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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#include <linux/security.h>
26
27#include <linux/irq.h>
28#include <linux/uaccess.h>
29
30/*
31 * This is used to lock changes in serial line configuration.
32 */
33static DEFINE_MUTEX(port_mutex);
34
35/*
36 * lockdep: port->lock is initialized in two places, but we
37 * want only one lock-class:
38 */
39static struct lock_class_key port_lock_key;
40
41#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
42
43static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
44 struct ktermios *old_termios);
45static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
46static void uart_change_pm(struct uart_state *state,
47 enum uart_pm_state pm_state);
48
49static void uart_port_shutdown(struct tty_port *port);
50
51static int uart_dcd_enabled(struct uart_port *uport)
52{
53 return !!(uport->status & UPSTAT_DCD_ENABLE);
54}
55
56static inline struct uart_port *uart_port_ref(struct uart_state *state)
57{
58 if (atomic_add_unless(&state->refcount, 1, 0))
59 return state->uart_port;
60 return NULL;
61}
62
63static inline void uart_port_deref(struct uart_port *uport)
64{
65 if (atomic_dec_and_test(&uport->state->refcount))
66 wake_up(&uport->state->remove_wait);
67}
68
69#define uart_port_lock(state, flags) \
70 ({ \
71 struct uart_port *__uport = uart_port_ref(state); \
72 if (__uport) \
73 spin_lock_irqsave(&__uport->lock, flags); \
74 __uport; \
75 })
76
77#define uart_port_unlock(uport, flags) \
78 ({ \
79 struct uart_port *__uport = uport; \
80 if (__uport) { \
81 spin_unlock_irqrestore(&__uport->lock, flags); \
82 uart_port_deref(__uport); \
83 } \
84 })
85
86static inline struct uart_port *uart_port_check(struct uart_state *state)
87{
88 lockdep_assert_held(&state->port.mutex);
89 return state->uart_port;
90}
91
92/*
93 * This routine is used by the interrupt handler to schedule processing in
94 * the software interrupt portion of the driver.
95 */
96void uart_write_wakeup(struct uart_port *port)
97{
98 struct uart_state *state = port->state;
99 /*
100 * This means you called this function _after_ the port was
101 * closed. No cookie for you.
102 */
103 BUG_ON(!state);
104 tty_port_tty_wakeup(&state->port);
105}
106
107static void uart_stop(struct tty_struct *tty)
108{
109 struct uart_state *state = tty->driver_data;
110 struct uart_port *port;
111 unsigned long flags;
112
113 port = uart_port_lock(state, flags);
114 if (port)
115 port->ops->stop_tx(port);
116 uart_port_unlock(port, flags);
117}
118
119static void __uart_start(struct tty_struct *tty)
120{
121 struct uart_state *state = tty->driver_data;
122 struct uart_port *port = state->uart_port;
123
124 if (port && !uart_tx_stopped(port))
125 port->ops->start_tx(port);
126}
127
128static void uart_start(struct tty_struct *tty)
129{
130 struct uart_state *state = tty->driver_data;
131 struct uart_port *port;
132 unsigned long flags;
133
134 port = uart_port_lock(state, flags);
135 __uart_start(tty);
136 uart_port_unlock(port, flags);
137}
138
139static void
140uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
141{
142 unsigned long flags;
143 unsigned int old;
144
145 spin_lock_irqsave(&port->lock, flags);
146 old = port->mctrl;
147 port->mctrl = (old & ~clear) | set;
148 if (old != port->mctrl)
149 port->ops->set_mctrl(port, port->mctrl);
150 spin_unlock_irqrestore(&port->lock, flags);
151}
152
153#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
154#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
155
156static void uart_port_dtr_rts(struct uart_port *uport, int raise)
157{
158 int rs485_on = uport->rs485_config &&
159 (uport->rs485.flags & SER_RS485_ENABLED);
160 int RTS_after_send = !!(uport->rs485.flags & SER_RS485_RTS_AFTER_SEND);
161
162 if (raise) {
163 if (rs485_on && !RTS_after_send) {
164 uart_set_mctrl(uport, TIOCM_DTR);
165 uart_clear_mctrl(uport, TIOCM_RTS);
166 } else {
167 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
168 }
169 } else {
170 unsigned int clear = TIOCM_DTR;
171
172 clear |= (!rs485_on || !RTS_after_send) ? TIOCM_RTS : 0;
173 uart_clear_mctrl(uport, clear);
174 }
175}
176
177/*
178 * Startup the port. This will be called once per open. All calls
179 * will be serialised by the per-port mutex.
180 */
181static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
182 int init_hw)
183{
184 struct uart_port *uport = uart_port_check(state);
185 unsigned long page;
186 unsigned long flags = 0;
187 int retval = 0;
188
189 if (uport->type == PORT_UNKNOWN)
190 return 1;
191
192 /*
193 * Make sure the device is in D0 state.
194 */
195 uart_change_pm(state, UART_PM_STATE_ON);
196
197 /*
198 * Initialise and allocate the transmit and temporary
199 * buffer.
200 */
201 page = get_zeroed_page(GFP_KERNEL);
202 if (!page)
203 return -ENOMEM;
204
205 uart_port_lock(state, flags);
206 if (!state->xmit.buf) {
207 state->xmit.buf = (unsigned char *) page;
208 uart_circ_clear(&state->xmit);
209 uart_port_unlock(uport, flags);
210 } else {
211 uart_port_unlock(uport, flags);
212 /*
213 * Do not free() the page under the port lock, see
214 * uart_shutdown().
215 */
216 free_page(page);
217 }
218
219 retval = uport->ops->startup(uport);
220 if (retval == 0) {
221 if (uart_console(uport) && uport->cons->cflag) {
222 tty->termios.c_cflag = uport->cons->cflag;
223 uport->cons->cflag = 0;
224 }
225 /*
226 * Initialise the hardware port settings.
227 */
228 uart_change_speed(tty, state, NULL);
229
230 /*
231 * Setup the RTS and DTR signals once the
232 * port is open and ready to respond.
233 */
234 if (init_hw && C_BAUD(tty))
235 uart_port_dtr_rts(uport, 1);
236 }
237
238 /*
239 * This is to allow setserial on this port. People may want to set
240 * port/irq/type and then reconfigure the port properly if it failed
241 * now.
242 */
243 if (retval && capable(CAP_SYS_ADMIN))
244 return 1;
245
246 return retval;
247}
248
249static int uart_startup(struct tty_struct *tty, struct uart_state *state,
250 int init_hw)
251{
252 struct tty_port *port = &state->port;
253 int retval;
254
255 if (tty_port_initialized(port))
256 return 0;
257
258 retval = uart_port_startup(tty, state, init_hw);
259 if (retval)
260 set_bit(TTY_IO_ERROR, &tty->flags);
261
262 return retval;
263}
264
265/*
266 * This routine will shutdown a serial port; interrupts are disabled, and
267 * DTR is dropped if the hangup on close termio flag is on. Calls to
268 * uart_shutdown are serialised by the per-port semaphore.
269 *
270 * uport == NULL if uart_port has already been removed
271 */
272static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
273{
274 struct uart_port *uport = uart_port_check(state);
275 struct tty_port *port = &state->port;
276 unsigned long flags = 0;
277 char *xmit_buf = NULL;
278
279 /*
280 * Set the TTY IO error marker
281 */
282 if (tty)
283 set_bit(TTY_IO_ERROR, &tty->flags);
284
285 if (tty_port_initialized(port)) {
286 tty_port_set_initialized(port, 0);
287
288 /*
289 * Turn off DTR and RTS early.
290 */
291 if (uport && uart_console(uport) && tty)
292 uport->cons->cflag = tty->termios.c_cflag;
293
294 if (!tty || C_HUPCL(tty))
295 uart_port_dtr_rts(uport, 0);
296
297 uart_port_shutdown(port);
298 }
299
300 /*
301 * It's possible for shutdown to be called after suspend if we get
302 * a DCD drop (hangup) at just the right time. Clear suspended bit so
303 * we don't try to resume a port that has been shutdown.
304 */
305 tty_port_set_suspended(port, 0);
306
307 /*
308 * Do not free() the transmit buffer page under the port lock since
309 * this can create various circular locking scenarios. For instance,
310 * console driver may need to allocate/free a debug object, which
311 * can endup in printk() recursion.
312 */
313 uart_port_lock(state, flags);
314 xmit_buf = state->xmit.buf;
315 state->xmit.buf = NULL;
316 uart_port_unlock(uport, flags);
317
318 if (xmit_buf)
319 free_page((unsigned long)xmit_buf);
320}
321
322/**
323 * uart_update_timeout - update per-port FIFO timeout.
324 * @port: uart_port structure describing the port
325 * @cflag: termios cflag value
326 * @baud: speed of the port
327 *
328 * Set the port FIFO timeout value. The @cflag value should
329 * reflect the actual hardware settings.
330 */
331void
332uart_update_timeout(struct uart_port *port, unsigned int cflag,
333 unsigned int baud)
334{
335 unsigned int bits;
336
337 /* byte size and parity */
338 switch (cflag & CSIZE) {
339 case CS5:
340 bits = 7;
341 break;
342 case CS6:
343 bits = 8;
344 break;
345 case CS7:
346 bits = 9;
347 break;
348 default:
349 bits = 10;
350 break; /* CS8 */
351 }
352
353 if (cflag & CSTOPB)
354 bits++;
355 if (cflag & PARENB)
356 bits++;
357
358 /*
359 * The total number of bits to be transmitted in the fifo.
360 */
361 bits = bits * port->fifosize;
362
363 /*
364 * Figure the timeout to send the above number of bits.
365 * Add .02 seconds of slop
366 */
367 port->timeout = (HZ * bits) / baud + HZ/50;
368}
369
370EXPORT_SYMBOL(uart_update_timeout);
371
372/**
373 * uart_get_baud_rate - return baud rate for a particular port
374 * @port: uart_port structure describing the port in question.
375 * @termios: desired termios settings.
376 * @old: old termios (or NULL)
377 * @min: minimum acceptable baud rate
378 * @max: maximum acceptable baud rate
379 *
380 * Decode the termios structure into a numeric baud rate,
381 * taking account of the magic 38400 baud rate (with spd_*
382 * flags), and mapping the %B0 rate to 9600 baud.
383 *
384 * If the new baud rate is invalid, try the old termios setting.
385 * If it's still invalid, we try 9600 baud.
386 *
387 * Update the @termios structure to reflect the baud rate
388 * we're actually going to be using. Don't do this for the case
389 * where B0 is requested ("hang up").
390 */
391unsigned int
392uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
393 struct ktermios *old, unsigned int min, unsigned int max)
394{
395 unsigned int try;
396 unsigned int baud;
397 unsigned int altbaud;
398 int hung_up = 0;
399 upf_t flags = port->flags & UPF_SPD_MASK;
400
401 switch (flags) {
402 case UPF_SPD_HI:
403 altbaud = 57600;
404 break;
405 case UPF_SPD_VHI:
406 altbaud = 115200;
407 break;
408 case UPF_SPD_SHI:
409 altbaud = 230400;
410 break;
411 case UPF_SPD_WARP:
412 altbaud = 460800;
413 break;
414 default:
415 altbaud = 38400;
416 break;
417 }
418
419 for (try = 0; try < 2; try++) {
420 baud = tty_termios_baud_rate(termios);
421
422 /*
423 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
424 * Die! Die! Die!
425 */
426 if (try == 0 && baud == 38400)
427 baud = altbaud;
428
429 /*
430 * Special case: B0 rate.
431 */
432 if (baud == 0) {
433 hung_up = 1;
434 baud = 9600;
435 }
436
437 if (baud >= min && baud <= max)
438 return baud;
439
440 /*
441 * Oops, the quotient was zero. Try again with
442 * the old baud rate if possible.
443 */
444 termios->c_cflag &= ~CBAUD;
445 if (old) {
446 baud = tty_termios_baud_rate(old);
447 if (!hung_up)
448 tty_termios_encode_baud_rate(termios,
449 baud, baud);
450 old = NULL;
451 continue;
452 }
453
454 /*
455 * As a last resort, if the range cannot be met then clip to
456 * the nearest chip supported rate.
457 */
458 if (!hung_up) {
459 if (baud <= min)
460 tty_termios_encode_baud_rate(termios,
461 min + 1, min + 1);
462 else
463 tty_termios_encode_baud_rate(termios,
464 max - 1, max - 1);
465 }
466 }
467 /* Should never happen */
468 WARN_ON(1);
469 return 0;
470}
471
472EXPORT_SYMBOL(uart_get_baud_rate);
473
474/**
475 * uart_get_divisor - return uart clock divisor
476 * @port: uart_port structure describing the port.
477 * @baud: desired baud rate
478 *
479 * Calculate the uart clock divisor for the port.
480 */
481unsigned int
482uart_get_divisor(struct uart_port *port, unsigned int baud)
483{
484 unsigned int quot;
485
486 /*
487 * Old custom speed handling.
488 */
489 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
490 quot = port->custom_divisor;
491 else
492 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
493
494 return quot;
495}
496
497EXPORT_SYMBOL(uart_get_divisor);
498
499/* Caller holds port mutex */
500static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
501 struct ktermios *old_termios)
502{
503 struct uart_port *uport = uart_port_check(state);
504 struct ktermios *termios;
505 int hw_stopped;
506
507 /*
508 * If we have no tty, termios, or the port does not exist,
509 * then we can't set the parameters for this port.
510 */
511 if (!tty || uport->type == PORT_UNKNOWN)
512 return;
513
514 termios = &tty->termios;
515 uport->ops->set_termios(uport, termios, old_termios);
516
517 /*
518 * Set modem status enables based on termios cflag
519 */
520 spin_lock_irq(&uport->lock);
521 if (termios->c_cflag & CRTSCTS)
522 uport->status |= UPSTAT_CTS_ENABLE;
523 else
524 uport->status &= ~UPSTAT_CTS_ENABLE;
525
526 if (termios->c_cflag & CLOCAL)
527 uport->status &= ~UPSTAT_DCD_ENABLE;
528 else
529 uport->status |= UPSTAT_DCD_ENABLE;
530
531 /* reset sw-assisted CTS flow control based on (possibly) new mode */
532 hw_stopped = uport->hw_stopped;
533 uport->hw_stopped = uart_softcts_mode(uport) &&
534 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
535 if (uport->hw_stopped) {
536 if (!hw_stopped)
537 uport->ops->stop_tx(uport);
538 } else {
539 if (hw_stopped)
540 __uart_start(tty);
541 }
542 spin_unlock_irq(&uport->lock);
543}
544
545static int uart_put_char(struct tty_struct *tty, unsigned char c)
546{
547 struct uart_state *state = tty->driver_data;
548 struct uart_port *port;
549 struct circ_buf *circ;
550 unsigned long flags;
551 int ret = 0;
552
553 circ = &state->xmit;
554 port = uart_port_lock(state, flags);
555 if (!circ->buf) {
556 uart_port_unlock(port, flags);
557 return 0;
558 }
559
560 if (port && uart_circ_chars_free(circ) != 0) {
561 circ->buf[circ->head] = c;
562 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
563 ret = 1;
564 }
565 uart_port_unlock(port, flags);
566 return ret;
567}
568
569static void uart_flush_chars(struct tty_struct *tty)
570{
571 uart_start(tty);
572}
573
574static int uart_write(struct tty_struct *tty,
575 const unsigned char *buf, int count)
576{
577 struct uart_state *state = tty->driver_data;
578 struct uart_port *port;
579 struct circ_buf *circ;
580 unsigned long flags;
581 int c, ret = 0;
582
583 /*
584 * This means you called this function _after_ the port was
585 * closed. No cookie for you.
586 */
587 if (!state) {
588 WARN_ON(1);
589 return -EL3HLT;
590 }
591
592 port = uart_port_lock(state, flags);
593 circ = &state->xmit;
594 if (!circ->buf) {
595 uart_port_unlock(port, flags);
596 return 0;
597 }
598
599 while (port) {
600 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
601 if (count < c)
602 c = count;
603 if (c <= 0)
604 break;
605 memcpy(circ->buf + circ->head, buf, c);
606 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
607 buf += c;
608 count -= c;
609 ret += c;
610 }
611
612 __uart_start(tty);
613 uart_port_unlock(port, flags);
614 return ret;
615}
616
617static int uart_write_room(struct tty_struct *tty)
618{
619 struct uart_state *state = tty->driver_data;
620 struct uart_port *port;
621 unsigned long flags;
622 int ret;
623
624 port = uart_port_lock(state, flags);
625 ret = uart_circ_chars_free(&state->xmit);
626 uart_port_unlock(port, flags);
627 return ret;
628}
629
630static int uart_chars_in_buffer(struct tty_struct *tty)
631{
632 struct uart_state *state = tty->driver_data;
633 struct uart_port *port;
634 unsigned long flags;
635 int ret;
636
637 port = uart_port_lock(state, flags);
638 ret = uart_circ_chars_pending(&state->xmit);
639 uart_port_unlock(port, flags);
640 return ret;
641}
642
643static void uart_flush_buffer(struct tty_struct *tty)
644{
645 struct uart_state *state = tty->driver_data;
646 struct uart_port *port;
647 unsigned long flags;
648
649 /*
650 * This means you called this function _after_ the port was
651 * closed. No cookie for you.
652 */
653 if (!state) {
654 WARN_ON(1);
655 return;
656 }
657
658 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
659
660 port = uart_port_lock(state, flags);
661 if (!port)
662 return;
663 uart_circ_clear(&state->xmit);
664 if (port->ops->flush_buffer)
665 port->ops->flush_buffer(port);
666 uart_port_unlock(port, flags);
667 tty_port_tty_wakeup(&state->port);
668}
669
670/*
671 * This function is used to send a high-priority XON/XOFF character to
672 * the device
673 */
674static void uart_send_xchar(struct tty_struct *tty, char ch)
675{
676 struct uart_state *state = tty->driver_data;
677 struct uart_port *port;
678 unsigned long flags;
679
680 port = uart_port_ref(state);
681 if (!port)
682 return;
683
684 if (port->ops->send_xchar)
685 port->ops->send_xchar(port, ch);
686 else {
687 spin_lock_irqsave(&port->lock, flags);
688 port->x_char = ch;
689 if (ch)
690 port->ops->start_tx(port);
691 spin_unlock_irqrestore(&port->lock, flags);
692 }
693 uart_port_deref(port);
694}
695
696static void uart_throttle(struct tty_struct *tty)
697{
698 struct uart_state *state = tty->driver_data;
699 upstat_t mask = UPSTAT_SYNC_FIFO;
700 struct uart_port *port;
701
702 port = uart_port_ref(state);
703 if (!port)
704 return;
705
706 if (I_IXOFF(tty))
707 mask |= UPSTAT_AUTOXOFF;
708 if (C_CRTSCTS(tty))
709 mask |= UPSTAT_AUTORTS;
710
711 if (port->status & mask) {
712 port->ops->throttle(port);
713 mask &= ~port->status;
714 }
715
716 if (mask & UPSTAT_AUTORTS)
717 uart_clear_mctrl(port, TIOCM_RTS);
718
719 if (mask & UPSTAT_AUTOXOFF)
720 uart_send_xchar(tty, STOP_CHAR(tty));
721
722 uart_port_deref(port);
723}
724
725static void uart_unthrottle(struct tty_struct *tty)
726{
727 struct uart_state *state = tty->driver_data;
728 upstat_t mask = UPSTAT_SYNC_FIFO;
729 struct uart_port *port;
730
731 port = uart_port_ref(state);
732 if (!port)
733 return;
734
735 if (I_IXOFF(tty))
736 mask |= UPSTAT_AUTOXOFF;
737 if (C_CRTSCTS(tty))
738 mask |= UPSTAT_AUTORTS;
739
740 if (port->status & mask) {
741 port->ops->unthrottle(port);
742 mask &= ~port->status;
743 }
744
745 if (mask & UPSTAT_AUTORTS)
746 uart_set_mctrl(port, TIOCM_RTS);
747
748 if (mask & UPSTAT_AUTOXOFF)
749 uart_send_xchar(tty, START_CHAR(tty));
750
751 uart_port_deref(port);
752}
753
754static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
755{
756 struct uart_state *state = container_of(port, struct uart_state, port);
757 struct uart_port *uport;
758 int ret = -ENODEV;
759
760 memset(retinfo, 0, sizeof(*retinfo));
761
762 /*
763 * Ensure the state we copy is consistent and no hardware changes
764 * occur as we go
765 */
766 mutex_lock(&port->mutex);
767 uport = uart_port_check(state);
768 if (!uport)
769 goto out;
770
771 retinfo->type = uport->type;
772 retinfo->line = uport->line;
773 retinfo->port = uport->iobase;
774 if (HIGH_BITS_OFFSET)
775 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
776 retinfo->irq = uport->irq;
777 retinfo->flags = (__force int)uport->flags;
778 retinfo->xmit_fifo_size = uport->fifosize;
779 retinfo->baud_base = uport->uartclk / 16;
780 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
781 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
782 ASYNC_CLOSING_WAIT_NONE :
783 jiffies_to_msecs(port->closing_wait) / 10;
784 retinfo->custom_divisor = uport->custom_divisor;
785 retinfo->hub6 = uport->hub6;
786 retinfo->io_type = uport->iotype;
787 retinfo->iomem_reg_shift = uport->regshift;
788 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
789
790 ret = 0;
791out:
792 mutex_unlock(&port->mutex);
793 return ret;
794}
795
796static int uart_get_info_user(struct tty_struct *tty,
797 struct serial_struct *ss)
798{
799 struct uart_state *state = tty->driver_data;
800 struct tty_port *port = &state->port;
801
802 return uart_get_info(port, ss) < 0 ? -EIO : 0;
803}
804
805static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
806 struct uart_state *state,
807 struct serial_struct *new_info)
808{
809 struct uart_port *uport = uart_port_check(state);
810 unsigned long new_port;
811 unsigned int change_irq, change_port, closing_wait;
812 unsigned int old_custom_divisor, close_delay;
813 upf_t old_flags, new_flags;
814 int retval = 0;
815
816 if (!uport)
817 return -EIO;
818
819 new_port = new_info->port;
820 if (HIGH_BITS_OFFSET)
821 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
822
823 new_info->irq = irq_canonicalize(new_info->irq);
824 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
825 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
826 ASYNC_CLOSING_WAIT_NONE :
827 msecs_to_jiffies(new_info->closing_wait * 10);
828
829
830 change_irq = !(uport->flags & UPF_FIXED_PORT)
831 && new_info->irq != uport->irq;
832
833 /*
834 * Since changing the 'type' of the port changes its resource
835 * allocations, we should treat type changes the same as
836 * IO port changes.
837 */
838 change_port = !(uport->flags & UPF_FIXED_PORT)
839 && (new_port != uport->iobase ||
840 (unsigned long)new_info->iomem_base != uport->mapbase ||
841 new_info->hub6 != uport->hub6 ||
842 new_info->io_type != uport->iotype ||
843 new_info->iomem_reg_shift != uport->regshift ||
844 new_info->type != uport->type);
845
846 old_flags = uport->flags;
847 new_flags = (__force upf_t)new_info->flags;
848 old_custom_divisor = uport->custom_divisor;
849
850 if (!capable(CAP_SYS_ADMIN)) {
851 retval = -EPERM;
852 if (change_irq || change_port ||
853 (new_info->baud_base != uport->uartclk / 16) ||
854 (close_delay != port->close_delay) ||
855 (closing_wait != port->closing_wait) ||
856 (new_info->xmit_fifo_size &&
857 new_info->xmit_fifo_size != uport->fifosize) ||
858 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
859 goto exit;
860 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
861 (new_flags & UPF_USR_MASK));
862 uport->custom_divisor = new_info->custom_divisor;
863 goto check_and_exit;
864 }
865
866 retval = security_locked_down(LOCKDOWN_TIOCSSERIAL);
867 if (retval && (change_irq || change_port))
868 goto exit;
869
870 /*
871 * Ask the low level driver to verify the settings.
872 */
873 if (uport->ops->verify_port)
874 retval = uport->ops->verify_port(uport, new_info);
875
876 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
877 (new_info->baud_base < 9600))
878 retval = -EINVAL;
879
880 if (retval)
881 goto exit;
882
883 if (change_port || change_irq) {
884 retval = -EBUSY;
885
886 /*
887 * Make sure that we are the sole user of this port.
888 */
889 if (tty_port_users(port) > 1)
890 goto exit;
891
892 /*
893 * We need to shutdown the serial port at the old
894 * port/type/irq combination.
895 */
896 uart_shutdown(tty, state);
897 }
898
899 if (change_port) {
900 unsigned long old_iobase, old_mapbase;
901 unsigned int old_type, old_iotype, old_hub6, old_shift;
902
903 old_iobase = uport->iobase;
904 old_mapbase = uport->mapbase;
905 old_type = uport->type;
906 old_hub6 = uport->hub6;
907 old_iotype = uport->iotype;
908 old_shift = uport->regshift;
909
910 /*
911 * Free and release old regions
912 */
913 if (old_type != PORT_UNKNOWN && uport->ops->release_port)
914 uport->ops->release_port(uport);
915
916 uport->iobase = new_port;
917 uport->type = new_info->type;
918 uport->hub6 = new_info->hub6;
919 uport->iotype = new_info->io_type;
920 uport->regshift = new_info->iomem_reg_shift;
921 uport->mapbase = (unsigned long)new_info->iomem_base;
922
923 /*
924 * Claim and map the new regions
925 */
926 if (uport->type != PORT_UNKNOWN && uport->ops->request_port) {
927 retval = uport->ops->request_port(uport);
928 } else {
929 /* Always success - Jean II */
930 retval = 0;
931 }
932
933 /*
934 * If we fail to request resources for the
935 * new port, try to restore the old settings.
936 */
937 if (retval) {
938 uport->iobase = old_iobase;
939 uport->type = old_type;
940 uport->hub6 = old_hub6;
941 uport->iotype = old_iotype;
942 uport->regshift = old_shift;
943 uport->mapbase = old_mapbase;
944
945 if (old_type != PORT_UNKNOWN) {
946 retval = uport->ops->request_port(uport);
947 /*
948 * If we failed to restore the old settings,
949 * we fail like this.
950 */
951 if (retval)
952 uport->type = PORT_UNKNOWN;
953
954 /*
955 * We failed anyway.
956 */
957 retval = -EBUSY;
958 }
959
960 /* Added to return the correct error -Ram Gupta */
961 goto exit;
962 }
963 }
964
965 if (change_irq)
966 uport->irq = new_info->irq;
967 if (!(uport->flags & UPF_FIXED_PORT))
968 uport->uartclk = new_info->baud_base * 16;
969 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
970 (new_flags & UPF_CHANGE_MASK);
971 uport->custom_divisor = new_info->custom_divisor;
972 port->close_delay = close_delay;
973 port->closing_wait = closing_wait;
974 if (new_info->xmit_fifo_size)
975 uport->fifosize = new_info->xmit_fifo_size;
976 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
977
978 check_and_exit:
979 retval = 0;
980 if (uport->type == PORT_UNKNOWN)
981 goto exit;
982 if (tty_port_initialized(port)) {
983 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
984 old_custom_divisor != uport->custom_divisor) {
985 /*
986 * If they're setting up a custom divisor or speed,
987 * instead of clearing it, then bitch about it.
988 */
989 if (uport->flags & UPF_SPD_MASK) {
990 dev_notice_ratelimited(uport->dev,
991 "%s sets custom speed on %s. This is deprecated.\n",
992 current->comm,
993 tty_name(port->tty));
994 }
995 uart_change_speed(tty, state, NULL);
996 }
997 } else {
998 retval = uart_startup(tty, state, 1);
999 if (retval == 0)
1000 tty_port_set_initialized(port, true);
1001 if (retval > 0)
1002 retval = 0;
1003 }
1004 exit:
1005 return retval;
1006}
1007
1008static int uart_set_info_user(struct tty_struct *tty, struct serial_struct *ss)
1009{
1010 struct uart_state *state = tty->driver_data;
1011 struct tty_port *port = &state->port;
1012 int retval;
1013
1014 down_write(&tty->termios_rwsem);
1015 /*
1016 * This semaphore protects port->count. It is also
1017 * very useful to prevent opens. Also, take the
1018 * port configuration semaphore to make sure that a
1019 * module insertion/removal doesn't change anything
1020 * under us.
1021 */
1022 mutex_lock(&port->mutex);
1023 retval = uart_set_info(tty, port, state, ss);
1024 mutex_unlock(&port->mutex);
1025 up_write(&tty->termios_rwsem);
1026 return retval;
1027}
1028
1029/**
1030 * uart_get_lsr_info - get line status register info
1031 * @tty: tty associated with the UART
1032 * @state: UART being queried
1033 * @value: returned modem value
1034 */
1035static int uart_get_lsr_info(struct tty_struct *tty,
1036 struct uart_state *state, unsigned int __user *value)
1037{
1038 struct uart_port *uport = uart_port_check(state);
1039 unsigned int result;
1040
1041 result = uport->ops->tx_empty(uport);
1042
1043 /*
1044 * If we're about to load something into the transmit
1045 * register, we'll pretend the transmitter isn't empty to
1046 * avoid a race condition (depending on when the transmit
1047 * interrupt happens).
1048 */
1049 if (uport->x_char ||
1050 ((uart_circ_chars_pending(&state->xmit) > 0) &&
1051 !uart_tx_stopped(uport)))
1052 result &= ~TIOCSER_TEMT;
1053
1054 return put_user(result, value);
1055}
1056
1057static int uart_tiocmget(struct tty_struct *tty)
1058{
1059 struct uart_state *state = tty->driver_data;
1060 struct tty_port *port = &state->port;
1061 struct uart_port *uport;
1062 int result = -EIO;
1063
1064 mutex_lock(&port->mutex);
1065 uport = uart_port_check(state);
1066 if (!uport)
1067 goto out;
1068
1069 if (!tty_io_error(tty)) {
1070 result = uport->mctrl;
1071 spin_lock_irq(&uport->lock);
1072 result |= uport->ops->get_mctrl(uport);
1073 spin_unlock_irq(&uport->lock);
1074 }
1075out:
1076 mutex_unlock(&port->mutex);
1077 return result;
1078}
1079
1080static int
1081uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
1082{
1083 struct uart_state *state = tty->driver_data;
1084 struct tty_port *port = &state->port;
1085 struct uart_port *uport;
1086 int ret = -EIO;
1087
1088 mutex_lock(&port->mutex);
1089 uport = uart_port_check(state);
1090 if (!uport)
1091 goto out;
1092
1093 if (!tty_io_error(tty)) {
1094 uart_update_mctrl(uport, set, clear);
1095 ret = 0;
1096 }
1097out:
1098 mutex_unlock(&port->mutex);
1099 return ret;
1100}
1101
1102static int uart_break_ctl(struct tty_struct *tty, int break_state)
1103{
1104 struct uart_state *state = tty->driver_data;
1105 struct tty_port *port = &state->port;
1106 struct uart_port *uport;
1107 int ret = -EIO;
1108
1109 mutex_lock(&port->mutex);
1110 uport = uart_port_check(state);
1111 if (!uport)
1112 goto out;
1113
1114 if (uport->type != PORT_UNKNOWN)
1115 uport->ops->break_ctl(uport, break_state);
1116 ret = 0;
1117out:
1118 mutex_unlock(&port->mutex);
1119 return ret;
1120}
1121
1122static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1123{
1124 struct tty_port *port = &state->port;
1125 struct uart_port *uport;
1126 int flags, ret;
1127
1128 if (!capable(CAP_SYS_ADMIN))
1129 return -EPERM;
1130
1131 /*
1132 * Take the per-port semaphore. This prevents count from
1133 * changing, and hence any extra opens of the port while
1134 * we're auto-configuring.
1135 */
1136 if (mutex_lock_interruptible(&port->mutex))
1137 return -ERESTARTSYS;
1138
1139 uport = uart_port_check(state);
1140 if (!uport) {
1141 ret = -EIO;
1142 goto out;
1143 }
1144
1145 ret = -EBUSY;
1146 if (tty_port_users(port) == 1) {
1147 uart_shutdown(tty, state);
1148
1149 /*
1150 * If we already have a port type configured,
1151 * we must release its resources.
1152 */
1153 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
1154 uport->ops->release_port(uport);
1155
1156 flags = UART_CONFIG_TYPE;
1157 if (uport->flags & UPF_AUTO_IRQ)
1158 flags |= UART_CONFIG_IRQ;
1159
1160 /*
1161 * This will claim the ports resources if
1162 * a port is found.
1163 */
1164 uport->ops->config_port(uport, flags);
1165
1166 ret = uart_startup(tty, state, 1);
1167 if (ret == 0)
1168 tty_port_set_initialized(port, true);
1169 if (ret > 0)
1170 ret = 0;
1171 }
1172out:
1173 mutex_unlock(&port->mutex);
1174 return ret;
1175}
1176
1177static void uart_enable_ms(struct uart_port *uport)
1178{
1179 /*
1180 * Force modem status interrupts on
1181 */
1182 if (uport->ops->enable_ms)
1183 uport->ops->enable_ms(uport);
1184}
1185
1186/*
1187 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1188 * - mask passed in arg for lines of interest
1189 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1190 * Caller should use TIOCGICOUNT to see which one it was
1191 *
1192 * FIXME: This wants extracting into a common all driver implementation
1193 * of TIOCMWAIT using tty_port.
1194 */
1195static int uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1196{
1197 struct uart_port *uport;
1198 struct tty_port *port = &state->port;
1199 DECLARE_WAITQUEUE(wait, current);
1200 struct uart_icount cprev, cnow;
1201 int ret;
1202
1203 /*
1204 * note the counters on entry
1205 */
1206 uport = uart_port_ref(state);
1207 if (!uport)
1208 return -EIO;
1209 spin_lock_irq(&uport->lock);
1210 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1211 uart_enable_ms(uport);
1212 spin_unlock_irq(&uport->lock);
1213
1214 add_wait_queue(&port->delta_msr_wait, &wait);
1215 for (;;) {
1216 spin_lock_irq(&uport->lock);
1217 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1218 spin_unlock_irq(&uport->lock);
1219
1220 set_current_state(TASK_INTERRUPTIBLE);
1221
1222 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1223 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1224 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1225 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1226 ret = 0;
1227 break;
1228 }
1229
1230 schedule();
1231
1232 /* see if a signal did it */
1233 if (signal_pending(current)) {
1234 ret = -ERESTARTSYS;
1235 break;
1236 }
1237
1238 cprev = cnow;
1239 }
1240 __set_current_state(TASK_RUNNING);
1241 remove_wait_queue(&port->delta_msr_wait, &wait);
1242 uart_port_deref(uport);
1243
1244 return ret;
1245}
1246
1247/*
1248 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1249 * Return: write counters to the user passed counter struct
1250 * NB: both 1->0 and 0->1 transitions are counted except for
1251 * RI where only 0->1 is counted.
1252 */
1253static int uart_get_icount(struct tty_struct *tty,
1254 struct serial_icounter_struct *icount)
1255{
1256 struct uart_state *state = tty->driver_data;
1257 struct uart_icount cnow;
1258 struct uart_port *uport;
1259
1260 uport = uart_port_ref(state);
1261 if (!uport)
1262 return -EIO;
1263 spin_lock_irq(&uport->lock);
1264 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1265 spin_unlock_irq(&uport->lock);
1266 uart_port_deref(uport);
1267
1268 icount->cts = cnow.cts;
1269 icount->dsr = cnow.dsr;
1270 icount->rng = cnow.rng;
1271 icount->dcd = cnow.dcd;
1272 icount->rx = cnow.rx;
1273 icount->tx = cnow.tx;
1274 icount->frame = cnow.frame;
1275 icount->overrun = cnow.overrun;
1276 icount->parity = cnow.parity;
1277 icount->brk = cnow.brk;
1278 icount->buf_overrun = cnow.buf_overrun;
1279
1280 return 0;
1281}
1282
1283static int uart_get_rs485_config(struct uart_port *port,
1284 struct serial_rs485 __user *rs485)
1285{
1286 unsigned long flags;
1287 struct serial_rs485 aux;
1288
1289 spin_lock_irqsave(&port->lock, flags);
1290 aux = port->rs485;
1291 spin_unlock_irqrestore(&port->lock, flags);
1292
1293 if (copy_to_user(rs485, &aux, sizeof(aux)))
1294 return -EFAULT;
1295
1296 return 0;
1297}
1298
1299static int uart_set_rs485_config(struct uart_port *port,
1300 struct serial_rs485 __user *rs485_user)
1301{
1302 struct serial_rs485 rs485;
1303 int ret;
1304 unsigned long flags;
1305
1306 if (!port->rs485_config)
1307 return -ENOIOCTLCMD;
1308
1309 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1310 return -EFAULT;
1311
1312 spin_lock_irqsave(&port->lock, flags);
1313 ret = port->rs485_config(port, &rs485);
1314 spin_unlock_irqrestore(&port->lock, flags);
1315 if (ret)
1316 return ret;
1317
1318 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1319 return -EFAULT;
1320
1321 return 0;
1322}
1323
1324static int uart_get_iso7816_config(struct uart_port *port,
1325 struct serial_iso7816 __user *iso7816)
1326{
1327 unsigned long flags;
1328 struct serial_iso7816 aux;
1329
1330 if (!port->iso7816_config)
1331 return -ENOIOCTLCMD;
1332
1333 spin_lock_irqsave(&port->lock, flags);
1334 aux = port->iso7816;
1335 spin_unlock_irqrestore(&port->lock, flags);
1336
1337 if (copy_to_user(iso7816, &aux, sizeof(aux)))
1338 return -EFAULT;
1339
1340 return 0;
1341}
1342
1343static int uart_set_iso7816_config(struct uart_port *port,
1344 struct serial_iso7816 __user *iso7816_user)
1345{
1346 struct serial_iso7816 iso7816;
1347 int i, ret;
1348 unsigned long flags;
1349
1350 if (!port->iso7816_config)
1351 return -ENOIOCTLCMD;
1352
1353 if (copy_from_user(&iso7816, iso7816_user, sizeof(*iso7816_user)))
1354 return -EFAULT;
1355
1356 /*
1357 * There are 5 words reserved for future use. Check that userspace
1358 * doesn't put stuff in there to prevent breakages in the future.
1359 */
1360 for (i = 0; i < 5; i++)
1361 if (iso7816.reserved[i])
1362 return -EINVAL;
1363
1364 spin_lock_irqsave(&port->lock, flags);
1365 ret = port->iso7816_config(port, &iso7816);
1366 spin_unlock_irqrestore(&port->lock, flags);
1367 if (ret)
1368 return ret;
1369
1370 if (copy_to_user(iso7816_user, &port->iso7816, sizeof(port->iso7816)))
1371 return -EFAULT;
1372
1373 return 0;
1374}
1375
1376/*
1377 * Called via sys_ioctl. We can use spin_lock_irq() here.
1378 */
1379static int
1380uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
1381{
1382 struct uart_state *state = tty->driver_data;
1383 struct tty_port *port = &state->port;
1384 struct uart_port *uport;
1385 void __user *uarg = (void __user *)arg;
1386 int ret = -ENOIOCTLCMD;
1387
1388
1389 /*
1390 * These ioctls don't rely on the hardware to be present.
1391 */
1392 switch (cmd) {
1393 case TIOCSERCONFIG:
1394 down_write(&tty->termios_rwsem);
1395 ret = uart_do_autoconfig(tty, state);
1396 up_write(&tty->termios_rwsem);
1397 break;
1398 }
1399
1400 if (ret != -ENOIOCTLCMD)
1401 goto out;
1402
1403 if (tty_io_error(tty)) {
1404 ret = -EIO;
1405 goto out;
1406 }
1407
1408 /*
1409 * The following should only be used when hardware is present.
1410 */
1411 switch (cmd) {
1412 case TIOCMIWAIT:
1413 ret = uart_wait_modem_status(state, arg);
1414 break;
1415 }
1416
1417 if (ret != -ENOIOCTLCMD)
1418 goto out;
1419
1420 mutex_lock(&port->mutex);
1421 uport = uart_port_check(state);
1422
1423 if (!uport || tty_io_error(tty)) {
1424 ret = -EIO;
1425 goto out_up;
1426 }
1427
1428 /*
1429 * All these rely on hardware being present and need to be
1430 * protected against the tty being hung up.
1431 */
1432
1433 switch (cmd) {
1434 case TIOCSERGETLSR: /* Get line status register */
1435 ret = uart_get_lsr_info(tty, state, uarg);
1436 break;
1437
1438 case TIOCGRS485:
1439 ret = uart_get_rs485_config(uport, uarg);
1440 break;
1441
1442 case TIOCSRS485:
1443 ret = uart_set_rs485_config(uport, uarg);
1444 break;
1445
1446 case TIOCSISO7816:
1447 ret = uart_set_iso7816_config(state->uart_port, uarg);
1448 break;
1449
1450 case TIOCGISO7816:
1451 ret = uart_get_iso7816_config(state->uart_port, uarg);
1452 break;
1453 default:
1454 if (uport->ops->ioctl)
1455 ret = uport->ops->ioctl(uport, cmd, arg);
1456 break;
1457 }
1458out_up:
1459 mutex_unlock(&port->mutex);
1460out:
1461 return ret;
1462}
1463
1464static void uart_set_ldisc(struct tty_struct *tty)
1465{
1466 struct uart_state *state = tty->driver_data;
1467 struct uart_port *uport;
1468
1469 mutex_lock(&state->port.mutex);
1470 uport = uart_port_check(state);
1471 if (uport && uport->ops->set_ldisc)
1472 uport->ops->set_ldisc(uport, &tty->termios);
1473 mutex_unlock(&state->port.mutex);
1474}
1475
1476static void uart_set_termios(struct tty_struct *tty,
1477 struct ktermios *old_termios)
1478{
1479 struct uart_state *state = tty->driver_data;
1480 struct uart_port *uport;
1481 unsigned int cflag = tty->termios.c_cflag;
1482 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1483 bool sw_changed = false;
1484
1485 mutex_lock(&state->port.mutex);
1486 uport = uart_port_check(state);
1487 if (!uport)
1488 goto out;
1489
1490 /*
1491 * Drivers doing software flow control also need to know
1492 * about changes to these input settings.
1493 */
1494 if (uport->flags & UPF_SOFT_FLOW) {
1495 iflag_mask |= IXANY|IXON|IXOFF;
1496 sw_changed =
1497 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1498 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1499 }
1500
1501 /*
1502 * These are the bits that are used to setup various
1503 * flags in the low level driver. We can ignore the Bfoo
1504 * bits in c_cflag; c_[io]speed will always be set
1505 * appropriately by set_termios() in tty_ioctl.c
1506 */
1507 if ((cflag ^ old_termios->c_cflag) == 0 &&
1508 tty->termios.c_ospeed == old_termios->c_ospeed &&
1509 tty->termios.c_ispeed == old_termios->c_ispeed &&
1510 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1511 !sw_changed) {
1512 goto out;
1513 }
1514
1515 uart_change_speed(tty, state, old_termios);
1516 /* reload cflag from termios; port driver may have overridden flags */
1517 cflag = tty->termios.c_cflag;
1518
1519 /* Handle transition to B0 status */
1520 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1521 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1522 /* Handle transition away from B0 status */
1523 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1524 unsigned int mask = TIOCM_DTR;
1525 if (!(cflag & CRTSCTS) || !tty_throttled(tty))
1526 mask |= TIOCM_RTS;
1527 uart_set_mctrl(uport, mask);
1528 }
1529out:
1530 mutex_unlock(&state->port.mutex);
1531}
1532
1533/*
1534 * Calls to uart_close() are serialised via the tty_lock in
1535 * drivers/tty/tty_io.c:tty_release()
1536 * drivers/tty/tty_io.c:do_tty_hangup()
1537 */
1538static void uart_close(struct tty_struct *tty, struct file *filp)
1539{
1540 struct uart_state *state = tty->driver_data;
1541
1542 if (!state) {
1543 struct uart_driver *drv = tty->driver->driver_state;
1544 struct tty_port *port;
1545
1546 state = drv->state + tty->index;
1547 port = &state->port;
1548 spin_lock_irq(&port->lock);
1549 --port->count;
1550 spin_unlock_irq(&port->lock);
1551 return;
1552 }
1553
1554 pr_debug("uart_close(%d) called\n", tty->index);
1555
1556 tty_port_close(tty->port, tty, filp);
1557}
1558
1559static void uart_tty_port_shutdown(struct tty_port *port)
1560{
1561 struct uart_state *state = container_of(port, struct uart_state, port);
1562 struct uart_port *uport = uart_port_check(state);
1563
1564 /*
1565 * At this point, we stop accepting input. To do this, we
1566 * disable the receive line status interrupts.
1567 */
1568 if (WARN(!uport, "detached port still initialized!\n"))
1569 return;
1570
1571 spin_lock_irq(&uport->lock);
1572 uport->ops->stop_rx(uport);
1573 spin_unlock_irq(&uport->lock);
1574
1575 uart_port_shutdown(port);
1576
1577 /*
1578 * It's possible for shutdown to be called after suspend if we get
1579 * a DCD drop (hangup) at just the right time. Clear suspended bit so
1580 * we don't try to resume a port that has been shutdown.
1581 */
1582 tty_port_set_suspended(port, 0);
1583
1584 uart_change_pm(state, UART_PM_STATE_OFF);
1585
1586}
1587
1588static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1589{
1590 struct uart_state *state = tty->driver_data;
1591 struct uart_port *port;
1592 unsigned long char_time, expire;
1593
1594 port = uart_port_ref(state);
1595 if (!port)
1596 return;
1597
1598 if (port->type == PORT_UNKNOWN || port->fifosize == 0) {
1599 uart_port_deref(port);
1600 return;
1601 }
1602
1603 /*
1604 * Set the check interval to be 1/5 of the estimated time to
1605 * send a single character, and make it at least 1. The check
1606 * interval should also be less than the timeout.
1607 *
1608 * Note: we have to use pretty tight timings here to satisfy
1609 * the NIST-PCTS.
1610 */
1611 char_time = (port->timeout - HZ/50) / port->fifosize;
1612 char_time = char_time / 5;
1613 if (char_time == 0)
1614 char_time = 1;
1615 if (timeout && timeout < char_time)
1616 char_time = timeout;
1617
1618 /*
1619 * If the transmitter hasn't cleared in twice the approximate
1620 * amount of time to send the entire FIFO, it probably won't
1621 * ever clear. This assumes the UART isn't doing flow
1622 * control, which is currently the case. Hence, if it ever
1623 * takes longer than port->timeout, this is probably due to a
1624 * UART bug of some kind. So, we clamp the timeout parameter at
1625 * 2*port->timeout.
1626 */
1627 if (timeout == 0 || timeout > 2 * port->timeout)
1628 timeout = 2 * port->timeout;
1629
1630 expire = jiffies + timeout;
1631
1632 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1633 port->line, jiffies, expire);
1634
1635 /*
1636 * Check whether the transmitter is empty every 'char_time'.
1637 * 'timeout' / 'expire' give us the maximum amount of time
1638 * we wait.
1639 */
1640 while (!port->ops->tx_empty(port)) {
1641 msleep_interruptible(jiffies_to_msecs(char_time));
1642 if (signal_pending(current))
1643 break;
1644 if (time_after(jiffies, expire))
1645 break;
1646 }
1647 uart_port_deref(port);
1648}
1649
1650/*
1651 * Calls to uart_hangup() are serialised by the tty_lock in
1652 * drivers/tty/tty_io.c:do_tty_hangup()
1653 * This runs from a workqueue and can sleep for a _short_ time only.
1654 */
1655static void uart_hangup(struct tty_struct *tty)
1656{
1657 struct uart_state *state = tty->driver_data;
1658 struct tty_port *port = &state->port;
1659 struct uart_port *uport;
1660 unsigned long flags;
1661
1662 pr_debug("uart_hangup(%d)\n", tty->index);
1663
1664 mutex_lock(&port->mutex);
1665 uport = uart_port_check(state);
1666 WARN(!uport, "hangup of detached port!\n");
1667
1668 if (tty_port_active(port)) {
1669 uart_flush_buffer(tty);
1670 uart_shutdown(tty, state);
1671 spin_lock_irqsave(&port->lock, flags);
1672 port->count = 0;
1673 spin_unlock_irqrestore(&port->lock, flags);
1674 tty_port_set_active(port, 0);
1675 tty_port_tty_set(port, NULL);
1676 if (uport && !uart_console(uport))
1677 uart_change_pm(state, UART_PM_STATE_OFF);
1678 wake_up_interruptible(&port->open_wait);
1679 wake_up_interruptible(&port->delta_msr_wait);
1680 }
1681 mutex_unlock(&port->mutex);
1682}
1683
1684/* uport == NULL if uart_port has already been removed */
1685static void uart_port_shutdown(struct tty_port *port)
1686{
1687 struct uart_state *state = container_of(port, struct uart_state, port);
1688 struct uart_port *uport = uart_port_check(state);
1689
1690 /*
1691 * clear delta_msr_wait queue to avoid mem leaks: we may free
1692 * the irq here so the queue might never be woken up. Note
1693 * that we won't end up waiting on delta_msr_wait again since
1694 * any outstanding file descriptors should be pointing at
1695 * hung_up_tty_fops now.
1696 */
1697 wake_up_interruptible(&port->delta_msr_wait);
1698
1699 /*
1700 * Free the IRQ and disable the port.
1701 */
1702 if (uport)
1703 uport->ops->shutdown(uport);
1704
1705 /*
1706 * Ensure that the IRQ handler isn't running on another CPU.
1707 */
1708 if (uport)
1709 synchronize_irq(uport->irq);
1710}
1711
1712static int uart_carrier_raised(struct tty_port *port)
1713{
1714 struct uart_state *state = container_of(port, struct uart_state, port);
1715 struct uart_port *uport;
1716 int mctrl;
1717
1718 uport = uart_port_ref(state);
1719 /*
1720 * Should never observe uport == NULL since checks for hangup should
1721 * abort the tty_port_block_til_ready() loop before checking for carrier
1722 * raised -- but report carrier raised if it does anyway so open will
1723 * continue and not sleep
1724 */
1725 if (WARN_ON(!uport))
1726 return 1;
1727 spin_lock_irq(&uport->lock);
1728 uart_enable_ms(uport);
1729 mctrl = uport->ops->get_mctrl(uport);
1730 spin_unlock_irq(&uport->lock);
1731 uart_port_deref(uport);
1732 if (mctrl & TIOCM_CAR)
1733 return 1;
1734 return 0;
1735}
1736
1737static void uart_dtr_rts(struct tty_port *port, int raise)
1738{
1739 struct uart_state *state = container_of(port, struct uart_state, port);
1740 struct uart_port *uport;
1741
1742 uport = uart_port_ref(state);
1743 if (!uport)
1744 return;
1745 uart_port_dtr_rts(uport, raise);
1746 uart_port_deref(uport);
1747}
1748
1749static int uart_install(struct tty_driver *driver, struct tty_struct *tty)
1750{
1751 struct uart_driver *drv = driver->driver_state;
1752 struct uart_state *state = drv->state + tty->index;
1753
1754 tty->driver_data = state;
1755
1756 return tty_standard_install(driver, tty);
1757}
1758
1759/*
1760 * Calls to uart_open are serialised by the tty_lock in
1761 * drivers/tty/tty_io.c:tty_open()
1762 * Note that if this fails, then uart_close() _will_ be called.
1763 *
1764 * In time, we want to scrap the "opening nonpresent ports"
1765 * behaviour and implement an alternative way for setserial
1766 * to set base addresses/ports/types. This will allow us to
1767 * get rid of a certain amount of extra tests.
1768 */
1769static int uart_open(struct tty_struct *tty, struct file *filp)
1770{
1771 struct uart_state *state = tty->driver_data;
1772 int retval;
1773
1774 retval = tty_port_open(&state->port, tty, filp);
1775 if (retval > 0)
1776 retval = 0;
1777
1778 return retval;
1779}
1780
1781static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1782{
1783 struct uart_state *state = container_of(port, struct uart_state, port);
1784 struct uart_port *uport;
1785 int ret;
1786
1787 uport = uart_port_check(state);
1788 if (!uport || uport->flags & UPF_DEAD)
1789 return -ENXIO;
1790
1791 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
1792
1793 /*
1794 * Start up the serial port.
1795 */
1796 ret = uart_startup(tty, state, 0);
1797 if (ret > 0)
1798 tty_port_set_active(port, 1);
1799
1800 return ret;
1801}
1802
1803static const char *uart_type(struct uart_port *port)
1804{
1805 const char *str = NULL;
1806
1807 if (port->ops->type)
1808 str = port->ops->type(port);
1809
1810 if (!str)
1811 str = "unknown";
1812
1813 return str;
1814}
1815
1816#ifdef CONFIG_PROC_FS
1817
1818static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1819{
1820 struct uart_state *state = drv->state + i;
1821 struct tty_port *port = &state->port;
1822 enum uart_pm_state pm_state;
1823 struct uart_port *uport;
1824 char stat_buf[32];
1825 unsigned int status;
1826 int mmio;
1827
1828 mutex_lock(&port->mutex);
1829 uport = uart_port_check(state);
1830 if (!uport)
1831 goto out;
1832
1833 mmio = uport->iotype >= UPIO_MEM;
1834 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1835 uport->line, uart_type(uport),
1836 mmio ? "mmio:0x" : "port:",
1837 mmio ? (unsigned long long)uport->mapbase
1838 : (unsigned long long)uport->iobase,
1839 uport->irq);
1840
1841 if (uport->type == PORT_UNKNOWN) {
1842 seq_putc(m, '\n');
1843 goto out;
1844 }
1845
1846 if (capable(CAP_SYS_ADMIN)) {
1847 pm_state = state->pm_state;
1848 if (pm_state != UART_PM_STATE_ON)
1849 uart_change_pm(state, UART_PM_STATE_ON);
1850 spin_lock_irq(&uport->lock);
1851 status = uport->ops->get_mctrl(uport);
1852 spin_unlock_irq(&uport->lock);
1853 if (pm_state != UART_PM_STATE_ON)
1854 uart_change_pm(state, pm_state);
1855
1856 seq_printf(m, " tx:%d rx:%d",
1857 uport->icount.tx, uport->icount.rx);
1858 if (uport->icount.frame)
1859 seq_printf(m, " fe:%d", uport->icount.frame);
1860 if (uport->icount.parity)
1861 seq_printf(m, " pe:%d", uport->icount.parity);
1862 if (uport->icount.brk)
1863 seq_printf(m, " brk:%d", uport->icount.brk);
1864 if (uport->icount.overrun)
1865 seq_printf(m, " oe:%d", uport->icount.overrun);
1866 if (uport->icount.buf_overrun)
1867 seq_printf(m, " bo:%d", uport->icount.buf_overrun);
1868
1869#define INFOBIT(bit, str) \
1870 if (uport->mctrl & (bit)) \
1871 strncat(stat_buf, (str), sizeof(stat_buf) - \
1872 strlen(stat_buf) - 2)
1873#define STATBIT(bit, str) \
1874 if (status & (bit)) \
1875 strncat(stat_buf, (str), sizeof(stat_buf) - \
1876 strlen(stat_buf) - 2)
1877
1878 stat_buf[0] = '\0';
1879 stat_buf[1] = '\0';
1880 INFOBIT(TIOCM_RTS, "|RTS");
1881 STATBIT(TIOCM_CTS, "|CTS");
1882 INFOBIT(TIOCM_DTR, "|DTR");
1883 STATBIT(TIOCM_DSR, "|DSR");
1884 STATBIT(TIOCM_CAR, "|CD");
1885 STATBIT(TIOCM_RNG, "|RI");
1886 if (stat_buf[0])
1887 stat_buf[0] = ' ';
1888
1889 seq_puts(m, stat_buf);
1890 }
1891 seq_putc(m, '\n');
1892#undef STATBIT
1893#undef INFOBIT
1894out:
1895 mutex_unlock(&port->mutex);
1896}
1897
1898static int uart_proc_show(struct seq_file *m, void *v)
1899{
1900 struct tty_driver *ttydrv = m->private;
1901 struct uart_driver *drv = ttydrv->driver_state;
1902 int i;
1903
1904 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
1905 for (i = 0; i < drv->nr; i++)
1906 uart_line_info(m, drv, i);
1907 return 0;
1908}
1909#endif
1910
1911#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1912/**
1913 * uart_console_write - write a console message to a serial port
1914 * @port: the port to write the message
1915 * @s: array of characters
1916 * @count: number of characters in string to write
1917 * @putchar: function to write character to port
1918 */
1919void uart_console_write(struct uart_port *port, const char *s,
1920 unsigned int count,
1921 void (*putchar)(struct uart_port *, int))
1922{
1923 unsigned int i;
1924
1925 for (i = 0; i < count; i++, s++) {
1926 if (*s == '\n')
1927 putchar(port, '\r');
1928 putchar(port, *s);
1929 }
1930}
1931EXPORT_SYMBOL_GPL(uart_console_write);
1932
1933/*
1934 * Check whether an invalid uart number has been specified, and
1935 * if so, search for the first available port that does have
1936 * console support.
1937 */
1938struct uart_port * __init
1939uart_get_console(struct uart_port *ports, int nr, struct console *co)
1940{
1941 int idx = co->index;
1942
1943 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1944 ports[idx].membase == NULL))
1945 for (idx = 0; idx < nr; idx++)
1946 if (ports[idx].iobase != 0 ||
1947 ports[idx].membase != NULL)
1948 break;
1949
1950 co->index = idx;
1951
1952 return ports + idx;
1953}
1954
1955/**
1956 * uart_parse_earlycon - Parse earlycon options
1957 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1958 * @iotype: ptr for decoded iotype (out)
1959 * @addr: ptr for decoded mapbase/iobase (out)
1960 * @options: ptr for <options> field; NULL if not present (out)
1961 *
1962 * Decodes earlycon kernel command line parameters of the form
1963 * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1964 * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1965 *
1966 * The optional form
1967 *
1968 * earlycon=<name>,0x<addr>,<options>
1969 * console=<name>,0x<addr>,<options>
1970 *
1971 * is also accepted; the returned @iotype will be UPIO_MEM.
1972 *
1973 * Returns 0 on success or -EINVAL on failure
1974 */
1975int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
1976 char **options)
1977{
1978 if (strncmp(p, "mmio,", 5) == 0) {
1979 *iotype = UPIO_MEM;
1980 p += 5;
1981 } else if (strncmp(p, "mmio16,", 7) == 0) {
1982 *iotype = UPIO_MEM16;
1983 p += 7;
1984 } else if (strncmp(p, "mmio32,", 7) == 0) {
1985 *iotype = UPIO_MEM32;
1986 p += 7;
1987 } else if (strncmp(p, "mmio32be,", 9) == 0) {
1988 *iotype = UPIO_MEM32BE;
1989 p += 9;
1990 } else if (strncmp(p, "mmio32native,", 13) == 0) {
1991 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
1992 UPIO_MEM32BE : UPIO_MEM32;
1993 p += 13;
1994 } else if (strncmp(p, "io,", 3) == 0) {
1995 *iotype = UPIO_PORT;
1996 p += 3;
1997 } else if (strncmp(p, "0x", 2) == 0) {
1998 *iotype = UPIO_MEM;
1999 } else {
2000 return -EINVAL;
2001 }
2002
2003 /*
2004 * Before you replace it with kstrtoull(), think about options separator
2005 * (',') it will not tolerate
2006 */
2007 *addr = simple_strtoull(p, NULL, 0);
2008 p = strchr(p, ',');
2009 if (p)
2010 p++;
2011
2012 *options = p;
2013 return 0;
2014}
2015EXPORT_SYMBOL_GPL(uart_parse_earlycon);
2016
2017/**
2018 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
2019 * @options: pointer to option string
2020 * @baud: pointer to an 'int' variable for the baud rate.
2021 * @parity: pointer to an 'int' variable for the parity.
2022 * @bits: pointer to an 'int' variable for the number of data bits.
2023 * @flow: pointer to an 'int' variable for the flow control character.
2024 *
2025 * uart_parse_options decodes a string containing the serial console
2026 * options. The format of the string is <baud><parity><bits><flow>,
2027 * eg: 115200n8r
2028 */
2029void
2030uart_parse_options(const char *options, int *baud, int *parity,
2031 int *bits, int *flow)
2032{
2033 const char *s = options;
2034
2035 *baud = simple_strtoul(s, NULL, 10);
2036 while (*s >= '0' && *s <= '9')
2037 s++;
2038 if (*s)
2039 *parity = *s++;
2040 if (*s)
2041 *bits = *s++ - '0';
2042 if (*s)
2043 *flow = *s;
2044}
2045EXPORT_SYMBOL_GPL(uart_parse_options);
2046
2047/**
2048 * uart_set_options - setup the serial console parameters
2049 * @port: pointer to the serial ports uart_port structure
2050 * @co: console pointer
2051 * @baud: baud rate
2052 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
2053 * @bits: number of data bits
2054 * @flow: flow control character - 'r' (rts)
2055 */
2056int
2057uart_set_options(struct uart_port *port, struct console *co,
2058 int baud, int parity, int bits, int flow)
2059{
2060 struct ktermios termios;
2061 static struct ktermios dummy;
2062
2063 /*
2064 * Ensure that the serial console lock is initialised
2065 * early.
2066 * If this port is a console, then the spinlock is already
2067 * initialised.
2068 */
2069 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
2070 spin_lock_init(&port->lock);
2071 lockdep_set_class(&port->lock, &port_lock_key);
2072 }
2073
2074 memset(&termios, 0, sizeof(struct ktermios));
2075
2076 termios.c_cflag |= CREAD | HUPCL | CLOCAL;
2077 tty_termios_encode_baud_rate(&termios, baud, baud);
2078
2079 if (bits == 7)
2080 termios.c_cflag |= CS7;
2081 else
2082 termios.c_cflag |= CS8;
2083
2084 switch (parity) {
2085 case 'o': case 'O':
2086 termios.c_cflag |= PARODD;
2087 /*fall through*/
2088 case 'e': case 'E':
2089 termios.c_cflag |= PARENB;
2090 break;
2091 }
2092
2093 if (flow == 'r')
2094 termios.c_cflag |= CRTSCTS;
2095
2096 /*
2097 * some uarts on other side don't support no flow control.
2098 * So we set * DTR in host uart to make them happy
2099 */
2100 port->mctrl |= TIOCM_DTR;
2101
2102 port->ops->set_termios(port, &termios, &dummy);
2103 /*
2104 * Allow the setting of the UART parameters with a NULL console
2105 * too:
2106 */
2107 if (co)
2108 co->cflag = termios.c_cflag;
2109
2110 return 0;
2111}
2112EXPORT_SYMBOL_GPL(uart_set_options);
2113#endif /* CONFIG_SERIAL_CORE_CONSOLE */
2114
2115/**
2116 * uart_change_pm - set power state of the port
2117 *
2118 * @state: port descriptor
2119 * @pm_state: new state
2120 *
2121 * Locking: port->mutex has to be held
2122 */
2123static void uart_change_pm(struct uart_state *state,
2124 enum uart_pm_state pm_state)
2125{
2126 struct uart_port *port = uart_port_check(state);
2127
2128 if (state->pm_state != pm_state) {
2129 if (port && port->ops->pm)
2130 port->ops->pm(port, pm_state, state->pm_state);
2131 state->pm_state = pm_state;
2132 }
2133}
2134
2135struct uart_match {
2136 struct uart_port *port;
2137 struct uart_driver *driver;
2138};
2139
2140static int serial_match_port(struct device *dev, void *data)
2141{
2142 struct uart_match *match = data;
2143 struct tty_driver *tty_drv = match->driver->tty_driver;
2144 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
2145 match->port->line;
2146
2147 return dev->devt == devt; /* Actually, only one tty per port */
2148}
2149
2150int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
2151{
2152 struct uart_state *state = drv->state + uport->line;
2153 struct tty_port *port = &state->port;
2154 struct device *tty_dev;
2155 struct uart_match match = {uport, drv};
2156
2157 mutex_lock(&port->mutex);
2158
2159 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2160 if (tty_dev && device_may_wakeup(tty_dev)) {
2161 enable_irq_wake(uport->irq);
2162 put_device(tty_dev);
2163 mutex_unlock(&port->mutex);
2164 return 0;
2165 }
2166 put_device(tty_dev);
2167
2168 /* Nothing to do if the console is not suspending */
2169 if (!console_suspend_enabled && uart_console(uport))
2170 goto unlock;
2171
2172 uport->suspended = 1;
2173
2174 if (tty_port_initialized(port)) {
2175 const struct uart_ops *ops = uport->ops;
2176 int tries;
2177
2178 tty_port_set_suspended(port, 1);
2179 tty_port_set_initialized(port, 0);
2180
2181 spin_lock_irq(&uport->lock);
2182 ops->stop_tx(uport);
2183 ops->set_mctrl(uport, 0);
2184 ops->stop_rx(uport);
2185 spin_unlock_irq(&uport->lock);
2186
2187 /*
2188 * Wait for the transmitter to empty.
2189 */
2190 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2191 msleep(10);
2192 if (!tries)
2193 dev_err(uport->dev, "%s: Unable to drain transmitter\n",
2194 uport->name);
2195
2196 ops->shutdown(uport);
2197 }
2198
2199 /*
2200 * Disable the console device before suspending.
2201 */
2202 if (uart_console(uport))
2203 console_stop(uport->cons);
2204
2205 uart_change_pm(state, UART_PM_STATE_OFF);
2206unlock:
2207 mutex_unlock(&port->mutex);
2208
2209 return 0;
2210}
2211
2212int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2213{
2214 struct uart_state *state = drv->state + uport->line;
2215 struct tty_port *port = &state->port;
2216 struct device *tty_dev;
2217 struct uart_match match = {uport, drv};
2218 struct ktermios termios;
2219
2220 mutex_lock(&port->mutex);
2221
2222 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2223 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2224 if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq))))
2225 disable_irq_wake(uport->irq);
2226 put_device(tty_dev);
2227 mutex_unlock(&port->mutex);
2228 return 0;
2229 }
2230 put_device(tty_dev);
2231 uport->suspended = 0;
2232
2233 /*
2234 * Re-enable the console device after suspending.
2235 */
2236 if (uart_console(uport)) {
2237 /*
2238 * First try to use the console cflag setting.
2239 */
2240 memset(&termios, 0, sizeof(struct ktermios));
2241 termios.c_cflag = uport->cons->cflag;
2242
2243 /*
2244 * If that's unset, use the tty termios setting.
2245 */
2246 if (port->tty && termios.c_cflag == 0)
2247 termios = port->tty->termios;
2248
2249 if (console_suspend_enabled)
2250 uart_change_pm(state, UART_PM_STATE_ON);
2251 uport->ops->set_termios(uport, &termios, NULL);
2252 if (console_suspend_enabled)
2253 console_start(uport->cons);
2254 }
2255
2256 if (tty_port_suspended(port)) {
2257 const struct uart_ops *ops = uport->ops;
2258 int ret;
2259
2260 uart_change_pm(state, UART_PM_STATE_ON);
2261 spin_lock_irq(&uport->lock);
2262 ops->set_mctrl(uport, 0);
2263 spin_unlock_irq(&uport->lock);
2264 if (console_suspend_enabled || !uart_console(uport)) {
2265 /* Protected by port mutex for now */
2266 struct tty_struct *tty = port->tty;
2267 ret = ops->startup(uport);
2268 if (ret == 0) {
2269 if (tty)
2270 uart_change_speed(tty, state, NULL);
2271 spin_lock_irq(&uport->lock);
2272 ops->set_mctrl(uport, uport->mctrl);
2273 ops->start_tx(uport);
2274 spin_unlock_irq(&uport->lock);
2275 tty_port_set_initialized(port, 1);
2276 } else {
2277 /*
2278 * Failed to resume - maybe hardware went away?
2279 * Clear the "initialized" flag so we won't try
2280 * to call the low level drivers shutdown method.
2281 */
2282 uart_shutdown(tty, state);
2283 }
2284 }
2285
2286 tty_port_set_suspended(port, 0);
2287 }
2288
2289 mutex_unlock(&port->mutex);
2290
2291 return 0;
2292}
2293
2294static inline void
2295uart_report_port(struct uart_driver *drv, struct uart_port *port)
2296{
2297 char address[64];
2298
2299 switch (port->iotype) {
2300 case UPIO_PORT:
2301 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2302 break;
2303 case UPIO_HUB6:
2304 snprintf(address, sizeof(address),
2305 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2306 break;
2307 case UPIO_MEM:
2308 case UPIO_MEM16:
2309 case UPIO_MEM32:
2310 case UPIO_MEM32BE:
2311 case UPIO_AU:
2312 case UPIO_TSI:
2313 snprintf(address, sizeof(address),
2314 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2315 break;
2316 default:
2317 strlcpy(address, "*unknown*", sizeof(address));
2318 break;
2319 }
2320
2321 pr_info("%s%s%s at %s (irq = %d, base_baud = %d) is a %s\n",
2322 port->dev ? dev_name(port->dev) : "",
2323 port->dev ? ": " : "",
2324 port->name,
2325 address, port->irq, port->uartclk / 16, uart_type(port));
2326}
2327
2328static void
2329uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2330 struct uart_port *port)
2331{
2332 unsigned int flags;
2333
2334 /*
2335 * If there isn't a port here, don't do anything further.
2336 */
2337 if (!port->iobase && !port->mapbase && !port->membase)
2338 return;
2339
2340 /*
2341 * Now do the auto configuration stuff. Note that config_port
2342 * is expected to claim the resources and map the port for us.
2343 */
2344 flags = 0;
2345 if (port->flags & UPF_AUTO_IRQ)
2346 flags |= UART_CONFIG_IRQ;
2347 if (port->flags & UPF_BOOT_AUTOCONF) {
2348 if (!(port->flags & UPF_FIXED_TYPE)) {
2349 port->type = PORT_UNKNOWN;
2350 flags |= UART_CONFIG_TYPE;
2351 }
2352 port->ops->config_port(port, flags);
2353 }
2354
2355 if (port->type != PORT_UNKNOWN) {
2356 unsigned long flags;
2357
2358 uart_report_port(drv, port);
2359
2360 /* Power up port for set_mctrl() */
2361 uart_change_pm(state, UART_PM_STATE_ON);
2362
2363 /*
2364 * Ensure that the modem control lines are de-activated.
2365 * keep the DTR setting that is set in uart_set_options()
2366 * We probably don't need a spinlock around this, but
2367 */
2368 spin_lock_irqsave(&port->lock, flags);
2369 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2370 spin_unlock_irqrestore(&port->lock, flags);
2371
2372 /*
2373 * If this driver supports console, and it hasn't been
2374 * successfully registered yet, try to re-register it.
2375 * It may be that the port was not available.
2376 */
2377 if (port->cons && !(port->cons->flags & CON_ENABLED))
2378 register_console(port->cons);
2379
2380 /*
2381 * Power down all ports by default, except the
2382 * console if we have one.
2383 */
2384 if (!uart_console(port))
2385 uart_change_pm(state, UART_PM_STATE_OFF);
2386 }
2387}
2388
2389#ifdef CONFIG_CONSOLE_POLL
2390
2391static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2392{
2393 struct uart_driver *drv = driver->driver_state;
2394 struct uart_state *state = drv->state + line;
2395 struct tty_port *tport;
2396 struct uart_port *port;
2397 int baud = 9600;
2398 int bits = 8;
2399 int parity = 'n';
2400 int flow = 'n';
2401 int ret = 0;
2402
2403 tport = &state->port;
2404 mutex_lock(&tport->mutex);
2405
2406 port = uart_port_check(state);
2407 if (!port || !(port->ops->poll_get_char && port->ops->poll_put_char)) {
2408 ret = -1;
2409 goto out;
2410 }
2411
2412 if (port->ops->poll_init) {
2413 /*
2414 * We don't set initialized as we only initialized the hw,
2415 * e.g. state->xmit is still uninitialized.
2416 */
2417 if (!tty_port_initialized(tport))
2418 ret = port->ops->poll_init(port);
2419 }
2420
2421 if (!ret && options) {
2422 uart_parse_options(options, &baud, &parity, &bits, &flow);
2423 ret = uart_set_options(port, NULL, baud, parity, bits, flow);
2424 }
2425out:
2426 mutex_unlock(&tport->mutex);
2427 return ret;
2428}
2429
2430static int uart_poll_get_char(struct tty_driver *driver, int line)
2431{
2432 struct uart_driver *drv = driver->driver_state;
2433 struct uart_state *state = drv->state + line;
2434 struct uart_port *port;
2435 int ret = -1;
2436
2437 port = uart_port_ref(state);
2438 if (port) {
2439 ret = port->ops->poll_get_char(port);
2440 uart_port_deref(port);
2441 }
2442
2443 return ret;
2444}
2445
2446static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2447{
2448 struct uart_driver *drv = driver->driver_state;
2449 struct uart_state *state = drv->state + line;
2450 struct uart_port *port;
2451
2452 port = uart_port_ref(state);
2453 if (!port)
2454 return;
2455
2456 if (ch == '\n')
2457 port->ops->poll_put_char(port, '\r');
2458 port->ops->poll_put_char(port, ch);
2459 uart_port_deref(port);
2460}
2461#endif
2462
2463static const struct tty_operations uart_ops = {
2464 .install = uart_install,
2465 .open = uart_open,
2466 .close = uart_close,
2467 .write = uart_write,
2468 .put_char = uart_put_char,
2469 .flush_chars = uart_flush_chars,
2470 .write_room = uart_write_room,
2471 .chars_in_buffer= uart_chars_in_buffer,
2472 .flush_buffer = uart_flush_buffer,
2473 .ioctl = uart_ioctl,
2474 .throttle = uart_throttle,
2475 .unthrottle = uart_unthrottle,
2476 .send_xchar = uart_send_xchar,
2477 .set_termios = uart_set_termios,
2478 .set_ldisc = uart_set_ldisc,
2479 .stop = uart_stop,
2480 .start = uart_start,
2481 .hangup = uart_hangup,
2482 .break_ctl = uart_break_ctl,
2483 .wait_until_sent= uart_wait_until_sent,
2484#ifdef CONFIG_PROC_FS
2485 .proc_show = uart_proc_show,
2486#endif
2487 .tiocmget = uart_tiocmget,
2488 .tiocmset = uart_tiocmset,
2489 .set_serial = uart_set_info_user,
2490 .get_serial = uart_get_info_user,
2491 .get_icount = uart_get_icount,
2492#ifdef CONFIG_CONSOLE_POLL
2493 .poll_init = uart_poll_init,
2494 .poll_get_char = uart_poll_get_char,
2495 .poll_put_char = uart_poll_put_char,
2496#endif
2497};
2498
2499static const struct tty_port_operations uart_port_ops = {
2500 .carrier_raised = uart_carrier_raised,
2501 .dtr_rts = uart_dtr_rts,
2502 .activate = uart_port_activate,
2503 .shutdown = uart_tty_port_shutdown,
2504};
2505
2506/**
2507 * uart_register_driver - register a driver with the uart core layer
2508 * @drv: low level driver structure
2509 *
2510 * Register a uart driver with the core driver. We in turn register
2511 * with the tty layer, and initialise the core driver per-port state.
2512 *
2513 * We have a proc file in /proc/tty/driver which is named after the
2514 * normal driver.
2515 *
2516 * drv->port should be NULL, and the per-port structures should be
2517 * registered using uart_add_one_port after this call has succeeded.
2518 */
2519int uart_register_driver(struct uart_driver *drv)
2520{
2521 struct tty_driver *normal;
2522 int i, retval = -ENOMEM;
2523
2524 BUG_ON(drv->state);
2525
2526 /*
2527 * Maybe we should be using a slab cache for this, especially if
2528 * we have a large number of ports to handle.
2529 */
2530 drv->state = kcalloc(drv->nr, sizeof(struct uart_state), GFP_KERNEL);
2531 if (!drv->state)
2532 goto out;
2533
2534 normal = alloc_tty_driver(drv->nr);
2535 if (!normal)
2536 goto out_kfree;
2537
2538 drv->tty_driver = normal;
2539
2540 normal->driver_name = drv->driver_name;
2541 normal->name = drv->dev_name;
2542 normal->major = drv->major;
2543 normal->minor_start = drv->minor;
2544 normal->type = TTY_DRIVER_TYPE_SERIAL;
2545 normal->subtype = SERIAL_TYPE_NORMAL;
2546 normal->init_termios = tty_std_termios;
2547 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2548 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2549 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2550 normal->driver_state = drv;
2551 tty_set_operations(normal, &uart_ops);
2552
2553 /*
2554 * Initialise the UART state(s).
2555 */
2556 for (i = 0; i < drv->nr; i++) {
2557 struct uart_state *state = drv->state + i;
2558 struct tty_port *port = &state->port;
2559
2560 tty_port_init(port);
2561 port->ops = &uart_port_ops;
2562 }
2563
2564 retval = tty_register_driver(normal);
2565 if (retval >= 0)
2566 return retval;
2567
2568 for (i = 0; i < drv->nr; i++)
2569 tty_port_destroy(&drv->state[i].port);
2570 put_tty_driver(normal);
2571out_kfree:
2572 kfree(drv->state);
2573out:
2574 return retval;
2575}
2576
2577/**
2578 * uart_unregister_driver - remove a driver from the uart core layer
2579 * @drv: low level driver structure
2580 *
2581 * Remove all references to a driver from the core driver. The low
2582 * level driver must have removed all its ports via the
2583 * uart_remove_one_port() if it registered them with uart_add_one_port().
2584 * (ie, drv->port == NULL)
2585 */
2586void uart_unregister_driver(struct uart_driver *drv)
2587{
2588 struct tty_driver *p = drv->tty_driver;
2589 unsigned int i;
2590
2591 tty_unregister_driver(p);
2592 put_tty_driver(p);
2593 for (i = 0; i < drv->nr; i++)
2594 tty_port_destroy(&drv->state[i].port);
2595 kfree(drv->state);
2596 drv->state = NULL;
2597 drv->tty_driver = NULL;
2598}
2599
2600struct tty_driver *uart_console_device(struct console *co, int *index)
2601{
2602 struct uart_driver *p = co->data;
2603 *index = co->index;
2604 return p->tty_driver;
2605}
2606
2607static ssize_t uart_get_attr_uartclk(struct device *dev,
2608 struct device_attribute *attr, char *buf)
2609{
2610 struct serial_struct tmp;
2611 struct tty_port *port = dev_get_drvdata(dev);
2612
2613 uart_get_info(port, &tmp);
2614 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2615}
2616
2617static ssize_t uart_get_attr_type(struct device *dev,
2618 struct device_attribute *attr, char *buf)
2619{
2620 struct serial_struct tmp;
2621 struct tty_port *port = dev_get_drvdata(dev);
2622
2623 uart_get_info(port, &tmp);
2624 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2625}
2626static ssize_t uart_get_attr_line(struct device *dev,
2627 struct device_attribute *attr, char *buf)
2628{
2629 struct serial_struct tmp;
2630 struct tty_port *port = dev_get_drvdata(dev);
2631
2632 uart_get_info(port, &tmp);
2633 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2634}
2635
2636static ssize_t uart_get_attr_port(struct device *dev,
2637 struct device_attribute *attr, char *buf)
2638{
2639 struct serial_struct tmp;
2640 struct tty_port *port = dev_get_drvdata(dev);
2641 unsigned long ioaddr;
2642
2643 uart_get_info(port, &tmp);
2644 ioaddr = tmp.port;
2645 if (HIGH_BITS_OFFSET)
2646 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2647 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2648}
2649
2650static ssize_t uart_get_attr_irq(struct device *dev,
2651 struct device_attribute *attr, char *buf)
2652{
2653 struct serial_struct tmp;
2654 struct tty_port *port = dev_get_drvdata(dev);
2655
2656 uart_get_info(port, &tmp);
2657 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2658}
2659
2660static ssize_t uart_get_attr_flags(struct device *dev,
2661 struct device_attribute *attr, char *buf)
2662{
2663 struct serial_struct tmp;
2664 struct tty_port *port = dev_get_drvdata(dev);
2665
2666 uart_get_info(port, &tmp);
2667 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2668}
2669
2670static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2671 struct device_attribute *attr, char *buf)
2672{
2673 struct serial_struct tmp;
2674 struct tty_port *port = dev_get_drvdata(dev);
2675
2676 uart_get_info(port, &tmp);
2677 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2678}
2679
2680
2681static ssize_t uart_get_attr_close_delay(struct device *dev,
2682 struct device_attribute *attr, char *buf)
2683{
2684 struct serial_struct tmp;
2685 struct tty_port *port = dev_get_drvdata(dev);
2686
2687 uart_get_info(port, &tmp);
2688 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2689}
2690
2691
2692static ssize_t uart_get_attr_closing_wait(struct device *dev,
2693 struct device_attribute *attr, char *buf)
2694{
2695 struct serial_struct tmp;
2696 struct tty_port *port = dev_get_drvdata(dev);
2697
2698 uart_get_info(port, &tmp);
2699 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2700}
2701
2702static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2703 struct device_attribute *attr, char *buf)
2704{
2705 struct serial_struct tmp;
2706 struct tty_port *port = dev_get_drvdata(dev);
2707
2708 uart_get_info(port, &tmp);
2709 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2710}
2711
2712static ssize_t uart_get_attr_io_type(struct device *dev,
2713 struct device_attribute *attr, char *buf)
2714{
2715 struct serial_struct tmp;
2716 struct tty_port *port = dev_get_drvdata(dev);
2717
2718 uart_get_info(port, &tmp);
2719 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2720}
2721
2722static ssize_t uart_get_attr_iomem_base(struct device *dev,
2723 struct device_attribute *attr, char *buf)
2724{
2725 struct serial_struct tmp;
2726 struct tty_port *port = dev_get_drvdata(dev);
2727
2728 uart_get_info(port, &tmp);
2729 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2730}
2731
2732static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2733 struct device_attribute *attr, char *buf)
2734{
2735 struct serial_struct tmp;
2736 struct tty_port *port = dev_get_drvdata(dev);
2737
2738 uart_get_info(port, &tmp);
2739 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2740}
2741
2742static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2743static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2744static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2745static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2746static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2747static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2748static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2749static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2750static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2751static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2752static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2753static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2754static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2755
2756static struct attribute *tty_dev_attrs[] = {
2757 &dev_attr_type.attr,
2758 &dev_attr_line.attr,
2759 &dev_attr_port.attr,
2760 &dev_attr_irq.attr,
2761 &dev_attr_flags.attr,
2762 &dev_attr_xmit_fifo_size.attr,
2763 &dev_attr_uartclk.attr,
2764 &dev_attr_close_delay.attr,
2765 &dev_attr_closing_wait.attr,
2766 &dev_attr_custom_divisor.attr,
2767 &dev_attr_io_type.attr,
2768 &dev_attr_iomem_base.attr,
2769 &dev_attr_iomem_reg_shift.attr,
2770 NULL,
2771 };
2772
2773static const struct attribute_group tty_dev_attr_group = {
2774 .attrs = tty_dev_attrs,
2775 };
2776
2777/**
2778 * uart_add_one_port - attach a driver-defined port structure
2779 * @drv: pointer to the uart low level driver structure for this port
2780 * @uport: uart port structure to use for this port.
2781 *
2782 * This allows the driver to register its own uart_port structure
2783 * with the core driver. The main purpose is to allow the low
2784 * level uart drivers to expand uart_port, rather than having yet
2785 * more levels of structures.
2786 */
2787int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2788{
2789 struct uart_state *state;
2790 struct tty_port *port;
2791 int ret = 0;
2792 struct device *tty_dev;
2793 int num_groups;
2794
2795 BUG_ON(in_interrupt());
2796
2797 if (uport->line >= drv->nr)
2798 return -EINVAL;
2799
2800 state = drv->state + uport->line;
2801 port = &state->port;
2802
2803 mutex_lock(&port_mutex);
2804 mutex_lock(&port->mutex);
2805 if (state->uart_port) {
2806 ret = -EINVAL;
2807 goto out;
2808 }
2809
2810 /* Link the port to the driver state table and vice versa */
2811 atomic_set(&state->refcount, 1);
2812 init_waitqueue_head(&state->remove_wait);
2813 state->uart_port = uport;
2814 uport->state = state;
2815
2816 state->pm_state = UART_PM_STATE_UNDEFINED;
2817 uport->cons = drv->cons;
2818 uport->minor = drv->tty_driver->minor_start + uport->line;
2819 uport->name = kasprintf(GFP_KERNEL, "%s%d", drv->dev_name,
2820 drv->tty_driver->name_base + uport->line);
2821 if (!uport->name) {
2822 ret = -ENOMEM;
2823 goto out;
2824 }
2825
2826 /*
2827 * If this port is a console, then the spinlock is already
2828 * initialised.
2829 */
2830 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2831 spin_lock_init(&uport->lock);
2832 lockdep_set_class(&uport->lock, &port_lock_key);
2833 }
2834 if (uport->cons && uport->dev)
2835 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2836
2837 uart_configure_port(drv, state, uport);
2838
2839 port->console = uart_console(uport);
2840
2841 num_groups = 2;
2842 if (uport->attr_group)
2843 num_groups++;
2844
2845 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2846 GFP_KERNEL);
2847 if (!uport->tty_groups) {
2848 ret = -ENOMEM;
2849 goto out;
2850 }
2851 uport->tty_groups[0] = &tty_dev_attr_group;
2852 if (uport->attr_group)
2853 uport->tty_groups[1] = uport->attr_group;
2854
2855 /*
2856 * Register the port whether it's detected or not. This allows
2857 * setserial to be used to alter this port's parameters.
2858 */
2859 tty_dev = tty_port_register_device_attr_serdev(port, drv->tty_driver,
2860 uport->line, uport->dev, port, uport->tty_groups);
2861 if (!IS_ERR(tty_dev)) {
2862 device_set_wakeup_capable(tty_dev, 1);
2863 } else {
2864 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2865 uport->line);
2866 }
2867
2868 /*
2869 * Ensure UPF_DEAD is not set.
2870 */
2871 uport->flags &= ~UPF_DEAD;
2872
2873 out:
2874 mutex_unlock(&port->mutex);
2875 mutex_unlock(&port_mutex);
2876
2877 return ret;
2878}
2879
2880/**
2881 * uart_remove_one_port - detach a driver defined port structure
2882 * @drv: pointer to the uart low level driver structure for this port
2883 * @uport: uart port structure for this port
2884 *
2885 * This unhooks (and hangs up) the specified port structure from the
2886 * core driver. No further calls will be made to the low-level code
2887 * for this port.
2888 */
2889int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2890{
2891 struct uart_state *state = drv->state + uport->line;
2892 struct tty_port *port = &state->port;
2893 struct uart_port *uart_port;
2894 struct tty_struct *tty;
2895 int ret = 0;
2896
2897 BUG_ON(in_interrupt());
2898
2899 mutex_lock(&port_mutex);
2900
2901 /*
2902 * Mark the port "dead" - this prevents any opens from
2903 * succeeding while we shut down the port.
2904 */
2905 mutex_lock(&port->mutex);
2906 uart_port = uart_port_check(state);
2907 if (uart_port != uport)
2908 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2909 uart_port, uport);
2910
2911 if (!uart_port) {
2912 mutex_unlock(&port->mutex);
2913 ret = -EINVAL;
2914 goto out;
2915 }
2916 uport->flags |= UPF_DEAD;
2917 mutex_unlock(&port->mutex);
2918
2919 /*
2920 * Remove the devices from the tty layer
2921 */
2922 tty_port_unregister_device(port, drv->tty_driver, uport->line);
2923
2924 tty = tty_port_tty_get(port);
2925 if (tty) {
2926 tty_vhangup(port->tty);
2927 tty_kref_put(tty);
2928 }
2929
2930 /*
2931 * If the port is used as a console, unregister it
2932 */
2933 if (uart_console(uport))
2934 unregister_console(uport->cons);
2935
2936 /*
2937 * Free the port IO and memory resources, if any.
2938 */
2939 if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
2940 uport->ops->release_port(uport);
2941 kfree(uport->tty_groups);
2942 kfree(uport->name);
2943
2944 /*
2945 * Indicate that there isn't a port here anymore.
2946 */
2947 uport->type = PORT_UNKNOWN;
2948
2949 mutex_lock(&port->mutex);
2950 WARN_ON(atomic_dec_return(&state->refcount) < 0);
2951 wait_event(state->remove_wait, !atomic_read(&state->refcount));
2952 state->uart_port = NULL;
2953 mutex_unlock(&port->mutex);
2954out:
2955 mutex_unlock(&port_mutex);
2956
2957 return ret;
2958}
2959
2960/*
2961 * Are the two ports equivalent?
2962 */
2963int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2964{
2965 if (port1->iotype != port2->iotype)
2966 return 0;
2967
2968 switch (port1->iotype) {
2969 case UPIO_PORT:
2970 return (port1->iobase == port2->iobase);
2971 case UPIO_HUB6:
2972 return (port1->iobase == port2->iobase) &&
2973 (port1->hub6 == port2->hub6);
2974 case UPIO_MEM:
2975 case UPIO_MEM16:
2976 case UPIO_MEM32:
2977 case UPIO_MEM32BE:
2978 case UPIO_AU:
2979 case UPIO_TSI:
2980 return (port1->mapbase == port2->mapbase);
2981 }
2982 return 0;
2983}
2984EXPORT_SYMBOL(uart_match_port);
2985
2986/**
2987 * uart_handle_dcd_change - handle a change of carrier detect state
2988 * @uport: uart_port structure for the open port
2989 * @status: new carrier detect status, nonzero if active
2990 *
2991 * Caller must hold uport->lock
2992 */
2993void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2994{
2995 struct tty_port *port = &uport->state->port;
2996 struct tty_struct *tty = port->tty;
2997 struct tty_ldisc *ld;
2998
2999 lockdep_assert_held_once(&uport->lock);
3000
3001 if (tty) {
3002 ld = tty_ldisc_ref(tty);
3003 if (ld) {
3004 if (ld->ops->dcd_change)
3005 ld->ops->dcd_change(tty, status);
3006 tty_ldisc_deref(ld);
3007 }
3008 }
3009
3010 uport->icount.dcd++;
3011
3012 if (uart_dcd_enabled(uport)) {
3013 if (status)
3014 wake_up_interruptible(&port->open_wait);
3015 else if (tty)
3016 tty_hangup(tty);
3017 }
3018}
3019EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
3020
3021/**
3022 * uart_handle_cts_change - handle a change of clear-to-send state
3023 * @uport: uart_port structure for the open port
3024 * @status: new clear to send status, nonzero if active
3025 *
3026 * Caller must hold uport->lock
3027 */
3028void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
3029{
3030 lockdep_assert_held_once(&uport->lock);
3031
3032 uport->icount.cts++;
3033
3034 if (uart_softcts_mode(uport)) {
3035 if (uport->hw_stopped) {
3036 if (status) {
3037 uport->hw_stopped = 0;
3038 uport->ops->start_tx(uport);
3039 uart_write_wakeup(uport);
3040 }
3041 } else {
3042 if (!status) {
3043 uport->hw_stopped = 1;
3044 uport->ops->stop_tx(uport);
3045 }
3046 }
3047
3048 }
3049}
3050EXPORT_SYMBOL_GPL(uart_handle_cts_change);
3051
3052/**
3053 * uart_insert_char - push a char to the uart layer
3054 *
3055 * User is responsible to call tty_flip_buffer_push when they are done with
3056 * insertion.
3057 *
3058 * @port: corresponding port
3059 * @status: state of the serial port RX buffer (LSR for 8250)
3060 * @overrun: mask of overrun bits in @status
3061 * @ch: character to push
3062 * @flag: flag for the character (see TTY_NORMAL and friends)
3063 */
3064void uart_insert_char(struct uart_port *port, unsigned int status,
3065 unsigned int overrun, unsigned int ch, unsigned int flag)
3066{
3067 struct tty_port *tport = &port->state->port;
3068
3069 if ((status & port->ignore_status_mask & ~overrun) == 0)
3070 if (tty_insert_flip_char(tport, ch, flag) == 0)
3071 ++port->icount.buf_overrun;
3072
3073 /*
3074 * Overrun is special. Since it's reported immediately,
3075 * it doesn't affect the current character.
3076 */
3077 if (status & ~port->ignore_status_mask & overrun)
3078 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
3079 ++port->icount.buf_overrun;
3080}
3081EXPORT_SYMBOL_GPL(uart_insert_char);
3082
3083EXPORT_SYMBOL(uart_write_wakeup);
3084EXPORT_SYMBOL(uart_register_driver);
3085EXPORT_SYMBOL(uart_unregister_driver);
3086EXPORT_SYMBOL(uart_suspend_port);
3087EXPORT_SYMBOL(uart_resume_port);
3088EXPORT_SYMBOL(uart_add_one_port);
3089EXPORT_SYMBOL(uart_remove_one_port);
3090
3091/**
3092 * uart_get_rs485_mode() - retrieve rs485 properties for given uart
3093 * @dev: uart device
3094 * @rs485conf: output parameter
3095 *
3096 * This function implements the device tree binding described in
3097 * Documentation/devicetree/bindings/serial/rs485.txt.
3098 */
3099void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf)
3100{
3101 u32 rs485_delay[2];
3102 int ret;
3103
3104 ret = device_property_read_u32_array(dev, "rs485-rts-delay",
3105 rs485_delay, 2);
3106 if (!ret) {
3107 rs485conf->delay_rts_before_send = rs485_delay[0];
3108 rs485conf->delay_rts_after_send = rs485_delay[1];
3109 } else {
3110 rs485conf->delay_rts_before_send = 0;
3111 rs485conf->delay_rts_after_send = 0;
3112 }
3113
3114 /*
3115 * Clear full-duplex and enabled flags, set RTS polarity to active high
3116 * to get to a defined state with the following properties:
3117 */
3118 rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED |
3119 SER_RS485_RTS_AFTER_SEND);
3120 rs485conf->flags |= SER_RS485_RTS_ON_SEND;
3121
3122 if (device_property_read_bool(dev, "rs485-rx-during-tx"))
3123 rs485conf->flags |= SER_RS485_RX_DURING_TX;
3124
3125 if (device_property_read_bool(dev, "linux,rs485-enabled-at-boot-time"))
3126 rs485conf->flags |= SER_RS485_ENABLED;
3127
3128 if (device_property_read_bool(dev, "rs485-rts-active-low")) {
3129 rs485conf->flags &= ~SER_RS485_RTS_ON_SEND;
3130 rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
3131 }
3132}
3133EXPORT_SYMBOL_GPL(uart_get_rs485_mode);
3134
3135MODULE_DESCRIPTION("Serial driver core");
3136MODULE_LICENSE("GPL");
1/*
2 * Driver core for serial ports
3 *
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
5 *
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 */
23#include <linux/module.h>
24#include <linux/tty.h>
25#include <linux/tty_flip.h>
26#include <linux/slab.h>
27#include <linux/init.h>
28#include <linux/console.h>
29#include <linux/proc_fs.h>
30#include <linux/seq_file.h>
31#include <linux/device.h>
32#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
33#include <linux/serial_core.h>
34#include <linux/delay.h>
35#include <linux/mutex.h>
36
37#include <asm/irq.h>
38#include <asm/uaccess.h>
39
40/*
41 * This is used to lock changes in serial line configuration.
42 */
43static DEFINE_MUTEX(port_mutex);
44
45/*
46 * lockdep: port->lock is initialized in two places, but we
47 * want only one lock-class:
48 */
49static struct lock_class_key port_lock_key;
50
51#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
52
53#ifdef CONFIG_SERIAL_CORE_CONSOLE
54#define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
55#else
56#define uart_console(port) (0)
57#endif
58
59static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
60 struct ktermios *old_termios);
61static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
62static void uart_change_pm(struct uart_state *state, int pm_state);
63
64static void uart_port_shutdown(struct tty_port *port);
65
66/*
67 * This routine is used by the interrupt handler to schedule processing in
68 * the software interrupt portion of the driver.
69 */
70void uart_write_wakeup(struct uart_port *port)
71{
72 struct uart_state *state = port->state;
73 /*
74 * This means you called this function _after_ the port was
75 * closed. No cookie for you.
76 */
77 BUG_ON(!state);
78 tty_wakeup(state->port.tty);
79}
80
81static void uart_stop(struct tty_struct *tty)
82{
83 struct uart_state *state = tty->driver_data;
84 struct uart_port *port = state->uart_port;
85 unsigned long flags;
86
87 spin_lock_irqsave(&port->lock, flags);
88 port->ops->stop_tx(port);
89 spin_unlock_irqrestore(&port->lock, flags);
90}
91
92static void __uart_start(struct tty_struct *tty)
93{
94 struct uart_state *state = tty->driver_data;
95 struct uart_port *port = state->uart_port;
96
97 if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
98 !tty->stopped && !tty->hw_stopped)
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 inline 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 struct tty_port *port = &state->port;
139 unsigned long page;
140 int retval = 0;
141
142 if (uport->type == PORT_UNKNOWN)
143 return 1;
144
145 /*
146 * Initialise and allocate the transmit and temporary
147 * buffer.
148 */
149 if (!state->xmit.buf) {
150 /* This is protected by the per port mutex */
151 page = get_zeroed_page(GFP_KERNEL);
152 if (!page)
153 return -ENOMEM;
154
155 state->xmit.buf = (unsigned char *) page;
156 uart_circ_clear(&state->xmit);
157 }
158
159 retval = uport->ops->startup(uport);
160 if (retval == 0) {
161 if (uart_console(uport) && uport->cons->cflag) {
162 tty->termios->c_cflag = uport->cons->cflag;
163 uport->cons->cflag = 0;
164 }
165 /*
166 * Initialise the hardware port settings.
167 */
168 uart_change_speed(tty, state, NULL);
169
170 if (init_hw) {
171 /*
172 * Setup the RTS and DTR signals once the
173 * port is open and ready to respond.
174 */
175 if (tty->termios->c_cflag & CBAUD)
176 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
177 }
178
179 if (port->flags & ASYNC_CTS_FLOW) {
180 spin_lock_irq(&uport->lock);
181 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
182 tty->hw_stopped = 1;
183 spin_unlock_irq(&uport->lock);
184 }
185 }
186
187 /*
188 * This is to allow setserial on this port. People may want to set
189 * port/irq/type and then reconfigure the port properly if it failed
190 * now.
191 */
192 if (retval && capable(CAP_SYS_ADMIN))
193 return 1;
194
195 return retval;
196}
197
198static int uart_startup(struct tty_struct *tty, struct uart_state *state,
199 int init_hw)
200{
201 struct tty_port *port = &state->port;
202 int retval;
203
204 if (port->flags & ASYNC_INITIALIZED)
205 return 0;
206
207 /*
208 * Set the TTY IO error marker - we will only clear this
209 * once we have successfully opened the port.
210 */
211 set_bit(TTY_IO_ERROR, &tty->flags);
212
213 retval = uart_port_startup(tty, state, init_hw);
214 if (!retval) {
215 set_bit(ASYNCB_INITIALIZED, &port->flags);
216 clear_bit(TTY_IO_ERROR, &tty->flags);
217 } else if (retval > 0)
218 retval = 0;
219
220 return retval;
221}
222
223/*
224 * This routine will shutdown a serial port; interrupts are disabled, and
225 * DTR is dropped if the hangup on close termio flag is on. Calls to
226 * uart_shutdown are serialised by the per-port semaphore.
227 */
228static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
229{
230 struct uart_port *uport = state->uart_port;
231 struct tty_port *port = &state->port;
232
233 /*
234 * Set the TTY IO error marker
235 */
236 if (tty)
237 set_bit(TTY_IO_ERROR, &tty->flags);
238
239 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
240 /*
241 * Turn off DTR and RTS early.
242 */
243 if (!tty || (tty->termios->c_cflag & HUPCL))
244 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
245
246 uart_port_shutdown(port);
247 }
248
249 /*
250 * It's possible for shutdown to be called after suspend if we get
251 * a DCD drop (hangup) at just the right time. Clear suspended bit so
252 * we don't try to resume a port that has been shutdown.
253 */
254 clear_bit(ASYNCB_SUSPENDED, &port->flags);
255
256 /*
257 * Free the transmit buffer page.
258 */
259 if (state->xmit.buf) {
260 free_page((unsigned long)state->xmit.buf);
261 state->xmit.buf = NULL;
262 }
263}
264
265/**
266 * uart_update_timeout - update per-port FIFO timeout.
267 * @port: uart_port structure describing the port
268 * @cflag: termios cflag value
269 * @baud: speed of the port
270 *
271 * Set the port FIFO timeout value. The @cflag value should
272 * reflect the actual hardware settings.
273 */
274void
275uart_update_timeout(struct uart_port *port, unsigned int cflag,
276 unsigned int baud)
277{
278 unsigned int bits;
279
280 /* byte size and parity */
281 switch (cflag & CSIZE) {
282 case CS5:
283 bits = 7;
284 break;
285 case CS6:
286 bits = 8;
287 break;
288 case CS7:
289 bits = 9;
290 break;
291 default:
292 bits = 10;
293 break; /* CS8 */
294 }
295
296 if (cflag & CSTOPB)
297 bits++;
298 if (cflag & PARENB)
299 bits++;
300
301 /*
302 * The total number of bits to be transmitted in the fifo.
303 */
304 bits = bits * port->fifosize;
305
306 /*
307 * Figure the timeout to send the above number of bits.
308 * Add .02 seconds of slop
309 */
310 port->timeout = (HZ * bits) / baud + HZ/50;
311}
312
313EXPORT_SYMBOL(uart_update_timeout);
314
315/**
316 * uart_get_baud_rate - return baud rate for a particular port
317 * @port: uart_port structure describing the port in question.
318 * @termios: desired termios settings.
319 * @old: old termios (or NULL)
320 * @min: minimum acceptable baud rate
321 * @max: maximum acceptable baud rate
322 *
323 * Decode the termios structure into a numeric baud rate,
324 * taking account of the magic 38400 baud rate (with spd_*
325 * flags), and mapping the %B0 rate to 9600 baud.
326 *
327 * If the new baud rate is invalid, try the old termios setting.
328 * If it's still invalid, we try 9600 baud.
329 *
330 * Update the @termios structure to reflect the baud rate
331 * we're actually going to be using. Don't do this for the case
332 * where B0 is requested ("hang up").
333 */
334unsigned int
335uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
336 struct ktermios *old, unsigned int min, unsigned int max)
337{
338 unsigned int try, baud, altbaud = 38400;
339 int hung_up = 0;
340 upf_t flags = port->flags & UPF_SPD_MASK;
341
342 if (flags == UPF_SPD_HI)
343 altbaud = 57600;
344 else if (flags == UPF_SPD_VHI)
345 altbaud = 115200;
346 else if (flags == UPF_SPD_SHI)
347 altbaud = 230400;
348 else if (flags == UPF_SPD_WARP)
349 altbaud = 460800;
350
351 for (try = 0; try < 2; try++) {
352 baud = tty_termios_baud_rate(termios);
353
354 /*
355 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
356 * Die! Die! Die!
357 */
358 if (baud == 38400)
359 baud = altbaud;
360
361 /*
362 * Special case: B0 rate.
363 */
364 if (baud == 0) {
365 hung_up = 1;
366 baud = 9600;
367 }
368
369 if (baud >= min && baud <= max)
370 return baud;
371
372 /*
373 * Oops, the quotient was zero. Try again with
374 * the old baud rate if possible.
375 */
376 termios->c_cflag &= ~CBAUD;
377 if (old) {
378 baud = tty_termios_baud_rate(old);
379 if (!hung_up)
380 tty_termios_encode_baud_rate(termios,
381 baud, baud);
382 old = NULL;
383 continue;
384 }
385
386 /*
387 * As a last resort, if the range cannot be met then clip to
388 * the nearest chip supported rate.
389 */
390 if (!hung_up) {
391 if (baud <= min)
392 tty_termios_encode_baud_rate(termios,
393 min + 1, min + 1);
394 else
395 tty_termios_encode_baud_rate(termios,
396 max - 1, max - 1);
397 }
398 }
399 /* Should never happen */
400 WARN_ON(1);
401 return 0;
402}
403
404EXPORT_SYMBOL(uart_get_baud_rate);
405
406/**
407 * uart_get_divisor - return uart clock divisor
408 * @port: uart_port structure describing the port.
409 * @baud: desired baud rate
410 *
411 * Calculate the uart clock divisor for the port.
412 */
413unsigned int
414uart_get_divisor(struct uart_port *port, unsigned int baud)
415{
416 unsigned int quot;
417
418 /*
419 * Old custom speed handling.
420 */
421 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
422 quot = port->custom_divisor;
423 else
424 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
425
426 return quot;
427}
428
429EXPORT_SYMBOL(uart_get_divisor);
430
431/* FIXME: Consistent locking policy */
432static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
433 struct ktermios *old_termios)
434{
435 struct tty_port *port = &state->port;
436 struct uart_port *uport = state->uart_port;
437 struct ktermios *termios;
438
439 /*
440 * If we have no tty, termios, or the port does not exist,
441 * then we can't set the parameters for this port.
442 */
443 if (!tty || !tty->termios || uport->type == PORT_UNKNOWN)
444 return;
445
446 termios = tty->termios;
447
448 /*
449 * Set flags based on termios cflag
450 */
451 if (termios->c_cflag & CRTSCTS)
452 set_bit(ASYNCB_CTS_FLOW, &port->flags);
453 else
454 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
455
456 if (termios->c_cflag & CLOCAL)
457 clear_bit(ASYNCB_CHECK_CD, &port->flags);
458 else
459 set_bit(ASYNCB_CHECK_CD, &port->flags);
460
461 uport->ops->set_termios(uport, termios, old_termios);
462}
463
464static inline int __uart_put_char(struct uart_port *port,
465 struct circ_buf *circ, unsigned char c)
466{
467 unsigned long flags;
468 int ret = 0;
469
470 if (!circ->buf)
471 return 0;
472
473 spin_lock_irqsave(&port->lock, flags);
474 if (uart_circ_chars_free(circ) != 0) {
475 circ->buf[circ->head] = c;
476 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
477 ret = 1;
478 }
479 spin_unlock_irqrestore(&port->lock, flags);
480 return ret;
481}
482
483static int uart_put_char(struct tty_struct *tty, unsigned char ch)
484{
485 struct uart_state *state = tty->driver_data;
486
487 return __uart_put_char(state->uart_port, &state->xmit, ch);
488}
489
490static void uart_flush_chars(struct tty_struct *tty)
491{
492 uart_start(tty);
493}
494
495static int uart_write(struct tty_struct *tty,
496 const unsigned char *buf, int count)
497{
498 struct uart_state *state = tty->driver_data;
499 struct uart_port *port;
500 struct circ_buf *circ;
501 unsigned long flags;
502 int c, ret = 0;
503
504 /*
505 * This means you called this function _after_ the port was
506 * closed. No cookie for you.
507 */
508 if (!state) {
509 WARN_ON(1);
510 return -EL3HLT;
511 }
512
513 port = state->uart_port;
514 circ = &state->xmit;
515
516 if (!circ->buf)
517 return 0;
518
519 spin_lock_irqsave(&port->lock, flags);
520 while (1) {
521 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
522 if (count < c)
523 c = count;
524 if (c <= 0)
525 break;
526 memcpy(circ->buf + circ->head, buf, c);
527 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
528 buf += c;
529 count -= c;
530 ret += c;
531 }
532 spin_unlock_irqrestore(&port->lock, flags);
533
534 uart_start(tty);
535 return ret;
536}
537
538static int uart_write_room(struct tty_struct *tty)
539{
540 struct uart_state *state = tty->driver_data;
541 unsigned long flags;
542 int ret;
543
544 spin_lock_irqsave(&state->uart_port->lock, flags);
545 ret = uart_circ_chars_free(&state->xmit);
546 spin_unlock_irqrestore(&state->uart_port->lock, flags);
547 return ret;
548}
549
550static int uart_chars_in_buffer(struct tty_struct *tty)
551{
552 struct uart_state *state = tty->driver_data;
553 unsigned long flags;
554 int ret;
555
556 spin_lock_irqsave(&state->uart_port->lock, flags);
557 ret = uart_circ_chars_pending(&state->xmit);
558 spin_unlock_irqrestore(&state->uart_port->lock, flags);
559 return ret;
560}
561
562static void uart_flush_buffer(struct tty_struct *tty)
563{
564 struct uart_state *state = tty->driver_data;
565 struct uart_port *port;
566 unsigned long flags;
567
568 /*
569 * This means you called this function _after_ the port was
570 * closed. No cookie for you.
571 */
572 if (!state) {
573 WARN_ON(1);
574 return;
575 }
576
577 port = state->uart_port;
578 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
579
580 spin_lock_irqsave(&port->lock, flags);
581 uart_circ_clear(&state->xmit);
582 if (port->ops->flush_buffer)
583 port->ops->flush_buffer(port);
584 spin_unlock_irqrestore(&port->lock, flags);
585 tty_wakeup(tty);
586}
587
588/*
589 * This function is used to send a high-priority XON/XOFF character to
590 * the device
591 */
592static void uart_send_xchar(struct tty_struct *tty, char ch)
593{
594 struct uart_state *state = tty->driver_data;
595 struct uart_port *port = state->uart_port;
596 unsigned long flags;
597
598 if (port->ops->send_xchar)
599 port->ops->send_xchar(port, ch);
600 else {
601 port->x_char = ch;
602 if (ch) {
603 spin_lock_irqsave(&port->lock, flags);
604 port->ops->start_tx(port);
605 spin_unlock_irqrestore(&port->lock, flags);
606 }
607 }
608}
609
610static void uart_throttle(struct tty_struct *tty)
611{
612 struct uart_state *state = tty->driver_data;
613
614 if (I_IXOFF(tty))
615 uart_send_xchar(tty, STOP_CHAR(tty));
616
617 if (tty->termios->c_cflag & CRTSCTS)
618 uart_clear_mctrl(state->uart_port, TIOCM_RTS);
619}
620
621static void uart_unthrottle(struct tty_struct *tty)
622{
623 struct uart_state *state = tty->driver_data;
624 struct uart_port *port = state->uart_port;
625
626 if (I_IXOFF(tty)) {
627 if (port->x_char)
628 port->x_char = 0;
629 else
630 uart_send_xchar(tty, START_CHAR(tty));
631 }
632
633 if (tty->termios->c_cflag & CRTSCTS)
634 uart_set_mctrl(port, TIOCM_RTS);
635}
636
637static int uart_get_info(struct uart_state *state,
638 struct serial_struct __user *retinfo)
639{
640 struct uart_port *uport = state->uart_port;
641 struct tty_port *port = &state->port;
642 struct serial_struct tmp;
643
644 memset(&tmp, 0, sizeof(tmp));
645
646 /* Ensure the state we copy is consistent and no hardware changes
647 occur as we go */
648 mutex_lock(&port->mutex);
649
650 tmp.type = uport->type;
651 tmp.line = uport->line;
652 tmp.port = uport->iobase;
653 if (HIGH_BITS_OFFSET)
654 tmp.port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
655 tmp.irq = uport->irq;
656 tmp.flags = uport->flags;
657 tmp.xmit_fifo_size = uport->fifosize;
658 tmp.baud_base = uport->uartclk / 16;
659 tmp.close_delay = jiffies_to_msecs(port->close_delay) / 10;
660 tmp.closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
661 ASYNC_CLOSING_WAIT_NONE :
662 jiffies_to_msecs(port->closing_wait) / 10;
663 tmp.custom_divisor = uport->custom_divisor;
664 tmp.hub6 = uport->hub6;
665 tmp.io_type = uport->iotype;
666 tmp.iomem_reg_shift = uport->regshift;
667 tmp.iomem_base = (void *)(unsigned long)uport->mapbase;
668
669 mutex_unlock(&port->mutex);
670
671 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
672 return -EFAULT;
673 return 0;
674}
675
676static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
677 struct serial_struct __user *newinfo)
678{
679 struct serial_struct new_serial;
680 struct uart_port *uport = state->uart_port;
681 struct tty_port *port = &state->port;
682 unsigned long new_port;
683 unsigned int change_irq, change_port, closing_wait;
684 unsigned int old_custom_divisor, close_delay;
685 upf_t old_flags, new_flags;
686 int retval = 0;
687
688 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
689 return -EFAULT;
690
691 new_port = new_serial.port;
692 if (HIGH_BITS_OFFSET)
693 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
694
695 new_serial.irq = irq_canonicalize(new_serial.irq);
696 close_delay = msecs_to_jiffies(new_serial.close_delay * 10);
697 closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
698 ASYNC_CLOSING_WAIT_NONE :
699 msecs_to_jiffies(new_serial.closing_wait * 10);
700
701 /*
702 * This semaphore protects port->count. It is also
703 * very useful to prevent opens. Also, take the
704 * port configuration semaphore to make sure that a
705 * module insertion/removal doesn't change anything
706 * under us.
707 */
708 mutex_lock(&port->mutex);
709
710 change_irq = !(uport->flags & UPF_FIXED_PORT)
711 && new_serial.irq != uport->irq;
712
713 /*
714 * Since changing the 'type' of the port changes its resource
715 * allocations, we should treat type changes the same as
716 * IO port changes.
717 */
718 change_port = !(uport->flags & UPF_FIXED_PORT)
719 && (new_port != uport->iobase ||
720 (unsigned long)new_serial.iomem_base != uport->mapbase ||
721 new_serial.hub6 != uport->hub6 ||
722 new_serial.io_type != uport->iotype ||
723 new_serial.iomem_reg_shift != uport->regshift ||
724 new_serial.type != uport->type);
725
726 old_flags = uport->flags;
727 new_flags = new_serial.flags;
728 old_custom_divisor = uport->custom_divisor;
729
730 if (!capable(CAP_SYS_ADMIN)) {
731 retval = -EPERM;
732 if (change_irq || change_port ||
733 (new_serial.baud_base != uport->uartclk / 16) ||
734 (close_delay != port->close_delay) ||
735 (closing_wait != port->closing_wait) ||
736 (new_serial.xmit_fifo_size &&
737 new_serial.xmit_fifo_size != uport->fifosize) ||
738 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
739 goto exit;
740 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
741 (new_flags & UPF_USR_MASK));
742 uport->custom_divisor = new_serial.custom_divisor;
743 goto check_and_exit;
744 }
745
746 /*
747 * Ask the low level driver to verify the settings.
748 */
749 if (uport->ops->verify_port)
750 retval = uport->ops->verify_port(uport, &new_serial);
751
752 if ((new_serial.irq >= nr_irqs) || (new_serial.irq < 0) ||
753 (new_serial.baud_base < 9600))
754 retval = -EINVAL;
755
756 if (retval)
757 goto exit;
758
759 if (change_port || change_irq) {
760 retval = -EBUSY;
761
762 /*
763 * Make sure that we are the sole user of this port.
764 */
765 if (tty_port_users(port) > 1)
766 goto exit;
767
768 /*
769 * We need to shutdown the serial port at the old
770 * port/type/irq combination.
771 */
772 uart_shutdown(tty, state);
773 }
774
775 if (change_port) {
776 unsigned long old_iobase, old_mapbase;
777 unsigned int old_type, old_iotype, old_hub6, old_shift;
778
779 old_iobase = uport->iobase;
780 old_mapbase = uport->mapbase;
781 old_type = uport->type;
782 old_hub6 = uport->hub6;
783 old_iotype = uport->iotype;
784 old_shift = uport->regshift;
785
786 /*
787 * Free and release old regions
788 */
789 if (old_type != PORT_UNKNOWN)
790 uport->ops->release_port(uport);
791
792 uport->iobase = new_port;
793 uport->type = new_serial.type;
794 uport->hub6 = new_serial.hub6;
795 uport->iotype = new_serial.io_type;
796 uport->regshift = new_serial.iomem_reg_shift;
797 uport->mapbase = (unsigned long)new_serial.iomem_base;
798
799 /*
800 * Claim and map the new regions
801 */
802 if (uport->type != PORT_UNKNOWN) {
803 retval = uport->ops->request_port(uport);
804 } else {
805 /* Always success - Jean II */
806 retval = 0;
807 }
808
809 /*
810 * If we fail to request resources for the
811 * new port, try to restore the old settings.
812 */
813 if (retval && old_type != PORT_UNKNOWN) {
814 uport->iobase = old_iobase;
815 uport->type = old_type;
816 uport->hub6 = old_hub6;
817 uport->iotype = old_iotype;
818 uport->regshift = old_shift;
819 uport->mapbase = old_mapbase;
820 retval = uport->ops->request_port(uport);
821 /*
822 * If we failed to restore the old settings,
823 * we fail like this.
824 */
825 if (retval)
826 uport->type = PORT_UNKNOWN;
827
828 /*
829 * We failed anyway.
830 */
831 retval = -EBUSY;
832 /* Added to return the correct error -Ram Gupta */
833 goto exit;
834 }
835 }
836
837 if (change_irq)
838 uport->irq = new_serial.irq;
839 if (!(uport->flags & UPF_FIXED_PORT))
840 uport->uartclk = new_serial.baud_base * 16;
841 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
842 (new_flags & UPF_CHANGE_MASK);
843 uport->custom_divisor = new_serial.custom_divisor;
844 port->close_delay = close_delay;
845 port->closing_wait = closing_wait;
846 if (new_serial.xmit_fifo_size)
847 uport->fifosize = new_serial.xmit_fifo_size;
848 if (port->tty)
849 port->tty->low_latency =
850 (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
851
852 check_and_exit:
853 retval = 0;
854 if (uport->type == PORT_UNKNOWN)
855 goto exit;
856 if (port->flags & ASYNC_INITIALIZED) {
857 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
858 old_custom_divisor != uport->custom_divisor) {
859 /*
860 * If they're setting up a custom divisor or speed,
861 * instead of clearing it, then bitch about it. No
862 * need to rate-limit; it's CAP_SYS_ADMIN only.
863 */
864 if (uport->flags & UPF_SPD_MASK) {
865 char buf[64];
866 printk(KERN_NOTICE
867 "%s sets custom speed on %s. This "
868 "is deprecated.\n", current->comm,
869 tty_name(port->tty, buf));
870 }
871 uart_change_speed(tty, state, NULL);
872 }
873 } else
874 retval = uart_startup(tty, state, 1);
875 exit:
876 mutex_unlock(&port->mutex);
877 return retval;
878}
879
880/**
881 * uart_get_lsr_info - get line status register info
882 * @tty: tty associated with the UART
883 * @state: UART being queried
884 * @value: returned modem value
885 *
886 * Note: uart_ioctl protects us against hangups.
887 */
888static int uart_get_lsr_info(struct tty_struct *tty,
889 struct uart_state *state, unsigned int __user *value)
890{
891 struct uart_port *uport = state->uart_port;
892 unsigned int result;
893
894 result = uport->ops->tx_empty(uport);
895
896 /*
897 * If we're about to load something into the transmit
898 * register, we'll pretend the transmitter isn't empty to
899 * avoid a race condition (depending on when the transmit
900 * interrupt happens).
901 */
902 if (uport->x_char ||
903 ((uart_circ_chars_pending(&state->xmit) > 0) &&
904 !tty->stopped && !tty->hw_stopped))
905 result &= ~TIOCSER_TEMT;
906
907 return put_user(result, value);
908}
909
910static int uart_tiocmget(struct tty_struct *tty)
911{
912 struct uart_state *state = tty->driver_data;
913 struct tty_port *port = &state->port;
914 struct uart_port *uport = state->uart_port;
915 int result = -EIO;
916
917 mutex_lock(&port->mutex);
918 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
919 result = uport->mctrl;
920 spin_lock_irq(&uport->lock);
921 result |= uport->ops->get_mctrl(uport);
922 spin_unlock_irq(&uport->lock);
923 }
924 mutex_unlock(&port->mutex);
925
926 return result;
927}
928
929static int
930uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
931{
932 struct uart_state *state = tty->driver_data;
933 struct uart_port *uport = state->uart_port;
934 struct tty_port *port = &state->port;
935 int ret = -EIO;
936
937 mutex_lock(&port->mutex);
938 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
939 uart_update_mctrl(uport, set, clear);
940 ret = 0;
941 }
942 mutex_unlock(&port->mutex);
943 return ret;
944}
945
946static int uart_break_ctl(struct tty_struct *tty, int break_state)
947{
948 struct uart_state *state = tty->driver_data;
949 struct tty_port *port = &state->port;
950 struct uart_port *uport = state->uart_port;
951
952 mutex_lock(&port->mutex);
953
954 if (uport->type != PORT_UNKNOWN)
955 uport->ops->break_ctl(uport, break_state);
956
957 mutex_unlock(&port->mutex);
958 return 0;
959}
960
961static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
962{
963 struct uart_port *uport = state->uart_port;
964 struct tty_port *port = &state->port;
965 int flags, ret;
966
967 if (!capable(CAP_SYS_ADMIN))
968 return -EPERM;
969
970 /*
971 * Take the per-port semaphore. This prevents count from
972 * changing, and hence any extra opens of the port while
973 * we're auto-configuring.
974 */
975 if (mutex_lock_interruptible(&port->mutex))
976 return -ERESTARTSYS;
977
978 ret = -EBUSY;
979 if (tty_port_users(port) == 1) {
980 uart_shutdown(tty, state);
981
982 /*
983 * If we already have a port type configured,
984 * we must release its resources.
985 */
986 if (uport->type != PORT_UNKNOWN)
987 uport->ops->release_port(uport);
988
989 flags = UART_CONFIG_TYPE;
990 if (uport->flags & UPF_AUTO_IRQ)
991 flags |= UART_CONFIG_IRQ;
992
993 /*
994 * This will claim the ports resources if
995 * a port is found.
996 */
997 uport->ops->config_port(uport, flags);
998
999 ret = uart_startup(tty, state, 1);
1000 }
1001 mutex_unlock(&port->mutex);
1002 return ret;
1003}
1004
1005/*
1006 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1007 * - mask passed in arg for lines of interest
1008 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1009 * Caller should use TIOCGICOUNT to see which one it was
1010 *
1011 * FIXME: This wants extracting into a common all driver implementation
1012 * of TIOCMWAIT using tty_port.
1013 */
1014static int
1015uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1016{
1017 struct uart_port *uport = state->uart_port;
1018 struct tty_port *port = &state->port;
1019 DECLARE_WAITQUEUE(wait, current);
1020 struct uart_icount cprev, cnow;
1021 int ret;
1022
1023 /*
1024 * note the counters on entry
1025 */
1026 spin_lock_irq(&uport->lock);
1027 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1028
1029 /*
1030 * Force modem status interrupts on
1031 */
1032 uport->ops->enable_ms(uport);
1033 spin_unlock_irq(&uport->lock);
1034
1035 add_wait_queue(&port->delta_msr_wait, &wait);
1036 for (;;) {
1037 spin_lock_irq(&uport->lock);
1038 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1039 spin_unlock_irq(&uport->lock);
1040
1041 set_current_state(TASK_INTERRUPTIBLE);
1042
1043 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1044 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1045 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1046 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1047 ret = 0;
1048 break;
1049 }
1050
1051 schedule();
1052
1053 /* see if a signal did it */
1054 if (signal_pending(current)) {
1055 ret = -ERESTARTSYS;
1056 break;
1057 }
1058
1059 cprev = cnow;
1060 }
1061
1062 current->state = TASK_RUNNING;
1063 remove_wait_queue(&port->delta_msr_wait, &wait);
1064
1065 return ret;
1066}
1067
1068/*
1069 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1070 * Return: write counters to the user passed counter struct
1071 * NB: both 1->0 and 0->1 transitions are counted except for
1072 * RI where only 0->1 is counted.
1073 */
1074static int uart_get_icount(struct tty_struct *tty,
1075 struct serial_icounter_struct *icount)
1076{
1077 struct uart_state *state = tty->driver_data;
1078 struct uart_icount cnow;
1079 struct uart_port *uport = state->uart_port;
1080
1081 spin_lock_irq(&uport->lock);
1082 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1083 spin_unlock_irq(&uport->lock);
1084
1085 icount->cts = cnow.cts;
1086 icount->dsr = cnow.dsr;
1087 icount->rng = cnow.rng;
1088 icount->dcd = cnow.dcd;
1089 icount->rx = cnow.rx;
1090 icount->tx = cnow.tx;
1091 icount->frame = cnow.frame;
1092 icount->overrun = cnow.overrun;
1093 icount->parity = cnow.parity;
1094 icount->brk = cnow.brk;
1095 icount->buf_overrun = cnow.buf_overrun;
1096
1097 return 0;
1098}
1099
1100/*
1101 * Called via sys_ioctl. We can use spin_lock_irq() here.
1102 */
1103static int
1104uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1105 unsigned long arg)
1106{
1107 struct uart_state *state = tty->driver_data;
1108 struct tty_port *port = &state->port;
1109 void __user *uarg = (void __user *)arg;
1110 int ret = -ENOIOCTLCMD;
1111
1112
1113 /*
1114 * These ioctls don't rely on the hardware to be present.
1115 */
1116 switch (cmd) {
1117 case TIOCGSERIAL:
1118 ret = uart_get_info(state, uarg);
1119 break;
1120
1121 case TIOCSSERIAL:
1122 ret = uart_set_info(tty, state, uarg);
1123 break;
1124
1125 case TIOCSERCONFIG:
1126 ret = uart_do_autoconfig(tty, state);
1127 break;
1128
1129 case TIOCSERGWILD: /* obsolete */
1130 case TIOCSERSWILD: /* obsolete */
1131 ret = 0;
1132 break;
1133 }
1134
1135 if (ret != -ENOIOCTLCMD)
1136 goto out;
1137
1138 if (tty->flags & (1 << TTY_IO_ERROR)) {
1139 ret = -EIO;
1140 goto out;
1141 }
1142
1143 /*
1144 * The following should only be used when hardware is present.
1145 */
1146 switch (cmd) {
1147 case TIOCMIWAIT:
1148 ret = uart_wait_modem_status(state, arg);
1149 break;
1150 }
1151
1152 if (ret != -ENOIOCTLCMD)
1153 goto out;
1154
1155 mutex_lock(&port->mutex);
1156
1157 if (tty->flags & (1 << TTY_IO_ERROR)) {
1158 ret = -EIO;
1159 goto out_up;
1160 }
1161
1162 /*
1163 * All these rely on hardware being present and need to be
1164 * protected against the tty being hung up.
1165 */
1166 switch (cmd) {
1167 case TIOCSERGETLSR: /* Get line status register */
1168 ret = uart_get_lsr_info(tty, state, uarg);
1169 break;
1170
1171 default: {
1172 struct uart_port *uport = state->uart_port;
1173 if (uport->ops->ioctl)
1174 ret = uport->ops->ioctl(uport, cmd, arg);
1175 break;
1176 }
1177 }
1178out_up:
1179 mutex_unlock(&port->mutex);
1180out:
1181 return ret;
1182}
1183
1184static void uart_set_ldisc(struct tty_struct *tty)
1185{
1186 struct uart_state *state = tty->driver_data;
1187 struct uart_port *uport = state->uart_port;
1188
1189 if (uport->ops->set_ldisc)
1190 uport->ops->set_ldisc(uport, tty->termios->c_line);
1191}
1192
1193static void uart_set_termios(struct tty_struct *tty,
1194 struct ktermios *old_termios)
1195{
1196 struct uart_state *state = tty->driver_data;
1197 unsigned long flags;
1198 unsigned int cflag = tty->termios->c_cflag;
1199
1200
1201 /*
1202 * These are the bits that are used to setup various
1203 * flags in the low level driver. We can ignore the Bfoo
1204 * bits in c_cflag; c_[io]speed will always be set
1205 * appropriately by set_termios() in tty_ioctl.c
1206 */
1207#define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1208 if ((cflag ^ old_termios->c_cflag) == 0 &&
1209 tty->termios->c_ospeed == old_termios->c_ospeed &&
1210 tty->termios->c_ispeed == old_termios->c_ispeed &&
1211 RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) {
1212 return;
1213 }
1214
1215 uart_change_speed(tty, state, old_termios);
1216
1217 /* Handle transition to B0 status */
1218 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1219 uart_clear_mctrl(state->uart_port, TIOCM_RTS | TIOCM_DTR);
1220 /* Handle transition away from B0 status */
1221 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1222 unsigned int mask = TIOCM_DTR;
1223 if (!(cflag & CRTSCTS) ||
1224 !test_bit(TTY_THROTTLED, &tty->flags))
1225 mask |= TIOCM_RTS;
1226 uart_set_mctrl(state->uart_port, mask);
1227 }
1228
1229 /* Handle turning off CRTSCTS */
1230 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1231 spin_lock_irqsave(&state->uart_port->lock, flags);
1232 tty->hw_stopped = 0;
1233 __uart_start(tty);
1234 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1235 }
1236 /* Handle turning on CRTSCTS */
1237 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1238 spin_lock_irqsave(&state->uart_port->lock, flags);
1239 if (!(state->uart_port->ops->get_mctrl(state->uart_port) & TIOCM_CTS)) {
1240 tty->hw_stopped = 1;
1241 state->uart_port->ops->stop_tx(state->uart_port);
1242 }
1243 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1244 }
1245}
1246
1247/*
1248 * In 2.4.5, calls to this will be serialized via the BKL in
1249 * linux/drivers/char/tty_io.c:tty_release()
1250 * linux/drivers/char/tty_io.c:do_tty_handup()
1251 */
1252static void uart_close(struct tty_struct *tty, struct file *filp)
1253{
1254 struct uart_state *state = tty->driver_data;
1255 struct tty_port *port;
1256 struct uart_port *uport;
1257 unsigned long flags;
1258
1259 if (!state)
1260 return;
1261
1262 uport = state->uart_port;
1263 port = &state->port;
1264
1265 pr_debug("uart_close(%d) called\n", uport->line);
1266
1267 if (tty_port_close_start(port, tty, filp) == 0)
1268 return;
1269
1270 /*
1271 * At this point, we stop accepting input. To do this, we
1272 * disable the receive line status interrupts.
1273 */
1274 if (port->flags & ASYNC_INITIALIZED) {
1275 unsigned long flags;
1276 spin_lock_irqsave(&uport->lock, flags);
1277 uport->ops->stop_rx(uport);
1278 spin_unlock_irqrestore(&uport->lock, flags);
1279 /*
1280 * Before we drop DTR, make sure the UART transmitter
1281 * has completely drained; this is especially
1282 * important if there is a transmit FIFO!
1283 */
1284 uart_wait_until_sent(tty, uport->timeout);
1285 }
1286
1287 mutex_lock(&port->mutex);
1288 uart_shutdown(tty, state);
1289 uart_flush_buffer(tty);
1290
1291 tty_ldisc_flush(tty);
1292
1293 tty_port_tty_set(port, NULL);
1294 spin_lock_irqsave(&port->lock, flags);
1295 tty->closing = 0;
1296
1297 if (port->blocked_open) {
1298 spin_unlock_irqrestore(&port->lock, flags);
1299 if (port->close_delay)
1300 msleep_interruptible(
1301 jiffies_to_msecs(port->close_delay));
1302 spin_lock_irqsave(&port->lock, flags);
1303 } else if (!uart_console(uport)) {
1304 spin_unlock_irqrestore(&port->lock, flags);
1305 uart_change_pm(state, 3);
1306 spin_lock_irqsave(&port->lock, flags);
1307 }
1308
1309 /*
1310 * Wake up anyone trying to open this port.
1311 */
1312 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1313 clear_bit(ASYNCB_CLOSING, &port->flags);
1314 spin_unlock_irqrestore(&port->lock, flags);
1315 wake_up_interruptible(&port->open_wait);
1316 wake_up_interruptible(&port->close_wait);
1317
1318 mutex_unlock(&port->mutex);
1319}
1320
1321static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1322{
1323 struct uart_state *state = tty->driver_data;
1324 struct uart_port *port = state->uart_port;
1325 unsigned long char_time, expire;
1326
1327 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1328 return;
1329
1330 /*
1331 * Set the check interval to be 1/5 of the estimated time to
1332 * send a single character, and make it at least 1. The check
1333 * interval should also be less than the timeout.
1334 *
1335 * Note: we have to use pretty tight timings here to satisfy
1336 * the NIST-PCTS.
1337 */
1338 char_time = (port->timeout - HZ/50) / port->fifosize;
1339 char_time = char_time / 5;
1340 if (char_time == 0)
1341 char_time = 1;
1342 if (timeout && timeout < char_time)
1343 char_time = timeout;
1344
1345 /*
1346 * If the transmitter hasn't cleared in twice the approximate
1347 * amount of time to send the entire FIFO, it probably won't
1348 * ever clear. This assumes the UART isn't doing flow
1349 * control, which is currently the case. Hence, if it ever
1350 * takes longer than port->timeout, this is probably due to a
1351 * UART bug of some kind. So, we clamp the timeout parameter at
1352 * 2*port->timeout.
1353 */
1354 if (timeout == 0 || timeout > 2 * port->timeout)
1355 timeout = 2 * port->timeout;
1356
1357 expire = jiffies + timeout;
1358
1359 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1360 port->line, jiffies, expire);
1361
1362 /*
1363 * Check whether the transmitter is empty every 'char_time'.
1364 * 'timeout' / 'expire' give us the maximum amount of time
1365 * we wait.
1366 */
1367 while (!port->ops->tx_empty(port)) {
1368 msleep_interruptible(jiffies_to_msecs(char_time));
1369 if (signal_pending(current))
1370 break;
1371 if (time_after(jiffies, expire))
1372 break;
1373 }
1374}
1375
1376/*
1377 * This is called with the BKL held in
1378 * linux/drivers/char/tty_io.c:do_tty_hangup()
1379 * We're called from the eventd thread, so we can sleep for
1380 * a _short_ time only.
1381 */
1382static void uart_hangup(struct tty_struct *tty)
1383{
1384 struct uart_state *state = tty->driver_data;
1385 struct tty_port *port = &state->port;
1386 unsigned long flags;
1387
1388 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1389
1390 mutex_lock(&port->mutex);
1391 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1392 uart_flush_buffer(tty);
1393 uart_shutdown(tty, state);
1394 spin_lock_irqsave(&port->lock, flags);
1395 port->count = 0;
1396 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1397 spin_unlock_irqrestore(&port->lock, flags);
1398 tty_port_tty_set(port, NULL);
1399 wake_up_interruptible(&port->open_wait);
1400 wake_up_interruptible(&port->delta_msr_wait);
1401 }
1402 mutex_unlock(&port->mutex);
1403}
1404
1405static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1406{
1407 return 0;
1408}
1409
1410static void uart_port_shutdown(struct tty_port *port)
1411{
1412 struct uart_state *state = container_of(port, struct uart_state, port);
1413 struct uart_port *uport = state->uart_port;
1414
1415 /*
1416 * clear delta_msr_wait queue to avoid mem leaks: we may free
1417 * the irq here so the queue might never be woken up. Note
1418 * that we won't end up waiting on delta_msr_wait again since
1419 * any outstanding file descriptors should be pointing at
1420 * hung_up_tty_fops now.
1421 */
1422 wake_up_interruptible(&port->delta_msr_wait);
1423
1424 /*
1425 * Free the IRQ and disable the port.
1426 */
1427 uport->ops->shutdown(uport);
1428
1429 /*
1430 * Ensure that the IRQ handler isn't running on another CPU.
1431 */
1432 synchronize_irq(uport->irq);
1433}
1434
1435static int uart_carrier_raised(struct tty_port *port)
1436{
1437 struct uart_state *state = container_of(port, struct uart_state, port);
1438 struct uart_port *uport = state->uart_port;
1439 int mctrl;
1440 spin_lock_irq(&uport->lock);
1441 uport->ops->enable_ms(uport);
1442 mctrl = uport->ops->get_mctrl(uport);
1443 spin_unlock_irq(&uport->lock);
1444 if (mctrl & TIOCM_CAR)
1445 return 1;
1446 return 0;
1447}
1448
1449static void uart_dtr_rts(struct tty_port *port, int onoff)
1450{
1451 struct uart_state *state = container_of(port, struct uart_state, port);
1452 struct uart_port *uport = state->uart_port;
1453
1454 if (onoff)
1455 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1456 else
1457 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1458}
1459
1460/*
1461 * calls to uart_open are serialised by the BKL in
1462 * fs/char_dev.c:chrdev_open()
1463 * Note that if this fails, then uart_close() _will_ be called.
1464 *
1465 * In time, we want to scrap the "opening nonpresent ports"
1466 * behaviour and implement an alternative way for setserial
1467 * to set base addresses/ports/types. This will allow us to
1468 * get rid of a certain amount of extra tests.
1469 */
1470static int uart_open(struct tty_struct *tty, struct file *filp)
1471{
1472 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1473 int retval, line = tty->index;
1474 struct uart_state *state = drv->state + line;
1475 struct tty_port *port = &state->port;
1476
1477 pr_debug("uart_open(%d) called\n", line);
1478
1479 /*
1480 * We take the semaphore here to guarantee that we won't be re-entered
1481 * while allocating the state structure, or while we request any IRQs
1482 * that the driver may need. This also has the nice side-effect that
1483 * it delays the action of uart_hangup, so we can guarantee that
1484 * state->port.tty will always contain something reasonable.
1485 */
1486 if (mutex_lock_interruptible(&port->mutex)) {
1487 retval = -ERESTARTSYS;
1488 goto end;
1489 }
1490
1491 port->count++;
1492 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1493 retval = -ENXIO;
1494 goto err_dec_count;
1495 }
1496
1497 /*
1498 * Once we set tty->driver_data here, we are guaranteed that
1499 * uart_close() will decrement the driver module use count.
1500 * Any failures from here onwards should not touch the count.
1501 */
1502 tty->driver_data = state;
1503 state->uart_port->state = state;
1504 tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1505 tty_port_tty_set(port, tty);
1506
1507 /*
1508 * If the port is in the middle of closing, bail out now.
1509 */
1510 if (tty_hung_up_p(filp)) {
1511 retval = -EAGAIN;
1512 goto err_dec_count;
1513 }
1514
1515 /*
1516 * Make sure the device is in D0 state.
1517 */
1518 if (port->count == 1)
1519 uart_change_pm(state, 0);
1520
1521 /*
1522 * Start up the serial port.
1523 */
1524 retval = uart_startup(tty, state, 0);
1525
1526 /*
1527 * If we succeeded, wait until the port is ready.
1528 */
1529 mutex_unlock(&port->mutex);
1530 if (retval == 0)
1531 retval = tty_port_block_til_ready(port, tty, filp);
1532
1533end:
1534 return retval;
1535err_dec_count:
1536 port->count--;
1537 mutex_unlock(&port->mutex);
1538 goto end;
1539}
1540
1541static const char *uart_type(struct uart_port *port)
1542{
1543 const char *str = NULL;
1544
1545 if (port->ops->type)
1546 str = port->ops->type(port);
1547
1548 if (!str)
1549 str = "unknown";
1550
1551 return str;
1552}
1553
1554#ifdef CONFIG_PROC_FS
1555
1556static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1557{
1558 struct uart_state *state = drv->state + i;
1559 struct tty_port *port = &state->port;
1560 int pm_state;
1561 struct uart_port *uport = state->uart_port;
1562 char stat_buf[32];
1563 unsigned int status;
1564 int mmio;
1565
1566 if (!uport)
1567 return;
1568
1569 mmio = uport->iotype >= UPIO_MEM;
1570 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1571 uport->line, uart_type(uport),
1572 mmio ? "mmio:0x" : "port:",
1573 mmio ? (unsigned long long)uport->mapbase
1574 : (unsigned long long)uport->iobase,
1575 uport->irq);
1576
1577 if (uport->type == PORT_UNKNOWN) {
1578 seq_putc(m, '\n');
1579 return;
1580 }
1581
1582 if (capable(CAP_SYS_ADMIN)) {
1583 mutex_lock(&port->mutex);
1584 pm_state = state->pm_state;
1585 if (pm_state)
1586 uart_change_pm(state, 0);
1587 spin_lock_irq(&uport->lock);
1588 status = uport->ops->get_mctrl(uport);
1589 spin_unlock_irq(&uport->lock);
1590 if (pm_state)
1591 uart_change_pm(state, pm_state);
1592 mutex_unlock(&port->mutex);
1593
1594 seq_printf(m, " tx:%d rx:%d",
1595 uport->icount.tx, uport->icount.rx);
1596 if (uport->icount.frame)
1597 seq_printf(m, " fe:%d",
1598 uport->icount.frame);
1599 if (uport->icount.parity)
1600 seq_printf(m, " pe:%d",
1601 uport->icount.parity);
1602 if (uport->icount.brk)
1603 seq_printf(m, " brk:%d",
1604 uport->icount.brk);
1605 if (uport->icount.overrun)
1606 seq_printf(m, " oe:%d",
1607 uport->icount.overrun);
1608
1609#define INFOBIT(bit, str) \
1610 if (uport->mctrl & (bit)) \
1611 strncat(stat_buf, (str), sizeof(stat_buf) - \
1612 strlen(stat_buf) - 2)
1613#define STATBIT(bit, str) \
1614 if (status & (bit)) \
1615 strncat(stat_buf, (str), sizeof(stat_buf) - \
1616 strlen(stat_buf) - 2)
1617
1618 stat_buf[0] = '\0';
1619 stat_buf[1] = '\0';
1620 INFOBIT(TIOCM_RTS, "|RTS");
1621 STATBIT(TIOCM_CTS, "|CTS");
1622 INFOBIT(TIOCM_DTR, "|DTR");
1623 STATBIT(TIOCM_DSR, "|DSR");
1624 STATBIT(TIOCM_CAR, "|CD");
1625 STATBIT(TIOCM_RNG, "|RI");
1626 if (stat_buf[0])
1627 stat_buf[0] = ' ';
1628
1629 seq_puts(m, stat_buf);
1630 }
1631 seq_putc(m, '\n');
1632#undef STATBIT
1633#undef INFOBIT
1634}
1635
1636static int uart_proc_show(struct seq_file *m, void *v)
1637{
1638 struct tty_driver *ttydrv = m->private;
1639 struct uart_driver *drv = ttydrv->driver_state;
1640 int i;
1641
1642 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1643 "", "", "");
1644 for (i = 0; i < drv->nr; i++)
1645 uart_line_info(m, drv, i);
1646 return 0;
1647}
1648
1649static int uart_proc_open(struct inode *inode, struct file *file)
1650{
1651 return single_open(file, uart_proc_show, PDE(inode)->data);
1652}
1653
1654static const struct file_operations uart_proc_fops = {
1655 .owner = THIS_MODULE,
1656 .open = uart_proc_open,
1657 .read = seq_read,
1658 .llseek = seq_lseek,
1659 .release = single_release,
1660};
1661#endif
1662
1663#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1664/*
1665 * uart_console_write - write a console message to a serial port
1666 * @port: the port to write the message
1667 * @s: array of characters
1668 * @count: number of characters in string to write
1669 * @write: function to write character to port
1670 */
1671void uart_console_write(struct uart_port *port, const char *s,
1672 unsigned int count,
1673 void (*putchar)(struct uart_port *, int))
1674{
1675 unsigned int i;
1676
1677 for (i = 0; i < count; i++, s++) {
1678 if (*s == '\n')
1679 putchar(port, '\r');
1680 putchar(port, *s);
1681 }
1682}
1683EXPORT_SYMBOL_GPL(uart_console_write);
1684
1685/*
1686 * Check whether an invalid uart number has been specified, and
1687 * if so, search for the first available port that does have
1688 * console support.
1689 */
1690struct uart_port * __init
1691uart_get_console(struct uart_port *ports, int nr, struct console *co)
1692{
1693 int idx = co->index;
1694
1695 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1696 ports[idx].membase == NULL))
1697 for (idx = 0; idx < nr; idx++)
1698 if (ports[idx].iobase != 0 ||
1699 ports[idx].membase != NULL)
1700 break;
1701
1702 co->index = idx;
1703
1704 return ports + idx;
1705}
1706
1707/**
1708 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1709 * @options: pointer to option string
1710 * @baud: pointer to an 'int' variable for the baud rate.
1711 * @parity: pointer to an 'int' variable for the parity.
1712 * @bits: pointer to an 'int' variable for the number of data bits.
1713 * @flow: pointer to an 'int' variable for the flow control character.
1714 *
1715 * uart_parse_options decodes a string containing the serial console
1716 * options. The format of the string is <baud><parity><bits><flow>,
1717 * eg: 115200n8r
1718 */
1719void
1720uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1721{
1722 char *s = options;
1723
1724 *baud = simple_strtoul(s, NULL, 10);
1725 while (*s >= '0' && *s <= '9')
1726 s++;
1727 if (*s)
1728 *parity = *s++;
1729 if (*s)
1730 *bits = *s++ - '0';
1731 if (*s)
1732 *flow = *s;
1733}
1734EXPORT_SYMBOL_GPL(uart_parse_options);
1735
1736struct baud_rates {
1737 unsigned int rate;
1738 unsigned int cflag;
1739};
1740
1741static const struct baud_rates baud_rates[] = {
1742 { 921600, B921600 },
1743 { 460800, B460800 },
1744 { 230400, B230400 },
1745 { 115200, B115200 },
1746 { 57600, B57600 },
1747 { 38400, B38400 },
1748 { 19200, B19200 },
1749 { 9600, B9600 },
1750 { 4800, B4800 },
1751 { 2400, B2400 },
1752 { 1200, B1200 },
1753 { 0, B38400 }
1754};
1755
1756/**
1757 * uart_set_options - setup the serial console parameters
1758 * @port: pointer to the serial ports uart_port structure
1759 * @co: console pointer
1760 * @baud: baud rate
1761 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1762 * @bits: number of data bits
1763 * @flow: flow control character - 'r' (rts)
1764 */
1765int
1766uart_set_options(struct uart_port *port, struct console *co,
1767 int baud, int parity, int bits, int flow)
1768{
1769 struct ktermios termios;
1770 static struct ktermios dummy;
1771 int i;
1772
1773 /*
1774 * Ensure that the serial console lock is initialised
1775 * early.
1776 */
1777 spin_lock_init(&port->lock);
1778 lockdep_set_class(&port->lock, &port_lock_key);
1779
1780 memset(&termios, 0, sizeof(struct ktermios));
1781
1782 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1783
1784 /*
1785 * Construct a cflag setting.
1786 */
1787 for (i = 0; baud_rates[i].rate; i++)
1788 if (baud_rates[i].rate <= baud)
1789 break;
1790
1791 termios.c_cflag |= baud_rates[i].cflag;
1792
1793 if (bits == 7)
1794 termios.c_cflag |= CS7;
1795 else
1796 termios.c_cflag |= CS8;
1797
1798 switch (parity) {
1799 case 'o': case 'O':
1800 termios.c_cflag |= PARODD;
1801 /*fall through*/
1802 case 'e': case 'E':
1803 termios.c_cflag |= PARENB;
1804 break;
1805 }
1806
1807 if (flow == 'r')
1808 termios.c_cflag |= CRTSCTS;
1809
1810 /*
1811 * some uarts on other side don't support no flow control.
1812 * So we set * DTR in host uart to make them happy
1813 */
1814 port->mctrl |= TIOCM_DTR;
1815
1816 port->ops->set_termios(port, &termios, &dummy);
1817 /*
1818 * Allow the setting of the UART parameters with a NULL console
1819 * too:
1820 */
1821 if (co)
1822 co->cflag = termios.c_cflag;
1823
1824 return 0;
1825}
1826EXPORT_SYMBOL_GPL(uart_set_options);
1827#endif /* CONFIG_SERIAL_CORE_CONSOLE */
1828
1829/**
1830 * uart_change_pm - set power state of the port
1831 *
1832 * @state: port descriptor
1833 * @pm_state: new state
1834 *
1835 * Locking: port->mutex has to be held
1836 */
1837static void uart_change_pm(struct uart_state *state, int pm_state)
1838{
1839 struct uart_port *port = state->uart_port;
1840
1841 if (state->pm_state != pm_state) {
1842 if (port->ops->pm)
1843 port->ops->pm(port, pm_state, state->pm_state);
1844 state->pm_state = pm_state;
1845 }
1846}
1847
1848struct uart_match {
1849 struct uart_port *port;
1850 struct uart_driver *driver;
1851};
1852
1853static int serial_match_port(struct device *dev, void *data)
1854{
1855 struct uart_match *match = data;
1856 struct tty_driver *tty_drv = match->driver->tty_driver;
1857 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1858 match->port->line;
1859
1860 return dev->devt == devt; /* Actually, only one tty per port */
1861}
1862
1863int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1864{
1865 struct uart_state *state = drv->state + uport->line;
1866 struct tty_port *port = &state->port;
1867 struct device *tty_dev;
1868 struct uart_match match = {uport, drv};
1869
1870 mutex_lock(&port->mutex);
1871
1872 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1873 if (device_may_wakeup(tty_dev)) {
1874 if (!enable_irq_wake(uport->irq))
1875 uport->irq_wake = 1;
1876 put_device(tty_dev);
1877 mutex_unlock(&port->mutex);
1878 return 0;
1879 }
1880 if (console_suspend_enabled || !uart_console(uport))
1881 uport->suspended = 1;
1882
1883 if (port->flags & ASYNC_INITIALIZED) {
1884 const struct uart_ops *ops = uport->ops;
1885 int tries;
1886
1887 if (console_suspend_enabled || !uart_console(uport)) {
1888 set_bit(ASYNCB_SUSPENDED, &port->flags);
1889 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1890
1891 spin_lock_irq(&uport->lock);
1892 ops->stop_tx(uport);
1893 ops->set_mctrl(uport, 0);
1894 ops->stop_rx(uport);
1895 spin_unlock_irq(&uport->lock);
1896 }
1897
1898 /*
1899 * Wait for the transmitter to empty.
1900 */
1901 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1902 msleep(10);
1903 if (!tries)
1904 printk(KERN_ERR "%s%s%s%d: Unable to drain "
1905 "transmitter\n",
1906 uport->dev ? dev_name(uport->dev) : "",
1907 uport->dev ? ": " : "",
1908 drv->dev_name,
1909 drv->tty_driver->name_base + uport->line);
1910
1911 if (console_suspend_enabled || !uart_console(uport))
1912 ops->shutdown(uport);
1913 }
1914
1915 /*
1916 * Disable the console device before suspending.
1917 */
1918 if (console_suspend_enabled && uart_console(uport))
1919 console_stop(uport->cons);
1920
1921 if (console_suspend_enabled || !uart_console(uport))
1922 uart_change_pm(state, 3);
1923
1924 mutex_unlock(&port->mutex);
1925
1926 return 0;
1927}
1928
1929int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1930{
1931 struct uart_state *state = drv->state + uport->line;
1932 struct tty_port *port = &state->port;
1933 struct device *tty_dev;
1934 struct uart_match match = {uport, drv};
1935 struct ktermios termios;
1936
1937 mutex_lock(&port->mutex);
1938
1939 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1940 if (!uport->suspended && device_may_wakeup(tty_dev)) {
1941 if (uport->irq_wake) {
1942 disable_irq_wake(uport->irq);
1943 uport->irq_wake = 0;
1944 }
1945 mutex_unlock(&port->mutex);
1946 return 0;
1947 }
1948 uport->suspended = 0;
1949
1950 /*
1951 * Re-enable the console device after suspending.
1952 */
1953 if (uart_console(uport)) {
1954 /*
1955 * First try to use the console cflag setting.
1956 */
1957 memset(&termios, 0, sizeof(struct ktermios));
1958 termios.c_cflag = uport->cons->cflag;
1959
1960 /*
1961 * If that's unset, use the tty termios setting.
1962 */
1963 if (port->tty && port->tty->termios && termios.c_cflag == 0)
1964 termios = *(port->tty->termios);
1965
1966 if (console_suspend_enabled)
1967 uart_change_pm(state, 0);
1968 uport->ops->set_termios(uport, &termios, NULL);
1969 if (console_suspend_enabled)
1970 console_start(uport->cons);
1971 }
1972
1973 if (port->flags & ASYNC_SUSPENDED) {
1974 const struct uart_ops *ops = uport->ops;
1975 int ret;
1976
1977 uart_change_pm(state, 0);
1978 spin_lock_irq(&uport->lock);
1979 ops->set_mctrl(uport, 0);
1980 spin_unlock_irq(&uport->lock);
1981 if (console_suspend_enabled || !uart_console(uport)) {
1982 /* Protected by port mutex for now */
1983 struct tty_struct *tty = port->tty;
1984 ret = ops->startup(uport);
1985 if (ret == 0) {
1986 if (tty)
1987 uart_change_speed(tty, state, NULL);
1988 spin_lock_irq(&uport->lock);
1989 ops->set_mctrl(uport, uport->mctrl);
1990 ops->start_tx(uport);
1991 spin_unlock_irq(&uport->lock);
1992 set_bit(ASYNCB_INITIALIZED, &port->flags);
1993 } else {
1994 /*
1995 * Failed to resume - maybe hardware went away?
1996 * Clear the "initialized" flag so we won't try
1997 * to call the low level drivers shutdown method.
1998 */
1999 uart_shutdown(tty, state);
2000 }
2001 }
2002
2003 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2004 }
2005
2006 mutex_unlock(&port->mutex);
2007
2008 return 0;
2009}
2010
2011static inline void
2012uart_report_port(struct uart_driver *drv, struct uart_port *port)
2013{
2014 char address[64];
2015
2016 switch (port->iotype) {
2017 case UPIO_PORT:
2018 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2019 break;
2020 case UPIO_HUB6:
2021 snprintf(address, sizeof(address),
2022 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2023 break;
2024 case UPIO_MEM:
2025 case UPIO_MEM32:
2026 case UPIO_AU:
2027 case UPIO_TSI:
2028 snprintf(address, sizeof(address),
2029 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2030 break;
2031 default:
2032 strlcpy(address, "*unknown*", sizeof(address));
2033 break;
2034 }
2035
2036 printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2037 port->dev ? dev_name(port->dev) : "",
2038 port->dev ? ": " : "",
2039 drv->dev_name,
2040 drv->tty_driver->name_base + port->line,
2041 address, port->irq, uart_type(port));
2042}
2043
2044static void
2045uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2046 struct uart_port *port)
2047{
2048 unsigned int flags;
2049
2050 /*
2051 * If there isn't a port here, don't do anything further.
2052 */
2053 if (!port->iobase && !port->mapbase && !port->membase)
2054 return;
2055
2056 /*
2057 * Now do the auto configuration stuff. Note that config_port
2058 * is expected to claim the resources and map the port for us.
2059 */
2060 flags = 0;
2061 if (port->flags & UPF_AUTO_IRQ)
2062 flags |= UART_CONFIG_IRQ;
2063 if (port->flags & UPF_BOOT_AUTOCONF) {
2064 if (!(port->flags & UPF_FIXED_TYPE)) {
2065 port->type = PORT_UNKNOWN;
2066 flags |= UART_CONFIG_TYPE;
2067 }
2068 port->ops->config_port(port, flags);
2069 }
2070
2071 if (port->type != PORT_UNKNOWN) {
2072 unsigned long flags;
2073
2074 uart_report_port(drv, port);
2075
2076 /* Power up port for set_mctrl() */
2077 uart_change_pm(state, 0);
2078
2079 /*
2080 * Ensure that the modem control lines are de-activated.
2081 * keep the DTR setting that is set in uart_set_options()
2082 * We probably don't need a spinlock around this, but
2083 */
2084 spin_lock_irqsave(&port->lock, flags);
2085 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2086 spin_unlock_irqrestore(&port->lock, flags);
2087
2088 /*
2089 * If this driver supports console, and it hasn't been
2090 * successfully registered yet, try to re-register it.
2091 * It may be that the port was not available.
2092 */
2093 if (port->cons && !(port->cons->flags & CON_ENABLED))
2094 register_console(port->cons);
2095
2096 /*
2097 * Power down all ports by default, except the
2098 * console if we have one.
2099 */
2100 if (!uart_console(port))
2101 uart_change_pm(state, 3);
2102 }
2103}
2104
2105#ifdef CONFIG_CONSOLE_POLL
2106
2107static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2108{
2109 struct uart_driver *drv = driver->driver_state;
2110 struct uart_state *state = drv->state + line;
2111 struct uart_port *port;
2112 int baud = 9600;
2113 int bits = 8;
2114 int parity = 'n';
2115 int flow = 'n';
2116
2117 if (!state || !state->uart_port)
2118 return -1;
2119
2120 port = state->uart_port;
2121 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2122 return -1;
2123
2124 if (options) {
2125 uart_parse_options(options, &baud, &parity, &bits, &flow);
2126 return uart_set_options(port, NULL, baud, parity, bits, flow);
2127 }
2128
2129 return 0;
2130}
2131
2132static int uart_poll_get_char(struct tty_driver *driver, int line)
2133{
2134 struct uart_driver *drv = driver->driver_state;
2135 struct uart_state *state = drv->state + line;
2136 struct uart_port *port;
2137
2138 if (!state || !state->uart_port)
2139 return -1;
2140
2141 port = state->uart_port;
2142 return port->ops->poll_get_char(port);
2143}
2144
2145static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2146{
2147 struct uart_driver *drv = driver->driver_state;
2148 struct uart_state *state = drv->state + line;
2149 struct uart_port *port;
2150
2151 if (!state || !state->uart_port)
2152 return;
2153
2154 port = state->uart_port;
2155 port->ops->poll_put_char(port, ch);
2156}
2157#endif
2158
2159static const struct tty_operations uart_ops = {
2160 .open = uart_open,
2161 .close = uart_close,
2162 .write = uart_write,
2163 .put_char = uart_put_char,
2164 .flush_chars = uart_flush_chars,
2165 .write_room = uart_write_room,
2166 .chars_in_buffer= uart_chars_in_buffer,
2167 .flush_buffer = uart_flush_buffer,
2168 .ioctl = uart_ioctl,
2169 .throttle = uart_throttle,
2170 .unthrottle = uart_unthrottle,
2171 .send_xchar = uart_send_xchar,
2172 .set_termios = uart_set_termios,
2173 .set_ldisc = uart_set_ldisc,
2174 .stop = uart_stop,
2175 .start = uart_start,
2176 .hangup = uart_hangup,
2177 .break_ctl = uart_break_ctl,
2178 .wait_until_sent= uart_wait_until_sent,
2179#ifdef CONFIG_PROC_FS
2180 .proc_fops = &uart_proc_fops,
2181#endif
2182 .tiocmget = uart_tiocmget,
2183 .tiocmset = uart_tiocmset,
2184 .get_icount = uart_get_icount,
2185#ifdef CONFIG_CONSOLE_POLL
2186 .poll_init = uart_poll_init,
2187 .poll_get_char = uart_poll_get_char,
2188 .poll_put_char = uart_poll_put_char,
2189#endif
2190};
2191
2192static const struct tty_port_operations uart_port_ops = {
2193 .activate = uart_port_activate,
2194 .shutdown = uart_port_shutdown,
2195 .carrier_raised = uart_carrier_raised,
2196 .dtr_rts = uart_dtr_rts,
2197};
2198
2199/**
2200 * uart_register_driver - register a driver with the uart core layer
2201 * @drv: low level driver structure
2202 *
2203 * Register a uart driver with the core driver. We in turn register
2204 * with the tty layer, and initialise the core driver per-port state.
2205 *
2206 * We have a proc file in /proc/tty/driver which is named after the
2207 * normal driver.
2208 *
2209 * drv->port should be NULL, and the per-port structures should be
2210 * registered using uart_add_one_port after this call has succeeded.
2211 */
2212int uart_register_driver(struct uart_driver *drv)
2213{
2214 struct tty_driver *normal;
2215 int i, retval;
2216
2217 BUG_ON(drv->state);
2218
2219 /*
2220 * Maybe we should be using a slab cache for this, especially if
2221 * we have a large number of ports to handle.
2222 */
2223 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2224 if (!drv->state)
2225 goto out;
2226
2227 normal = alloc_tty_driver(drv->nr);
2228 if (!normal)
2229 goto out_kfree;
2230
2231 drv->tty_driver = normal;
2232
2233 normal->driver_name = drv->driver_name;
2234 normal->name = drv->dev_name;
2235 normal->major = drv->major;
2236 normal->minor_start = drv->minor;
2237 normal->type = TTY_DRIVER_TYPE_SERIAL;
2238 normal->subtype = SERIAL_TYPE_NORMAL;
2239 normal->init_termios = tty_std_termios;
2240 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2241 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2242 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2243 normal->driver_state = drv;
2244 tty_set_operations(normal, &uart_ops);
2245
2246 /*
2247 * Initialise the UART state(s).
2248 */
2249 for (i = 0; i < drv->nr; i++) {
2250 struct uart_state *state = drv->state + i;
2251 struct tty_port *port = &state->port;
2252
2253 tty_port_init(port);
2254 port->ops = &uart_port_ops;
2255 port->close_delay = HZ / 2; /* .5 seconds */
2256 port->closing_wait = 30 * HZ;/* 30 seconds */
2257 }
2258
2259 retval = tty_register_driver(normal);
2260 if (retval >= 0)
2261 return retval;
2262
2263 put_tty_driver(normal);
2264out_kfree:
2265 kfree(drv->state);
2266out:
2267 return -ENOMEM;
2268}
2269
2270/**
2271 * uart_unregister_driver - remove a driver from the uart core layer
2272 * @drv: low level driver structure
2273 *
2274 * Remove all references to a driver from the core driver. The low
2275 * level driver must have removed all its ports via the
2276 * uart_remove_one_port() if it registered them with uart_add_one_port().
2277 * (ie, drv->port == NULL)
2278 */
2279void uart_unregister_driver(struct uart_driver *drv)
2280{
2281 struct tty_driver *p = drv->tty_driver;
2282 tty_unregister_driver(p);
2283 put_tty_driver(p);
2284 kfree(drv->state);
2285 drv->state = NULL;
2286 drv->tty_driver = NULL;
2287}
2288
2289struct tty_driver *uart_console_device(struct console *co, int *index)
2290{
2291 struct uart_driver *p = co->data;
2292 *index = co->index;
2293 return p->tty_driver;
2294}
2295
2296/**
2297 * uart_add_one_port - attach a driver-defined port structure
2298 * @drv: pointer to the uart low level driver structure for this port
2299 * @uport: uart port structure to use for this port.
2300 *
2301 * This allows the driver to register its own uart_port structure
2302 * with the core driver. The main purpose is to allow the low
2303 * level uart drivers to expand uart_port, rather than having yet
2304 * more levels of structures.
2305 */
2306int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2307{
2308 struct uart_state *state;
2309 struct tty_port *port;
2310 int ret = 0;
2311 struct device *tty_dev;
2312
2313 BUG_ON(in_interrupt());
2314
2315 if (uport->line >= drv->nr)
2316 return -EINVAL;
2317
2318 state = drv->state + uport->line;
2319 port = &state->port;
2320
2321 mutex_lock(&port_mutex);
2322 mutex_lock(&port->mutex);
2323 if (state->uart_port) {
2324 ret = -EINVAL;
2325 goto out;
2326 }
2327
2328 state->uart_port = uport;
2329 state->pm_state = -1;
2330
2331 uport->cons = drv->cons;
2332 uport->state = state;
2333
2334 /*
2335 * If this port is a console, then the spinlock is already
2336 * initialised.
2337 */
2338 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2339 spin_lock_init(&uport->lock);
2340 lockdep_set_class(&uport->lock, &port_lock_key);
2341 }
2342
2343 uart_configure_port(drv, state, uport);
2344
2345 /*
2346 * Register the port whether it's detected or not. This allows
2347 * setserial to be used to alter this ports parameters.
2348 */
2349 tty_dev = tty_register_device(drv->tty_driver, uport->line, uport->dev);
2350 if (likely(!IS_ERR(tty_dev))) {
2351 device_set_wakeup_capable(tty_dev, 1);
2352 } else {
2353 printk(KERN_ERR "Cannot register tty device on line %d\n",
2354 uport->line);
2355 }
2356
2357 /*
2358 * Ensure UPF_DEAD is not set.
2359 */
2360 uport->flags &= ~UPF_DEAD;
2361
2362 out:
2363 mutex_unlock(&port->mutex);
2364 mutex_unlock(&port_mutex);
2365
2366 return ret;
2367}
2368
2369/**
2370 * uart_remove_one_port - detach a driver defined port structure
2371 * @drv: pointer to the uart low level driver structure for this port
2372 * @uport: uart port structure for this port
2373 *
2374 * This unhooks (and hangs up) the specified port structure from the
2375 * core driver. No further calls will be made to the low-level code
2376 * for this port.
2377 */
2378int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2379{
2380 struct uart_state *state = drv->state + uport->line;
2381 struct tty_port *port = &state->port;
2382
2383 BUG_ON(in_interrupt());
2384
2385 if (state->uart_port != uport)
2386 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2387 state->uart_port, uport);
2388
2389 mutex_lock(&port_mutex);
2390
2391 /*
2392 * Mark the port "dead" - this prevents any opens from
2393 * succeeding while we shut down the port.
2394 */
2395 mutex_lock(&port->mutex);
2396 uport->flags |= UPF_DEAD;
2397 mutex_unlock(&port->mutex);
2398
2399 /*
2400 * Remove the devices from the tty layer
2401 */
2402 tty_unregister_device(drv->tty_driver, uport->line);
2403
2404 if (port->tty)
2405 tty_vhangup(port->tty);
2406
2407 /*
2408 * Free the port IO and memory resources, if any.
2409 */
2410 if (uport->type != PORT_UNKNOWN)
2411 uport->ops->release_port(uport);
2412
2413 /*
2414 * Indicate that there isn't a port here anymore.
2415 */
2416 uport->type = PORT_UNKNOWN;
2417
2418 state->uart_port = NULL;
2419 mutex_unlock(&port_mutex);
2420
2421 return 0;
2422}
2423
2424/*
2425 * Are the two ports equivalent?
2426 */
2427int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2428{
2429 if (port1->iotype != port2->iotype)
2430 return 0;
2431
2432 switch (port1->iotype) {
2433 case UPIO_PORT:
2434 return (port1->iobase == port2->iobase);
2435 case UPIO_HUB6:
2436 return (port1->iobase == port2->iobase) &&
2437 (port1->hub6 == port2->hub6);
2438 case UPIO_MEM:
2439 case UPIO_MEM32:
2440 case UPIO_AU:
2441 case UPIO_TSI:
2442 return (port1->mapbase == port2->mapbase);
2443 }
2444 return 0;
2445}
2446EXPORT_SYMBOL(uart_match_port);
2447
2448/**
2449 * uart_handle_dcd_change - handle a change of carrier detect state
2450 * @uport: uart_port structure for the open port
2451 * @status: new carrier detect status, nonzero if active
2452 */
2453void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2454{
2455 struct uart_state *state = uport->state;
2456 struct tty_port *port = &state->port;
2457 struct tty_ldisc *ld = tty_ldisc_ref(port->tty);
2458 struct pps_event_time ts;
2459
2460 if (ld && ld->ops->dcd_change)
2461 pps_get_ts(&ts);
2462
2463 uport->icount.dcd++;
2464#ifdef CONFIG_HARD_PPS
2465 if ((uport->flags & UPF_HARDPPS_CD) && status)
2466 hardpps();
2467#endif
2468
2469 if (port->flags & ASYNC_CHECK_CD) {
2470 if (status)
2471 wake_up_interruptible(&port->open_wait);
2472 else if (port->tty)
2473 tty_hangup(port->tty);
2474 }
2475
2476 if (ld && ld->ops->dcd_change)
2477 ld->ops->dcd_change(port->tty, status, &ts);
2478 if (ld)
2479 tty_ldisc_deref(ld);
2480}
2481EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2482
2483/**
2484 * uart_handle_cts_change - handle a change of clear-to-send state
2485 * @uport: uart_port structure for the open port
2486 * @status: new clear to send status, nonzero if active
2487 */
2488void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2489{
2490 struct tty_port *port = &uport->state->port;
2491 struct tty_struct *tty = port->tty;
2492
2493 uport->icount.cts++;
2494
2495 if (port->flags & ASYNC_CTS_FLOW) {
2496 if (tty->hw_stopped) {
2497 if (status) {
2498 tty->hw_stopped = 0;
2499 uport->ops->start_tx(uport);
2500 uart_write_wakeup(uport);
2501 }
2502 } else {
2503 if (!status) {
2504 tty->hw_stopped = 1;
2505 uport->ops->stop_tx(uport);
2506 }
2507 }
2508 }
2509}
2510EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2511
2512/**
2513 * uart_insert_char - push a char to the uart layer
2514 *
2515 * User is responsible to call tty_flip_buffer_push when they are done with
2516 * insertion.
2517 *
2518 * @port: corresponding port
2519 * @status: state of the serial port RX buffer (LSR for 8250)
2520 * @overrun: mask of overrun bits in @status
2521 * @ch: character to push
2522 * @flag: flag for the character (see TTY_NORMAL and friends)
2523 */
2524void uart_insert_char(struct uart_port *port, unsigned int status,
2525 unsigned int overrun, unsigned int ch, unsigned int flag)
2526{
2527 struct tty_struct *tty = port->state->port.tty;
2528
2529 if ((status & port->ignore_status_mask & ~overrun) == 0)
2530 tty_insert_flip_char(tty, ch, flag);
2531
2532 /*
2533 * Overrun is special. Since it's reported immediately,
2534 * it doesn't affect the current character.
2535 */
2536 if (status & ~port->ignore_status_mask & overrun)
2537 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
2538}
2539EXPORT_SYMBOL_GPL(uart_insert_char);
2540
2541EXPORT_SYMBOL(uart_write_wakeup);
2542EXPORT_SYMBOL(uart_register_driver);
2543EXPORT_SYMBOL(uart_unregister_driver);
2544EXPORT_SYMBOL(uart_suspend_port);
2545EXPORT_SYMBOL(uart_resume_port);
2546EXPORT_SYMBOL(uart_add_one_port);
2547EXPORT_SYMBOL(uart_remove_one_port);
2548
2549MODULE_DESCRIPTION("Serial driver core");
2550MODULE_LICENSE("GPL");