
2865 unregister_console(uport->cons);
2866
2867 /*
2868 * Free the port IO and memory resources, if any.
2869 */
2870 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
2871 uport->ops->release_port(uport);
2872 kfree(uport->tty_groups);
2873 kfree(uport->name);
2874
2875 /*
2876 * Indicate that there isn't a port here anymore.
2877 */
2878 uport->type = PORT_UNKNOWN;
2879
2880 mutex_lock(&port->mutex);
2881 WARN_ON(atomic_dec_return(&state->refcount) < 0);
2882 wait_event(state->remove_wait, !atomic_read(&state->refcount));
2883 state->uart_port = NULL;
2884 mutex_unlock(&port->mutex);
2885out:
2886 mutex_unlock(&port_mutex);
2887
2888 return ret;
2889}
2890
2891/*
2892 * Are the two ports equivalent?
2893 */
2894int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2895{
2896 if (port1->iotype != port2->iotype)
2897 return 0;
2898
2899 switch (port1->iotype) {
2900 case UPIO_PORT:
2901 return (port1->iobase == port2->iobase);
2902 case UPIO_HUB6:
2903 return (port1->iobase == port2->iobase) &&
2904 (port1->hub6 == port2->hub6);
2905 case UPIO_MEM:
2906 case UPIO_MEM16:
2907 case UPIO_MEM32:
2908 case UPIO_MEM32BE:
2909 case UPIO_AU:
2910 case UPIO_TSI:
2911 return (port1->mapbase == port2->mapbase);
2912 }
2913 return 0;
2914}
2915EXPORT_SYMBOL(uart_match_port);
2916
2917/**
2918 * uart_handle_dcd_change - handle a change of carrier detect state
2919 * @uport: uart_port structure for the open port
2920 * @status: new carrier detect status, nonzero if active
2921 *
2922 * Caller must hold uport->lock
2923 */
2924void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2925{
2926 struct tty_port *port = &uport->state->port;
2927 struct tty_struct *tty = port->tty;
2928 struct tty_ldisc *ld;
2929
2930 lockdep_assert_held_once(&uport->lock);
2931
2932 if (tty) {
2933 ld = tty_ldisc_ref(tty);
2934 if (ld) {
2935 if (ld->ops->dcd_change)
2936 ld->ops->dcd_change(tty, status);
2937 tty_ldisc_deref(ld);
2938 }
2939 }
2940
2941 uport->icount.dcd++;
2942
2943 if (uart_dcd_enabled(uport)) {
2944 if (status)
2945 wake_up_interruptible(&port->open_wait);
2946 else if (tty)
2947 tty_hangup(tty);
2948 }
2949}
2950EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2951
2952/**
2953 * uart_handle_cts_change - handle a change of clear-to-send state
2954 * @uport: uart_port structure for the open port
2955 * @status: new clear to send status, nonzero if active
2956 *
2957 * Caller must hold uport->lock
2958 */
2959void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2960{
2961 lockdep_assert_held_once(&uport->lock);
2962
2963 uport->icount.cts++;
2964
2965 if (uart_softcts_mode(uport)) {
2966 if (uport->hw_stopped) {
2967 if (status) {
2968 uport->hw_stopped = 0;
2969 uport->ops->start_tx(uport);
2970 uart_write_wakeup(uport);
2971 }
2972 } else {
2973 if (!status) {
2974 uport->hw_stopped = 1;
2975 uport->ops->stop_tx(uport);
2976 }
2977 }
2978
2979 }
2980}
2981EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2982
2983/**
2984 * uart_insert_char - push a char to the uart layer
2985 *
2986 * User is responsible to call tty_flip_buffer_push when they are done with
2987 * insertion.
2988 *
2989 * @port: corresponding port
2990 * @status: state of the serial port RX buffer (LSR for 8250)
2991 * @overrun: mask of overrun bits in @status
2992 * @ch: character to push
2993 * @flag: flag for the character (see TTY_NORMAL and friends)
2994 */
2995void uart_insert_char(struct uart_port *port, unsigned int status,
2996 unsigned int overrun, unsigned int ch, unsigned int flag)
2997{
2998 struct tty_port *tport = &port->state->port;
2999
3000 if ((status & port->ignore_status_mask & ~overrun) == 0)
3001 if (tty_insert_flip_char(tport, ch, flag) == 0)
3002 ++port->icount.buf_overrun;
3003
3004 /*
3005 * Overrun is special. Since it's reported immediately,
3006 * it doesn't affect the current character.
3007 */
3008 if (status & ~port->ignore_status_mask & overrun)
3009 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
3010 ++port->icount.buf_overrun;
3011}
3012EXPORT_SYMBOL_GPL(uart_insert_char);
3013
3014EXPORT_SYMBOL(uart_write_wakeup);
3015EXPORT_SYMBOL(uart_register_driver);
3016EXPORT_SYMBOL(uart_unregister_driver);
3017EXPORT_SYMBOL(uart_suspend_port);
3018EXPORT_SYMBOL(uart_resume_port);
3019EXPORT_SYMBOL(uart_add_one_port);
3020EXPORT_SYMBOL(uart_remove_one_port);
3021
3022/**
3023 * uart_get_rs485_mode() - retrieve rs485 properties for given uart
3024 * @dev: uart device
3025 * @rs485conf: output parameter
3026 *
3027 * This function implements the device tree binding described in
3028 * Documentation/devicetree/bindings/serial/rs485.txt.
3029 */
3030void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf)
3031{
3032 u32 rs485_delay[2];
3033 int ret;
3034
3035 ret = device_property_read_u32_array(dev, "rs485-rts-delay",
3036 rs485_delay, 2);
3037 if (!ret) {
3038 rs485conf->delay_rts_before_send = rs485_delay[0];
3039 rs485conf->delay_rts_after_send = rs485_delay[1];
3040 } else {
3041 rs485conf->delay_rts_before_send = 0;
3042 rs485conf->delay_rts_after_send = 0;
3043 }
3044
3045 /*
3046 * Clear full-duplex and enabled flags, set RTS polarity to active high
3047 * to get to a defined state with the following properties:
3048 */
3049 rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED |
3050 SER_RS485_RTS_AFTER_SEND);
3051 rs485conf->flags |= SER_RS485_RTS_ON_SEND;
3052
3053 if (device_property_read_bool(dev, "rs485-rx-during-tx"))
3054 rs485conf->flags |= SER_RS485_RX_DURING_TX;
3055
3056 if (device_property_read_bool(dev, "linux,rs485-enabled-at-boot-time"))
3057 rs485conf->flags |= SER_RS485_ENABLED;
3058
3059 if (device_property_read_bool(dev, "rs485-rts-active-low")) {
3060 rs485conf->flags &= ~SER_RS485_RTS_ON_SEND;
3061 rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
3062 }
3063}
3064EXPORT_SYMBOL_GPL(uart_get_rs485_mode);
3065
3066MODULE_DESCRIPTION("Serial driver core");
3067MODULE_LICENSE("GPL");